A reprint of annual reports and other papers on the geology of the Virginias

Name: A reprint of annual reports and other papers on the geology of the Virginias
Author: Rogers, William Barton

Rogers, William Barton

A reprint of annual reports and other papers on the geology of the Virginias

Rogers, William Barton · 1884 · Historical

A reprint of annual reports and other papers on the geology of the Virginias by Rogers, William Barton (1884). Full text and reference in the Mountain Man…

Public-domain full text preserved in the Mountain Man Mining Library. Original source: archive.org.

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A Keprint

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Annual Reports

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Geology Of The Virginias.

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WILLIAM BARTON ROGERS, LL. D., Etc.,

DIBXCTOB or THE OSOLOOICAL SUBVEy' OF VIROIKIA FROM 1835 TO 1841; PXBSiOXin OF TUK KATIOHAL AOADSICT OF SOIBKOJn.

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New York: D. Appleton And Company,

1, 8, Amd 5 Bond Street.

CoFTBionT, 1884, By EMMA. B00EB8

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Peeface.

Tns Annaal Beports of the Geological Sarveyj)f Virginia, by Professor William B. Bogers, to the Legislature of that State, were made many years ago, and, although considerable editions were then printed, they hare now become extremely rare. Freqaent requests baying been made, by geologists and others, for these re- ports, it has been thought desirable to reprint a limited number of copies.

Of the Talue of the scientific discoveries, the generalizations and the descriptions of the geological formations contained in these re- ports, there can be no better evidence than the frequency with which they are referred to and quoted by all who are engaged in exploring the geology of the Virginias, and the aid they have given to the de- velopment of the industrial resources of these States, which they foreshadowed, and in fact often clearly pointed out, at a time when the geology of the State was unexplored.

In preparing this volume, the correspondence preliminary to the several reports and the arguments addressed to the Legislature for the continuance of the annaal appropriations, et cetera might have been omitted and the results of the labors of the five successive years have been so arranged as to present under their respective heads all the investigations, of like character, now distributed through the several reports; in adopting the present plan, on the contrary, the results of the investigations are given in the order in which they were made, and at the same time — as interesting to the citizens of Virginia — the history of the relations of the survey to tlie Government is simply told.

Had time and opportunity permitted, it was the intention of the author to revise the several reports, iuoorporating their materials in a single memoir, accompanied by a large geological map and illustra- tive sections, constructed during the progress of the survey.

The geological work of the survey was, by act of the Legislatare, based on the Nine-sheet Map of Virginia'*; but the nse of this map, in the field, proved it to be so grossly inaccarate in its topographical details as to prevent the publication, at the time, of the results of the survey, on a geological map, although the geology was colored on this State map with all the accuracy possible on so imperfect a basis.

It was originally intended to accompany this volume with a large geological map of the Virginias, to be edited by Mr. Jed. Hotchkiss, Geologist and Oivil and Mining Engineer of Staunton, Virginia, from all the geological data left by Professor Rogers. The geological fea- tures of this map are to be colored on a new topographical map which the editor is preparing from information gathered from many sources, the object being to present the geology of the Virginias, as determined by Professor Rogers, on the best topographical map that can at this time be made. Delays, caused by waiting for important topographical surveys now in progress, have made it impossible to publish this map at present, but it is hoped that it will not be long delayed. Meanwhile a small geological map of the Virginias is substituted, it being a reproduction of that which Professor Rogers colored geologically, in 1873, for Mr. Jed. Hotchkiss, to accompany his "Summary of Virginia," published in 1876. No change has been made in the coloriug of this map ; some changes and addi- tions, however, have been made to bring the map up to date, and lines, numbered to correspond with the accompanying geological sections and to show their location, have been added.

The accompanying Virginia geological sections, over ninety in number (see List of Illustrations), except those published to illus- trate special papers, are now made public for the first time. They have been carefully engraved by Messrs. Julius Bien & Co., under the direction and supervision of Mr. Jed. Hotchkiss, from the original manuscript sections prepared by Professor Rogers during the prog- ress of the survey, and subsequently, to illustrate his final report Mr. Hotchkiss writes : No pains have been spared to make these exact reproduction in wfarr ae the geology is concerned, of the see- tione as Professor Rogers left them. No changes have been made except such as Professor Rogers himself made or indicated should be made, by pencil-notes or corrections on the originals. Whenever it has been found necessary to reduce in size any of the sections, such reductions have been made photographically, thus faithfully

preseiriDg the original stratigrapbioal features of the sections. Karnes of places, in the lettering, have been changed to correspond to present nsage."

With these explanations the editor feels that no farther apologj is needed for reprinting the reports and sections unchanged, not- withstanding, to use the words ef the author, they are marked by the immaturity and imperfection incident to annual reports, made at that early period when geological explorations in Virginia were at- tended witli so many difficulties."

In addition to the annual reports, a number of papers relating to the geology of the Virginias have been introduced into the volume.

In the preparation of this work and in the revision of proofs, as well as by many valuable suggestions, the editor has been very greatly aided by Mr. Jed. Hotchkiss, of Staunton, Virginia, and Dr. R. £. Rogers ; she desires also to record her obligations to Professor Kiles and other friends at tlie Institute of Technology, for their kindly interest in the work.

117 Mablborough St., Bobtov, May 188

Letter ot ProfesBor BoroTB to Ilon. B. Johnson Barbour, 1876, in reply to an uigent request from that gentleman for the republication of the AtmniJ BeportB.

Contents.

Pagb

Some ObsoTTations on the Tertiary marl of Lower Yirginia, 1834 1

Beport of Geological reconnoiflsanoe of the State of Yirgmia, 1835 21

Mode of conducting reoonnoissanoe 24

General Geological division of the State 26

Tertiary marl region 28

Miocene marl district 29

Eocene marl district 48

Region between the head of tide and the western flank of the Blue

Ridge 62

Geology, of the Bituminous coal field included in the Primary

region 62

Of the Primary rocks 71

Of the Auriferous rocks 74

Of the Micaceous and other Slates of the region west of the Gneiss 77 Of the Limestone and Marble east of the Southwest and Green

Mountains 80

Of the Rocks, Ores, Soils, Ac, of the region west of the Limestone

as far as the western flank of the Bine Ridge . . . .83 Rocks of the Blue Ridge commencing at the western base of

Turk's Gap 89

Of the Valley of Virgmia 92

Of the North Mountain and Alleghany reon .97

Of the southwestern district of the state Ill

Of the Great Western Bituminous Goal and Salt region .118

Report of the progress of the Geological Survey for the year 1836 . 123 Report of the progress of the Geological Survey for the year 1837 . 147

Miocene marls 151

Eocene marls 166

Description of the several members of the Geolocal Series be.

longing to the region west of the Blue Ridge . . .167

Beport of the progress of the Geological Survey for the year 1838 . 189

Sketch of the Geology of the Appalachian ron of Virginia . 195

Geology of the Valley of Virginia 203

Of the Semi-bituminous Goal of Sleepy Creek, Catawba, Tom's

Creek, ete. 226

Composition of the Magnesian and Hydraulic Limestones of the

Appalachian region 230

The Iron ores of uie Valley and Its Mountains 237

VUl

Report of the progrefls of the Oeological Surrey for the year 1839 . 245

Section I. Operations of the Survey 247

Section II. Tertiary marl region south of the James River . .251 Section III. Southern district east of the Blue Ridge . . .281 Section IV. Of the Middle Secondary Sandstones, Shales, and Con- glomerates of the southern district, east of the Blue Ridge .315 Section V. Operations of the Survey in the Great Western Coal

region 330

Section VI. Operations of the Survey in the region west of the

Greenbriar River and in the Valley of the Kanawha . . 372

Section VII. Operations of the Survey in the Northwestern district 883

Section VIII. Chemical details 864

Report of the progress of the Geological Survey for the year 1840 .411 Chapter L Operations and present condition of the Survey . .418 Chapter IL Tertiary marl region between the Potomac and Rap- pahannock Rivers . .419

Chapter III. The narrow belt extending along the eastern margin

of the Primaiy from Petersbui to the Potomac River . . 437 Chapter IV. Northern district between the Blue Ridge and head

of tide 453

Chapter V. Of the Middle Secondary Sandstones, Shales, and Con- glomerates of the northern district east of the Blue Ridge . 471 Chapter VI. Eastern divisipn of the Southern Primary district and the Coal fields of Chesterfield, Powhatan, Goochland, and Hen- rico counties 480

Chapter VII. Operations in the Great Western Coal region . . 484

Chapter VIII. Chemical details 619

Report of the progress of the Geological Survey for the year 1841 . 537 Analyses of waters of the principal Mineral Springs of Virginia . . 547

.Temperature of Springs 566

Temperature of the air at the Warm Springs and at Richmond . . 566 Subterranean Temperature in the Coal Mines of Eastern Virginia . 567 Connection of Thermal Springs in Virginia with Anticlinal Axes and

Faults 676

The Physical Structure of the Appalachian Chain 599

The Age of the Coal Rocks of Eastern Virginia 643

Contributions to the Geology of the Tertiary Formations of Virginia

(with plates), 18S6 and 18S7 659

Observations on the Natural Coke of the Oolite Coal region in the

vicinity of Richmond . 675

Report on the Pridevale Coal and Iron Ore, West Virginia, 1854 . 679 The Gravel and Cobble-stone Deposits of Virginia and the Middle

States 707

Notes from Macfarlanc's Geological Railway Guide, 1879 . . .715 List of the Ecological formations found in Virginia and West

Virginia 717

Valley Branch of Baltimore and Ohio Railroad . . . .718

Chesapeake and Ohio Railway 719

Virginia Midland Railway 721

Manassas Division of Virginia and Midland Railway . . . 723 Richmond, Fredericksburg, and Potomac Railroad . . . 724

Piedmont and Air-line Railroad 725

Richmond, York River, and Chesapeake Railroad . . . 726

Norfolk and Western Raflroad 727

Seaboard and Roanoke Railroad 728

Waahington and Ohio Railroad 729

Artesian borings at Fortress Monroe, 1882 731

Glossary of Geological and other Scientific terms 787 Appendix :

A. History of the Origin of the Surrey 749

B. Assistants employed on the Surrey 768

C. The Author's reference to a peculiar Iron Ore 763

D. The Author's correction of the arrangement of certain para- graphs 763

K Nitrates in Cave Earths 763

F. The growth of Stalactites in Cayes 764

G. Secondary Formations in Virginia and North Carolina . . 765 H. Unconformity of certain strata in Azoic rocks. . . .769 L Recent names of certain mineral springs of Yiiginia . . 769

List Of Illustkations.

Paob Coluxn Illi7Strati50 Strata In Thb Tsrtxart 276

Fossils from thx Coal Rocks or Eastern Virginia . . . 658

Fossil Shells or the Tertiary or ViRaiNiA. Plates I, II, III, IV, V 673

ILLUSTRATIONS IN FOCKETa

Geological Map of Virginia and West Virginia.

Plate No. I. — Profile section from Chesapeake Bay to the Ohio River, to

aocompan J the Geological Reconnoissance. Plate No. II. — Sections illustrating the paper on Thermal Springs. Plates Nos. Ill, IV, and V. — Sections illustrating the paper On the Physi- cal Structure of the Appalachian Chain. Plate No. III. — Ideal section across the Appalachian Chain.

Section A. — From the Allegheny Mt, Luzerne co., Penn., to the South mt in Berks county. Plate No. IV. — Section B. — From Chestnut Ridge, Indiana eo., Penn., through Armagh and Shippcnsburg, to the South Mt. in Cumberland county. Plate No. V. — Section C. — From Blue Ridge at Ashby Gap, Va., to East- em Front Ridge of Alleghany Mt. at North-Western Turnpike, West Va. Section D. — From the Head of the South Fork of Roanoke Ri?er to

Little Mt., 6 miles from Union. Section E. — From Poplar Camp Mt., at Poplar Camp, to Tug Ridge, west of Abb's Valley. Plate No. VI.— Sections illustrating the Report on ths Pridevala Coal and Iron Ore.

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Platm Nob. VII ahd VIII

GsoLOOiCAL Sbctions in Virginia avd Wist Virginia madb bt Wil- liam B. Rogers during ths Virginia Surtkt, 1836-41, and kn-

GRATED UNDER SUPERVISION Of JeD. HoTCHKISS, 1883-84.

/. Blue Ridge ValUy and Appalaehian SedionA, (Arthaan and

PalcBOZoie.)

No. 1. — Section up Potomac River, from Short Ilill to AUcghanj Mountain

at National Road. No. 2. — Section from observations along Potomac River, from Warm Spring

Ridge to near Cumberland, Md. No. 8. — Section from Blue Ridge, near Vestals Gap, to Eastern Front Ridge

of Alleghany mt., near Grcsaptown, Md. No. 4. — Section from Blue Ridge at Ashby Gap, Va., to Eastern Front Ridge

of Alleghany mt at North- Western Turnpike, W. Va. No. 6. — Section from Blue Ridge at Jeremies Run, by way of Moorefield to

Eastern Front Ridge of Alleghany Mt. No. 6. — Section from Blue Ridge at head of Lower Hawksbill creek, across

Burket-hole mt. to Eastern Front Ridge of Alleghany mt. No. 7. — Section from Blue Ridge at Swift Run Gap, Va., to Beverley in Ty-

gart River Valley, W. Va. No. 8. — Section from Blue Ridge at Rockfish Gap, Va., to Rich mt., north- west of Tygart Valley, W. Va. No. 9. — Section from Blue Ridge at Tyc River Gap, Va., to Greenbrier mt.,

west of Huntersville, W. Va. No. 10. — Section from Blue Ridge at Peaks of Otter, across Rich-patch mt

chain, to Callaghan. No. 11. — Section from Weaver Knob of Blue Ridge, Va., to Sweet Springs,

W. Va. No. 12. — Section from Head of the South Fork of Roanoke River, Va., to

Little mt, 6 miles from Union, W. Va. No. IS. — Section from Little River Gap of Pilot mt of Blue Ridge, Va., to

War Ridge at New River, Fayette co., W. Va. No. 14.— Section from S. E. side of Mack Mt. Range, Va., to Great Flat

Top mt, W. Va. No. 15. — Section from Poplar Camp mt., at Poplar Camp, to Tug Ridge,

west of Abb*s Valley. No. 16. — Section from Point Lookout, Grayson oo., to Tug River, at S. W.

end of Abbs Valley. No. 17. — Section from Iron mt. at Fox Creek Gap, to Coal-field west of Bap- tist Valley. No. 18. — Section from the Coal-field at Sword creek to White Top mt

Xiu

Ka 19. — Section from Stone mi. N. EL to Big Arse mt., on the verge of the

Coal.field. Ko. 20. — Section from Bearer, Tenn., to Guest Station, Russell co., Va. Na 21. — Section from Walker Mt Range, Tenn., to Stone mt at Big Stone

Gap, Va. No. 22. — Section from Blackwater Salworks, through JonesTiUc, to Stone

mt. No. 23. — Section at Potomac River. Na 24.— Section 12 miles & W. of Potomac River. No. 25. — Section at Green Spring Creek. No. 25. — Section at Round Hill, west of Winchester. No. 27. — Section at Fawcett Gap. No. 28. — Section at Sydnor Gap. No. 29. — Section from Little North mt to North River of Cacapon, via

Paddy Run and Oftpon Springs. No. 80. — Section from Little North mt to North River of Cacapon, crossing N. E. end of Paddy Cove.

No. 81. — Opposite Woodstock.

No. 82. — One mile N. E. of Stony Creek Gap.

No. 83.— At Stony Creek Gap.

No. 84.— At Three-mile Mt

No. 85.--S. W. end of Three-mile Mt

No. 36. — Opposite Orkney Springs.

No. 37. — Seven miles N. £. of Brock Gap.

No. 88.— At Brock Gap.

No. 89. — One mile N. E. of Hopkins Gap.

Na 40. — At Hopkins Gap.

No. 41. — At Rawlcy Springs.

Na 42. — Up Briery Branch.

Na 43.— Up North River.

No. 44. — At Augusta (Stribling) Springs.

Na 45. — At Jennings Gap.

Na 46.— At Buffalo Gap.

No. 47.— Six miles S. W. of Buffalo Gap.

No. 48.— At head of Walker Creek.

Na 49. — At North river of James Gap.

No. 50. — At Turnpike 6 miles N. K of Buchanan.

No. 51. — At Rat-hole mt Gap, James River.

Na 62. — Five miles S. W. of James River.

No. 63.— Head of North fork of Catawba Creek.

No. 54. — At Price Turnpike.

No. 56. — Head of Catawba Creek.

Na 56.— At five-mile Fork. Ko. 57.— Three miles N. £. of Peterstown. No. 68.— At Dripping Lick Creek. No. 5.— At New River. No. 60.— Head of Rich Greek. Ne. 61.— Head of Turkey Creek.

No. 62. — Section of Warm-spring mt opposite the Hot Springs. No. 63. — Section of Warm-spring mt. 8. W. of Hot Springs. No. 64. — Section of Warm-spring mt immediately 8. of Warm Spring Val- ley. Nos. 66 to 74. — Sections illostrating location of Thermal Springs.

//. TVofU-AjMdaehian Sedioni.

No. 75. — Section from head of Scott's Mill Run by Morgantown to Laurel Hill on Decker Creek, W. Ta.

No. 76. — Section from North Fork at the mouth of Seneca creek by Clarks- burg to the Ohio River at the mouth of Fishing Creek, W. Va.

No. 77. — Section from Beverley by Weston to Parkersburg, W. Va.

No. 78.— Section from Tygart Valley by Bull-town Salt Works to Parkers- burg, W. Va.

No. 79.— Section from Lewisburg via Charleston on the Kanawha River, to the Ohio, W. Va.

No. 80. — Profile section from Gauley River along the Great Kanawha to the Ohio, W. Va.

No. 81. — Section from Abb's Valley by Logan Court House, to Guyandot on the Ohio River, W. Va.

No. 82. — Section from Clinch River at the mouth of Mill Creek, thence down Tug Fork of Big Sandy River to the Ohio, W. Va.

No. 83. — Ideal section across the Appalachian Chain.

No. 84. — Normal Flexures.

No. 85. — Folded or Inverted Flexures.

Ill, 8edum aeron Midland Virginia (Archaean and Jfeaozaie),

No. 86.— Section from Tuckahoe Creek to Boyd's Tavern (E. S. E. 68 miles).

No. 87.— Section from Falling Creek to CumberUnd C. H. (S. of W. 42 miles).

No. 88. — Section from Petersburg to Raine's Tavern in Cumberland oo. (W. N. W. 69 miles).

No. 89. — Section from Midway by Blue Ridge at Tye River Gap, to Cum- berUnd C. H. (S. E. 68 miles).

No. 90.— Section from Blue Ridge at White Gap, to Sandy River Church

(S. £. 83 miles). No. 91. — Section from Prince Edward G. H. to Railroad 10 miles south of

Petersburg (E. S. E. 74 miles). Na 92. — Section from Delficld to Charlotte C. 11. (W. N. W. 85 miles). No. 98. — Section from Buford Gap, Bedford Co., to Charlotte C. H. (S. E.

76 miles). No. 94. — Section from Belfield to Abbyrilleon Staunton River (W. 72 miles). No. 95. — Section from Halifax C. H. to Weldon on Roanoke River (E. S. E.

98 miles). Na 96. — Section from Blue Ridge at Maggottj Gap, Franklin co., to Halifax

C. H. (a E. 86 mites).

Some Obsebvations

Ov Tbi

Tertiary Marl Of Lower Virginia.

(Fbom m Fabmsbb* Bsobtmb Vol. IL)

On <A6 l}iscovery of Green Sand in the Calcareous Deposit of JEastem Virginia and on the Probable Existence of this Substance in Extensive Beds near the Western lAm- its of our Ordinary Marl,

WlLLUkU ASD MaKY CoiXBOX,

JuM 26, 1884.

To the Editor of the Farmer$ Register :

BiicoB mj AtteDtion was drftwn to the nature and properties of the Mew J&nej green sand, bj the speoimens which jou sent me for aoalysia, and by our more recent conversations on the subject, I have made a yisit to the region in which it is found, and have wit- nessed the most striking evidences of its ntilitj as a manure. During this excursion I examined the marl in all its varieties, and learned many interesting particulars respecting its use frcHn intelligent fiurmers, long experienced in applying it to the soil. I have more- over analyzed several specimens collected on the spot with the view, if possible, of throwing some light upon its agency when applied to the soiL

Binoe my return I have made diligent search for this substance in our marl beds and the accompanying strata, and am at present directing my inquiries to that region of Lower Virginia in which, according to geological laws, as well as from some indications of which I have heard, this deposit may reasonably be expected to occur. As &r as relates to the marl beds of this vidnlty, my search has been unexpectedly successful. With scarce a single exception, I have discovered particles of the green sand, mingled with the ordi- nary sand, day and shells ; and in some instances, in so large a pro- portion as no doubt greatly to enhance the usefVil agency of the calcareous matter. Indeed, I am inclined to believe, that in some cases, the agricultural efficacy of the marl is chiefly owing to the green sand which it contains. In this conclusion I think I shall be sustained by fiicta hereafter to be noticed.

The general occurrence of this substance in our marl beds is cer- tainly a discovery of some interest; and though I may perhaps exaggerate its importance in a practical point of view, I cannot but

think that it.iorthy of the attention of oar farmers. I speak of its generahoiinjiTence, becaose, although I have examined but few specimen .from a distance, toe general resemblanoe of our marl deposit thrSughout, together with the almost invariable presence of the gre'fuir doles in such as I have inspected, would seem to justify the conkision that it is a usual accompaniment of Our marl forma- tion, ibbgh bj no means in equal proportions in all localities. Out of mOfiQ'than forty specimens which I have examined, there were only two in which the green particles could not be discovered ; and they frequently occur in patches, and not generally diffused thVoaghout the bed, it is probable that even in the beds fh>m which /these two specimens were procured the green sand might be else- . .wHere founo. Some of the most efficient marls in the neighbor- ;,\'ikbod of Williamsburg contained a marked proportion of this sub- /stance. At Burwelrs 1011 (Uu'ee miles below the city, towards . / Yorktown) the intermixture is so large that the sand and detritus of shells washed down by the spring fi-eshet display a very distinct greenish olive tinge, which even travellers observe as they pass through the valley in which the deposit exists. At this place the shells, as they are taken out of the extensive bank recently exposed by the torrent, are fi*eqnently filled with a dark mass containing as much as thirty per cent of the green particles. In fact the whole bank is strongly tinged by them ; and the stratum which overlies the shells, in some {uaoes five feet in thickness, is predsely similar to some of the poorer deposits in New Jersey, and contains upwards of thirty per cent of this substance. In Judge Semples marl beds, in the same vicinity, the green particles are equally abundant — and as in the former oase extend into the incumbent stratum of non- calcareous matter. In many instances this layer of overlying earth has been found even more efficacious on the soil than the subjacent marl — a fact which might naturally be inferred, when the green particles abound chiefly in the upper stratum, from the extraordi- nary efficiency of the green sand as experienced in New Jersey. But by fiir the most interesting locality of this substance, in point of extent, which I have examined, occurs on the shore of James River, adjacent to King's Mill and LitUetown. Here the banks rise per pendicularly to the height of from forty to sixty feet, and for about three fourths of this elevation are composed of shells and earth, mingled with a large proportion of the green sand, which in some places imparts a distinct color to the surface. The sand of the beaoh is also filled with these particles, which the rains have washed down, and which at first view present the appearance of tiie common black sand of our river, though in much larger quantity. At Bellefield, and other places on the York river, the banks and beach are simi- larly impregnated.

The green particles may be readily recognized by their want of lustre, the ease with which they may be bruised with the point of a penknife, and the bright green stain which they then produce. In examining earth or marl in which they are very sparsdy scattered, the partides are sometimes difficult to separate from the other mat-

tor. My method is to moisten the end of the knif( bUide hj apply- ing it to the toDgae. and then to remove several of the particles bj a&esion. When placed upon a card and bruised, thej leave a brill- iant stain. ThtB test may be confidently relied on.

The occnrrence'of the green sand bo extensively through oar marl regioni affords strong groands for hoping that valuable beds of this sabstance, like those of New Jersey, almost entirely nnmingled with other matters, may be brought to light by a jndioioas and enter- pring examination of the district on the western limits of oar mm. And shoold such a discovery be made, the agricnitore of Lower Virginia would become possessed of a new and powerful auxiliary in farthering its already rapid career of amelioration. Even the fact that the green sand often exists in c<Hisiderable quan- tities in and above our ordinary marl beds, which is, I think, now suffioiently established, may furnish no unimportant aid in the im- provement of our lands, by leading to a more varied and judidous adaptation in the application of oar manures.

Independently of the existence of the green sand in a scattered state in our caloareoas strata, there are other and stronger reasons for believing that a deposit similar to that in New Jersey will be found in the appropriate region. In a geological arrangement of oar various formations, the marl beds of Eastern Virginia and Oaro- lina, as well as those of Maryland, belong to a later period in the physi- cal history of our country tiian the green sand formation of New Jer- sey— the former being referred to tiie Tertiary, and the latter to the Secondary epoch of geologists. Now this tertiary deposit extends into New Jersey, and is found in many places in the latter state near- ly contiguous to the green sand. Moreover, indications of the New Jersey formation have been found in Maryland ; and such is tibe genend regularity with which the different geological deposits are arranged, that we may fairly infer the existence in Eastern Virginia of the green sand, or some deposit eauivalent in a geological point of view ; though, at the ssme time, it by no means follows that the green ssad, if actually found, would be snfficientiy near the surface to render it extensively available as a manure. Tbe object, bow- ever, is of such magnitade as to justify a very diligent examhiation, and I am therefore, desirous of enlisting in this resesrch all those readers of tbe Register" who reside in tbe region which has been alluded to before. As, however, the success of this investigation will be greatly promoted by an acquaintance with tbe indications by which the grwn sand or its geological equivalents are to be rec- ognised, and some knowledge of the properties and constitution of the substance itself, I shall here give a orief account of the New Jersey f<Mination which I visited, together with the result of several chemical analyses of the sand carefully executed by myself and oth- ers ; and further to interest your readers in this important inquiry, I shall add a statement of such facts bearing upon the application and agency of the marl as I was enabled to collect during my visit to the beautiful region which it has so largely contributed to fertilize and adorn.

The New Jehej green sand is apparently identical with that ries of deposits recognized in Enrope by the name of the green sand formation, characterized by a predominance of minnte green par- ticles in many of its strata. In Enrope these strata are generally fonnd alternating with beds of chalk ; bat in this coontry no chalk is fonnd, nnless iu the renon West of the Mississippi. The fossils embedded in the green sand on both sides of the Atlantic are, how- CTer, so strictly alike, that the geological equivalence of the Ameri- can and European beds can scarcely admit of qnestion, and is thqe- fore generally conceded as an established point. It is relevant here to remark that in tracing ootemporaneons or equivalent geological formations in different regions, geologists are accustomed to rely almost ezdnrively npon the fossils, whether shells, bones, or yege- table remains, which the strata may contain — a procedure to which they have been led by the whole tenor of modem developments in geology. Now with reference to the New Jersey formation, thongh it would be impossible without numerous drawings and much de- scriptive matter, nninteresting to general readers, to convey a knowl- edge of even the principal shells and other fossils existing in the green sand, some account of a few of these fossils may possibly be nseful in the inquiries which I trust many of yonr readers will be prompted to undertake :

1st. Lignite or carbonized wood, often associated with iron pyr- ites of a bright yellow lustre, frequently occurs in the beds over- lying the green sand formation, though it sometimes occurs in other situations.

2nd. Aniber is often found in a similar position, as was the case at the Delaware and Chesapeake Canal.

8rd. Belemnitey a fossil of a yellow or brown color, in shape somewhat like a cigar, but rather thicker — very brittle, and usually found broken transversely so as to exhibit its tubular character within.

4th. Ammonites a fossil presenting the appearance of a snake coiled up in a flat coil, and frequently large and ponderous.

6th. The Echinus, or Sea-urchin, sometimes globular, at other times much flattened, having numerous little warty prominences, and minnte perforations symmetrically arranged on its surface, and when entire, occasionally furnished with spines or prickles.

6th. OrypJuKa a shell having one valve very deep and convex, and the other flat. It somewhat resembles the small shell {Ghama) very abundantly fonnd in our marl beds. This latter is smaller — has a rougher exterior, and has two mnscnlar impressions in each valve — whereas the Oryphma has but one.

7th. Bxogyra, a shell like the former, with one convex and one flat valve — but a great deal rougher and more irregular in aspect, and of large dimensions.

8th. The Falcated Oyster a beantifnl shell abont one and a half or two inches in length, and bent like a Turkish scimetar.

These rude descriptions, which have no pretensions to scientific accuracy, are designed to draw attention to such fossils as may be

bronght to fight in the region in which the green sand may be ez- pectiMl to occur — and in this point of view may prove of reel value in examining for that deposit. Of course a scientific inspection of the foanlfl would be necessary to establish tiidr identity, but this can readily be procured by transmitting them to the Academy of Sciences in Philadelphia, or by sending them to William and Mary, where they would be carefully examined and compared with the New Jersey fossils as collected and described. Indeed there is reaaon to believe that some of the characteristic fossils have already been found in Eastern Virginia. A bed of Lignite has been lately discovered on the Rappahannock, a few miles below Fredericks- burg, the very point at which it might be expected to appear; and from information reoentiy received, I am disposed to believe that Belenmites may be found near the mouth of Potomac Greek. It has been said' also that the Chrypluta has been found, but I have not heard in what vicinity. These facts should furnish an addi- tional stimulus to inquiry, and literally no stone should be left un- turned in pursuit of so important a discovery.

The Dew Jersey green sand is generally found in the valleys and meadows, though occasionally it rises to some height in the sur- rounding hills. Its depth in many places is very great, and several strata occur, separated by layers of shells, or blue clay, or sand colored by iron. The general aspect of the greeu sand is that of a bank of moist bluish clay — thougn in some places the green tint is very perceptible. This however only occurs where the earth is dry. When thrown into heaps by the side of the pit, the mass foils into a coarse powder, in texture and color very closely re- sembling gonpowder, on which account it is very commonly known by the name of ffunpawder marl. This mass conrists in very large proportion of tiie pure green saud, having a slight ad- mixture of clay, and in many places of minute fragments of shells. Oocadonally, the bank presents a mass of the pure green sand itself— and again, in some places the shells predominate. In one of the in the vicinity of New Egypt, I discovered small fpiculsa of gypsum, or sulphate of lime: but this occurred at no other locality — and in this place the crystals were so minute and few in number as to require the use of a microscope to be seen distinctiy. The moist marl, when warmed in the hand, exhales a strong phosphoric odor, a fact which 1 believe has not been hitherto remarked.

already obeerved, the marl frequently contains shells, both in an entire and broken condition. This however, is by no means universal. In fact, the great majority of those beds in actual use contain either no calcareous matter, or a very minute proportion of it. This I ascertained by chemical examination. In the vicinity of Amey's Town, CroaswiokV Creek, and Shrewsbury, as well as other placea, much of the marl which the farmers spread over their land contains no carbonate of lime ; while at New Egypt the calcareous and non-cakareous marls are both extensively employed. The same is true, likewise, of the beds farther south, at Mnllioa HiU. The

green partides themselves have an invariable compoation — and uiose of oar Virginia marl beds are perfectly identical with those of the New Jersey deposit. Thirty grains of the green sand yielded by careful analysis:

Silica, 15.51 grains.

Protoxide of iron, 7.56 "

Potash, 8,10

Water, 8.00 "

Magnesia, a trace.

These results agree very closely with the detennination of Rer- thier of France, and Seybert of Philadeiphia. The former operated upon the green sand of Europe, the latter upon that of New Jersey. It appears therefore that the predominant constitnents are silica and uzide of iron. The potash, amounting to about ten per oenL is most probably the ingredient chiefly concerned in the agricultural agency of the marl, though in what way its connection with the other ingredients is severed when the marl is spread upon the land, I am at a loss to coigecture.

Throughout all the district in which this deposit occurs, it is ex* tensively employed in agriculture. In the neighborhood of Amey's Town, one of the points which I visited, it has been used as a ma- nure for the last thirty years — but its general introduction is of more recent date. In the region in which the marl chiefly abounds, the soil is loamy, having in some places a large intermixture of tenar cious clay. East of this tract, which is a narrow band nearly paral- lel to the Delaware River, the country assumes an appearance very similar to that of the sandy lands of Eastern Virginia, covered with a thick growth of pine, and comparatively unproductive. On both these varieties of soil the green sand is continually used with the most striking benct. For the clay soils, the more sandy marls are of course prefenred; and for the sandy soils, those which ocmtain some day along with the marl. The proportion in common use uear Arney's Town, is from ten tor twenty loads per acre. In other places five loads or even less is found to be suflndent. The action of the marl appears to be very permanent, as will be evinced by the foUowing statement. In a large quadrangular Add over which I walked, four successive applications of the marl had been made at intervals of four years — commencing about twenty years ago. The first dressing was applied to the north side— the second to the south — the third to the east, and the fourth to the west — while a small space in the centre was left widiout any marl. All four sides were cov- ered with a heavy crop of clover, which was nearly, if not quite as luxuriant on the north as either of the other sides, while the space in the middle was almost bare. The action of the marl appears to be most powerfully felt by dover and grass, but it is very conspicu- ous also with small grain and com. A very intelligent farmer told me that it more than tripled his dover and grass crop, and doubled his small grain.

In general it is spread upon the dover every fourth year, and ploughed in for the next crop. That it is very efficient on sandy soils

is evinced hj the following striking fact. Some jears ago an enter- priaing farmer near New Egypt, porobaaed two hundred acres of the Fine Barren, which, bj marling, he has converted into pastare enffident for one hundred head of cattle. Such is the demand for the marl, even at a considerable distance, that it has become an article of great profit to the proprietors of the pits, and more than one IndiTidoal was pointed ont to me who had risen to wealth bj the sale of marl.

From what has been stated it will at once be evident that the disoovery of extensive and accessible beds of this manure in Vir- ginia would be a most important accession to the resources of the state, and that an actiee and diligent search ought forthwith to be commenced throughout all the region in which there is a probabil- itj that it exists. Every aid wfaioh it is in my power to give, will be cheerftiUy bestowed in furtherance of this inquiry: and as I feel the double interest of a scientific curiosity, and a sincere solicitude for the agrioultnral prosperity of our state, I shall gladly receive all fossils and other specimens which may be transmitted for inspection or analysis, giving them a prompt attention, and communicating in reply such hints as may promise to be most useful in this deeply in- teresting and important investigation.

Wm. B. Roosrs.

ApparaJtiUB for analyzing Marl and the Carbonates in gen- eral.

WiLUAM AiTD Mart Collbgs, Jvne 27, 18S4.

To the Edit&r of the Farmenl* Regi$t&r :

The apparatus which I am about to describe, is intended to give greater accuracy and facQity to the usual process for determiniog the Quantity of carbonic acid in marl, or in any of the carbonates. By the common method, the two vessels containing severally the marl and the muriatic acid are placed in one of the scales of a delicate balance, and there counterpoised by weights put into the other scale. The acid is then poured upon the marl, and after all the carbonic acid has been dischargea. the equilibrium is restored by adding whts to one, or absdnicting them from the other scale. In principle, this method is entirely free from objection: but as usually conducted, it can not be relied upon as accurate. This want of precision arises, in the first place, from the escape of aqueous vapor, along witii the carbonic acid which is discharged, thus making a greater weight necessary for restoring the equilib- rium, than IS due to the quantity of carbonic acid which baa escaped — and seccmdly, from the greater weight of the vessels containing the marl and acid impidring the sensibUity of the balance, and thus rendering it impossible to estimate the carbonic acid to small frac- tions of a grain. The first of these ejections has long been obvi?

ated in the chemicfd analysis of the carbonates, by cansing the gas as it escapes to pass through a tube containing dried muriate of lime : and the latter has been in some measure removed by a oontriyauoe of the great practical chemist Rose ; which, however, as it is inoon* venient and uncertain in the manipulation, I shall not here de- scribe.

The apparatus which I have devised, is, I think, free from these objections, and enables the operator to proceed with great accuracy and despatch. It has the advantage of being very easily constructed, and of being used with a balance that can be procured at a very moderate price. Moreover, the quantity of marl which is necessary for experiment in no case exceeding ten grains, specimens for analy- sis may be easily forwarded by letter.

The balance which I use with this apparatus is a small gold- smith's balance— such as may be procured for a few dollars in New York. It is very light, and turns, when unloaded, with the of a grain. My set of weights, obtained from Millington in Philadel- phia, extends to tenths and hundredths of the grain.

The accompanying figure will convey a distinct idea of the ap- paratus and mode of using it. One of the scales is removed to admit of suspending the apparatus by a double thread over the hook of the beam. The other is made of something light, as a piece of card. In this way all unnecessary weight upon the beam is avoided, and its sensibility preserved.

A, is a light bulb of glass, blown very thin from a common piece of tube, and about one inch in diameter. A cork is fitted to its mouth, and through this the tapered ends of the bent glass tubes, B and G, are passed air tight ; the extremity of the latter extending some distance into the vessel. The tube B, through which the gas escapes, is filled with fragments of muriate of lime. The tube 0, which contains the muriatic acid, is furnished with a light piston of cork or cotton, in the centre of which is fixed a rod or handle made of a small stiff straw. This instrument, when charged with marl and aciil, does not weigh more than 120 grains. The whole load of the beam is therefore 240 grains, and it is still sensible to the of a grain.

The mode of proceeding with the analjais is as follows. Five or ten grains of tbe finely powdered marl is introduced into the vessel A, and then two or three drops of water added to assist the diffusion of the aoid. The small end of the tube O, now removed from the cork, is dipped into some muriatic acid in a wine glass, and the piston moved backwards and forwards until the necessary quantity of add has been drawn in. The tube is then replaced in the cork, and in this state the instrument is counterpoised by weights in the op- posite scale. The piston being then gradually forced in, the acid is mjected drop by drop, upon &e marl, and the gas escapes by the tnbe B, depositing the aqueous vapor in its passage, on the muriate of lime. Allowing the apparatus to rest untU the gas has entirely escaped, and the decomposition is complete, the equilibrium is re- stored by placing weights upon the clear top of the cork, or by removing weights from the scale. In this way the weight of the disengaged gas is accurately determined, and the proportion of car- bonate of lime thence computed.

An analysis of a specimen of marl from James City, just com- pleted, will serve as an illustration of the method. Ten grains of the finely powdered marl was introduced witli a little water into the vessel A, the instrument was then charged and equipoised. The add being injected, the whole was allowed to rest for an hour. The weight lost was 2.91 grains. Increasing this in the ratio of 44 to 100, gives 6.61 grains of carbonate of lime in the 10 grains of marl— or almost predsely 66 per cent

The frequent calls upon me for the analysis of specimens of marl, first led me to the construction of this apparatus, and I have nnce found it so convenient and'accurate, that I can recommend its adop- tion to such of your readers as may have a taste for chemical in- quiries connected with agriculture. Any ordinary worker in glass will construct the instrument, and skill in manipulating with ic may be soon and easily acquired.

Wm. B. Rogers.

(FmoM TBI Fasirbs' BjiiI8Teb op Mat, 1886.)

Mifiher Observations on the Green Sand and Calcareous

Marl of Virginia.

Is a communication published in the third number of tlie Register/' I announced the discovery of the greensand, or silicate of iron and potash, in the ordinary tertiary marl in Lower Viiginia. GhK>logical considerations, taken in connection with this discov- ery, led to the inference that an older deposit, consisting in much larger proportion of this pecaliar substance, wonld be found in a region more remote from the seaboard, and not far below the head of tide; and from the great agricultural value of this substance, as

S roved by the experience of the farmers in New Jersey, 1 was in- noed to point out its probable position, and to give such hints and

direotioos with regard to its aocompan jing indications as might prove nsefnl in any researehee whiob might be undertaken bj persons residing in the region in which it was supposed to exist. Sinoe the pablication of the paper referred to, as far as other engagements wonld permit, this important inquiry has been actively continaed, not only in reference to the presamed deposit above mentioned, bnt also to the extensive oaloareoas formation of oar lower connties.

Besides the practical importance of this investigation to the agricaltare of a large district of the state, in a purely geological aspect, it was calculated to excite the highest interest. In the vast region of our tide-water country, at farthest, only two members of the tertiarff group of formations had been hitherto discovered, and no decided indications of a seemiiary deposit lilcely to prove inter- esting to men of science, bad been found. At the month of the Potomac, and at some other points, a deposit had been detected by Mr. Oonrad of Philadelphia, which from the great predominance of shells of exUting 9peeieSy was regarded by him as belonging to the upper or newer tertiary. The same eminent conchologist, by an examination of numerous fossils frotii York town, Suffolk, the James River, near Smithfield, and other locditiea, had clearly proved that this portion of the tertiary series was of greater antiuuity than the former, and accordingly he has recently applied to it the title of middle tertiary — which, as some geologists in Europe divide the tertiary group into f&ur periods, would include both the second and third of these sabordinate formations. The lower tertiary, which Mr. Conrad had so successfully investigated in Alabama, had not as yet been brought to light within the limits of Virginia. Thus, there- fore, these inquiries appeared fraught with the hvcdy interest of scientific discovery, while at the same time they inspired the ani- mating hope that in some of their results they might eventually be found conducive to the interests of an important district of the State.

From the great extent of the middle tertiary of Lower Virginia, it was to be expected that, notwithstanding the diligence and learn- ing of those who had visited several of its interesting localities with the view of studying its fossil contents, an extensive field of future discovery would be opened to the scientific explorer — and a great variety of new and peculiar fossils would be brought to light. To a certain extent this anticipation has been realiz ; and the occa- sional examinations which I have made in this vicinity, and at some remote points, have been rewarded by an extension of the list of fossils, and the discovery of a number of now and interesting species. To the readers of the Register,' generally, the details of these ob- servations would appear unimportimt, if not useless, and must there- fore be omitted. At the same time, I may be allowed to add, that such facts are frequently invested with a praetieal intereU by tlie aids which they furnish to other and more important discoveries; and that, however little value in the abstract wonld attach to an enumeration of the shells, zoophytes, and other remains of our marl banks, they are absolutely essential in studying the physiod history of this portion of the globe, and may prove of some assistance, not

only in gnlding the researohee of the farmer after marl, but in direct- ing his choice of calcareous manure, when various depceits of this nmtanee are offered for his selection. Of the latter point, several striking illustrations might be adduced — but I shall content mysf, for the present, with tlie statement of a single fact. A small shell of rough exterior and rather irregular form, a species of ehama, is frequently found in very extensive beds in this vicinity and at other

faints, forming nearly the entire calcareous portion of the deposit, rom its pecufiar form and friable character, it is most generally in a condition to be eminently serviceable as a manure. As the strata both above and below are often of a very different texture, though perhaps nearly equal to it in regard to their calcareous contents, a choice is at once presented to the farmer, in which he will be guided even more by the nature of the shell embedded than by the com* parative abundance of carbonate of lime. But so little attention lias been paid to the character of the fossils contained in our marl banks, that even in places where the manure has been longest and most successftiUy in use, a less valuable stratum is sometimes selected in preference to one of superior fertilizing power. A more minute observation of such particulars can scarcely be expected in the ab- sence of some popular guide, in the form of delineations and descrip- tions of the more prominent shells, exempted as much as possible from technical or merely scientific phraseology. Some snoh illus* trations may hereafter be furnished in a cheap form in the progress of a geological examination of the eastern region of our state.

Since the publication of my former paper, a great number of additional observations have been made with reg to the green sand contained in our ordinary middle tertiary marl. Its unorm presence in this deposit, in a greater or less proportion, seems now to be sufficiently establied. That it is generally present in suffi- cient quantity to enhance in any important degree the agricultural utiHty of the manure, it would be going too far to assert; but that in many cases the proportion is such as cannot fail of producing highly beneficial effects upon vegetation, would seem to be demon- strated, not only by the long experience of the farmers of New Jer- sey with the green sand itself, but by the observations of individuals among ourselves who have been in the habit ci applying a calcare- ous marl in which this substance is peculiarly abundant. In the vi- cinity of Williamsburg, almost every variety of the common marl may be found ; but that w hioh has been observed to produce the most strik ing effects as a manure, has uniformly yielded to chemical examina tion a comparatively large proportion of the green sand. When there- fore, it is in the power of the farmer to make the selection, such marl should be chosen, as, along with a large proportion of calcareous mat- ter in a suitable state of subdivision, contains also as great an amount as possible of this auxiliary numure. The beds of ehetma already re* femd to, as abounding on rame estates in this vicinity, are pecul- iarly rich in this ingredient, and are hence, as well as from their friable texture, generally selected in preference to all others. In some of tiiese deposits, as large a proportion as thirty, and in some

specimens forty per cent, has been found ; and in cases like this, if we are to trust the experience of New Jersey, a very marked addi- tion to the fertilizing power of the marl mnst be ascribed to the presence of this ingredient.

In alluding thns to the influence of the green sand as an auxil- iary manure, the inquiry naturally ariseis to which of its ingredi- ents are its meliorating effects to be ascribed, or do they arise from the conjoint action ot the potash and oxide of iron which it con- tains ? To this inquiry, perhaps, it would be premature to attempt to respond. At all events, the rationale of its action can not be given with that certainty which in such matters, it is desirable to attain. As stated in the former communication, its components are protoxide of iron, potash and silex ; the latter ingredient appearing to act, as it is known to do in many rocks, in the capacity of an acid. In virtue of the potash contained in the green sand, we would naturally infer an agency in neutralizing acids similar to that of lime, or its carbonate and the extent to which the manure pos- sesses this property, must appear still further increased when we advert to the chemical natiyre of the protoxide of iron.

Iron, like most other metallic bodies, combines with oxygen in more than one proportion. These compounds, or axide$ as they are termed, are two in number, and in accordance with the general rule adopted by chemists in designating this class of substances, that which contains the least proportion of oxygen, is called the protox- ide, that containing the most, the peroxide. The rnst of iron, and the red coloring of ocbreous clays, and of bricks and tiles, are im- pure specimens of the peroxide of iron. The protoxide is never found in an uncombined condition ; and such is the avidity with which it imbibes an additional quantity of oxygen, or unites with carbonic and other acids, that it undergoes a rapid change when- ever disengaged. Hence, under favorable circumstances, a strong neutralizing action might be anticipated from this ingredient the green sand. We may therefore, for the present, rest our ex- planation of the agency of this manure upon the alkaline proper- ties of these two constituents, the potash and the protoxide of iron. But in suggesting this explanation, it must be freely confessed that, especially as relates to the action of the protoxide of iron, it must be looked upon as problematical, and requiring for the establishment of its truth, an experimental knowledge of the influence of this sub- stance upon the growing vegetable, of which nothing has as yet been positively determined.

As already indicated, when these inquiries were entered upon, and at the time when my flrst communication appeared in the Regis- ter,*' the existence of a lower tertiary deposit in Virginia had not been ascertained. The industry of Mr. Conrad had brought to light a formation of this nature in Alabama, and had led to the probable inference that it existed at Fort Washington in Maryland. Moreover, one or two of the fossils obtained from the editor of the Register encouraged the hope that it might be found in our own state. The observations of that gentleman respecting the gypseous earth of

James River had appeared some time before, and thoagh nothing positive ooald be gained from them, in relation to the geological character of the deposit to which he affixed that name, they threw oat the important and sagacioas snggestion, that this earth was the same with the green sand of New Jersey, or at least a sabstance of analogous character. We shall in the sequel, learn that though geologically the two formations belong to periods which are dis* tinct, the pseons earth contains a large proportion of that partic- nlar ingredient, (the green silicate of iron and potash), of which the New Jersey deposit almost exclusively consists. We are therefore indebted to the editor of the Register," for the announcement of the important fact that the green sand, or a substance analogous to it, existed in certain localities on the James River.

Following up the suggestions of geological analogy, alluded to in my first paper, and stimulated by the observations and stotements of Mr. Roffin, I have been enabled by personal iospection, and through the kindness of correspondents, to ascertain with cer- tainty, the existence of a lower tertiary deposit throughout an ex- tensive district of Eastern Virginia, and moreover to determine what is far more important to the agriculture of this region, that the deposit in question comprises immense strata of green sand,

Jerhaps nearly equal in value to that which is in use in New ersey. The reader, however, is by no means to infer from the ex- istence of the green sand so abundant, both in this lower tertiary and in the New Jersey formation, that the two deposits belong to the same geological era. I have already stated that the New Jersey green sand is a teeondary deposit, and of course anterior to the formation here designated as lower tertiary. The shells and other fossils, entombed in the two deposits are strikingly different, and characteristic of difference of geological antiquity. As it is desir- able that clear ideas should be entertained, in relation to the distinc- tion here drawn, I would claim the indulgence of the reader in pre- senting such explanations and illustrations as are calculated to throw light upon a subject in which, at least in some particulars, all are obviously interested.

The term primary having been adopted by geologists as design noting that extensive class of rocks which from various indications, appeared in general to have originated and whieb are destitute of all traces of animal or vegetable existence— the title of eeeondary was of course appropriated to a class, apparently of more recent origin, usually overlying the former, and in which, in many cases an enormous accumulation of organic remains had been discovered. A minnte examination of these remains, consisting of shells, the bones of animals, etc., disclosed the curious fact that they belonged to races of beings of which at present there are only a very few living representatives. Subsequent ol>servations, first systematically made by Cuvier and Brogniart in tlie vicinity of Paris, further demonstrated that, overlying the Secondary formation of that region, there existed an extensive series of deposits of great thickness, the fossil contents of which were, on the whole, very dissimilar ttovi

those of the former— not onl j aU the §pecie$ but manj of the most remarkable animal and vegetable forms being distinct, while at the same time many of the spedes were obseryed to be identical with others now all ve. The difference thns marked between the two series of deposits, nniformlj prevailing wherever they were observed, led to the introduction of the term tertiaryfy to designate the upper and more recent By scrutinizing in detui the tertiary series, it was soon discovered to consist of several distinct subordinate formations, characterized by peculiar fossils, and becoming more assimilated in their organic contents to the existing living world, in proportion as their position in the series approadied nearer and nearer to the surface. The most recent systematic writer on geology, and one of the most learned and able geologists of the day, has distinguished four subordinate formations in the tertiary series — and has given to each a specific name expressive of its relative period of deposition. Though unwilling to perplex the reader with the terms of science, I may perhaps be excused on this occasion for introducing the names here referred to, on the ground that they are likely to be met with frequently hereafter in geological descriptions of the tertiary deposits of this country — and as they are distinctive of UUngt which are characteristically different, and which have received no other denominations so appropriate, they have a just claim to be received. The terms tiins employed by Mr. Lyell, the distinguished geologist above alluded to, are —

Ist. Plioeene, indicating a nuorUy of the c<mtained fossils to be reeenty and divided into newer and older Pliocene. Under this head are comprised some of the shell deposits near the mouths of our rivers.

2nd. Miocene indicating a mtnmly of the contained fossils to be recent. To this formation belong most of our calcareous strata which have previously been referred to under the title of middle tertiary.

8rd. Eoeenej signifying the dawn; indicating the presence of a few fossils analogous to living species, or in other words a dawning of that condition of the animated world which now prevails. Exam- ples of this are fhmished in the lower tertiary of Alabama, and the lower tertiary here alluded to as recently discovered in Virginia.

The nature of the materials in which the fossils of these differ- ent deposits are embedded is very various. Sometimes the forma- tion is a soft sand or clay — sometimes a sandstone or limestone of comparative hardness. In some cases the deposition appears, from the nature of the fossils, to have been made beneath the ocean- sometimes at the bottom of an extensive lake. In the vicinity of Paris, there are three marine formations alternating with two of fresh water or lake origin ; and from one of the latter, the celebrated gypsum or plaster of Paris is extensively quarried. In Virginia no traces of a fresh water tertiary have as yet been discerned. The general direction of the deposit is horizontal, and the whole appears to have been formed at successive eras beneath the waters of the ocean.

From what has now been said, it will at once appear that strong

features of resemblanoe are presented in the geology even of the more recent formations in this country and Europe. The most striking similarity exists between the Secondary of New Jersey and that of the Paris bssin — as far as foasii contents are concerned. Bnt in £arope a great proportion of these fossils are embedded in chaJk ; whereas, in New Jersey, no chalk has been discovered, and its place is occupied by green sand, very shnilar to that which, in the f(iner localities, alternates with the layers of chalk.

The lower tertiary or eocene of Virginia, is found in a band of Tariftble and as yet unascertained breadth, traversing the state nearly in a direction from north to sooth. It makes its appearance on both sides of the Potomac, in a line a little east of irederioks- bor It Uien crosses the Kappahannock near Port Royal, the Pamonkey probably near Piping Tree, and the James River at Coggings Pomt. With regard to the ooorse fartiier south, though its existence is probable, additional data are required.

In general character, this fonnation may be thus described. At the base of the cliff or bank, there usually exists a stratum of what at first sit appears to be a blue or black clay, but which, on further examination, is found to cousist prindpaUy of particles of the sili- cate of iron and potash, which when dried, becomes of a lively green color. Mingled with this substance are portions of common day and sand, and numerous minute, shining scales of mica. Em- bedded in the mass, and usually in a very friable condition, numer- ous shells chiefly of small dimensions will be found. Sometimes however, the matter of the shell has entirely disappeared, leaving a distinct oast or impreflsion in the earth, by which its specific charac- ter may often be ascertained. Immediately above this stratum is a heavy deposit of what Mr. Rnflin has desoribed as gypseous earth. Large masses of crystallized gypsum, and sometimes the most bean- tifuT groups of perfect crystals of this substance, are disseminated throughout this layer. It was this portion of the formation which Mr. RufStn conceived to be identical with the green sand of New Jersey. In color, this stratum varies from a greenish yellow to a brown. Besides a considerable proportion of green sand, it con- tains, in addition to the crystallized gypsum, a notable amount of this substsnce in a subdivided state, and seemingly occupying the place of the shells which were formeriy present, and have been decomposed under the chemical agency of some substance which filtrated in solution through the mass. Incumbent upon this bed is a thin layer of very pure white clay, of a texture which would recommend it to various useful purposes. Overlying the clay in some places, is a stratum of shell marl in a very subdivided state, con- taining masses of oasts and sheUs approaching to the hardness of rock. This is the uppermost layer of the eocene or lower tertiary formation. Tet at some points a stratum of the ordinary middle tertiary mari rests almost immediately upon the former, and would not by an ordinary observe be recognized ss distinct At Tarbay, where this suocesrion of strata was observed, a thin and scarcely dis- tinct layer of small brownish red pebbles intervenes between these

two layers of shells, seeraing to Tnark a oomptradvelj violent action of the waters in the interval of the two deposits. Bat an examina- tion of the shells, in these two contignous strata, affords abundant evidence of their belonging to distinct geological epochs. In the upper stratum the large scallops, the common oyster of our marl, and all tiie usual ingredients of our middle tertiary or miocene formation, may be recognized. In the lower bed few or none of them exist, but certain characteristic shells belonging to the eocie period are entombed. Similar fossils appear below, in the green sind beneath the gypseous earth ; and here a gpreat variety of buti- ful specimens may be discerned. An enumeration of these fossils in this place would of course be attended neither with utility nor interest, and indeed, were it advisable in the present stage of the inquiry, it could not be made, on account of the necessity of com- paring the specimens with shells from other localities in Europe and this country, in order to identify species, aud to decide upon those which are new, or peculiar to our own formation. That many such exist, I have every reason to believe, and with future leisure it is hoped that they will be named according to the fashion of the day, and described in the appropriate place.* It will however be of real value to the reader, in any mquiries which he may institute in refer- ence to this formation, to obtain some general idea of the charaoten of two or three of the more conspicuous and characteristic shells. The observer will perhaps be able to recognize the following —

Ist. The Oardita planieosta. This shell is of various sizes, rarely however equalling that of the dam. In form it bears some resem- blance to that shell; but on the convex side a number of flattened ridges run from the knobbed extremity near the hinge, spreading from each other and enlarng as they approach the margin. The hinge part of the shell is very thick. This shell occurs abundantiy in the eocene or lower tertiary of Europe, and also in that of AUir bama.

2nd. Oitrea ullaformu or saddle-shaped oyster. This shell is very peculiar, having, when full-grown, such a lateral extension on each side as to present, when the hollow of the shell is turned down, a very distinct resemblance to a saddle with its two depending flaps. It is found abundantly in the eocene of Alabama.

8rd. Futu longimUy a small shell less than an inch in length, and resembling in general form those which are commonly called conchs. It is however flattened down on one side as if it had been subjected to pressure. This shell occurs abundantly in the eocene of Europe, but I believe has not until now been discovered in the correspond- ing formation of this country.

These three fossils, which are all found in great numbers in such of the eocene localities in Virginia as I have examined, are suffi- cient to identify the formation wherever they may be discovered. But as already indicated, they are accompanied by a variety of

♦ These Bhells were described by W. B. Boffers and H. B. Kogen in m series of contributions to the American Philoeophical Sodety, 1886, 1887 and

other shdls, a large proportion of whloh would appear to be pecul- iar to thia partioalar region. It would seem that the eocene of Virginia though agreeing with that of Alabama, contains some foeeils found so in the Paris eocene, and whloh are absent from that of Alabama.

In most of the specimens of marl from this region hitherto examined, besides a large amount of green sand, I have found a considerable proportion of gypsum, and in some of them as much as forty or fifty per cent of carbonate of lime. Specimens received from Dr. Corbin Braxton, at the Piping Tree, were found to con- tain, along with much green sand, a great amount of carbonate of lime, and some gypsum. Judging from its composition and texture, it must be lookea upon as a very valuable manure. At Coggings Point, the lower stratum before described, contains from sixty to seventy per cent of the green sand, with a small proportion of car- bonate of lime, and occasionally a little gypsum. The next deposit above, (the gypseous earth), abounds in gypsum, but contains less green sand than the former. Of this ingredient, however, it still possesses a very considerable proportion. In alluding to the pow- erful effects of the gypseous eartn, in a trial which he made, the author of the Essay on Calcareous Manures describes them as much greater than could be accounted for by the proportion of gypsum present, and hence throws out the suggestion that some other fertilizing ingredient was contained in the earth. This addi- tional effect must doubtless be ascribed to the presence of the green sand.

In prosecuting the Geological Survey of Maryland, Professor Ducatel has been enabled to ascertain the existence of a green sand deposit throughout an important district of that state. Of its existence on both sides of the Potomac I was already fully aware and it affords me much satisfaction to find that the suggestions, based upon general geological considerations, which were presented in my former paper, have already been so actively and ably followed up by this enlightened and diligent observer. Of the identity of some of the green sand deposits described in his report, with that now ascertained to exist in the eocene of Virginia, I am as yet by no means convinced ; but a minute geological examination, such as that already instituted in Maryland, and that which is looked to with some interest in Virginia, cannot fail to throw very useful light on this, as well as all the other important deposits in the tide- water region of the two states. Mutual benefit would arise from the co-operation of surveys, conducted at the same time in the two adjoining territories, and in this way the interests of the states, as well as those of science, would be most effectually and speedily promoted.

To the very meagre details, in relation to the green sand, pre- sented in this communication, I may hope ere long to be enabled to add the results of extensive and minute personal observation in the interesting region in which the eocene formation has been de- tected. In the mean time, the progress of inquiry may be

ftiiibered by the friendly aid of those who, from their residence in the region in question, will have it in their power readily to collect specimens of shells or earth, and to transmit them to me for in- spection. I would therefore, earnestly solicit assistance of this kind, and in retam, I will gladly communicate the results of any observations I may thus be enabled to make. To urge the im- portance of this aod other similar inquiries would now no longer seem to be necessary — since large portion of the intelligence and enterprise of our state appears prompt to recognize their value, and interested in furthering their aotive and successful prosecution.

Wic B. Room.

Eepoet

Of

The Geological Eec0Nn0Is8Ance

or

The State Of Vibginia,

Kade Under The Appointment Of The Board

Of Pubug Works, 1836.

Office of the Board of Public Works,

January 11, 1886. To the Botue of Delegates :

I HAVE the honor to transmit herewith a report of the geological reoonnoisBance, made in the State of Virginia during the past year, by Professor Rogers, of the University of Virginia, whose reputa- tion as a geologist and chemist, induced the l>oard without hesita- tion to appoint him to make the said reconnoissance.

The report is accompanied by a map, exhibiting a profile and physical section of the country from tide- water to the Ohio. I am, very respectfully, your most obedient servant,

Littleton W. Tazewell, President of the JBoard of Fublie Works.

Report.

GnirTLSMSN : I beg leave to present the following report of the geological reconnoissance of the State of Virginia, authorized by an act of the legislature, bearing date March 6th, 1885, with the execu- tion of which I have had the honor to be entrusted.'

In the prosecution of this duty, while my attention has not been withheld fom such observations of a minute and detailed descrip- tion aa opportunities occasionally tlirew in my way, it has been chiefly directed to the legitimate objects of such a reconnoissance ; namely, the general geological and mineralogical features of all the important divisions of our territory, with a view to exhibit the benefits to be derived from a detailed survey, and the mode of con- dnctiog it best adapted to develop the structure and resources of tiie state. Although, in the course of these enquiries, many new observations have been made calculated to prove extensively advan- tageous, numerous matured discoveries were not to be anticipated, oonmdering either the design of the reconnoissance or the very general nature of the investigations which are appropriate to an examination strictly preliminary in its character. Enquiries of a more minute description, extended to all the divisions of the state, would obviously have been impossible, and until some scheme of systematic investigation in detail is put in operation, comparatively of little value. With such views, it is thought that the objects of the reconnoissance are accomplished, in exhibiting the prominent geological features of the great divisions of the state, the more im* portant natural resources dependent upon their mineral structure, and in pointing out in relation to each the various desiderata to which future enquiry may be beneficially directed.

♦ See Appendix.

Mods of coin>nonKo the Sscohnoibsavok.

With the view of exhibiting dearly the geological stmctare and relative extent of the varions formations in the state as as ascer- tained during this reconnoissance, it was important to oonstract what is termed a geological teetion or profile, from actual observa- tions made, from point to point, in one or more lines transverse to the generid ranges of the strata ; thns combining in one view, tH the most important mineral formations of the state, together with their prevaihng order of succession, and their relative incBnations, or the angle in which each inclines to the horizon. The genend line of observation selected for this purpose, extends from Hampton Roads to the mouth of the Gujandotte. A belt of country of vari- able breadth, spreading to some distance on either side of this Une, was the more immediate subject of investigation, and furnished the materials from which the geological section >pended to the present report was constructed.

In prosecuting the examinations necessary for this purpose, no one line of observation was rigorously adhered to, but numerous local profiles were first formed, and thence, by a reference of them all to the general line already specified, the entire profile was formed which is now presented. It is, therefore, tenderea at this time only as an approximate delineation of a transverse geological section of the staite, and as such, though sufficiently accurate for the purposes of occasional reference in tiie present report, lays no claim to the minute precision of geological profiles constructed from the accurate data of a detailed survey. Several minor belts, also transverse to the general ranges of strata, and remote from the former, were like* wise examined, and particular profiles constructed from the data lus obtained. One of these extends in a general direction from the White Sulphur Springs, by Covington and Lexington, to Bucking- ham Court-Honse; a second from Columbia, by Charlottesville, Turk's and Rhodes* Gap, and Harrisonburg to the North mountain; and a third embraces a portion of the Potomac In addition to these transverse lines of observation, several routes have been ex- plored more nearly conforming to the bearing or direction of the strata. One of these extends in a general direction from Halifax, on the Roanoke, to the lower falls of the Potomac, and is nearly coincident with the western boundary of the tide water or tertiary section of the state. Another embraces a general view in the lonai- tudinal direction of the Valley of Virginia, from the Potomac to the James River, etc. Besides these, many other lines of observation were examined, some of them embracing a distance of fifty or sixty miles on dther side of the general route. Keeping in view the im- portant practical enquiries appertaining to the reconnoissance, bb much local information of a useful nature has been obtained on each excursion as was consistent with the time which could be devoted to investigations of a special character. The general nature of the

obsenrations contemplated in tlie reconnoissance, and the necessity of rapid movements when so great a breadth of formations was to be traversed, rendered mnch delay in mlnote local observations in- expedient, on which account many points of great practical interest wUl be excluded from the report, which might otherwise have been introduced. These would be among the proper subjects of enquiry in a detailed survey.

In regard to the tide water section of the state, it is proper to remark, that through some previous attention to its geology, I am enabled to present a somewhat minute account of its important fea- tures, as observed in several large and interesting districts which I have explored, among which I would specify the peninsula bounded by the York and James rivers, and many of the counties on either aide. More recently and in eonnection with the reconnoissance, I have examined the country on both sides of the Pamunkey, from the junction of the Korth and South Anna to its mouth, and have extended my enquiries with some success into similar formations south and north, as far as the James river and the Potomac. The discovery of a material likely to prove valuable to the agriculture of that section of the state may, without impropriety, be referred to as an illustration of the utility to be expected from minute geological enquiries directed to every portion of our territory.

But in addition to the duty of exploration performed according to the plan which I have now described, 1 have devoted some time to the chemical analysis of rocks, ores, earths, marls, and mineral waters. In relation to this department of my duties, however, it is easy to perceive that the tedious nature of such investigations would preclude the completion of many accurate analyses within the period allotted to the reconooissance ; but a variety of useful chemi* cal results have been obtained, which, as far as compatible with the scope and objects of this report, will be detailed in the following pages.

Genebal Geological Division of the State.

For the sake of exhibiting under one view each group of analo- gous formations, the whole territory of the state may be conven- iently divided into five principal regions. These we will treat of in a geographical rather than geological order; first defining the limits of each respectively, with as much precision as in the imper- fect state of knowledge on the subject can be attained, and then in general terms describing the geological features by which they are, to a certain extent, severally distinguished :

1. The first of these, which may be called the Tertiary marl re*- ffiari, embraces nearly all that portion of the state included between its eastern boundary, the Chesapeake bay, and the Atlantic, and a hypothetical line intersecting the principal rivers at their lowest fidls. Various beds of clay and sand, nearly horizontal in position, abounding in fossil shells and the remains of large marine animals, form the characteristic strata of this division of the state ; while

oocafdonal bands of iron ore and beds of green sand and a small portion of gjrpsum, occurring in connection with one of the fossil- iferoQS deposits of the region, are among its other materials of value.

2. The second division is comprised between the hypothetical line above mentioned and the western flank of the Blue Eidge in- cluding under this title the range very improperly denominated the Alleghany mountain in Franklin and Patrick counties. According to the delineation of Mr. McOlnre, by whom the first attempt was made at marking out the great geological divisions of North Amer- ica, the rooks of the Blue Ridge and a narrow adjacent belt of terri- tory should be regarded as belonging to the primary system of geolo- gists ; while a large portion of the area between this and the belt of unequivocally primary character, which ranges along the lower falls of our rivers on the east, is to be looked upon as the equivalent of the Old Red Sandstone rocks of Europe. Others, who have at- tempted to sketch the outlines of our principal geological forma- tions, have, with even less approach to accuracy, confounded all these strata under the sweeping denomination of primary, and have thus given to the diversified and extensive region whose limits are above described the distinctive appellation of the primary region of Virginia. Such a view appears to have been adopted by the authors of the map of oar state, the brief geological ssetch appended to which describes the Blue Ridge as the western boundary of the primary. A more recent writer also, professing to derive his views from an actual examination of the structure of this mountain, has contributed to confirm the prevailing error by proposing as an ap- propriate name for the Blue Ridge the title of the Atlantic primary ehain.

It is deeply to be regretted that while so little has been done toward a minute exploration of the diversified and complex forma- tions of the region now in question, the writers who have attempted to describe it, and more especially those who have professed to give a scientific exposition of its character, should have observed so little caution in the application of names, and have indulged so much of the spirit of superficial and precipitate generalization. There is no division of the state which presents greater difficulties to the geo- logical enquirer than the region here referred to, and none which will reauire for its elucidation more minute and patient investiga- tion. Ihe observations respecting some parts of it, which will be presented in the body of the report, imperfect as they necessarily have been, were directed in part to the determination of some of the diflScult problems which this portion of our geology presents, and although insufficient to remove the difficulties in which this subject is involved, will, it is believed, lead to several interesting and important views of a scientific as well as practical nature, while they overthrow the errors which, either through ignorance or inadequate investigation, have hitherto existed. So far from recarding the whole area in question as of a primary character

theso observatioDs conclasiTely demonstrate that the extent of the rocks, to which that title may be nnequivocally applied, bears bat a small proportion to the whole surface of this division of the state — and while they render it donbtfol whether in the Blue Ridge any truly primary rocks occur, they evince the existence in that range, as well as throughout a very extensive di>trict to the east, of sand- stonen, conglomerates, and other sedimentary deposits, unquestion- ably referable to a different period of formation.

The gold region, so remarkable for its extent and richness, and the bituminous coal fields of Chesterfield, Goochland, Pow- hatan, and Prince Edward, constitute important divisions of this region of the state ; while the slates and soapstones, iron ores, lime- slonea, and other minerals which it includes, are objects of practical as well as scientific interest. To all of these a proper place will be allotted in the body of the report.

8. Our third general division, commencing near the western fiank of the Blue Ridge, comprises all the region generally called The Valley, extending westward in the counties of Berkeley, Fred- erick, Shenandoah, and Rockingham, to the base of the several ranges called the Little North mountain, in Augusta and Rock- bridge, nearly to the base of the North mountdn and in the conn- ties farther south, occupying an area which, for the present, does not admit of being accurately defined. Limestone strata of vast ex- tent, hydraulic lime, marble, travertine or deposit marl, slate, iron ore, and in the south lead ore, are among the valuable materials included in this section of the state. Declining to apply the title of Transition to the strata of which this region is composed, be- cause much additional observation is required for the determination of their true geological relations, we must for the present be content with referring them to the oldest of that group of rocks in which organic remains or fossils have been discovered.

4. The fourth general division to which we shaP refer is, atpres- est, even less susceptible than the preceding of being defined by lines of precise limitation. Nearly the whole of its suiface is occu- pied by chains of mountains, and extremely little has hitherto been done towards exploring its geology. In general, it may be described as comprised between the western limits of the great Valley forma- tion and the front ridge of the Alleghany, the Greenbrier, and Muddy Creek mountains ; but with regard to its extent and boundaries far- ther south, nothing definite can be afiirmed until it shall have been (Arefully and systeuiaticnlly explored. Besides the interest in a sc-i- entific point of view which attaches to this region on account of the peculiar structure of its mountains, the stupendous natural sections' which it exposes, and the astonishing abundance and variety of the foml impressions found among its rocks, it claims a high importance from the great value of its materials, economically considered. Its anthracite, pseudo-anthracite, or semi-bituminous and bituminous coals, its limestones, sandstones and grits, and iron ores, and its numerous thermal, chalybeate, and sulphuretted springs, constitute

collectively an amount of mineral treasures of which few other territories of the same extent are as largely possessed. Without, at present, ventaring to apply any precise geological designation to this singularly interesting region, it will be shown to have marked peculiarities which distinguish it from the division pre- viously described.

5. Our fifth and last division, stretching from the eastern limits of the former to the western and southwestern boundaries of the state, presents an area of vast extent, and embraces regions abound- ing in materials of the highest economical utility.

This immense territory, characterised by nearly horizontal strata, gently dipping toward the west, refers itself unequivocally to the group of secondary rocks — and from the numerous and rich beds of bituminous coal which it includes, may with strict propriety be denominated the great secondary bituminous coal region of Virginia. Besides its numerous and widely stretching strata of the above men- tioned materia], this favoured region possesses the additional treasure of a saline formation of immense extent, toward its western bound- ary— and if the limits of the region are not improperly assigned, a similar formation, accompanied with gypsum and other valuable minerals, in the southwest corner of the state.

Pursuing the order in which the several divisions of the 8tate have now been sketched, the Tertiary marl region will first claim our attention.

Tebtiaby Mabl Kkgion.

The extensive area embraced in this division of the state, though presenting comparatively little diversity in external aspect, includes strata which by their fossil contents unequivocally refer themselves to two distinct geological periods, though they are all, without doubt, comprised in the general class of tertiary formations. Adopting the names which have been recently applied in Europe to parts of the tertiary series, to which the strata referred to may be regarded as probably equivalent, though without implying any con- viction on our part that such equivalence is in general to be ex- pected in the two continents, we shall indicate by the term Miocene the strata which occur in the eastern and greater portion of this region, and from which the ordinary shell marl is procured ; while wo will apply the name Eocene to the deposit of an older date, exist- ing beneath and west of the preceding, containing fossils of a 4f- ferent character, and characterized by the prevalence, in consider- able proportion, of the peculiar mineral called green sand.

The first of these, or the Miocene marl district comprehends all the area from the sea board or water boundary of the state on the east, to a line conceived to be drawn through Northbury on the Pamunkey, and Coggin's Point on the James river, in a direction nearly meridional ; but through what precise points, further obser- vations are necessary to determine.

The other, or Eocene marl difttrict is comprehended between the

imacoary line above described and another line passing from the month of Acquia creek, through Wales, at the juDction of North and South Anna rivers, and thence through City Point, and farther sonth in a direction not yet precisely ascertained. Much of the district here defined exhibits Miocene as well as Eocene marl, the former being found either in highlands remote from the rivers, or in the superior parts of the river cliffs overlying the latter. The localities above named were selected as points marking the eastern boundary of this region, because at those places the £ocene marl was observed to disappear below the water line by a gentle dip to the east. Its existence extensively beneath the Miocene district may be looked npon as highly probable, though under what circum- stances as to depth and inclination of the beds we have no positive data to determine.

MiooEXR Ma EL District.

In the most eastern portion of this division of the tertiary, the general level of the surface is but little elevated above tide. The country is a nniform flat, in some places subject to be occasionally overflowed. The rest of the region in question has an elevation above tide varying from twenty to eighty feet. But few points, however, in the district have a level corresponding to either of these extremes, and by far the larger portion of the surface preserves a height of from forty to fifty feet.

The surface of this more elevated portion, though preserving a general level of remarkable uniformity, is deeply channelled by in- numerable ravines. The smaller of these connect themselves with large ones, and these with the wider and deeper excavations forming the beds of the creeks flowing into the neighboring rivers. The system of ravines connected with one river is separated by a nar- row central tract from that connected with the next, and in a general view of the diittrict, these systems present the appearance of mere creeks or inlets subordinate to the great rivers by which this region is broken into peninsulas. The number and extent of the large rivers and the navigable streams of this portion of the state constitute the most inestimable of its natural advantages. The numerous creeks indenting its peninsulas furnish the cheapest and readiest avenues for a commerce which comes home to the abodes even of its rural inhabitants ; while ito surface, scooped into ravines, and its river cliffs washed by the tides, disclose the rich mate- rials which are hereafter to bestow the highest rewards upon its enterprise, by spreading fertility and wealth to its remotest bound- aries.

llie superficial stratum of the region we are describing is an argillaceous and ferruginous sand, of a yellow and sometimes of a reddish color, in which are occasionally foun<f, at or near the sur- face, pebbles and small boulders of sandstone, rarely as nmch as six inches in diameter. The nature of these boulders would indi- cate that they were most probably derived from the sandstone for-

mation which ranges along the eastern bonndarj of the primary- ridge. In 8ome places this stratum consists of little else than a white silicioas sand ; in others, the admixture of ochreons clay is so considerable as to furnish a suitable material for the manufacture of bricks.

Beneath this superficial layer, beds of a very argillaceous clay occasionally occur, sometimes of considerable depth and extent, and of a texture to be useful in puddling. Its color is yarious, being in some places of a dark blue or green, in others of a bright red or dingy yellow. Wherever found, its upper boundary is remarkably even and horizontal ; but where it rests upon beds of fossil shelU, its lower limit conforms to all the irregularities of surface which those beds usually present. Its appearance, in some places, is that of a steep, almost perpendicular wall of smooth surface, and divided by very narrow lines running horizontally. These narrow lines, at a distimce of from five inches to a foot asunder, are formed by a more ferruginous and silicious clay. At Bellefield, on the York river, seven miles from Williamsburg, this deposit may be seen overlying the stratum containing shells, in some places having a thiclmess of from twelve to fifteen feet, and then gradually fining out and passing into a light colored and coarser mass. The upper surface is horizontal, and the lines of division above alluded to are perfectly parallel and regular. The lower surface of the clay con- forms to that of the shell stratum upon which it rests. In many places these argillaceous beds consist of a yellowish clay, beautifully variegated by streaks of blue and red. In some places there exists a slight impregnation of alum nd copperas in these beds of clay. This is particularly the case in some localities on the Rappahannock and the York and Chickahominy rivers. The proportion of these ingredients is however not sufficiently great to entitle these strata to attention in an economical point of view, although it is fully suf- ficient to impart a very ungrateful flavor, and perhaps some useful medicinal properties, to the springs and wells of the neighborhood.

A thin stratum of red ferruginous stone, containing a large pro- portion of oxide of iron, is found in this region, running horizon- tally below, and sometimes in the beds of clay before described, and generally separated by only a few feet from the underlying masses of shells. This stratum, which is very generally present, varies in thickness from an inch to a foot. Its texture is sometimes cellular, sometimes compact and fibrous, like that of certain varieties of hematite. In the more eastern portions of the Miocene district, the peculiar structure of which will be hereafter described, much ore of this description lies loosely scattered on the surface ; while in the more elevated parts of the country its invariable position is such as above described. The character of the ore in many localities is such as to promise great facility in reducing it to the metallic state, together with a large percentage of resulting metal. A specimen obtained from above the marl on the cliff at Mount Pleasant, Surry county, yielded by analysis in the 100 grains:

Peroxide of iron, 72.40

Ainmina, 8.90

SiUca, 7.71

Water, 14.85

Loss. 1.64

With a sufficient supply of ore like this, accompanied with the advantage of a hell limestone, sometimes beaotiniUy crystalline, in its immediate vicinity, the raanafaoture of iron would promise a lii{h degree of productiveness, and it is by no means improbable that in some parts of this region the supply of the ore may be found sufficient to make such an enterprise not only safe but profit- able. The subject is at all events w;orthy of some attention. In- deed it appears not a little surprising that this rich mineral seems hitherto to have escaped observation, or at least to have been re- garded as undeserving of an especial notice.

In some places, as for example in Essex county, chiefly upon tiie ridge land, beds of a ferruginous sandstone are found of saf- ficient extent to be used as a building material. This rock is not to be confounded with the sandstones which occur some distance to the west of this, on the borders of the primary region, but it is to be looked upon as in the case of a very similar material recently made the subject of minute inquiry by my brother in New Jersey, as a remnant or outljring portion of a once some- what extensive deposit of ferruginous gravel and conglomerate, which by subsequent denuding action has been almost entirely removed.

The matter which in most cases rests immediately upon the shells, is a yellowish brown sand, frequently containing a large pro- portion of clay. Throughout this mass, and often extending to the distance of five or six feet from the shells, particles of green sand, or the silicate of iron and potash, are more or less abundantly dis- seminated ; and in the immediate vicinity of the shells these parti- cles are generally condensed into narrow stripes conforming in flex- ure to the irregularities of the bed beneath. Even where a deep hole exists in the layer of shells, the stripes of green sand are seen still following the depression and rise of the surface, and preserv- ing a uniform distance from it. Sometimes these thin layers are so much indurated as to have almost the appearance of stone. In none of the strata above described have fossils of any description ever been discovered.

The materials with which the shells are intermixed, or in which they are embedded, have various characters. In some cases they consist principally of a nearly white sand ; in others the argillaceous matter greatly predominates, and the mass is a somewhat tenacious

olay. Frequently much oxide of iron is mingled with the eartliy matter, giving it more or less of a yellow or brown appearance, and this is the aspect which the upper beds containing shells most usu- ally present. Very generally the lowest visible fossiliferons stratum is composed of a green silicious sand, and a bluish clay, which being always very moist, is soft and tenacious, and presents a dark blue or black color. At the base of the cMs on the James and York rivers, this stratum may be traced continuously for considerable distances, rarely rising more than two or three feet above the level of the water, and presenting an even horizontal outline. In the deep ravines, and low down in the banks of shells, generally, throughout this region, a similar dark bluish green argillaceous sand is observed, encloing frequently a great number and variety of shells. This constitutes what is usually denominated blue marl whioh, from the soft condition of the shelly matter it contains, as well as the predominance of clay in its composition, is found pecul- iarly beneficial when applied to the more arenaceous varieties oi the soil. Many highly valuable marls, extensively in use, are of this description.

The very general existence of the lower stratum, above described, forms an interesting and prominent feature in the geology of the Miocene Tertiary districts, as well of Eastern Virginia as of Mary- land. Throughout all the upper fossiliferons strata, as well as in the argillaoeous beds just mentioned, will be found disseminated, greenish black grains of silicate of iron and potash identical with those already described as existing in the stratum immediately over- lying the shells, and having the same form and composition with the granules contained very abundantly in an older formation, both in this country and in Europe. In some beds of the marl or shells, these particles so abound as to give a very decided color to the whole mass. In specimens from James City and York counties, as much as thirty-five per cent of the green sand has been found, and occasionally shells are seen filled with this substance almost alone.

The surface of the strata containing shells is usually irregular. Sometimes it rises abruptly in the form of a hillock, then it is scooped out into depressions of a few feet in depth. These irregu- larities, however, are apparently of two kinds : the one the original form of the deposit, the other produced by denuding action upon the surface. Thus in many places the same stratum may be re- marked rising with more or less abruptness, then again descending and perhaps preserving a nearly horizontal line for some distance,, marked at its upper surface by a clear and unbroken outline, and presenting no indication of violent abrasion from above. In other places, and this is a very frequent occurrence, deep and irregular furrows and cavities are seen, such as would naturally arise from the action of the currents and eddies of a large mass of water in rapid movement. Whether from this cause, or from the gradual dissolving action of percolating water, sinks exist in this region in

many plaoea, tboogh they are by no means aa namerons or ezten- aive as in tbe limestone districts.

Having tbas given an accotmt of tbe nature and arrangement of the strata overlying the shells, as well as those in which they are embedded, we will now describe the general condition and dispo- sition in which the shells occnr.

Condition of the Shells in the Tertiary Deposits.

In general, the state of the shells and their arrangement in the earth are such as to indicate their tranqnil deposition at the spot where they are found. Thus the corresponding valves are very often fonnd together and closely shnt. Many of the smaller shells, snch as Area centenarian Area ineile, Nueula, Venerieardia alti- caeta and Chama congregate which are most usaally foand thus, are often entirely empty, or contain a small quantity of clay that ia quite impalpable, indicating plainly that they have been exposed to no violence, and that only snch solid matter as could pass between the edges of the closed valves had obtained access to the interior. Whenever such shells, however, have been previously drilled, as ia very frequently the case, even with the largest and thickest shells, the interior is fonnd entirely filled with sand, clay, green sand, and small fragments of shell. In most cases the larger species of shells, even when their valves appear to be in accurate juxtaposition, are thns filled, and in this case it cannot be supposed that the contained matter has entered through the holes thus drilled, since in many instances shells of considerable maffnitude are found imprisoned within. Snch shells, no doubt, after the death of the animal, remained open, or at least partially so, and received the sand, clay, and other materials which they contain, by the gentle action of the waves. The ligament at the hinge in the mean time would decay, until at length, yielding to the pressure of the accumulating matter above, tbe shell, in favorable circumstances would collapse into its natural closed condition.

The very common occurrence of the valves in juxtaposition, is a striking proof that during or subsequent to their deposition they have not been exposed to violent agencies. This becomes even more remarkable in the case of snch shells as the Panapea reflexa, which almost in every instimoe is found with the valves properly united. The connection between the two valves in this shell is the slightest imaginable, after the destruction of the natural organic bond, and an inconsiderable force would have sufficed to separate and break the valves.

The admirable preservation of the shells in many cases is also an interesting fact, and affords another evidence of the absence of all violent agencies at this period. The most fragile species of Natiea delicate Tellina Maetra tellinoides, the shell and processes of the Crepidula, the minute and sharp angles of the Fusus tetricusy the thin and hollow Fissurella — are found in perfect preservation in many places. The state of the shells seems to depend chiefly npon

the mechanical texture and chemical character of the materials in which thej are mixed, and of which the overlying stratum is com- posed. In the moist blue clay the shells are generally found in a yery soft condition. In a highly ferruginoas clayey bed they are found either partially or entirely dissolved, and beautiful casta re- main in their stead.

In many places entire banks occur, composed of easts of Chama and other shells, sometimes separate, sometimes cemented together so as to form a species of rock. These appearances occur chiefly near the surface, and when the soil is porous and ferruginous. The casts thus formed often consist cliiefly of carbonate of lime, and in many specimens as much as eighty per cent of this substance ik found. Oasts of this kind belong mostly to the smaller shells, and by far the most common are of the Chama eongregata. These, ns already stated, are often found nearly or quite empty, and we may, therefore, conceive, that as the matter of the shell in an extensive bank of Chamas is gradually dissolved, the water, charged witli carbonate of lime, enters the cavities, and slowly deposits the car- bonate, mixed with fine particles of clay and sand. Thus, by de- grees, the cavities are filled. In the mean time the shell disap- pears, frequently leaving on the surface of the cast a chalky cov- ering, like the decomposed inner film of shelly matter. In support of this explanation it may be added, that in many casts beautiful crystals of carbonate of lime are found, forming a portion of the cost, and having the appearance of Dog-tooth Spar, In some cases the shelly matter appears to have been dissolved, and its place sup- plied by the crystallized carbonate, incrusting the earth formerly contained within the shell. Sometimes, too, a thin film of oxide of iron surrounds the cast, showing very distinctly all the markings of the inner surface of the shell. In many localities, presenting a series of beds dilfering in composition, the shells will be found per- fect in some of them, while in others, immediately above or below, only casts remain. Thus at the College Mill, about one mile from AVilliamsburg, the upper fossilit'crous layer is a yellow silicions sand, containing perfect shells. Below this is a brown ferruginous clay, filled with the most beautiful casts of Chama PectunculvSj Tur- ritella etc. The shelly matter has entirely disappeared, and the casts lie loosely in the cavities produced by the removal of the shells, entirely distinct from each other, and covered by a film of oxide of iron. The layer beneath, consisting of bluish green sili- cious clay, is full of well-preserved Pectens, Pemas, and a variety of other shells.

In general, the various species of shells are found associated in colonies or groups, but as in the case of banks of recent shells, these colonies contain many scattered specimens, difi:ering f rom the general contents of the group. The two species of Chama the C. congregata and (7. corticosa which are found in almost every deposit of shells in this region, in many cases form extensive beds, with a very small admixture of other genera. The best agricnlturid marl, of a purely calcareous nature, which is used in Lower Virginia, is derived from

these beds of Chama the friable texture of the shell upon exposure to the air rendering tliis speoies of marl more easy of application to land, and more prompt m its amelioratiug effects. CrasmtellcB often form an extensive deposit, and the large Peetens occar in con- tinuous layers of considerable depth and extent. The different species of Areaj Artemu, Crepidula etc., present a similar arrange- ment. Even those shells which are of comparatively rare occur- rence are usually found in little groups. Thus, the hoeardia/ratema is found to the extent of a dozen or twenty, closely packed together. This gregarious assemblage of shells of the same species is what would naturally be anticipated in the absence of violent agencies during or after their deposition, and furnishes another very striking proof of the comparatively tranquil condition of the sea or estuary in which they were allowed to accumulate.

Disposition of toe Fossils.

In nearly all the vertical sections of the deposit we ore now describing, a series of beds or strata may be observed, each dis- tinguished by the predominance of one or more species, and the order of superposition of these beds frequently continues without interruption for some distance. It does not appear, however, that in localities remote from each other, the arrangement of the shells is always alike, although in many instances there appears to be a striking correspou deuce. Id a majority of cases in the neighbor- hood of Williamsburg, the upper layer is composed principally of Chama eongregata. In many looidities also, the large Peeteiu, mingled with Ostrea VirginieOy occupy the highest place. But generally, the same shell reappears as a predominant constituent of one or more of the subjacent beds ; and such is the diversity of arrangement, even in places but a few miles distant, that it is obvious that no general order of succession exists. Thus, in a range of three miles we find Pema maxillata in some localities in the lowest stratum of dark blue argillaceous sand ; in others, form- ing an upper, or even the highest layer of the series. At Waller's Hill, three miles from Williamsburg, this fossil overlies the other shells, whereas at the College Mill, as already stated, it forms a part of the lowest visible stratum.

With the view of conveying more precise ideas of the disposition of the fossils in this region, we annex the following details in rela- tion to some of the more important localities which. have been minutely examined.

King's Mill, one of the most interesting fossil localities in the neighborhood of Williamsburg, is situated on the north bank of James river, about twenty-five miles from its mouth. The cliff in which the shells appear is abrupt, and has a height varying from twenty to forty-five feet above the water. The strata of ehells ex- tend along the river with slight interruptions, when the cliff sinks nearly to the level of the water, for a distance of between two and three miles, and they are found in a somewhat similar order of

saperposition for some distance inland. Their general direction is iiorizontal, bat the outline of any one stratum is frequently very irregular, the surface rising and falling with a steep inclination. This irregular outline is particularly remarkable with the beds of Chama, which are very thick at some points, and then fine oat rapidly and again expand.

This deposit of shells is covered to the depth of from four to six feet by a brownish yellow sand, intermixed with stripes of clay. Beneath this is a thin layer of about one foot of very argiUaceous and ferruginous clay of a red color. This rests upon a few inches thickness of gravel, consisting of water-worn quartz, rarely larger than a pea. Beneath this is a layer, from one to two feet thick, consisting of yellow sand, containing a great deal of the green or chloritic sand, arranged in narrow stripes. Next follows a layer of the same sand, containing principaUy Chama and Venus dtformis. This is from two to three feet in thickness. Immediately below is a stratum consisting almost exclusively of Chama, with a few Atra centenaria, etc. This stratum, varying from three to four feet in thickness, is a mass of compacted shells, with but little earthy mat- ter intervening. The earthy matter contains a very large proportion of the chloritic sand. The next stratuu) is composed chieny of large Pectens, and has a thickness of from one to two feet. Below this is another dense stratum of Chamu, together with Area cenUnaria, Panopea refiexa etc., and also very rich in the green sand — thick- ness, from four to six feet. Then follows a second layer, containing Pectens with Ostrea eompressirostra, one foot in thickness. A third stratum, in which Chama predominates, follows next, in thickness from two to three feet, and at the base of the cliif is a layer con- taining Pectins, Ostrea eompressirostra, etc., from four to five feet in thickness.

Thus through a height of more than twenty-five feet in some places, the cliff consists principally of shells, of which there are a great many species, besides those mentioned as predominating in tlie several beds. On the extensive contiguous estates of Eings Mill and Littletown, these shells are largely used as a manure ; and for this purpose the first and second beds of Cham>a are preferred, on account of the immense amount of calcareous matter and the large proportion of green sand which they contain. Judging from the occasional appearance of bluish green clay on the line of the beach, and in some places immediately at the base of the cliff just de- scribed, it is highly probable that a continuous strntum of tiiis sub- stance lies beneath the other beds throughout the whole extent observed. A horizontal bed of yellowish clay extends for some distance along a lower portion of the cliff, in which there are no fossils ; running within a few feet of its upper edge, and beneath this bed and parallel to it, is a thin layer of the iron ore formerly described. At the foot of this cliff appears the underlying stratum of clay.

Desobiptiok of the Cliffs at Yobktown, on York Riyeb.

The elevation, abrupt form, and peculiar structure of the cliffa at this point, and for some distance both above and below, render it an interesting spot to the geologist. A dry and ample bcacb, un- interrupted by creeks or inlets for several miles, affords a ready access to the banks, while tbe rivers edge, strewed with fossils which have fallen from the cliff, exposes a considerable variety of interesting specimens. Immediately at York tbe river is only three eighths of a mile in width, but both above and below it expands to a breadth six or seven times as great.

At Wormley's creek, about two miles below the town, the cliff about to be described begins; but from this point down, to the ex- tremity of The Peninsula the banks ore uniformly flat and low. The cliff here consists at bottom of a bluish sandy clay, containing im- mense numbers of Turritella alttcotta Cytherea Sayana and many small Univalves, over which lies a layer of brownish yellow sand, with very few shells, and those chiefly Nucula limaiula and a fw other specie& To this succeeds a stratum composed almost entirely of Grepidula eostatay so closely packed together as to leave little space for sand or other earthy matter. The wh(tle is covered to a variable depth by a stratum of coarse sand of various strong tints, and evidently highly ferruginous. The elevation of the cliff increases, and the nature of its contents gradually changes in approaching York. The lower stratum disappears entirely after continuing for some- thing less than half a mile, previous to which, however, its fossil contento are changed, the layer of the Turritella being replaced by Grepidula closely packed together. Crepidula still runs on hori- zontally above, and the intermediate stratum is now densely filled with Feetens, Venu$ dormU, Ostrea and a great variety of small shells frequently connected together, so as to form hard masses of considerable size. Still higher up the river the deposit assumes the character of successive layers composed of comminuted shells, con- nected together so as to form a porous rock. These fragments are generally so small and so much rubbed and water-worn as to render it impossibler to ascertain the species of shells of which they once were portions. Many small shells, and occasionally large ones, par- ticularly Peetens are found mingled with the other constituents of the rocks ; and in some places thin layers of shells, such as Venu9 and Crepidula intervene between the adjacent strata. The height of this fragmentary rook amounts in some places to forty feet. In most places it has a highly ferruginons aspect, though this is not invariably the case. Frequently shells of considerable size, such as Lucina cmodanta, are seen coated with, or entirely changed into, crystalline carbonate of lime, firmly cemented in the mass. The texture of the rock is various, at some points admitting of being readily excavated by the pick and spade, so as to form caves which have been occasionally used by the inhabitants; in other places ex- hibiting a hard and semi-crystalline structure, and having the com- pactness of some forms of secondary limestone. The lower portion

of the cliff, having less cohesion than the rest, has been scooped oat by the action . of water so as to give it occasionally an ImpendlDg attitude.

Above the town the stratum of fragmentary rock becomes mnch thinner, being now reduced to about ten or twelve feet. A stratam of yellowish argillaceous clay, abounding in ArUmU acetabulum Madras and other large shells, lies immediately beneath the rock ; and lower still appears the stratum of bluish clay, filled with Nueula limatula several species of Fusus, and various other fossils.

A narrow layer of iron ore extends along the cliff, with occa- sional interruptions, at a small distance above the fossiliferous strata.

This fragmentary rock continues in a narrow band, with some interruptions, for about a mile and a half above York. Beyond this point it is met with chiefly in detached masses. Extensive beds of shells, similar to those which appear at York, come to view in the vicinity of Bellefield, and line the shore for a distance of abont three miles. These beds rest on the usual stratum of sandy clay, and are in some places, as already described, covered by a stratum of the same substance. At a still remoter point, about six miles above York, on Jones plantation, a porous rocky mass occurs, overlying the stra- tum of shells in a thin and interrupted layer. Though very similar in appearance to the fragmentary mass before described, and evi- dently at one time composed of portions of shells, it is almost devoid of any trace of carbonate of lime. It appears to consist of silex, slightly tinged with oxide of iron, approaching in its porous char- acter and harsh, gritty texture to the nature of the burr stone of France. Associated with this is a more compact rock, containing some carbonate of lime, with much silex, and exhibiting very per- fect casts and impressions of Pectene, Cardium, etc. Over these strata is the usual layer of ironstone, and the general aspect of the upper beds is somewhat ferruginous.

It is interesting to remark, that with some interruptions, a fracmentary de])osit, similar to that observed at York, extends to the lower extremity of The Peninsula. At Pocosin, a flat swampy country, which is often inundated by the tides, this deposit is uni- formly met with by digging a few feet below the surfate. Peetun- cuius, Pectens, Ostrea, as well as numerous small shells, occur min- gled witli it, as at York ; the fragments, however, are not cemented together, but form a loose friable mass. A rock, consisting of ce- mented fragments of shells, occurs also at various other points on the eastern portion of the [Miocene district; and a fragmentary deposit, like that above described, is found near the extremity of all the peiinsnlas formed by our great rivers.

A very interesting feature in the structure of the cliff at York remains to be described. Though the general direction of the fossil beds is nearly horizontal, several of the strata of rock are composed of transverse layers parallel to each other, generally dipping toward the north, and making an angle of fifteen or twenty degrees with the horizon. The course of these lamina) sometimes differs in adjoining strata, and in some places the obliquity diminishes gradu-

ally on til the laminiB become horizontal; tbu presenting a remark- able rmblance to the appearances described by Lyell and others, as existing ia the Crag of England. The phenomenon here described, viewed in connection with the fragmentary structure of the rock, and the general distribution of broken shells over the lower extrem- ity of The Peninsala, would seem to indicate the former agency in this district of coast currents and an ocean surf. The beds of shelly matter comminuted by these means, and subsequently elevated above the level of the tide, would be gradually cemented into a rocky mass by the crystallization between the particles of such portions of the calcareous matter as the raiD, when just fallen, was capable of dissolving. The solvent power of rain, being chiefly due to a portion of carbonic acid with which it becomes united in its descent through the air, would be lost, as the liquid percolated through tlie shelly strata, and thus the calcareous matter which it had seized would be gradually deposited in the crystalline form.

Besides shells and zodphytes, the bones of cetaceous animals and the teeth of sharks are of very frequent occurrence in the fossil- iferous beds, but no remains of fresh water or land animals have as yet been discovered. The total number of si)ecies of shells from these points which have yet been identified is about ninety-six, to which may now be added several new species recently discovered, and described in a joint paper by Professor II. D. Rogers and my- self.

The structure of the interesting portion of the state lying on the eastern side of the Chesapeake is, so far as hitherto explored, extremely simple; but as yet only the surface strata have been examined, and it is far from being improbable, that at no very con- siderable depth beyond that reached by the ordinary wells of the country, depa<<its calculated to prove of much economical value might be attained. Beneath the superficial sands and sandy clays of the country, a bed of clay of a tenacious character is first reached, frequently impregnated with salt, and communicating to the water obtained from it more or less of a brackish flavor. Beneath this a more arenaceous bed occurs, beyond which, as far as 1 can learn, no digging has been carried. From this more sandy stratum, water of a purer quality is procured. Hitherto no beds of marl or fossil shells have been found any where in this region. Yet there is reason for the opinion, that such deposits would be met with by boring to some depth, and possibly near enougli to the surface to prove avail- able in the agriculture of the country.

The water of the Miocene marl district, whether of wells or springs, presents nearly as great variety as the mineral beds from which it issues. In the more eastern parts of the rejfionj it gener- ally contains a notable impregnation of common salt, and in neigh- borhoods where shell marl abounds, a marked proportion of calcare- ous matter. The copiousness and trafisparency of springs of the latter description, as well as the carbonate of lime which they hold dissolved, give them a character nearly allied to that of the lime- stone springs of other regions, while the common salt which they

almost invariably contain, nnd with which they are sometimes strongly imbued, constitntes an important feature of distinction. The beds of ferruginous clay and sand in many cases, impress a slight chalybeate character upon the water, and occasionally impart; to it so large an impregnation of iron as to render it of decidedly medicinal utility.

Owing to the calcareous matter, and occasionally other substances which it holds in solution, nearly all the water of this regicm pos- sesses the character of hardTieM. By boiling this evil is entirely remedied ;— the carbonate of lime is precipitated, first rendering the liquid cloudy, and subsequently collecting on the sides and bottom of the vessel in the form of a thin incrustation. In such of the arts as require a water free from this peculiarity, the marl water should be boiled previous to use ; or, in lieu of this, though by no means an effectual substitute, it should be exposed for some time to the sun in open reservoirs. The carbonic acid which is the chief solvent of the calcareous matter, being expelled by heat, suffers the latter to separate from the liquid, and thus the cause of the hardness of the water is in a great degree removed. It is obvious from these facta, that the water obtained from strata of gravel, sand, or pure clay will in general be jjurest and most suitable for employment in the arts. As an example of the kind of impregnation usual in the water of this district, I subjoin the results of an analysis of the contents of a spring in James City county, near Willian sbnrg. In 400 cubic inches of this water the aggregate of solid matter was found to be 104.49 grains, consisting of the following substances, viz. :

Muriate of soda 49.84

Muriate of lime 15.08

Carbonate of lim(5 26.78

Sulphate of lime 6.24

Silica nnd alumina 4.00

Sulphate of soda 0.26

Ammonia a trace

Organic matter 1.00

Loss 1.75

] 04.89

The large proportion of Muriate of soda shown to be present in the above instance is an interesting fact, particularly when taken in connection with the locality whence the water was procured. For it cannot be considered probable that this ingredient could be de- rived from the neighboring rivers or bay, as this would imply an extent of filtration in a horizontal and upward direction wluch it would be unphilosophical to admit. It is rather, as I conceive, to be looked upon as referable to the former impregnation of saline matter derived from the waters of the ocean, beneath which nearly all the strata of this region were originally deposited.

Natitbe and Yajuieties of the Miogbnb Shell Mabl.

In the general description of the district of which we are now treating, a detailed account has heen given of the arranement of the heds of fossils as they occur in nearly all the localities which have been examined, accompanied by an enumeration of the princi- pal shells, an account of the materiis in which they are embedded, and with which they are associated in contiguous strata. We are next to consider the materials of these beds in relation to their agricultural importance, and to exhibit the relative value of the marl of different localities as illustrated by chemical examination. A large proportion of the matter of all shells consists of carbonate of lime ; hence they are nearly identical in composition with lime- stone, chalk, and marble. To this ingredient, in whatever form it may be applied to the soil, general experience has ascribed a very high degree of fertilizing power, and hence, in the application of all the varieties of calcareous marl, we are guided chiefly by the propor- tion of the carbonate which they contain, as determined by chemi- cal analysis. It should not, however, be inferred, that the various mixtures of earths and other substances with which the calcareous matter is usually associated, are devoid of useful action when applied to land. The experience of agriculturists is certainly inconsistent with such an opinion, though it has most clearly evinced the power- ful efficacy of calcareous manures. The invaluable publications of the editor of the " Farmers' Register," by directing the attention of the farmers to the employment of the shell marl with which nature has supplied them in snch rich abundance, have led so extensively to the application of this manure, and have produced so general a conviction of its fertilizing effects, as to render it unnecessary in tins place to introduce either facts or arguments in its favor. To the valuable practical suggestions of this gentleman, contained in the Calcareous Manures" and other publicaons, we are indebted for much of the amelioration which has taken place in the agricultnre of Eastern Virginia, and I therefore cannot do better, in alluding to this branch of my subject, than to recommend these works to the earnest perusal of all who are interested in advancing the pros- perity of that portion of the state.

But, although the richness of the marl is mainly dependent on the proportion of its calcareous contents, it is also largely influenced by the nature and condition of the shells of which it is composed. It is well known that the recent oyster shell, especially in its un- broken state, is far less immediate and powerful in its action upon land than the friable and pulverulent shells, of which many of the most valuable marl beds are principally made up. Yet in the com- position of the recent oyster shell, the amount of calcareous ingre- dient IB nearly as great as in the richest marl beds which we have examined. According to an analysis which I made some years ago, 100 grains of this material were found to contain :

Carbonate of lirae 95.18 grains.

Phosphate of lime 1.88 "

Silex (probably accidental) 0.40 "

Water 1.62 "

Insoluble animal matter 0.46

Loss, etc 0.47 "

Total 100.00

((

Vids " Farmers' Register," vol. i, and Silliman's Journal."

These remarks being also applicable to some species of fossil shells, it becomes necessary, to a judicious selection of the marl, to give some attention to the different nature of the shells contained in the several varieties of marls offered to our choice.

Kinds of Shells wiiion abe least likely to be useful.

The fossil oyster and scallop shells (Ostrea Virginica andPeeten\ of wliich many marl beds are almost exclusively composed, are gen- erally found in a nearly unaltered state. Comparing the composi- tion of these shells, as ascertained by my analysis, with that of the recent shells, the animal matter which, though small in quantity, seems to act powei'fully as a cement for the other material*, was found to have been retained in almost undiminished proportion; and thus these shells are scarcely better fitted for the soil than recent ones of the same species. It is to the animal matter retained by the fossil scallops that we are to ascribe the dark color they assume when burned for lime. Whatever might be the usefulness of this ingredient if mingled with the soil, it here operates to impair the value of the shell as calcareous manure by the insoluble character it imparts to the materials it holds together. Kext in tardiness of dis- integration, and in consequent inefficiency as a manure, may be enu- merated the large clam ( Ventis mercenaria\ and an oblong, smooth, flat shell ( Crasaatella), These, however, have evidently undergone a change, which prepares them for yielding, more readily than the former, to the agencies of the seasons. Most of the other species, though entire when first found, soon fall to pieces and spread their fertilizing fragments through the soil. There is, however, even among them some room for choice — and this leads us to consider the

KfNDs OF Shells which are most suited fob the Pubpobb of

Mablino.

The Chama, formerly mentioned as occurring in extensive beds in some portions of the Miocene, and existing in considerable pro- portion in nearly all the fossil strata, fonuR the principal component of some of the most productive marls. This is a Small, two-valved shell, of rugged exterior, which readily breaks to pieces in the ground, and is spread evenly over the land with great facility. An- other shell {Serpula\ of which there are nnmerons rich beds in Surry county, possesses these advantages in a still higher degree.

is

From its fragile textare, and irregular tabular structure, it is qnioklj' miugled with the soil in a minutely subdivided state, and as like the Chamoy it frequently occupies the marl beds to the exclusion of other fossils, it furnishes a marl of a very superior description. As a general rale, the small shells are most likely to prove efficacious, as well from the fact that, where they occur, the proportion of car- bonate of lime and green sand is unusually great, as because thej are most easily reduced to the condition in which they become available in the land.

Of the Pulverulent White Marl. — In many situations the mnrl presents an appearance not very unlike that of an impure chalk. The mass of tlie stratum is chiefly made up of a white or yellowish friable material, intermixed with fragments of the harder species of shells.. In such cases the shells are rarely found entire, and the condition of the fragments is usually such as to render it difficult to recognize the species of fossil to which they belonged. Many extensive beds of marl of this description have been opened in the counties of Mid- dlesex, New Kent, James City, York, and Gloucester, all of them largely abounding in calcareous matter. Even as much as niuety- seven per cent of this substance was found in a s[)ecimen from one of these localities ; and it will appear from the table of cilcareous marls* hereafter to be given, that in general the proportion exceeds eighty in the one hundred. Occasionally, however, a mixture occurs in which the calcareous matter is blended with a large proportion of white clay and sand, presenting in the mass an aspect so nearly re- sembling the former, that wi&out chemical analysis it would be difficult to distinguish between them.

Qf the Blue Marl. — In our general description of the arrange- ment of the fossiliferous strata, mention has been made of the bluish green or clayey marl which ooours low down in the ravines and near the waters edge on the river banks. This is what is usually known among farmers as the blue marl. From the soft condition of the shelly matter which it contains, and the predominance of clay in its composition, this has been found peculiarly serviceable when applied to the more arenaceous varieties of soil. In the quantity of calcare- ous matter which it contains, it is usually inferior to the beds of a white or brown color, which in many places rest above it, though it is not to be inferred that in many instances it may not prove equally advantageous to the land. The coloring matter of the clay appears in part to consist of a carbonaceous matter, derived probably from the organic materials originally associated with the shells, and often in part of a minutely divided green sand, either of which in- gredients might be expected to aid the calcareous and clayey matter in benefiting the soil.

0/ the Bard Ferruginous Marls. — In some localities the beds con- sist of shells more or less broken, intermixed with a brown ferrugi- nous sandy clay, and often cemented with these materials into masses which are broken with some difficulty. These, although rich in calcareous matter, must obviously, from their mechanical texture, prove less valuable than either of the former. To this class also may

be referred the shell rock, and frannentary masses approaching to limestone, which occar in various places.

From the large percentage of carbonate of lime which these con- tfun, there can be no doubt that bj burning, they might be converted into A highly valuable lime. A specimen from the cliff at York yielded 87 per cent of calcareous carbonate, as large a proportion as most of the vnlley limestones have been found to contain : comput- ing the quantity of caustic lime, corresponding to this, we find that 100 ponnds of the shell rock would yield 48'7 poands of strong lime. It is therefore well worthy of consideration whether the conversior of this material into lime might not be an object of profitable en- terprise. In the neighborhood of York, and other places where it occurs, rock of sufiicient hardness might be obtained in great abund- ance, and at comparatively little cost; and the cheapness of fuel would render the operation of burning, one of moderate expense. That much of this rock, when exposed to intense heat, would fall to pieces, and thus injure the value of the product for distant use, is undoubtedly true. But there is also much of it found in bands throughout the cliff, which has almost as great solidity and penna- nency in the fire as a secondary limestone, and from this a lime of superior character might unquestionably be produced. Owing to the great abundance of shell marl in these places, and the general resemblance of this material to the constituents of a marl bank, its probable utility in this point of view appears hitherto to have been overlooked. But regarding it in its true light, as a tertiary lime- gtone, we see no reason why it should not become a source of profit- able manufacture in its immediate vicinity.

Of the Green Saxd, Sulphate of Tijox, and other Matters asso- ciated WITH the Marl Beds.

Gren Sand. — As already intiinate<l, this substance is frequently found disseminated in the marl, and also in the overlying stratum of clay or sand. From the remarkable effects of comparatively small quantities of this material when applied to land, there cnn be no doubt that many of the marls of Lower Virginia owe some of their value to its presence. Supposing only as much as ten per cent of this substance in a marl — and this is far below the amount which I have ascertained to exist in many localities— one hundred loads of marl would correspond to ten of the green sand, an amount which in New Jersey has often been found productive of striking benefit. Several of the most efiioient marls which I have examined were more remarkable for the large proportion of this substance contained in them than for their richness in calcareous matter. In many marl pits which I have visited, the impressions of the pick and spade were streaked with green marks, which upon inspection were found to result from the bruised granules of this matter. In such cases, there can be no doubt of the existence in the marl of an amount of green sand capable of affording material aid to the growing vegetable. In the layer immediately above the marl also, it sometimes exists in

considerablo qaantTty — and hence instead of rejecting this overlying mass, in many casies it woald be decidedly better to carry it out upon the land along with the calcareous matter. The experience of many farmers has already shown the propriety of this plan, and some even entertain the opinion that this upper layer, where the green sand abonnds, is quite as beneficial as the marl itself. Further observa- tions respecting the greensand will be given in treating of the Eocene marls', of which it constitutes a very important ingredient.

Sulphate of Iron and Sulphur. — In some parts of the Miocene district, there occur beds of clay more or less sandy, and usually of a dark color, containing these substances in a minute but still appre- ciable quantity. Such matter, there is reason to believe, would not in general prove beneficial to the soil. The former has been thought positively detrimental to vegetation, and certainly when applied in considerable quantity, this is its effect. What agency it might exert in a more diluted state, and mingled with other matter, we are without the means of determining. Probably under such circutn- stances it might operate as a stimulant, and thus contribute to the growth. The same doubts are also applicable to the other substance above named. Yet in some well authenticated cases the action of these copperas and sulphur clays has been found strikingly beneficial. In these instances, however, it would seem that much, if not all the benefit, was produced by the effectual protection which even minute quantities of these substances, especially the latter, afford against the attacks of insects. In a cotton field in which all the alternate rows were lightly sprinkled with earth of this description, the plants so treated grew up vigorous and healthy, while the others became sickly and were nearly devoured by insects. Much careful obser- vation is required to determine the kind and mode of influence which these substances exert, and it would be premature, in our present ignorance of the matter, to assert any convictions on the subject. The presence of the former of these ingredients, if not recognized by the copperas flavor, will be readily discovered by steeping the earth in water, decanting the clear liquid, boiling it down to a small volume, and then adding tincture of galls or prus- siate of potash. A black or brown color with the former, or a blue one with the latter, would indicate its presence. The experi- ment, however, should be made in a glass or china vessel. The sulphur becomes manifest to the smell when the clay is heated, and even at ordinary temperatures its peculiar odor may often be per- ceived.

The following table exhibits the percentage of carbonate of lime in a number of the Miocene marls which I have examined. The analyses were made with the apparatus for analyzing cal- careous marls and other carbonates," described in the " Farmers' Register" and "Journal of Science." No attempt was jnade to ascertjun the proportions of sand, clay, or green sand, because the trouble of the analysis would have been increased more than ten- fold, and probably no useful result could have been attained. In

each experiment the appearanoe and character of the nndissolved matter were noted, and thas a general estimate formed of the other ingredients of the specimen. These notes are contained in the foarth column, the first giving the localities, the second the aspect, and the third the quantity of calcareous matter :

Table EzniBiTisro the Pes Geitt. of Oabbonatb of Limk nr

MiooEKB Mabls.

Gloucester. Walter Jones ,

Walter Jones

T. W. Fftuntleroy

Several feet below surface

From same bed near

surface

Dr. Taliaferro, from gray

low CTOunds

BInck Tow grounds. . . Highlands, upper

stratum

Highlands, lower

level

Isle of "Wight. Burwell's Bay

BurwelPs Bay.

Joel HoUcman

Jakes Cftt. The Grove—BurwelPs. . .

From a lower stratum

King's Mill diff,

Judfre Semple's farm, two miles below Williams- burg

White sandy marl, with fragments of Bsrna

White clayey marl . .

White pulverulent..

Fine chalkv — few traces of shells

More arenaceous. . . .

Blue marl... Yellow marl.

White, with small shells

Seddish (pmy witli fragments of shells and numc oiis specks of green sand

Similar appearance, specks more nu- merous

Similar aspect

The residuary matter chiefly silez. No

jBrreen sand.

The residuary matter chiefly clay, with a little green sand.

Chiefly clay, no green sand.

No green sand. Sand.

A little green sand.

A little green sand — chiefly clay.

Sand, clay, and a con- siderable projwrtion of peroxide of iron.

A little green sand.

Sand, clay, and larppe proportion of green sand.

Sand, clay, and still more wcemn sand.

Sand, clay, and much green sand.

Gix>ucESTKB — {eantintud)

Dickie Galt'8, near Will- iamsbaTg hospital

Dr. Semple'R, 18 miles fh>in WilliamsbuTg

Another stratum

Dr. Peachy's, near James- town

Mr. Wynn's, near York. .

Mr. Wade's

Lancabteb. Cuxratoman — J. Cabell, Esq., first bed

Second bed Third bed.. Fonrtiibed Fifth bed..

MiDDLEflaez. Mr. Jesses, near Urban-

na. No. 1

No. 2

Dr. K. Christian, near Urbanna

Mrs. Thurston's, 8 miles from Urbanna

Nbw KEirr. Mr. B. Crump, 6 miles below CouTt-Houso. . . .

Mr. Bo. Christian' s

Mr. J. MarshalL

PitnroB Geoiioe. Mr. William Harrison . . .

Suhey.

Mr. C. Jones

Lower stratum,

Upper stratum

Capt. Smith, Court-House

Pulverulent and white

Yellowish pulveru- lent ...

Grayish yellow

White pulverulent. White pulverulent.

White pulverulent .

Grayish yellow si- licious clay, filled with hollow castcf of Astarte undulata,

Fracnts of shells,

but no oasts

Fragments of shells,

but no casts

Fragments of shells

but no casts

Fragments of shells,

but no casts

White pulverulent. .

Sandy and grreenish

blue

Chalky — small frag- ments of shells

White and pulveru- lent

White pulverulent. White pulverulent. White pulverulent.

White pulverulent.

Grayish

Grayish yellow

Abounding in (7Aa47ui 62.7

Bank made up of ChamataiiiSfrpula 72.9

No green sand.

Sand and clay. Sand and clay, and some green sand.

Chiefly clay.

Clay and a little green

sand. Clay and a little green

sand.

Clay, sand, and ozidcof iron. No green sand.

Clay.

Cky.

Clay.

Chiefly clay.

Much green sand.

Sand and clay.

Sand and clay, and

much green sand. Sand, clay, oxide of

iron, and much

green sand. Sand and much green

sand.

Much rcen sand.

SuRRT — (continued,) Baooii'k Cftstle

White pulverulent. .

White sand, with

fragment? of At/mi. Very aiilluocouB...

White pulverulent. .

Seddih yellow — fruentH of shells.

Bocky and sub-crys- talline

No een sand.

Mr. D. Stith, Court- H0US6

Union Hall

85.0 Snnd. No irecn sand. 211.8 No ifreen sand.

York. Mr. R. Garrett's, 8 miles below York

Belle farm — Major T. Griffin

York cliff

79.2 1 Clay and oxide of iron.

87.8 i ninv and oxide of iron.

EooENE Mabl Distbict.

As already indicated, the extent and bonnduries of this inter- esting poilion of Eastern Virginia are as yet in a great degree mat- ters of coiecture. The disoovery of an Eocene deposit in the state, first announced by me about eighteen months ago, in a com- munication to the Farmers' Register,' has been followed up by a n)inQte personal examination of some parts of the district in which it occurs, more especially on the James river and Pamunkey. Its existence on the Kappahannock and Potomac has also been ascer- tained, and specimens have been obtained from a number of inter- mediate points. With regard to the region south of the James river, though facts have been procured which show conclusively that the deposit continues to the southern boundaries of the state, time has not admitted of such an investigation as would be neoessary in defining its extent. A regularly continuing line of observations on the Pamunkey river, commencing below the point at which the deposit appears above the waters edge, and extending up the river to the junction of the North and South Anna, where it terminates, has served to develop the arrangement and composition of the strata, and to determine the width of this portion of the formation. An inspection of the most important Eocene localities on the James river has also contributed many interesting and valuable facts, while on the Kappahannock and Potomac, its western limita have been determined with as much accuracy as could be attained bj transient observations directed only to a few localities.

Wherever observed, the arrangement of the beds of the Eocene, and the minerals and fossils contained in them, have been found strikingly alike, and hence the description of any transverse line of the formation may be regarded as conveying a just representation of its character throughout. At the same time, however, it is by no means to be assumed, that in all localities the same arrangement or composition of the strata roust necessarily exist; for within a short disUmce in observations already made, considerable diversities have been observed to exist. But there can be little doubt that the

general order of the Btrata already remarked, as weU as the char- acter of the fossils which thejr contain, wiU present much uniformity whenever the formation may be discovered witiiin the limits of the state.

The existence of Miocene strata over the Eocene has been re- ferred to nnder a former head, and some account of this more recent overlying deposit within the district of which we now are treating, may, with propriety, be prefixed to the description of the Eocene itself.

Of TBS Miocene which ovxbubs the Eocene.

Westward of the limits of the Miocene previously defined, the general level of the country continues gradually to rise. A surface more generally undulating, and strewed with water-worn fragments of stone, sometimes of considerable size, marks our approach to the region of hills and rocks, whence these memorials of the destructive forces of a former period have been derived. The superficial stratum. in the western portion of this district is generally a coarse sand or gravel, often containing large masses of rounded sandstone and other rooks, of which the parent strata are generally to be found at no remote distance to tne northwest. An inspection of these pebbles is safilcient to show, that in many, if not nearly all cases, they are derived from the grits and sandstones with which the bituminous coal of Eastern Virginia is Associated, while from the similar nature of the sand and gravel in which they are embedded, we are entitled to conclude, that at least in part, they also refer themselves to the same region for their origin. In the hills at and below Richmond, and in many other places, these beds of (pave! have considerable depth, and present a structure at once cnnous and instructive. A series of strata at these places, in some of which the pebbles are dis- posed in horizontal lines, in others in lines oblique, but still gener- ally parallel, inclining downwards to various points in the different layers, give striking evidence of the agency of those diluvial and oceanic currents, of which geologists have discovered so many me- morials in other regions, and may serve when minutely studied, to throw much light on the physical changes to which this portion of the continent must formerly have been subjected.

Beneath these beds of gravel, in many places strata of clay occur ; but whether referable to the same epoch of deposition, cannot as yet be clearly ascertained. Many beds of argillaceous clay, suited for the potter and brickmaker, and occasional layers of a beautiful yellow ochre, may be placed in this portion of the series.

Other strata of clay and sand of a peculiar character present themselves in many localities beneath the superficial beds. These contain a record of their origin, legible to the geologist, in the im- pressions of shells and zoophytes with which they are generally filled. On comparing these casts, which in most cases can be easily recognized even in their more delicate markings, with the fossils of our Miocene marl strata, their identity is established, nd thus the strata in question at once take their places in the series of Miocene Tertiary deposits.

In muiy parts of HanoTer, King William, Henrioo, and other coanties in this range, these heds of clay are found, nsoally charao- terized hy a dark greenish grey or brown color, a snlphnroos odor, and an astringent taste. On Governor's Hill in Richmond, a stratum of the same kind is exposed ; and at this spot tlie fossil impressions and other characters above noticed may be distinctly seen. Like the clays and sands formerly described as associated with the Miooene, these contain salphate of iron (or copperas), sulphate of alnmina and sulphur in an uncombined condition. So large a proportion of these substances is sometimes present, as to render the water obtained from the strata in which they exist, absolutely unfit for use.

It is to the existence of these materials in the strata that we are to look for the cause of the disappearance of the calcareous matter, in the form of shells, which they once evidently contained. Either of the sulphates above named would exert a rapidly decomposing action on the carbonate of lime, of which shells principally consist ; tlie sulphuric acid of the sulphate combining with the lime of the carbonate, thus converting it into gypsum, while the carbonic acid would, in great part, escape in the form of gas. That the gypsum is not now discovered in these beds is an obvious result of the com- parative solubility of that substance in water ; its continuance in the strata being only possible where a heavy covering of clay excluded the percolating liquid.

Useless, if not iijurious, as these clays are now believed to be when applied to land, there is reason to think that they are capable, by a little application of chemical knowledge, of being rendered truly valuable as an auxihary manure. The gypsum into which their en- closed shells were once converted, would doubtless have imparted to them high agricultural value. Can we not replace, if not all. some portion of this fertilizing material, by minglmg the clay with the more pulverulent shell marls occasionally found in its vicinity ? That this mixture would result in the conversion of a portion of the shelly matter into gypsum, there can be no doubt ; and where the clay was originally rich in copperas and sulphate of alumina, the amount of the gypsum thus compounded would be proportionally great Ex- periments on this subject are well worthy of being tric, not only with the clays here mentioned, but with those of a similar nature, which, as already remarked, occur in the more eastern portion of the Tertiary districts of the State.

Before the amount/ gypsum to be anticipated from such a treat- ment of these materials can be estimated, a chemical determination of the proportion of sulphates of iron and alumina must be had, and to this point future analysis might be usefully directed.

But though much of the Miocene marl in this district has been exposed to the destructive chemical agencies above explained, much also is found retaining its carbonate of lime in undiminished quantity.

On the lower levels on the river banks it appears seldoip to have escaped the dissolving and decomposing action of the sulphates, while in the highlands it may usually be found containing its cal-

oareons matter early as when first deposited. In King William, Han- over PHnoe Greorge, etc. beds are found in the highlands, at some distance from the rivers. The fossils they contain are identical with those of the marl beds farther east, and the materials with which they are intermixed present no peculiarity important to be remarked. Specimens of this Miocene from Hanover, King William, and Prince George, exhibit a good percentage of the carbonate of lime, and as might he expected, the strata from which they were taken are nse- folly resorted to by the neighboring farmers.

As would be inferred from remarks previonsly made, the general level at which this marl occors, is higher than that of the Eocene, and here the promise is held ont that this latter, even in the high- lands, would he exposed by excavations carried to some depth be- neath the lower limits of the former.

In examining the Eocene deposit on the Pamnnkey and James rivers, the interesting geological fact was observed of an actual wperpaHtion of the Miocene upon it ; and on the Pamnnkey, the precise point was determined at which the Eocene first makes its ap- pearaaoe ahove the water-line, heing there overlaid by a heavy bed of the more recent deposit. This occurs at North bury, and directly opposite at the plantation of Dr. Charles Braxtun.

Of tbe Eooeke ob Lower Teutiaby Mabl.

Tlie descriptions and facts which will be comprised under this head, will principally refer to the localities on the Pamnnkey and James rivers, to which especial observation has been directed ; at the same time that their value, as appljdng to the Eocene district generally, may he regarded as being sufficiently established by gen- eral geological analogies, as well as such observations upon other portions of the region, as the presentearly stage of the enquiries has allowed me an opportunity of making. No region of Eastern Vir- ginia holds ont more certain promise of reward to future investiga- tion, and none will reap from the research more lasting and impor- tant benefits.

DBSCBIPn0)7 OF THE EoOEXE StBATA OF THE PaMUKKET.

Rising above the water-line at Northbury, the upper surface of the deposit is seen ascending with a very gentie slope, as it extends higher np the river, nntil at Newcastle it attains an elevation of about twenty-five feet above inedinm tide. Beyond this point, with slight andolations in its ontiine, it continues, with but little general deviar tion of height from the water-line to near its termination at the junction of the North and South Anna, where it dips or thins out until lost immediately on the verge of the coarse sandstone, which there, for the first time, makes its appearance in massy form. The deposit appears on both sides of the river, wherever the fiats do not intervene, and at the base of the second level, corresponding in position to its place in the river cliffs in the same vicinity.

On the sooth side of the river, the deposit has heen particnlariy examined, at Northburj, Hampstead, Retreat, Washington Bassett's, Walker Tomlin's, Mrs. Rufiin's, Mr. Roane's, and Mr. Wickbam'a, where it terminates. Specimens have been collected from other localities, either on the river or at the base of the second level : on the north side, at Cheriooke, Oaptain Hill's, Mr. Nixon's, Piping Tree, Newcastle, Dr. Braxton's, and Mr. Fox's. Specimens aJso from various other points on and remote from the river, have been procured, and thus a somewhat minute acquaintance with this por- tion of the Eocene tract has been attained. Toward the southern boundary of the deposit, the following arrangement of strata occurs, commencing at the top :

1st A stratum of greenish yellow earth containing no shells, but numerous traces or casts of them, plainly showing that shells were at one time embedded in the mass. Sulphate of lime or gypsum occurs in crystals, sometimes of considerable size, interspersed throughout this stratum, which is principally made up of coarse silicious sand, blended with granules of green sand or silicate of iron. The thickness of this bed is variable: at Chericoke and Hampstead it is about two feet ; at Retreat, from four to five.

2d. Beneath this lies a layer of dark, greenirii blue or brown earth, which when dried, generally falls to pieces, and is discov- ered to consist mainly of coarse siliceous sand and green sand, to- gether with shells generally in a broken condition. The shelly matter is sometimes entirely wanting, though occasionally it com- poses a large portion of the mass. At Hampstead the calcareous ingredient exists in large proportion and in a finely diyided state. Freauently, one or more thin layers of the oyster shell peculiar to the Lower Tertiary region occurs in the body of this stratum ; a fact remarkably exemplified at Piping Tree, and for nearly a mile farther down the river, where the layer of shells forms a hard rocky self laid bare at low tide, and presenting large and perfect specimens of the fossil oyster, in the midst of the greenish stratum just described.

At Chericoke the stratum rises to about four feet above the water, and as ascertained by digging, descends to seven feet below the river shore.

Higher up the stream these strata attain a greater elevation, and subjacent beds not apparent at either of the points above described, come gradually into view. In these localities we usually find —

Ist. A layer of dark greyish green or greyish brown colour,con- taining multitudes of shells, generally in a perfect state ; the fossil oyster shell already referred to abounding chiefly in the upper part of the stratum. Beneath this, but frequently separated by no dis- tinct line of demarkation, we find —

2d. A layer of darker hue, containing less shelly matter, and the shells chiefiy of the smaller kinds ; and —

8d. A stratum of the same appearance, in which no calcareous matter can be discovered.

All these strata contain a large portion of the green sand. In the upper afid lighter coloured bs, the granules of this substance

are very obvions to inspection, resembling in size and colour the grains of ganpowder, and giving when bruised a bright green stain. In the lower beds they are more minute, and being intimately mingled with the other materials present, are not readily recog- nized, excepting by the general greenish character of the mass. These beds also contain a great deal of mica in fine, sparkling scales. Of the depth of these strata below the level of the river nothing definite is known, no extensive excavations having yet been made. At Mr. Wickhams they are found to rest upon a layer of large peb- bles, but this basis is perhaps not co-extensive with the deposit lower down the river.

When the upper bounding surface of the Eocene is even and uniform. It is always marked by a thin layer of hlfteh pebble* upon which there usuallj rests a bed of olive coloured earth, or of friable white clay — and in some cases, both these strata, the olive coloured being next the Eocene.

This olive earth is of a fine texture, contaming but little gritty sand. Here and there a sharks tooth in a decomposed condition, or the impression of a shell, may be discerned. The white stratum abounds in casta, but never presents the shells themselves. It shows a light trace of gypsum, but in neither of these beds does there exist any carbonate of lime. From the character of the organic impres- sions they contain, they dearly refer themselves to the Miocene formation.

In some places on the river, particularly where the upper bed of the Eocene contains gypsum, as at a point a little below Piping Tree, a thin layer of ferruginous rock abounding in casts, occurs immediately in contact with the Eocene ; this also is to be placed among the strata of the Miocene.

A more distinct conception of the order and extent of the strata of both the tertiary divisions, as they occur at difiTerent points along the river, will be obtained from the following summaries derived from observation.

On the north bank of the river, in a cliff about half a mile below Piping Tree, the beds taken in a descending order are —

Miocene, — 1. White, friable, sandy clay, containing fos- sil impressions 10 ft.

2. White, sandy marl, with broken shells. . . 8. Ferruginous stratum, abounding in cants, and occasionally containing the shells

themselves "

4. Thin band of black pebbles.

Eocene, — 6. Dark green sand stratum, no shells 4

6. Rocky shelf of cemented shells of the

saddle-shaped oyster .

7. Dark green sand stratum, with small shells. "

m

The highest Miocene bed is not exposed at this point, but occurs

a little farther up the riyer in the character of a dark hlne clay witii fossil impressions, on which there rests a thin layer of ochreona clay, as oriUiant in its tints as the finest chrome yellow. This ociire is of the most impalpahle teztnre when dried, and would be found very valuable in colouring.

At Mr. Washington Bassett's, about four and a half miles higher up the river, the bank is precipitous, and presents the following series of strata :

Miocene, — Superficial gravel 5 or 6 ft

Thin layer of friable sandy clay with

Olive colored earth, with sharks' teeth

and a few casts of Miocene sheUs. ... 7

Thin line of black pebbles.

Eocene. — Dark greenish brown stratum contain- ing a large proportion of green sand, and in some parts abounding in shells. The upper portion consists of a rocky mass of cemented shell, chiefly the sad- dle-oyster 20

At Walker Tomlin's, on the south side of the river, immediately below Newcastle, the beds are —

Miocene,— Yn&hle white clay and sand with casts of

shells 2 ft

Eocene, — Olive earth with pebbles at bottom 6

A dark bluish green clay, containing a great deal of green sand, capped by rock as at the former locality 25

At Newcastle and William H. Roane's and Mrs. RufBu*s estates, a similar series of beds occurs, rising still higher above the level of the stream. About one mile and a half above Newcastle, the upper surface of the Eocene marl has an elevation above the river of more than thirty feet. The lower stratum consists of the bluish green clay before mentioned, containing only a few of the more delicate shells, and richly abounding in green sand ; the upper, of a grey calcareous marl, thickly speckled with granules of this substance. Over the whole is a layer of the white, friable material, with Mio- cene impressions.

The upper surface of the Eocene usually presents an unbroken line, thougn at some places, as at Mr. Fox's above Newcastle, this is not the case. The bed here consists of a light-coloured sand and clay speckled with the green sand, and containing vast numbers of the Eocene oyster. Its outline presents numerous cavities and eminences, exactly resembling those which occur in the Miocene deposit nearer to the seaboard. A narrow layer of common sand deeply tinged by mixture with green sand, lies immediately upon

this iiregQlar sarfaoei and the whole is covered with a bed of grayel and sand with diagonal lines of stratification, indicating the agencj of corrents at the time of its deposition.

At Mr. William Wiokham's the overlying stratum consists of bands of ferrnginous gravel and sand, oontaining roand concretions tike geodes, generally fiUed witb sand. Thin seams of iron ore ran along this stratnm a few feet above the fossiliferons beds. These latter in some places present a level ontline, and are then always covered hj a layer of sandy day containing mnch green sand. On the other hand, where the ontline is nndalating and irregnlar, a stratum of gravel rests immediately in contact with the bed of marl. The size of the gravel thas deposited, as well as the scooped sarfaoe of the bed on which it reposes, indicating the operation of powerfnl currents after the deposition of the strata of Eocene, presents an explanation of the absence in these places of the upper Ded of this formation, remarked as present in those spots where there are no such indications of the action of destructive forces. The matrix of the fossils is sometimes an olive-colored clay, some- times a greyish green sand and clay, and sometimes a bluish black clay, oontaining a large proportion of the granules of green sand. The depth of the marl is fifteen feet

EocvKE Stbata of trk James Rtveb.

The beds of Eocene on the James river first make their appear- ance on its southern shore near Ooggin's Point, and thence continne, except when interrupted by the river flats, to a small distance above City Point, making a distance, following the flexures of the shores, of about ten miles. On the opposite siae they have been found at Berkeley and other points, but as yet this portion of the deposit has been bat little examined.

At Ooggin's Point, Tarbay, and Evergreen, the cliffs have a height varying from thirty to forty feet. The Miocene marl, which in some places is seen overlying the Eocene, abounds in scallops and other sheik which make it easily recognized. Beneath this, and usuallj separated from it by a thin line of black pebbles, like those occur- ring on the Pamunkey, there occurs a stratum of a greenish red and yeUow aspect, oontaining mnch green sand and gypsum, the latter partlj disseminated in small grains, and partly grouped in large and massive crystals. The under stratum, rich in green sand and con- taining a few shells in a friable condition, extends to some depth beneath the level of the river, and appears to rest upon a bed of day of a lead color, containing crystals of gypsum. At Evergreen a stratum of pure white clay rests upon the upper layer of Eocene, containing, embedded in its lower surface, laige groups of crystals, and seems to occupy the place of the black pebbles before men- tioned. The whole thickness of the Eocene deposit at this point appears to be about twenty feet. Below as well as above this place, its height declines until no portion of it is any longer visible above the water*B edge.

EoozirB Deposit of the Potomac, Rappahaknock, and Matta-

Pont, Etc.

Although the shores of these rivers have fts yet been bnt little exatniDed with a view to the structare and arrangement of the vari- oas strata they exhibit, enough has been observed to prove that they are no less rich in the Eocene marl than the other districts which have been described. On Potomac creek, and for a great distance below its moath, the green sand strata may be seen running along the base of the cliff; and from specimens examined, there can be no doubt that the character of the deposit is similar to that of the Eocene of the James river and Pamunkey. On the Rappahan- nock, for a considerable distance below Port Royal, the very same appearance is presented ; and the green sand obtained from some of these localities is in every respect like that from the points already noticed. In some places on the Mattapony the occurrence of the green sand stratum has been ascertained, while in others the beds containing this substance are replaced by beds of clay, which, though geologicaUy of the same (or Eocene) formation, are yet lees likely to prove interesting to the agriculture of the vicinity. Minute enquiries throughout all this district, and throughout the corresponding region south of the James river, are alone capable of developing the extent and value of this deposit. Even a great deal yet remains to be done in investigating localities on the James and Pamunkey rivers, the northern shore of the latter being so far almost unexplored, and the precise character and value of some of the beds in localities exam- ined being but imperfectly ascertained.

Of the Several Beds composing the Eocene Formation.

In treating of the accompanying Miocene in the beginning of this section of the report, our descriptions have been confined chiefly to those beds which occur remote from the rivers upon the highlands, and no mention has been made either of the white, friable sand or olive colored clay, already frequently noticed in describing the overlying strata on the Pamunkey.

The first of these, though once the repository of shells and other fossils, is now entirely destitute of carbonate of lime. A smidl quantity of gypsum in a minutely divided state seems to be its only ingredient of any value, and the amount of this present in the speci- mens I have examined is much too inconsiderable to give the mate- rial any agricultural importance.

The otive earth, which is fre<juently an extensive layer, has also lost all the calcareous matter which it once contained ; but a further examination, chemical and geological, of this material, will be re- quired before its nature can be exactly determined, or the possible applications of which it may admit can be ascertained.

The upper bed of the Eocene, characterized in most of the locali- ties by the gypsum which it contains, is worthy of esped consid- eration on account of this valuable ingredient. In specimens from

6T

the James river, from five to eight per oent of this Bobstance has been found in a divided state, at the same time that a considerable additional qnantitj in a massive form exists in various parts of the same stitum.

On the Pamnnfcej this stratum is not so thick, and is perhaps less abundant in the sulphate of lime. The lower beds, in some oasea containing a marked proportion of shellj matter, and in others having almost none, are more especially distinguished bj the larger proportion of another and even more important ingredient, to wit, the green sand. Both on the James river and the Pamunkey their ricbnesa in this material gives them an agricultural value which per* hiqw no proportion of calcareous matter by itself however great, would be able to impart. The illustrations of its beneficial Bcts, and the general observations upon its employment as a manure or marl, which will hereafter be presented, will, I think, manifest the justice of this opinion, and give a sound confidence to those who are disposed to make trial of its powers.

Extent and Cohmodioub PosmoK of tab Eocene on the Bivess.

One of the most interesting facts presented in the foregoing de- scription of the Eocene on the Pamunkey and James rivers, is the great depth and extent of those strata, which, from the nature of their contents, may be applied to profitable ase in agriculture. Beds of such materials, preserring an average thickness of twenty feet, extend along the banks of the Pamunkey, with occasional Interrup- tiona, for more than twenty miles.

Their position on the river shore makes them of most convenient access, snd gives additional facilities to the conveyance of the fer- tilizing materials they furnish to various distant points, while fh>m the peculiar character of the strata themselves, they are almost exempt from the usual destructive agencies of the freshets, being of a texture to withstand with scarcely any loss the most violent as- saults of the sweeping currents by which the banks of the river are so often overfiowed. To this cause we are to ascribe the steep de- clivity of the shores in many narrow parts of the river, where the abrading action of the water, instead of rapidly carrying off the ma- terials of these strata; has merely served to wear them into smooth and almost perpendicular precipices rising immediately from the margin of the stream.

Existxnok of the Eocene beneath the Highlands, and

THBOUOHOUT THE WhOLE BbBADTH OF THE StATE.

The general position and direction of the Eocene beds suggest another view of great practical importance to this and the neigh- boring districts of the state. I allude to the probable, perhaps I may say certain, continuation of these strata over a wide area, on a level corresponding to the general depth at which they are found upon the rivers. In confirmation of this view it may be remarked

that since the pnblioation of a commnnioadon on this eablect in tbe Fanners' Register," the existence of a similar deposit throughout an extensive district of Maryland, Ijing in the general direction of onr Eocene formation, has been bronght to light, and there is reason for believing that within the borders of iforth Carolina, near to the Virginia line, the same strata are displayed in the banks of sev- eral of the streams. In the belief then that all this extensive band of country, stretching in a meridional direction entirely across the State, rests upon strata of this description, we are led to regard it as furnishing an immense addition to the resources of the State, and as holding out to our enterprising farmers ntuated within its limits, a new motive to persevering and active research. Let it not be supposed, however, tnat wherever the Eocene occurs within our state, it will be found to present the same materials in the com* position of its strata, as have been found in the localitiea already examined. Much diversity in this respect may, and probably does exist. On the Mattapony, as already stated, the green sand is fre- quently replaced by beds of clay of a dark lead color ; while on the Potomac, Bappahannock, Pamunkey, and James, variable but gen- erally large proportions of the green sand occur, and the probability is, that future enquiries will develop similar diversities in the ma- terials of the beds in other yet unexplored portions of the districts Constancy in the character of the embedded fossils is all that is necessary to a geological identity of the formations, and this con- stancy may exist at the same time that there is a considerable diver- sity in the materials in which they are enclosed. It is ahnost certain, however, that throughout a large portion of the region in question, extensive and valuable beds containing the green sand do exist, and that even in the highlands they might be reached by ex- cavations descending not very far beneath t£e lower limit of the Miocene or ordinary marl.

On thk Value of thb Eoosnb Grbbn Saitd Mabl in Aobioultukb.

From the descriptions already given of the materials of the va- rious beds of Eocene, it will be seen that many of them contain ingredients which have long been recognized as valuable when ap- plied to land. The gypsum in some, and the carbonate of lime m others, will at once bespeak the favor and confidence of tlie agriculturist, and no observations, either as to their usefulness or mode of application, will be necessary to give them the importance they deserve. But the eharaeUristie atkd principal ingredient of a large number of these beds, the areen Band, possesses claims to our attention which are equally indisputable, tbough not so generally appreciated or understood. Experiments within our own state on this material, as furnished by the Eocene deposits, though few, and on a very limited scale, have been so far satisfactory. But as the marls containing this substance, which have been employed, have also in most cases contained a notable quantity of gypsum, or of oalcareous matter, all the benefits which they have produced would

most nataraUy and reasonably be ascribed to those ingredients, already known for their agency in ameliorating the land. On the Pamnnkey the Eocene marl has long been in nse, bnt chiefly those beds have been selected for the purpose of marling in which the largest proportion of calcareous matter was seen to exist. The lower layers, containing little or no calcareous matter, have on that ao- ooont ontfl lately been rejected as useless, and sometimes when a bed of this description of considerable extent was found immediately overlying a more shelly stratum, much trouble and expense have been incorred in its removal, to make way for the excavation of the material beneath. Appealing to the experience of the farmers of New Jersey, by whom the green sand, in an almost unmixed con- dition, baa long been applied for the purposes of a manure, its un- rivalled efficacy, aud the permanency of its ameliorating effects, are to be regarded as established and unquestionable facts. It is true, that at one time, owing to the ignorance of those who attempted to make use of it and the application frequently of a spurious ma- terial resembling it in aspect, doubt of its value have been excited in the minds of some ; but the extensive and uniform experience of the present enterprising farmers of that state, gives an unqualified testimony to the rapidity, the power, and the durability with which it acta.

A comparatively small dressing of this marl, often not exceed- ing ten or fifteen loads per acre, is uniformly attended with benefi- cial results, and this whether the soil to which it is applied, be a day or a light sterile sand. As an illustration of this fertilizing property of the green sand, I will subjoin the following statement, quoted from the report of my brother, Professor Henry D. Rogers, on the geology of New Jersey, to which work I beg leave to refer for ample and satisfactory details relating to the agricultural value of this substance, as well as for practical suggestions as to the most jndicions modes in which it may be applied :

When we behold a luxuriant harvest gathered from fields where the soU originally was nothing but sand, and find it all due to the use of a mineral sparsely disseminated in the sandy beach of the ocean, we must look with exulting admiration upon the benefits upon vegetation conferred by a few scattered grannies of this unique and peculiar substance. The small amount of green sand dispersed through the oonmion sand, is able, as we behold, to effect immeasur- able benefits in spite of a great predominance of the other mate- rial, which we are taught to regard as by itsetf so generally preju- dicial to fertility. This ought to exhibit an encouraging picture to those districts not directly within the limits of the marl tract, where some of the strata possess the green substance in sensible propor- tion. It expands most materially the limits of the territory where marling may be introduced, and points to many beds as fertilizing, which otherwise would be deemed wholly inefficacious."

If such then be the effects of this material, even under circum- stances where comparatively little advantage could have been antici- pated, apQd if such moreover be the oonoorrent experience of those

bj whom it is dailj and eztensiyely employed, we are fblly aathor- ized in the belief, that in the £oGene beds of our own state, thoo in general less rich in the fertilizing ingredient than the Secondary strata of New Jersey, the agriculture of Eastern Virginia poasesses a new and most valuable resource.

The chemical examination of these marls, with a view to precise results, being a matter requiring much time and labor, has as yet been carried on only to a small extent Bat a thorough ttialysis of all the important varieties, and an exact determination of the propor- tion of the various constituents, especially the green sand, or the cflJcareous matter in different localities, will be a work from which much practical good may be derived. By the light of such reaolta alone, can the farmer be sately directed in applying it to the soil, or be properly guided in distinguishing between a material which is spurious and one which will be found salutary in its effects upon tne land.

The following results are to be looked upon as approximate terminations, but will serve to illustrate the composition of aevend varieties of the marl :

OoMPOBtnoN OF Gbebn Safd (Eocknk) Mabls.

Dr. Corbin Braxton's.

Silica and alumina, eta 60

Carbonate of lime 10

Green sand 88

Gypsum /. 2

Walker Tomlin's, lower stratum.

Silica and alumina. 60

Carbonate of lime and gy psnm a trace

Green sand 40

Conrad Webb's.

Silica and alnmina, etc. 80

Carbonate of lime. 46

Green sand 25

William H. Roape's, lower stratum.

Silica and alumina, etc 60

Carbonate of lime. 4

Green sand 43

Gypsum 3

Tarbay, lower stratum.

Silica and alumina, etc , 40

Cnrbonate of lime. 8

Green sand 67

do upper stratum. Gypseous earUi containing from 6 to 10 per cent of gypsnm, and from 10 to 16 per cent of green sand.

Berkeley.

Silica, alumina, etc 60

Green Rand 60

Viewing these reenlts generally, it is apparent, that while in some casee the efficacy of the marl would be asoribable in a degree to the calcareous carbonate or sulphate present in large proportion, in a great manj others the green saud ougb\ to be regarded as the chief if not the only agent in the effects. A dressing of many of these maris to the extent usual in the application of the Miocene shell marl would scatter upon the soil a proportion of green sand nearly as great as the average quota which is at present in use in New Jersey, and in the richer sorts, a much less proportion would be necessary than it is customary to apply where we shells abound.

We are struck, in considering the composition of these marls, with the happy variety of constitution which they exhibit, which, should there be any specific action of the respective ingredients on particular vegetables, which there is reason to believe is the case with one (the gypsum), will the more completely adapt them to the variety of crops to which the farmer would wish them to be ap- plied.

Some caution will be necessary in distinguishing the marls, con- taining a large proportion of green sand, from the dark greenish clays and sands which have sometimes been mistaken for them. These clays are always entirely destitute of fossils ; they have an astrin- gent or copperas flavor, and generally a strong sulphureous odor, though a slight smell of this kind is also observed in the best marls. The ooxurrence of small shells sparsely distributed and in a decom- posing state is very frequent in the good maris, though an almost total absence of shells is sometimes observed. Fine sparkling scales of mica, (not gypsum, as supposed by some), are generally present in considerable proportion, and have led those who speculated upon the action of the marl, to ascribe a large part of its efficacy to the supposed sulphate of lime or gjpsum contained in it. To distin- guish a marl of this kind from the dark blue Miocene marl, a slight attention to the embedded fossils wilt be sufficient. The saddle- shaped oyster, characteristic of the Eocene, and never found in the later deposit, would at once determine the bed in which it is found to be of the former description — while the common scallop or clam, which is never seen in the Eocene, would indicate the Miocene character of the bed in which it lies.

In concluding what I have to say upon this imporiant topic, I may be permitt to throw out the suggestion, that should the de- posit of which I have been treating, be found as extensive in its range and as useful as a manure as here anticipated, the districts of the state contiguoos to its western limits, as well as the region in which it occurs, might be expected to reap important benefits from its employment, rarts of Henrico and Hanover, and the lower part of Louisa, in which no marl exists, would be sufficiently con- tiguous to the Pamnnkey deposit to avail themselves profitably of its use ; and when the projected improvements in this region of the state shall present cheaper and readier means of transportation to the remote parts of the two latter coonties, as well as to a portion of Ooodiland, it is not extravagant to hope that this material may

be oonve.yed to those difltriots at rach a cost as will render it a profitable as it would be an efficaoions restorative to the exhausted and sterile soils to which ameliorating implications have of neoeasitjr hitherto been denied.

To other parts of the state in a corresponding position, perhaps similar benefits might be dispensed, and thus most of that portion of the state beyond the reach of the limestone which rmnges a little east of the Southwest mountain, would in time be brought under the beneficent influence of the marls of the western limits of the Eocene formation.

Region between the Head of Tide and the Western Fiahk

OF THE Blue Ridoe.

The various geological features of this extensive division of the state are peculiarly interesting, and at the same time difficult of in- vestigation. To trace the limits of the formation of an undoubted primary character, occupying the region towards its eastern border, and to ascertain the extent of the overlying rocks, connected with the valuable bituminous coal of Eastern Virginia, is of itself a task in which much time and industry could be advantageously employed. To investigate minutely the relations and character of the various rocks with which the auriferous quartz of the region adjacent to the western limits of the former, is associated, and to ascertain the number, direction, and relative value of these veins, so productive in the precious metal, would also be a business requiring much la- borious and discriminating observation ; while, in the remainder of the district of which we are now treating, multiplied and accurate researches, directed to numerous lines across its surface, would be iudispensable to correct |views of its geological details, to the re- moval of the many obscurities in whicn its structure in numerous points is as yet involved, and to the really useful development of its great mineral and agricultural resources. In the brief period al- fotted to the reconnoissance, therefore, the attainment of much mi- nute knowledge regarding this region was not to be anticipated, although while aiming at the determination of interesting points of generiu enquiry, it was always deemed an important object to collect useful details, calculated to throw light upon the resources as well as the structure of this region.

Before entering upon the description of the strata of primary and other rocks of a very ancient character, of which this region is in the main composed it will be most convenient to treat of the in- teresting formations, mduding the bituminous coal of Eastern Yir- ginia, as well as of the sandstones overlying the tide water borders of the primary.

Geoloot of the Bituminous Coal Field included in the Pbi-

MABT Region.

Of the extent and exact geographical limits of this truly interest- ing coal formation of Eastern Yiiginia, too little is yet known to

wammt more than a few words to designate its general position and relations to the other strata. We shall dwell, however, upon one or two points connected with its internal straotare, bf great moment to all those who are interested in the iforther development and working of its coal seams.

It will he apparent, hy a reference to the general profile or geo- logical section across the state, that the sandstones and their asso- ciated coal seams, which make np the formation hefore ns, rest in a narrow trough in the primary strata. Whether the group is char- acterized hy containing coal to a greater or less amoant throughout its whole extent, is yet a question, and one which can only he de- termined after minute and elaborate investigation. Traces of good bituminous coal are detected at intervals over a space of nearly thirty-five mUes in length, from the South Anna near its mouth to near the Appomattox river ; but there is nothing to assure us that the sandstone in which the coal occurs, does not range, at least in some directions, beyond the limits where the coal itself thins away and disappears. Toward the central part of the formation, — namely, within a few miles on either side of James river, — the coal appears to be' the thickest ; and it is there accordingly, where the deposit has alone been worked, that we can collect facts enough to lead to any general views of a practical bearing regarding the structure of this coal field. Where our section crosses it, — namely, through the estates of Mr. Wickham on Tuckahoe Greek, — the width of the coal tract is abont four and a half miles. It seems to expand in width as we follow it to the south side of James river, being in a section drawn through the Black Heath mines, probably eight miles across from the eastern to the western outcrop of the primary strata, which compose the fioor npon which the coal bearing group reposes. The probability is, that this is nearly the centre of the basin and the widest part of it, If we are to judge from the fact that the coal exists in gt'eater thickness here than at any place either ftirther north or south.

The thickness of these coal seams is very variable; the great lower mass which reposes within two feet of the primary rock, in the Deep shaft and other adjacent mines in Ohesterfield, is estimated to be forty feet from its upper to its lower surface. Over this there is another thinner seam, five or six feet thick, separated by a few feet of coal shale. A third, still thinner band of coal, is found be- tween these in some of the mines. Upon the opposite or western ride of the basin, two separate seams are wrought in several of the mines. At Anderson's mine, the upper seam varies from six to rixteen feet in thickness — the lower, separated from it by thirty feet of slate and sandstone, is from four to eight feet, and rests almost immediately upon the top of the nrimary rock. At Willis's and Grouch's mines, on the southeast siae of the coal field north of the river, there are also two principal seams, the upper being five feet, the lower about four feet thick, and separated from each other by eleven feet of slate. In both these points, as elsewhere, the upper seam is invariably the purest coal. We have thus, at a distaim of

nearly ten miles from each other, two looalitiea, ahowuig safficient correspondenoe in the relations of the seams to each o&er and to the adjacent strata, to establish the continuity of the same beda across the whole coal field.

In some of the shafts on Tnckahoe creek, as many as five sep* arate seams have been struck, of thickness sufficient to justify work- ing, and there exist many more of insignificant dimensions which are neglected. There are good local reasons in seyeral parts of the coal field on the north side of the river for believing that the seams occasionally coalesce, so that two become but one.

We do not conceive it essential to the obiects of the present re- port to specify anything more respecting the local details of the numerous mines in this coaJ field, than is requisite to make its im- portance and peculiar structure understood.

On the south side of the James river, an old mine, called the River pit, now deserted, contained at the depth of one hundred and thirty feet, a seam of coat twenty feet thick, but which, owiog to a close approach of the granitic floor to the sandstone roof, was so reduced in thickness as to be abandoned.

Upon the east side of the same portion of the basin in Mills's mines, the coal varies rapidly in thickness, from almost nothing to upwards of forty feet, and in one place to sixty feet, if we include thin bands of the coal shale. In the Midlothian pit the shaft is five hundred feet in depth, and the workings are carried to the depth of seven hundred feet below the soil. The coal is very variable in thickness, being worked at more than thirty feet, and in some places it is even thicker. In this mine, as in several of the acljacent ones, we have numerous instances of the coal filling up hollows as it were in the floor, being accumulated in saucer-shaped basins to the thick- ness of forty or fifty feet, and resting in comparatively thin masses upon the eminence$ in the same fioor. In some instances, these subordinate basins are almost entirely insulated from the rest of the coal field, and are presented under features which preclude us from supposing that they owe their shape exclusively to the numerous faults which intersect the strata. Upon the north side of the river, near Tuckahoe, the coal was reached precisely in the centre of a small, insulated, cup-shi4>ed depression. The coal, as it was pursued, was found to rise gently on all sides from the shaft, and also to thin away from a thickness of four or ve feet to two feet toward the edges of this shallow basin, which was several hundred feet in diameter, and but little disturbed from its original nearly horizontal position.

It should be remarked, that while the under surface of the coal resting almost in contact with the primary rock, assumes its uneven- ness of outline, the upper surface is also affected by similar undu- lations, though to much less extent, which only goes to show that the deposition of the coal did not sufiiciently fill un the original in- equalities upon the fioor, to make a perfectly level surface for the reception of deposits which succeeded.

Of the nature of the dislocations or faults, too little is at present

known to enable one to generalise or say moch upon this tnilj impor- tant topic The freatest number of pits being npon the eastern bor- der of the ooal field, it is there that the faults or troubles, as tbej are generally denominated in this region, are best seen. Along this outcrop of the coaT, there would seem to extend over a great space one or more very remarkable lines of dislocation, throwing up the ooal to the west by a very heavy fracture, so as to make of the same seam a double outcrop, and over a distance of perhaps half a mUe, bringing the subjacent granite itself again into view. We witnessi therefore, over a portion of the eastern side of the ooal field, two parallel ranges of collieries less than a fourth of a mile asunder. The Black Heath mines, the Union mine, and the Deep run pits are said to lie along the outer crop, though it is questionable whether one and the same fracture extends over so many miles of strata. The probability is, that several nearly parallel fractures will be found traversing this side of the region, and tending to. the intricacy and diflloolty of Buecessfttl mining. In fact, three eztenMve faults affect the strata near the Black Heath mines, the outer one causing the upthrow before stated, and the others producing heavy downthrows to the west

It would seem, that transverse to these more important and seri- ous fractures, which generally pursue a direction nearly parallel to the general line of outcrop of the coal, there are innumerable other more trivial breaks and displacements, sometimes straight, but of tener irregular in direction and dip, which still further intersect the strata, dividing them into a multitude of nearly detached and broken basins. An exact knowledge, more particularly of the great longitudinal faults, is especially desirable for directing with system the mining operations of this coal field.

There is one general fact of much practical interest disclosed in nearly all the principal mines of this whole coal field — It is, that the main body of the coal lies either in direct contact with the pri- mary rooks, or closely contiguous to them. This fornishes a highly important guide, or in fact the only unerring one, in the prose- ootion of new or intricate workings; for, it suggests the utility of making the primary rock the object towards whioi the mining should be pursued whenever a difficulty occurs in regaining the coal dia- placed by a fault; for, if we are surrounded by sandstone, we may oe sure that the chief deposit of the coal is to be reached by pene- trating across the strata towards the subjacent granitic floor.

The sandstones being all of them nothing more than the deMs of the subjacent primary strata reicemented, they resemble them occasionally so much as to render it difficult to the inexperienced to distinguish the two classes of rock ; though the discrimination in this case is all important The aid of a pocket magnifier will detect a less angular character in the materials of the sandstones than in those of the primary rock.

The general range or longitudinal direction of the coal field, or what is the same thing, the line of bearing of the outcrop of the coal, is nearly north-northeast and south-southwest. The structure of the

oofd field ifl that of rtrne bat rerj oblong baslii, composed of a tliiok seriea of yarioasly constituted sandstones superimposed upon two or tliree seiuns of bitaminons coal, themselves resting almost imme- diately in contact with the surface of the primary rocks of the sor- roanding region. Wherever the eastern boundary of the coal-field has been traced, the beds of gneiss, or stratified granite, are seen to dip apparently with considerable regularity to the west or beneath the coal, and in like manner upon the opposite or western edge of the tract, the same rock is known to have a general dip under the coal to the east ; suggesting the notion, at first sight, that the strata pass horizontally under the middle of the coal field. That this ia not necessarily the case will appear presently.

The usual angle of the primary strata to the horixon is about twenty-five or thirty degrees. Between the city of Richmond and the edge of the coal field at Tuckahoe, pursuing a progress west- ward, the dip of the strata for the first several miles is at a gentle angle to the east and northeast, varying sometimes to the north. Near the coal, the point towards which the strata are dipping is more nearly the northwest, or occasionally more west A similar change of dip is seen in nassing over the edges of the strata on the eastern side of the coal field upon the Chesterfield side of the river. Tracing the dip of the gneiss rock westward, from tlie western out- crop of the coal, we find it to be towards the southeast, or beneath the coal field, and this throughout a width of several miles in our course west, until we approach the Beaverdam creek; here, for a short space, the dip is altered to the west, but the easterly direction is after a while resumed, as we approach Goochland Court-House. Between five and six miles further on, or in the vicinity of Little Lickinghole creek, the dip is over more to the west. These various alternations in the position of the strata, are specified for the pui

Ce of showing how probable it is that the coal strata within the in were originally deposited in a valley formed by the meeting of an eastern and western dip ; in other words, upon the edges of the strata composing a iynelinal axis, and not upon a horizontally placed stratum of tne gneiss rock. The former view will help us more naturally to account for the very striking inequalities in the thickness of the bed of coal resting nearly in contact with the an- cient surface of the primary rock. Had the ancient rocky floor, upon which the materials that formed the coal were deposited, been the gneiss rock in nearly horizontal stratificaon, it is ha to con- ceive how anj subsequent dislocations of the whole group by op- throws and downthrows could introduce that remarkable aeffree of unevenness in the thickness of the coal seams over the small areas for which this coal field is so peculiar. Everything lends counte- nance to the opinion, that the surface of the primary rock, previous to the deposition of the carboniferous matter, was a valley of roll* ing outlines occupied by hollows and elevations, causing the first layers of matter which were thrown down to be deposited in greater Uiickness in some places than in others. As the lowest coal seam is separated from the crystalline rock beneath by only a very few feet

of shale, and in aome cases by none at all, it appears likel j that the distribtttion of the coal was made unequal in thickness from the yery commencement. There is ample proof that snbseqnently to the consolidation of an enormons thickness of sandstone over the coal, the entire series of beds, inoloding the underlying piimary strata, were reft by a number of extensive cracks, producing dis- pl&cementa of the beds, which combined with the original irregu- larity in the distribution of the coal itselt has caused the internal structure of this coal field to be one of excessive intricacy. These views are stated for the purpose of indicating the necessity of boring as the best and surest means of ascertaining the value of particular parts of the formation. For it must be plain that the ordinary mode of mining, applicable to other coal fields, may be ruinously fallacious when applied to this. The intricacy of the faults, and the changing thickness of the coal, are features calculated to bid93e and defy the anticipations of the miner. A profound knowledge of the nature and extent of the local disturbances around him, together with some general rules applicable to all coal mines, may enable him to approximate with considerable accuracy to the depth and position at which he is to meet the coal seam, but he can form little or no anticipation, from knowing its thickness elsewhere, what its thickness will be when he reaches it in the new place. In most eoal fields he may. The reason of the difference is, that in the pres- ent case the coal lies almost immediately contiguous to the undnlat.* ing sur£ftce of the primary rocks below, and must partake, especially in its lower surface, of the character of the plain upon which it was depodted. In most other coal regions the underlying rooks are either sandstones, limestones or slates, themselves originally hori- zontal deposits furnishing a level floor upon which the carbonifer- ous matter would necessiuily spread itself in an even sheet.

What is here said is not intended to throw a damp upon enter- prise which is pursuing th developement of this coal field ; on the other hand, we regard it as one of the most valuable deposits of mineral wealth within the area of Virginia.: ,Onr duty is by practical suggestions derived from the best sources within our reach, to pro- mote a sound direction to the enterprise and capital employed upon the mineral resources of the state— to teach caution where neces- sary, but not to discourage.

The very fine qualities of the ooal in this coal field, both for domestic uses and manufacturing purposes, together with the very enormous thickness of the deposit in many of the mines where it is pursued, hold out an ample guarantee, that if prosecuted upon a correct conception of ito internal structure, it must always prove a profitable region to the quarter of the state in which it lies.

There is one suggestion which we venture strenuously to enforce — the great importonce of preserving specimens of the various layers of rock penetrated by the shafts which are sunk from time to time, or in any borings that may be made. The rocks resting above the ooal are less liable to be affected by local variations th the coal itself, for reasons previously explained — and most important infer-

eDces might be drawn as to the depth of the coal, by comparing the rocks as they are crossed in snccession with sets of specimens of the same collected from the adjoining mines. Data will thns be rapidly accamnlated, from which we shall one day be able to infer mnch better than at present, the extent of certain fanlts or downthrows, the nature of which can as yet be only imperfectly understood from the evidences produced in the workings of the mines. Nor is it too much to anticipate being able to compute from information thus derived, the depth from the surface of the coal in some places in the interior of the basin.

To show the constancy of certain layers of rock in particular districts, and their importance as a guide in particular situations, we may adduce a case given by Professor Phillips of a band of fossil- iferons rock subordinate to a coal field in England. Speaking of a certain seam in the Yorkshire coal field, generally not mnch more than sixteen inches in thickness, and traceable from near Leeds to the west of Sheffield, it is stated, That it would have been impos- sible to have traced so thin a seam of coal along so extensive a range, without some peculiar facilities, some points of reference more dis- tinct than the varying quality of the coal, and the still more irregu- lar finctuations of the sandstones and shales. This coal seam is covered by a roof ' unlike that of any coal bed above the mountain limestone in the British Islands ; for, instead of containing only the remains of plants or fresh water shells, it is filled with a consider- able diversity of marine shells belonging to the genera Peeten and Ammonites, and in one locality, specimens of Orthoeeras, The uniform occurrence of these Peetens and Ammonites through so wide a range, over one particular thin bed of coal, and in no other part of the coal strata, is one of the most curious phenomena yet observed concerning the distribution of organic remains, and will undoubtedly be found of the highest importance in all inferences concerning the circumstances which attended the production of coal."

We may gather from this the importance of inspecting the sand* atones for fossil remains, should any exist

The mining shafts hitherto sunk in this region, have been con- fined exclusively to the vicinity of the eastern and western outcrops, from an apprehension, that more in the interior of the basin, the coal reposes too far from the surface to be readily reached. By fol- lowing the banks of the James river, above the mouth of Tnckahoe creek, it will be seen that the coal measures, —that is to say, the aand- 8tones,verlying the coal, alter dipping throughout some distance at a moderate inclination to the northwest become gradually almost horizontal, and continue so over much of the middle space between the eastern and western boundaries of the basin. This, certainly, hnplies the absence of any heavy dislocations afiecting the middle tracts of the coal field, and is one feature calculated to support the notion of boring for coal in that quarter. From what has been said respecting the probability of an undulating surface in the sub- jacent gneiss or granitic rock, and of the faults which intersect the

region, it becomee by no means improbable, that the coal in the cen- tre of the basin will be foond, in some places at least, sufficiently adjacent to the surface to admit of being profitably mined. Gen- eral analogy would lead ns to look for accumulations of coal in that qnarter, if not thicker, at all events as thick, as can be seen near to either outcrop. But the resources of the middle portions of the coal field can only be imperfectly guessed at, until there has been gathered a much larger mass of minute information from the bor- ders of the region. We do not yet know anytbiug definite regard- ing many portions of the limits of the basin, more especiaJly the western outcrop— and there is moreover much to do in following the coal where it is already tolerably well known.

The deepest shaft, that of the Midlothian mine in Chesterfield, is five hundred feet to the coal; and the workings connected with the aame mine, in consequence of some very heavy downthrows to the west, penetrate to the depth of seven hundred feet below the sur- face. There is some reason to believe, that still farther from the outcrop, there will be found an upthrow, bringing the coal once more nearer to the soil. It is possible that a shaft one thousand feet deep, would reach the coal in several places in the interior of the coal field.

In addition to the invaluable deposit above described, coal veins have been discovered in Prince Edward and Cumberland counties — and the rocks accompanying this mineral are known to extend over a wide area in this portion of the state. Their thickness compared with those of the coal fields previously described is, however, not considerable— and the seams of coal which have been met with, though containing a very excellent material, are on a comparatively limited scale. The probable extent of coal in this district, appears as yet undetermined, and will remain so until an examination of this

Sortion of the state has been carefully and minutely made. The iscovery of coal within a small distance of the base of Willises mountain, recently said to have been made, derives peculiar interest from the fact of the existence, in the same vicinity, of hematite and magnetic iron ores in great abundance.

8AND8T0in OVBHLTOrO THE PbIMABY RoOKS ALONG THEIB EaST-

Bbn Boundabt.

Sandstones of various degrees of coarseness are found in many places aloncr the eastern outcrop of the primary rocks, and extending for some distance below the head of tide. On the Rappahannock, in the vicinity of Fredericksburg, considerable exposures of these rocks are seen, the strata lying nearly in a horizontal direction upon the edges of the primary rocks beneath. At Falmouth, the two are seen in contact ; the latter forming the bed of the river, and the former resting horizontally upon them. At the head of the Pamun- key, the same rocks appear, dipping with some steepness to the east; they are again met with, gently inclining in the same direc- tion, a short distance below Richmond, and also in the neighbor-

hood of Fetenbarg, and at several points in Ohesterfield conntj. Further south they occur in the upper part of Greensville, and over a considerable portion of the county of Brunswick, and as is be- lieved, in portions of the adjoining counties.

In composition they are merely a mixture of quartz and feldspar, in rather loose cohesion — the feldspar often decaying rapidly on ex-

Eosure. In some varieties, the rounded pebbles are not larser than irdshot; in others, they attain a diameter of many inches. In certain localities, the sandstone has a fine dose texture, suiting it for various useliil purposes, and is employed to a considerable extent in building. The quarries in the neighborhood of Fredericksburg and Acquia creek present beds of great thickness of a homogeneous rock of tbis description, of which extensive use has been made in some of the public edifices in Washington, Richmond, and else- where. In the superior portion of these beds, lignites, silicified wood, and vegetable imnressiuns, are frequently to be seen — all of which contribute to render the examination of these deposits a sub- ject of much curious interest to science. Whether these sandstones be in reality cotemporaries of the analogous, though somewhat differing rocks of the coal measures of Eastern Virginia, impressed with peculiarities as to textnre and included fossils by some circum- stance of position and exposure in the progress of their deposition — or whether, as has been maintained, they are in fact of a decidedly more recent origin, are points only resolvable by cautious and dili- gent investigation.

In connection with these sandstones and the rocks of the coal measures, there occur in several places beds of earth sometimes hav- ing nearly the firmness of a soft rock, containing a considerable proportion of calcareous matter. In Prince Edward, where their existence was first particularly remarked by Dr. Morton, these clays and semi-rocks are occasionally so liberally impregnated with this substance as to furnish a strong and valuable marl. At other points, a mixture of carbonate of lime and carbonate of magnesia is found in beds of considerable extent, and having a texture similar to the materials above described. According to an analysis of a specimen of this substance from Bear Island, it consiets, in sixty grains, of —

Carbonate of lime 81

Carbonate of magnesia 18

Alumina 8

Silica 7

Loss 1

The occurrence, in many parts of this region, of clays and rocks thus abounding in calcareous matter, is certainly to be looked upon as a happy circumstance. Those interested in availing themselves of the fact, should have no difficulty in the application of these sub- stances in the raw, or if necessary, in the calcined condition ; fur.

even Bhonld tbey generally contain any notable proportion of mag- nesia, the more enlightened experience of the present day wonld seem to shew that the presence of that earth is rather favorable than injarions when associated with lime, and in some cases almost equal in efficacy to calcareous matter itielf.

There is moreover another economical aspect in which this material may be regarded. From the large proportion of magnesia it containn, it would famish an admirable resource for the mannfac- tore of that eartli in the state of pure carbonate, or what is at pres- ent an object of much more extensive commerce, I mean the sul- phate of magnesia, or epsom salts.

Of the Pbimakt Rocks.

As already stated, the extent of this portion of the state is not aconrately known. Its eastern limit coincides in general with a transverse line crossing our principal rivers at their lowest falls. Various species of gneiss rocks and granite are exposed at these points, some of which are beginning to be known for their valuable qualities as a material for building. At Richmond these strata occur in heavy beds inclining at various ai\gles to the east, and are well exposed along the canal for some distance above the city. The rock at Ridimond is a grayish white gneiss of great density, and of snoh a degree of hardness and toughness combined as to impart the donble advantage of durability and facility of being wrougnt. Its predominant constituents are feldspar and quartz. Dark mica is sparsely distribnted through it, so that its prevailing colour is a light grey. It is in consequence of its large proportion of feldspar that the rock in many places is observed to be decayed to so great a depth below its original surface. Those varieties will be found most durable for architectural purposes in which this excess of feld- spar does not exist. At the falls of the Appomattox near Peters- burg, we find a well characterized variety of granite. It possesses a coarse crystalline structure, and consists of yellowish white feld- spar in distinct crystals, with a smaller proportion of quartz, and a trivial amount of white or light coloured mica. Other varieties of a more compact and fine texture occur in the same neighbourhood. At some distance further west, in general the rock is a gneiss, con- taining a much larger proportion of mica. In the upper part of Goochland, and the other counties at corresponding distances above the falls, gneiss of a more compact texture prevaSs. A quarry of this at Columbia furnishes an admirable building material. " Its texture is nearly that of a compact sandstone, and it is colored of various shades of grey from the scales of black mica which it con- tains. A gneiss of a very peculiar description occurs in WiUiss mountain, Buckingham, associated with several interesting min- erals. The rock is generally of a rich pink or purple, owing to a large proportion of oxide of iron disseminated through it, causing it moreover to be very ponderous. The mica and angite, which appear to be large components of the mass, give it a very brilliant

aspect, especiallj when recentlj fractured. It is sometimes stadded witli minute cells, containing liematitic oxide of iron. Nearly the whole of the principal peak of the mountain is made up of this beautiful rock, which, rising in the form of a wedge to the height of several hundred feet, presents a narrow wall of nearly vertical strata along the summit. The dtp is w est, and the fragments which have tumbled to tlie eastern base have rendered this the easiest direction of ascent. From its hardness, and the indestructible nature of its materia this gneiss will some day possess a value independent of that founded upon its colour, which will bring it into use as an article for building. At the base of the mountain schorl occurs in great abundance, crystallized in long prisms in quartz. Asbestus and kyanite are also found together, with several other minerals chieflj interesting in a scientific point of view.

Westward of this belt of gneiss the rocks assume various inter- mediate characters, until at length the truly crystalline structure is lost, and numerous forms of slate of very peculiar and equivocal features make their appearance. At what precise points the rooks of unequivocally primary character terminate, future researches must ascertain.

In pursuing the line selected for the accompanying profile, the gneiss which is found dipping east for some distance beyond the western edge of the bitummous coal formation, assumes a westexn dip which it again changes for an eastern one, ar which another change occurs, and the western dip now continnesto the neighbour- hood of Columbia. Between this point and Bremo, the rocks become vertical, and further west the dip continues with scarcely any ex- ception, easterly, but very steep as far as the Soutliwest mountain, and even in many lines almost without alteration, to the western base of the Blue Ridge.

The soils of the primary region, except where the rocks accom- panying the coal exist, are remarked for the quantity of clay, often of a very ferruginous character, which they contain, llie feldspar, which, as already remarked, enters largely into the composition of our gneiss and granite, is in some of its forms peculiarly liable to undergo a decomposition by exposure to the atmosphere. The alkali contained in it is gradually dissolved out, and the clay and silica, its other constituents, fall to powder, and thus furnish the materials for soil. At the same time, the quartz and mica, no longer cemented by the interposed feldspar, also separate and mingle with the gen- eral mass of clay or sand. The hornblende, possessing much oxide of iron and some lime, produces when decomposed, a deep red earth, which, in virtue of its composition, is generally found pro- ductive.

In accounting for the highly ferruginous soils presented in many places in this district, as at Beaverdam in Goochland, it might at first view appear most plausible to regard them as the product of disintegrated hornblende, derived from the subjacent errata, and certainly in some localitiesthe colour and qualities of the soil may be justly referred to this origin. But there ore numerous instances in

which the superficial earth or clay is very deeply tinged, while no rock of this description exists in the neighhorhood. Even overlying tlie sandstone of the coal measures, where the occurrence of this minernl would he next to impossible, soil of a deep ferruginous as- pect frequently presents itself. Moreover, in general this red soil forms merely a superficial stratum, often only a few inches in thick- ness, while the earth beneath, the obvious product of the decompos- ing gneiss or granite, has a white or grey colour, and scarcely any mixture of the tint which prevails on the surface. In all these cases we must look for the source of the red soil in the extensive region to the west, where nearly all the rocks give rise to it by decomposi- tion, and we must regard it as having been transported to the spot on which it now rests, by some of those sweeping diluvial currents whose action is otherwise attested by evidences of a conclusive character.

The soils containing isinglass or mica, as well as those abounding in the clays derived from the decomposition of feldspar, though in their natural state rather deficient in productiveness, nave generally been found to receive great benefit from the application of lime and calcareous manures; and the district in question may reap great advantage from an application of either. Its vicinity to the Eocene shell and green sand marls, as already indicated, is likely at some hot remote day, to prove eminently beneficial to its agriculture, and it were to be wished that the farmers who are interested in its im- provement would promptly take advantage of such facilities of transportation as are likely soon to offer, for the purpose of availing themselves of the resources which nature has placed so completely within their reach.

In the neighborhood of rocks where the feldspar is compara- tively abundant, the dirintegrating process gives rise to a clay of a pure whitecolour, and almost impalpable texture. This is the Kaolin of the Ohinese, one of the essential ingredients in the composition of Porcelain. Numerous rich deposits of it are to be found in this

Eortion of the state. In Goochland, an extensive bed of this earth as lately been discovered on the estate of Mr. Triplett. Its colour is a dull white. Between the fingers it has the smoothness of the finest fiour, and with the exception of a few scattered grains of silez, the whole mass is a perfectly impalpable powder.

By a careful analysis of some of this eai-th, I find its composition to be as follows :

In twenty grains, Silica 10-78

Alumina 6*00

Water 2*90

Loss '84

In numerous places in Goochland, Cumberland, Buckingham, and other counties similarly situated, the Porcelain earth occurs in extensive beds, and in many cases in as available a condition as

above described. This fact, taken in connection with the known existence of feldspar in the same region, points to the probable in- trodaction at no distant day, of an important branch of mannfac- tare in the state. — I allude to the fabrication of the finer description of china or Porcelain, in which sach excellence has already been at- tained by the employment of similar materials in Pennsylvania.

The region on the western borders of that which we have been describing is marked by the occurrence of talcose and argillaceous slates, micaceous and garnet slates chlorite slates, steaschisc various modified rocks, and numerous veins of auriferous quartz. The pre- cise nature of many of the rocks occurring in this, which for tho sake of distinction, may be celled the gold region, cannot be deter- mined without close and persevering attention.

Of the Aubifebous Rocks.

A general examination of this district suggests a variety of prob- lems of a scientific as well as practical nature, which it would be premature at this time to attempt to resolve. The number and ex- tent of the quartz veins is one of the most interesting as well as im- portant features in the geology of this region, and it is greatly to be desired that minute observation be directed to the tracing of these veins through the state as far as practicable; to the determination of the general value of each vein now wrought, as well as the study of the efficacy of the various processes adopted for the purpose of separating the gold from the materials with which it is intermixed. There can be no doubt, that with the means now most commonly in use, a large proportion of the precious metal is lost and thrown out with the gravel from which only the larger masses of the gold have been separated. At one of the mines visited during the recon- noissance, the sand and gravel, after having been twice subjected to the usual process of washingi, were found sufficiently productive to yield five dollars a day to each of the two persons who were wash- ing it a third time. In some of the mines, more scientific and effect- ual means, both of conducting the mining operations and the sub- sequent process for separating the gold, have been introduced, and when these improvements shall have become more generally known, we may hope for much more profitable returns than in many in- stances have been hitherto obtained. The amazing richness of many of those veins has attracted enterprise to this branch of mining to such an extent, that the exploration of the most promising auriferous veins has of late been very actively and snccessfnlly pursued.

In Spotsylvania and the adjacent counties, Orange, Louisa, Fluv- anna, and Buckingham, numerous veins have been wrought for some time, from many of which rich returns have been procured, and under improved modes of operation a still larger profit may be expected. Any detailed account of the various workings now in progress would be inappropriate in the present report, even if the state of our knowledge were such as to warrant statements of a positive nature. Some account of the structure, position and con-

tents of the yeins may be introdaced as generally applicable to the whole.

The material of the veins is a variegated quartz, soraetimes trans- Inoent, at others opaqae. It is generally of a cellular structure, fractures without much difficulty, and in many instances contains a considerable proportion of water dispersed through its substance. Its surface, recently exposed, displays a variety of tiute of brown, purple and yellow, of sucIj peculiar aspect as to resemble a tliin tacauer spread unequally over the rock. The cavities are often fiUed witn a bright yellow ochre, or hydrated peroxide of iron, which generally contains gold in a state of minute division. Sulphuret of iron (Pyrites) is another accompanying mineral, which in many mines occurs in considerable quantities. At Morton's mine, (Buck- ingham,) it is peculiarly abundant, and there, as in otherplaces, gen- eraUy contains a portion of combined gold. In the Union mine, near the Rappahannock, some of the auriferous veins consist largely of the Pyrites, which here contains so much of the precious metid as to render the extraction of it a matter of profit. This Pyrites, in all probability, was at some former period more generally diffused tlironghout all the auriferous veins, and by its decomposition gave rise to the peroxide of iron, with which the quartz is always more or lees imbued, while the gold existing in it was deposited in the cells and fissures of the quartz. Silver is occasionally found in con- nection with the gold, and the sulphurets of copper and lead have been discovered in a few instances in the auriferoas rock.

The rocks forming the boundaries of the auriferous veins vary very much in different localities. Talcose slate, chlorite slate, and a variety of these abounding in garnets, are the most usual. They are commonly of a soft texture, yielding readily to the blast, and even to the pick or spade sometimes. Instances occur, however, in which the walls of the vein are of such hardness as to greatly increase tlie expense and difficulty of procuring the ore. Of this a striking example is exhibited at Morton's mine, where the rock is removed with difficulty even by the blasting process, while at Booker's and some other mines its texture is so rotten that it rather presents the appearance of earth than rock. Yeins like the latter, under favorable circumstances, would give rise to what are technically called depatit mineSy in other words, collections of clay and sand and gravel, enclosing a portion of gold, all which materials have been removed by the action of torrents or streams from their original position in the vein, to some aljacent ravine or hollow, in w4iich they have been quietly deposited. The rocks adjacent to the quartz are often auriferous, and in some instances have been found as pro- ductive as the quartz itself. Of this, several striking instances occur in the mines of Buckingham; and I believe that in many other localities the same condition would be found to exist.

It has already been state<l that nearly all the rocks of this region dip steeply to the east, and it is found that the auriferous quartz veins conform in the main to the inclination of the enclosing strata. The quartz is not, however, to be regarded as an interstratified por-

tion of the series, which would imply its cotemporaneons origin with the strata.

The form and position of the veins are rarely snch as to justify this view. Instead of lying in uniform thickness between the walls of the adjacent rock, and with surfaces of slight irregularity, we Und the auriferous veins in most cases very irregular in their forms : at one point having a thickness of several feet ; at another very near to the former, contracting so as only to measure a few inches across. Again, in many cases the vein divides, and the separate portions afterwards unite or send off other branches.

Tlie bounding surfaces too, instead of being nearly uniform, ns in the strata of the neighboring rocks, are rough and broken, send- ing off numerous small veins of quartz into the enclosing strata.

In Mortons mines, the width varies from seven feet to five or six inches. In Booker's the vein forks, thins, and as frequently widens. At the Union mines on the Rappahannock, the breadth varies in some cases from six inches to nearly three feet.

In fact, from the dimensions of the vein at any assumed point, no certain inference can be drawn with regard to its extent at other and remote positions. This irregular structure, while it diminishes confidence in the constancy of a large and fertile vein, at the same time furnishes grounds for continuing the examination and prosecu- tion of one, which by its contraction has become of little or no value, as an enlargement at a small depth beneath, may reveal an abundance of productive rock.

Another fact of some practical importance, and one which, to- gether with those above stated, has a direct bearing upon the ques- tion of the origin of the auriferous veins, is this, that although in the main, the dip and direction of the vein conforms with those of the enclosing strata, the correspondence is far from being exact, and in many instances, while the inclination of the neighb(ring strata remains unchanged, that of the vein undergoes very striking alteration. At Mortons mine, already referred to, the dip near the surface is about twenty degrees, while, at some depth beneath it becomes forty-iive degrees; and similar instances of variation might be adduced by reference to other localities.

It would thus appear, that these numerous veins of quartz are not to be regarded as deposits coeval with the regularly stratified rocks among which tiiey are found, since in that case their position and structure would exhibit a like degree of uniformity, but as matter which, subsequent to the production of the neighboring rocks, was forcibly injected between them by igneous agencies from beneath, rising in the directions of least resistance, and therefore, generally, though by no means uniformly, following the plains of stratification of the rocks through which they passed. Instead, therefore, of considering them as beds like the adjoining strata, as some writers have done, we would incline to class them among tein§ of injeetion, of which numerous instances occur in other parts of the globe. "We are the more persuaded of the correctness of this view of their origin, from the consideration that throughout all the

region in which the qnartz veins are fonnd, very peculiar modifica- tions in the structure and ooinpoaition of the surrounding rocks are invariably to be observed — modifications for which no adequate cause can be fonnd in tlie other igneous rocks which occasionally occur. In the Blue Kidge, the Southwest mountain, and in numer- ous other lines, it may always be remarked, that wherever the modi- fied rocks occur, indicating an igneous action, more or less intense, which has wrought a change in their structure, and induced new arrangements of the ingredients of the rocks, heavy veins of quartz are sure to lie in their immediate vicinity ; while through the body of the rocks themselves, counMess minute veins of the same mate- rial are seen diverging from the principal mass, and imparting vari- ous metamorphic characters to the substances with which they are in contact.

Besides the anriferons veins of the region in which gold occurs, there exist many other veins of quartz agreeing with those which have been found productive in nearly aU particulars, save that of confining a valuable proportion of the precious metal. It is highly probable that none of these veins are entirely destitute of gold, and m many instances no doubt the prosecution of the vein would lead to the discovery at other points of it, of an ore sufficiently ricli to reward the labor of the extraction. Indeed, it must be looked upon as probable that the auriferous character more or less pervades the quartz veins generally, even as far as their western limit in the Blue Ridge. The striking similarity in the character of them all, and the obvious cotemporaneoutnesa of their origij would seem to give great plausibility to this opinion ; and if we are to credit the state* ments of the discovery of gold in the western part of Albemarle, and at one or two points equally remote from the gold region, as usually defined, we can no longer doubt the propriety of regarding the Blue Ridge as the proper western boundary of the auriferous rocks. A careful investigation of the numerous large quartz veins ranging along the valley between the Southwest mountain and the Blue Ridge, becomes in this point of view a matter of great import- ance; and should the auriferous ciiaracter be found pervading these veins, as is not improbably the fact, the extent and value of the gold region of the state will scarcely have a parallel upon the globe.

Of the KfioAosoufi and Gabnet Slates, Siuoious Slate, Whet- stone Beds, Roofino Slate, Steasohibt, Iron Ore, eto., of

THE BbOIOK WE8T OF TBB GnEISS.

In pursuing the line indicated in the section, after leaving the gneiss and hornblcDde slate, which extend some distance above Co- lumbia on both sides of the James nver, the rocks met with are chiefly various kinds of slates and schists, penetrated occasionally by the veins of auriferous quartz already described, and furnishing mate- rials for building and other uses. Analogous beds are also met with in the regions northeast and southwest of that here referred to— - ranging through the state in a belt comprehending what is usoallj

termed the gold region, and bonnded on its western side hy the nar- row belt of limestone lying east of the base of the Southwest momi- tain. The descriptions aboat to be given of these varioas rocks and other materials, though foanded upon an examination of them as they occur in Buckingham, Fluvanna, Louisa, and one or two otlier counties in the range, will obviously be applicable, with some modi- fications, to the corresponding beds occurring in other portions of the same belt.

MiOACEous GABifET Slate obibdVeyb Maple Slate.

After leaving the gneiss and hornblende slate a little below Bre- mo, we come upon heavy vertical beds of a Micaceous alatc, in which are multitudes of half developed garnets, and sometimes crystals of cubical pyrites — giving to the surface of the rock the appearance of numerous knots, around which the fibres of the stone are beantifnl- ly curved, so as closely to resemble the shading of the birds-eye maple ; and hence, in the absence of any specific designation, the one above used may be considered as appropriate, at least for ordi- nary purposes. This rock has the lustre and color of plumbago, and evidently contains much mica. It possesses considerable hardness, and may be separated in the quarry in large regular masses --and hence for slabs, pavements, and general building use, may be advan- tageously employed. At the Buckingham iron works it has been used in the furnace stack, and has been found to answer well.

The siliciaits micaceous slate occurs a little west of the former, and has a sensible dip to the east, though almost Vertical. This rock is of a light, yellowish brown color, contains a small proportion or inida, some feldspar, and a large amount of silex, apparently in grains ; and in fact, at first view, presents the aspect of some sand- stones, though probably more nearly allied to the mica slates than any other known rocks. It may be quarried out in long rectangular prisms, with surfaces nearly as smooth as if formed by the chisel, and from its hardness and durability under exposure, is to be looked upon as a valuable rock. When intensely heated it becomes glazed on the surface, and is used for the fioor of the iron furnace at New Canton.

Associated with these beds is one containing crystallized garnets in great numbers, and sometimes of exceeding beauty. This rock often contains much chlorite, and presents a general greenish aspect. Large quantities of it have been quarried in building the dam at New Canton, and a portion peculiarly abundant in the garnets, has recently been introduced in the furnace as an auxiliary flnx — the large proportion of lime contained in the garnets fitting the rock peculiarly for this purpose, while at the same time it yields a con- siderable amount of iron.

The whetstone beds, which occur among the siliceous and other slates, also furnish a material of high value. The texture of this stone is exceedingly close and fine; it possesses a proper dejjree of hardness and great permanency under atmospheric exposure. Its

apparently fibrons strnctore, and the long shape of the masses which are separated in the quarry, give it the appearance of a log of wood, partially decayed. The trial of its qaalities as a whetstone, made in Fluvanna, Kockhridge, and the neighboring counties, amply demonstrates its excellence for this purpose, and in some instances, experienced raechanica have evinced their sense of its superior vaJue by laying aside the Turkey oilstone, and substituting this in its place. One of the most interesting and valuable of the slaty rocks of this region is the roofing slate which occurs in a thick bed west of the strata which have just been described. This makes its appearance on both sides of the James river, dipping east at an angle of about eighty degrees with the horizon. In Buckingham the bed is largely exposed in the neighbourhood of New Canton on Slate river, and the qnarry at present wrought by the enterprising owner, Mr. Sims, yields a material which will bear comparison with the better quali- ties of ttie imported roofing slate. In texture, density and capacity of resisting atmospheric agents, it can scarcely be excelled by a simihir material in any part of the worid. This quarry was first opened to procure slate for roofing the capitol ; and notwithstand- ing it has been thus long known, and its value established, but little further nse has been made of it, until the activity of the present pri>prietor has again brought it into notice. The buildings of the University will soon be furnished with a complete covering of slate from this quarry. The bed of slate wrought by Mr. Sims has an average breadth of sixty yards. The rock splits with great regu- larity, presenting a smooth surface, and having such strength and flexibility as to admit of being separated, by iron wedges, into sheets of one hundred square feet, and not more than an inch in thickness. There are many other places in the neighboarhood from which slate of the same kind may be procured, and several small quarries' have been opened. Increased facility and cheapness in transporting this valuable article to Richmond and the seaboard, will, no doubt, at some early day, bring it into extensive use in our principal towns in that direction, and will render the quarrying and preparation of it a profitable business. During the last year, Mr. Sims brought into a state for the market, six hundred squares of this slate, at twelve dollars per square ; and this with bat few hands and very imperfect arrangements.

The BteaaehtMt or toapstone which occurs west of the slate, and may be seen near the month of Hardware river, both in Fluvanna and Buckingham, though not as valuable as other beds of a some- what similar description, to be hereafter described, is nevertheless capable of being very usefully employed. In hearths, jambs and otner parts al>out the chimney, it is found to possess useful quali- ties, and its texture is such as not only to render it easy of separa- tion in the quarry, but also to make it readily wrought under the chisel. At Breroo it has already been brought into use.

Several yeins or beds of iron ore exist in Buckingham in the re* gion of the gold reins and slates, and ore of similar description makes its appearance in Fluvanna, Louisa, etc. In the former county

indications of this deposit have been distinctly traced tfaroughoat a line of seven miles, and the proprietors of the furnace at New Can- ton have assjred themselves of its continuity for two miles. West of the principal vein is another at the distance of one hundred yards: a vein of friable slate dipping east occupying the interval. In the first or principal bed a continuous mass of ore has been uncovered, whose length is about sixty feet, and average breadth fifteen. As yet no certain opinion exists as to the depth to which it reaches below the sni-face. This ore is generally embedded in a brownish yellow ferruginous clay, and fragments lie scattered over the surface in the neighbourhood of the bed. Througii a long but narrow belt in Louisa, Fluvanna and Buckingham, and in fact throughout the whole length of the gold region, so called, these sur- face indications may be traced. The ore is a hematite in irregular masses, sometimes cellular and frequently mammillary. The cells often contain acicular white crystals of groat lustre. The colour of the ore varies from a yellowish to a blackish brown. Its hard- ness in different localities also differs, and in the immense mass above described, is such as to render blasting necessary. There is some difference as to the proportion of oxide of iron contained in the ore from the two veins near New Canton, and a mixture of both varieties of ore has been advantageously used in the fur- nace now in successful operation. As early as the revolutionary war iron was manufactured from the Buckingham ore, but until recently this valuable resource has been almost entirely neglected. Tlie limestone on the western edge of the county furnishes the fiux em- ployed in the smelting of this ore, which, under the superintendence of Mr. Dean of New Canton, is now conducted on a scale of such extent as to give a weekly product of between thirty and forty tons of pig metal, much of which is of a superior quality. Ore of pre- cisely the same description is found likewise in Uie gold region above Fredericksburg, and as in the present instance, in the vicinity of the garnet slate. From the curious association of this ore with the auriferous rocks, it might be expected that in the operations of the furnace a portion of the precious metal would occasionally ap- pear, and accordingly it has been discovered in fine specks in the cinder of the Buckingham works. Magnetic iron ore of a very vdu- able quality occurs at the base of Willis's mountain in Buckingham, and is found at several other places in corresponding positions.

Of the Limestone and Marblk east of the SorxHWEST and

Geeen Mountains.

This belt of rock, represented on the profile as it occurs on the Mechunk creek, and in several other places, may be traced with but little interruption through several counties lying in the range there indicated. In proceeding south it appears to become broader, and to be, subdivided into several ledges, presenting various aspects in different localities. Wherever examined it has been observed to have an eastern dip, in some places steep, in others gentle. In Al-

bemarle county and at Warminster, its struoture approaches to slaty, and its general colour is bluish grey, frequently veined with white crystallized calcareous spar. On the Mechunk it lies on slate often of a talcose nature, and its posicion is such as to render the labour of quarrying comparatively small. At Warminster it is also associated with a talcose schist and a white silicious rock of fine grain and considerable hardness, which has often been mistaken for marble. Along the banks of the James river, from this point to the neighbourhood of Lynchburg, cliffs of tlie limestone from time to time are seen, sometimes presenting enormous masses of the rocl iiiimediatdy on the waters edge. The breadth of the belt exposed in this directiou is obviously much greater than farther north, and the character of the rook in some localities is such as to render it of the highest value. Near the mouth of Tye river and on the liockfish, a true marble is found of beautiful whiteness, and of a texture which renders it susceptible of a fine polish, as well as of being readily wrought by the chisel. A few miles from Lynchburg, in Campbell county, a good marble is likewise found, and limestone is abundant in the same neighbourhood. A white and very ponderous rock occurs in contact with the calcareous stratum. This is sulphate of Baryta, which from its texture and colour has by some been supposed to be marble. Farther south these beds of limestone of various qualities are known to occur, but have as yet been little examined. The probability is that they are continued throughout the state in the same general line, perhaps spreading out in ap- proaching the borders of North Carolina. In Bedford county, at a point considerably west of the general direction of this belt, marble is said to exist, but no specimen has been procured in the reconnois- sance. Minute investigation of the region indicated by the localities above mentioned, and extending entirely across the state, would in all likelihood be fraught with valuable results. Leaving out of view the marbles to which we have already referred, the beds of lime- stone existing in tliis district of the state furnish a resource whose value to tlie agriculture of a wide tract of country it is beyond our power to calculate. Every bed of limestone developed in such an examination ought to become a source of agricultural improve- nient to an extensive neighbourhood ; and were our farmers once properly impressed with the value of calcareous matter as a manure, especiaUy on the soils of the region now in question, an earnest zeal in the discovery and use of these resources would, quickly become general, and an important district of the state would be rescued from unprofitable and disheartening cultivation. Lying adjacent to the slaty and micaceous soils east of the South-west mountain and its prolongation, this belt of limestone furnishes the very material by which under judicious management they may be redeemed from comparative sterility. In Orange, Albemarle, Louisa, Fluvanna, Buckingham, etc., the application of lime procured from this source might with proper arrangements, and the increased facilities which are likely to be afforded to transportation, be made to effect an en- tire revolution in the agriculture of the country — and even in Gooch*

land and other counties comparntively remote, similar benefits might be secured at a small additional expense. It is perhaps not gener- ally understood that the slatj and micaceous (or isinglass) soils, such as prevaU in the districts referred to, are known to be peculiarly susceptible of improvement from judicious liming. The experience of farmers in Maryland and Pennsylvania has amply shown that this is the case — in those states soils thus characterized are limed to a large extent, and always with the most decided benefit. Experi- ments made in Albemarle and other places with the lime procured from the limestone beds of which we are now speaking, have dem- onstrated its value upon the slaty soils in the vicinity, and nothing is wanted to diffuse these benefits extensively through the surround- ing country, but a just appreciation of the utility of liming, the in- troduction of economical and efficient modes of burning the lime- stone, and the selection of such quarries as from the nature of the rock, are calculated to yield a product containing the largest quan- tity of lime.

A mistaken impression has prevailed, that this limestone always yields a comparatively poor lime ; and to this may in part be ascribed the little use which has heretofore been made of it, either in agri- culture or building.

It will be seen by the following statement of results of analysis, that the amount of carbonate of lime present in these limestones, is in some cases large, and that in no instance can the lime be re- garded as a poor one. I have annexed a column, showing the pro- portion of lime corresponding to 100 parts of the limestone :

Carb. Lime. Lime.

100 of blue slaty limestone, Warminster .. 81.4 45.5

100 of blue with white veins, " . 88.4 49.5

100 of blue, slaty Mechunk, 83.2 46.6

The extensive exposures of limestone on both sides of the James river, existing in the neighbourhood of Lynchburg, New Market and Warminster, from their very favourable position as regards the facili- ties of conveyance, are calculated to become peculiarly valuable. Indeed, no position could be found in the state in which lime-burn- ing could be conducted on a larger and more profitable scale. By the introduction of the perpetual kilns now generally used in the extensive lime-bnrning establishments of the eastern states, much fuel would be saved, and all the lime which the rock is capable of fur- nishing would be obtained ; while, by the plan nsually pursued, much wood is wasted, and the limestone, particularly of the slaty kind, is but imperfectly calcined. These improvements once adopted, and the better kinds of limestone selected for the kiln, there appears to be no reason why this favoured region may not be able to furnish onr - eastern towns with lime more cheaply than it can be imported from abroad, at the same time that it is imparting to the surrounding country the benefits of an improved productiveness and a wiser sys- tem of cultivation.

To what has already been said concerning the marble of this re-

gioo, nothing positive can be added withont fnrther inyestigatlon. It may, howeverf be remarked, tbnt from the specimens ready seen, particalarly the white marble from Tye river, there is reason to hope that this, likewise, may become an object of innch value to the district in which it occurs. The Tye river marble, and one or more analogons veins, have all the characters of a statuary marble of fine quality, and should not some peculiarity, as yet nn perceived, prevent their application to the purposes of the sculptor, they will no doubt be looked upon as very valuable possessions.

Of the RocKSj Obes, Soil, &o., of the Region West of the Limestone, as fab as the Westekn Flank of the Blub

RiDOB.

This extensive district of the state comprises a great variety of aUtea, sandstones, schists and other rocks, almost uniformly dip- ping east, and in general at a very steep angle. Quartz veins are frequently met with, some of which are believed to be aurifer- ous, thoagh as yet, no profitable mine. of the precious metal has been opened in them. Beds of trap occasionally occur, the mate- rial of which, from its dark colour and extreme hardness, is usually known by the name of Iran Rock, In some portions of the dis- trict, hornblende enters largely into the composition of many of the rocks, while in others, talc and chlorite appear chiefiy to abound. But it ia important to remark, that amid all the diversities in the mineral character of the strata, a very general conformability of dip may be observed. Looking merely to the mineralogical constitution of the rocks in many localities, an impression of the undoubted pri- mary character of this district would naturally arise. But when a more genial exploration of the region discloses the existence of extensive beds of genuine sandstone, and conglomerate rocks fre- quently in contact with the former, and having the same uniform inclination, we are unable any longer to maintain this view. This opinion, however, would be found incompatible with the results of a more extensive observation of the rocks, of which this region principally consists. It would then be found, that a large portion of its area is occupied by beds of genuine sandstone and conglomer- ate rocks, and that the chief part of those strata, which at first view might be regarded as crystalline and primary in character, are in reality modified forms of sandstones and conglomerates, which, tlirough intense igneous action, have been made to kssume appear- ances more or less closely resembling those of rocks of the latter description, thus disguising, almost entirely in some cases, the origi- nal seaimentary structure by which they would be characterized as not appertaining to a primary formation. It is the existence of this curious class of rocks in many parts of the region in question, as well as the occurrence of occasional beds in which no appearance of the sedimentary origin can be traced, which imparts to the minute geological investigation of this part of the state, so much of scien- tific interest, and at the same time renders the task of such an ex- amination laborious and difficult.

Whatever may be our view of the origin of the truly crystalline rocks which occasionally occur throughout this region, numerous sectional examinations, which have been made with the view of solving some of the difficulties connected with its geology, have com- bined in establishing this interesting conclusion, that by far tlie largest portion of its surface is occupied by rocks which do not belong to the primary system, while they have, at the same time, served to display the modifying effects of igneous agents, as mani- fested in the changed structure of many of these rucks, on a scale of wonderful variety and extent.

Early in the present report, allusion was made to the prevailing errors on the suMect of the true geological character of this region, inclusive of the blue Ridge ; and enough has already been stated in regard to the structure of the region, to satisfy the enlightened geol- ogist of the entire impropriety of the designation of primary wJiich it has heretofore uniformly received. The further particulars about to be given relative to some of its rocks, chiefly those of economical value, will serve still more clearly to evince the inaccuracy which has hitherto prevailed with regard to the limits of the great geologi- cal subdivisions of the state, as well as to display the practically valuable results which are linked with an investigation which at first view appears to be purely scientific in its character.

The rocks of the South-west mountain and its prolongations, and of the country within a few miles on either side, will first be de- scribed, after which some account will be given of those lying more to the west, and in particular of some portions of the Blue Ridge.

Pursuing the line indicated in the profile, after leaving the bed of limestone, already referred to, we meet with slates and schists in some places of a micaceous and talcose, and in others of a siliceous nature, and so friable as to be of but little use in building ; compris- ing occasional beds of a denser texture, and more resembling roofing slate. This brin<rs us to the greenish and dark blue argillaceous sandstone of which Carter's mountain, as well as much of the region on its eastern and western flanks, principally consists. Beds of grey and yellow sandstone occasionally present themselves among the darker rock, and these are uniformly of a coarser texture, and in many cases are rapidly decomposed by exposure to the air and weather. Quarries of the dark greenish and bluish rock have been opened in many places, and furnish a material for building which can hardly be excelled either for strength or permanency under ex- posure. Much of this rock, however, is so hard as to prove diflUcult of separation in the quarry. This is remarkably the case with the green variety, which occurs very abundantly for a mile or two east of Meriwether's bridge on the Rivanna. This rock bears the strongs CvSt marks of intense igneous action in its flinty hardness, and in the large quantity of green Epidote which has been developed through- out its structure. It is, moreover, always intersected by veins of quartz, so that it would be difficult to find a mass of considerable size, in which many of these veins would not be visible. It is fur- ther to be remarked, that always in the vicinity of these quartz

veins, the rook is hardest, and displays the largest portion of the green colouring iiiaterial. All these tacts would seem clearly to point to the quartz as having heen directly concerned in the various modifications which the rock has ohviously undergone. In further illustration of thit> view, it may be added, that often in the immediate neighbourhood of the veins of this material, asbestos, iron pyrites and other minerals occur, which are known to be thus developed in various rocks by veins of intensely heated matter iiected into them in a state of fusion. At Meriwethers bridge and in many other local- ities along the range, the greenish blue rock is studded with black and greenish spots, indicating an incipient crystallization, and clearly referable as the geologist would at once perceive, to the agency of which we have spoken. Here, as well as in all places where similar evidences of igneous action can be traced, the dip of the rock be- comes confused in consequence of the occurrence of numerous cross joints, snch as are often produced in stratified rocks by an action of this nature.

The grey and yellowish red sandstone, occurring in beds some- times of considerable breadth, and traversing the country in the gen- eral range of rocks to a considerable distance, are found in many places to furnish quarries of very valuable building material. Such of these beds as are intersected by frequent veins of quartz, ai'e found to be by far the hardest and most valuable. In the same bed, examined at points some distance asunder, a great ditVerence in the hardness and consequent value of the material, may frequently be observed. Thus, the bed which on the eastern flank of Peter's moun- tain, near Gordonsville, yields a building stone which comes from the quarry in long quadrangular blocks of great hardness and dura- bility, presents at the distance of several miles to the south a crum- bling mass, whose value consists in its being useful as a substitute for sand, or ftimishing a good material for the manufacture of fire bricks. It may, therefore, be found a guide of some value in the selection of rock for flags or building purposes, to choose such as, lying in the vicinity of a heavy vein of quartz, and intersected by smaller ones throughout its substance, is likely to possess the com- bined advantages of great hardness and durability, and a compara- tive facility in being quarried, in virtue of the cross joints by which it most generally and spontaneously divides itself.

In addition to the rocks here described as occurring particularly in tlie South-west mountain and its vicinity, various others are pre- sented both to the south and north of the localities to which the profile may be considered as referring. Thus, in Orange and in Nelson and Amherst counties, as well as in the neighbourhood of Scottsville, in Albermarle, and interruptedly in many other places in the same general range, a very interesting rock is seen, consisting of fragments sometimes angular, sometimes more or less water- worn, cemented together by particles of sand, and occasionally a snuill admixture of carbonate of lime. This singular conglomerate lias evidently been in part derived from the greenish blue rock pre- viously described, with which its larger pebbles or fragments are

obviouslj identical — and in part from the sandstones and occasionallj the limestones of this region. It is in fact the representative, in this portion of the state, of the Potomac marble, and some of it when polished would present a surface of equal varietj and beauty. The occurrence of this rock, as here described, obvionslj marks an epoch of violent action, in which the neighbouring strata, of which it maj be considered as embodjing the ruins, were broken into fragments, and these subjected for some time to the rounding agency of water, at tlie bottom of which the coarser and the finer sediments were at length consolidated into rock. A curious fact, for the first time ob- served by my brother. Professor H. D. Rogers, would seem to show, that iu the composition of the Potomac marble, fragments of limestone may be seen, referable to no nearer source than the great valley west of the Blue Kidge. In some of the columns in the senate chamber at Washington, which by their beautiful polish en- able the observer as it were to look into many of the rooky frag- ments of which they are composed, he detected distinct impressions of Encrini, a fossil remain abounding in the bed of limeatone near the wes<tem flank of the Blue Ridge, and for which we might in vain look in the limestone previoutly described as skirting the east- ern flank of the South-west mountain. This curious discovery will at once indicate the extent of the violent agencies preceding the formation of this rock, and of the conglomerate wnich we have regarded as its equivalent.

In the same region likewise, beds of genuine red sandstone occur, sometimes of a flne and sometimes of a very coarse grain. This and a variety of red slate are the chief rocks to be met with between Warminster and the Folly. Similar beds are to be seen in many places in Orange and other counties in corresponding positions. In Amherst near the Stonewall mills, strata of coarse conglomerate occur, in which the pebbles have sometimes a diameter of half an inch.

Near Lynchburg, a very beautiful bluish grey sandstone is largely quarried, and in the same neighbourhood very extensive exposures of various sedimentary rocks may be seen. In nearly all the locali- ties which have been described, the dip of the rocks is east. At the latter place, however, a very superb exposure of a siliceous and talcose schist is presented on the river bank immediately opposite the town, exhibiting the feature so strikingly seen among the sand- stones of the North mountain — that of an arch or great bend in the strata, showing the eastern and western dips at its opposite extremi- ties.

On the western declivity of the Green mountain, beds of steatitio rock occur, furnishing a soapstone which in all respects compares advantageously with tliat now generally in use. A quarry of this rock has been opened near the residence of Tucker Coles, esq. from which slabs and jambs for fireplaces have been procured. The colour of this rock is of a greyish and sometimes greenish blue, with a somewhat marbled appearance. Its texture is fine, and with suffi- cient firmness for any purpose to which it may be applied. It is

capable of being cat and planed with great facility. With the ex- ception of some of the finer kinds quarried in Vermont, there is probably no soapstone used in this country which combines the yalnable characteristics of this species of rock in a higher degree. The recent introduction of anthracite as a fuel in some of our cities, and the probability that ere long the semi-bituminous and anthra- cite coals of the western ridges of our valley will also bo similarly applied, impart additional interest to the facts here stated, and render it highly probable that this rock will at no remote day be brongbt into extensive use. In the same neighbourliood are found sandstones and schists, all preserving the same general direction and dipping to the east.

Throughout the South-west mountain and its prolongations, but especially on the Buffaloe ridge, micaceous and magnetic iron ore occur. In the neighbourhood of Stonewall mills, and near tlie Buf- faloe ridge spring, these ores are peculiarly abundant. They are also met with largely in the vicinity of the Folly. Hematite con- taining some manganese is seen also apparently in veins in a slaty rock at Reuben Garvers, near the above named mills, and has been supposed by some to be an ore of silver. The micaceous oxide is generally blended more or lens intimately with the substance of a talcose and siliceous schist, and appears to exist in beds of consid- erable breadth amid these rocks. Hitherto, little value appears to have been attached to the magnetic oxide or oxidulated iron ore which is thus abundant throughout this region ; and yet, judging by the experience of other countries where this ore is smelted in great quantities, there can be but little doubt that under a judicious sys- tem of operating it might be found a highly valuable material for the manufacture of iron. In the highlands of New Jersey, so noted for the quality and amount of their forged as well as cast iron, an ore of precisely the same character is used, and the difficulties in smelting, which appear to have deterred our iron masters from its employment, u"e completely overcame.

In many places, within the belt of which we are now treating, beds of rock occur, containing green carbonate, sometimes associ- ated with a little sulphuret of copper. At the Folly in Amherst, numerous openings may be seen from which the cupreous rock was formerly obtained. The amount of copper present in such of the specimens from this locality as have been examined, though consid- erable, is not such as promises any high degree of value in the mass. It is, however, to be remarked, that no positive opinion on this subject can be formed without much minute examination of all the places in which this rock exists, as well as a number of analyses to determine the proportion of copper which it contains. No dis- tinct vein or bed of copper ore is indicated, but rather an impregna- tion of the talcose rock of the neighbourhood, more or less strongly with the above mentioned compounds of that metal. In some of these places the manufacture of copper has been attempted, but without the success that would justify a prosecution of the enter- prise. In Orange, Taylors copper mine, though opened with high

expectation of profit, has been long abandoned. In the neighbour- hood of the Folly, judging from the number and extent of the excii- vations which are seen, we would be led to infer that at the time when they were made great value was attached to the material which they furnished ; and if tbe traditions of the country in regard to the operations of Colonel Chissel in this region prior to the revolu- tionary war, may be received as authentic, that singular and mys- terious personage found in the products of these mines or pits a rich reward for all the labour and expense which he appears to have be- stowed in working them. It would seem that the cupreous rock was not smelted by him, but merely ground in a mill, some vestiges of which still remain, and then packed up and sent to England.

Similar bands of cupreous rock occur in Campbell county on Beaver creek, about two miles from Ross's furnace, and also in the liwer end of the county. Pits like those at tbe Folly have likewise been opened on the land of Mr. Walker, near the James river in Buckingham.

Among other interesting minerals occurring in this region are beds of chloritic steatite tmd chlorite slate near the Variety mills, Nelson county; galena or sulphuret of lead in veins; in quartz at Rennet-bag creek, Franklin county ; sulphate of baryta in numer- ous localities; sulphuret of iron in cubical and other forms, very frequent; plumbago in considerable masses in Buckingham and Amherst; brown oxide of titanium in the neighbourhood of Lynch- burg.

Many parts of the region of which we have been speaking, as for instance in the vicinity of Lynchburg, the Butfaloe ridge and the Folly, are likely to form highly interesting localities to the mineral- ogist, from the variety and character of the minerals they furnish ; and there is little doubt that interesting developments, in a practical as well as scientific point of view, will result from the minute ex- ploration of these and other districts throughout this portion of the state.

What has now been said in relation to the rocks of the South- west mountain and its finnks, will with but little modification l>e found ap])licable in a general way to the rocks of the Blue Ridge and the intervening country. Beds of dark green rock containing hornblende, are occasionally presented. Slates, schists, sandstones and coarse conglomerates, sometimes but little changed, at otliers modified in various degrees, succeed each other as we travel west. From the South-west mountain, and even in the Blue Ridge, the beds of rock exhibit the same features and the same general dip to the east. In the Ragged mountain the rock usually occurring is a coarse conglomerate or sandstone containing mica, and more or less modified, so as to exhibit a structure partly crystalline. In a direc- tion northwest from Charlottesville, a conglomerate containing large pebbles of angular quartz occurs, and in the same vicinity fine- grained yellowish sandstone.

Most of these rocks contain a large proportion of feldspar, so as in some cases when disintegrated, to have many of the characters of

ft kaoHn. A bed of this species exposed near the University, has been found bj Professor Emmet to furnish a material susceptible of varioas useful applications. When baked at a very high tempera- ture, this rock may be made into hones of a very fine and sharp texture. It admits of being readily carved or turned into cruci- bles and other useful implements, for which it is well fitted, by its power of withstanding heat; and for the same reason it forms a very valuable fire brick.

With the view of illustrating the structure of the Blue Ridge the following descriptive list is presented of the rocks which occur at Turks gap, beginning at the western, and proceeding to the east- em base of the mountain. A series of beds in the main analogous to those about to be described, may be observed at Rockfish and Brown*s gap, and other points which have been examined in the course of the reconnoissanoe.

In the profile all these rocks are exhibited dipping steeply to the east, which is their position as observed at Turks gap. But at Balcony falls, where the exposure of rock is extremely grand and interesting, the beds on the western flank of the ridge are seen dip- ping west; east of this they are seen rolling and arching in a manner to indicate violent disturbing action, and at length they assume the ordinary eastern dip. At this place the sandstones of the western base form beds of great thickness. They are for the most part greyish, but some layers of a dark brown colour may be seen among them.

EOCKB OF THE BlUE RiDOB OOMMRlfCiya AT THE WESTERN BaSE

AT Turk's Gap.

1. A light grey moderately fine-grained sandstone, met with near the base of the gap, and extends up a third of the way to the top. Dip steep to the S. £.

2. A finer closer-grained rather bluish variety of the same, overr lying the former,

8. A lead coloured argillaceous slate, slightly talcose, occupying another third of the western side of the mountain.

4. A dark purplish grey and extremely close- textured indurated sandstone, bearing evident marks of igneous action. This bed is not thick.

5. A schistose grey sandstone, rather argillaceous, with minute specks of black sand, and little grains, the size of a pea of transpar- ent amethystine quartz.

6. A greenish grey chloritic looking schistose sandstone.

7. A fine-grained dark bluish green argillaceous sandstone, full of incipient crystallization in small vitreous specks, the size of mus- tard seed. These specks are small amygdnls, tlie exterior being a semi-transparent yellowish green matter like quartz, the centre be- ing black and granular.

8. An argillaceous sandstone like the former, but containing more crystalline specks, some of which are of an opaque pinkish white.

9. Like the two former, the specks being better developed some of these green and transparent, others pinkish white, looking like analcime.

10. A very coarse, extremely hard sandstone, ronnd grains of semi-transparent quartz in a coarse argillo-siliceons paste, evidently much indurated.

11. A coarse-grained purple sandstone; the rounded gravel of pink or amethyst coloured quartz, united by a dark paste.

12. A grey purplish porphyritio looking conglomerate, of very heterogeneous composition, green, red, white, etc., sotue feldspar, much quartz, and to appearance the matter of the green sandstones of the ridge.

18. A similar compound approaching to a brick red, angular pebbles of feldspar and roundeil ones of quartz, etc., in a deep red paste. The four last specimens belong to the S. £. slope of the ridge.

14. A white, rather loose and coarse sandstone, the grains united chiefly by feldspar.

15. A coarse sandstone, with rather angular pebbles of quartz and feldspar scattered through a paste very similar to the mass of a greenish chloritlc sandstone.

16. A very light lemon green epidotic sandstone, with small specks of quartz and veins or patches of asbestos.

17. A very heterogeneous conglomerate, in aspect somewhat like the Potomac marble, and identical with the conglomerate before described as occurring in the vicinity of the S. W. mountain, etc., the larger pebbles identical with No. 6.

18. A compact, close-grained purplish grey sandstone, greatly altered, having kernels of epidote, and quartz, and deep red blotches, making it look like heliotrope.

19. Similar to 7, but destitute of the specks.

20. At the eastern base of the ridge, slaty sandstones of a grey colour.

In presenting the above account of the series of rocks in this portion of the Blue Ridge, I do not wish it to be inferred, that pre- cisely the same beds in the same order will everywhere be found. Observation has shown, that in different part's of the range, the rocks vary somewhat in their character, that while in some places the sandstones are greatly indurated, and filled with various miner- als apparently developed by intense heat ; in others they are com- paratively unaltered, though in all the localities yet visited, some of the beds exhibit great induration from this cause. We are, however, to take tliis descriptive list as representing the important peculiari- ties of the rocks of the Blue Ridge, and we have preferred thus de- scribing them in some detail in the order in which they occur, to attempting to name them according to any supposed or fancied anal- ogies they may bear to rocks, which are found in the old world. Such analogies are very vague, and in this as in many other instances in the geology of our country, are calculated to give permanency to error and check a proper spirit of investigation. In the true spirit

of his science, the enlightened geologist has learned to distrust the generalizations which would always seek analogues to the rocks of one side of the glohe, in those of the other, and will, therefore, pre- fer a description of the object itself to any appellation to which from its supposed resemblances it might be thought entitled.

From the list above given, it will at once appear, that there is no material difference between the rocks of the Blue Ridge and those of the South-west mountain and the intervening country, and that they seem in the main to be distinctly referable to a sediment- ary origin.

From the above view of the general structure of the ridge, we may derive a suggestion of some importance in connection with plans of internal improvement projected in the state, which is, that the dense and impracticable character of many of tlie rocks above de- scribed,— for instance, those from six to twelve, — forbids any attempt at tunnelling the mountain, at least in those places which have been examined, and evinces the necessity, whenever such a p)an shall be proposed in reference to other parts of the ridge, of first ascertain- ing whether it does not there also include near its axis materials equally unfavourable to operations of this kind.*

The soils of the region from the Blue Ridge, east as far as the limeetone, are in many places of a deep red or chocolate colour, while in others they present either a greyish or yellowish hue. Those of the former kmd are usually regarded as most fertile, and chiefly give value to the lands of Albemarle, Amherst, and other counties in this part of the state. In accounting for these striking peculiarities of colour and agricultural properties of the soils in question, it has been usual to regard them as resulting from the hornblende, frequently met with in the rocks of this region, which by its iron would give colour, and by its lime impait fertility to the land. There is, however, but a small portion of this deeply coloured soil traceable to a decomposing rock of the description mentioned, and by far the largest part of the land thus tinged has been produced by the disintegration of the dark greenish blue sandstone, such as occurs so abundantly in the Sonth-weet mountain. Much of the richest and darkest red soil of Amherst and Albemarle has no hornblende in its neighbourhood, while beneath and miugled with the soil, fragments of the sandstone above referred to, may be seen in all the grada- tions of condition, from the hard greenish rock recently separated from the mass, to the. crumbling half-earthj and deeply reddened lump, ready to be reduced by the next winter's frost into produc- tive soil. By analysis recently made, I find that both the green- ish sandstone and the resulting soil, contain a sensible quantity, sometimes two per cent, of lime. Should this be found by further research to be an invariable ingredient of these valuable red soils, we might, perhaps, be authorized in ascribing their productive char- acter, at least in part, to its presence; and we would to a certain

The caution here advised was observed in Beleoting a place for the tunnel sinco coivtnicted at Rockfi:>h sap, and yet great obstacles were encountered OIK iDg to the nature of the rocks. — Ed.

extent be enabled to compare these soils with one another in agri- cnltural vidue, bj cbemicallj examining them for lime.

Portions of the red soil in Nelson and Amherst, arising from the decomposition of a red sandstone and conglomerate befure described, contain lime in a still more considerable proportion. The rocks from which they are procured, in some instances, present npwards of six per cent, of carbonate of lime. A specimen recently examined, yielded me in one hundred grains, precisely 6.75 grains of this substance.

Op the Valley op Virginia.

The sectional line crossing this region, to which the profile re- fers, commences at a distance of two or three miles from the west- ern base of the Blue Ridge, this being the position at which the rocks of the valley first become apparent. Of the character of the beds comprised in this interval we have no data enabling us to speak with certainty, inasmach as the fragments of sandstone derived from the broken strata of that range, piled apon the subjacent beds of the valley, entirely conceal tliem from observation. At other points along the eastern edge of the valley, the interval thus hidden from examination is not so wide, but in no place hitherto observed have the rocks of the valley and those of the Blue Kidge been seen in contact. This, as yet, undetermined ground, is therefore represent- ed on the profile by a blank, at the western boundary of which the valley rocks where first observed, are represented as commencing. Future observations throughout this curious district are indispensa- ble to on understanding of the true relation existing between the formations bounding it on either side, and will accordingly present subjects of geological, and even of practical interest in the prosecu- tion of more detailed research.

As the profile indicates, beds of slate and limestone, in alternate order and dipping almost uniformly to the east, occupy nearly all the space west from this to the commencement of the sandstones of the ridges subordinate to the North mountain. Layers of a very siliceous limestone, and bands of sandstone, occasionally occur. Be- tween Harper's Ferry and Winchester, two alternations of tlie'slate and limestone may be observed ; the most eastern bed, composed of slate, dipping east at an angle of 30° into the valley of the Shenan- doah, succeeded by a broad range of limestone of a dark blue as- pect, and but little veined, dipping in the same direction, next to which is another bed of slate followed by one of limestone, both dipping OS before.

Approaching the northern extremity of the Massanutten moun- tain, the belt of limestone presents interesting peculiarities, some of which may with great probability be referred to the proximity of that lofty range. It is here traversed by large veins of calcareous spar, in general running across the direction of the edges at a con- siderable angle, and it is thrown off from the fiank of the mountain with a reversed or western dip. The veined condition of the rock distinctly pointing to a period during which it was subjected to vio-

lent actioDis cleaving it into conntless fissnres, subsequently filled bj infiltration with the pure material of the rock, taken in connection with its inverted dip along the raonntain flank, gives great proba- bility to the idea that the upheave of this range took place subse- quently to the formation of the rocks of the valley, and that thus tne fissured structure and changed direction of the adjacent rocks, were merely consequences of the elevation of this enormous mass. In connection with this curious point of inauiry, the investigation of the materials and structure prevailing in the Massanutten moun- tain, cannot ful to prove interesting to the geology of the state. Such an examination, moreover, promises more than any other to reveal the geological relations of the valley with the regions bound- ing it on either side, and thus to solve some of the most curious problems with which the student of our geology at present cannot fail to be embarrassed.

In the valleys of this mountain slates and limestones occur, and rumour intimates that eoal even has been found. Beds of a coarse conglomerate, of very peculiar structure, constitute an important portion of itfl mass, and furnish the material of mill-stones now much in use. Limestone is said to occur on the summit of the Peaked mountain, a part of the Massantttten, and it is not improbably the fact.

Should coal ever be discovered in this region, it will probably be anthracite ; and certainly the character of the rocks of the Massa- nutten, so far as they have yet been examined, is not adrerse, if it be not favourable, to the opinion that the search for this mineral might be attended with success.

In passing some distance south and west of Strasburg, the strata resume their former eastern dip, having here apparently been too remote from the mountain, to experience much violent dislocation or change of direction when it arose.

In the counties of Rockingham, Augusta and Rockbridge, lime- stone and slate alternate as before; the former in some places pnssing into veined varieties, and occasionally presenting bands and beds of marble of a good quality. A roll in the strata, or some change and irregularity in the dip, will usually be found to attend tlie veined or marbled varieties of the limestone, and may be looked upon as a use- ful guide in the search for quarries of the ornamental rock. A bed or beds of hydraulic limestone runs along the valley, not far from its eastern side, to an extent not yet determined. In the neighbourhood of Shepherdstown, this rock has been quarried, and found highly valuable in the formation of water cement. A similar limestone appears on the North river, about nine miles from the Balcony falls, and at some intermediate points, but as yet no analysis has been made of the rocks from these localities, and but imperfect trials have been made of the lime obtained from them. It would appear that a limestone of analogous character is found also in Botetourt county, and even further south.

An analysis of the hydraulic limestone from the neighbourhood of Shepherdstown, shows it to contain nearly a third its weight of

alumina, while the ooramon limestone of the vicinity, and indeed of the Valley generally, contains hut a small proportion of this earth. A mere analysis, however, is not always snfficient to determine the value of the material for the purposes of a cement ; and should there- fore, be accompanied with direct trials calculated to test its qualities in this respect. Attention is only beginning to be directed to this sub- ject, which is one to which, from the character of some of our great works of improvement, a minute geological and chemical investiga- tion might be very beneficially directed.

It is curious to remark, that in Pennsylvania and New Jertey, limestone of this description occurs in precisely the same relation to the otber rocks as in the region we are now describing; and from its well known and fairly tested value, as employed in those states, we may look with confidence to the early discovery of valuable beds of it in numerous parts of the corresponding region in Vir- ginia. Fortunately for its use too, the anthracite of the North mountain is of that description of coal which lias been fonnd by far the most suitable fuel in preparing it for a cement.

The existence of foml\fer<ms bands in some of the limestones of the Valley is an interesting geological fact, of which no notice appears hitherto to have been taken by those who have profesaed to explore the country with scientific object Near Strasburg, on Cedar creek, and other points around, the rock displays great num- bers of impressions of encrini, &c., and some trilobites. At Mount Meridian mills, in Rockingham, organic limestone likewise occurs, and what is most remarkable as having hitherto escaped attention, the limestone of Weyers cave and the vicinity occasionally exhibits similar impressions of a very interesting and peculiar character. Further west, in the neighbourhood of Mossy creek, fossils occur in a more siliceous variety of limestone, and I have in my possession a fine specimen of fucus from this locality. Such bands of fossilifer- ous rock seem to be of more frequent occurrence farther south, and are quite common in Botetourt and Montgomery counties.

The importance of the valley limestones as furnishing a power- ful lime for agricultural and various other uses, cannot be too highly appreciated ; indeed, it is rather matter of surprise, that the agricul- ture of this region has hitherto been suffered to reap so little general benefit from this great source of improvement completely within its reach. As yet the application of lime to the lands in this part of the state is in a great degree restricted to particular neighbourhoods, while (in many extensive districts) through the want of experience, and of knowledge respecting its employment elsewhere, the efil- cacy of lime as a manure, is regarded with a degree of doubt some- times amounting to entire disbelief. An impression that the soils of this country are already sufiiciently impregnated with calcareous matter, in consequence of the ])roximity of the limestone rock which occasionally rises to the surface in the fields, seems more than any other circumstance, to have led to the erroneous notion that lime could be of no benefit to the soil. It must tlierefore be regarded as a fact likely to affect the opinions and practice of persons entertain-

log tliese views that in a great many cases, the soils of the valley contain little or no calcareous matter, even when taken from the immediate vicinity of a limestone rock — a fact which has ulso been observed by my brother and myself, in regard to many of the soils in the corresponding region in Pennsylvania and New Jersey. In the valley of the former state lime has long been in extensive use, and is well known to have been the means of imparting rich pro- dactiveneas to many wide districts in the limestone country which were formerly regarded as of little value, while in the small belt of corresponding character in New Jersey, a soil of almost sterile worthlessness has by the same means been imbued with an extraor- dinary degree of fertility. Experience thus ample and satisfac- ttry, under circumstances which can leave no doubt as to the ap- plicability of the results to the valley of our own state, will, it may be confidently hoped, impress our farmers in that region universally with the importance of availing themselves of the invaluable resource which is everywhere spread around them, and of thus removing the impatation of indifference to improved modes of agriculture, which the active enterprise of other regions has already proved to be of great and permanent advantage.

The value of the limastones of our valley, with a view to this most important of all their applications, may be judged of by the rults of several analyses recently made, from which it appears, that in most cases, the carbonate of lime exceeds 80 per cent., and in some is largely over 90 per cent, of the whole mass. A series of analytics, giving the composition of all the varieties of the rock in numerous localities in each county through the valley, would sub- serve one of the important interests of this region, by enabling the farmers to infer what ought to be the proportion of pure lime pres- ent in the product of the kiln in each locality.

Another valuable material hitherto neglected in this region is the Travertine or deposit marl which exists in some places in large qurintities. In Jefferson and Frederick, this chalky deposit forms beds of considerable thickness, mingled with but little extraneous matter. In Rockbridge, nearly all the streams that empty into the South river, flow over a material of the same nature ; and in fact no extensive district of the valley will be found wanting in this deposit. It is in truth a precipitation of the calcareous matter from the limestone waters, which are universal throughout this region, and must therefore be looked for as occurring in most neighbour* hoods where springs thus impregnated are of general occurrence. Now, it is important to be known, that from this substance a lime of very superior quality may be made, and that judging by the value attached in the market to that from the travertine of Cale- donia in New York, the burning of this material in some of oar localities might be attended with very considerable profit; at all events, its utility in agriculture added to the facility with which in some places the deposit may be obtained (no quarrying being neces- sary to separate it from the mass), would render it an advantageous substitute for the limestme of the same neighbourhood. Jiiore-

over, it should be remembered, that in the more friable or powdery state in which mnch of it is found, it may, as in Europe, be verj beneficially applied as a marl without being burnt. The immense improvement which eastern Virginia has derived and is now re- ceiving from the calcareous manures, must render any illustration of the effects of this substance altogether superfluous, when it is understood that in composition it cannot be distinguished from the better qualities of the pulverulent marls, of which analyses have been given in the early part of this report. Independent of which, its value has been unequivocally tested in other countries, where it has been found to have the most decided ameliorating effects npon land to which it is properly applied.

From what has been said respecting many of the soils of the valley, it is not to be inferred that they are all devoid of calcareous matter, or indeed that thit* ingredient is not very often present in some proportion, but rather that in few or no instances does it exist in the soil to such an extent as to interfere with the advantageous application of lime or unbumt calcareous manures ; and under these views, I would urge upon those who are particularly interested in the success of agriculture in the valley, the benefits to be anticipated from the diligent use of the various resources so abundant and ac- cessible throughout this portion of the state.

The iron are of the valley constitutes another of its most valuable possessions. This, although manufactured into iron in numerous places, has as yet been the subject of no systematic geologicil and chemical examination, further than the mere determination of its general features, and some of its qualities in the furnace. An ex- amination of the composition of all the principal varieties now in use, as well as the determination of the relations of the deposit geologically with the rocks among which it is found, would furnish matters of enquiry, whose practical bearing upon a valuable branch of industry in this region, will be promptly and fully recognized by all who are interested in its success. For, although the tact of the operator, in this as in almost every department of the arts, is neces- sary to the profitable pursuit of the manufacture, those engaged in the smelting of iron have long been sensible, at least in other countries, of the high importance of such suggestions as are fur- nished by a chemical examination of the ores upon whicli they operate, and a geological investigation of the positions in which the beds of ore occur. The ores almost exclusively in use are hematites of various aspects, known under the names of Honeycomb and Pipe ores — many of which yield a metal of the very finest character. The facility of smelting, as well as the quality and amount of prod- uct, varies of course with the description of ore employed — and from the want of such knowledge as has been just referred to, the difficulties of the process in some places have almost put a stop to the operations of the furnace.

A new interest attaches to this branch of industry, at least in some portions of the valley, from the recent discovery in the imme- diate neighbourhood of the iron, of beds of a semi-bituminous dry

coal, which, if we may trust to the indications of its oomposition, may hereafter be employed as a most efficient and profitable substi- tute for charcoal in the furnace. Of this coal, as it occurs in the Catawba mountain, and at other points in the valley, but little as yet ia known ; bnt should the hopes excited by analyses wbich I have recently made of specimens from the former locality, prove to be well founded, a new impulse will be given to the iron manu- facture in that district of the state, and rich rewards be proffered to the enterprise of capitalists who engage in it.

Of the various objects interesting to the mineralogist, which are to be foand in this region, but little definite knowledge has yet been attained. 'We may, however, mention carbonate and sulphate of baryta, octahedral and dodecahedral sulphnret of iron, pellucid quartz and crystallized selenite, as occurrmg more or less abundantly in different places. Of the lead ore, gypsum, &c. of the south- west we will speak hereafter.

The numerous extensive caves occurring in this region, form one of its most curious and interesting features, and serve to illustrate some of those geolocol and chemical agencies to which allusion has been made in explaining certain facts connected with formations in other parts of the state. Thus, in the rich and variegated crys- talline deposits and concretions, which render some of the caves objects of so much curiosity to the visitor — the solvent action of watr upon the various kinds of rocks composed of carbonate of lime, and the ready tendency of the dissolved matter to separate in a pure and crystallized condition, are both beautifully displaye<l, nhile the rounded surfaces of the rocks within the caves, and the generally curved contour of the various apartments, give evidence of the wearing, as well as the dissolving energy of subterranean streams. Usually some duturbance of the rocky strata will be seen in and around these caves ; and in the various fissures and deep clefts naturally accompanying such dislocations of the strata, we are furnished with a ready explanation of the means by which the agent that has thus scooped them out originally obtained access to the surface of the rock.

Of the North Mountain and Alleghany Region.

The numerous ranges of mountains which lie beyond the general limits of the valley, present several features of great practical, as well as scientific interest. In the profile view, a section of the Little North mountain, as presented west of Mossy creek in Rockingham, terminates the line of observation first examined ; and the profile is resumed at a point farther south, in a direction from Covington across the Great North mountain into Rockbridge. The lesser ranges of mountains which first interrupt the general undulating surface of the valley, known by the various names of Little North mountain, Catawba mountain, &c., indicate the commencement of a series of rocks entirely distinct from those occurring in the val- lev, being composed of sandstones and conglomerates, and of shales

snbordinate to the veins of anthracite and fiemi-bitaminoaa ooal, which here discover themselves. The dip of these, so far as ob- served during the reconnoissance, is somewhat steeply west, as rep- resented in the profile. A similar direction of the strata is also seen in the range of the North mountain in Rockbridge and else- where, but as exhibited in the section of Browns ridge and the Mill mountain, the dip is east. The rocks composing the North mountain at the place represented in the section, are chiefly sandstones of different hues and textures, with a reddish shale appearing towards the eastern base. Ascending by the eastern side, after passing these shales, we meet with red and grey sandstones ; then deep red sand- stone with occasional seams of shale interposed, to near the summit, where we find a heavy stratum of white pinkish sandstone exposing an extensive bared surface, which dips N. W. On the western side following the winding of tlie spurs, the pinkish variety of rock is succeeded by grey, and thence tracing the mountain to its baso, the red and grey varieties appear with changing dip, sucli as would be explained by the structure indicated in the profile view of this side of the mountain. Pursuing a western course, we find slate dipping to the west for some distance from the flank of the mountain, but assuming an eastern dip as we approach the base of Browns ridge, where a bed of limestone, with a corresponding dip occurs, after which wo come npon the grey and reddish sandstones composing that ridge, which also dip in the same direction.

There being no reason for doubting the identity of the rocks in the North mountain and Browns ridge, we are led to infer, that immediately at the base of the former there exists a western dipping limestone similar to that with eastern dip at the base of the ridge, but not having detected it in consequence of its being concealed by the fragments of rock collected there, it is not indicated in the figure. The series of rocks thus far, commencing with that which in the horizontal disposition, must have been the lowest, would therefore, be sandstone, limestone, slate; and this order we shall find nre- vailin; for some distance further west. The sandstones of Mill mountain, like those of Browns ridge, dip ea)t, and are separated from the former by an intervening valley of slate, the western por- tion of which is seen dipping in conformity with the rocks of the Mill mountain, but in the eastern part no rocks in situ conld be seen on account of the mass of fragments by which they were covered up. From the precipitous escarpments of the two ridges here de- scribed, the apparent identity of those rocks of which they consist, and other striking circumstances in the features of the valley, there can be but little doubt that lines of fault, giving to the strata of sandstone, limestone and slate, originally horizontal, an echelon . position, have occasioned this repetition of the rocks of the ridge in the Mill mountain, preserving their dip in the same direction ; or more familiarly speaking, these two ridges were thrown up from their horizontal position under such an action of the dislocating force as not to elevate tlie rock on the western side of each ; and therefore not to present any strata having a counter or western dip.

To present tliis principle, which is familiar to geolojrists, in another l>oint of view, the rocks of the Mill, Brown, and North mountains, heing rocks of sediment, and having, therefore, heen originally hori- zontal, or nearly so, formed one oontinaons hed, the sandstone lying beneath, the limestone next, and the slate npon the surface, llie disturbing force throwing np the sandstones of the North mountain, gave them a western dip, while other forces dislocating the strata to the west, gave them the parallel but not continuous positions which they now display. Instances of this kind of dis- turbance are among the most usual in geology, and would readily he inferred by those versed in the subject to have occurred at the points here described, by a simple view of the profile itself.

But it is thought that the explanation above given will aid the general reader, for whom the report is chiefly intended, in under- standing the delineation of this portion of our line. West of the mountain to near the hase of the Warm Spring mountain, we pass over slates occasionally exposing the subjacent bed of lime stone, bnt throughout this vaUey scarcely a glimpse of the sandstone which lies still lower can be had. At Bratton's ridge, the limestone comes boldly ont with an eastern dip, and at some distance beyond, a turn not delineated having occurred in the strata, the slate is seen dipping in the opposite direction. This brings us to the little valley of tbe Millboro 8ulphur spring, which here issues from the pyritous slate — and now the slate is found dipping to the east until another change brings np the limestone into view near the Blowing cave, and the dip becomes west again ; after which, with several rolls or undulations as seen in the Cow Pasture hills, it settles into an east- ern dip, which oontinnes to the boundary of the slate near the base of the Warm Spring mountain. Here limestone occurs dipping with the slate, and this brings us npon the debris piled upon the skirts of this lofty range. As the structure of the Warm Spring Viilley will receive an especial notice, I will defer any further de- scription of the profile for the present.

The region to which the portion of the profile just described re- fers, abounds in objects of practical as well as cnrions interest.

The eoala of the Little North mountain, Catawba mountain, &c., are among the most prominent of these in an economical point of view ; and should the reasonable espectations to which their dis- covery has given rise, not be disappointed, will influence in no small degree the prosperity of one of the most extensive and important regions of the state. From the Potomac to the south-western coun- ties, the minor ranges of mountains, rising in general along tlie western boundary of the valley, are known to include beds of this mineral in the various conditions of a pure anthracite, and a com- pound containing variable but never large proportions of bituminous matter, and which may accordingly be denominated semi-bitumi- nous coal. In Berkeley county, on Sleepy creek and elsewhere, openings have been made, from which an anthracite of the very purest character is obtained. In Frederick, Shenandoah, Rocking- ham, Augusta, Botetourt and Montgomery, similar discoveries have

been made; tlic coal of the foar former coiiDties, as far as yet ex- amined, being ne.'irly identical with that in Berkeley, while that found in Botetoart and Montgomery contains a considerable portion of bitnmen, though far less than that of ordinary bituminous coal. The veins which have as yet been examined vary from three to seven feet in thickness. That represented in the profile, dipping west into the Little North mountain, near Coal run, in Rockiugham, is about four feet thick. Several openings at different points in the neighbourhood, present no perceptible variation in the character of the coal, which is a pure anthracite, capable, as experiment has shown, of burning with bnt little flame, and with the production of a very intense heat. At this place, and it would appear also in others in the same range, the coal readily falls into small fragments, exhibiting numerous rubbed and shining surfaces, leading to the impression, which an examination of the enclosing rocks would also indicate, that a dislocation of the strata has occurred, attended with a sliding and grinding action of the roof and floor of tlie veins, breaking up and Assuring the included coal, and occasioning by the mutual attrition of the contiguous surfaces that peculiar lustre and striated appearance which they invariably exhibit. In some of the veins, however, this crushing eflTect appears to hare been but little felt, and the coal comes from the vein in larger and more perma- nent masses. A further exploration of those veins, in which the coal has been thus reduced, may bring to light other portions of the vein, in which comparatively little of this grinding and crushing action has occurred. For some purposes, this broken condition of the coal would not impair its usefulness but for general sale it would affect its market value.

According to an analysis of the Berkeley coal executed by roy brother, Professor II. D. Rogers, it contains in the one hundred grains only 4.94 grains of grey ash, all the remainder consisting of volatile and combustible matter. Ihis indicates a purity exceeding that of the Pennsylvania anthracite in general, which at a mean contains about six per cent, of ash.

In the eoal from the Catawba, I have found varying proportions of bitumen in the specimens from difierent localities. An average of these results indicates about 14 per cent, of volatile matter, chiefly of a bituminous character. This coal bums with but little intu- mescence or swelling, is not much inclined to cake, has no tendency to splinter when burning, and forms a large amount (upwards of 80 per cent.) of a very superior kind of coke. Allusion has already been made to the probable value of this mineral, in connection with the iron manufacture of this part of the stite ; but further explora- tions of these veins, together with careful chemical analyses of the coal as well as iron ore, and actual trials of the former as to its qualities in the furnace, are yet required, in order to determine with certainty the usefulness of this coal in the raw or uncoked condition, in reference to this branch of industry. In connection with these remarks, and more especially as suggesting an important hint to those who may be endeavouring to bring these dry coals into use in

tbe W&7 alluded tdi, tt tna; here be added, that from Eire {reat bdo- oess acteodiiig the use of tlio hot air hUul in France 'wsA' Krigland, irbere, in some tHiaea, coals in the raw state, of an Bna!bg<ius char- acter, &r employed, the iu trod action of the aaniH nioiie of-opem- tioB here, holds out the promise of moat profitable resnlta"!"! it maj be further suggested, that the great eltjciency and eQonoipj of the kot air, even according to tbe trials made in thia couDtr4.with tiie ordinary materiala used as fael in our fnrnaoes uughl at oq.ee'lo excite th attention and awaken tlie entcrpri of all who are- con- cemed in this highly important branch of our manufattui-ee.

The aandatones, limestones, and slates of this region, nre all.af thero conTertible to useful fiurposea. The pinkish variety of toe . totmer is quarried in the Nortn mountain to furnish liearths fot . furDaoe)>, and has hardness and sharp grit, which has led to its-, empluyment ad a substitute for the more expensive millatones. The - aUte is largely impregnatsil with iron pyrites, and upon exposure to the air yields a great quantity of sulphate of iron or copperas, as well as sulphnCo of alumina or alum.* It is for this reason, that the springs of this part of the state so frequently possosa a a id phu retted, chalybeate, and acid character, and tliat aome of them are so pow- erfuUy remedial in catoneoas and varioos other diseases. The cole- brated alain rock on Jiickson's river, consists of notliing but this sl;ite, which here rises in an abrupt and lofty cliS, forming a semi- circle at the bend of the river, end presenting a scene nhlt'b is at ODce ourious and imposing. Over the surface of the wait-like pre- oipice, streaks and stuiua arising from the copperas or ferrnginons matter of the rock, may everywhere be seen, and large nodnles of a spheroidal form, and of the size of a bomb, lie here and there em- Wdad in the mass. Snch is the smonnt of chalybeate and other laline, as well as of snlpliuroiis matter in these slates, that the in- habitants of the country, in lieu of resorting to the springs, of which some, as the Alum spring are much in vogue, ore accustomed to make use of the detached fragments uf the rock, which in small quantity will impart to water all the flavour and effects of the springs theni'irlvi;!'. Chalybeate and sulphuretted sprioga break forth in varioii-; ili-i's from the pyritons slate above described, many of which, aw tm ample, the Botetourt, Augusta, Rawley, Sbannondale, Yclluu ;iiiil Atom springs, have acquired reputation for their medicinal i ii : 'i '.. Thermal waters abounding in free carbonic acid and nitrogen l' ,— j, roMmbling those of the Warm Spring valley, occur in some 1(ii';.i!:i<'~,

an iutoresting example of which may be seen in the neighbour h i uf

Eayser's in the gorge of the Rich Patch mountain. Analyae& on io relation to the characters of several of these wutem, forbid the publication at present of any decisive results, hut it is hoped, that by nn early day aome aocount of their constitution will bo emboJied in a treatise on the mineral waters of Virginia, now in coarse of preparation.

Of the lime*tone, it m.ty merely be stated, th/it it is capaUit of Tbi word nlum is used iu tlic then common though not nm.— B, K. B.

farDishing, aNime fully eqoal to that of the valley, and that the ex- tent to vvUh it exists in the deep valleys of this region, renders it acces8i)le*tVjr agricultaral purposes on almost every farm. Many heantifuF ftnd fertile spots possessing the advantages here stated, lie eitcr<}9ed among these monnteins, which, with facilities of trans* portation, mnst, at some not distant day, he looked npon as choice plaxK* of the state.

''irfin ores similar to those of the valley, abound on the flanks of tfie* mountains where the lime stone occurs, and many successful furnaces are supplied from this source. At Jordans furnace, near the Mill mountain, castings of a very superior quality are made from /**.a*hematite procured in the neighbourhood of Brushy ridge ; and at no :'/' great distiinoe above, on the Jackson's river, the enormous water power which is here given by the torrent as it makes its way through tho Rich Patch mountain, is in part applied to give action , / to the machinery of a large and successful forge. Facts of this kind, though new to very few, are calculated to iiz our attention npon the great resources in materials and motive power which these wild districts of the mountains possess, and thence to illustrate the pub- lic advantages which are at some future day to flow from the estab- lishment of proper facilities of communication with them, and the direction of wealth and enterprise to the practical developement of the riches which they contain.

Most of the rocks of this region contain numerous fossil impres- sions. The bare sandstones on the summit of the North mountain, seen from the road in passing from Lexington to Covington, display a great profusion of encrini and other zoophytes; and the sand- stones of the Mill mountain, Rich Patch mountain, &c., present similar vestiges of organic life, together with hollow casts and marks of shells. In addition to such traces the surface of these rocks occa- si<mally exposes those waving? ridges which are known to geologists as ripple marih and which are referred by them with almost un- doubted certainty to the same causes as are found at the present day, producing precisely similar markings upon the sandy surface of the ocean beach. Large exposures of the rocky surface, thus beautifully rippled, may be seen in numerous "parts of the North mountain, and the other remoter ranges, and under the above view of the origin of this curious feature of the rocks, are calculated in a beautiful manner to illustrate the circumstances under which the strata of this region were deposited.

The slates, particularly those in the neighbourhood of the coal veins above referred to, present large and perfect impressions of fern leaves and other vegetable remains ; and the limestones are rich in shells and madrepores of various kinds, and often of uncommon size. Fine specimens of Terebratnla and Caryophylle® may often he ob- tained entire.

A curious and imposing feature in the rocky scenery of many

places in this region is the bent or arched arrangement of the strata.

In following the windings of the Jacksons river tbrongh the

wild and picturesque valleys and gorges by which it makes its way

into the more ox>en region towards the east, this strange confor- mation of the rocks is seen in several places, jfiimisfaing in the eta- pendons elevation of the cliffs, and the massive character of the beds of which these arches are composed, the most instructive and mag- nificent iUastrations of some of those agencies to which geologists are accastomed to refer. One of these instances of bent strata, par- ticalarly worthy of observation, is presented in the deep cleft of the Rich Patch mountain, through which the river makes its final escape from the ragged region in which its progress has been previously so much obstructe<1. Looking from Eaysers or the Forge, the naked side of this hnge defile, towering in a nearly vertical wall, washed at its base by the impetnons torrent which flows eastward with a rapid descent, exhibits the grand spectacle of an enormous and almost un- broken arch of sandstone rooks, rising at its extremities in steeply dipping lines, curving with more gentle inclination to its summit, and spanning a distance of several hundred yards. Thin ledges of a very hard variety of the same species of rock project at the abutments of the arch, and rise along the side of the cliffs in a nearly perpendicu- lar direction. On the opposite side the same position of tne rocks is seen ; but here, in many places, the continuity of the arch is broken. A similar scene, though on a smaller scale, is presented in the gorge by which the Calf Pasture river finds a passage through the North mountain ; and indeed it would appear, that this feature in the i)0- aition of the strata, is a common occurrence in all the mountainous ranges of this wild and beautiful region.

Proceeding westward in the profile, we come upon the heavy beds of sandstone of the Warm Spring mountain, dipping rather steeply to the east-~on the western base of which we meet with a foesiltferons limestone, having the same dip, and therefore lying beneath the sandstone. Bounding this valley on the west, tlie Little Warm Spring mountain and its prolongations, exhibit the same rocks in the same relative position, with this important difference, thitt they all dip west* The relation of the rocks thus described, and as they are represented in the section, admits of a simple explanation, by conceiving a violent upthrow to have occurred along the line in which the vley now exists. The sandstones thus thrown off on both sides, left the deep fissure in which the limestones, elevated by the 'same upheaving action, were revealed to observation. In this view, the mountains bounding the valley have been forme<l merely by the forcible protrtfsion on either side of beds of sandstone of enormous thickness, which were originally in a horizontal position — and the limestone, which appears dipping in opposite directions and beneath the mountains, was brought into view by the same agency, although previous to its elevation it must have existed at a depth of nearly 2000 feet below the surface. This valley has, therefore, the character of an enormous fissure, and considering it in that light, we have no difficulty in accounting? for the number of ther mal springs which it oontnins. The well established fact that the temperature of the earth's strata increases with their depth from the surface, in connection with the structure of the valley here described.

will at once explain the elevated teroperatare which all these springs display, while peculiarities in the mineral ingredients of the subja- cent beds, which it may readily be imagined would account for the gases which they evolve, as well as the saline and other ingredients which they hold dissolved.

In connection with these views, it is important to remark, that the fossils and other characters of this limestone distinguish it from those which are found among the mountain chains to the east or west, and that it bears a striking analogy to the fossiliferous luane- stone formerly, described as existing in the great valley of Virginia. Granting the identity of the two, we would thus have the slates and limestones of our valley occupying a position at great depths below the various mountains and valleys we have been describiii, and only appearing at the surface where some great uplifting force has oper- ated, as in the Sweet Spring valley, tossing away the upper and more recent strata.

Throughout all the region of which this portion of the profile may be considered as giving merely a local representation, the ther- mal waters, in virtue of the carbonic acid contained in them, hold in solution large quantities of carbonate of lime. The carbonic acid in quickly escaping from the water by exposure, permits the calca- reous matter to separate, and thus, as the stream proceeds, this in- gredient is precipitated at every step. Hence it is, that we find the channels of the streams thus impregnated, covered with a hard in- crustation, accumulating in tliickneifs every day, and even the stones and twigs over which the current flows, become encased in a film of semi-crystalline calcareous matter. Agitation of the water favour- ing the escape of the solvent carbonic acid, wiH also contribute to the rapidity of this accretion, and accordingly it is found, that where the ripples are numerous, the deposit is comparatively abundant, and what at first view seems most strange, even the ledges over which the streams are precipitated in cascades are themselves built up by additions of the calcareous deposit. The travertine forma- tions of these valleys, produced in the way we have just described, are in some cases of immense thickness and extent. That in the neighbourhood of the Sweet sprin<s, has in all probability, a thick- ness in some places of upwards of 100 feet, and every year adds slowly to its amount. At the Falling spring, nearly on the route from Covington to the Hot springs, a still greater depth of this de- posit has been accumulated, and in various other places throughout this region, masses more or less considerable of the same curious formation, may be met with in the valleys, and sometimes even at considerable elevations on the sides of the hills.

The travertine, like that already alluded to as existing in Jeffer- son, Frederick and other counties in the valley, is capable of being made highly useful in agriculture, and of yielding a lime of the great- est purity and whiteness.

In the mountains west of the point last referred to in the profile, we discover the ternary series of sandstone, limestone and slate, as before described ; the limestones showing themselves altogether on

tbe flanks of the moatitaina, and then only occasionally peeping forth. As represented in the profile, repeated alternations in the dip of the strata occur in this region, and the structure of tbe ridges is generally such as to present a dip ontwards on both their eastern and western sides. Progressing westwards, the overlying slate is increased in thickness by the addition of other, and not exactly similar beds, over which, and generally dipping to the west, we find the samlstones and slates on the western fiank of the Alleghany moun- tains as presented in the neighbourhood of tbe White Sulphur springs. Among the numerous ranges of similar structure to that exhibited in the profile, and which are usually denoted by the common name of Alleghany, veins of coal have been discovered in many places, and tbe black shale usually accompanying this mineral is of frequent occurrence. One of these veins is exhibited on the profile, as seen in the vicinity of Crowe's near the base of the Sweet Spring monn- t2un. A similar vein about three miles north of Lewisburg, fur- nishes a coal which, according to the trials which have been made of it both in smiths' forges and in ordinary grates, has been shown to be of good quality. Most, if not all of these coals, are of the semi-bitnminous character, and are, therefore, not much prone to cake while burning.

Bands of fossiliferous slate and sandstone are exposed to view in many places among tl)e mountain ridges of this region. The hard dark brownish sandstone, generally seen lying in bands of a few inches thickness, is often largely stocked with fossil impressions. A single stroke of tbe hammer will frequently reveal, over an ex- tensive oven surface of the fractured rock, multitudes of such casts, chiefly the joints of Encrini of various species ; and so common is the fossiliferous rock throughout these mountains, that a large pro- portion of the broken masses met with in the channels of the streams and in the numerous dry ravines which form the beds of winter torrents, are rich in curious and instructive fossil traces.

Tlie calcareous matter which once formed so large a portion of these various rocks in the shape of shells and zoophytes, haj* entirely disappeared, leaving hollow moulds, marking the form and character of the fossils which have been dissolved away. Yet so distinctly do these casts preserve all the delicato lines and marks of their originals or seals, that tliey furnish the scientific observer with a snfliciently definite knowledge of their peculiarities to enable him to refer them to their proper places in the arrangements of the nnttiralist, and by comparing them with the fossils of other strata and other regions, to make important infeinces concerning the geological epoch of their existence.

In the limestones of this region fossil impressions are equally abundant. At Callahan's and near Crowe's, the mass of the rock appears chiefly to consist of solid casts of shells, which, with a little care, may frequently be detached entire, exhibiting unimpaired, all the peculiar features of the shells themselves. Perfect specimens of several species of Terebratnla and Productus may be procured at these and numerous other localities; and with a little research, a

rich collection of fossilB may be gatliered in almost any part of tbm region comprising a variety of species unknown in the geology of Europe. Seeing, from the character of these impressions, that tlie living beings whose traces are thus engraved upon the rocks, were once the inhabitants of an ocean, we reflect with wonder upon the curious geological changes which have occurred since the period in which the exuviae of these shell fish and zoophytes were gradually accumulated in the sand and mud at the bottom of the sea, and we look with new interest and astonishment upon the solid texture and towering height of the rocky strata in which these unequivocal traces of oceanic life are thus dumbly impressed.

One of the most valuable of the rocks occurring in this region, is the brownish slate, of which the firm and even surface of our mountain roads is now frequently formed. The existence of this admirable material immediately adjacent to the roads in many parts of this region has already exerted a most happy effect in their con- struction and improvement, and has rendered them for beauty and convenience, deservedly the boast of this portion of the state.

The numerous mineral springs for which this region is so cele- brated, and which, perhaps, constitute its most valuable possession, could not be properly described m the narrow compass of the pres- ent report ; and as injustice might be done by such meagre notices as it would be possible to introduce, a special description of their character and contents, and of the geological features of the sur- rounding conntry, will be reserved for another publication, now in progress, in which such details will be given in all the amplitude they deserve, and from which, should the minute geology of this and other parts of the state be called for by the legislature, all the im- portant particulars bearing upon this point will be borrowed and incorporated in a more detailed report.

Among the general considerations in relation to them, which may with propriety be introduced in this place, it is wortliy of re- mark, that while the thermal springs to which we have referred, in treating of the Warm Spring valley and other places, appear to be indebted for their impregnation chiefly to rocks of a calcareous de- scription, and are accordingly found either in or near such rocks, the sulphuretted springs now referred to, among which are the White, lied, Salt, Blue and Grey sulphur springs, appear to derive most of their ingredients from pyritous slates, and will therefore be observed to rise through or in the neighbourhood of strati of this nature. Of these the White Sulphur is the only one which can be regarded as decidedly thermal, its temperature being about 64% while the others do not vary considerably from the usual tempera- ture of the ordinary springs around them.

Another point of a general character which may be noticed here, is the radical diflference as to saline and gaseous ingredients ob- servable between the springs formerly alluded to, and those of which we now speak. All the waters of the Warm and Hot and Sweet Springs valleys, and several others of analogous character, and highly thermal temperature, discharge considerable quantities

of free gaa, consisting of carbonic acid and nitrogen, of which the latter was first distinctly recognized by myself and found in general to be present in very great proportion.

At the same time a large amount of carbonic acid is held in combination in these waters, imparting the acidulous character for which some of them are remarked, and giving them the power as already mentioned of holding large quantities of carbonate of lime dkisolved. This acid impregnation is in no instance more strikingly manifested than in the waters of the Sweet Spring valley, of which that of the Red spring about a mile below the principal fountain of the Sweet springs, presents an amount of the combined gas equal in volume to aboat one half of that of the water itself.

Another important distinctive feature in the constitution of the class of aprings here spoken of, is the large amount of the earboTutteSy principally that of lime, and the comparatively small proportion of the ntlphata with which they are impregnated.

On the other hand, the class of mlphuretted waters as exemplified in the springs previously named, contain but little carbonic acid, ani a comparatively minute amount of carbonate of lime, or other carbonates, while they are richly fraught with sulphuretted hydrogen gas and Tarious sulphates, of which those of lime and magnesia are present In most considerable proportion. Besides the several points of distinction above referred to, it may be further added that the sulphuretted waters are in general impregnated with various or- ganic matters of very peculiar characters, which by collecting in the reservoirs and channels of the springs, in mixture with precipi- tated sulphur, have, by the various beautiful colours which they impart, given rise to the different appellations by which the more celebrat of these fountains are now known. But while such gen- eral resemblances as have been described, will be found to prevail among the several springs of each class as thus cliaracterise<l, it is at the same time to be remarked that they possess striking individual peculiarities, imparting to each an amount and species of medicinal agency in some degree appropriate to itself.

Viewed simply in relation to the number, variety and high repu- tation of its mineral waters, this region is well entitled to be proud of the vast resources of which it is possessed. Grouped as these springs are at moderate distances apart, presenting within the same district a variety of medicinal character, for which in other conn- tries, regions remote from each other require to be visited in suc- cession, placed at a point equally accessible to the inhabitants of the seaboard and the great valley of the west, and situated in a region of grateful summer temperature of salubrious climate and of pic- turesque and diversified natural beauties, they are now rapidly attain- ing a celebrity for powerful and varied remedial qualities, as well as for the refined social enjoyments which are annually gathered around them, destined ere long to eclipse the older reputation of the famed fountains of the northern states and to vie even with the long established character of the most noted of the watering places of the old world.

Among the valaable minerals of ibis portion of the state, men- tion should be made of the rich iron ores occurring along the ridges in numerous places, and which, from the frequency of coal seams among these mountains will one day be brought into profitable use.

Saltpetre is found mingled with the earth iu many of tlie caves in this region, and has been procured from time to time in consid- erable quantities from this source. Tliis earth or petre-dirt, as it is called, is obviously a sediment deposited from the waters, formerly or at the present time found within the caves, and has sometimes a texture of such impalpable fineness as to indicate tliat the deposition took place while the liquid was in a very quiet state. Besides the saltpetre or nitrate of potash, it also contains a large amount of nitrate of lime, which, by the usual process of mingling the wash- ings of common ashes with those of the petre-dirt, is by a direct chemical action converted into saltpetre. Immense heaps of the earth from which the salt was formerly obtained, may be seen in some of the wide chambers of the Singing and other caves, which tliere is reason to believe, in process of time, will become as rich in this substance as before.

In the same caves Gypsum is also found mingled with the petre- dirt and sometimes enclosing large lumps of it in a thick crystalline envelope. In the Organ cave so much of it is found both in thif condition and replacing the shells originally existing in the slaty limestone, as to make it worthy of enquiry, whether it might be turned to profitable use.

Returning to the profile at the point marking the intersection of Howard creek with the line of observation, we remark the com- mencement of a series of sandstones and slates differing from tliose of the Alleghany, and presenting that want of accordance in the dip which may probably mark the beginning of the groat western series. The rocks of the former kind here exhibit what is called a dicigonal lamination, a structure very general among the sandstones of the west, and one from which tlie geologist derives important hints as to the natural circumstances existing when these strata were de- posited.

On the eastern side of the Greenbrier, is an outlying hill com- posed of horizontal beds of limestone, resting upon red and green friable slate. At several points south of this, in a direction towards the Salt Sulphur springs and Uniontown, this limestone is discov- ered, and in proceeding some distance towards these points, the hills as well as the valleys present scarcely any other rock but a limestone, which, judging by its fossils and other characters, may be regarded as probably the same as that here represcnted. Beyond this point, we meet with west-dipping strata of reddish shale, with a thin band of limestone on the descent of the hill approaching Lewisburg. This brings us into the fine lime stone valley, on the confines of which that town is situated, and here we find the rock dipping at first very gently to the west, then becoming horizontal with slight undulations, covered beyond Tutwiler's with a soft arenaceous rock, approaching to sandstone in appearance, but which

is in reality merely the earthy iDsolnble portion of an impnre lime- stone, from which the calcareous matter has been all dissolved away. Beyond this point, the limestone rises with an eastern dip, in the neighbonrhood of Milligan's creek, after which, at the eastern base of Muddy Creek mountain, it is seen dipping westward beneath and mingled with the strata of soft slate, and again appears on the west- em side of this ridge near its base, coming out with a dip in the opposite direction. Finally, it shows itself capping the remoter part of Brushy Ridge and dipping in a westerly direction, as if prolonged beneath the heavy beds of slate and sandstone of which the Meadow mountain is composed. After this, it is not observed to re-appear in proceeding further west.

Whether as has been supposed, the limestone which has just been traced, is continuous with the extensive beds of this description which are spread over a wide district to the south, forming but a part of one general deposit of which the horizontal limestones in the vicinity of the Salt Sulphur springs and Uniontown, and even of the Red Sulphur, are merely other portions, it would as yet be premature to venture upon deciding. No such identity of fossil and other characters has so far been observed in the rock from these different districts to authorize a generalization of the kind, and it roust be left to minute future investigation to ascertain the true re- lations subsisting between these beds.

The extent of the limestone region south and west of Union, is as yet bat imperfectly ascertained. Passing the Grey Sulphur springs and proceeding to the south-east side of the Peters moun- tain, we find around the base of the AngePs Rest and Salt Pond mountains, and throughout the valley in which Pearisburg is situated, a wide extending stratum of nearly honzontal limestone, much of which along the New river, is remarkable for containing masses of siliceous rock, embedded in its substance, sometimes having the homy aspect and hardness of genuine flints. Most of these frag- ments, however, are irregular in form, and bear a striking resem- blance to the white and very compact sandstone which is seen pro- fusely strewing the flanks of the Peters mountain, for many miles around. In several specimens, I thought I could perceive indis- tinct traces of enorini, such as are frequent in that rock. Possibly, however, these masses may have become entangled iti cavities on the limestone, in which by chemical action they were subsequently cemented.

One of the most curious objects in the particular district of which we have just been treating, is the lake near the summit of the Salt Pond moontain. The erroneous impressions and absurd speculations to which it has given rise, will be accepted as an apol- ogy for the few descriptive remarks which I shall here present. This beautiful sheet of water is situated at the intersection of the Salt Pond mountain and several of its spurs, and not, as is commonly supposed, on the top of the mountain. Its height above the base of the mountain, is probably from 900 to 1000 feet, but it is sur- rounded by steep and lofty hills on every side, excepting that by

which it is approached, and that through whicli its waters find a small outlet, falling in a picturesque cascade of great height, and then flowing rapidly into the creek below. The outlet appears for- merly to have been deeper than at present, and the extent of the lake was therefore much less than it now is. Rocks and earth gradually accumulating at the passage, have dammed the waters up, and hence the trees and shrubs which grew upon its margin, may now be seen sometimes standing erect at a considerable depth beneatii its sur- face. Its length is about three quarters of a mile— its greatest width about half a mile. By careful soundings from side to side, in many parts of it, the greatest depth that c6uld be found was from 56 to 60 feet ; but such was the transparency of the water, that the bottom could be seen nearly in its deepest parts. No animal is found Id it but a small species of salamander or water lizard.

Of the Muth'West portion of the state so little is known, further than the existence and value of its gypsum, lead, salt and iron, that no general views, even of its important geological features, can bo ventured on with safety for the present. Even the tracing of the limits of those formations that connect a portion of it geologically with the great Virginia valley, would as yet be premature ; and of the true character of the more western parts, we have no means at present of forming any accurate opinion. Ilence in introducing the few remarks relating to its structure and economical resources which I shall presently bring for\i'ard, little or no regard will be paid to any imaginary lines of demarkation, which might be conceiv sepa- rating from each other the distinct geological formations which there is but little doubt that it includes.

Through an exclusive attention to the direction of the drainage of the northern and eastern portions of this division of the state — as, for example, in Montgomery county — the designation of Alle- ghany has been very strangely and unphilosophically applied to a comparatively elevated portion of the table lands of that county — and guided by the same principle, in tracing a supposed connected chain which forms the water-shed of both the east and wet-diii- charging rivers, the same title has been applied to a portion of the Blue Ridge, constituting the western boundary of Patrick and Grayson counties. Thus we have the same tenn applied successively to ridges entirely dissimilar in regard to the materials of which they are composed, and the epochs to which they are geologically to be referred; and what is of much more practical importance, mistaken conceptions of the nature and resources of these districts will be al- most certainly suggested, on a first view of them, as delineated upon the map, from the prevailing idea, that a continuous mountain chain, thus bearing a common designation along its entire extent, must of course exhibit great similarity in structure and materials through- out all its parts. Nor is this all : by following the fallacious guide of the direction of the drainage, instead of actually tracing continu- ous ridges, likely to present a general similarity in character through- out, we are in many cases giving an imaginary continuity to elevated portions of land frequently belonging to successive ridges, and thus

creating in iinagination a connected monntain in a direction or di- rections in wliicii none snob actually exists. Hence, iiothing is more common in descriptionB than to hear of the Alleghany poMing under the Petera monntain, near the Sweet springs, traversing the varioui* ridgea to the east until it arrives at Christiansburg, and thence by many crooked courses, tending towards the Blue Ridge, until reach- ing that mountain, it suddenly cuts it off, and bends its own course to the south- west. But during all this description, the speaker is seldom aware that he is describing what, to a great extent has no original* in nature, and that what he represents as one mountain, a continuation of the great Alleghany of the upper and middle portions of the state, here striking across the numerous ridges to the east, and making its way in that direction under and over and through the numerous mountains which seem crowded in a phalanx to resist its course, is, in reality, through much of its extent, only a series of spurs, sometimes merely elevated table lands, dissimilar in structure and origin amongst each other, and only associated in an imaginary connection by the accidental circumstance that they form one portion of the water-shed of the east and west-discharging rivers. A more accurate knowledge of the topography of the state, and more judi- cious principles in the application of terms, will, it is hoped, at some future day, correct this preposterous error in the designation of our mountains, and will substitute on our map such names as the real constitution of ridges of analogous formation throughout, would render natural and appropriate. Thus the western boundary of Patrick and Grayson ought to be called Blue Ridge, and no ridge or mountain east of the Peters mountain can, with the least propriety, be entitled Alleghany.

Op the SotJtn- western District of the State.

In exhibiting a few particulars relating to the mineral structure and resources of the south-rwest, we will confine our attention chiefly to the limestone, lead, gypsum, salt, and coal, which it possesses.

Much of this region is overspread with fossiliferous limestone of various kinds, as well as otlier varieties containing no fossils, and approaching in some places to the character of marble. Semi- bituminous coal is found in several localities, as on Strouble's run, &c., in Montgomery, and in other places in the Brushy and Walkers mountain. Iron ore is also abundant in the same districts.

The lead ares of Wythe, under judicious management in the working, and with favourable means of conveying the resulting metal to the proper market, could not fail to become a large source of profit to the state. In the forms of sulphuret and carbonate, they contain a large per centage of the metal, and require no expensive arrangements for the reduction, the sulphur in the one, and the carbonic acid in tiie other, readily escaping under the application of a heat of moderate intensity. Both of these ores are wrought, although of late it would appear that the carbonate is preferred, on account, it is said, of its yielding a lead of purer quality. The

snlpbnret, as is freqaently the case, contains probably aDtimonj or arsenic, perhaps both, while the carbonate is much more likely to include no other metallic ingredient but the lead. Until lately, the ore of this description, from its eartliy appearance in most cases and its total want of an external metallic aspect, hnd been re- jected as of no value, and it was only by accident that its character was revealed to those who were working in the mines.

The sulphuret or blue ore (Galena) occurs in veins of rotten or chalky limestone ; the carbonate, in beds generally situated at the intersection of the veins. In the extraction of tlie metal'the fuel employed is wood, and the operation is performed in a simple rever- beratory furnace.

The gypsuMy as far as certainly known, occurs over a space about 20 miles in length, and half a mile in breadth, but probably the area actually occupied by it is much more con?iiderable. The depth to which it extends in some places is enormously great. It lies in beds between strata of limestone, slate, and sometimes sandstone, and has to be penetrated for a gieat depth in boring for salt water. In some cases it is siid to have a thickness of nearly 800 feet, iti eluding the bands of rock among which it is stratified. Its condition is either that of a fibrous crystalline mass of nearly perfect purity, or a granular bluish grey and veined rock, containing a small amount of earth, but still as little mingled with extraneous matter as any of the imported plaistcr. This precious material, owing to the difficulty of transportation, is yet unknown at any distance towards the sea- board, but during favorable seasons it is conveyed in arks down the Ilolston, to the south-western states, and in this way yields a hand- some profit. With facilities of transportation, what incalculable benefits might the great valley of Virginia, and much of the region west, as well as east of it, derive from this invaluable deposit, and what an active and productive commerce might it give rise to throughout that region in which it is found!

The Salines constitute another of the treasures of this district of the state. As yet but little has been done, either towards deter- mining the extent of the saliferous strata, or the chemical nature of the various ingredients, hesides the common salt, which the brine holds dissolved. At the salt works on the Holston, the wells are usually from two to three hundred feet in depth, presenting strata of limestone near the surface, sandstone or slate alternating with beds of gypsum several feet in thickness, next beneath, and finally, a stratum of clay, within which the salt water is procured. This clay is of a reddish aspect, and a very argillaceous texture, being in all probability a softened shale, such as that of the brine springs and rock salt of Cheshire in England. In fact, a marked analogy is pre- sented in the structure of the salt region of the Holston, and that of Cheshire. In the latter, beds of gypsum are found alternating with strata of indurated clajs and smids, approaching to slates and sand- stones ; and carbonate of lime exists largely in the strata lying near the surface. In all of these particulars the salt region of the Ilolston corresponds with it very closely.

The great value of the Ohesbire region, however, resolts from the heavy beds of rock salt which it includes, and of the existence of sarh upon the Uolstoo, though far from improbable, no ]>u8itive testitnon V bus as yet been obtained.

The oarions fact, that on some occasions granules or small crys- tals of salt aro brought up by the water of the wells, is certainly very much in favour of the opinion, that such beds of the massive salt do actually exist at depths to which the borings hitherto made have not extended, and furnishes strong additional incentives to a perse- vering and thorough exploration by borings in numerous places penetrating to still greater depths.

The proportion of common salt varies with different wells, and even in the same is not perfectly uniform. In some cases 10 gallons of the brine will yield one gallon of salt, in others 16 are necessary. Taking the specific gravity of salt at about 2.5, and allowing some- thing for the interstices in the dry measure, we would have in the former case a strength of about 20 per cent. Gypsum is always present in tlie brine, and is almost the only impurity in it.

Of the eofU occurring in Montgomery, and other parts of the S.W. region, nothing at present need be added, as the remarks al- ready made in regard to the beds of the same variety of this mineral, occurring in the Catawba mountain and elsewhere, would be equally applicable to those found further south. Iron ore of a very peculiar character is found in Grayson, and Wythe, &c., yielding in some cases, by the usual smelting process, a metal having all the qualities of steel.

The Great Western BrruMnfous Coal and Salt Region.

We come now to treat of that enormous area of nearly horizon- tal strata which we have designated as the fifth great geological sabdivision of Virginia. It comprises, as already shown, the large territory lying between the western limits of the state and an irre- nhu* line of mountain ranges as yet imperfectly determined, but nearly coinciding with the eastern front ridge of the Alleghany, the (rreenbrier mountains and the Great Flat Top mountain. No sec- tion of the whole state offers perhaps so much that is character- istic, either in its physical geography or geological structure, and none holds out richer promise of valuable practical results as soon as it shall be systematically explored. By far the greatest portion, if not all, of its strata belong to a group of formations, distinguished not only in America but throughout the world, as being the chief depositories of hituminoas eoal. The title of the western carbonif- erous region might therefore seem to be appropriately applicable to it, were we sure that it might not convey to geologists and others a possibly erroneous conception of the class of rocks which it com- prehends. While it is clearly referable to the general period of the bituminous coal, it is by no means meant to signify that the rocks of the region correspond with any exactitude, or indeed have any mioeralogical analogy to the strata which comprise the bituminous

coal formation of most geological writers. Nor, on the other hand, is it settled, that the era of their production was precisely the same during which the coal beds of other countries were deposited. We hold it to be altogether premature, while the geologists of America are jet only on the threshold of their researches, to endeavour to establish an identity of names between our strata and those of En- rope. This too frequent error, prejudges all the broader and more lofty generalizations of the science. In a spirit of caution, there- fore, dictated by the many blunders daily committed in the nomen- clature of our rocks, we shall abstain from giving them a class of European names, not always indeed applicable in the countries where they are employed, and certainly less so in a region of widely different structure, separated by the great interval of the Atlantic. The little that can be said in a detailed way upon particular strata will be descriptive, being convinced that points of nomenclature and classification cannot be ventured upon with profit until there shall have been collected a vast deal more of minute information than is now betVire us.

This western section of Virginia is characterized throughout by geographical features of great simplicity. The surface of the region is undulating, and towards its south-eastern limit, mountainous ; but the loftiest hills rise in gently swelling outlines, and no very promi- nent peaks tower in acute and ragged lines, to denote that the strata have been subjected to violent convulsive and upheaving forces. Everything bespeaks it to have been at one time an expanded plain gently tilt from the horizontal position, so that its surface and the beds of rock beneath decline with a slight but very uniform depres- sion, very generally towards the north-west to the valley of the Ohio.

The form, direction and character of both hills and valleys, give evidence that its inequalities of surface were caused by the fnrrow- ing action of a mighty and devastating rush of waters, which by a rapid drainage scoope<l out enormous valleys and basins in the upper strata, the remnants of which are consequently traceable across the widest valleys from hill to hill, holding the same elevation, thick- ness and inclination to the horizon. It is from this deep excava tion of the strata by natural causes, combined with the other im- portant circumstances of a nearly horizontal position, that we are to draw our estimate of the prodigious resources of a mineral kind possessed by the region before us. Whatever valuable materials lie included in the strata of the district, coal, salt, limestone or iron ore, the horizontal position alluded to keeps them near the surface, or at an accessible depth, over enormously wide spaces of country, while the trough-like structure of the valleys, and their great depth, exposes the edges of many of these deposits to the day, nnder posi- tions in which mining is the easiest imaginable, and with an extent of development not less accommodating to the researches of the scientific geologist than bountiful to the want-s of the community. The same features prevail in the tertiary or tide water district of the state, and ought to awaken there a corresponding feeling of

congratnlatioD. The only essential difference of strnctnre, is the far greater depths to which the beds of this western territory have been excavated or denuded. A greater number of strata are there laid open, contributing to render the deep-seated beds of coal as ac- ce&jible as the superiicial marls of the lower section of the state, and thereby to preserve a beautiful balance in the resources of the two respective regions.

The portion of tlie profile representing this vast and afSnent di- vision of the state, along the particular line to which our observa- tions were chiefly directed, may be regarded as commencing with the Meadow mountain, and extending as far as the Ohio ; but by starting from the point here indicated, it is by no means intended to imply that the great western series of secondary rocks here actually commence. So far as an inspection of the ground along the route observed may be regarded as furnishing information upon this inter- esting point, the probable beginning of this series is to be looked for further to the east, and in all likelihood, is placed on the western bank of Howard's creek, the only position in which an approach to unconformable stratification was observed. As however we have already described the limestones of the Lewisburg valley and the other strata with which they are immediately associated, and as moreover our chief object at present is the presenting some par- ticulars relating to that portion of the great western series which is first distinctly observed towards the summit of the Meadow moun- tain, we shall waive all merely scientific enquiries with respect to the precise boundary of the western rocks, and proceed briefly to describe the structure of this region westward from the point al- ready indicated.

Ascending the Meadow mountain, we meet with blue and red slate in a friable condition, until we arrive at a point more than half way to the top, where grey sandstones make their appearance, forming the cap of the mountain, and like the slates beneath, dipping with a gentle inclination to the west ; descending on the western side the slates again appear, and continue throughout the whole of the extensive flat reaching to the base of the Little Sewell, on the eastern side of which they are soon lost, and a grey sandstone, like that already remarked, again comes into view. The upper portion of the Little Sewell consists of a grey and white sandstone, identi- cal with that observed in progressing further west. Here one or more seams of coal have been discovered. On the western flank of this mountain, the red slate is again observed dipping gently west beneath the other rocks, and here finally disappearing under the beds of sandstone accumulating in thickness in our progress west. Continuing in the same direction, a seiies of these sandstones of various hues and difiTerent textures, including numerous seams of coal, and all dipping as before, but with a diminishing inclination, so as in fact to approach nearly to the horizontal, accompany us through the Big Sewell, Davys mountain, Braokens Kidge, Dog- wood Hidge, Gauley mountain, &c., to a point west of Campbell's creek, where a gentle counter dip of the same rocks may be re-

marked, soon, however, exchanged for the general direction before observed. Here, as indicated in the profile, three great seams of coal display themselves almost continuously for a distance of about 12 miles, stretching in parallel and nearly horizontal bands along the almost mountainous cliffs forming the boundaries of the rich and lovely valley of the Kanawha in the vicinity of Charleston.

Beyond this point, the level of the country declining, we come upon a series of nearly horizontal arenaceous and argillaceous rocks occasionally presenting thin beds of limestone of various degrees of purity, in some cases containing sufficient alumina to render it valu- able for hydraulic lirne. This portion of the series extends as far as the banks of the Ohio.

The sandstones of which it will be seen so large a portion of this region is composed, are remarkable for the enormous size of some of the fossils which they contain, and the shales associated with the coal are even still more rich in some places in these colos- sal relics of a former world. A striking feature already alluded to in speaking of the sandstones near the valley of Lewisburg, is ob- served very generally throughout this region, and is exemplified in some of the clififs of the New river and Kanawha, on a scale of vast extent. I mean the diagonal lamination of the rock — or, in other words, a subordinate stratification oblique to the general lines of demarkation of the several parallel beds of which the whole mass of the cliff or mountain is composed. A similar fact was noticed in describing the tertiary rock of broken shells at York, and the beds of gravel observed in the neighbourhood of Richmond and at other places in lower Virginia. In all these cases, a like agency has been at work in producing this curious structure. In all of them we readily discover the action of tides or currents, depositing upon a surface, originally, by some accidental cause, inclining to the hori- zon, the sands and pebbles, and other materials of the rock, and thus adding layer after layer of the deposited material in directions

Earallel to the receiving surface, and therefore oblique to the general orizontal level. Changing intensity or direction in the transport- ing tide or current, would be accompanied by an alteration in the position or direction of the laminie thus formed — and it is easy to perceiVe, that an almost endless variety of structure in this respect might thus be readily explained. The fact here noticed, furnishes of itself a striking evidence, were any such wanting, of the sub- marine origin of the vast region of which we are now treating. But the organic remains which these rocks entomb, at once demon- strate this to have been the fact— the relics of marine animals being the only remains found among the sandstones which are not immc- diiitelv associated with the coal.

With the view of illustrating the extent of mineral wealth of which this region is possessed, and at the same time of indicating the vast benefits which it may anticipate from a geological and chemical investigation of these resources, I will briefly refer to some of the more important deposits as yet known, of its coal and iron ore and salt.

At Wheeling, and for 14 miles down the river, the cKff or bank presents an uninterrnpted bed of highly bitominons coal, upwards of 16 feet thick, and of such a quality, as to fnrnish fuel for all the dwellings and mannfactories of that enterprising and prosperous town. Above and separated by other beds, are two thinner layers of this material, bat of an inferior value. Associated witli these seams of coal, and lying above the two lower ones, is a bed of lime- stone of upwards of twenty feet in thickness.

At Clarksburg and northward down the valley of the Mononga- hela, there exists one of the richest coal deposits in the state. One of tlie seams in some places in the neighbourhood of this town, is from 10 to 12 feet in thickness, below which, and separated chiefly by a heavy bed of sandstone, there lies a thinner stratum of a more highly bituminous character. These also are associated with a layer cflimestone. We may form some idea of the vast extent of these coal seams from the fact, that from some distance above Clarks- burg, they may be followed with scarcely any interruptions through- out the whole length of the valley of the Monongahela down to Pittsburg. Ascending the Tygart's Valley river, the coal dimin- ishes in thickness and valuable qualities, while the sandstones and limestones increase, the latter in the Cheat and other mountains, near the sources of the river, having a thickness of from 60 to 100 feet.

Coal is also found, though in less considerable scams, along the valley of the Little Kanawha. Near Hughes' river, one of its tribu- taries, it is very abundant ; and in the same neighbourhood, springs of petroleum, or rock oil, have been discovered. Nortli and west of this stream on the ridge, selenite or crystallized gypstim is said to occur, though at what place and to what extent, we are not in- formed.

On the Great Kanawha, the exposure of coal is one of the most extensive and valuable any where in the United States, and here from its immediate vicinity to the Salines, its practical usefulness has been tested on a wide and profitable scale. On the Coal, Gauley and other rivers in this portion of the west, the beds of this mineral are frequently brought to view, and in fact no better general descrip- tion can be presented of its extent, than that it is almost continuous with the vast beds of sandstone, which spread in nearly horizontal planes over nearly the whole of this broad region.

A coal containing much less bituminous matter, occurs imme- diately west of the eastern front ridge of the Alleghany, in Hamp- shire county, lying in nearly horizontal beds, in five successive tiers, and extending for a distance of many miles along the borders of the Potomac. A simple enumeration of the strata here exposed, will furnish an illustration of the resources of this comer of the state, well calculated to inspire astonishment and exultation. Upon a stratum of valuable iron ore, not less than fifteen feet in thickness, there rests a bed of sandstone, upon which reposes a coal seam, three feet thick ; above this, another bed of sandstone, then a two feet vein of coal, next sandstone, then another coal seam of four

feet ; again a stratum of sandstone, and over it a seven feet vein of coal ; over this a heavj bed of iron ore, and crowning the series, an enormoas coal seam of from fifteen to twenty feet in thickness.

The Saline formation, associated with the vast strata of sandstone hefore described, has as yet been almost unexplored, excepting; in the valleys of the Great and Iiittle Kanawha. High np, on the New River, and at one or two points on the Greenbrier, salt water hns been found, and the erection of salt works has been attempted, though hitlierto these efforts have proved unsuccessful, either on account of the weakness or the insufficient supply of the brine. What may be the result of fntnre research in the region east of that in which the salt manufacture is now snccessfuUy pursued, it would be impossible to predict, but from the fact, that tlie rocks of all this region, and among tliem the white sandstone from which the brine of Kanawha is procured, have a gentle western dip, it would appear reasonable to infer, that in the range of the Sewell mountains, and some distance east, where these rocks, which at tlie Salines are many hundred feet deep, are brought nearly to the surface, the sup- ply of salt water might in some places be obtained at a compara- tively inconsiderable depth, and at all events, considering the con- tinuity and identity of the strata over the whole of this wide area, we may reasonably suppose, that the saliferous bed or beds would be found in nearly every portion of it, though perhaps in many places having too slight an impregnation to render the water yielded, of any value in the manufacture of salt.

On the Great Kanawha, wells of various depths, rarely exceed- ing 400 feet, have been sunk on both sides of the river above Charles- ton, throughout a distance of more than twelve miles. The brine thus procured, unlike most other salt waters, contains scarcely any sulphate of lime or gypsum, on which account the process of obtain- ing the salt in a pure crystalline condition, is attended with fewer difiBculties than usual ; and for this reason, the alum salt now pro- cured by the improved methods of operating recently introduced, may be regarded as muriate of soda, in almost absolute chemical purity. The importance and value of the Salines in this vicinity, may be inferred from the fact, that about three millions of bushels of salt are now annually made from them, and that in the manufact- ure of this article alone, more than twice the quantity of coal is consumed every year than is furnished by all the coal mines of east- em Virginia put together. This coal being procured from the hills adjacent to the salt furnaces, is obtained at comparatively little cost; presenting an example of the fortunate adaptation of the resources of a region to each other, of which few equally remarkable are to be met with any where in the world. Enterprise incited by so happy a combination of advantages could not fail of bestowing pros- perity upon a region which is thus blessed, and we, therefore, find throughout the whole extent of the valley, where the salt manufact- ure is pursued, and even over a wide extent of country connected indirectly with its operations, a degree of activity and industry and wealth, which we would in vain look for in our rural districts gen-

erally, and which when first beheld after qnittiDg the wild and almost uninhabited regions by which the traveller from the east approaches the Kanawha, cannot fail to kindle in his mind a vivid sentiment of pride, astonishment and pleasure.

A general stmctore in ail respects analogous to that presented in the portion of the profile last described, pervades the whole of that ▼ast area of which the boundaries have been approximately stated in the beginning of this division of the report. But with fentnres of strong general resemblance, it must not be imagined that local peculiarities do not exist in tne different portions of this region, developing not only many objects of geological and curious interest, but also bringing to light many of the mineral treasures of whicli this favoured territory is possessed. There is no point of view, how- ever, in which the immeasurable riches of this region are rendered more obvious to our minds, than that of the uniform and continuous structure which has already been described. For, it is in these widely spreading strata of sandstone, that nearly all the boundless treasures of this country are enclosed, and the continuous character exhibited by them, gives the strongest possible assurance of a like uninterrupted extension of the various beds of valuable materials which they include. In this view, how magnificent is the picture of the resources of this region, and how exhilarating the contemplation of all the happy influences upon the enterprise, weulth, and intel- lectual improvement of its inhabitants, which are rapidly to follow the successive development of its inexhaustible mineral possessions. In a country where the channels of nearly all the principal rivers have been scooped out in part through beds of coal, where some of them are paved with the richest ores of iron, and where the very rock itself, the sterile sandstone of the cliffs and mountains, is en- riched at certain depths with abundant stores of salt, what more is needed to fulfil the happy and glorious destinies that await it, than to awaken enterprise to a due appreciation of the golden promiHes it holds out, and to direct industrious and active research to the thorough investigation of the character, position, and nses of the treasures it contains ?

Note on the fertilizing efficacy of Green Sand extracted from the report on the Geology of New Jersey by Pro- fesaor S, I), JRogers :

i&

Mr. Woolley, of Poplar swamp, Monmouth county, N. J., ma- nured a piece of land in the proportion of 200 loads of goo<l stable manure to the acre, applying upon an adjacent tract of the same soil, his marl, in the ratio of about 20 loads per acre. The crops, which were timothy and clover, were much the heaviest upon tlie section which had received the marl, and there was this additional fact greatly in favour of the fossil manure, over the putrescent one, that the soil enriched by it was entirely clear of weeds, while the stable manure had rendered its own crop extremely foul.

There can be no doubt that 20 loads of marl per acre mnst he regarded as an unnecessarily bountiful dressing, but computing the relative cost of the two manures when employed in the ratio above stated, we find a considerable disparity of expense in favour of the green sand. Placing the home value of farm-yard manure at 10 cents for each two horse load, and that of the marl at 25 cents per load, we hare the expense of manuring one acre 20 dollars, of marl- ing the same 5 dollars.

Experience has already shown that land once amply marled re- tains its fertility with little diminution for at least 10 or 12 yearn, if care be taken not to crop it too severely ; while with all practica- ble precautions, the stable manure must be renewed at least three times within that interval, to maintain in the soil a corresponding vigour."

Proposed Flan of the Geological Survey.

The survey should aim at three principal results, each of which is essential to a proper development of the native mineral resources of the state.

First, the production of a report descriptive of the minute geol- ogy, practical and 8cienti6c, of all parts of the state.

Second, the construction of a geological map and a series of ac- companying sections or profiles, both necessary to a proper exliibi- tion of the geology of the region, and capable of conveying a fund of useful information, which no mere report can.

Third, the formation of a cabinet designed to exhibit the min- eral materials described in the report, and represented on the map and sections.

As a mere description of the geology of a country, if unaccom- panied by a map and sections, can convey only a very imperfect idea of the structure and relations of its formations, it becomes necessary to have the geographical map as accurate as possible, inasmuch as errors in this will vitiate more or less the geology. The proper basis on which to lay down a geological survey is a minute topo- graphical map, the production, however, of which at the present time, would be too tardy and too costly. The existing state map being very inaccurate in various points, which, if retained in the geological map, might lead to serious practical mistakes, one duty of this survey should be to rectify such portions of the topography as must be corrected previous to laying down the geology. This implies a certain amount of topographical duty, which it is designed to perform only when rendered necessary by the demands of the geological survey.

To the topographical branch of the survey might be attached two or three extra duties, some of which would greatly promote the strictly geological part of the survey, and in like manner augment largely our stock of useful information upon the internal resources of the state. One should be to procure numerous barometrical obser€ation8 of the heights of onr mountains, more especially the

gorges and passes over which roads may from time to time he car- ried. Another oagbt to embrace a set of observations on the drain- age or water power of the several hydrographic sections of the state. This would act usefully in all suggestions for canals, and also tend to the development of manufacturing enterprise.

A general plan only can be given, according to which it would be roost eligible to enter upon the geological researches, for the movements of those engaged in the survey must be shaped to a con- siderable extent by the geological relations of the several districts of the state as they are brought to light. It is deemed proper that the first seasons be taken up in part in a general exploration of all the principal regions of the state, and in part in a detailed investi- gation in a systematic order of each class of formations. In this way a multitude of valuable facts easily reached, will be brought to light by the earliest possible day, and the regular execution of the state map will be in progress from the commencement of the survey, and its ultimate completion greatly expedited.

It is profiosed to connect with these general examinations, a mass of chemical investigations, intended to be of immediate appli- cation in the employment of the msterials brought under review ; also to render annual reports upon such points of the survey as are more pressingly wanted, and which are capable of being completed in a single season, reserving the minute and comprehensive descrip- tion of the whole geology of the state for a general final report. These annual and specific reports can be accompanied by sections across the strata, the execution of which is compatible with much less time than is essential to the construction of the geological map. In this way much definite knowledge can be disseminated without waiting for the final completion of the enterprise, and the map will be greatly benefited by the investigations auxiliary to these profiles. The facts, and general views of the geological structure of the state, brought to light in the reconnoissance, enable one to suggest nearly the directions most proper for the principal sections or pro- files across the formations of the state.

It is proposed to make one lie between the Potomac somewhere near Alexandria and the Alleghany mountain near Cumberland; another from the Atlantic across the Eastern shore and the Chesa- peake bay, at a point between the Potomac and Rappahannock rivers, to reach to the Ohio river near Fishing creek ; a third to stretch from the Chesapeake bay between the York and James rivers to the Ohio near the mouth of the Little Kanawha ; a fourth to commence at the North Carolina line between the Chowan and Roanoke riv- ers, and to follow the general line of the Great Kanawha to the Ohio ; a fifth to stretch from the North Carolina line, at some eligi- ble point in Patrick county, and to meet the former section at the mouth of the New river ; a sixth to reach from the same state line, somewhere in Grayson county, to the valley of the Guyandotte river, and to pursue the general direction of this to the Ohio.*

♦ See Bections on Geolocal Map of Vircrinin and West Vir:Tinia, by WUliam B. Rogers, edited by Jed. HotchkifiB, C. & M. £, 1883.

The detailed location of these six geat lines will be made to de- pend, in great measure, on looal features, and the exigencies arising out of the peculiar geology and geography of each belt of conntrr to be traversed. Their positions have been chosen with a view to intersect the greatest namber of strata practicable, and the most advantageous directions for exposing the formation of every geo- logical subdivision of the state. All the principal ridges are crossed nearly at right angles, and an eye has been had to the greater facili- ties for investigation alforded by the valleys of the large rivers.

As before said, the survey of the zones of country lying along the sections, makes but a portico, and rather a preliminary portion, of the wliole survey. In the construction of the map, and the de- tailed examinations of the systematic survey, the wide tracts of country included between these profiles, would require to be mi- nutely traversed, especially in the longitudinal direction of the strata, to ascertain and depict their boundaries.

A correct knowledge of any region, sufficiently thorough for practical purposes, can only be attained by running from one forma- tion to the neighbouring ones, crossing their boundaries repeatedly in a zigzag course, so as ultimately to cover the whole surface with a network of lines more or less close, according to the degree of intricacy in the geology of each district ; influen( too by the value of the mineral contents of the strata.

It is proposed that the atate cabinet which is to grow out of the survey, should be deposited in a suitable apartment in the capitoL accessible to any citizen of the state, seeking the valuable local and specific information which can only be derived from a collection of specimens.

It is contemplated to commence the formation of the cabinet forthwith ; that is to say, to accompany each annual report with a suite of specimens illustrative of it — to be grouped according to the most natural order in the mean while, and ultimately to receive a thorough systematic classification.

The specimens ought to consist of the characteristic rocks of each formation, arranged as nearly in the order which they observe in natnre as practicable; also the minerals, ores, marls, peculiar soils, organic remains, and other objects to which reference may be desirable by those engaged in agricnltnre and the arts, or by those who may study the mineral productions of the state, for less specific purposes.

As it is proposed to make a chemical investigation of the com- position of these materials an essential feature of the plan, the analy- ses given in the reports will be annexed to the specimens examined, that thus every one consulting the cabinet may know at the same time the external aspect, and the composition of a substance, capa- ble of useful applications. The analyses essential to this, not the least useful part of the survey, from the arduous nature of the task, will be confined to substances of more immediate interest and utility.

Report

OV THS F&OOItESS OF

The Geological Survey

Of

The State Op Virginia,

For The Year 18S6.

OmcB or TBS Boabd or Pubuo Woxeb,

January 2l6t, 1837.

Sib, I transmit to yon herewith, to be laid before the general assembly, the annual report required by law, of the progress made during the last twelve months by the state geologist, in executing the duties with which he is charged.

The contents of this document bear ample evidence of the zeal, diligence and ability, which professor Rogers has brought to the task, and vindicate, even thus early in its progress, the wisdom of the interesting enterprise in which the state has embarked. In the tendenoy of the views presented by it to give a true direction to in- dividual adventure, by showing what it may be safe, what hazardous and what hopeless to undertake, we see the promise of a result of incalculable practical value to the community when these suggestions shall assume the character of scientific deductions based on an am- ple foundation of well ascertained facts.

The picture it presents of the unlocked for extent and value (great as they were known to be) of the mineral resources of Vir- ginia, and the hopes it inspires of the early reanimation of her power and prosperity through the development of these resources, cannot be viewed by her citizens but with unmixed gratification.

To realize at as early a day as practicable the important results fairly to be anticipated from the completion of the survey, will be readily admitted to be a matter of much public interest In view of which, this board, concurring in the reasons presented in the report for a more extended and efficient organization of the geological corps, beg leave respectfully to recommend the enlargement of it there proposed to the favourable consideration of the legislature. I have the honor to be, Very respectfully,

'Wyndham Robertson, President of the Board 0/ Public Works,

To the honourable the SpeaJcer of the House of Delegates.

Report.

I beg Icayo to make the following report of the progress of the geological survej of the state during the past year.

Proper assistants having been appointed, as provided in the law, the active investigations in the field were begun about the middle of April, and were continued without interrnption until the begin- ning of November. During this time and nearly up to the present date, whilst not myself engaged in the task of exploration, the chemical researches connected with the survey have been steadily progressing under my immediate and constant superintendence.

In aid of the field operations and as an important preliminary to the correct delineation of geological details upon the state map, the work of taking accurate copies of the county maps was begun early in the season, and has progressed so far as that at the present time more than fifty of these maps are ready for the uses of the survey.

In the course of the geological investigations of the season up- wards of twenty boxes of specimens were collected, illustrating the structure and the economical resources of the various districts vis- ited, and furnishing materials for analytical examination.

In the prosecution of the work, each of the following regions was more or less the theatre of research.

1st. The peninsula of the Potomac and Rappahannock rivers.

2d. The counties bordering on the Rappahannock to the south.

3d. The bituminous coal fields of Henrico, Goochland, Chester- field and Powhatan counties.

4th. A portion of what is called the Gold region in the counties of Fauquier, Spotsylvania, Culpeper, Louisa, Orange, Goochland, Fluvanna and Buckingham.

5th. A transverse belt of country extending westward from the neighbourhood of Fredericksburg to the vicinity of Moorefield in Hardy county.

6th. The northern counties of the valley from the Potomac to

the neighbourhood of Lnraj and Newm&rket, together with a por- tion of the adjacent mountain district to the west.

7th. The counties of Washington, Wythe, Smyth, Montgomery and Grayson, in the south-west.

In most of the districts above enumerated the investigations were conducted in the manner of a reconnoissance with the view of establishing a basis for future specific and accurate research, and it is important to bear in mind that from the diversified features of our geology and the almost total absence of any knowledge of it from previous investigation, such preliminary surveys in each dis- trict become indispensable to the successful and rapid prosecution of the minute enquiries which are to constitute the chief value of the survey. But wbile for the most part the operations of the past year were of the general character here described, in some districts the observations were carried into minute detail, and in all of them a great number of facts were gathered calculated to illustrate their geological structure and the nature and extent of their mineral re- sources.

As, however, the exhibition of details at present would obvious- ly be incompatible with the design of the annual reports upon the progress of the survey contemplated in the law — they wiU be re- served for incorporation in the final report— in the moan while hav- ing the benefit of a revision with the additional lights acquired in the prosecution of the work.

In the first of tiie regions above indicated, the observations were very numerous and minute. Nearly all the ironortant exposures illustrating the geology and mineral resources of tne peninsula were carefully examined; the strata observed in each being noted, and specimens retained for illustration and chemical research. The boundaries of the two divisions of the Tertiary, the Eocene, and Meioceno, were determined with all needful accuracy upon the Po- tomac and Rappahannock, and were approximately settled as to intermediate points.

The disposition and nature of the beds composing the Heiocene in this portion of the state were found to be conformable with those of the peninsula of the James and York rivers, chiefly referred to in the report of the reconnoissance published last year. Here as well as in that region the hluUh marls were found low down in the series of Meiocene strata, and a thin band of ferruginous rock or clay was generally observed to be interposed between them and the diluvial sand and gravel Indeed so uniform is the position of this layer, in relation to the marl, that its discovery at any point would furnish grounds for the strong tf not confident anticipation of finding marl beneath.

A large proportion of the marl beds of the Neck, containing car- bonate of lime in sufiicient quantity to prove available in agriculture, are of the description which has just been noticed; at the same time strata in which the shells are mingled with sand and clay of various shades of yellow and brown are not unfrequent. A frag- mentary rock, consisting of broken shells cemented by carbonate of

lime, sometimes partiallj orystallizecl, and white pulvemlent or chalky marls are also found.

Of these the most ahandant or hlue marl though often present- ing the appearance of great riohnetfs from the numher of perfect shells which it contains, has been fonnd to be less charged with oarbonate of lime than some of the other varieties.

The mean of upwards of fifty specimens of this description which have been analyzed in the course of the season is 86 per cent, of carbonate of lime, and in few instances did the result rise as high as 40 per cent., while the light coloured rocky and chalky marls yielded a proportion more than twice as great.

In general the upper beds of the Meiocene in this district were found to be destitute of fossils though full of their casts and im- pressions. These strata consisting for the most part of light col- oured sandy clays, frequently of great depth, are distinguished by a sulphureous smell, and often by an acid and styptic flavour. They rarely contain an appreciable amount of carbonate of lime, but are impregnated with sulphate of lime (gysnra), together with sulphate of iron (copperas), sulphate of alumina, sulphur, and sometimes even a sensible amount of sulphate of magnesia (Epsom salts). The addtty of these clays is often sufi9cient to make a pungent impres- sion on the tongue, and their sulphur is distinctly recognized by the characteristic odour exhaled, especially when they are heated. In many localities, as in the Rappahannock cliffs in Richmond county, the gypsnra occurs in crystals of sufficient magnitude to be sepa- rated by the fingers, and sometimes in the attractive form of trans- parent Selenite but its more usual condition is that of delicate silken crystals distributed through the mass and visible only upon close and attentive inspection.

Numerous specimens, taken from strata of this kind in various parts of the Neck, presented a great similarity of composition, tlioogh not without much variation in the proportion of the gypsum and other ingredients which they contained and like results were obtained from the analysis of the overlying and once fossiliferous beds in other places where the Meiocene marl occurs. The cause of the extensive destruction of shelly matter once embedded in these days, was clearly traced to the iulphurie aeid originating in the de- composition of sulphuret of iron, which permeating the beds of mar( converted the carbonate into sulphate of lime. This being in part retained, formed the crystals of gypsum now discovered in thrae strata ; at the same time, that by the decomposition of the sulphuret, the sulphate of iron and other ingredients above noticed Were brought to light ; and the overlying layer of ferruginous rock or clay most probably owes its origin to the same source.

The presence of gypsum in these beds suggests the interesting en- quh-y as to how far they may become available in the agriculture of this and other regions similarly situated. Upon this point I shall embrace the present opportunity of a few brief remarks. Where they contain a considerable amount of this ingredient, say 10 per cent., and are impregnated with no injurious or counteracting agent,

no donbt can exist as to their beneficial inflaence upon the soil ; and in such cases, besides the peculiar ameliorating effect of the gypsum, they woold impart the farther advantage of an improve- ment in the texture of the land. But as in most instances the pro- portion of gypsnm does not exceed two per cent., and as it is olended with the other sulpliates as well as free sulphuric acid and sulphur, ingredients which in considerable quantity are known to be destructive to vegetation, it would naturally be inferred that such 'materials, if not inert, must be actively injurious in their effects upon the soil. Experience too has seemed to give authority to this opinion, since when applied to the land, as in some cases these materials have been in considerable quantities, a diminution or even temporary loss of productiveness has ensued. Still, how- ever, it should be remarked that experiments thus roughly made, by no means justify any confident conclusion on the subject. The effect of such substances on vegetation must greatly depend on the quan- iity in which they are applied. \Vhen prodigally spread over the land, there can be no doubt that they inflict serious, though by no means irreparable injury. Such also is known to be the conse- quence of a redundant application of the ordinary calcareous ma- nures. But obsorvution would seem to prove that, when sparingly employed the materials referred to are productive of a very decided improvement. In many parts of lower Virginia these gypseous and acidulated clays, applied under tlie impression that they contained a useful proportion of green sand, have been found to impart new and surprising energy to the soil.

Without entering upon the obscure question of the modug ope- randi of mineral substances, including calcareous manures, upon plants, we cannot doubt that in part, at least, their influence is that of directly stimulating the vital organs concerned in vegetable growth, — nor can we avoid believing that with plants as w*ith ani- mals the number of substances adapted to produce this effect is far from being restricted to the few materials most commonly in use. We have the positive testimony of numerous experiments to prove that many substances of high chemical energy are capable in small quantities of favouring the growth of plants.

Without, therefore, advancing any hypothesis as to the peculiar agency of the sulphates and other matters contained in these gypse- ous clays, or attempting a priori to pronounce upon their effects either as salutary or injurious, I feel suflSciently sustained by obser- vation in expressing it as my opinion that they will one day be made available in the agriculture of this region — and I would urgently suggest the importance of making careful experiments to determine the quantity in which they may be safely and advantageously ap- plied. But in all such trials let it be borne in mind that only small quantities of such of these materials as are strongly styptic and sulphureous should be employed.

The Eocene strata of the peninsula are comprised in the district lying between a line connecting Mathiass point on the Potomac with the mouth of Chiugotoague creek on the Rappahannock, and

another and crooked line nearly coinciding with the eastern bound- ary of the sandstone formation in Stafford connty. These beds were fonnd to exhibit less aniformity of arrangement than those on the Pamunkey and James rivers, formerly described. In general, the lowest stratum is of a dark greenish blue colour, and those which lie above it have various shades of yellow, greenish grey and brown. In many instances the upper strata are devoid of shells, but replete with their casts and impressions, and with the exception of gener- ally containing a notable amount of green sand, are strikingly anal- offous in coxnposition to the gypseous and sulphureous strata of the Meiooene. To make the resemblance still more complete, a thin layer of ferruginous gravel or rock frequently overlies these beds, and forms the boundary between them and the Meiocene.

This remarkable resemblance in the situation and character of the two, while it leads us to infer the action of like chemical agen- cies upon both, assures us of a similarity in their agricultural effects.

The Eocene marls of the peninsula present much diversity of composiUon. Whilst in some localities the shelly matter forms a very considerable part of the mass, in others little or none of it occurs. The green sand often forms a prominent ingredient, and is in no case absent, though frequently the amount of it is very inconsiderable. Gypsum is also occasionally to be met with ; and this as well as the other sulphates is not excluded from the beds containing shells. A minute analysis of some of the more impor- tant of these marls is now in progress, but the research is one requiring much time for its completion.

It may be useful to state, that in general the shelly strata of the Eocene in this district do not contain more than from ten to fifteen per cent, of carbonate of lime, and that in many instances, where the shells are quite conspicuous, the proportion is less than one half of this. In the shell rock, such as occurs in several places on the Potomac, as much as eighty-two per cent, has been found.

It would therefore appear, that while in some instances there is a sufficient amount of carbonate of lime in the mass to give it the character of a rather poor calcareous mnrl, the proportion of this ingredient in generol is too inconsiderable to impart any high de- gree of agricultural yalue. For much of the benefit derived from the application of these substances to the soil we must look to the green sand, gypsum, snd perhaps other ingredients which they con- tain. Experiments now in progress with some of the varieties con- taining little or no shelly matter, indicate decidedly beneficial re- sults ; and there is but little reason to doubt that more extensive trials of these materials, conducted with judgment and caution, will confirm the views at present entertained of their capacity of being highly nseful in agriculture.

From the absence of shelly matter in the strata of Meiocene and Eocene above referred to, they have hitherto been considered as en- tirely destitute of value. The fact now made known of their con- taining, nearly in every case, a notable amount of gypsum, must therefore be looked upon as an interesting discovery, and should the

observations already made, upon the fertilizmg effects of tbe mate* rial of these beds, be sustained by a wider and more varied ex- perience, our views of tbe agricultural resources of the eastern por- tion of our state will be greatly and cheeringly enlarged. Believing that such is to be the result of further experiments on the subject, I look with pleasing anticipation to the time when the invalnable shell marl of the country will not be without a substitute in those districts to which it has been denied, and when ahnatt every ratim in eastern Virginia will be resorted to for materials to improve the productiveness of the soU.

The researches in the counties bordering on the Rappahannock to the south, were chiefly confined to an inspection of localities of marl and the examination of the strata associated with it in several of the more important points. The numerous specimens of tbe Meiocene marl which were collected in the reconnoissance, have been submitted to analysis, and with the same general results as have been stated in regard to the marls of the Neck, the pulveru- lent and light coloured varieties always yielding a much larger per centage of carbonate of lime than the blue marl, and sometimes, as in the case of specimens from Mr. Oaks's and other places in Middle- sex, amounting to about 80 per cent. Gypseous and sulphuretted clays were found here as in the Neck, and at some points imme- diately on the river the SeUnite was discovered in conspicuous crystals. An analysis of some of these gypseous clays gave from 8 to 10 per cent, of this ingredient.

Before concluding this sketch of the investigations in the Ter- tiary region during the past year, it may be well to remark that in tbe event of an ampler organization of the means of exploration, urgently demanded by the survey, the revision of the ground already traversed will be aided by the employment of a boat built and equipped for the service. With such facilities, the exploration in districts hitherto unexamined, will be carried on with increased accuracy and speed.

The researches which were made in the bUvminovs coalfield* of Henrieoy Goochland &c. were in the first place directed to the de- termination of the boundaries of the region in which the coal meas- ures occur. With this view, it was explored by transverse lines, and throughout its entire circuit ; but further examinations are re- quired to ascertain its extent and stracture with the degree of accuracy necessary to represent it on the map. And before this delineation can be usefully made, the important errors in this por- tion of the map will require to be corrected.

All the important workings for coal, together with a large num- ber of shafts or diggings of minor interest, were examined: but additional investigations are required to secure that exact knowl- edge of the complicated stracture of these coal fields, which may serve hereafter as a guide to enterprises in this region. I feel safe, however, in remarking that the observations thus far made, whilst they indicate that the region containing coal is more extensive than I had supposed — are calculated to strengthen the opinion that in no

part of the basin is the depth of the coal 00 great as from a view of the direetions of its outcrop woald he supposed — and if, as is proha- bly the case, the floor upon which it rests is of so undulating a fignre as in some measure to divide the region into several basins — there is a reasonable hope of reaching this mineral at comparatively moderate depths even in the centre of the field.

Although these coals have long been extensively in nse for do- mestic and manufacturing purposes, no systematic investigation of their ehemieal composition has hitherto been attempted, nor have any just data been furnished for comparing them with the coals of other regions, either in this country or abroad. The minute inves- tigations on this subject in which I am now engaged, have already made me accurately acquainted with the composition and heating powers of upwards of twenty of these coals, and I feel no hesitation in saying, in view of these results, that I am prepared to vindicate their claim to a very high rank in comparison with the coals of most other parts of the world. Without entering into details, it may be useful to state that tn the specimens hitherto examined the amount of bituminous matter varied from 27 to 88 per cent, of the whole, the ash in general from 2 to 6, and that the combustible value or heating power of the several specimens, as determined by a very perfect process — is represented by an amount of pure charcoal from 75 to 89 hundredths of the whole weight of the coal.

Whilst referring to the valuable character of these rich deposites of bituminous coal, I am anxious again to call attention to the Iron ores which accompany them in several places. Since the former re- port, in which allusion was made to the probable importance of these ores to the manufacturing industry of eastern Virginia, sev- eral specimens have been submitted to chemical analysis, and from the results obtained, the really valuable character of the ore may be considered as satisfactorily established.

A specimen of Hematitio ore from the neighbonrhood of Trabues pits in Chesterfield, gave in the 100 grains the following ingre- dients:

Per oxide of iron, 85.15

Silica, 4.20

Alumina, 4.00

Water, 6.50

The existence of this minernl in immediate contiguity with the coal is a fact of such obvious importance, that no commentary is needed to make it deeply interesting to persons of capital and enter- prise, who may be concerned in developing the resources of this portion of the state.

In that portion of what is called the gold region of the state in which research was prosecuted, all the important openings were vis- ited in which the precious metal is or has been obtained. Many circumstances of practical and scientific interest connected with each of them were noted, and suites of illustrative specimens pro- enred. But much additional observation is required before it will

be safe to speak confidently of the geology of these veins or to pro- nounce upon the extent to which they are likely to contribute to the resources of the state.

I would not have it inferred from these remarks, that any unfa- vourable impression as to the ultimate value of our gold mines, has grown out of the various facts relating to them which have been thus far collected. On the contrary, I am still of the opinion that the working of the innumerable auriferous veins of this wide region is destined to become an important branch of the systematic indus- try of the state. And whilst I would deprecate those overwrought anticipations of their productiveness which the brilliant develop- ments occasionally made are calculated to inspire, I wonid give a sober encouragement to the enterprise and capital which they attract, believing that in many instances these veins have that wholesome degree of fertihty which is capable of giving to indus> try a steady incentive and a reasonable reward.

In exploring the belt of country referred to under the hth head, an approximate profile was constructed extending from Fredericks- burg to Moorefield, exhibiting many of the important features in the structure of the intervening region. The country on both sides of this line was examined rapidly though with considerable minute- ness, excursions for specific objects being made as far as the Poto- mac on the one hand, and to the remote parts of Culpeper, Rappa- hannock and Orange counties on the other.

The valuable strata of freestone which overlie the primary rocks near the lower end of this line were inspected at various localities, near Fredericksburg, below this city on the river, and at several points in Stafford county, and it is believed that some useful views were attained with regard to the geological character of these beds as well as the circurastAUces under which they furnish the most durable material for building.

Beyond this to the west, the primary rocks, the slates of the gold region, together with the iron ores occurring in them, and the nar- row belt of Talcose limestone which shows itself on the Rapidan, (Rapid- Anne,) at Mountain run, and other localities were succes- sively observed. The limestone here referred to is a continuation of the narrow belt which appears between Lynchburg and Scotts- ville on the James river, and is laid bare at various points in Al- bemarle nnd Orange. A fragment from the cliff at MitchelPs ford on the Rapidan, (Rapid- Anne,) yielded in the 100 grains 81.81 grains of carbonate of lime, thus vieing in purity with the lime- stones of the Valley — and indicating the advantages which might be conferred upon the soil of the neighbouring country by the use of such lime as it would furnish. The iron ore from the site of the old works at Chancellor's, was examined and found to be of good quality.

At a short distance to the west of Germanna ford, commences the region of calcareous shales and sandstones. This, though of considerable breadth, and extending from the Potomac southward through Orange county, and probably, with some interruptions, far

into North Carolina, constitutes an iioportant feature in our geology to which little or no attention has hitherto heen given. These shales and sandstones were traced in Fauquier, Culpeper, Kappshannock, Orange, Prince William and Loudoun counties, and the interesting fact determined that the Fotomae marble constitutes one of the heds of tliis series of sedimentary rocks. A calcareous and very mixed conglomerate, similar to that of the Potomac, was found near the eastern flank of the Bull Run'mountain, continuous with the quar- ries upon that river. In topographical features and character of the soil, as well as in geological structure, this region bears a striking resemblance to what are called the red sliale lands of Pennsylvania and New Jersey. In no district of the state is the connexion be- tween the nature of the prevailing rocks and the qualities of the soil, more strongly marked than here. The red slaty sandstone, containing a considerable amount of carbonate of lime, imparts pro- ductiveness to the adjacent red soil, while the more siliceous rocks are marked by the sterile character of the fields where they are ex- posed. In some of the gray micaceous sandstones of a coarse text- ure, such for example as are seen in the neighbourhood of Clover- land near the base of the Bull Run mountain, I discovered visible crystals of carbonate of lime, and found the rock in general to be quite calcareous. Hence the rich growth of clover which adorns the fields, and the luxuriant vegetation which springs up among the debris of the quarries.

A curious teature in the composition of some of these rocks is the presence of the green carbonate and the sulphuret of copper. This fact, which appears to have been observed at a very early period after the settlement of the country, has unhappily kept alive the hope of discovering in these shales veins of a workable copper ore, and has led to repeated enterprises in mining, from which no really profitable result appears ever to have been derived. Most of the openings, either ancient or modem, have disclosed nothing more than a calcareous shale slightly meef with the green carbcnate, and making in some cases a superficial show of richness where analysis discovers only an insignificant amount of the enticing mineral.

The specimens of the ittlphuret of copper found in several places are frequently of a very favourable character, but no indications can be discovered of its being present in sufiicient quantity to justify the erection of works for smelting.

In this series of rooks there occurs a blackish slate marked with the impressions of fossil vegetables, and containing much bitumi- nous matter and thin seams or rather films of coal. Similar impres- sions are abundant also in some of the other associated beds. In- deed, the general aspect of the rocks of this district is at first view not unfavourable to the idea that it embodies valuable fields of coal. But while I would by no means assert that seams of this mineral of one or two inches in thickness may not occasionally be found, lean- not think U probable that a/iiy vein of workable extent wiU ever be dis- covered among these shales.

Besides the belt of limestone already referred to as seen on thf

Rapidan or Rapid- Anne in the line of onr section, another narrow ledge is found in Fauquier and Loudoun counties, to the west of Cat- octin and Bull Run mountain, and widening as it approaches the Potomac. This rock, which is well adapted to the making of lime, is in some places burnt for that purpose, but it is painful to re- mark, here as in other places similarlj fortunate in position, how little benefit is reape<l from the possession of a iresooroe of such high agricultural utility.

In many parts of the Blue Ridge in the neighbourhood of the transyerse belt whose general characters I am describing, virgin cop- per and the green carbonate have been discovered in thin veins and small masses in the body of quartzose and epidotio rook. In the neighbourhood of Stoney Man, one of the loftiest and wildest of the peaks of this range, near Swift Run gap, and at several other points, small specimens have been picked up, and their richness both in the metal and its carbonate have inspired the sanguine with a confident belief of the existence in the bosom of the nAountain of treasures of this nature of exhaustless extent. But in regard to all such antici- pations it should be borne in mind that the quantity is not leas im- portant than the qtmlity of the ore to stamp it with real value, and that until far more minute and extensive researches in regard to these ores have been made in the localities where they are found than have ever hitherto been attempted, it will be impossible to have any grounds for judging of their extent, and it will be as unwise as hazardous to engage in expensive schemes of mining on their account. Yet I would not have it understood that such researches are to be considered as hopeless or inexpedient. I would rather rejoice to see investigation active, at the same time that in duty to the public interest I would caution against that precipitate and over-sanguine spirit which will not wait for deliberate research — a spirit which in no instance is more likely to terminate in loss and disappointment than when excited by objects of this nature, involved as they must be, even to the diligent scientific explorer, in unavoidable obscurity and doubt.

In the oountics of the valley and in the neighbouring mountaiiu the researches were of a character deeply interesting to the progress of the survey. After much toil and perplexity, occnsionea by the rugged features and complicated structure of the mountainous dis tricts which were examined, the true relations of the rocks and min- erals of this portion of the state were satisfactorily determined. The discovery of a key to the intricate geology of the region west of the valley as connected with that of the valley itself, must be re- garded as a result of the highest practical as well as scientific inter- est. Such a guide having been obtained, the researches in this most difficult field of investigation may be expected to progress with cer- tainty, accuracy and expedition. For this important general result I am largely indebted to the services of my chief assistant, Professor fl. D. Rogers, who, connecting the survey of Pennsylvania, of which he has the chief direction, with that of the contiguous portions of our state, has been enabled to throw new and valuable lights upon

this and other difficalt points in onr geoiogj, until now entirely mis- understood.

In connexion with these general investigations, which were indis- pensable as preliminaries to the minute research essential to the pro- daction of a geological map of the Appalachian region, yarious im- portant observations were made in regard to the limestones, iron ores and coals of the valley and mountains to the west. Numerous specimens of each of these materials have been subjected to chem- ical examination, and from the mass of resalts tlius obtained valua- ble light has been shed upon their nature and useful applications in all the varieties of form and composition in which thejr occur.

A brief statement of some of the geological and chemical results thus far obtained, will serve to illustrate the momentous practical bearings of the investigation in progress in this region, and to dis- play, in a new and gratifying point of view, the vast extent and value of its mineral treasures.

Of the twelve rocks, each marhed by certain dietinctite eharaetera, companng the tnountains and valleys of this region, it has been deter- mined that at least eight are accompanied by beds of iron ore. Each ore has distinctive marks by which it may be recognized, and pecul- iarities of composition, fitting it for certain uses to which others would be less happily adapted. Thus, in the quantity and variety of this material in all its valuable forms, our state is now proved to have no rival, unless, perhaps, Pennsylvania may be such. Looking to Uie immense extent of the region over which these rooks are spread, and to the structure of its mountains and valleys — bringing to light at various points each of the twelve principal strata which it comprises — freighted, in great part, with the most inestimable of metallic products, it becomes evident at ouoe that the topography of the rocks and mineral resources of this region, as will be exhibited in the general geological map, is destined to bestow upon it a new and fdmost nnhoped for interest. With such incentives, and with such a guide, enterprise directed to this portion of the state can neitiier falter or be disappointed. Anticipation confiding in the certain deductions of cantious scientific research already begins to sketch the gladdening picture of successful industry — crowding population and wide-spreading improvement, which at no remote day, it will be its happy lot to realize.

The eoals of this region were examined at numerous points from the Potomac to the neighbourhood of the Tennessee line, and although much additional investigation is required to ascertain the number and extent of the workable seams of this mineral, enough has already been done to satisfy me that they will, ere long, be re- garded as one of the most valuable resoarces of this part of the state. On a former occasion I adverted to the peculiar adaptation of some of these coals in the raw state, to the manvfactnre of iron. The analysis of specimens from several localities, not visited before this season, indicates a composition admirably suited to this use. As examples of coals of this description, I will refer to the three fol- lowing :

Ist. Tbe Beml-bitaminons coal, from Thorn's creek and Strou- ble's rnn, in Montgomery coanty. This consists of

Carbon,. 80.20

Bitumen, &c., 13.60

Ash, 6.20

The combustible value or caloriHc power of 100 parts of this coal is equivalent to that of 92.6 parts of cai'bon.

2d. Semi-bituminous coal from near Lewisburg. This consists of

Carbon, 78.84

Bitumen, &c., 14.16

Ash, 7.00

The calorific power of 100 parts of this coal is equivalent to that of 87 parts of carbon.

3d. Catawba semi-bituminoiis .coal — Botetourt connty. This consists of

Carbon, 78.50

Bitumen, 16.50

Ash, 5.00

The cfllorific power of 100 parts of this coal is equivalent to that of 89.4 parts of carbon.

These and similar results obtained with regard to specimens from other localities in the Appalachian region, illustrate the fitness of these coals for the manufacture of iron, a quality which must be looked upon as giving them incalculable value, when their immedi- ate vicinity to inexhaustible supplies of the ore is taken into the account.

The vast advantages in point of economy resulting from the employment of the raw eoaU of Wales, Scotland and France, in the smelting of iron ores, though not unknown in this country, appear as yet to be but imperfectly appreciated. It may therefore be prop- er to remark, that wherever in Europe, coals of the proper chaise- ter can be obtained, they are preferred to every other material used for this purpose'. It is surely greatly to be desired that a trial were made of our semi-bituminous coals in the smelting furnaces, since by the result of a successful experiment of this kind, if carefully per- formed, a new impetus would be given to the manufacture of iron in Virgina. At the same time, the importance of applying the iiot air blast, especially in connexion with the use of these raw coals, cannot be too urgently insisted upon. The large mass of experience collected of late years in Great Britain, as well as on the continent, conclusively demonstrating the great economy of this process, and the very general disposition in Europe to adopt it wherever prac- ticable, ought to furnish a sufficient inducement for its introduction liere; and since, as Berthier hss shown, its advantages are aug- mented by connecting it with the use of raw coals, an especial mo- tive is presented for its adoption in the furnaces of the region of which I am at present treating. Should these improvements be brought into extensive operation, as in process of time they most

assnredlj will, the prosperity of this vast and almost forgotten por- tion of the state, will outstrip any thing that the imagination of its present inhabitants can conceive. What snrer foundation for the permanent wealth and power of a community can be found, than the stores of coal and iron embosomed in the rocky strata of its hills and valleys, and what more efficacious stimulus to the mechanic arts, to industry in general, and to the advancement of all practical and profitable knowledge, than the multifarious pursuits linked with the manufacture of iron t

Of the limestones of the valley, numerous specimens have been analyzed, with the view of determining the peculiar composition of each variety — point of much importance in applying them to agri- coltaral or other uses. A sketch of some of the results of this in- vestigation, which is still in progress, may here be fitly introduced. I find that the earbonate of magnesia is a much more abundant and common ingredient in these limestones than has hitherto been sus- pected. All the rocks already tested as hydraulic cements, contain a large proportion of this substance. I have become convinced that a great number of the magnesian limestones of the valley possess the property of hardening under water, and I am at present en- gag in extensive experiments upon their qualities in this respect.

The deep blue, almost black limestone of a fine grain and rather smooth fracture, which is commonly burnt for lime, contains only a slight trace of carbonate of magnesia.

Its constituents are carbonate of lime, silica, alumina, protoxide of iron, and a trace of carbonate of magnesia, with a little organic matter.

The amount of carbonate of lime usually present in this valoable rock may be seen from the following table of the quantity con- tained in seven specimens of this description procured in different parts of the valley. A great number of similar results might be added to the table from my minutes, which include the composition of more than thirty specimens, but the seven here given will suffice.

8G.3 83.4 85.2 87.5 82.9 83.6 82.8

It appears from this that no great diversity exists in the quality of this rock in different localities. Taking 84 per cent as the average quantity of carbonate of lime present in this variety, it is easily inferred from the composition of the carbonate, that each 100 lbs, of the rock ought to yield 47 lbs, of lime.

The dark dun coloured limestone of very close grain and sorai- conchoidal fracture, is even more exempt than the preceding from carbonate of -magnesia, and is richer in carbonate of lime. The specimens examined gave an average of 88 per cent. Accordingly, where it has been burnt, this rock has yielded lime of great purity.

The limestone of a dull greyish blue colour and of coarse texture, contains a notable portion of silica and carbonate of magnesia and has often the properties of a hydraulic cement. The following is the composition of one of several spedmens of this variety which

were analysed. It was obtained (torn a hill one mile north of Staanton. One hundred grains contain

Carbonate of lime, 49.60

Carbonate of magnesia, 3S.87

Silica, 7.60

Ox. iron and alumina, 2.83

Tbe rock of a light greyish blue colour and of very compact text- ure, almost cdways contains a large proportion of silica as well as carbonate of magnesia. The hydraulic lime made at Shepherds- town is generally procured from this rock. The following is the composition of a specimen of this kind from Reynolds's quarry. But it is to be observed that even from this neighbourhood the cement rocks exhibit a great diversity in the proportion of their constituents. One hundred grains contain

Carbonate of lime, 82.17

Carbonate of magnesia, 18.86

Silica, 88.98

Ox. iron and alumina, 4.17

The rock to be ased in preparing cement for the locks of the James river canal is of this kind. It is obtained in Rockbridge county, and contains

Carbonate of lime, 38.33

Carbonate of magnesia, 16.30

Silica, 86.60

Ox. iron and alumina 6.33

It will appear, from what has been stated in regard to the aspect of the several varieties of limestone above described, that any care- ful observer may in general distinguish between those rocks which are raagnesian and those which are not. This is a matter of no atiiall importance, especially in the agricultural employment of the lime, since if not actually injurious, as was once supposed, the magnesia is at best an inefficient substitute for lime. Moreover, the rocks con- taining it are more difficult to bum than the others, and unless when hydraulic, the Itme they yield is not so well adapted for mortar.

The great abundance of the dark blue limestone, so admirably suited to the uses of the farmer, holds out a strong inducement to the employment of lime upon the soil. In my former report I attempted to remove the mistaken impression, that the land of limestone regions is already sufficiently imbued with calcareous mat- ter, by appealing to the results of analysis ; and I would now repeat the observations tlien made, as having been confirmed by farther examination.

There cannot be any fact in practical agriculture more clearly proved than the beneficial action of lime upon the soil of limestone regions, such as our valley. Why then is it not extensively used by 'the farmers in that portion of the state? With so sure and in- exhaustible a means of improvement (everywhere around them) every hill and valley might be made productive. This is one day to

be tbe result of the system atio and general use of lime, aided by an improved sclieme of agrionltnre. But I woold gladly speed the progress of amelioration, by pointing to tbe invalaable resource which nature has provided for the improvement of this country, and by expostulating earnestly, on grounds of science and experience, with those who are disposed to neglect the boon.

The reoonnoissanoe of the gouth-weBtem eountua embraced a rapid examination of parts of Grayson, Wythe, Montgomery, 8m3rth and Russell, and included a more detailed investigation of tiie 1, plsister and salt of this region.

The lead mine$ are situated near Cripple creek, about four miles from Poplar camp furnace, in a direction a little south of west. Tbey are within half a mile of the south bank of New river, and about one and a half from the base of the Poplar camp or Iron mountain. The ore occurs in a siliceous limestone generally of a white or grey colour, though sometimes blue. Tbe veins are irreg- ular in dip and direction, frequently turning very abruptly, and sending off leads or branches. On either side of the ore, the en- dosmg materia] continues of a soft texture as far as the walls of limestone enclosing the whole, which vary in their distance from each other. On the upper side of the vein is generally found a red- dish clay. On the lower side is a firmer material containing crystals of phosphate of lead and other matters. This the workmen here as in Europe call clinker, and they reject it as of no value.

Tbe vein proper is in general twelve inches thick, and contains the following ores of lead :

1. Compact snlphuret or blue ore.

2. Compact carbonate or grey ore.

8. Crystallized carbonate — or Cat's tooth,

4. Mixture of carbonate and oxide — brown and red ore.

6. Finely divided sulphnret — black ore.

The sulphuret or bine ore occurs only in some parts of the vein in irregular masses or cups as they are called, and does not occupy one half of the productive portion of the vein. The other ores oc- cur along side of it and are mingled with it. The adjacent limestone is sometimes in a soft and crumbly condition, and curiously spotted — eometimes in the form of a beautiful white spar containing crys- tals of cubical galena.

There are six openings at present wrought, each having drifts below tbe surface at various depths from 30 to 120 feet. These are all comprised within a space of less than 160 yards square. To tbe 8. W. are numerous pits from which ore was extracted in former years. The entire distance through which the lead has been traced and wrought in this vicinity is about half a mile. The general direction of the veins is nearly N. E. and S. W. One of tbe same description has been found at several yioints to tbe N. £., and among others at Mr. Sawyers\ on Reed creek, about 7 miles from the mines. Blue ore has also been found in small qaantity on Mr. 6raham*s land, at an equal distance, in a due north direction. Whether a valuable amount of the ore exists at either of these places,

or in any of the nnmeroas localities in other and distant parts of the valley in which specimens have been discovered, it is impossible to say without much farther investigation.

The extent of the workable ore, at the mines just described, ap- pears from the indications observed, to be very considerable, and it were grently to be desired that a systematic mining of these veins were undertaken upon a scale commensurate with their value. At present a wasteful method of excavation is threatening serious injury to the interests of future mining operations in this region, and if persevered in, will destroy the usefulness of many portions of the veins now worked by rendering them almost inaccessible or incapable of being farther wrought

In the operation of washing at what are called the Buddies, though conducted more judiciously than the mining — there is evi- dently a larger proportion of useful material carried off than ought to be allowed to escape. This fact I ascertained by an examination of the ochreous earth deposited by the stream at some distance be- low the Buddies.

The position of the veins in a hill near the south bank of the New river makes it obvious that a tunnel driven through the base of the hill into the veins, would afford great facility to the operations under ground, whilst it would open up a great extent of the ore and would dispense with the expensive and inefficient process of raising the ore in buckets. By locating the Buddies and the furnaces at the mouth of such an adit, a combination of advantages would be secured. It is estimated that 25 per cent, of the material as it is procured in the crude state from the mines, is removed by washing at the Buddies, and that 100 lbs. of the rough or 75 of the washed ore will yield 50 lbs. of metal. A result so very high ought to in- vite attention to this interesting region, especially when it is con- sidered that this is the only available body of lead ore in any of the Atlantic states.

The fact that by far the larger portion of the lead which these mines Ornish is carried in wagons to Baltimore, is a strik- ing proof of the lucrative nature of the manufacture, and strongly indicates the benefit which in reference to this product, the pub- lic may be expected to reap from the extensive works of improve- ment which have been so wisely projected in this portion of the state.

The PUiister hanJcs in the North Holston and Walker's creek valleys, are another of the gifts which liberal Nature has bestowed upon this favoured region. The geological structure of the valley of the Holston is fraught with peculiar interest. After descending the northern slope of Walker's mountain, we come in view of the lofty limestone hills forming the southern boundary of the valley, and taking our station upon some elevated knoll, we see spread out betore us a scene of singular variety and beauty. Hills of limestone apparently arranged in rows, presenting conical and rounded out- lines of surprising symmetry and elegance, are stationed along the valley at nearly equal intervals. The rich verdure that spreads to

Ul

their very sammits, darkened hj the thick foliage of the sugar trees growing on their steep sides, softens the pictnresqne wildness of the hmdscape and conveys the idea of a soil of exuberant fertility. In the three first ranges of these hills the southern dip of the rocks in Walker's mountain and the intervening country is preserved, hut nearer to the river the limestones are seen dipping in the opposite direction. The anticlinal axis marked as occurring in a black slate is in the immediate vicinity of the plaister banks and the weUs from which the brine is obtained. This axis extends far to the east and west, and constitutes an important feature in the geology of this region. The plaister has been found along this valley and in that of Walker's creek which joins it to the east, for a distance of about 40 miles. Whether it extends in the latter direction heyond the termination of this line cannot as yet be known, — hut even should it not surpass this limit, the value of the deposit would baffle cal- culation. It does not occur as is sometimes supposed like the other rocks of the country, in a regular stratum having a fixed relation to the rest, but in masses of irregular form emhedded in dark coloured or ochreous clays. These masses are often of enonnous magnitude, and are either partially exposed at the surface, or covered with a variahle depth of earth. The excavation at M'Oill's quarry, which is nearly all in solid gypsum, is about 26 feet deep, 50 feet long, and 15 wide, and from horings it would appear that this solid mass of gypsum is more than 100 feet in deptn. In the neighhourhood of Buchanan's banks io the valley of Walker's creek, extensive expo- sures of it occur upon the surface, hut no very large excavations Lave yet heen made. Small openings have heen made at various other points, and thoufih the plaister has always been found in great abundance, the want of capital has prevented extensive operations from being attempted.

Some idea may be formed of the immense amount of gypsum contained in these valleys, from the fact that in the borings for salt water which have heen frequently made near the Holston, fragments of this rock have heen hrought up from the depth of 700 feet. In- deed, there seems to be every reason for helieving that it extends to great depths throughout a large portion of the region in which it is found — sometimes in masses of enormous dimensions, and some- times in small fragments and thin beds, mingled with ochreous clays and decomposed pyritous slate.

In speculating upon the origin of the gypsum of this region, the readiest explanation that suggests itself is that whicli ascribes its production to similar causes with those which gave birth to the gypsum of the Tertiary strata of lower Virginia. It has been in- cidentally remarked above, that pyritous slate occurs in fragments mingled with the gypsum and clay at the salt wells and other places. Supposing the valley to have once been filled with the debris of this slate and of the neighbouring limestones, we would have all the materials hrought together which are necessary for the produc- tion of the gypsum, while the slate after decomposition would be- come the clayey matrix in which the crystals would collect. This

view is rendered more probable from the oceurrenoe, even in the midst of the solid mssses of plaister, of fragments of the siHceooa rock which skirts the valley on the south. It is at least certain that the gypsnm has not been deposited here as in some other parts of the world, from the waters of Thermal springs holding it in sola- tion, since in that case it wonid be found disposed in layers as trar- ertin, and not in the irregular and scattereid condition which has been described.

The Brine 9pring$ constitate another valuable and interesting feature in the geology of the Uolston valley. Of the stratum from which the salt water is derived nothing certain is thus far known, although speculations have not been wanting on the subject. By some it has been imagined that salt in the solid form exists at a great depth below the level of the wells ; and this idea has been countenanced by the fact, affirmed by many, that granules of rock salt are sometimes seen in the water as it is pumped up. On this point, however, it may be remarked that these granules might have existed dispersed through the mass of a saliferous sandstone, as is the case in some other parts of the world. Be this as it may, the borings and wells have never penetrated to a stratum such as is usu- ally the repository of the salt water, but have gone through sncces- sive beds of blue and red clay and broken slate, all of them mingled more or less with plaister. TJie two wells now in use, Kings and Preston's, are each 212 feet deep. They are very near each other, and are thought to communicate beneath, and are situated a little to the south of the anticlinal line before noticed. The water, raised by a steam engine, is conveyed in wooden pipes to the furnace, two miles distant, where, after the crude impurities have been suffered to subside, by allowing it to rest some time in large taoks or reser- voirs, it is transferred to the kettles. Of these there are five double rows, each containing 100 kettles, making in all 500. 30,000 gallons of the brine are daily boiled down, yielding an average prod- uct of 1,000 bushels of salt, or one bushel for each 80 gallons. The sulphate of lime, which is almost the only impurity in this brine, for the most part adheres to the bottom of the kettles, and leaves the salt in a state of remarkable purity. At the same time sul- phurets are formed by the intense heat, which give a peculiar odour and flavour to the residual mass. No muriates of lime or magnesia exist in this brine. Hence it is free from littem, and dries rapidly in the air.

In the strength of the brine as well as its freedom from trouble- some impurities, these wells are scarcely excelled by any in tlie world.

While all the salt manufactured here is of a very excellent qual- ity, there are three grades, distingoished by different degrees of purity. These are,

1. The common salt, which is of a fine grain, dry, and not liable

to deliquesce in moist air, but is a little discolored.

2. The table salt, which is beautifully white and fine. This is . made by very rapid boiling.

8. The alum salt, perfeotljr pare, in thiu crystals of a satin las- tre. TluB i9 formed by slow orystallization as the kettles oooL Looking to the alnm salt now made in Kanawha, and the table salt above described, Virginia has just reason to be proud of the pre- eminence she has attained in this branch of manufacture.

Feeling deeply interested that the work, committed to my super- intendence, roajr progress with all the speed compatible with minute accoraoy both in regard to practical details and scientific dednc- tionfs I have endeavoured to form an estimate of the shortest period within which it appears practicable to complete it, with the provi- sions of the act passed by the last legislature. The complex and more precise experience of the intricacies of our geology, acquired during the last season's researches has led to a full conviction that with the present force it will not be practicable to bring the survey to a termination in a less time than twelve years ; that is, without sacrificing that exactness in research which must form its leading claim to confidence, and confer upon it all its utility.

Early in the season it became apparent that further assistance was required, both in the laboratory and field, and accordingly at my own cost and responsibility another aid was engaged, whose labours in both departments contributed mach to the advancement of the work. So that in fiict the amount of duty, performed dnr* ing the season, largely exceeded what could have been executed by the assistants authorized by the bill.

During the whole period of field work, the utmost activity has been exerted by all engaged in the task, and scarcely any suspension of labour has been permitted on account of rain and other unfavour- able conditions of the weather. For nine months the chemical in- vestigations connected with the survey have been steadily progress- ing, occupying my own attention daily, and giving employment to one of my assistants during a considerable part of the time.

Looking to the amount of work executed during the past season, both in the way of preliminary observation and detailed research, and guided by the knowledge, now obtained, of the extent of labour requisite for the completion of the survey, with a view to the accu- rate delineation of the geological details upon the map of the state, as well as the other important objects for which it was set on foot, I cannot hope, without a large addition to the corps of assistants, to progress with greater rapidity than during the past year.

But it is unnecessary to remark' that so tedious a prosecution of the work, and so long a postponement of the most valuable and in- teresting results which can only be properly made public at the conclusion of the survey, could not fail to prove injurious to the enterprise by diminishing the confidence of the public in the com- petency and activity of those employed.

In requesting of the legislature an augmentation of the annual appropriation for the worh it should be distinctly borne in mind,

that by sach an addition the total expense of the mrtey, inetead of being inereasecL, would be eoneiderably leeeened. Where several ex plorers can give their attention to the same formations in contigaoas districts, each has the advantage, under a systematic combination of efforts, of being directed in Ins enqoiries by the collective experience of the whole, and thas the investigations of each will be conducted with increased accuracy and expedition.

Another weighty inducement for adding to the number of the assistants to the survey arises from the expediency of making known as early as possible the resources which it will develope — a consid- eration at no time more important that at present, when the min- eral possessions of the state are attracting the enterprise and capi- tal of the community, and when plans of public improvement of great magnitude, to the success of which the survey must be more or less auxiliary, are enlisting general interest.

But besides this provision for an addition to the number of assistants, an increase will be required of that part of the appropri- ation set apart as a fund for the contingent expenses incurred in the operations ot the field and laboratory. Among the larger items demanding such a provision, may be instanced the expense of ex- ploring the rivers, creeks and inlets of the marl region by a boat properly constructed and equipped for the service, and of the trans- portation by an appropriate vehicle of the specimens collected in the numerous and distant localities examined ; and I may add the expense incurred for the apparatus and agents required in the chemical department of the survey.

It is conceived that the exigencies of the survey will be fully met by an appropriation which will farnish two additional salaries for assistants, and an increase of one thousand dollars to the portion of the fund destined for the contingent expenses. With the means of prosecuting the work thus enlarged, it is readily demonstrated from the experience already acquired of the advantages of com- bined exertion in the field, that the work may be brought to a ter- mination in one half the time necessary for its completion under the organization at present provided by law. Thus, while we as- sume twelve years for the time necessary with the means now at command, the entire expense of the survey will be about 60,000 dollars, whereas, with the ampler provisions above specified, it will probably fall short of 60,000.

Should the legislature accede to my views, and augment to this extent the annual appropriation, it will not exceed that contem- plated for the survey of the much smaller state of Pennsylvania, while it will be considerably less than one half of the sum devoted by New York to a territory of less extent, less intricacy of struct- ure, and less variety and fertility of mineral productions. I may be permitted to add, that in both of these states a separate assistant is furnished for the chemical department, though this aid it is not my intention to request.

There are other inducements to recommend the course here proposed, which, though less weighty than those just presented,

are not wanting in importance when it is considered that the repu- tation of our state for patriotism and love of science is not without an interest in the progress and results of the survey. Impressed with the maitude of the undertaking, it may not be unbecoming in me to remark that men of science in this country and abroad are looking forward to its completion with interest and curiosity. The responsibility thus incurred as the sdentifio investigator of the yet almost unexplored geology of our state, renders me still more de- sirous of obtaining such facilities for the execution of the work as will enable me to complete the numerous difficult researches, which it involves, ere the more interesting results can be anticipated by similar researches in some of the other states ; and it increases my anxiety to execute the task in a style of accuracy and minuteness, which, while it secures the permanent utility of the work, may, I hope, do credit to Virginia, advancing as she is in reputation for the encouragement of education and science.

Eepoet

or TBI PBOOROS or

The Geological Survey

or

The State Of Virginia,

For Tbs Year 1837.

Offiob ov trk Boaxd of Pubuo Wobxs,

Sib, Enclosed is a commanication to the house of delegates, which you will he pleased to lay before that body.

Very respectfully,

Your most obedient servant,

Dayid Oampbell, President of the Board of Public Works.

To the Honourable the Speaker of the House of Delegates.

Office of the Boasd of Pubuo Works, Ftruarg lOtb, 1888. To the House of Delegates.

I have the honour to transmit to the house of delegates a report of the chief geologist of the state, detailing the progress of the geo- logical survey in the year 1837.

David Campbell, President of the Board of Public Works.

Report.

Ih pursQanoe of the law requiring the prinoipal geologist of the state, annoallj to sabmit to the board of public works an acoonnt of the progress of the geological survey, I beg leave to make the follow- ing report :

The board are already aware of the unavoidable delay which occurred in completing Uie organization of the survey in the early part of the season ; a delay which as they know was occasioned by the difficulty of procuring suitable assistants to fill the vacancies existing in the corps ana to increase the number of my aids as authorized by the law passed at the last session of the legislature, enlarging the appropriation devoted to the survey. Notwithstand- ing these impediments, however, active explorations were com- menced by one division of my assistants in the tide water district of the state about the middle of April ; and early in June, our whole force was transferred to the region west of the Blae Ridge as the theatre of operations for the remainder of the season.

While thus allnding generally to the labours of the survey, I trust it will not be thought inappropriate to bear my cordial testi- mony to the zeal and efficiency with which my assistaots have exe- cuted the tasks respectively allotted to them, and to express the high gratification inspired by their laborious and careful investiga- tions. I would also take this occasion of tendering to the board my warmest acknowledgments for the interest they have manifested in the progress of the work, and for their prompt co-operation in all suggestions calculated to promote its success.

Adopting the method of exploration referred to in my report of last year, &e investigations in the tide water district have for the most part been conducted by means of a boat suitably fitted up and manned.

Aided by these facilities, the assistant to whom this department of duty was allotted, Mr. Charles B. 11 ay den, was enabled to pro- ceed with satisfactory minuteness in the examination of the shores

of the James river and its tribntaries, from its mouth as far up as the head of tide, inspecting the exposures of marl, claj, or other materials of interest presented on the banks of main stream on the rivers, creeks and inlets connected with it, at the same time col- lecting specimens for chemical analysis, or snch other examination as might be required. Occasional examinations were also made at yarioas points removed from the water, either with the view of ascertaining the continuity of deoosits, or of obviating the neces- sity of future exploration from the land side, where such exami- nation might be rendered difficult by the peculiar position of the locality.

Among the general objects of useful interest accomplished by the researches here referred to, may be mentioned a more precise determination than had hitherto been effected of the breadth of the Eocene, or green sand marl, where it is intersected by the James river, and the demonstration that no beds of secondary green sand, similar to those of New Jersey, are interposed between the Eocene and the coarse conglomerates, sandstones and clays which overlie tiie primary rocks near the lower falls of the James river, of the ex- istence of which, writers at a distance have more than once stated that some evidences had been discovered. On this head, I have now no hesitation in affirming that the concurring testimony of observations made in the course of the survey, on the Potomac, Rappahannock, Mattapony, Pamnnkey and James rivers, is conclu- sive against the existence within the region traversed by these streams of the New Jersey secondary, or any equivalent forma- tion.

Of the numerous specimens of marls, &c. collected in the course of this investigation, many have since been chemically examined, and the rest are now in the course of analysis. A table of the com- position of these and various other marls, examined within the last eighteen months, is herewith presented, under the belief that al though not strictly required in the annual report of the progress of the survey, such details are likely to prove useful to individuals in- terested in knowing the value of their marls, and are not of a nature to render it important that they should be reserved for the final port.

The exposures of marl upon the James river, though in some in- stances extending continuously for miles along the shore, are by no means commensurate with the deposits found at some distance in the interior. Low grounds, and banks of comparatively little alti- tude, occupy a large portion of either shore, for the most part filling up spaces whence the original deposit has been removed by denud- ing action, and rarely presenting any remains of the calcareous ma- terial, whUe along the banks of the minor streams, and on the declivities of the hills overlooking the lower levels, ample stores of this invaluable deposit are generally discovered. Nansemond river, Pagan creek and its branches, Lawns creek, Ohipoaks, Archershope, Ac, on all of which nearly uninterrupted exposures of the marl occur, illustrate the truth of this remark, and a similar observation

18 applicable to the shores of oar other principal riyers and their tribntaries.

Of the adyantages of exploring onr tide water riyers by means of boata the experience of the past season has famished satisfactory proof, and in yiew of the facilities thas proffered to oar future re- aearehea, by a suitable co-operation of inland and aquatic inyestiga- tions, I indulge the hope of bringing to a speedy completion that portion of the exploring duties of the suryey which relates to the lower district of the state.

Miocene Mabls.

LoeaUits: Ob9ervaHon$, Oarh, Lims.

Lajtoasteb.

OapL Ja's. Bobinson's, . . . Small fimgments of shell in a ferruginous

sand — green sand a tnu, 42.0

do. ditto, ditto, 87.5

Mr. Teiiey's, ditto, ditto, rather oompoct,. . . 80.6

do. Tellow— aluminouB— reen aaadatraoe,... 12.9

do Yellow— oonaisting ofiihelly flragments par- tially oemented— green sand a trace, 21.0

Mr. CabelFs, Shells deoompoeed and partially oemented, 42.0

do. ditto, .. 46.5

Mr. Callahan's, Yellow— iVitgments of shell in femious

sand — large grains of green sand in eon- sldorable quantity, 21.5

Mn. Palmer's, Yellow — small shells and ftagments — green

sand a trsoe, 82.9

Beqj. Walker's. Blue— green sand a trace, 18.0

Warner George's, Blue — shelly fhigments— green sand a trace, 14.7

CoL Palmer's, Light— oonfclomerated fhienii of shell- slightly compact — green sand a tnoe, 57.0 do. Shells decomposed and partially cemented,. 87.5

I>r. Jones's, ditto, porous, 86.8

Union mills, Yello>r — small shells in ferruginous sand, . . 28.8

do Lightr— quite comjiact — shells small— green

sand a trace, 62.5

CoL Phil. Branam's, Blue— tenacious— small shells— green sand

a trace, 21 .5

Mr. 8. I>owning's, Bluish— 10 or 12 per cent, of green sand.. . . 17.0

Braxton Tomlin's, Light — shelly fhigments — green sand a

trace, 82.9

6. Bownmg's, No. (4)— White— compact, with impressions

of shells, containing pebbles — specked with green sand, 67.4

Williamson Tomlin's, Blue— with small shells— green sand a trace, 28.8

WnrncoBKLAiro.

Sljatford Cliib, Bine— partially cemented— green sand a

trace, 44.8

BlCHHOND.

B. 0. Jeffries's, Bine— with small bivalve shells, 27.7

Wm. Bernard's, Blue— with decomposed ftvgmnts of shells 12.5

Mr. Saonders', Very compact— quite perceptibly specked

with green sand — very little shelly mat- ter, 9.0

LooalitUt. Ob9rvaiio$, Oarb. Lime.

Nobthukbeblaitd.

John Fulkfl's, Light blue-HnDall ftafiments of shell, 17.0

Walter Kioes, Very feiTuous ana compact— with frafr-

mcDts of shell — specked with green sand 6.8

Mr. Hedloy's, Tellow— green sand a trace, 21.5

Kmo Geukob. IdlonMflchadoxnm, Blue—a little green aand, 17.0

Mathews.

A. Braxton's, Shells conglomerated — oocasionally crystal-

liwd— light, 4.8

Warehouse Creek, Compact and semi-crystalline — ferrugous, 87.5

Middlesex.

Doctor Bowan's, No. (1)— Light— containing small fragments

of shell, 89.7

do. No. (2) — consisting of small bivalve shells

— green sand a trace, iS.8

Frospeot Hill Creek Shore, Comoeed entirely of sixuill shells intermixed

with sand — green sand a trace, 8S.5

B. Oaks's, No. (1 )— White — in small nodules — green

sand a trace, 78.4

do No. (2) ditto, 69.8

do No.(8) ditto, 76.1

do ditto, 75.0

do ditto, 73.8

Capt. Hailey's,. Licrht — containing fragments of shell — a

little green sand, 26.1

C. Braxton's, White — shells decomposed — green sand a

trace, 64.7

do. Shells loss decomposed and slightly ce- mented, 67.0

do ditto, 87.0

Col.Blaky's, White — decomposed shells and fragments

cemented, 82.9

Gloucestbb.

Mr. Pointei's, Yellow — clayey— containing a good many

ostrcas, 50.0

BoberU's Mill, Upper stratum — containing fragments of

snells, 84.0

Glouoestor Town, Shells decomposed and slightly cemented,.. 40.9

Mr. Billups's, White— shells decomposed — green sand a

trace,. 37.5

Mr. Thru8ton'R, Shells decomposed and slightly cemented,.. 60.2

Mr. R. Peraill'B, Fragments of shell cemented— green sand

a trace, 71.5

Bobins's Mill, Blue — tenacious — shells decomposed— green

sand a trace, 89.7

Jones's Mill, Upper stratum — white— shells very much

decomposed and slightly cemented, 51.1

Mr. Beverage's, Shells much broken — a good many partially

decomposed chamas — green sand a trace,. 57.9 Hill near Bobins's Mill,.. Consiitiug cliiefly of broken Augments of

shell,. 80.6

Mr. Beverage's, Small fragments of shell — greenish — green

sand a trace, 42.0

Gloucester Town ditto, richly specked with green sand, 41 .5

ZoeoKMat. ObtenMiHom, Curb, Lfme,

F OliTer'fl, Small frogmenta of shell, green sand a tnuse, 78.6

From the Boad between

Olouoester OouithouM

and Gloucester Town, . . Innodules, 51.1

Coorthouae Creek Brid,. Fraents of shell with sand intenuixed, . . 46.6

Mr. Billupa's, White— decooiposed and paitially cemented

— green Sana a trace, 61.1

Knro & QuxBx.

Piedmont, Bine— containing fragments of shell — green

sand a trace, 88. 6

do. lower bank, Bine, ditto, ditto, 22.2

Mr. Bagby's, White— shells finely decomposed and par-

tiaUy cemented, 80.6

do. Blue— containing fragments of shell, 80.6

Mr. Mann's, Liht— nodular i 78.4

do Wite — containing small fragments of shell, 80.6

Mr. Burton's, Light — shells deo(Hnpoeed — occasionally ce- mented, 85.2

Mr. Atkins's, Bmall fitigmentsof sheU, 76.1

Mr. Bylands, Shells decomposed, 46.5

Mr. Motley's, Blae — small shells and fragments— green

sand a trace, 14.7

Mr. PolUfd's, Blue — fragments of shell — green sand a

trace, 21.5

Mr. Gresham's, Light — fragments and decomposed shell

miffhtly cemented, 82.9

Mr. DnTal's, Blulsn— small fragments of shell, principally

ofthechama — green sand a trace, 78.7

Koro William.

Robert IliU's, Light— shells decomposed and very slightly

cemented. 54.5

do Light— shells decomposed and slightly com- pact, 68.4

do. hir fragments of shell in blue sand —

green sand a trace, 12.5

Mr. Edwarda's, Light— decomposed shells and fragments,. 76.1

Mr. EUet's, Blue— containing fragments of shell, 7.9

do. Light — tenaciooa — containing perfect sheila

and fragments, 26.8

Scotland Banks, Blue— containing fragments of shell, 7.9

Mr. Neal's, Fragments of shell intermixed with sand —

green sand a trace, 21.5

do ditto, ditto, ditto, 14.0

Essbz.

Dr. Minor's, Blue — rather compact— containing frag- ments of shell and small pebbles, 56.8

Mr. Hunter's, ditto, 1 7.0

Dr. Minor's, ditto, green sand a trace, 14.7

Mr. Bernard's, ditto, 84.6

Isle ov Wight.

Mr. H. Day's, Perfect shells and fragments — sometimes

cemented— green sand a trace, 76.1

do. Ferruginous rock marl— semi-ciystallino—

green sand a trace, 77.2

Mr. Saunders's, (2d stratum) — vellow— small friable frag- ments of snell— considerable green sand,. . 48. 8

LoeaMUt. ObtrvaUmu. Ceu. lims.

Mr. Saunders's, (8d strntum), small friable ftagments of sheU, 60.8

do. ditto, 42.0

James Pedin's, lAghi — iihella entirely decomposed— nodu- lar—ffreen sand a trace, 51.5

Day's Point, Blue — niable — micaceous and sandy, 7.9

O. tPurdie's, Bbells and fragments in a ligbt tenacious

clay — frequently rich in indurated casta of the ohamar-gnen sand a tnoe — some- times a fragmentaiy conglomerate, 71.5

do ditto, 62.5

do Conglomerate, ditto, 81.8

do ditto, 63.6

Mr. White's, A conglomerate of perfect shells and frag- ments— ferruginous and semi-crystalline

— very oompMt, 91.8

Mr. S. P. Jordan's, Very comminuted fragments of shell in a

ferruginous sand— green sand a trace, ... 5S.4

do. ditto 79.5

Merit Todd's, Light — rather tenacious— shells decomposed

— green sand a trace, 28.4

do. A conglomerate of small shells and frag- ments, intermixed with a ferrugioous

sand — tinged with green sand, 42.0

Bocks, Blue — arenaceous — very friable— contun-

ing a few small cythereas, 7.95

do. A ooaise shelly conglomerate — yellow— oc-

casiooaUy a cast of the chama, 78.4

Mr. Booth's, Of a very light yellow colour— containing

small fragments — frequently cemented,. . 64.7

do SheUs decomposed — concretionary, 71.5

John Y. Mason's, Small cythereas in a yellow sand, with a

few other shells and fragments — green sand a trace, 85.S

Naksemond.

Town Point, Ferruginous — consisting of small shells and

fragments, 67.6

2 miles above Town Point,. Ferruginous — consisting of small shells and

frannentB, 52.8

Mr. Keeliog's, Small shells and fragments in a light sand

— also fragments of the peoten — some- times conomerated, 75.0

do More ferruginous— containing fewer shells . 80.6

Below Dumpling Island,. . A conglomerate of fragments— quite com- pact, 85.2

do. .. finely comminuted shelly matter — deeply

tinged with iron 71.5

Mr. Gowper's, Ferruginous— consisting chiefly of fine frag- ments, 72.7

Near Suffolk, ditto, ditto, green,

sand a trace, 17.0

Upper shore of Nansemond nver (near the mouth),.. Small frainnents of shell, with perfect shells,

intermixed— ferruginous, 82.9

Point above Sleepy Hole ferry, Principallr chamas and crepidulas, inter- mixed with yellow sand, 48.2

Near Suffolk, Blue — containing finely divided shelly mat- ter, 22.7

LoealUi4ti ObtrvoMoM, Oarb, Lkne, Upper shore (near Sleepj

Hole ferry), Blae— containing fine and coarse fWigments

of small shells, 80.6

Col. Corbell's,. Small trsgments of shell — ferruginous, 62.5

do. ditto, 76.S

MiQ. Crocfker's, ditto, 64.7

do. ditto, 28.0

W. H. Goodwin's, ditto, 68.4

Mr. Phillips's, ditto, 80.6

Near Chucatock mill, ... . ditto, 82.9

Etjiabbth Cmr.

Hampton, Ferruginous — fhigments of shells with per-

tect shells intermixed, 71.6

do. ditto. 25.0

Subbt.

Mrs. Fanloons's, Yellow — consisting of decomposed shells

and fhigments — oocasionally slightl/ ce- mented, 64.6

S or 4 miles above Four

Mile tree, Fragments of shell in white sand— slightly

intermixed with green sand. 47.2

do. A yellow oonslomerate of shells and oasts,. 78.40

Near Four Mile tree, Fragments cu' shells and undeoompoeed

shells, 88.6

Mr. Organ's — Clermont,.. Yellowish white— fine and friable — occa- sionally concretionary. 71.6

Wakefield, Light — enells generally aeoomposed — a few

fragments in a white sand — green sand a

trace, 61.1

do Bluish--hells very much decomposed, 76.0

Douglas's, White indurated casts of chamos, 87.6

Clermont (liver shore),. . . Blue — largely intennixed with green sand

shells flnelr decomposed, 10.2

Upper Chipoke Creek, A calcareoilioeous conglomerate — very

compact— containing frigments of pec-

tens and casts of pemas, 55.6

nail fragments or shell in sand — a good many cnamas — quite richly specked with

Stithes, Small fragments or shell in sand — a good

green sand, 42.0

do ditto. 88.0

Mver shore (above the mouth of College creek,) Conttisting of fragments of the ohama in a

liffht Mind, 44.8

A. C. Jones's, Shells and fragments in a light sand — inter- mixed with green sand, 68.2

PmHCE Geobgx.

Coggin's Point, Small shells and fragments in a yellow sand

— green sand a trace, 28.4

Mr. Prentice's, A great variety of shells in sand, 58.6

Evergreen, Fragments of shells in a light sand, 82.9

Tarbay, ditto, ditto, 19.4

Jambs Crrr.

King's Mill, Chiefly fragments of the chamar— intermixed

with green sand, 56.8

Wabwick.

Mr. Wynn's, 75.0

Eocene Mabls.

LocaUUea. Obaervatiotu. Ckwt. £dm

Cbabues Citt.

flening Creek, Liiht — shells generally deoomposed — Blight-

ly compact — intenmxed witn green sand,. 87.5

do ditto, 50.0

Prikce Geobge.

Coggings point, Yellow — friable — no traces of shells — a lit- tle green sand, .7

do. ditto, 87.5

Mayoox, Tcllow — no traces of shells — in nodules —

siliooous, 4SLS

do Light — compact— contuning impressions of

shells intermixed with green sand 78.8

do (Mouth of Powell's creek ditto, 42.0

Chestebfield.

Mrs. Cocks' s, Indurated — containing impressions of shells

and small decomposed shells intermixed

with green sand, 60.2

do ditto, 76.1

Hekbioo.

Mr. Organ's, (Upper plantation) — liht— fine and fHable

—out slight traces ot shells — a little green sand, 47.2

Deep Bottom, light jrellow— indurated — homogeneous —

contaming casts of shells— slightly mica- ceous, 54.5

The scene of exploration in the upper portion of the state where the entire force of the corps was actively engaged, from June ontil late in the autumn, embraced all the region lying between the Blue Ridge and the first escarpment of the coal-bearing rocks of the Alleghany proper. Dividing this extensive field into three portionsi, by convenient transverse lines, an assistant, with such equipments as were thought necessary, was allotted to each district; Mr. Charles B, Hayden being placed in the northern, Professor J. B. Rogers in the middle, and Professor W. E. A. Aikin in the southern subdi vision. Pursuing a common system of investigation in all te districts, we commenced our enquiries by numerous observations along the western declivity and flank of the Bine Ridge, chiefly with the view of conclusively determining the relation of the rocks of that mountain and of the valley to the west, a problem of some difficulty, and of which our previous exploration had not furnished a satisfactory explanation. Next, by a series of transverse lines, extending from the Blue Ridge across the valley, and numerous ranges of mountains further west, we proceeded to ascertain with more precision than had yet been done, the law of succession of the various rocks composing this wide belt of country, noting their dip, arrangement, character and mineral contents at every step, and

tracing geological profiles of onr route. In this portion of oar labour I may be allowed to state, that the fatigue and privation to which we were frequently exposed in our travels, among rugged moontaina, and by unfrequented and sometimes almost pathless routes, were not a little lightened by the animating influenoe of scenery, at once wild and beautiful and sublime, rich in subjects for the artistes pencil, and pregnant with lessons for the geological enquirer.

Guided by the precise knowledge thus attained, of the general stmoture of tJie regions we proposed to investigate, we enter upon the detailed examinations necessary to a proper developement of the mineral resources of each district, and to the introduction of geological delineations on the state map.

Following the longitudinal bearings of all the strata, tracing them through the valleys or along the flanks and summits of the mountains, marking their boundaries and their changes of extent and structure, and carefully pursuing every indication pointing to useful economical results, we have been enabled, through the active labours of this season, to accumulate a large body of accurate and valuable details, illustrating the resources as well as the geological structure of extensive portions of the region in which our enquiries were pursued. Indeed, such has been the success of the plan of in- vestigation adopted, that but for numerous errors of the state map, of which we have had glaring and sometimes ludicrous illustrations in the course of the season, I would feel myself prepared to give a visible' form to our results by a systematic geological colouring of many of the counties, both of the northern and middle, as well as important portions of the southern district.

From the vast extent of the region in question, the intricacies of geological structure occurring in many parts of it, and the natural obstacles to exploration arising from the singularly rugged topog- raphy of its mountainous portions, it will at once be seen that, with the force at onr command, the labours of a single season, however active and judiciously bestowed, could accomplish but a part, and that by no means the larger portion of the researches requisite for a minute knowledge of its structure, and its peculiarly valuable mineral contents.

Aware, as the board must be of the nature and extent of the impediments referred to, they will be enabled better to appreciate their influence upon the progress of our researches, from the con- sideration that in geological explorations, conducted in such a re- gion, satisfactory results are rarely to be attained merely by the in- vestigation of exposures occurring along a highway, or in positions equally easy to be reached. The rugged valleys, the craggy cliffs, the steep sides and rocky summits of the mountains, often furnish the most valuable guides to a knowledge of geological structure. Forsaking the path of the ordinary traveller, and plunging into the wildest and most unfrequented districts of the region he is explor- ing, the geologist is called upon to take the hunter of the mountains for his guide, and to thread the forest, to follow the rocky channel

of the stream, or to climb the towering peak in search of farther lights to aid him to sure and valnable determinations.

Amid the wild eihibitions of dislocation, frequently met with in the mountains of this region, many interesting and useful facts hare been observed, while the most striking features of scenery neces- sarily associated with the geological phenomena displayed, have been noted as suitable subjects for graphical illustration at some future day, when together with accurate geological sections illustrative of all the interesting points of structure in our state, it is my earnest wish to be enabled to present, from the pencil of a practised artist, a series of drawings combining similar instructive characteristics with the more attractive charms, imparted by a faithful delineation of the beautiful and imposing scenery in which our state so remark- ably abounds.

Without entering into a detailed account, of either the general or minute investigations completed or in progress in this region, I would call the attention of the board to some of the enquiries prose- cuted, and some of the results determined, in each of the three districts in question.

In the northern and middle districts, the interesting fact has now been conclusively ascertained, that the extensive beds of sandstone composing the hills along the western flank of the Blue Ridge, and sometimes lying upon the declivity of the mountain, or resting in lofty peaks near its summit, are snbiacent in geological position to the great limestone formation of the valley; and that from the peculiar attitude in which this rock is found, and the marine and littoral impressions with which it is sometimes crowded, it marks out the ancient coast-line of a wide spread sea, beneath whose waters the vast extent of sedimentary rocks stretching westward from the ridge, were successively deposited. This rock has in many places been found to contain beds of iron ore, though in general of inferior quality to that met with in the limestone of the vdley.

The Massanntten ranges, indading the Massanutten proper, the Middle, Three- Topped, Peaked and other mountains, as well as the subordinate hills, and the intervening vaUeys, have been the subject of careful study ; and a clear knowledge has been attained of the structure and contents of nearly the whole region, from the Peak, near Keezle Town, to the northern termination of these mountains, opposite Strasburg. Amid the indications of extraordinary violence, marking the rugged scenery of this remarkable region, the most beautiful symmetry in the arrangement of the component strata of the hills and valleys has been found to prevail ; leading to interest- ing practical conclusions as to the extent and continuity of the use- ful mineral productions which it contains.

The heavy beds of valuable iron ore, of which extensive ex- posures have already been brought to light in supplying this mate- rial to the neighbouring furnaces, have been traced for great distances along the borders of the slate, subjacent to the massive sandstone, of which the principal ridges are composed ; and an ore of still su- perior quality, associated with the red and variegated shales, higher

ap in the geological series, has been discovered in many parts of the Big and Little Fort Talleys, exposed in layers, which, from the extent of the line of their outcrop, are probably continuously associ- ated with the strata, to which they appertain. Looking to the rela- tion now proved to exist between the rocks of this region, and the limestone of the valley on either side, the hope that has from time to time been entertained of the discovery of coal within these monntains, is to be looked upon as entirely without grounds ; beds of this material have in no instance been discovered in strata so low in our geological series as are the slates and sandstones of which this region is composed, nor have any indications of it ever been observed in these rocks either in Pennsylvania or this state. In thus prominently and decidedly announcing this negative result, it is scarcely necessary to remark, that however opposed may be such a oonciasion to the wishes of those who fondly imagine that every variety of mineral treasure is to be found in every portion of our mountain districts, much good is likely to result from a determina- tion calculated to prevent explorations which could only lead to disappointment, and perhaps terminate in serious loss.

The wide belt of slate forming the basis of the sandstones of the Massanutten ranges, and extending in the same general direction into Maryland on the one side, and into the southern parts of Um valley on the other, has been traced throughout a considerable por- tion of these districts, and its boundaries carefully noted down ; at the same time that the iron and manganese ore, which it contains, have been attentively examined.

Observation has also been directed to the numerous varieties of limestone forming the great agricultural wealth of our valley coun- ties, in these districts as well as further south. Additionid speci- mens have been collected with a view to the systematic arrangement of the several distinct species of this rock, under the heads of sim- ply calcareous, or magnesian, or hydraulic, according to the results of chemical examination. The iron ores associated with these strata, have also been examined at various points, and specimens reserved for similar practical objects.

In that portion of the two districts in question, extending from the western boundary of the valley limestone to the escarpment of tlie Alleghany rocks, research has been more especially directed to the region lying west of the Oacapon river, and of the Great Shen- andoah mountain, although numerous sections have been made crossing the intervening belt. In the adoption of this course, I have been influenced by the results of former observations, leading to the conclusion that the low ranges flanking the valley to the west could never be satisfactorily investigated until the structure of the region beyond was clearly understood. From the very remarkable geological appearances generally presented, where the most eastern of these ranges meets the valley rocks, it became apparent during the last year, that the usual and otherwise invariable order of suc- cession of the several members of our series of rocks was here vio- lently interrupted, and that the limestone, one of the lower mem-

bers of the group, was brought in contact with strata nearly ap- proaching in position to the carboniferoaa alatee and sandstones so widely extended over the region westward of the Alleghany. This line of fault, of which indications are to be met with at most of the gaps immediately west of the valley, appears to extend with but little interruption throughout the whole length of the state, and presents a striking illustration of the stupendous violence of the forces by whose agency the strata of the valley and of the parallel mountain chains lying to its west, have been caused to assume the positions which they now exhibit. Without entering more into detail in regard to this interesting and extraordinary feature in oar geology, it will be apparent to the board, that repeated and careful observations made at various points along the line of dislocation, must be requisite to a sure determination of the point in the geo- logical scale to which the strata thus abutting against the valley should be referred. And the more caution is required in this inves- tigation as these strata have in many places been found to contain an anthracite or semi-bituminous coal, and the probability of its continuity or available importance, might in some degree depend on the opinion formed of the rocks with which it is associated. While from these considerations, I directed examination chiefly to the region situated more to the west, so that in another season we might approach this tract of more perplexing difficulty witli the useful lights afforded by a clear knowledge of strata whose connec- tion we could trace with them, attention has been incidentally be- stowed at several points upon the coal-bearing rocks adjacent to the valley. The interest naturally felt in the existence of a deposit of coal appearing at many localities along the line in question, and from its vicinity to a populous and thriving region, invested with peculiar importance, renders me reluctant without much more detailed examination than I have yet bestowed upon it, to venture upon an opinion as to its actual extent, or to affirm positively its position in the geological series, as compared with the anthracite of Pennsylvania, or the bituminous coal of our western counties. This much, however, I may with propriety declare, that thouch undoubtedly far less extensive than the formation in Pennsylvania, its almost unquestionable continuity in some districts, as for in- stance, in Montgomery, Wythe, &c. over great distances, and the available thickness and good quality of the coal where exposed, lead to the opinion that it is destined at some day to become an impor- tant item in the resources of the surrounding region. I may vent- ure further to add, though reserving this opinion to be corrected by future observations, that ft'om the examinations thus far made, the rocks with which this coal is associated would appear to occupy a lower place in the series than the bituminous coal measures of the west, or the shales and sandstones of the anthracite of Pennsylvania; and that they will probably, in most oases, be found to refer them- selves to the most inferior member of the group. In what is here stated in relation to our anthracite and semi-bituminous coal, the board will understand me as not confining my remarks to the

two diBtricts of wbioh I am at present treating, bnt as designicg them to apply also to the soathem district.

la pursoing oar researches to the west of the belt of which we have just been speaking, the general arrangement of the strata, which, with the assistance of Professor U. D. Rogers, I had been enabled to establish daring the preceding season, as applicable to Virginia and Pennsylvania, and which he has since ascertained, with some modifications, to apply to New York/ was found to fur- nish an invalaable guide. Directed by this arrangement, of which a descriptive account will hereafter be given the explorations in Hampshire, a part of Moifan, Hardy, Pendleton, Bath, Pocahontas, Alleghany, and portions of Greenbrier and Monroe, were condncted with great minuteness of detail and with the most satisfactory re- sults. Without entering into the particulars of our investigations, I would mention as iUostrating the activity and success with which our researches were carried on, that a complete and accurate ac- quaintance with the structure of a large part of the region referred to has been attained, and with the materials now in hand, the space occupied by the several rocks throughout a wide area, could be delineated in geological colours on the state map. In these minute enquiries, as necessary data for obtaining valuable practical results, the various modifications of geological arrangement occurring at different points of each valley and range of mountains were care- fully traced out.

Among the facts of economical interest developed in the coarse of these researches, may be mentioned the determination of the almost uniform occurrence of a peculiarly valuable description of iron ore in connection with a certain member of our series of rocks, frequently displayed for great distances along the sides and summits of the ridges in this region. This ore presents itself in layers ar- ranged parallel with each other, and separated by thin strata of a reddish shale. Though rarely occurring in single beds of great thickness, the multiplication of small seams, exhibited at numerous points, indicate the abundance in which it might be procured, while the friable and yielding condition of the enclosing material would greatly facilitate its removal from the places in which it is embedded. In the Knobly, New creek, Patterson's creek, Capon, North fork, Prop's gap. South branch, Warm spring, Bullpasture and Back creek mountains, and in fact in a great minority of the more considerable ridges of this region, the presence of this ore has been recognized either at isolated points, or continuously for a length of several miles, exhibiting in alt cases the same associated shales, and occu- pying an invariable station in the geological series. Of the extraor- dinary value of this ore, the experience of the furnaces in Pennsyl- vania, where it has recently been bront into use, furnishes the most conclusive evidence. And since the discovery of its admi- rable adaptation for the furnace, it has been keenly sought after, and seams, which if of a different material, would from their thin- ness have remained unnoticed, have not only been diligently but profitably worked. In alluding to this important fact, the board

will permit me to sajr, that it is not a Httle gratifying to me to have reached a result, thus illustrative of the advantages of the mode of research which has heen porsoed, and of the ntility of that sjatem- atio delineation of the strata, which it is hoped, will form one of the crowning works of the survey.

Without attempting to particularize economical or general re- sults, it may be proper to add that the limestones, frequently de- veloped to a considerable extent in this region, giving fertility to many of the long and narrow valleys, and providing a rich naturd pasturage on the broad and undulating tops of many of the mount- ains, has been the subject of attentive observation and analysis. It is a fact of interest, though as yet but little known or appreciated, that owing to the extent to which one of these calcareous rocks is frequently spread out upon the summits of some of the more mass- ive of these ridges, soils of a highly productive character are often to be met with in positions where it might be supposed they would be least likely to occur ; and the traveller, who has bestowed no attention upon the geological structure of the mountains, cannot fail to experience the most gratifying surprise, when, after toiling over hills of slate, and climbing a rocky defile over fragments, and amid impending clifTs of sterile sandstone, he finds himself suddenly on the margin of an undulating plateau of shales and limestones, in an open and in some cases a cultivated region. On the Knobly, the Prop's gap, BuUpasture and other ranges, these tracts, of high agri- cultural value, are oontinuonaly exposed. I may here add that the occurrence of this limestone in immediate contiguity with the red shale, of whose valuable contents I have already spoken, invests it with additional importance, and the existence in it of calcareous bands, capable of furnishing an excellent water cement, specimens of which are now in progress of analysis.

In the south-western portion of the region to which we are now alluding, commences an extensive tract of calcareous shales and sandstones, which, expanding in breadth as it stretches south and west, constitutes the rich agricultural and grazing regions of Poca- hontas, Greenbrier, Monroe and Giles, and bestows productive soils upon the counties lying in the same direction, as far as the south- ern boundary of the state.

Of this important member of the series, Pennsylvania is almost entirely deprived, and the developement is comparatively inconsider- able, even in Virginia, until we reach the region just referred to, where its great expannon renders it a prominent and happy feature in the geology of the state. Although in the middle and southern districts, especially the former, the character of these shales and limestones have Jieen carefully examined, and numerous specimens of the latter analyzed, much research yet remains to be bestowed upon them, both in connexion with their agricultural and economi- cal value, and the origin of those medicinal ingredients which have given such merited celebrity to a number of our watering-places situated in the midst of these strata, and forming not one of the least of the blessings attendant upon the geological developement of

this portion of our series of rocks. The existence in this region of a highly valaable form of iron ore bearing some analogy to that last described has been ascertained by observations at several points, and snggestd the propriety and probable importance of further re- searches on the subject.

Of the progress and results of our researches in the southern district, some opinion will already have been formed from the gen- eral statements above submitted in relation to the other two subdi- visions. It will be observed, however, that difficulties of a peculiar kind have attended our investigations in this district. The particu- lar succession of limestones, slates and sandstones, forming the geo- logical series to which the structure of the northern and middle dis- tricts has been in all cases satisfactorily referred, cannot be applied in elucidating the arrangement of the strata in the southern district, without considerable modification. Moreover, certain peculiarities of structure evidently related to the new direction of the Blue Ridge, and the parallel ranges north-west of the valley, while they increase the interest, augment the difficulty of the problems here offered for investigation. While, therefore, a large share of atten- tion has been devoted to the examination of objects of economical importance, whenever they have been presented, much research has been necessary to remove the obscurity in which the geological order of the strata of this district was involved, and to arrive at sure conclusions as to the relations borne by them to the n>cks of which the other districts were composed. In tracing the modifica- tions of several of the members of the series, as they are prolonged in the south-west, and unfolding the nature and precise order of the strata as displayed in that portion of the state, considerable progress has been made, but further research is still required in regard to several important features in its geology* The board need not to be informed that it is by such researches, far more than by the mere examination of mineral localities, or the tracing of exposure of ma- terials of economical value, that the useful objects of the survey are to be promoted. From the general uniformity with which particu- lar ores or other useful minerals are atsociated with particular mem- bers of the series of rocks, as already illustrated in the case of the valuable iron ore of Hampshire, Hardy, Pendleton, and other conn- ties, it must be apparent that in tracing any individual rock through- out its course, and much more in developing the general order in which the strata are arranged, results of the highest utility are dis- closed, illustrating equally the resources of all parts of the region investigated, and furnishing the only safe guide to the more minute examinations which are to form the basis of individual enterprise.

In pursuing these leading objects, a great number of transverse lines have been explored, extending in many Instances entirely across the region, and including on the east a large portion of the rocks of the Blue Ridge, and the Pilot, Poplar Gamp and Iron mountains, while numerous lines of observation connecting them have served to throw light on the structure of the intervening belts of country. As evidence of tlie extent and minuteness with which

these preliminary examinatians have been condaoted and as indi- oatiDg some of the important general resalts to which they have led, I would refer the board to the approximate profiles, twenty in nam- her, exhibiting the strata of this region, either thronghont its entire breadth, or in particular portions, where more precise inyestigation was suggested by the peculiar importance or the difficulty of obtain- ing a clear knowledge of the geological structure involyed. With these sections, amid the various determinations not embodied in them, as our guides, the operations of a future season will be greati j facilitated ; and I feel assured that the obscurity yet remaining, in regard to the structure of some portions of this curious and affluent district of the state, will be satisfactorily removed.

At the same time that these more general and fundamental en- quirii s were in active progress, much attention was devoted to the examination of the known localities of iron ore, lead, gypsnro, salt and coal, and to the further developement of these materials, by carefully tracing the strata with which they were found to be geo- logically associated. Of the important economical results to which these general as well as detailed explorations, when brought to a close, are likely to develope, it would of course be inexpedient as well as premature now to speak. I may, however, be permitted to remark, that our investigations thus far have tended to confirm the favourable impression uready existing as to the extent and variety of the mineral resources of this region. As conspicuous among the future sources of wealth and prosperity throughout this region, I may be again permitted to call the attention of the board to the ex- traordinary abundance and excellent qualities of its iron ores. Be- sides innumerable exposures of this material in various parts of the great limestone valley, and among the ridges lying to the north- west, I would particularly bring to notice the very extensive range of deposits which, commencing at Mack's run and pursuing a course parallel to the Poplar Camp and Iron mountains, within from two to four miles of their base, continues to the southern boundary of the state. In this region, from two to three miles in width, this ore is found in the fianks of the calcareous ridges in massive beds, fre- quently enclosed by walls of limestone, and usually of a quality ad- mirably adapted to the uses of the furnace. There is, perhaps, no other portion of the great hmestone valley, either in Pennsylvania or Virginia, so bountifnlly supplied with this material in so avail- able a shape, and none in which this valuable resource has been more indolently improved. A deep sense of the almost unrivalled importance of the iron ores of this and the other districts referred to, must excuse the repeated allusions of which it has been the theme, especially when it is considered, that from the frequency of the occurrence of this material in various parts of the state, the high interest which ought to attach to snch a possession does not appear to have been adequately felt

In regard to the anthracite or semi-bituminous coal exposed at various points in the district here referred to, it would be premature in the present stage of our investigations, to present any further or

more decided yievs than have been already submitted while ollad- ing to the peculiar strnctiire of the ranges on the western margin of the valley. I would, however, observe that much has already been done in ascertaining its geological position and economical charac* ter, both as presented under the circumstances alluded to in the Brash or Little Walker*s mountain, and under somewhat different relations in the Catawba mountain and the Peaked knob of Drapers mountain, as well as in some other localities in which small expos- ures have been discovered.

Of those peculiar and inestimable funds of mineral wealth, the salt, plaister and lead of this region, I feel justified in saying that the investigations bestowed on them during the past season, have served to impart even higher ideas of their importance than had al- ready been formed, while I would add, that the enquiries relating to their extent are still in progress, and cannot be completed without much additional exploration.

In thus alluding to the economical bearings of our researches in this district in the course of the last season, I would call the atten- tion of the board to a feature in its geology of great agricultural in- terestf and . which, though locally well known, appears to be but impeifecUy understood or appreciated by those residing at a dis- tance : I allude to the large extent of surface occupied by calcareous rooks in that portion of the region lying to the north-west of the Gap or Walkers mountain. Without attempting to detine the ex- tensive valley and mountain tracts, thus prepared liberally to re- ward the toil and enterprise of the husbandman, it will be sufficient to remark, that from this cause large portions of Giles, Tazewdl, Russell, Scott and Lee counties, present a surface happily adapted to agricultural industry, combining the rich spontaneous growth of mountain pasturage, with the generous products of a lowland soil of unusual fertility. Nor can I, while alluding to these interesting features in the structure of the south-west portion of the state, avoid expressing the earnest hope, that in the progress of those great schemes of improvement which are daily giving fresh anima- tion to the hopes of patriotism throughout Virginia, effectual meas- ures wiU be adopted for giving access to these and other productive regions now lying uncultivated, neglected, and almost unknown. And looking to the influence which these facilities of communica- tion will exert, may we not indulge the pleasing anticipation, that ere long the crowd of our emigrating fellow-citizens, now yearly thronging the great highways leading to the west and south, will be invited to spread the blessings of agricultural enterprise and skill over the rich valleys and mountain sides of their native land.

It will be apparent, from the preceding remarks, that the deter- mination of the order in which the sever members of our geologi- cal series are arranged throughout the region west of the Blue Ridge, constitutes one of the most interesting and valuable results yet developed by the labours of the survey, not only leading to curi- ous and important conclusions of a strictly scientific nature, but fur- nishing a sure guide to researches of economical value. In this as-

peot, therefore, and with the view of illatrating nntnerons allanona in the present report, as well as of affording usefcd practical sag- gestions to those who may be interested in developing the resources of the region in question, I feel assared that the board will not deem it uninteresting, in this place, to offer a brief description of the sev- eral important members of the series of rocks occupying the region west off the Blue Ridge, illustrating their economical character in connexion with their structure, position and extent.

Restricting our view to that portion of the region lying between the Blue Ridge and the coal-bearing rocks, forming the eastern es- carpment of the Alleghany, which lies northward of the New river, we find that the whole of this vast territory is made up of sand- stone, limestones, slates and shales, arranged in an invariable order of superposition, and capable of being readily arranged in a geologi- cal series, consisting of eleven distinct and weU characterised mem- bers.

In regard to the continuation of this region through the south- west portion of the state, as formerly remarked, important modifi- cations in some of the members of the series are found to occur, which although already to some extent traced out, have not been so completely developed as to warrant a full and determinate descrip- tion of them at this time.

Throughout the whole of the vast area extending from the Blue Ridge westwards, the strata are for the most part of oceanic origin. In each of the eleven members of the series, as well as in the coal- bearing rocks lying still further west, the remains of marine ani- mals are frequently to be met with, and in many instances, their relics constitute a large portion of the substance of the rock ; thus confirming the inferences derived from the nature and structure of the materials of the strata themselves, and clearly attesting the fact of their having been deposited along the shores and at the bottom of a wide-spread ocean.

As already remarked, the position and character of the sand- stone, resting in many places upon the western declivity of the Blue Ridge, and forming broken ranges of hills along its base, roost distinctly and beautifully mark out the coast line of the ancient sea, while the peculiar impressions hereafter to be described, as so abundantly exhibited upon and throughout this rock, afford a strik- ing confirmation of its littoral origin, or at least of its having been deposited in shallow water, and near the margin of the sea.

The view thus presented of the oceanic formation of the strata of this portion of the state, and the facts above referred to, illus- trating the eastern boundary of this ancient sea, though franght with deep interest when considered merely in relation to the geol- ogy of our own territory, assume a far higher importance when as- sociated with the more ample investigations and developments of Professor H. D. Rogers in Pennsylvania and New York. Studying the various members of the geological series, as they appear through- out large portions of those states and Virginia, identifying them as they are exhibited in the region of our great lakes, and in parts of

the TtQej of the Mismasippi, he has traced oat the ancient coast line of the vast ooean, beneath which they were snccessively deposited, following its great inflexion as it bends westward along its northern margin — and thos connecting in one comprehensiye and sublime generalization, the entire geological system of a large portion of oar continent, and clearly demonstrating the operation of similar geo- logical canses over an extent of territory, and with a regnlarity of law of which there is perhaps no equally remarkable example in the whole field of modem exploration.

Ik$cnption of ikt $everal Memhen of the Geological 8erU$ belonging to the Region West of the Blue Hidge.

Designating each member or groap of rocks, by the number ex- presring its position in the series, the lowest being indicated by No. 1, and describing them in the ascending order, according to the law of superoosition by which they have been found to be invari- ably arrangeo, we will commence with

(No. 1.) — This rock, or group of rocks, which is frequently ex- hibited in extensive exposures along the western side and base of the Bine Ridge, more especially in the middle counties of the valley, is usually a compact, rather fine-grained, white or yellowish grey sandstone. Where resting on the declivity of the ridge, it presents a gentle inclination to the north-west — while the subjacent and more ancient strata of the ridge, in almost every instance, dip steeply to the south-east. In Page, Rockingham, Augusta and Rockbridge counties this rock forms the irregular and broken ranges of hills lying immediately at the foot of the main Blue Ridge, and sometimes attaining an altitude little inferior to that of the principal mountain. A level region, sometimes of considerable breadth, and strewed profusely with the fragments of this rock, in general intervenes between these rugged hills and the first expos- ures of the valley limestone ; thus indicating at once the extent oi the formation, and the violence of the forces to which it has been subjected. In many instances two, sometimes three, ranges of hills are interposed between the limestone and what may be considered as the termination of the rocks of the Blue Ridge, in which case the sandstone of those nearest the ridge exhibits peculiarities of com- pontion and structure which distinguish it from the rock found in more remote positions. Talcose and micaceous matter make their appearance in it; its specific gravity is increased, and a jointed structure is developed to so great a degree that it becomes difBcult to recognize its true plane of dip. Of the innumerable cross joints by which it is subdivided into somewhat rhombic forms, the most conspicuous are those running N. £. and S. W., and imparting to the rock, though nearly horizontal in its bedding, the appearance of a steep soutii-easterly dip. This micaceous ana talcose variety is sometimes found in the same hill underlying the more purely silice- ous rock.

The latter, in nearly all the exposures from the Balcony falls to

Thornton's gap, as well as in yarions other places, exhibits yioe, fucoidal and zoophytic impressions on the surfaces of bedding, to- gether with innamerable markings at right angles to the stratifica- tion, penetrating in straight lines to great depths in the rock, and from their freqaencj and parallelism determining its cleavage in nearly vertical planes. These markings are of a flattened, cylindri- cal form, from ith to ith of an inch broad, giving the sorfiaoe of the fractared rock a ribbed appearance, and resembling perforations made in sand which have been sabseqnently filled up, without de- stroying the distinctness of the original impression. Precisely edmi- lar markings are found in great abundance in the white compact .sandstone occurring at a higher point in the series, associated with numerous unequivocal impressions of fucoides.

The extent to which tnese sandstones are developed is compara- tively inconsiderable in the southern and northern counties of the valley, and their structure and composition are in many respects materially changed.

The jointed structure so thoroughly pervades them in these dis- tricts, as to render it extremely difficult to ascertain the dip ; but in numerous instances, especiaUy in Floyd, Montgomery, Wythe, &c. the bedding is nearly vertical, dipping in most instances in conform- ity to the rocks of the Blue Ridge, that is, to the south and east. In no portion of the region occupied by these rooks can their nature and relations be more satisfactorily studied than along the eastern margin of Augusta, Rockingham and Page counties. In many parts of this district, not only the bold ranges of hills skirting the western base of the Blue Ridge, but sevend of the lofty peaks and ranges lying upon the western slope of the main mountain, are compo9d of these materials. At Mount Torrey, and Turk's, and Simmons gap, as well as at numerous intervening points, this arrangement is strik- ingly observed ; and as already remarked, tlie sandstone thus resting upon the breast, and near the main ridge of the mountain, presents a gentle but uniform inclination to the north-west. At Calloway's rocks, and the Black rocks, lying north of Turk's gap, stupendous exposures are to be seen ; the rock in the two former instances be- ing remarkably hard and sonorous, of a slightly ferruginous hue, and cleft by smooth joints at right angles to the bedding, which is nearly horizontal, thus presenting the appearance of huge blocks of masonry piled in massive rectangular columns on the top and sides of the ridge, where the exposures occur. In the knob, which tow- ers to our left, as we commence our descent towards the valley along the Turk's gap road, the impressions or markings above de- scril are abundantly exhibited. This vast mass of outlying sand- stone, presents a gentle western inclination, while the rocks upon which it rests are seen dipping steeply to the south-oast. These minute details in regard to the character x>f the rocks in question, together with the references to particular exposures calculated to illustrate their structure and arrangement will, I trust, not be deemed unimportant in a geological point of view, when it is con- sidered that they relate to the first member of that vast series of

strata whose law of saocession we have proposed to elooidate, and that they mark out the oommencement of a train of geological operations, which in their progress have given origin to the rockj strata of a large portion of the territory of the United States.

At the junction of these sandstones with the limestone of the valley, depoeits of iron ore are occasionally to he found, which, al- though sometimes of a good quality, is often hlended with oxide of manganese.

(No. 2.) — The second member of our series, is the valley lime- stone with its associated slaty and siliceous bands. Without enter- ing into specific descriptions of all the marked varieties of this rock, occurring at various points within the valley or elsewhere, it will be sufficient at this time to refer to some of its more distin- guishing features, economically as well as geologically considered. Varying in colour from the deepest blue, approaching black, to a light grey, and sometimes an almost pure white, presentiug every modification of texture from the uniform and compact grain of a marble, susceptible of the highest polish, to the soft, slaty, or harsh arenaceous structure, and exhibiting a composition equally diversi- fied, varying from the pure calcareous spar to the siliceous, tlie aluoiinons, and the magnesian limestone, it is obvious, that no one general description will be applicable to its numerous modifications. For a mineralogical and chemical account of those varieties, princi- pally interesting in an economical point of view, I would refer to the observations and chemical results embraced in my last yearns report. Numerous analyses have been made both before and since that time, and investigations on the same subject are still in progress.

With the view of affording further detailed information in regard to the constitution of these rocks, so important in their application to agricultural and architectural parposes, the following additional analytic results may here be usefnlly subjoined :

1. Hydraulic limestone from Reynoldss quarry, Shepherdstown, called grey cement This specimen is of a light grey colour, rather slaty fracture, moderately fine texture, and dull lustre. In the 100 grains it yielded

Carbonate of lime, 23.90 grs.

Carbonate of magnesia, 24.86

Silica, 42.90

Ox. iron and alumina, 2.10

Water and loss, 6.74

The very large proportion of silica present in this specimen, is the most remarkable feature in the above results, and illustrates what was formerly stated in regard to the highly siliceous nature, in general, of the hydraulic limestones of our state. The following specimen from the same vicinity, presents a far less proportion of this ingredient :

2. Hydraulic limestone, Beynoldss quarry, very fine texture, and nearly white colour.

Carbonate of lime, 67.50 grs.

Carbonate of magnesia, 8.86

SUica, 12.60

Ox. iron and alumina, 7.00

Water and loss, 4.64

8. Limestone — near Charlestown, on the road to Locke's tav- ern— coarse grain, very hard, of a light grey colour, apparently hjdranlio. This is one of the nnmerous localities situated on a belt of this rock, running east of Charlestown.

Carbonate of lime, 88.66

Carbonate of magnesia, 9.50

Silica, 42.60

Ox. iron, 2.00

Alumina, 1.60

Water and loss, 5.84

4. Limestone — fonr miles from Harper's Ferry, on the road to Martinsburg — coarse grain, light grey colon r, tinired with red. This specimen presents the carbonate of lime with but little admixture, and forms an admirably pure lime.

Carbonate of lime, 95.86

Carbonate of magnesia, 1.46

Silica, 1.83

Ox. iron, alumina, water and loss, 0,85

6. Limestone — from half mile west of New Market-lose and fine grained, fracture semi-conohoidal, dark dun colour, makes ex- cellent lime.

Carbonate of lime, , , . . 86.16

Silica, 4.60

Ox. iron and olumina, 0.84

Water and loss, 6.50

This is destitute of all traces of magnesia.

6. Limestone — from near Luray-rathcr fine texture, and dingy blue colour, proposed to be used as a flux for iron.

Carbonate of lime, 78.00

Carbonate of magnesia, 11.87

SUica, 6.50

Ox. iron and alumina, 0.77

Water and loss, 4.86

7. Limestone — two miles from Cliristiansburg, towards Blacks- burg, Montgomery county — rather coarse grain, irregular fracture, tendency to lamination, light greyish blue.

Carbonate of lime, 62.60

Carbonate of magnesia, 84.84

Silica, 6.84

Ox. iron and alumina, 0.84

Water and loss, 8.48

It should be remarked in relation to these results, that while in the 4th and 6th specimens we are presented with examples of lime- stone of a Yery pare character, and especially suited to agricultural nses in the others we have additional instances of the highly mag- nean and hydraulic varieties, to which reference was made in the former report, and which are here introduced with the view of con- firming the statements then given in regard to the usual aspect of limestones of this description. Respecting the dark bine or nearly black variety of which the composition was at that time particularly adverted to as eminently favourable to the production of a good aioaltaral lime, it is deemed unnecessary to add new chemical illustrations at this time. On this head I would merely remark, that the results of our analyses have been found very uniform in regard to this variety, always indicating great richness in carbonate of lime.

Adjacent to the Blue Ridge, more especially in the south-west counties of the valley, the limestone presents the jointed structure in a very remarkable degree. In Botetourt, Montgomery, Floyd, Wythe, &c. the innumerable subdivisions of the rock, marked by a net-work of veins of calcareous spar, the harsh and glistening ap- pearance of its surface when fractured, and the nearly vertical di- rection of its dtp, would seem to indicate the modifying influences to which, from its proximity to the Blue Ridge, in the great expan- sion of that mountain to the south and west, it was here peculiarly exposed. In this region too, more than in any other portion of the valley, the general tendency of the limestone to a south-eastern dip is to be remarked — in fact it rarely shows itself in any other atti- tude, and then only for a small distance. The thin layers of a more or less calcareous, dark blue or brown slate, often interposed be- tween the beds of limestone in the northern and middle counties, become more frequent and have iicreater magnitude in the south- west There, as may be well seen in ports of Floyd and Montgom- ery, these interpolated slates of a brown, red, greenish-yellow, or blue colour, occupy a large surface, forming numerous steep ridges with intervening valleys or chasms in the vicinity of the Pilot mountain, and occurring also, though less abundantly, towards the north-west margin of the valley.

This member of our series, thus extensively exposed in the great valley of the state, is also occasionally brought to light at points more or less remotely to the west. Thus the beautiful valley of Grab-bottom in Pendleton, and the Warm spring valley in Bath, owe their fertility and their gracefully undulating surface to the presence of this rock. In both these instances, as might be expected, an anticlinal arrangement of the strata, giving rise to a narrow val- ley of elevation, has caused the exposure of the limestone, while the slate and sandstone constitute the third and fourth, or two succeed- ing members of the series, dipping away from the valley on both sides, or the hills or mountains by which it is enclosed.

Organic remains, though not in general abundant in the valley limestone, may be discovered sparsely distributed in many of the beds of which it is composed, and are found in particular layers or

bands in the greatest profusion. It wonld appear that they become more nomeroas as we approach the upper limit of the limestone, where it adjoins the third or next superior member of onr series. In these positions the rook is frequentlj crowded with impressioiis and remams of Encrinites, Spirif ers, Productas, Terebratulas, Ortho- ceratites, dec. In some of the slaty bands, and in the cherty beds so largely interstratified with the limestone of the valley, GoniatitesL Ammonites, and other remains, are by no means unfinequent ana when found are generally in a beautiful state of preservation.

The travertine, or deposite marls, of which mention has been made on former occasions, though not peculiar to the limestone of which we are now treating, is so much more abundant in the great valley of the state, as to merit some notice in this place. From the extent of its exposures in many places, from its great richness in carbonate of lime, and from the facility with which without any previous preparation, it can be applied to the soil, it certainly pre- sents strong claims to the attention of the agriculturist; but, as yet, examples of its application are exceedingly rare, and never of satis- factory extent. With the view of inviting an earnest attention to this resource, by showing in how great a degree it abounds in cal- careous matter, I subioin the following chemical results. From these it will be seen, that if any good is to be anticipated from employment of calcareous manures in this region — and of such a result experience leaves no doubt — great benefits may be predicted from tlie employment of these marls.

1. Marl from Tumbling run, 4 miles from Strasbnrg,

Carbonate of lime, 84.5 grs. in the 100.

2. " from Hites mill, 8 miles north of Strasbarg,

Carbonate of lime, 87.5

8. " from Flowing Spring run mill, 2J miles from Charles- town, Carbonate of lime, 85.2

4. " from Brook creek, between Strasburg and Woodstock,

Carbonate of lime, 85.2

5. from the Opequon, between Winchester and Strasburg,

Carbonate of lime, 89.7

6. " from 6 miles north of Woodstock,

Carbonate of lime, 76.3

7. same locality,

Carbonate of lime, 91 .0

8. " from meg or Stuart's, near Waynesborough,

Carbonate of lime, 81.8

9. " from White Plains, near Newmarket, substratum in

. field, Carbonate of lime, 85.22

10. " same locality,

Carbonate of lime, 79.54

11. " same locality,

Carbonate of lime, 76.13

Besides these deposits of travertine marl, found in the valleys and along the rivulets, in almost every part of the vidley, there oo-

leveral localities io Floyd coanty, a rocky travertine of great efls and parity, and of a crystalline texture, adapting it to or ornrinental uses. Unlike the former variety, this occurs on the sides of the limestone hills, forming a mantle over preoaa rock, and evidently deposited from springs or from iral inundation of water issuing from the calcareous strata, tally fissured, and bringing with it large quantities of the le of lime in solution. In the same region, and associated valley limestone, occurs that interesting and valuable sill- ipoait, the Montgomery Bnhr. Varying from a greyish and i white to a deep orange brown, and presenting a cellular and great hardness and sharpness of grit, this unique mate- esaes qualities which admirably adapt it to the formation of les; and is accordingly, though to a much less extent than I wished, used for this purpose.

.in this member of the series that the only available deposit ore in the state occurs ; a description of the several varieties ik, M found in Wythe, was given in the report of last year, ither, and by far the most important, of the minerals it con- the iron ore, of which several of the most successful fur-

naces io the state have availed themselves, and of which, particularly as it occurs in the south-western counties, some description has al- ready been given. This mineral presents the various forms of com- pact, earthy, cellular and pipe iron ore, and in general yields a metal of admirable quality.

(No. 3.) — This member of the series consists of slates and slaty sandstones, of various shades of bluish black, lead colour and yel- lowish brown, the dark varieties in general predominating. Their structore is laminated and fissile, not unfrequently evincing the presence of a small quantity of mica. When weathered they in most cases assume a yellowish or dingy brown appearance. Usnally, Uiis slate is devoid of carbonate of lime, though bands are occasion- ally met with, containing organic impressions, and of a composition more or less calcareous. Iron pyrites is of very common occur- rence, giving origin to the sulphureous impregnation of numerous medicinal springs, taking their rise in these rocks, some of which, as the Shannondale and Winchester springs, have attained extensive reputation.

Resting inunediately upon the upper boundary of the valley limestone, (No. 2,) this rock or group of strata is exhibited on a very extensive scale along the base and flanks of the Peaked moun- tain, and the Massanntten, and other parallel ranges, in Rocking- ham, Shenandoah, Page, dec. counties. From the synclinal struct- ure of most of these ridges, the slate is exposed on both sides of the mountain, dipping inwards, that is, to the north-west on the eastern side, and to the south-east on the western side. The :trik- ing symmetry of contour exhibited by the Peaked mountain, when viewed endwise from a point south of the termination of the range, illustrates the basin-shaped arrangement of the strata of slate rest-

ing in a trough of the sabjacent limestone, and surmoanted by the sandstone which forms No. 4 of oar series. There are few, perhaps no other exposures in the state in which the stractnre and relations of these slates can be so satisfactorily observed, as in the group of raonntains here referred to ; and in no part of this interesting region can such observations be made with more readiness, and more in- structive results, than in the line from MGaheysville, across the Peaked mountain, towards Eeezle Town. Leaving the former place, which is situated in the valley limestone, we are accompanied for some distance by that rock, presenting a dtp towards the mountain, that is, to the west and north. Quitting the limestone we enter upon the slate resting upon it and exhibiting the same dip. This rock attends us as we ascend the eastern side of the ridge, always presenting the western dip, and exhibiting towards its upper bound- ary bands of a more calcareous nature, and thin layers of a dark brown slaty sandstone, both of which abound in impressions of en- crini and other organic remains. This brings us to the massive white sandstone, hereafter to be described, which rests conformably on the slate, and forming a deep trough or narrow valley on the top of the range, is seen dipping towards the east and south, high up along the western side. Descending below this sandstone we reach the slate again, now dipping to the east and presenting the same characters as on the eastern slope. This continues to near the base, when we meet with the limestone dipping beneath the slate, or to the east, and thus completing the trough-shaped, or synclinal arrangement of the strata of the mountain. Beyond the northern termination of this group of mountains the slate forms a wide belt, passing through Frederick county and on to the Potomac, and im- parting marked peculiarities to the topography and agricultural features of the region. A similar prolongation of this rock may be traced south of the Peak, near Eeezle Town, extending with a vari- able breadth through Augusta county, where it is finely exposed on Christianas creek, near Staunton, and even passing into Rockbridge. Besides occurring in various other parts of the valley, in greater or less extent, it is also exhibited, as will readily be inferred, along the margins of those anticlinal valleys, such as Crab-bottom and the Warm spring, in which No. 2 occurs, lying upon that rock, and pre- senting the same general characters as above described.

In an economical point of yiew, this rock is chiefly interesting, from being the repository of beds of iron ore of great extent and value, and of large deposits of the oxide of manganese. In regard to the former, incalculably the more important of the two, the ex- traordinary productiveness of this rock has already been illustrated in sketching some of the results of our researches in the Big and Little Fort valleys of the Massanutten. But I may be allowed again to call attention to the rich abundance and excellent quality of the iron ores appertaining to this member of our series, as forming a part of the structure of those mountains, as well as to the ample de- posits exhibited in numerous other localities in connexion with the same rock. Though not unfrequently impregnated with manganese,

these ores are, for the most part well adapted to the furnace, and yield a metal of excellent quality. Their position is generally near, or at the upper limits of the slate, or between it and the sandstone, and they aeem to have been derived from the ferruginous ingredi- ents of both these rocks, through the influence of slow chemical changes and inflltration.

From the resemblance this slate occasionally presents, both in colour and texture, to the shale of the coal measures, expensive ex- plorations have been made with the view of reaching the coal it has been supposed to contain. But, as I have already stated, there is no warrant for such an opinion, either in the geological situation of the rock, or in the results of observation in Pennsylvania, as well as this state.

(No. 4.) — Resting upon the slates above described, there occurs a group of sandstones of which incidental mention has already been made in treating of those rocks, as exhibited in the Massanutten ranges. This member of our series may be described as conMisting of alternations, generally two in number, of red or brown, and com- pact white sandstone, the former frequently graduating into an ochreons shale. The latter rests upon the shide or red sandstone in both instances, and from its massiveness, durability, and the white- ness of its weathered surfaces, forms a very conspicuous feature in the geological scenery of many of our mountain?. Near the upper limits of this group, as well as in connexion with the shaly bands beneath, organic impressions are often abundantly discovered. The thin slabs of buff and olive sandstone lying near the top, are partic- ularly rich in these remains, among which may be noted as pecul- iarly abundant, a small globose terebratula, and at least two well characterised species of fucoides. Cylindrical markings, similar to those of No. 1, are often exhibited in great numbers in the more compact and fine-grained white or pinkish white strata of this group. An iron ore is frequently associated with the more slaty strata, and is of almost invariable occurrence in connexion with the ponderous brown sandstone which forms the boundary between this and the next superior member of the series.

In the Peaked, Massanutten, and other adjacent ridges, the shaly bands are scarcely to be discerned, while the white sandstone is <leveloped in great extent, forming all the upper portion of the mountain, and presenting long lines of cliffs on either side. Here much of the rock is a coarse and very hard conglomerate, the fra(; ments often angular, and generally but imperfectly water worn, thus adapting it to be used for millstones, and giving it a texture and as- pect strikingly distinguishing it from the coarse sandstones and con- glomerates occurring higher up in the series. In the region lying to the west or north-west of the great valley, where the chief expos- ures of this group of rocks occur, they present all the characters above described. In many of the more massive mountains in this part of the state, these strata are found in the interior of the range, forming one or more enormous and sometimes unbroken arches, -sue-

tainiDg the rocks placed higher in the series, and exhibiting in the natural sections bj which the interior structure is exposed, some of the most wildly picturesque scenery in the state. The Great North mountain lying to the west of Rockingham and Shenandoah coun- ties, is composed of this sandstone, even to its very summit ; and on its top, and along its rugged and almost inaccessible sides, bears witness to the violence of the dislocating forces which have bent these massive strata into arches, broken them at sharp angles, and tilted them on end or folded them together.

Immediately exterior to the slate which rests antidinallj upon the limestone of the Warm spring, Crab-bottom, and other valleys of elevation, these strata reposing upon the former, lie along the outer sides of the enclosing mountains, spreading a mantle of white and almost her bless rocks far down the declivity of the ridge, and forming a range of precipices, like a line of lofty battlements along the mountain top. Such are the curious and striking features pre- sented in the Warm Spring mountain, and the still more remarkable ridge, called the DeviPs Backbone, as well as in numerous other situations in which our researches have been pursued.

In numerous instances, of which the Enobly and NortJi fork ranges may be taken as examples, the rocks of No. 4, rising in the middle of the mountain, in tiie form of a stupendous arch, divide the mountain into three parallel ridges ; this rock composing the central one, and the rocks of 6, 6, &c. forming those on either side, thus presenting a beautiful symmetry of arrangement in the midst of apparent confusion, and Indicating the extent to which denuding forces must have operated to remove the vast incumbent mass, which was borne up by the rising strata, when the great central arch was originally elevated.

Another very curious and striking exhibition of the rocks of No. 4, is displayed in the loug line of hills, which is washed at its western base, by the waters of tlie North fork of South branch of Potomac in Pendleton. Here the strata are literally on end, and the rocks of No. 4, instead of forming an arch, are folded together by a sudden bending at the top, as if the two sides of the arch, by the violence of lateral compression had been brought in contact, while the rocks of 6, 6, 7, &c. are symmetrically disposed in almost verti- cal planes on both sides of the crushed axis. The massive strata of No. 4, resisting the action of tlie weather, or of denuding forces, are seen towering above the adjacent more destructible rocks, and at each of the numerous openings in the range, these white sheets and grotesque pinnacles of rock, rising on either side, add a pecul- iar wildness to the vista-view of dark-wooded slopes of the Great North Fork mountain, of which we are thus permitted to obtain a glinipse.

The frequent connexion of this member of the series, with scenes of scientific or picturesque interest, might be illustrated by numerous other examples, but I will content myself with remark- ing, that in the Peters, Wolf creek, and other mountains, in the south-west, this rock plays a conspicuous part ; that in the Jack

motinUin, it presents two arches, one of them of enormous bread th| giYmg rise at their jonction to the celebrated Barn rock ; and in Brown's mountain, in Pocahontas county, it exhibits the curious spectacle of twelve arches, many of them entire and of the most beautiful contour, occupying a distance of more than two miles along the bank of Nap's creek, where it traverses the mountain.

(No. 5.) — Next above the massive sandstones and shales just de- scribed, is a group of soft slates and shaly sandstones, with occa- sional calcareous bands, of various tints, of brown, yellow, green and lead colour, frequently presenting a mottled aspect, especially from the occurrence of blotches of green and yellow, in the more massive dark brown strata. This member of the series, is of incon- siderable thickness in the middle district. It expands as it proceeds north, and in Hardy and Hampshire counties, where it is well de- veloped, exerts a marked influence upon the topography of the mountains, from the readiness with which it is decomposed and worn down by the action of the atmosphere or other causes, it usu- ally imparts to the tops or sides of the mountains in which it is ex- posed, an undulating form, and occasions that peculiarity of topog- raphy already adverted to, in describing the triple structure of parts of the Knobly mountain.

In the south-western counties this member of the series becomes far more largely developed, embracing in addition to the shaly strata, numerous beds of sandstone, and containing that peculiar species of slate which forms the repository of the vast beds of gypsum in the valley of the Holston. In fact, in that region the developement of these parti-coloured and calcareous shales is even greater than in the heart of Pennsylvania, and seems to bear a marked resemblance to the expanded form in which they occur in the gypsum and salt region of New York. The transition of these strato from the com- paratively insignificant dimensions which they present in the middle district, to their expanded form in the south-west, has yet been but imperfectly traced, and will afford an interesting subject for future Investigation, especially as connected with the precise determination of the boundaries of the gypseous and salif erous rocks.

As already indicated, these shales are the repository of the very valuable form of iron ore previously mentioned. From its occur- rence in thin beds, interstratified with the calcareous shales, from its being usually filled with impressions or hollow casts of shells and other organic remains, and from its resemblance to a dark brown fossil iferous slate or saZkdstone, it admits of being very readily iden- tified, even by those but little accustomed to the examination of minerals. So uniform appears to be the association of this ore with the present member of our series, that besides being exposed in most of the ridges of Hampshire, Hardy, Bath, <&c., as formerly stated, it is exhibited at many points in the valleys of the Massanutten, where these shales are brought to light. The observations already made upon the economical importance of this ore, will, it is hopeo, invite attention to it, and the above descriptive remarks, in regard

to its form and geologica] relations, may prove nsef ol in aiding its developement.

(No. 6.) — Overlying the strata above described, and often blend- ing with them by repeated alternations of shale and limestone in thin beds, we meet with a limestone of more massive 'Ysharacter, though still at intervals presenting the shaly hue and structare. This member of the series is remarkable for its richness in Encri- nites, shells and other organic remains. In fact, many of the strata, especially towards its apper limits, have the appearance of being en* tirely formed pf these exuvi®. In the northern and middle districts where its characters are most uniform, and have been most ezten- sively observed, it is found to assnme a more arenaceous structure as it approaches the overlying sandstone No. 7, and when seen in mass exhibits a peculiar rough and mealy surface, which makes it easy to be recognised. "When bruised or rubbed, especially if the experiment be made with a fragment from the upper beds, it ex- hales a strong bituminous odour. In many of the exposures of this rock, the beds adjacent to the sandstone No. 7, are interspersed with small calcareous and siliceous pebbles. The lower strata of No. 7, are separated from each other by thin layers of a highly bitu- minous conglomerate of the same description, of which in some places I have counted twenty in the space of thirty feet. In the south-west, the developement of this limestone appears to be co-ex- tensive with that of the subjacent shales. Extending from the west- ern base of Walker's mountain to the commencement of the gypse- ous shales, in the valley of the north fork of Holston, it imparts fer- tility, together with a singularly picturesque character, to that inter- esting region. Though less abundant in organic remains here than farther north, it still contains them in some of its strata in great numbers. The cherty beds which occur as we approach the sand- stone, are sometimes of very considerable thickness, in the northern and middle districts. In the south-west, a chert or buhr rock, of superior quality, is found at its lower limits, and adjacent to the shales. In this district a more shaly structure of the limestone pre- sents itself in approaching the overlying sandstone, and near the foot of the western slope of Walker's mountain, a reddish shale oc- curs in heavy beds. In an economical point of view, this member of the series has strong claims to our interest, from the fact that it is the only limestone exposed over wide tracts of our mountainous regions, and is often extensively spread out along the tops or on the flanks of the broader ridges. In Hampshire, Hardy, Pendleton, Bath, Alleghany, &c. counties, numerous available quarries are to be found, furnishing a material well adapted to the manufacture of lime for agricultural or building purposes, and as will hereafter be pointed out, the slaty soils of No. 8, occurring in the contiguous tills and valleys, are of a nature to receive peculiar benefits from the application of this species of manure. As presenting extensive and interesting exposures of this limestone, I may here refer to the Knobly, Patterson's creek, Capon, North fork. Prop's gap, BuD-

putare and Back creek moaDtains, and to the valleys of North fork of Sooth branch, Jackson's river, Cow pasture, Walker's creek, and North fork of Holston ; in aU of which regions, it famishes a resource of no inconsiderable value.

(No. 7.) — The sandstones composing this member of the series, are in general, characterised by an open and rather coarse texture, and an extraordinary abundance of organic impressions. In colour they vary from a yellowish white to a dark greenish grey. They are usually presented, especially the lighter coloured variety, in mas- sive beds of several feet in thickness, and from their frequent occur- rence along the flanks and declivities of the ridges, dipping at a steep angle, and bare of vegetation, they form a curious feature in many of the wild scenes among our mountains. Frequently exposed in broad sheets of remarkable whiteness, high up upon the sides of the hills, they arrest the attention of the traveller, even when at a distance, and still more interest his curiosity, when upon a nearer inspection he finds them teeming with the relics of a former anima ted world, and exhibiting over wide surfaces of exposure, a display of these remains at once prodigal and diversified, and full of useful illustration to the geologist.

The arched structure remarked upon in describing the sandstone No. 4, is also conspicuously and beautifully displayed by this mem- ber of the series. Frequent exhibitions of continuous and succes- sive arches of admirable symmetry and imposing grandeur, are met with in the nortliern and middle districts, where the deep gaps in many of the ridges admit us to a view of these sandstones, and occa- sionally the subjacent limestone. A noble specimen of scenery of this kind is to be found at what are called the Hanging rocks, in the neighbourhood of Romney, where the Sooth branch mountain gives passage to the South branch of the Potomac, flowing towards the east. Here the river flows along the base of a long line of precipi- tous rocks, arranged in the form of three stupendous arches, of which the most eastern is 250, the second 650, and the third 220 yards in span. Nearly all the mountains of Hampshire, Hardy, Pendleton, Bath, Pocahontas and Alleghany counties, previously re- ferred to, exhibit extensive and instructive exposures of this rock — which from its whiteness, frequently bare surface, profusion of or- ganic impressions, and dispos!tion to disintegrate into a coarse white sand, is one of the most strongly and uniformly characterized of the members of our series.

An iron ore has been found in various places in connexion with these strata, but of its extent and probable value, I am not yet. pre- pared to speak.

(No. 8.) — Resting in contact with the sandstones above de- scribed, and nsually forming the lower hilly slope of the mountains in which they occur in arched or anticlinal form, we meet with a dark colonred and very fissile slate, which constitutes the lowest bed of the group of slaty rocks forming the eighth member of the

serios. These Btrata which ocoapy a large extent of enrface in onr mountain region, are not less conspioaonsly characterized hj the topographical features to which they give rise, than by their marked peculiarities of hue and structure. Sharp, irregular hills, deeply furrowed on their sides, and succeeding each other with hut little order or arrangement, mark the topography of the regions in which these rocks occur. A. further and equally conspicuous characteris- tic of the rocks in question, consists in their frequent and remark- able contortions, a phenomenon well calculated to awaken curiosity and surprise wherever they are extensively exposed. Very obvious differences of structure and external characters are presented in dif- ferent portions of this series of slates, and have suggested the pro- priety of a triple subdivision of the strata. The lowest of these rocks, or that which rests upon the sandstone No. 7, distinguished by its bluish blaok colour, and by its scaly and fissile texture, caus- ing it to fall into thin wafer-like fragments, or to crumble in slender fibre-like pieces, resembling portions of decaying wood, I have designated as the black fissile slate of No. 8. The second variety, presenting various dark shades of green, but more especially re- markable for a deep olive tinge which is most pleasingly displayed in the weathered and fragmentary condition of the rock as it occurs along some of the highways of the state, I have denominated the olive slate of No. 8. The third, which is much less uniform in ap- pearance, or homogeneous in composition, than either of the pre- ceding, embraces many beds of more massive structure, exhibiting, especially in its lower and middle portions, a yellowish green and a deep brown colouring, and always distinguished by tibie rusty or ochreous staining of its weathered surfaces. Becoming more siU- oeous as we approach its upper boundary, it terminates in thick beds of sandstone of a dirty grey colour, frequently mottled with purple or greenish spots. This I have named the ochreous portion of No. 8.

The presence of iron pyrites in nodules, generally of a spheroidal form, or in a disseminated state, especially in the lowest of the sub- divisions above described, favours the disintegration of the rock, gives rise to the incrustations of alum, copperas and gypsum, with which its exposed surface is usually overspread, and imparts to the springs arising in it, ihut sulphureous and chalybeate impregnation for which they are generally remarked. Though not in general rich in organic remains, these slates contain many bands or thin beds abounding in them in a very high degree. £ncrinites, Spiriiers, Productas, Terebratulas, are crowded together in the closest con- tact, and furnish interesting specimens for geological comparison and description. These organic layers are, or evidently have been, more or less calcareous. A stratum of limestone of pretty good quality, and two or three feet in thickness, is frequently found in- terpolated among the upper beds of these slates, and is remarkable' for tiie number and beauty of the impressions it contains.

The exposures of this member of the series are so numeroner and extensive, that it is almost unnecessary to refer to particular dis- tricts for exemplification. I may, however, be allowed to remark

upon some of its more important localities, as iUastrating its geo- logical position and characters. The Cowpastore hills, of which an interestinff section may be observed along tbe tumpilce road leading through Jennings's gap, together with much of the comparatively level region, extending to near the base of the Warm Spring moan- tain, present admirable exposures of all the subdivisions of these slates, and strikingly exemplify their tendency to contorted arrange- ment. Similar and equally instructive exposures are exhibited throughout a large part of the route from the Warm spring valley, by Cedar creek and Oallahan's, to the White Sulphur springs. Oc- casionally tbe subjacent sandstone, No. 7, rises into view, and some- times even the limestone, Ko. 6, still lower in the series, is brought up as at Callahan's rock ; but for the most part, tbe road winds among the steep and broken hills of No. 8, occasionally exposing portions of the next superior member of the series. The ridges usu- ally designated as the Alleghany in this portion of the state, form- ing the eastern boundary of Pocahontas county, and lying west and north of the Warm and Sweet spring valleys, are for the most part made up of the rocks of No. 8, capped in some places by the lower rocks of No. 9. ' In the structure of the Branch, or Great Shenan- doah mountain, the relations of these slates are well exposed. The basin-shaped or synclinal arrangement of the rocks of this lofty and rugged range, exhibits these strata dipping under the mountain, on both its eastern and western flanks, ana forming the wildly broken, and strongly shaded hills, which are crowded along its sides.

The hills whose diversified and picturesque outlines, impart such interest to the scenery around the White Sulphur springs, are chiefly composed of these slates, the lowermost division of which may be seen in various points, resting on the flanks of the sandstone bill (No. 7,) from the bosom of which the waters of the spring make their escape. These rocks accompany us for some distance towards the Greenbrier river, and then give place, successively, to the higher members of the series, until we find ourselves surrounded by the strata of No. 11, in the vicinity of that stream.

In Hampshire, Hardy and Pendleton counties, the strata of No. 8, are extensively exposed along the sides of the anticlinal ridges, such M the Capon, Sandy, Pattersons creek. South branch, Enobly, North fork and BuUpasture mountains, and occupy most of the in- tervening valleys. In Bath, Alleghany, parts of Greenbrier and Monroe, Rockbridge and Botetourt, as well as some of the more southern counties, their topographical relations are much the same ; though in proceeding far south, important modifications arise, both in the material and structure of these slates.

Iron ore, and manganese are met with in these rocks. Thin beds of bituminous shale, with small laminss of impure coal, have been discovered at several points in the lowermost strata, but thus tar the results of our observations are such as to discountenance any probability of finding this mineral in available qnantities in the rocks of No. 8.

It may not be unimportant to remark, that the soils produced by

these Blates are of very various degrees of productiveoess; some be- ing distingnished for their fertilitj, whilst others yield the fanner oomparatively stinted returns. But in all cases, they appear to poe- sess a peculiar susceptibility of improvement, from the application of lime, or calcareous matter in other forms. This interesting fact, evinced by observations in several localities, is stnkingly in har- mony with the results of experiments in ocher quarters of the state, where soils or clay, imbued with the sulphates found in these slates (alum and copperas), have been rendered quite productive by the addition of marl. As gypsum is not unfrequently found in the efflorescence on these slaty rocks, and as moreover, I have detected it in the slatj fragments mixed with the soil in several places, we naturally look to it as one of the causes of the superior fertility' which some of these soils exhibit, while we would explain the ame- lioration of others when acted upon by lime, by the readiness with which, under these circumstances, gypsum would be formed. It is interesting further to remark, that tne means of improving these slaty soils is generally within easy reach — as from the usually steep inclination of the strata, we have to proceed but a small distance be- fore we reach the outcrop of the limestone beds of No. 6. Indeed, in a great majority of cases, tbese strata are exposed in the gaps, and along the flanks of the hills enclosing the region in which the soils demanding the application of lime occur.

Sulphuretted waters are of very common occurrence in No. 8. In general, the impregnation, gaseous as well as solid, is not great ; but in many instances, it is fuUy competent to the production of striking remedial effects, and justifies the repute in which several of these waters are held.

(No. 9.) — This member of the series exhibits less constancy of character than the preceding. In the northern district, it consists of shales and slaty sandstones, generally of an argillaceous composi- tion, and presenting an alternation of beds of brown, red, green, yellow and dark grey colouring. Proceeding south, the argillaceous composition and the variegated hues of these strata become less striking, until in the middle district a dark brown micaceous, and somewhat argillaceous sandstone, and slate, is found to occupy the principal share of this division of the series.

In Hampshire, where the rocks of No. 9, are beautiful! j exhi- hited in their variegated character, we would refer for localities to Townhill, and Big and Little Timber ridges. The synclinal struc- ture of the Shenandoah, or Branch mountain, of which mention has already been made, beautifully exposes these variegated shales along the higher portions of both the eastern and western slopes, first ap- pearing immediately above the greyish sandstone of No. 8, and ter- minating in the most elevated parts of the range at a small distance helow the summit, which here is formed of the strata of the next superior member of the series. Further south, along the same ridge, as at Dry river gap, and towards Shawns ridge, the monoto- nous brown or dark reddish slate becomes predominant ; and under

the same modifications, tlicse shales appear on the eastern declivity of the front ridge of the Alleghany near its hase. In the neighhour- hood of the White Solphnr, as before stated, between Huntersville and the Greenbrier river, in Pocahontas county, and in numerous other districts, these reddish slates of No. 9, are extensively exposed, but perhaps in no district do they present more satisfactory or striking developements, than in the wild gorges which lead from the lime- stone region of Rockingham, through a succession of precipitous and lofty hills, to the eastern base of the Shenandoah mountain. The strata dipping very gently to the east, in consequence of an anticlinal turn near the eastern foot of the ridge, we have here spread oyer an extensive surface, the rocks which with a steeper dip are compressed within a part or the altitude of the mountain and the violence of denuding action have deeply channelled these nearly horizontal rocks, we are admitted to a view of a series of lofty pre- cipices composed of the massive beds of No. 9, revealing most ad- vantageously the composition and structure of the strata.

(No. 10.) — This consists of rocks of very heterogeneous charac- . ter, though arranged in general with remarkable uniformity. A red sandstone containing white siliceous pebbles, usually about a half inch in diameter — a grey, rather open grained sandstone, and a beau- tiful white conglomerate — a coarse conglomerate, consisting of very large pebbles, embedded in a light olive or dingy green pasteyel- lowish, olive and dull red micaceous soft sandstones — having some- thing of a shaly structure, constitute the principal rocks forming this curious group. Beautiful ripple markings are often met with on the surfaces of the large slabs of the finer of these sandstones. Many of the strata of this, as well as the nreceding member of the series, are remarkable for the facility with which they may be di- vided into thin slabs of uniform thickness, and great extent, and in virtue of this property, as well as the durable character of the rock, present an admirable material for building. The finer and harder variety, of a grey or light yellowish green colour, is often used for grindstones, for which it would appear to be admirably suited. When thus cleft, the surfaces of the slabs occasionally reveal superb collections of organic markings, among which f ucoides and calamites deserve to be particularly mentioned. Laminro of coal less than a quarter of an inch in thickness, have been remarked at several points in the more shaly strata of this group, but there is no reason to look for an important vein of this mineral amons: them. These rocks may be well seen near the bridge over Howard's creek, on the road fVom the White Sulphur to the Greenbrier river, and again a little east of that river, on the road fh>m Huntersville to the base of the Greenbrier mountain. In the latter locality the coarse con- glomerates are very extensively exhibited.

(No. 11.) — The group of limestones, shales and sandstones, cora- poshig this member of our series, possesses neculiar interest, as well on aocomit of its geological and economical importance, as the ex-

tensive region over which it is spread, and to which it imparts fer- tility. As formerly remarked, near the northern houndary of the state, the calcareous rocks, forming a portion of the group, are hat slightly developed, and at some distance further north, in Fennsyi- vania, limestone, in the form of distinct heds, is entirely absent, al- though calcareous matter is found intermixed with the other mate- rials of the shales. As we advance siuth the limestone assumes more and more importance, until upon reaching the borders of Greenbrier river in Pocahontas county, it ridly spreads out on either hand, and widely mantles the counties of Greenbrier and Monroe, extending also over portions of Fayette, Giles, and the counties still more south. This great and sudden augmentation of topographical extent, is not, however, to be regarded as marking a corresponding degree of expansion in the thiclmess of this member of the group. On the summit of the Alleghany, beyond the head of Seneca credc, as we enter Randolph county from the east, this rock, accompanied with variegated shales, is developed over a consider- able surface, but its comparatively steep dip here, and for some dis- tance further south, contracts ihQ area of its exposure, while in Pocahontas, and still further to the south, it assumes a nearly hori- zontal attitude, gently undulating, but for the most part dipping to the west. Much of this limestone is distinguished by its argilla- ceous composition, presenting, when weathered, an ochreous yeUow surface, arisipg from the removal of the carbonate of lime, which leaves the earthy matters, retaining the original form of the inass, but peculiarly liable to disintegrate by exposure, and giving rise to a light coloured and tenacious clay. Tbe purer varieties, A which also there are abundant exposures, are usually of a deep blue colour, and are found to produce a very strong lime. They are often highly bituminous, and in many cases contain a marked proportion of car- bonate of magnesia. Numerous specimens are now in progress of analysis, of which, therefore, no special details can be presented at this time. It will suffice to remark, that they present similar vari- ety, as to composition, and applicability to useftd purposes, as the limestones of No. 2. Many of these strata are exceedingly rich in organic remains, of which a considerable number do not make their appearance in the lower members of our series. The variety, pecul- iar characters, and admirable preservation of these relics, will claim ' for them an attentive examination.

The shales already alluded to, as associated with the limestone of No. 11, are remarkable for the richness of their purple, green and yellow tints, and in this particular as well as in their peculiarly crumbly texture, when exposed, bearing a striking resemblance to the shales of No. 9, as exhibited in Hampshire and Hardy counties. The hues are, however, much more brilliant, and the more massive exposures in which they are seen give them a higher interest. While on the one hand graduating into strata of limestone, from the in- creasing predominance of calceons matter, they are seen on the other, becoming more and more arenaceous, until at length their usual character is merged in that of a yellowish or dark brown

sandstone, generally of slaty structure, bnt presenting in some of its beds the hard and massive character of the sandstones lower down in the series. Of the foil extent of these alternations in the mem- bers of the group forming No. 11, I am not yet prepared to speak with certainty, as the western confines of these rooks have as yet been iuadequately explored.

It is, however, important to remark, that the seams of bitumi- nous coal discovered in the vicinity of Lewisburg, as well as west of the Greenbrier river higher up, occurring in the sandstones of this group, and therefore below the true coal measures which appertain to the next member of our series, cannot be regarded as likely to prove of much value, the sandstones and shales in which they are lound being themselves but a small subordinate formation, and the coal embedded among them in inconsiderable quantity.

As among the viduable materials associated with the limestones and shales, just spoken of, I may be allowed again to notice an iron ore of highly promising character, which has been discovered at several points m Greenbrier and Monroe. Should I be correct in my opinion of its good qualities, and of this chemical examination will ftiroish the means of Judging, its value will soon be doly appre- ciated, as it indicates a character greatly resembling that of the strati- fied ore of the shales of our No. 6, and I have reason to believe, may be obtained in abundant quantities.

The pleasing scenery of the region of these limestones and shales, so often adorned by a rich cultivation, strikingly exhibits the influ- ence of geological structure on the resources and the prosperity of a country, by bringing into the strongest contrast the undulating re- gion to which industry was invited, and which it is now rapidly beautifying, simply on account of the presence of calcareous rocks, and the rugged hills and mountains from which enterprise has been repelled by the presence of the barren sandstone, or the equally un- productive siliceous and ferruginous slate. The calcareous nature of the variegated shales adapts them to the production of a genial soil, and thus we find a rich vegetation following the exposures of these rocks high up along the slopes of many of the hills, until sud- denly arrested by the barrier of sterile rocks above.

(No. 12.)— This member of our series, not falling within the re- on of our explorations during the past season, cannot be described at this tiraow Lying immediately beneath and incorporated with the widely extending coal measures of the west, its great importance will claim future detailed and extensive observations.

The above description of the several members or subdivisions of our series of rocks, in the order of their superposition, will, it is hoped, be found to contribute to useful as well as interesting results. While it will serve to elucidate many portions of the preceding re- ports, and form the key to much of the present, and those which are to follow, I would gladly believe that it will awaken a spirit of observation in regions where such a spirit may be beneficially exer-

cised, giving to it a direction nt once safe and condnciye to snccesa. Suggesting interesting practical enqairies, and guiding the researches of those who are in parsnit of economical resolts, it will giye to the investigation of our geologj, even in its scientific generidities, that stamp of practical asefalness which even those who, unaware of the relations of scientific truth to the welfare of society, will be c<m- strained to recognize and admit.

Appendix.

From the statements which have now been presented in relation to the scene and objects, as well as a few of the results of our labours during the past season, some idea may be formed of the extent to which we were enabled to prosecute active operations in the field, aad of the success that attended our researches. In further illustra- tion of these points, and as intimately connected with the present and future usefulness, as well as with the progress of our investiga- tions, I may be permitted briefly to advert to the following addi- tional facts and considerations.

In pursuing the chemical enquiries connected with the survey, which have been for the most part conducted under my immediate superintendence at the University, the want of a laboratory more extensive and complete than that previously used, specially fitted up and provided for the work, has induced me to erect a building for the purpose at my own expense, furnished with ample means for analytical research. During a part of the autumn and up to this time, chemical enquiries have been in active profiress in this estab- lishment, and from the increased facilities thus afforded for the pros- ecution of this branch of our investigations, I indulge the hope of rendering it even more important and extensive than it has hereto- fore been. The high value of these researches, manifested by the eagerness with which the chemical details embodied in the annual reports are referred to for practical objects, is still more strikingly illustrated by the numerous enquiries addressed to me, and the nu- merous specimens transmitted for examination from various quar- ters of the state. The amount of chemical investigation thus be- stowed upon the materials of economical value, collected in our explorations or forwarded to us from localities not visited, though not mentioned in the annual reports, forms a very important item in the yearly operations of the laboratory, furnishing useful facts and vain- able practical suggestions in relation to the nature and appropriate application of our marls, limestones, iron ores and other important mineral resources, and thus silently, but largely and continually, difiTusing information of immediate practical utility to persons in every dbtrict of the state.

In the graphical department of the sarvej, considerable progress has been made in the oonstraotion of coloured sections, exhibiting the stracture of the regions in wliich oar enquiries have been pursned ; but much additionid work of this description is yet required to give the neoessary fulness to our elucidation of the mountainous districts, and to this end numerous accurate measurements, and a large amount of other labour demanding topographical skill remain to be performed.

The number and the magnitude of the errors of our state map already incidently mentioned, have been found to be so important as to render it eitremely difficult and almost useless to introduce geological delineations upon its surface until the requisite corrections have been made. This we have endeavoured to do whenever in our power, and our corrections have already been neither few nor unimportant — but in view of the magnitude and high utility of this branch of our labours in regard to the geographical as well as geo- logical uses of the map, I feel it to be my duty to add, that it would be desirable at as early a period as practicable to obtain additional force for topographical as well as geological operations. The board will better appreciate the grossness and the frequency of the blun- ders committed on the map from the following facts. On examining the county maps, in the archives of the state, from which the gen- eral map has been formed, the most extraordinary instances of inac- curacy or carelessness occur. The common boundary lines of two adjacent counties, which should be identical as to direction and length, are rarely found to correspond in the latter particular, often differing by a large amount. The adjoining parts of the same river or stream are frequently incapable of being brought into juxtaposi- tion without greatly distorting other portions of the map. In a multitude of cases the directions of streams nnd moantains, are falsely represented ; sometimes ohjects of this kind are laid down where they have no existence, and still oftener omitted where they are sufficiently important to merit notice. The distances between places even of prominent note are greatly exaggerated or reduced, and in one instance observed during the last year the error was no less than the difference between four and twelve miles. Though, pervading all parts of the map, to some extent, and not less manifest in some of the tide water counties than in the mountain districts, where the difficcdties of measurement render them far more excus- able, these errors are felt with particular inconvenience, in the geo- logical delineation of the latter portion of the state, from the number of distinct rocks or groups of strata to be represented, from their being frequently crowded together in a narrow compass, and from their peculiar exposures being for the most part intimately connected with the topography of the mountains or valleys in which they a]>- pear. In attempting to re])resent them in geological colours upon the map, in many cases it was found that a great distortion of their relative position and extent would be rendered necessary in order to maintain a proper correspondence of the geological and topographi- cal features of the district as they had been observed, so that in fact a large share of the great and permanent benefits anticipated from

an accnrate geological colonring of oar map must obvionaly be sacri- ficed, nnless efficient means be placed in oar hands for correcting the nameroas and glaring errors which so greatly impair its valne in its present form. While, therefore, oar attention will be directed to these corrections whenever within our power, I cannot but hope that in consideration of the great and varioas advantages of an im- proved state map, an adeqaate provision for this object will at some earlj day be placed at my disposal, thus enabling me to incorporate with a more faithful representation of the topography, a minute and accurate delineation of all the geological featorea of the atate.

E E P O E T

or THE FROOBE88 OF

The Geological Survey

Of

The State Op Virginia,

For The Tear 1838,

OfFIOX or TBI BOABD OF PUBUO WOBKS,

April 2, 1889.

Snt, I herewith transmit the report of the geologist of the state shewing the progress of the sarvey under his direction during the past year, which you will please lay hefore the house of delegates.

I am, very respectfully,

Your obedient servant,

David Campbell, President of the Board of Public Works,

The honourable the leaker of the House of Delegates.

Report.

Jir conformity with the law requiring an annual report of the progress of the geological Borvey to be snbniitted to the board of pabuc works, I beg leave to make the foUowing report :

During the season preceding the last, as the board is aware, con- riderable progress was made in the ezploratioq of the division of the state extending from the western flank of the Blae Ridge to the long and irregular escarpment in which the coal bearing rocks of the west are first displayed. The importance of a Aill and minute acquaint- ance witli the structure of this region in deciding various interesting questions bearing upon the extent and value of its mineral resources, as well as in facilitating the investigation of the extensive and rich territory spreading from its western boundary to the Ohio, rendered me particularly solicitous to complete its exploration as early as was compatible with a minute and thorough examination of every object of sdentific or practical interest which it embraced. With this view, I thought it expedient to amend the plan of operations previously determined upon, and in part referred to in my last yearns report, by suspending until the next season the completion of our researches in the Tertiary marl region, of which the greater part has already been explored, and devoting all our efforts to this most difficult and intricate portion of our task. As the result of this plan of opera- tions, it gives me pleasure to inform the board, that with the excep- tion of a few points of comparatively little interest remaining yet to be examined, the structure and resources of every portion of this region have now been thoroughly investigated, and that with the mass of detailed information thus procureid, I am already entering upon the task of delineating its geology upon the state map, accom- panying the representation of the strata as they occur over its sur- face, with such topographical corrections of the map itself, as numer- ous observations made with this view enable me to introduce.

The active operations of the survey were commenced early in April, at which time my assistants, professor J. B. Rogers, professor W. £. A. Aikin and Mr. 0. B. Hayden, entered upon their field duties,

snitably provided and equipped. A little later in the season two ad- ditiond assistants were engaged, Mr. I. Slade and Dr. George W. Boyd, who repaired immediately to their respective tasks.

The subdivision of the region to which our investigations were principally directed into three districts, as adopted during the pre- ceding season, and referred to in my last yearns report, was retamed with little or no modification, as best suited for the prosecution of further research ; and for a similar reason each of the assistants who had already been employed in this part of the state, was placed in the district which had been the scene of his labours during the pre- ceding year, and with the topographical and geological features of which he had become in some degree familiar. Accordingly, the northern district was assigned to Mr. Hay den, in conjunction with Mr. Slade — the middle to professor J. B. Rogers, assisted for a time by Dr. Boyd — and the southern to professor Aikin. To Dr. Boyd was afterwards allotted the duty of making a continuous examina- tion of the rocks along the western flank of the Blue Ridge, so in- teresting for the number and extent of their beds of iron ore, and of extending his researches into the southern and northern districts, as well as making numerous sections across the muuatain to its eastern base.

In addition to the researches thus prosecuted within the three subdivisions of the extensive region constituting the principal scene of our labours, some preliminary investigations were made towards the dose of the season, both in the cosJ bearing strata, extending fom the western boundary of this region to the Ohio, and in the midland counties lying east of the* Blue Ridge. Aided by the re- sults of these and previous observations, we feel ourselves prepared to enter systematically upon the exploration of both these divisions of the state early in the next season and it gives me pleasure to add, that the comparatively simple geological features they present, and the dear general views in relation to their structure and resources already acquired, will enable us to make rapid progress in the devel- opment of whatever is interesting or valuable within their limits.

In the ehemieal department of the survey the improved labora- tory arrangements referred to in the appendix to my last yearns re- port, have greatly facilitated our regular analytical operations, as well as various collateral enquiries relating to the practical value and applications of some of the useful materials collected for examination. These researches, conducted by myself when not actively employed in the field, and since the close of our explorations prosecuted under my superintendence by two of my assistants, Messrs. Hayden and 81ade, are still in progress, and wiU be continued as heretofore until active duties again call me into the field.

Among the useful results of these researches may be mentioned the determination of the compaeitum and consequent value of numer- ous specimens of iron ore, either from localities already known and resorted to by the furnaces of the state, or from such as have been discovered in our explorations, and which bold out the promise of beooming valuable at a future day, when the importance of this

brandi of mannfactare shall be sn appreciated as to attract a just share of the growing enterprise of the community.

As another contribotion to oar practical knowledge of the re- Boarces of the state, of no inconsiderable importance in connection with the agricnltaral improvement of a large district, as well as with the constraction of some of the public works now in progress, I would also mention the comparison, hj means of an extensive series of analyses, of the composition properties of numerous varieties of limeBtane found in the valley and farther west, and the determination of the chemical peculiarities which adapt them to be used as hydraulic cemenU or for other purposes.

In addition to these interesting branches of investigation, to which much care and labour have idready been devoted, and which we are stiU prosecuting, a multitude of analyses have been made of other materials of a more or less useful nature, comprising coals, marls, lead and copper ores, together with the waters of mineral q>ring8 and salines.

In regard to the graphieal department of our labours, it may be mentioned, that a large number of sections have been constructed, iUnstrating in great detail the structure and mineral contents of every portion of the territory in which minqte explorations have been carried on, and exhibiting all the modifications in the position of the strata presented at various points in each ridge and valley. These, as well as the sections previously drawn, are now undergoing revision, with a view to their reconstruction according to certain standard scales ; and it is believed, that with their aid, when thus perfected, together with that of the map, coloared geologically to correspond with tbem, little will be wanting to furnish a complete and accurate view of the mineral resources and geological structure of the extensive and intricate region to which they relate.

Observations for determining the alUtttde$ of the principal ridges and escarpments of the region we were exploring, were carried on during the season by means of the barometers and altitude thermom- eters provided for the survey. The latter instruments, from their portable form, and the ease of observing with tbem, were found to be particularly valuable especially m districts of a very rugged to- pography ; and of the accuracy of the heights computed from their mdications, sufficient evidence was obtained on several occasions by comparing them with the results of observations made with the level and the barometer, from which they did not differ in any important degree.

In relation to the progress made towards the formation of the public cabinets proposed in the law authorizing the survey, it gives me pleasure to inform the board that the specimens collected during tbe past season, together with the extensive gatherings of preceding years, are already of sufficient amount to form an illustrative cabinet of high economical as well as scientific interest. But as it is requisite to subject them to minute and repeated inspection, and often to chem* ical analyses, before they can be properly arranged and labelled, it has been found necessary to retain them within convenient* reach

suitably provided and equipped. A little later in the season two ad- ditionsd assistants were engaged, Mr. I. Slade and Dr. George W. Boyd, who repaired immediately to their respective tasks.

The subdivision of the region to which our investigations were principally directed into three districts, as adopted during the pre- ceding season, and referred to in my last yearns report, was retained with little or no modification, as best suited for the prosecution of further research ; and for a similar reason each of the assistants who had already been employed in this part of the state, was placed in the district which had been the scene of his labours during the pre- ceding year, and with the topographical and geological features of which he had become in some degree familiar. Accordingly, the northern district was assigned to Mr. Hayden, in coigunction with Mr. Slade— the middle to professor J. B. Rogers, assisted for a time by Dr. Boyd — and the southern to professor Aikin. To Dr. Boyd was afterwards allotted the duty of making a continuous examina- tion of the rocks along the western flank of the Blue Ridge, so in- teresting for the nnmber and extent of their beds of iron ore, and of extending his researches into the southern and northern districts, as well as making numerous sections across the mouQtain to its eastern base.

In addition to the researches thus prosecuted within the three subdivisions of the extensive region constituting the principal scene of our labours, some preliminary investigations were made towards the dose of the season, both in the coal bearing strata, extending from the western boundary of this region to the Ohio, and in the midland counties lying east of the' Blue Ridge. Aided by the re- sults of these and previous observations, we feel ourselves prepared to enter systematically upon the exploration of both these divisions of the state early in the next season, and it gives me pleasure to add, that the comparatively simple geological features they present, and the clear general views in relation to their structure and resources already acquired, will enable us to make rapid progress in the devel- opment of whatever is interesting or valuable witliin their limits.

In the ehemkal department of the survey the improved labora- tory arrangements referred to in the appendix to my last yearns re- port, have greatly facilitated our regular analytical operations, as well as Tarious collateral enquiries relating to the practical value and applications of some of the useiiil materials collected for examination. These researches, conducted by myself when not actively employed in the field, and since the close of our explorations prosecuted under my superintendence by two of my assistants, Messrs. Hayden and Slade, are still in progress, and will be continued as heretofore until active duties again caJl me into the field.

Among the useful results of these researches may be mentioned the determination of the eompasitum and consequent value of numer- ous specimens oiiron orcy either from localities already known and resorted to by the furnaces of the state, or from such as have been discovered in our explorations, and which hold out the promise of beooming valuable at a future day, when the importance of this

branch of roannfactare eball be so appreciated as to attract a Just share of the growing enterprise of the commtinity.

As another oontribotion to our practical knowledge of the re- sources of the state, of no inconsiderable importance in connection with the agricoltaral improvement of a large district, as well as with the constmction of some of the pnblio works now in progress, I would also mention the comparison, bj means of an extensive series of analyses, of the composition properties of numerous varieties of limeaUme found in the vallej and farther west, and the determination of the chemical peculiarities which adapt them to be used as hydraulic cemenU or for other purposes.

In addition to these interesting branches of investigation, to which much care and labour have already been devoted, and which we are still prosecuting, a multitude of analyses have been made of other materials of a more or less useful nature, comprising coals, marls, lead and copper ores, together with the waters of mineral springs and salines.

In regard to the graphical department of our labours, it may be mentioned, that a large number of sections have been constructed, illustrating in great detail the structure and mineral contents of every portion of the territory in which minpte explorations have been carried on, and exhibiting all the modifications in the position of the strata presented at various points in each ridge and valley. These, as well as the sections previously drawn, are now undergoing revision, with a view to their reconstruction according to certain standard scales ; and it is believed, that with their aid, when thus perfected, together with that of the map, coloured geologically to correspond with them, little will be wanting to tumish a complete and accurate view of the mineral resources and geological structure of the extensive and intricate region to which they relate.

Observations for determining the altitudee of the principal ridges and escarpments of the region we were exploring, were carried on during the season by means of the barometers and altitude thermom- eters provided for the survey. The latter instruments, from their portable form, and the ease of observing with them, were found to be particularly valuable especially ui districts of a very rugged to- pography ; and of the accuracy of the heights computed from their indications, sufficient evidence was obtained on several occasions by comparing them with the results of observations made with the level and the barometer, from which they did not differ in any important degree.

In relation to the progress made towards the formation of the public cabinets proposed in the law authorizing the survey, it gives ine pleasure to inform the board that the specimens collected during the past season, together with the extensive gatherings of preceding years, are already of sufficient amount to form an illustrative cabinet of high economical as well as scientific interest. But as it is requisite to subject them to minute aod repeated inspection, and often to chem* leal analyses, before they can be properly arranged and labelled, it has been found necessary to retain them within convenient* reach

while the necessary examinations and analyses are in progress, and it is deemed essential to the ultimate yalne of the oollection, that this temporary mode of disposing of the specimens he continned until the completion of onr explorations in every district of the state shall enahle ns to arrange them according to a uniform and oomprehensiTe system. Until such a final arrangement shall have heen made, founded upon a minute investigation of the entire collection when complete, and until some suitable apartment shall have been appropriated and fitted up for their reception, it is obviously inexpedient to commence the formation of the public cabinets in Richmond.

From the brief statement above given of the progress and present condition of the several departments of the survey, the board will readily infer the extent and number of the explorations and other enquiries already coitpleted. Fully to appreciate the amount of labour which has been requinte to bring our work to its present stage of advancement, they will bear in mind that a great part of the region in which we have been chiefly employed for tlie last two years, is not only remarkable for its ruggea and perplexing topog- raphy, but for an intricacy of geological structure almost without a parallel in any other portion of the globe, and that prior to our investigations, absolutely rufthing was known of the arrangement of its strata, or of the order in which its various mineral contents occur in connection with them. It should further be recollected that pre- vious to the chemical examinations forming a part of our enquiries, scarcely a single analysis worthy of confidence had been made of any of its limestones, iron ores, coals or other useful materials.

In presenting the following brief sketch of the geological por- tion and extent of the mineral resources comprised in the region already referred to as the chief scene of our labours for the last two years, I need hardly remark, that it is not my aim to gve an account of all the objects of interest in this vast territory, or even to include any considerable proportion of the details immediately referring to the tracts or districts of which I shall speak. A full view of our observations in this diversified region, even were it expedient to give so enlarged a form to the annual report, would prove of com- paratively little benefit to the public or to men of science, un- less accompanied by a map and numerous sections and other graphical illustrations exhibiting the several formations as they occur in appropriate geological colouring. What I am about to pre* sent, will tnerefore be rather an exemplification of the practical results to which onr minute and systematic researches have con- ducted us in one of the most interesting portions of the state, than a full account, or even a summary of the various facts and laws that have been ascertained in regard to its mineral structure and con- tents. At the same time, the information thus furnished will be found to be of high practicsl importance in elucidating the resources of this region, and in gaiding the researches of those who may be desirous of bringing them into use.

In relation to the plan adopted in drawing up this sketch, it should be remarked, that from the close connection that subsists

between even the minnte features of the geological structure of a country, and the position and value of the useful materials asso- ciated with its various rocks, it is impossible to convey clear rules for the direction of the practical explorer, without imoarting to him some knowledge of the arrangement of the strata and of their par- ticular attitudes in the hills and valleys in which he conducts his search. In this view, therefore, a few facts and descriptions of a purely geological character will claim attention as we proceed. But of these, no more will be introduced than are necessary to make our observations distinctly understood, as well as to confer upon them their just value as guides to the researches of those who may be dis- posed to turn them to account.

Sketch of the Geology of the Appalachian Region

OF VlBGIiaA.

The extensive area indicated by this title, is included between the western slope of the Blue Ridge, and a somewhat irregular line, marking the commencement of that portion of our series of rocks containing the bituminous coal measures of the west. The latter boundary lying a little westward of the lofty escarpment commonly known as the front ridge of the Alleghany, in the counties of Hamp- shire and Hiuy, and the larger part of Pendleton, is accompanied by less distinct topographical features as we proceed south. Ohang- ing its direction near the N. £. comer of Pocahontas county, it pur- sues a more westerly course, extending through Pocahontas, Green- brier, and Payette counties and preserving in its. various flexures the general direction of the irregular ridge designated on the map as Greenbrier mountain. Thence it pursues the line of the Flat Top mountain, and bending to the east, and again to the west, passes westward of Abb and Baptist valleys, and eastward of the sources of the Gayandotte and Sandy rivers in Tazewell and Russell coun- ties, after which, taking a direction parallel to the Stone and (Cum- berland mountains in Lee county, but a little to the north of the escarpment of these ridges, it passes out of the state into Kentucky and Tennessee.

Thii prolonged zone, thus passing in an inflected form entirely across our state, is continued on the one hand through Maryland, Pennsylvania, New Jersey, and a part of New York, and on the other, through Tennessee, and for some distance into Alabama, pre- senting throughout its course great constancy in the character and order of its several geological formations or groups of strata, but undergoing important changes in its topographical features as it ex- tends southward from the comparatively level region of New York into Pennsylvania and Virginia.

The eastern portion of this zone, constituting in oar state what is usually called the Valley of Virginia being composed chiefly of calcareous rocks, presents in general the beautifully undulating surface characteristic of regions in which such rocks prevail. In some parts of the valley, however, especially in the middle counties,

and as far sonth as Wytbe, tbe abroptness of tbe nndalatioDs, aod the loftiness of the knobs and ridges of limestone, give great bold- ness, and occasionally even mggedness, to the topography. The general undnlating level is likewise interrupted in several instances by long lines of lofty hills or mountains rising in the midst or near the margin of the limestone, and ranging parallel with the portion of the Blue Ridge immediately facing them on the sonth-east or south. These are composed of slates and sandstones later in our series of formations than the limestones of the valley, and strikingly contrasted in their contour with the subdued and graceful outline of the surrounding surface of calcareous rocks. Such are the Mas- sanutten ridges, including the Peaked mountain, which for a distance of nearly fifty miles, divide the calcareous belt longitudinally into the two valleys of the north and south forks of the Shenandoah. Such also are the Short Hill, House, Purgatory, Catawba, Tinkers, Fort Lewis, Draper's and Lick mountains.

Tbe subdivision of the Appalachian region lying to tbe west and north of the great valley, is every where marked by a bold and rug- ged topography. Numerous ranges of mountains, many of them of great length and imposing elevation, crowd this ample area. These all present the interesting and instructive feature of parallelism with one another, and with that portion of the Blue Ridge lying imme- diately abreast of them, changing their direction as it changes, and obeying not merely its great flexures, but even many of its minor and local variations.

The breadth of the Appalachian belt, including the whole space between the valley slope of the Blue Ridge and the commencement of the coal bearing rocks of the west, is preserved, with but little change, from the neighbourhood of the Potomac, nearly as far south as to where it is crossed at right angles by the New river in the X50untie3 of Montgomery, Giles, Mercer and Monroe. As measured on the map, from Westernport in Maryland, to Manasses's gap, and from the Little Sewell to the Bent mountain, as well as on several intermediate lines, its width may be estimated in round numbers at about 60 miles. Of this distance between a third and a half app>er- tains to the great valley or limestone zone on the enst. Before reach- ing the transverse line marked by the course of the New river as above referred to, an important change takes place in the valley front of the Blue Ridge. Expanding in the form of a wedge as we proceed from the neighbourhood of the Bent mountain towards the south- west, the ridge here forms a rugged plateau, including a part of Floyd and the whole of Grayson county. The eastern slope of this lofty table land preserves the previous general bearing of the mountain, while the western or valley slope, known in a part of its course as the Poplar Camp and Iron mountains, trends off towards the west at an angle with the former of about 25 degrees, impress- ing the snmo new direction upon all the ridges in the adjacent por- tion of the Appalachian belt. This change in the bearing of the strata, accompanied by n crowding of them against each other at high and very frequently inverted dips, is marked by a rapid and

fireat contraction in the width of the region ocoapied by the Ap- palachian rocks, 80 that here these strata aVe all included within a transverse distance of between thirty and forty miles. Estimated in round numbers the area of the Appalachian zone, as already de- fined, may be stated at about 16,000 square miles, or nearly one fourth of the entire surface of the state.

The several formations occupy ing this extensive and diversified region were described in the report of last year in some detail, ac- cording to the order of superposition in which they succeed one another, each formation being designated by a number marking its place in the series of formations counting from the lowest group of strata upwards. At the same time clear evidence was adduced of their having all been formed beneath the waters of a widely ex- panded sea, bounded along its eastern margin by what is now the valley slope of the Blue Ridge. To the deten dUtinct grovps of trata there described, each marked by some peculiarity in its niiner- alogioal character, organic impressions, or embedded rocks or ores, are hereafter to be added, as appertaining to tlie region westward and northward of this zone, a iuelfth formation consisting usually of a white siliceous conglomerate or coarse sandstone, and a thir Uenth comprising numerous beds of slate, grit, limestone and coal, out of which it may perhaps be found convenient ultimately to form an additional ot fourteenth group.

In tracing this vast series of deposits upwards from the Fand- stone covering the western slope of the Blue Ridge until we reach the highest stratum embraced in our western coal measures, we meet with no phenomena favourable to the view at one time enter- tained of a geological separation of the Appalachian from the coal- bearing strata. On the other hand, although there can be no doubt from the appearances exhibited at various points, especially in that portion of the Appalachian zone which extends into New York, that disturbing forces were occasionally called into energetic operation in some parts of this zone while the lower members of the series were forming in the bed of the ancient sea, the observations made in all parts of the region show so general a conformity in the superposi- tion of the strata, and so remarkable a correspondence in the min- eralogical and other characters of distant portions of each of the sev- eral formations as clearly to indicate the propriety of regarding them all as parts of one great series of strata accumulated as sediment oi otherwise over the widely expanded floor of the ancient ocean.

Referring to the report of last year for a detailed account of the several formations contained within the Appalachian zone, from the first to the eleventh inclusive, the following brief notice of the more prominent characteristics of each will, it is hoped, assist the reader in understanding the descriptions and illustrations hereafter to be introduced.

Formation I. — The lowest of the Appalachian rocks consists for the most part of a close grained white or light grey sandstone, in 0ome places containing beds *of a rather coarse conglomerate of

white Biliceons pebbles. Near the bottom in maaj ioBtances a brownish slaty sandstone occurs altematiDg with the former, while towards the top or approaching the next formation, the sand- stone passes into reddish and brownish and olive coloured argilla- ceous slates.

This formation in Virginia is exclusively confined to the western slope of the Blue Ridge and the narrow belt of rugged hills and mountains extending thence to the commencement of the valley limestone. Its chief importance in an economical point of view arises from the extensive deposits of valuable iron ore which it con- tains. These are mostly found high up among the reddish shales and therefore near the margin of the limestone.

Formation II. is mainly composed of limestones, and is the pre- vailing rock in the great valley lying immediately west and north of the Blue Ridge, imparting to that region its fertile soils as well as the undulating form of its surface. Of the external characters and the chemical composition of the more important varieties of these limestones, some account was given in a former report; since then numerous observations and analyses have been made confirming the opinion at tliat time advanced of the hydraulic character of those varieties containing a large proportion of carbonate of magnesia along with the carbonate of liine, and showing that the limestones of thb class are of very common occurrence in the valley, forming extensive belts and occupying no small share of the entire surface of this region. Occasionally the limestone assumes a slaty charac- ter, and in fact in Some places is actually replaced by slates more or less calcareous and of various tints of brown, grey, yellow, blae and green.

Associated with these calcareous strata, and forming a part of the same geological group, are heavy beds of chert or born stone, generally of a bluish grey colour, and varying from an open and ve- sicular to a compact texture, approaching that of flint or of chal- cedony.

In this group are found several varieties of iron ore, all of good quality, as well as the rich veins of lead ore wrought in Wythe county, together with less important ones in other parts of the valley.

Formation III. consists of slates and slaty sandstones of various shades of bluish black, lead colour, and yellowish brown, having a laminated and fissile structure and including thin bands of slabby limestone remarkably rich in fossils.

Formation IV. is composed of a white and purplish whit sand- stone, varying in texture from a compact fine grained rock nearly resembling quartz to a coarse conglomerate, and of red and brown sandstones graduating into ochreons shales. Valuable beds of iron ore occur in the upper part of this group, associated with the ferru- ginous and shaly rocks.

Formation V. is a group of soft ales and shaly sandstones gen-

erally calcareous, with ocoasional bands of ehalj limestone, and a compact white sandstone like that of Formation IV. The shaly rocks display a variety of tints — as brown, purple, yellow, green and lead colour — frequently presenting a mottiea aspect from the occurrence of blotches of green and yellow in the more massive iark brown strata. Associated with these shales occurs the remark- able f ossiliferous calcareous iron ore referred to in the report of last year. This, from its striking peculiarities, would of itself saffice to identify the present group were it marked by less distinct characters in other respects.

Formation YI. is made up of limestones, in which tiie shaly character predominates towards the bottom adjacent to the previous group, and the arenaceous towards the top, where it immediately miderJies the sandstone of the next formation. The limestones ex- hale a strong odour of bitumen when struck or rubbed, and are con- spicuous, especially in the arenaceous layers, for their extreme rich- neas in fossils. In this group highly magnesian limestones have been found at various points, which, like those of Formation II. yield a lime having the property of hardening under water. To- wards its upper boundary, a large admixture of siliceous matter in a finely divided slate converts the limestone into a species of chert or flint rock, and in some places the calcareous strata are almost en- tirely replaced by a material of this description.

Formation YII. consists almost entirely of a yellowish grey sand- stone, generally of rather coarse and open texture, and abounding equally with the preceding group in impressions of sheUs and other organic remains. Towards its upper boundary it has generally more or less of a ferruginous stain. Indeed this part of it, throughout a large portion of the Appalachian region, is the repository of con- tinuous beds of iron ore of immense extent, which often replace the sandstone for a great depth.

Formation YIII. is a group of slates and slaty sandstones, gen- erally occupying the intervals of ridges composed of the last men- tioned, ana often of several of the preceding formations. Where much expanded it rises into acute and wildly broken hills, seldom vicing with the a4}acent ridges in altitude, and well distinguished by their tendency to the conical or pyramidal form, and the conse- quent ierrated outline of their summits when forming a continuous range. This very extensive group, maintaining uniform characters throughout the northern and middle portions of the Appalachian zone, was subdivided in my last report into three portions — a lower, or black fissile slate, a middle or olive and green coloured slate, and nn upper or ochreous slate, of each of which a specific description was at tbe same time given. In a portion of the southern district, however, especially on the waters of the north fork of Holston, heavy bands of calcareous rock make their appearance in that por- tion of the group usually occupied by the olive slates, forming an im- portant expansion of the t<hin calcareous bonds occasionally met with

in the other districts of the Appalachian region in Virginia as well as in Pennsylvania, and rendering the formation of which I am now speaking strictly analogous to that in which the gypsnm and salt of New York are found. Owing to the vagueness of the lines of de* iiiarkation between the three subjacent groups in this portion of the southwestern district, and the almost entire absence in the lo- calities previously observed of formations YI. and YII. in the report of last year, the gypseous rocks of this region were referred to the upper portion of I0. V., which was supposed to have be- come greatly expanded in the southwestern portion of the Appa- lachian belt. But further observation having determined the ex- istence in some places of Yl. and YII., between the well charac- terized shales and fossiliferous iron ore of Y. and the slates and lime stones here referred to, and having furthermore traced the gradual change by which in proceeding southwestwardly the ordinary slates of Ylll. become more and more calcareous until they are at length replaced by important beds of limestone, the true position of these calcareous rocks in which the gypsnra of our southwest occurs is to be regarded as clearly and definitely settled.

In the lower part of this formation are found copperas and alum shales and an inferior variety of iron ore.

Formation IX. is characterized by red slates and sandstones of a rather argillaceous composition, alternating with shales and slaty sandstones of green, yellow, brown and dark grey colourings A more siliceous composition and harder texture become visible in this group as we proceed southwards ; at the same time the predominance of the reddish strata increases, so that midway in the middle district this variety includes nearly the whole thickness of the formation. Impure iron ore occurs in this member of the series, but in such small deposits and so rarely as to possess little or no economical in- terest. Of organic impressions it is also remarkably barren.

Formation X. is well distinguished by the coarse sandstones and conglomerates it contains, from the two widely expanded members of our series just described. Along with these more siliceous rocks and forming the upper part of the group are found olive, yellowish and dull red micaceous sandstones, graduating into shales, containing impressions of coal plants and thin seams of semi-bituminous coal. The association of tnese shales and coal in one group with the sub- jacent conglomerates and sandstone, is deemed boUi more natural and convenient than to regard them as the lower portion of the next superior formation, as from a limited examination of the rocks in question, was done in the last report. In fact the heterogeneouB strata of the formation now under consideration, mark the first effort of natural causes towards the production of the extensive series of sedimentary deposits and beds of coal forming the widely expanded coal measures of the trans- Alleghany region — an effort which was interrupted for a time by the new agencies employed in the forma- tion of the calcareous and other strata of the succeeding member of the series. It is in this formation that the semi-bituminous coal of

the little North monntain, Brnshy mountain, and varioas localities to be pointed oat, oocnrs, and thus the comparatively limited extent of these coal strata finds a ready explanation in the fact that during their formation the widely spread strata of the true coal mecuum had not yet began to be produced.

Formation XI. — This group consists of red and green and yellow- ish argillaceoas shales, and micaceous soft sandstones, the reddish strata predominating, together with bluish argillaceous limestone, the latter occupying comparatively little extent near the northern boundary of the state, but expanding to great thickness and cover- inc a wide area in Pocahontas, Greenbrier and Monroe counties, whence still farther south it again rapidly contracts.

Of this group the calcareoas rocks are the most interesting in a geological as well as economical point of view. Their generally ar- gillaceoas character is sometimes varied by the introduction of beds of chert, which as well as the limestone proper, are often extremely rich in organic impressions. A striking character of this limestone coasists in the spherical or shot-like forms of which whole beds of it are sometimes cbiefiy composed. This technically called oolitic structure has no where else been remarked in our series of rocks, excepting in some bands of the chert and cherty limestone of No. 11., of which a remarkable instance occurs in the strata forming the waUs of the natural tunnel in Scott county.

The upper portions of this group consist of micaceous sandstones, often closely resembling the soft grits of the true coal measures, but usually separated from them as we shall see by a well characterized conglomerate or coarse sandstone appertaining to the next formation. These sandstones are often marked with impressions of coal plants, and near their upper boundary usually contain a thin seam of coal.

Iron ore of good quality is found in the shales of this group. It is of the nodular variety, resembling that associated with the coal measareS occurs in the shaly beds in layers, alternating with the other materials of the strata.

In tracing the western limits of what we have for convenience sake denominated the Appalachian region, the line of boundary was drawn to correspond with the first outcrop or easternmost exposure of formation XII. In doing this, however, it was not meant to im- ply that throughout the area lying to the west and north of this line, none of the inferior members of the series appear upon the surface. Owing to the undulating directions of the strata in many instances, formation XL is brought up some distance to the west of the princi- pal escarpment of the Alleghany, beneath which it had disappeared. It is thus that it forms the principal part of the Cheat mountain and Laurel Hill, and overspreads a portion of Randolph county, and the region to the south and west. Eventually, however, it sinks finally beneath formation XII. and is no more seen within the limits of our great western coal region.

Formation XII. is a group of coarse grey sandstones and con- glomerates— the latter remarkable for the pertect smoothness and

rotundity of its pure white siliceoos pebbles. This conglomerate usaally forms the crest of the backbone of the Alleghany, and read- ily yielding to atmospheric agencies, strews the flanks of the ridge with the polished gravel thus separated from its parent ruck. Vegetable impressions are abundant in the associated rocks of finer texture, displaying themselves on the surfuoe, or forming deep cavi- ties in the mass.

Formation XIII. comprises that widespread series of sandstones, slates, limestone bands, and seams of coal constituting our western coal measures. As already intimated, convenience may hereafter require its separation into two formations. As yet observations Bumcientlj extensive and minute have not been made in the region occupied by these rocks, to warrant such a subdivision, or to render proper any special description of the strata where they have been examined. The detailed examinations about to be commenced in this portion of the state, will furnish the data for a judicious classifica- tion, as well as an accurate descriptive account of the several di- visions of the coal measures, and their valuable contents, while it is hoped they will greatly aid the explorations of the many enter- prising individuals now keenly alive to the resources of this portion of our state.

The following brief explanations of the meanings of certain tech- nical terms hereafter to be employed, wiU it is hoped, aid the reader not conversant with geological language, in understanding the sub- sequent descriptive account of the Appalachian region.

The simplest observation suffices to show that the rocks of the Appalachian belt present themselves in a variety of attitudes rela- tive to the horizon — in some places the successive beds or strata resting upon one another in horizontal planes — but in a far greater number of instances, more or less steeply inclined, and not nnfre- quently in a vertical position, here the stratum thus slopes into the earth, the direction of its slope is called its dip. Thus, much of the limestone of the valley sinks beneath the suiace in a direction which prolonged would carry it deep beneath the Blue Ridge. It is therefore said to dip totrards the eat.

It is evident that a line drawn along the surface at right angles to the dip would continue always upon the same stratum, provided the direction of the stratum longitudinally were preserved. Such a line is called the strike or hearing of the rock.

In passing acrow the edges of the strata as they are exposed upon the Rni*face in a direction perpendicular to the strike — we will pass to lower or to higher strata according as we proceed towards or from the point of the compass to which they dip.

In pursuing such a line it often happens that after passing over a series of beds dipping in a particular direction, we come upon the same series repented dipping in the opposite direction — the stratum at the point of transition being either bent over in an arched form to the reverse dip, or suddenly turned down and frac- tured so as to present one portion dipping in the one direction and

the other in the opposite. 8aoh an arrangement is called anti- elinal — and the line along which the change occurs is called an anti- clinal oxit. The anticlinal stractnre is also seen in a moantnin where the corresponding strata on its opposite sides dip opposite ways — and in most cases snch a mountain if cleft by the passage of a riyer will dilay the snocessive strata composing it in the form of an arch springing on both sides from its flanks.

On the other hand, when the corresponding strata dip towards in- stead of Jrom the central line — thus forming a long basin m which one stratum fits upon the other like a series of bowls or dishes of diminish- ing 8120— the arrangement is called syneltTialBJid the central line the iynelinal axis, Snch a structure existing in a moontain will dis- play the corresponding beds of rock in corresponding positions on the opposite slopes of the ridge, all dipping inwards towards the centre of the base of the monntiEiin, and will usaally be accompanied by the existence of a long trough-like valley on the mountain top.

By the intervention of a succession of anticlinal and synclinal axes, it is obvious that a given formation may be caused to over- spread a far greater breadth of territory than when the same dip is continued. In such a case the same strata are repeatedly brought to the surface and concealed.

The series of formations from I. to XIII. ns above described, are Qsnaily observed lying one upon another in the precise order of the numbers designating them, no matter in what directions the anti- clinal and synclinal tnms affecting them may cause them to dip. So that n. will rest upon I. either horizontally or in an inclined position ; III. upon II. and so on for the remainder. But some- times it wiU happen that the inclination given to the strata is so great, as not merely to throw them into a vertical position, bnt even to force them beyond it. In such a case the lower stratum will be brought to vest against the higher — so that I. may rest upon II., II. upon III., and so on. This arrangement is what is meant by an in- tenum of the dips, and evidently bespeaks extraordinary violence in the forces by which the derangement of the originally horizontal positions of the strata was brought about.

In some eases a deep cleft or fracture is found extending for some distance longitudinally among the strata, accompanied by the disappearance of some of the strata from the position they naturally occupy in the series — so that, for example, II. is found abutting against X. or even lying in an inverted position upon it — the inter- ▼ening rocks having been ingulphed by a downthrow along the line of fracture. Such a dislocation of structure is termed & fault, — of which, as will hereafter be indicated, numerous extraordinary examples are furnished in the Appalachian region of our state.

Geology of the Vallet of Viboinia.

The extensive zone comprehended under this title embraces all

that portion of the state having for its eastern boundary the west-

. em slope of the Blue Ridge and its inflected continuation, the Pop-

lar Camp and Iron mountains, and for its western, the Little North and a portion of the Big North mountain, with the southern pro- longation of the former, GaldwelFs and Brushj mountain ; and near its south-western termination the line of knobs forming the ex- tension of Walkers mountain.

Along its eastern margin, as already described, this area is occu- pied bj the rocks of formation I. constituting the ranges of broken hills which flank the Blue Ridge on the valley side, and forming the narrow belt of slaty rocks immediately adjoining the valley lime- stone or formation II. lying to the west. This limestone, with its associated bands of calcareous slate, and its beds of chert or flint rock, extends over most of the area ; thence to the western margin of the valley, broad belts of the slate of formation III., and moun- tain ranges consisting of this group of rocks, together with several of the formations stfll higher in the series, in some places interrupt the continuity of the limestone, and give variety to the scenery, soils, and mineral resources of this fertile and picturesque region.

Ooramencing our description with the narrow belt adjacent to the Blue Ridge, occupied by the sandstones and slates of formation I., I will next treat of the valley limestone or formation II., and thence proceed to sketch briefly the structure and contents of some of the more important ranges of mountains which arise in the midst of this generally level zone.

As stated in the report of last year, the sandstone of formation I. is occasionally met wiUi high up upon the flanks of the Blue Ridge, as at Turks and Browns gaps, and other points in that portion of the valley. At the Balcony falls, and for some distance to the north and south of the gorge through which the James river finds its way, this phenomenon is again exhibited, but throughout the greater part of its course we meet with the eastern limit of this formation much nearer to the base of the mountain. When lying upon the higher points of the declivity, its white siliceous strata form a conspicuous object in the scene, spreading downwards to the valley with a west- em dip, at first gentle, but rapidly augmenting in steepness, until along the mountain base, or a little further west, the higher strata of this formation are seen passing from their western dip into the vertical, and thence into an eastern and obviously inverted inclina- tion. This latter attitude is that most commonly observed in the innumerable rocky passes by which the traveller obtains access to . the main Blue Ridge. Such is the arrangement as yet found to pre- vail without an exception in the portion of the valley extending from the Potomac to the southern boundary of Page county.

At Harpers Ferry, and for some distance south, where the al- tered character of the sandstones and slates of this formation ren- ders it occasionally difficult to recognize the true dip, and even to identify the rock itself, this eastern declination is almost uniformly observed, the slates forming a portion of the bed of the Shenan- doah, dipping beneath the sandstone which rises in bold cliffs along its eastern margin, while the limestone of formation II. dips in the same direction beneath the slate, thus pointing to an inver-

Bioii extending entirely through formation I., and even affecting to a great distance the rocks of formation II. But this arrangement is even more strikingly displayed at Thorn tons and Swift run gaps, and along the path to the lofty peak of igneouS rock, called tbe Stoney Man, as well as in numerous other places along the valley flank of the ridge.

Of the peculiarities locally observed at Turk's gap and other neigh- bouring passes, some account was given in the report of last year. At the Balcony fails, where the western dips are preserved through- out a large part of the thickness of this formation, the most favour- able opportunities are presented for studying the composition and marking the arrangement of these rocks. The formation here rests upon igneous rocks, chiefly of the sienitic character, which, in this place, form the main axis of the Blue Ridge. These are well seen in travelling along the tow path of the canal which follows the coarse of the river through the wild and beautiinl gorge by which it makes its way from the valley eastward. As we approach the western termination of the pass, we mark the commencement of the rooks of formation I., which are seen on the side of the canal lying upon the sienitic mass with a N. W. dip. The lowest stratum, or that in contact with the sienitic, is a brownish decomposing slate, evidently mnch altered by its proximity to the igneous rock be- neath ; next is a greyish and reddish sandstone, then a slate similar to the former, then a repetition of the sandstone, again a slate, and at the termination of the gap heavy beds of massive white sand- stone, such as constitutes the type of this formation. The average dip of the latter, as presented in the imposing cliffs which guard the entrance to this pass, is 55° N. W. If now we return eastwardly by the road leading over the mountain, we are accompanied for a long distance by the strata just described, first losing sight of the upper sandstone, tlien traversing the slate, and thus successively passing lower and lower into the seiies, now spreading out its lower strata at a very gentle inclination even to the summit or nearly of the main ridge. Here, as well ns along the canal, striking evidences are seen of the modifying agency of the subjacent igneous rocks, in the vitreous character of some of the sandstones, the specks of chlo- rite and epidote, disseminated through them as well as the slates, and the jointed structure and confused stratification of all the lower beds.

Westward of this line of cliffs a low and level region intervenes, exposing, where not covered by the fragments of sandstone from the acQoining hills, a friable, reddish or brownish slate; of this mate- rial, Sailing's mountain, over which passes the road leading to the Natural bridge, is largely constituted. Here, as in most other parts of the valley, where they are exposed, these upper slates of forma- tion I. present a steep eastern dip, and rest upon the limestone simi- larly inclined lying to the west, so that, but for other observations, where the natural position of the formation is seen, comparatively undisturbed, it might fairly be inferred that the slates in question properly belonged to formation III. But such observations, taken

in connection witii the difference in the character of the two rocksi and the diatinctlj traoeahle inverBion of the more massive beds of formation III., clearly show these slates to be intermediate in posi- tion between the' well marked sandstones of I., and the limestone of II., and thus therefore, to be verj fairly included in an npper division in the former.

Phenomena similar to those here described, are found to prevail northward from the Balconj falls to some distance beyond Tye river gap, and at intervals as far as Kockfish gap. Southward from the falls, the expansion of the rocks of formation I. over the more ancient rocks of the Blae Ridge, becomes less and less, until in ap- proaching the road leading up Jenningss creek to the Peaks of Otter, we find this fortnation confined to the western base of the moun tain, whose granitic and sienitic rocks are widely displayed along the western slope as far down nearly as the valley level. Here the sandstones and slates of I. are all inverted, as are also the limestones as far as Buchanan, where they become vertical or tending to a western dip beneath formations III. and lY. of the Purgatory mountain.

Still further south, at Bufords gap, the lofty ridge over which the turnpike leading from Liberty to r incastle passes, consists en- tirely of the rooks of this formation, presenting however great modifications of structure and composition towards the central part of the mountain. This remarkable ridge has much the appearance of an irregular and contorted anticlinal axis of formation I., separat- ing that portion of the limestone and limestone shales of formation II. which occupies the valley about Buford's, lying to the east from the corresponding rocks to the west in the main valley of Virginia. At the western base of this mountain the customary inversion is displayed.

Thence along to the S. W. by the foot of the Blue Ridge and Pilot mountains, through the wild scenery of the Poor mountains and the almost inaccessible ridges of Macks mountain, and again along the base of Poplar Gamp and Iron mountains, the bold ex- posures of formation I. exhibit with scarcely an exception this same inverted dip, here presenting itself in lofty cliffs of sandstone conglomerate and slate in close juxtaposition with the rocks proper to the Blue Hidge. Towards the Tennessee line, a less entire inver- sion is discoverable, and in the Holston mountains, a little south of the line, vast masses of the lower beds of this formation are seen dipping northwardly into the valley. It may be proper to add that the Poor mountains and Macks mountain are composed almost ex- clusively of the rocks of formation I.

MiNEBAL Contents of this Formation.

Tlie white sandstone forming the principal and most conspicuous member of this group, from the closeness and fineness of grain, and the almost exclusively siliceous composition for which it is distin- guished, is generally well adapted for a durable building material.

Some of the layers however, of a less homogeneous oomposition, are liable to rapid disintegration, giving rise in some places to the abundant production of a beautiful wnite sand. This materiid has every quality suitable for the manufacture ofgloM. An inter- esting locality of this sand is to be seen in the vicinity of Darsts at the Balcony falls. Ascending a ravine penetrating the hill composed of the upper white sandstone of I. immediately in front of his house, we find the rock crumbling, and in some places appearing as loose sand, or but a feebly adhering mass. This sand is white, or but slightly tinged with yellow, and exists at the quarry in the greatest abundance.

But by far the most important materials associated with the strata of this formation are its irwa orea which are both rich and of in- exhaustible extent. These, as formerly stated, are chiefly confined to the slaty rocks next to formation II. — although another ore gen- erally of inferior quality, but which has sometimes been worked, is occasionally met with among the siliceous strata farther east. Of the importance of the ferriferous bands of this formation, it is hoped more just ideas will be entertained upon duly considering the pre- ceding descriptive account of the continuous extent of the for- mation itself as well as the further and more local details which follow.

In tracing the slates in question longitudinally throughout the whole length of the valley, fragments of iron ore and other indica- tions of the existence of valuable beds of this material are of fre- quent occurrence— not only in the vicinity of the mines which are or have been actually resorted to, but at innumerable other points, the heavy covering of stoney debris from the mountain, being the chief cause of the concealment of the massive deposits themselves.

The most northern point at which this ore is mined for the pur pose of manufacture is in the neighbourhood of the Shenandoah iron works. Near the Page and Rockingham line, it is procured from the shales adjacent to the limestone along the base of the ridge called Foxs mountain, composed of formation I. It is here found in great abundance, and is well adapted to the furnace. This ore is a hydrated per-oxiae of iron, generally compact and close grained, and exhibiting a smooth fracture. In some specimens it has the mamrailary and stalactitic character, and not unfreqnently pre- sents on its freshly exposed surfaces a beautiful play of the pris- matio colours. For its chemical composition, as well as that of the ores of other localities hereafter noticed, I would refer to a succeed- ing section of the present report

From this point southward to the neighbourhood of Mount Torrey in Augusta county, no ore banks are known to have been opened — although at nnmerous points along the eastern marn of the shales of formation I. unequivocal indications of good ore are to be met with. At the locality just mentioned, the remains of a furnace are to be seen, the ore for which was supplied, at least in part, from the same formation. Mount Torrey is itself a mass of the white sand-

stone, flanked towards the west by the Bhales which are here of little width, and soon ve place to the valley limestone.

From Mount Torrey the ore appears to continue almost uninter- ruptedly along the margin of the valley to a point S. £. of the Clo- verdale furnace in Botetourt county, and is mined to some extent in several places for the sapply of the contiguous furnaces. At t!ie Cotopaxi works, situated on the head waters of South river, and immediately at the western base of the low hills flanking the Blue Ridge, the massive white sandstone of I. is seen in vertical or in- verted sheets forming the western faces of these broken and pointed ridges, while a little west occur the shales, the repositories of the ore, with a south-eastern dip, and as usual, still more towards the west, the limestone. This ore which is a hydrated per-oxide, is irregularly stratified and remarkably various in its character — in some bands being quite solt and argQlaceous, in others almost pul- verulent, and in others again, nodular, or solid and compact.

The ore continues to show itself on the surface at intervals as we proceed in a southerly direction skirting the valley, and is found mingled in considerable quantity with the fragments of sandstone along the flanks of the hills situated immediately to the south of Buchanan.

Along the waters of Back creek to the south and west of this

?oint, the exposures of ore become numerous and highly interesting, he shales containing the iron, begin here to assume a character very commonly presented by them as they continue their course still further towards the S. W., that of blending with the limestone by numerous alternations of the shaly and calcareous rock. The ore is found in a line of hills consisting of these mingled rocks, sep- arated from the Blue Ridge by a valley of about three quarters of a mile in width, and extending in a broken form from about one mile east of Back creek to within two miles of Cloverdale furnace, being in all a distance of about nine miles. The summits and western slopes of these hills consist in great part of a deposit of the hydrated per-oxide of iron, brown and black, with some hematitic surfaces. The whole surface seems to be covered with the ore, projecting frequently in large masses. The soil is highly ferruginous and little or no rock associated with the ore. As well as could be judged, the breadth of this highly ferriferous belt is about three fourths of a mile, and as already mentioned, its length about nine miles.

A little nearer the Blue Ridge than the preceding, there occurs another variety of ore, associated with the sandstone of formation I. This is well seen at Bear Knob, and in a hill about one mile east of Mr. Woods. Along the western base of Bear Knob, are seen disintegrating sandstones and slaty rocks with a S. £. dip. These continue to the opposite side, though with a larger admixture of the sandstone, and at the summit of the ridge the ore occurs. The hill, near Mr. Wood's, consists of siliceous sandstone, sometimes white, though generally ferruginous and containing the ore in beds. Along its base, we meet with the ore in large masses, associated with the sandstone. It is also scattered profusely over the western

dediyity, generally in fragments of great size. This ore ib hemati- tic, and closely resembles that of the shales of the same formation. Higher up the hill toward the summit sandstone prevails again, associated with iron, and containing orystalized qnartz coating chal- cedony in a stalactitical arrangement The supply of ore to be ob- tained from this ridge would be abundant, but the quality is such as to produce a cold share metal, better suited for castings than for bar iron.

The continuation of formation I. along the southern margin of the yalley in the counties of Roanoke, Montgomery, Floyd, Wythe, Smyth and Washington, is accompanied by similar ores, and judg- ing by the indications upon the surface, and some of the more im- portant exposures which have been observed, in qnantities not less abundant than in some of the favoured districts heretofore noticed. At present, however, little or no use is made of any but the lime- stone ores of that region, nor indeed does it appear that the other ores have ever been resorted to, unless, perhaps, for a partial supply at the old Poplar Camp furnace. In Carter county, Tennessee, it is understood they are extensively applied, and it is hoped, that they may be made equally available at some future day to the growing enterprise of the neighbouring portion of our state.

The brief view that has now been given of the continuity of this iron bearing series of rocks, bordering our great valley on the east throughout its entire length, is calculated largely to add to our estimate of the manufacturing resources of the valley. For although numerous localities of the ore have long been known and resorted to, it is only by the evidence of this continuity, derived from a care- iul geological examination, that just views of the extent of this item of our mineral wealth could be obtained.

Of the Valley Limestone, aito its Mikebal Contents.

The rook here referred to constitutes the second in our series of formations, lying, where no violent disturbing force has inverted the natural position of the strata, immediately upon the upper shales of formation I. From the Potomac southward nearly to the Rockbridge line, it presents the form of two belts separated by an intervening tract of variable width, formed of the next or several of the next superior formations. As far sonth as the northern ter- mination of the Massanutten ranges, the dividing band is composed exclusively of the group of slaty rocks constituting formation III. Further south these mountains bear aloft still higher formations, resting upon a basis of the slates, and broadly skirted by them on either side ; and again after the termination of these ridges in the peak near Keezletown, the same zone of slate continues its course towards the south, gradually diminishing in breadth until it eventu- ally disappears. Similar interruptions in the continuity of the lime- stone rocks are produced by the Short Hill, Purgatory and other mountains in the more southern portion of the valley, but of these no particular description need here be given.

As already indicated, the prevailing dip of the limestone along its eastern margin where it joins the shales of formation I. is to the southeast. Indeed hat few instances occnr in the slate in which this rook is seen reposing in its nataral position npon these older strata. As might he inferred from the general prevalence of this inversion in the vicinity of the Bine Ridge, the nataral caoses hjr which it was hroaght ahoat exerted a powerial influence upon the position of all the rocks of the valley, and in some instances woald seem to have propagated a like inversion entirely across this zone and even into the rocks composing the mountain honnding it on the west. Of these agencies, however, it is not my purpose as it would not he appropriate here to speak in detail, desiring to con- fine my remarks to snch points merely as will aid in understanding clearly the structnre of the valley as connected with practical results.

While from the cireomstanoe just referred to the prevailing dip of the limestone even in the middle and western parts of the valley is towards the south and east, repeated alternations of dip present themselves in many parts of its surfiioe. Extensive lines of fault and numerous anticlinal and synclinal turns of the strata in axes parallel to the ridge may he traced throughout this space, and thus the true thickness of the formation, even where it exhibits no uncon- formity of dip from its eastern to its western boundary, wonld be very erroneously estimated by referring it to the entire breadth of the uniuterrapted calcareous zone. Of the limits of the several zones of limestone and intervening slate or other rocks, no accurate description can be verbally conveyed, the sections and geological de- lineations on the map, hereafter to be presented, being alone capable of indicating these boundaries with the reanisite precision.

As from what has already been statea it is apparent that the

grincipal band of slate (formation III.) running sou tn ward from the otomac lies in a synclinal axis, and as the same must be true of all other bandit of this rock bounded by the limestone on both sides, where no dislocation or fault intervenes, we may fairly infer that the bands of limestone in corresponding positions near the opposite margins of the slate will be found of like character, for in sncn cases they are in fact but parts of the same stratum extending in the form of a trough beneath the higher limestones and the incumbent slate. The importance of this rule in guiding to particular belts valuable either for their lime or hydraulic cement, or for the purposes of or- nament, will at once be perceived. It is true that the synclinal axis in question is far from being regular, and for a considerable distance presents inverted dips of the slate npon its eastern side, so as in fact to display only eastern dips throughout its entire width, yet even here the rule will be found of use, and corresponding belts will be found nearly similarly placed on its opposite sides. It is owing to this cause that the very same varieties of limestone are met with along the eastern base of the Massanntten mountiuns in Page county as along its western base in Shenandoah. In a fiimi- lar manner through the various anticlinal and synclinal turns of the

strata, the same belts of hydraalic cement or bine limestone or other varieties of the rock are sometimes frequently repeated. It is on this accoant as well as others that it becomes practically of much impor- tance to trace these axes, and to delineate them on the map.

Without entering into minute detiiils, I will now refer to some of the more important varieties of the limestone, including the hydraulic cement, and some of the other mineral contents of the formation of which I am treating. In doing this it may be remarked that inasmuch as the materials in question are geologically associated with this formation, it is not to be presumed that their existence is confined to the Valley of Virginia. In fact they are to be looked for wherever formation 11. occurs, and are hence, many of them, actually met with in those comparatively circumscribed tracts amid the mountains west of our valley, in which from the effect of a change in the dip of the rocks this formation is again exposed to view.

Of the limestones peculiarly rich in lime, and therefore especially suited to some of the economical uses to which these rocks are ap- plied, there are two varieties particularly deserving of notice. These are.

First, the dark blue limestone of a fine grain and smooth frac- ture, and

Second, the dun coloured limestone of a very close groin and semi-conchoidal or somewhat rounded fracture.

The former, though almost black before burning, yields a beau- tifnUy white lime, the colouring matter consisting of bituminous and other, combustible ingredients, which are entirely expelled by burning.

The latter yields an equally fair and rather purer hme. In both these varieties very little silica or magnesia is present, and in no case will they be found to furnish a lime capable of setting under water. At the same time they are admirably suited for the pur- poses of ordinary mortar.

In selecting these two varieties as particularly suited for cer- tain economical uses, it is not meant to imply that many others may not be found of suflSoient purity to render them valuable for sim- ilar purposes. The light blue limestone stained with red on its frac- tured surfaces, the bluish mottled limestones and others, though min- gled more largely with extraneous matters, yield a good lime, and may be usefuUy employed. In fact, so far as regards that most important of all the uses of lime, its application to the soil, I con- ceive that there is scarcely a single variety of the calcareous rock from which great benefits might not be derived when thus applied. Even the magnesian limestones, of which numerous and extensive bands have been demonstrated to exist in this as well as the higher calcareous formations, is no longer to be dreaded as injurious to the soil. An enlarged experience of the effects of limestones of this class has of late years clearly proved the error of the former opin- ion of their hurtful influence upon vegetation — and no better evi- dence can be adduced of the positive value of the lime furnished

by them in agricoltnre tlmn the fact, for whicb I can voocb by my own cbemical analyses, that some of the limes in most repnte in Pennsylvania and further north, as means of ameliorating the soil, are actually largely mingled with magnetia. The same fact has also been proved in regard to the lime manofoctnred in some

E laces in our own state, and which has been admitted from trial to ave proved useful to the land.

Many bands occur in this formation in the valley and further west, of a texture and colour adapted to purposes of ornament. Of these marbles for so they may deservedly be called, there are numer- ous varieties distinguiibed by their colour and other important qualities, a few of which I will here briefly notice :

First — The Dun Coloured Marble. — A rock of very homogeneous and close texture, and susceptible of fine polish. This is perhaps the most abundant marble of good quality in the northern and mid- dle counties of the valley. It is met with among other places, near New Market and Woodstock, and on the opposite side of the Mas- sanutten mountain in Page county, and has been traced a great distance both north and south.

Second — The Mottled Bluish Marble. — This, though rather less fine grained than the former, takes a good polish, and is quite orna- mental in its appearance. It is seen a little to the west of New Market, on the land of Dr. Ilenkle and may be traced for many miles.

Third — Grey Marble. — This occurs about three fourths of a mile from Buchanan, in a south-easterly direction lying very near the junction of formations II. and I. In approaching it from that

Eoint, as we proceed down the river, we first meet with ledges of Ine limestone having a high easterly dip, which, in the course of a quarter of a mile becomes vertical. It then bends over in an arch which is well exposed on the side of a cliff, and continuing for about half a mile along the road which is now directed more to the south as it approaches the line of contact with formation I., its character suddenly changes, and we pass from a dark blue limestone, with a steep south-eastern dip, to a body of compact fine grained marble, not stratified or distinguished by layers, but solid and massive, and as worn by the waters of Stone run, resembling at first a massive sandstone. Its colour varies from white to grey, the latter predomi- nating. The bed, as exposed on the creek, is about 50 yards in width, and it extends into the hills on both sides: course N. E. and S. W. A little further east the limestone becomes siliceous, and a few yards beyond gives place to alternate bands of a grey hard sandstone and dark green slate. About a hundred yards up the creek a bold ledge of white compact sandstone is seen coming down the mountain on the left of the road, and rising into the opposite bill. Its dip is south a little east ; angle 80

Fourth — The Whits Marble, — This variety is met with at sev- eral points in the valley, but nowhere else so abundantly, or of so exquisite a colour, and so fine a grain, as in Rockbridge county, at a distance of abont 6 miles from Lexington. As exposed on the hill

in which it ooonrs its thickness would appear to be abont 16 feet, and there is reason to think its extent lontndinally very consider- ,able. In susceptibility of polish, fineness and evenness of grain, and purity of colour, it can scarcely be excelled. A tendency to cross- jointing observed in the exposed masses, may interfere witli the quarrying of large blocks, but it is to be hoped that this defect would cease to prevail in the rock at some depth below the surface. Fifth — Bed Marble, — This variety, so far as yet observed, occurs only in the southwestern counties, and is almost entirely confined to the tracts of formation II. lying among the mountains to the N. W. of the valley. Throughout this portion of the Appalachian belt a great prevalence of red material may be remarked in many of the formations, and is highly conspicuous in 11., especially as it ap- proaches formation III., which is here deeply tinged with the same colour. In Giles county, a fine grained red limestone or marble is met with on the confines of III., near the base of AngePs Rest mountain, and a more compact and massive rock of the same hue in the neighbourhood of Chapman's ferry. In Scott county, a mot- Ued marble, in which this colour is pleasantly blended with greyish white, is found in great abundance, (a short distimce to the west of the courthouse). In the valley portion of this region the dun col- oured variety and others are also found.

Sixth — Shaded Marble, — This variety, found in Rockingham county, has been opened, and I believe wrought to some extent by Mr. Funks of that county. Its texture is compact and beautifully fine, enabling it to receive a good polish, and when thus pre- pared it displays a pleasing mixture of yellowish grey and slate colours.

The above account is far from including all the varieties or lo- calities of marble appertaining to formation II. as presented in the valley or further west — but will serve to shew that this formation is by no means deficient in the more ornamental descriptions of limestone.

The magneeian limestones constitute, both from their extent and economical value, a very important part of formation II., not only in the valley but in the districts lying to the west and north, in which this formation is widely exposed. They are usually distin- guished by a bluish grey tint, frequently blended with a tinge of yellow or brown, by a dull aspect, and a tendency to slaty structure. These are not, however, the only characters under which they are met with — for in some instances they present a dark blue colour. The best general guide to their recognition is the dullness of their surfaces, even when freshly broken, and the absence of the smooth fine grain of most of the pure varieties of limestone. No test, how- ever, merely derived from the aspect of the rook, will iiimish a cer- tain means for its identification, unless to the most experienced ob- server. The following simple chemical procedure is therefore rec- ommended as easily conducted and not liable to any ambiguity in the result.

Let a small portion of the rock be reduced to a fine powder in a

mortar, and upon this, placed in a cup or glass, ponr a portion of dilute sulphuric acid (oil of vitriol). Should the effervescence be slow and of long continuance, magnesia is indicated — for it is a property of the magncsian limestones to be less energetically acted on by an acid than the purely calcareous rocks. Allow the mixture to remain until the effervescence h&s entirely ceased, and is not re- newed by agitation. Pour the clear liauid off, and placing it in a cup, heat it gently until the greater part has been evaporated. Upon setting it aside, should magnesia be present, crystals of epS4)m salt will be seen to form, and in process of time will entirely replace the liquid. These may easily be recognized by their well known bitter taste.

The extensive existence of limestones of this class in the valley and other regions occupied by formation 11. is to be regarded as a discovery of some importance in an economical point of view— espe- cially when taken in connection with the fact recently established by numerous experiments in my laboratory — that the limestones of this and other formations containing a large proportion of magnesia are capable, when burnt, of forming a hydraulic cement. In my two preceding reports, in giving the results of some analyses of magnesian limestones from the valley, I suggested the probability that the valuable property referred to would be found generally ac- companying the presence of magnesia, and it gives me pleasure to be enabled now completely to confirm my former opinion by an ap-* peal to exact analyses of numerous specimens of these limestones, collected in New York as well sa Virginia, and to actual trials of their capability of furnishing a hydraulic cement.

Upon examining the cement rocks procured in New York from quarries in high repute and extensively wrought for the manufacture of hydraulic lime, as well as that used in the neighbourhood of Louis- ville, Kentucky, I have found magnesia to be one of their prominent ingredients, existing in them all in such amount as that the carbonate of magnesia bears to the carbonate of lime the proportion of about three to five. A precisely analogous result was obtained with the rock near Shepherdstown in our own state, long celebrated for yielding a valuable hydraulic lime, as well as with that of the North river near Lexington, of which some use has already been mode in the public improvements. A series of experiments with limestones similarly constituted as to the two ingredients above mentioned, and obtained from numerous other points in the valley, as well as in the country beyond it to the west, ond even from Loudoun county, has proved them to be endowed with the same faculty of hardening under water, and the trials still in progress with rerard to numer- ous other specimens, shown by analysis to be of similar composition, will, it is confidently believed, be attended with precisely similar results.

Without at present attempting to describe particularly the nu- merous bands of limestone of this character met with th rough rut the valley and at other points, I would merely call attention to this subject by enumerating the localities in which it was formerly

known to exist, and some of those in which it has heen discovered in the course of the survey.

1. Near Bhepherdstown on the Potomac extensive quarries have heen opened for many years. Here the rock rising from the river side to a height of nearly two hundred feet, admits of heing readily detached from the parent hed — and at the same time the water power and facilities of transportation immediately at hand render the position highly favourable for the manufacture and disposal of the cement. 8ome idea may be formed of the extent of the manu- facture at this place from the fact that five furnaces are kept con- stantly employed.

2. Extending southward from the locality above described, this band of magnesian limestone may be traced for many miles pass- ing near the villages of Charlestown and Millwood. Specimens from several points within this range, which have been analysed, have shewn the usual proportion of magnesia, and are hereafter to be submitted to the further test of actual exposure under water in the form of a cement.

3. A similar band is met with a little west of the western mar- gin of the great belt of slate dividing the limestone of the northern counties of the valley into two parallel zones. This as formerly in- dicated is but the repetition of the band which passes from 8hep- herdstown towards the south — here made to reappear by the syn- clinal structure of the slate and underlying limestone.

4. A third parallel band makes its appearance a short distance east of the base of the Little North mountain, being another repeti- tion of that first described, resulting obviously from the anticlinal arrangement of the strata of the western of the two limestone belts.

With regard to the rock of both these bands, chemical examina- tions are in progress at the present time — and of its magnesian character analytical proof has already been obtained.

5. Near Strasburg and Woodstock a similar band has been dis- covered, indicating by analysis the usual proportion of magnesia. Specimens from the latter locality have been submitted to the hy- draulic test, and have been found to form a lime having the char- acter of a moderately good water cement.

6. As might be anticipated from the synclinal structure of the Masaanutten mountains, the belt last described again rises to the surface on the eastern side of those ridges in Page county, and shows itself near Lnray, and at various other points. Specimens from these localities, though ascertained to contain a large proportion of mag- nesia, have not yet been submitted to the hydraulic test.

7. Specimens having all the external characters of this class of limestones have been collected from various points on each side of the band of slate forming the southern prolongation of the Afassa- nutten mountains. About a mile from Wyer's cave, and a fourth of a mile from the South river westward, near the residence of Mr. Daniel Murray, a band of the magnesian rock is met with, lying adjacent to a dyke of trap, the only mas of igneous rock intruded

among tbe limestones of the valley. This limestone has been found highly magnesian, and the lime formed from it becomes hardened nnder water. The same band stretches on to the sonth, and is seen some distance to the west of Waynesborongh.

8. A little N. W. of Stannton oocars a similar band, whose meg- nesian and hydraolic character has been established by actaal experi- ment.

9. Again, foar miles westward of Stannton, another band is met with, of which exposures may be seen on the road to the iron works. This has been foand highly magnesian and hydraulic.

10. Still further towards the west, and near the base of the Little North mountain, there occurs another belt of the same description, which shows itself at the Ohimney rocks, sometimes called the Cyclopean towers, Castle hiU, and numerous other places in a line

Earallel with the mountain. This also has been ascertained to be ighly magnesian and hydraulic.

11. On the North river above the mouth of Buffalo creek in Rockbridge county, are found extensive exposures of the mag- nesian rock, furnishing the material from which is made the hy- draulic lime manufactured at the establishment of Messrs. Graham and Edmondson. The breadth of the belt containing the hy- draulic limestones is here evidently of great extent, and the rock though always highly magnesian, presents much variety both in composition and external appearance. Several analyses will be hereafter given.

12. The Natural Bridge consists in part of magnesian limestone, some of which is eminently hydraulic.

IS. In the vicinity of Buchanan and Fincastle are found expo- sures of bands of the magnesian rock evidently continuous, over a long distance, but as yet their chemical and hydraulic examination is incomplete. Such bands also pass into and through Roanoke county, and are occasionally exposed in Montgomery, Wythe, Smyth and Washington counties. The magnesian limestone from near Christiansburg, reported upon last year, is ascertained to be hydrau- lic. The rock adjoining the lead mines in Wythe, and its continu- ation along the flank of the Iron mountain, is highly magnesian, and will without doubt be found hydraulic, and the same result is to be anticipated from the experiments to be performed upon the rock of analogous composition from numerous other localities in the south- western part of the valley.

As already stated, the magnesian and hydraulic bands of IT. are not confined to the valley, but are to be met with wherever that formation is somewhat extensively exposed. Thus in the wide lime- stone tract of Giles county — in Tazewell, Rnssell, Scott and Lee counties, where this member of the series overspreads a large ex- tent of surface, these bands may readily be traced.

Nor, as formerly intimated, is this variety of limestone confined to tbe formation in question. A locality of hydraulic cement in the Conoloway hill on the Potomac, which has been successfully re- sorted to for the use of the Chesapeake and Ohio canal, occurs in

formation VI., and a like material has been fonnd at other and dis- tant points where this formation is exposed.

Of the magnesian and hydraulic rocks discovered in localities not within the limits of the valley, but few have yet been subjected to complete investigation. For the present the following points in which they occur are deserving of our notice :

14. At Chapman's Ferry on the New river a rock of this de- scription of pretty good quidity is abundantly met with.

15. A similar rock occurs some distance below the ferry.

16. Another band is met with at Park's mill, also on the New river. Of each of these, the magnesian and hydraulic character has been amply tested.

17. In formation VI. one interesting locality has been submitted to the requisite tests. This is at the northern extremity of the gap at Crawford's mountain in Botetourt county. Passing from the limestone of formation II. as we enter this gap from the south, we next meet with a narrow exposure of formation III. forming the low slate hills by which the mountain is flsnked on that side. This leads us fairly into the magnificent gorge through which the James river finds its way from among the mountains into the more open region of the valley. Here we see on both sides of the river stu- pendous precipices of formation IV., presenting the strata at first entirely inverted, further west but partially so, along the summit and at the termination of the gap, nearly in a vertical position. Then comes a narrow and almost concealed band of the snales of formation V., and next we meet with the cement rock in the lime- stone of VI. It is highly magnesian, and yields a lime which for promptness in setting and final hardness can scarcely be surpassed.

The external peculiarities and chemical composition of the mag- nesian rocks above referred to, as well as of several others, will be given in a subsequent section of the present report. I pass now to

Tke iron ores of formation ILy of which, only a brief notice will be introduced.

Of these ores, several important localities have been long known and resorted to, but their quantity is by no means as abundant in this as in some of the superior formations. In the northern and middle counties they either have been, or still are, wrought near Strasburg, Port Republic, Luray, Mossy Creek, &c. ; and further 8outh at Graham's furnace and several minor establishments. The mines near Luray, from which ore is procured for the Isabella fur- nace, are situated about two miles west of the foot of the Blue Ridge, and within the confines of the limestone, although none of this rock appears either west of them or towards the ridge.

The beds of ore occur in clay, and only occasionally at the bot- tom of the lowest bed is the rock exposed. These beds are not strata interposed between layers of limestone, and cotemporary with them, but rather local and irregular deposits, formed at a later date in the clefts or cavities of the calcareous rock, and such in general appears to be the character of the ores of this formation

thronghoot the valley. At the mines in question, the ore is mostlj in a granalar state, slightly coherent, of a reddish hrown colour, and after heing carted to the furnace, resembles a heap of reddish earth. In other parts of the deposit it is qoite solid, and is extracted in masses of some size. When broken, they somewhat resemble hem- atitio ore, and contain much ochreons oxide. For their composi- tion I would refer to a fature section of this report.

A similar ore, highly esteemed for the metal it yields is found on Mossy creek in Rockingham county, under like circumstances to those above described, and again occurs contiguous to a part of the trap dyke before referred to.

Of the various other localities in this portion of the valley, and thence to the south-west no particular description is necessary at present. I will merely add, that they have been met with in Botetourt, Floyd, Montgomery, &c., and that in the most southern counties the extent of the deposit as mentioned in my last yearns report is very gi*eat.

In most cases the limestone contiguous to the ore is cherty or flinty, and sometimes the adjacent rook is chert itself.

Of the lead ore, snlphate of baryta, floor spar, Montgomery buhr, &c., associated with formation II. of the valley, I do not purpose to treat at this time.

Of the extent of formation III., in a portion of the valley, some account has already been given. It has been seen that this forma- tion, constituting a broad belt extending from the Potomac far into the middle counties of the valley, constitutes a great synclinal trough, the northern portion of which stretches far into Maryland, sustaining for a considerable part of its length in Virginia, the group of long parallel ridges, called the Maseanutten mountains. As we approach the Potomac, a little north of Smithfield, this broad zone of slate is divided into two bands by the interposition of an axis of limestone. Throughout this portion of the valley, the dips of the slate as well as limestone are uniformly eastward, and the general synclinal structure to which this slate belt is to be referred, can only be met with along the flanks of the Massanutten group of mountains. Even there, in numerous instances, the slate along the eastern base of the mountain, instead of displaying a western dip, is erected to a vertical position, or is even inverted.

Under like circumstances this formation is found constituting the trough-shaped basis on which the higher formations repose in the House mountains, Short Hills and Purgatory mountains. In the House mountains the slate forming the base and extending upwards about two thirds of the height, presents but gentle dips, so that the two successive formations of III. and lY. of which they are com- posed, are piled upon the subjacent limestone in nearly horizontal planes.

In the Short Hills the trough oonflguration is well marked, and a narrow anticlinal valley of formation II. intervenes between the east dipping slate of the western flank, and the west dipping slate that underlies the Gamp and Purgatory mountains.

The Pargatory momitain, where it strikes ont from the general direction of the North mountain, and extends obliquely aoross the ▼alley towards the Blue Ridge, is enclosed by steeply dipping forma- tion III., the eastern belt of which, near the termination of the ridge opposite Bacbanan is slightly inverted.

South of this the valley again opens, and is occupied by forma- tion II., with the exception of the irregular belt of slate lying west of Fincastle. Where tlie Tinker and Catawba mountains rise again to conceal the valley limestone, formation III. is seen skirting the former as it trends aer(m the valley, then bending around near MAiee*8 knob, and flanking the Oatawba mountain throughout its entire length. On the south-eastern side of this group of moun- tains it is seen continuing its course along the flank of the incon- spicuous ridge which lies at the base of the Fort Lewis mountain, and thus it passes on until it encloses in its narrow zone the whole of this mountainous area. Here, as in the case of the Massanutten mountains, the slate on the eastern margin of this region of irreg- ular synclinal structure is generally either vertical or overturned.

Draper's and Lick mountains are similarly encompassed by the slate, which on the eastern flank of the former is generally, and on that of the latter always inverted.

On the western margin of the valley a narrow belt of formation III. extends from the Potomac along the base of the Little North mountain, to its termination in Rockbridge county. It then bends westward a little south of the gap through which flows the North river, and again resuming its general course parallel to the Blue Ridge, spreads along the flanks of the Main North mountain and its continuation the Purgatory mountain, until it reaches the end of that ridge, where, bending abruptly round, it returns along its west- em flank until it rises in the high anticlinal ridge of the Garden mountain. From this point the portion of this formation apper- taining to the western side of the axis, trending southwardly and weetwardly, skirts the south base of Crawford's mountain, leaving now a widening space of limestone between it and the corresponding slate of Purgatory mountain. Keeping this direction it skirts Cald- well's mountain, and continues low down on the North or Brushy mountain to its termination in Washington county. Throughout the whole length of the Little North mountain, from its commence- ment near the Potomac to the gap of the North river in Rockbridge county, this flanking slate presents either a vertical or inverted position. In the Main North mountain in Rockbridge, for example, on the road from Lexington to Covington, the inversion is remarked only at the base, and as we ascend the dip changes from a steep to a gentle declination towards the north-west. The westerly dips are continued along the Purgatory mountain to near Buchanan, where, as before mentioned, there is a slight inversion. Along Crawford's, Caldwell's and Brushy mountains, to its termination, the inversion is resumed. These particulars, besides being of importance in judging of the dip of the beds of iron ore found in some parts of this border of suite, are intimately connected with the peculiar

strnctnre of the Little North mountain, and its prolongation towards the south.

The soil of formation III., especially in sitaations where this rock forms the lower part of a mountain, as on the flanks of the Massaniitten mountain, the Little North and House mountains, &c., is distinguished by a high degree of productiveness, particularly in the growth of wheat. With a more open texture than most of the limestone soils adjacent, it unites the calcareous character in a suffi- cient degree to be useful, and perhaps its position low down on the mountain slopes tends to enrich it with fertilizing materials con- veyed by the rain from the surface above.

Of the mineral contents of this formation, iron are is by far the most important, and the only one I propose noticing at present.

This ore, where found occupies a position near the upper limit of the formation, and within a short distance of the lower bands of formation IV. As occurring in the Big Fort valley of the Massannt- ten mountain, and on the slope of GaldwelFs mountain, near the Ca- tawba iron works, it presents itlf in beds of great thickness and length. In the former case, throoghout nearly the whole length of the valley to its termination near Strasburg, traces of the ore may be found, while at Blackford's mines, where it has been extensively excavated for the use of a furnace near at hand, it presents a spec- tacle truly imposing, from the magnitude of the deposit in which the workings are carried on. At the latter place, the seam of ore gradaally sloping up the mountain as it proceeds south, may be traced for perhaps six miles with but little intermption.

Thee ores are the hydrated per-oxide, generally dark brown, either cellular or compact, mammilary, and often showing a play of colours. They are usually a little tainted with manganese, and furnish a brittle metal, which is yet held in high repute.

The Massanutten movnfainsy forming the group of parallel ridges stretching from the neighbourhood of Strasburg to the peak near Keezletown, in all a distance of nearly iifly miles, may be regarded as one great compound synclinal mountain tract resting in the trough of slate, of which the prolongations northward and south- ward have been traced in a previous part of the present report. The two principal ridges bounding it on the east and west display a generally uniform synclinal structure, the upper portion of each being composed of a coarse conglomerate, together with grey and pinkish sandstones of various degrees of compactness and fineness, all appertaining to formation IV. The eastern or Massanutten moun- tain proper, commences at the peak near M'Gaheysville, and con- tinues to the Luray and New Market road. Here it is rounded off and terminates in another peak like that at its southern extremity. At these two peaks the sides of the prolonged trough of sandstone forming the mountain, bend round so as to meet somewhat in a semicircular form, the slate at the same time folding around beneath. About a mile further to the north, and in the same line, begins another similar synclinal ridge which continues with great uniform-

ity to the Luraj find Woodstock road, being terminated at both ends in manner like the preceding. A third ridge now riseu, in the i*ame abrupt manner as the others, presenting the same rounding of the strata to form the end of the trough, and runs on with some irregiiiar changes of structure to nearly opposite Strasburg.

The western ridge commences six miles N. £. of New Market, and maintaining a symmetrical synclinal structure of formation IV. resting upon III. to its northern termination, ends near Strasburg.

Between these ridges, but much nearer to the western than the eastern, is a third, which commencing near Keezletown, but a little south of the peak, continues as a synclinal axis, then forms a ridge of east dipping sandstones, and after farther changes impossible to be described without a section, terminates opposite Strasburg.

The Talley situated between the eastern ridge and the middle one lust described, is called the Big Fort valley — that between the middle, here called KelPs mountain, and the western ridge is termed the Little Fort valley. In the former, immediately along its eastern margin, there occurs a dislocation or fault which brings to the sur- fieice a little of the limestone of formation II., which is used as a flux in the' furnace. Directly west of this, and apparently dipping be- neath the limestone, are dark slates of formation YIII. — beneath which, a liUle to the west, occurs a small band of formation VI., the intervening VII., if any be present being concealed. Next come the red shales and accompanying iron ores of V. — and these rest on the IV. forming the eastern slope of KelFs mountain.

The Little Fori valley is occupied by formation III. exclusively.

In both these valleys iron ore occurs in great abundance, not only in connection with III. as already described, but with V. — and is procured from both these formations to supply the two furnaces of Dr. Blackford and Mr. Buck, erected in tbe neighbourhood. The ore from V. is found to be peculiarly rich and valuable, and nmj be traced for several miles. Manganese also occurs abundantly in the Little Fort valley. Viewing the abundance and excellence of its ores, and the facilities of transportation which it is hoped will ere long be afforded this part of the state, this mountain region would aeem to be destined, at no remote day, to become a busy scene of manufacturing enterprise.

The Short Hill rises in Rockbridge county opposite Collierstown, and terminates in a line of knobs, which prolonged would stiike the Purgatory mountain some distance above its southern end. The valley between it and the Camp or Purgatory mountain, at first of conaiderable width, is rapidly contracted in going south, by the pro- longation of the latter ridge out into the valley. Throughout its entire length it consists of formation IV. resting upon III., which rises to some height upon its flanks. A narrow trough-like valley extends along the whole length of its summit, exposing the lower ponderous red slates of V., accompanied by iron ore, of which frag- ments lire scattered abundantly over the surface, mixed with the de- composed shales. As is usual with the soil derived from formation

v., that of some parts of the valley in question is of good quality, and has been brought under cultivation on Barton's farm.

The Purgatory mountain commencing in the Camp mountain, displays for some distance south the regular synclinal structure, formation IV. resting on III., and both rocks on the western side dipping to the east, and on the eastern to the west. The dips be- coming gentler as we trace the mountain southward, the usual trough-like capping of IV. ceases to be exhibited about six miles above the termination of the ridge. Here and for some distance towards the south the summit of the mountain presents the upper slates of III. with a small and broken remnant of the lowest band of IV. — and it is at the junction of the two that exist those ample beds of iron ore, from which the Etna and Retreat furnaces were formerly supplied. Continuing south, the sandstone resumes its place, and the dips now rapidly steepening, the massive strata of this rock are seen folding together, until at the end of the mountain, near Buchanan, they are pressed into a vertical position between enclosing buttresses of formation HI., which, also in a crushed state, is folded around the abrupt termination of the mountain.

Of the extent of the deposits of iron ore above referred to, as also those situated under similar geological circuinstances on the west and east flanks of the mountain, the most ample evidence has been procured. At the upper bank before alluded to, the whole top of the mountain appears to be composed of it, and in numerous other places near the junction of formations III. and IV., indications of large deposits are to be met with.

The group of mountains still farther south, including the Tinier, Catawba and Fort LewUy is bordered, as already described, by a nar- row belt of III. passing entirely around it. Along the Catawba side this rock supports a rim of formation IV., dipping, conformably with the slate beneath, in a southeasterly direction, so as to pass under the rocks occupying the inner area of this mountain tract. This sandstone forms the eastern slope of the Catawba mountain, and presents in many places wide exposures of smooth grey rock, almost destitute of vegetation, spreading with a regular inclination down to the thickly wooded valleys of Carvin's and Mason's coves. A little north of McAfee's knob, opposite the Catawba furnace, the slate and overlying rim of sandstone suddenly bend around to the east and form the low ridge which leads to the vicinity of Cloverdale furnace. At this point it again makes a sudden elbow, and thence passing a little west of the Botetourt springs, forms the Tinker mountain, and its low inconspicuous prolongation along the eastern base of the Fort Lewis mountain. The structure of these two por- tions of the enclosing ridge is marked by very interesting phe- nomena. The transverse one presents its strata much dislocated, but shewing in the main a southerly dip, carrying them beneath the rocks of Carvin's cove, and the eastern displays a wall of formation IV., sometimes pressed over beyond the vertical by the band of slate adjoining it on the east. The area included within these

bonndaries is chiefly occupied by the rocks of VITI. and IX. Within the coves, and near the base of the slope of Oatawba mountain, small exposares are met with of the liiiiestone VI. as well as of Y. and YII. — bat owing to the dislocation along the eastern margin these are scarcely to be distingoished, and where seen are only exhibited in smaU amount, and in crashed condition. Even the massive beds of hard sandstone forming IV., here, as in other like instances of strnctnre, display the marks of those violent agencies to which they owe their present erect or inverted position, in count- less intersecting joints and surfaces, polished by the attrition of rock grinding against rock under the most enormous pressure. The Fort Lewis mountain really appertaining to the higher rocks is but a por- tion of the inner a/rea of this irregular synclinal tract, while the true boundary of the trough, upon the east, will be found in a low and here scarcely visible ridge, lying a little south and east of its base.

The highest formation included in this range or any where con- tained within the enclosure just described, is the group of slates composing IX., of which along with VIII. the Fort Lewis is en- tirely composed. This fact is itnportant to be borne in mind, as proving the hopelessness of attempts to discover any true coal seam within the limits of this tract.

In Draper's mountain still further south and west, a semi broken synclinal structure has been ascertained. The peak, near Newbem, forming one angle of the irregular trough, which, rapidly expanding in proceeding south, again contracts until terminated in that direc- tion by Hamilton's knob. A low broken wall of formation IV. ex- tends on the southeastern side from the peak to the knob, often exhibiting the inversion so often before referred to, while on the opposite side the bounding ridge of III. capped by IV. presents eastern and more gentle dips. Draper's valley, lying between these enclosing ridges, displays the higher formations to VIII., inclusive, but as in the former instance, V., VI. and VII. are inconsiderable, and the more level cultivated portion of this valley exhibits alone the slates of VIII.

The Lick mountain properly considered but a resumption of the synclinal capping of IV. after it has been lost in the short interval between Hamilton's knob and its northeastern termination, is a long and irregular ridge or group of ridges in which IV. form- ing the upper portion is often folded upon itself by the inversion of both ni. and IV. along the eastern side. In ascending the bold precipices of IV., opposite Wythe courthouse, called the Chimney rook, Uie eastern dip of the slates is well marked along the western flank of the ridge, and passing higher up the massive beds of white coarse sandstone belonging to IV. are seen lying upon the slate with a conforming dip, presenting by the projection of thin basset- ting edges that imposing wall-like cliff of rocks, from whose summit the traveller is admitted to a view of the surrounding region at once wide and beautiful and grand.

In both the Drapers and Lick ranges irmi, ore occurs at the junction of III. and IV., with every indication of being in valuable

amount. A looalitj especially deserviDg of notice is met with on the aide of the peak in ascending from Peak creek towards tbe summit. The ore displays itself in a massive bed at or near the commencement of IV., and is of highly promising qunlity.

Of the Rooks of the LrrrrjE Nosth Mouktain, and otheb Ridges Bounding the Valley on the West.

The Little North mountain throughont its whole length from the Potomac to near Jenningss gap, exhibits great uniformity of composition of structure, consisting on its valley slope of formation III., towards its crest of IV., and westwardly of V., VI. and VII. The tirst mentioned of these formations as already described, lies in an inverted attitude, dipping more or less steeply to the east. A like inversioD is found also to affect the rocks west of this form- ing the mass of the mountain, extending in some cases through- out the whole series as far as VIII., and in others, ceasing to operate at some intermediate point. In the latter case, the rocks generaUy consisting of V. VI., and VII. forming the western half of the ridge, display a western dip, increasing in steepness as they are nearer the eastern side of the mountain, until at length some of the strata are seen on end, and still fuilher towards the east the inTi'r- sion is exhibited in the whole or a part of IV., which is thus made to slope towards the valley and under III.

In general, the thickness of V., VI. and VII. as included in the structure of this mountain, though extremely variable, is much leas considerable than in the ridges lying towards the west. . The same is also true of IV., though not without important local exceptions. Extensive deposits of iron ore, such as accompany these formations when of greater thickness are therefore not to be Ipbked for gen- erally in the strata of this mountain.

Tlie extraordinary phenomenon of inversion presented through out this prolonged ridge, will be better understood in its several gradations by a brief reference to the arrangement of the strata at two or three points of easy access.

In the gap leading to the Augusta springs, after quitting the limestone of the valley (formation II.,) the last portions of which present an eastern dip, we remark the slates of III. lying conform- ably beneath them. Then follow the heavy red and white sand- stones of IV. forming the spine of the ridge and underlying the slates, next wo have the thin red shaly band of V., succeeding to which are tiie limestone of VI. and the sandstone of VII., all dipping in the same direction ; and last of all, we come upon the black lissile slate of VIII. from which the sulphuretted water flows, crushed and folded together, along the western base of the ridge. Here it is evi- dent the inversion has operated upon all the strata of the mountain.

At Brocks gap the same succession of eastern dips prevails aa far west as to tlie middle of VII., at which point a transition is ob- served from vertical to west dipping rocks, and the slates of VIII. which follow, lie with a west dip in their natural position upon VII.

At Green spring gap, Uedgesinlle, and nnmeroas other points acoesaible by tlie common roads, a similar partial or entire inversion may be readily remarked, and minute observations at all the inter- Tening points of the ridge have shown that this straoture pervades it every where.

Sontb of Jenningss gap it assumes a new structnre in which an irregular synclinal trough of IV. makes its appearance upon the mountain top, the western rim of which suddenly bent down into a steep west dip, forms the western slope of the mountain. Here IV. as well as the superior formations has become more massive, so that in the double as this synclinal trough is called, as well as near the western flank of the mountain, extensive and valuable beds of iron have been found, associated with IV., V. and VII.

The rocks of formation IV. now greatly augmented in thickness, appear with a comparatively gentle western dip at Streckler's gap, and spreading round towards the west beconie continuous with those of the Great North mountain opposite Lexington. Of the Purgatory mountain which is a continuation of this, some mention has already been made.

Commencing now at Crawfords mountain, with a partial inver- sion already noticed in alluding to the hydraulic limestones of VI., a great and prolonged dislocation presents itself. This first becomes distinctly evident at the point in which the road from Fincastlo to DibrelFs springs passes by the end of this mountain. For hero we find formation III. brought in contact with VII F., all the intervening rocks having disappeared, so that the road passes across the line of Crawford*s mountain without ever quitting slate rocks, though a .short distance to the right, the high cliffs of IV. are seen interposed between III. and the upper rocks. Southwest of this the extent of the dislocation varies for some distance but eventually increases so as to bring IV. or III. in contact with X. This lino of fault, one of the most extensive of which I have any knowledge, continues along the margin of the valley beyond the termination of the Hrushy mountain in Washington county, lying on the fiank or immediately at the foot of the mountain. Throughout its whole length the slate of formation III. lies in an inverted position on the southeastern dipping rocks of the ridge, which are generally formation X.

Of the Skmi-Bituminofs Coal op Sleepy Creek, Catawba,

Tom's Ckeek, etc.

The foregoing account of the structure of the mountain belt im- mediately west of the valley will be found of essential aid in illus- trating the geological relations and probable economical value of the seams of anthracite and semi-bituminous coal lying adjacent to the valley, and of which some mention has been made in previous reports.

It has now been ascertained beyond a doubt that the coal in question does not appertain to that part of our series of formations in which are contained the anthracite of Pennsylvania and the

bituminous coal of western Virginia and Pennsjlvania, and of the great western coal field in general, but that tbej are of mach ante- rior prodaction, being included in the tenth of our series of forma- tions, whereas the others are contained in the thirteenth. A great thickness of slates, sandstones and sometimes limestones correspond- ing to formations aI. and XII. intervenes between the two series of coal deposites, the lowest of which, that appertaining to having been as it were but a first effort, soon arrested, and productive only of one or two thin teams.

The following details, derived from numerous minute observa- tions, will sufficiently indicate the circumstances under which the coals in question are presented both in the Bleepy creek and Third hill mountains, and in the North and Brushj mountains.

Coal of Sleepy Creek and Thibd Hill Mountains.

These mountains may be described as forming the sides of an elevated synclinal trough of formations IX. and X., commencing about miles north of Puglitown, and continuing nearly to the Po- tomac, the Third hill composing its eastern and the Sleepy creek mountain its western boundary, lliroughout much of the length of the former a partial inversion of the strata consisting of IX. is found to prevail for some distance up its eastern slope, evidently referrible to the same mechanical forces which were instrumental in causing the inversion of the Little North mountain a few miles to the east, and of the rocks generally of the intervening space. Opposite to Green spring gap in the Little North mountain both the Sleepy creek and Third hill mountains consist of the red sandstones and shales of formation IX., having in the former a moderately steep eastern dip, while in the latter they are vertical or steeply west dip- ping nearly to the top. North of this the inversion of IX. in the Third hill becomes decided, the dips in the other mountain continu- ing as before. Near where the Bath and Gerardstown road crosses the trough, the elevation of both ridges is suddenly and largely aug- mented by the addition of heavy overlying beds of white sandstone and conglomerate appertaining to formation X. These continuing thus for several miles, are at length united in an elevated basin, in which, rebting upon the sandstone and conglomerate above described, are contained the slates and coal seam of which it is my chief ob- ject at present to treat.

At the most southern point at which coal hss been discovered, about 11 miles fom the northern end of the basin, an undula- tion or anticlinal wrinkle makes its appearance in the sandstone near the middle of the trough, and this structure is continued, form- ing a low broad hill, to the northern termination of the basin. At the same time the Third hill takes on a synclinal character, which it maintains nearly to its close. Thus, therefore, besides the general synolind structure of the two mountains, there are two important rolls, which, affecting the strata containing the coal, explains tiie numoer of exposures of the same seam in a transverse section pass-

ing thronirb the principal working near the northern end of the trough. There are foar of these exposures, two on the opposite ndes of the hill hefore mentioned and two on the Third hill.

The massive and ponderous sandstone forming the upper part of Third hill, thoogh thrown into very steep dips, has in general es- caped the inversion which affects the more flexible underlying rocks of IX.

The coal measures are well exposed near the northern extremity of the basin along the banks of Meadow branch, which for about three quarters of a mile flows in the synclinal axis, and eventually makes its escape through the wide opening at the northern extrem- ity of the basin, occasioned by the removal of the heavy sandstone and conglomerate by which originally the trough was there closed up. These slates and slaty sandstones, which are generally of a hard and compact texture and siliceous composition, and of bluish, greenish and grey tints,' show themselves in bold cliffs on the side of the stream dipping to the south in the middle, and towards the east and west sides of the basin passing into S. W. and 8. £. dips, so as to mark the curving around of the extremity of the trough. A little higher up the stream we meet with the black carbonaceous shales and black ffllioeous sandstones containing the coal. Numerous thin layers of coal are interstratified with the shales, and Uie seam which has been opened at this point is in places subdivided by an interpolated band of the black siliceous sandstone. As indicated already, the other outcrops of coal, both to the east and west of this, are to be regarded as belonging to the same seam as that here exposed, and there can be no doubt that it is this which is again exposed at the upper or southern opening before alluded to. This seam presents at all the exposures a very variable thickness, but may be estimated as pos- sessing an average width of about two feet of pure coal. This, as might be inferred from the indications of violence so plainly exhib- ited in the structure of the surrounding region, especially that of the Third hill, has been reduced to a fragmentary state, display- ing on the surfaces of spontaneous fracture marks of the pressure and attrition to which it would seem to have been subjected. The roof and floor of the seam present similar polished surfaces, and in some places have been pressed almost into contact. In such a crushed condition, the coal, though really as pure as anthracite in general, could scarcely prove of much value in the market, being unfit for the grate and most other purposes to which this class of coals is com- monly applied. Unfortunately, too, there is no ground for antici- pating any improvement, as the workings extend deeper into the seam. Were the broken state of the material merely the effect of weathering at the mrfacSy such a hope might be entertained, but feeling assured that it is the result of mechanical violence accom- panying the dirturbance of the strata at the time when they were thrown into their present positions, I entertain no doubt that this splintery character will be found pervading the seam more or less in every part.

The inversion of formation IX., already spoken of, continues af-

ter the closing of the basin, and is traceable across the Potomac into Maryland.

Coal of Narrow Back.

Immediately in the rear of the Little North mountain, in the counties of Shenandoah, Rockingham and Augusta there occurs a line of fault along which the inverted rocks of this mountain are found resting upon one of the formations higher in the series. While at some places, as at the Augusta springs and Brocks gap, this fault is merely a crush in formation VILI., in others it is accom- panied by the disappearance of several members of the series, thus causing IV. or even III. to fall upon IX. or X.

The latter condition is that prevailing along the eastern flank of the Narrow back. This ridge, composed of the siliceous conglom- erates and sandstones of X. dipping to the southeast, is bordered along its eastern base by the slate of formation III., so that the fault here having, along with the other intervening formations, removed the massive strata of IV., the chief frame work of the Little North mountain in this district of the state, this mountain is intermitted for a short distance in the neighbourhood of which I am now treat- ing. Towards the north, this rock again appearing east of the line of fault, the mountain is reproduced showing itself at Cooper's mountain near the Rawley springs, and in the same manner towards the south, the hiatus of rocks at the fault diminishing, IV. is brought up, and eventually, at the Augusta springs gap, exhibits all the formations from III. to VIII. inclusively, but in an inverted position.

Near the western base of Narrow back, on the margin of Briery branch, there occurs a low ridge, consisting of grey siliceous sand- stones, and dark blneish and greenish slates, appertaining to formar tion X. It is in these rocks that the thin coal aeam of this locality has been discovered, whose contents, as chemically examined, were noticed in a previous report. This seam is apparently about three feet in width, but for much of this distance consists of a black glazed sljale, readily mistaken for coal. As might be expected, from their contiguity to the fault above described, the coal and accompanying rocks are greatly contorted, the former being in a crushed and splintery condition, the latter displaying over extensive surfaces the polish due to a violent rubbing of adjoining strata.

Coal of Catawba Creek.

The line of fault, formerly described as commencing at Craw- fords mountain, presents a very slight dislocation at the gap by which the Fincastle and Sweet springs turnpike leaves the valley. Here III. and IV. are seen inverted in the low ridge adjoining the yalley, the latter being at some points greatly crushed. Immedi- ately behind we meet with VIII., which losing its inversion, forms the eastern side of the synclinal ridge called CaldwelPs mountain, which is here capped with trough-shaped strata of IX. Continn-

ing on to the nelghbonrbood of the Catawba fiirnace, the dislooa- tion shews itself on the flank of the mountain, bringing III. and IV. with inverted dips immediately on X. The coal seam opened in the latter formation displays the same irregnlarity of thickness, and the same splintered condition of its contents as the preceding. It yields about feet of coal, good in composition bnt not in merchantable form. At other openings in the vicinity, which it is understood are in contemplation or in progress, the same condition may be confi- dently anticipated. Yet from the general goodness of the coal, it is hoped that a asefol purpose will be answered by it in some of the operations of the aoining furnaces. Its calorific power and chemi- cal composition, as detailed in a former report, indicate its value as regards the material of which it is formed, and only the crushed condition pervading the seam here as elsewhere, and from which no extent of excavation is likely to find it exempt, prevents its being of importance as a merchantable article.

Coal of Bbusht Mountain, Stboubleb Rrx, &o.

The structure just described as prevailing along the eastern slope of CaldwelPs mountain in the vicinity of the Catawba furnace, is continued with slight modifications in the same direction to the ex- tremity of the Brushy mountain in Washington county. At Toms creek and other points where the coal seam has to some extent been explored, the rocks of X. forming the eastern slope of Brushy mountain, and occupying the low glades or hollows along its base are seen dipping at a very gentle inclination towards the south and east generally overlaid by the valley jlate, or formation III. The straightness and uniformity of the fault in this region, and perhaps the absence of the ponderous overtilted masfles of IV. may explain the fact that althongh much splintered and glazed by attrition, as in the case of the localities previously described, the seam as here developed is capable of furnishing some fragments of good size, and being at several points where it is exposed little intermixed with slate, bids fair hereafter to become of local importance for do- mestic and manufacturing uses.

The rocks and coal seams of Strouble's run in Price's mountain, being but an outlying repetition of the same strata in similar cir- cumstances as to structure and composition as those just described, require no more particular mention in this place.

Besides the real exposures of coal above noticed, all referrible to a single seam appertaining to formation X., and reaching witn some interruptions entirely across the state, numerous imaginary locali- ties of this material are met with in the valley and along its west- em margin. These occur in no one formation exclusively, but any where that a black shining slate may be exposed — and as bands of this description are frequent in VIII. and occasionally show them- selves in the slates of IX. and even of III. and I. — the fancied coal seams are very extensively diffused.

The details above given will, it is hoped, enable the enterprising

enquirer to understand in what position and geological circumstances the coal of X. occurs, and while guiding him to its discovery at points not yet actually explored, will repress unfounded expecta- tions regarding its probahle improvement in extent and solidity, at new points, or in the course of carrying forward the present explo- rations at the mines. It may be useful in this connection to repeat what hns already been stated more than once in my reports, that no true coal seam exists anywhere in the formations louer in the series than X — and hence, from the sketch of the structure of the valley, and various synchnal groups of mountains rising above its surface, except in the outlying X. of Price's mountain no such seam is to he found any where within that area. Of the economical importance of this determination a due sense will be entertained from considering the numerous fruitless expenditures of money and time it will pre- vent ; expenditures most usually incurred by those by whom they can be but illy spared, but whose sanguine credulity in regard to matters of mineral wealth, surviving repeated disappointments, can only be arrested by the positive determinations founded upon sys- tematic observation.

Composition of the Maonestan and Htdbauuo Limbstoxss op

THE ApPALAOHIAN ReOION.

It has already been stated that during the last two years, the numerous chemical examinations of the limestones of this region, and more particularly of formation II. have led to the two interest- ing discoveries :

First, that these limestones contain numerous and extensile hands in which magnesia is an abundant ingredient, and

Second, that these magnesian limestones yield a lime capable oj hardening under water, in other words, a hydraulic cement.

The importance of these determinations in an economical point of view, will, it is thought, be apparent without remark, from the various public as well as domestic uses of which hydraulic limes are susceptible, and to which they are applied. As a fact in science, the second of the two results, above announced, has the merit of establishing what has hitherto been doubted, and often confidently denied, the influence of magnesia in imparting the hydraulic char- acter. This influence has of late years usually been ascribed to the siliceous matter of the limestone— although very recently Vicat has been led to regard the magnesia as concerned in the effect. As in all the limestones demonstrated in my experiments to have marked hydraulic properties, the proportion of magnesia and lime is pretty uniform, we may hereafter be enabled, from an easy chemical ex-

J)eriment, to infer, at least probably, the hydraulic character of any iniestone, and be much more safely guided by the discovery of mag- nesia in the rock than by its general external characters, to the further trials by which practical certainty is to be secured.

In the following list of magnesian limestones, are included a few of which the hydraulic charact'Cr is matter of inference for

the present, bat to be tested at an early day. The others, properly prepared, have all been under examination for the last two months, and have evinced striking though not eqaal indoration, by contin- ued contact with water during that period.

The composition of two specimens of cement rock from cele- brated localities in New York, and of one from Loaisville, Kentncky, are added by way of showing their analogy in composition with the magnesian limestones of which I am now treating.

It may be proper to remark that the two specimens from Loa- donn county, though not within the boundary of the Appalachian region as formerly defined, are nevertheless believed to belong to formation II., which near the northern extremity of the Blue Kidge in our state, spreads to a short distance beyond it towards the east. But of the true character of this limestone, further observations are requisite before expressing a confident opinion.

1. Limestone from Reynolds's quarry near 8hepherdstown on the Potomac, said to make the best cement. Colour lead-grey with a dull earth lustre, fine grained and compact.

Compontion of 30 Grains.

Carbonate of lime, 15.94 grains.

Carbonate of magnesia, 6.49

Silica (or fine sand), 6.50 "

Alumina, tinged with oxide of iron, 0.64

Water, 0.12

Loss, 0.81 "

80.00 "

2. Limestone from the same locality as the above. Colour darker than the preceding, lustre the same, grain not so fine, com- pact. Makes excellent cement, according to my experiments.

Carbonate of Hme, 16.76 grains.

Carbonate of magnesin, 11.76

Silica, 0.77 "

Alumina tinged with oxide of iron, 0.85

Water, 0.13 "

Loss, 0.28 "

80.00 8. Limestone from Evitts run, miles from Charlestown, Jef- ferson county, on the road to the Sbannondale springs. Colour lead and bluish grey in streaks, dull and earthy aspect, fine texture, compact, irregular fracture. Hardens well by my experiments.

Carbonate of lime, 8.48 grains.

Carbonate of magnesia, 6.56 "

SUioa, 18.20

Alumina and oxide of iron, 1.20

Water, 0.40

Loss, 0.16 "

80.00 "

4. Limestone half way between Woodstock and Crabill's tav- ern. Oolour light grey, dull aspect, coarse grain, very bard and compact, rough fracture. Inferred to be hydraulic — to be tried hereatler.

Carbonate of lime, 14.00 grains.

Carbonate of magnesia, 10.10 "

Silica, 4.85 "

Alumina and oxide of iron, 0.54

Water, 0.15

Loss, 0.36

80.00 "

5. Limestone from near Woodstock. Colour light bluish and brownish grey, lustre dull earthy, rather close grained, compact. Moderately hydraulic according to my experiments.

Carbonate of lime, 1 5.83 grains.

Carbonate of magnesia, 11.84 "

Silica, 1.41 "

Alumina and oxide of iron, 0.74 "

Water, 0.14

Loss, 0.54

4(

30.00 "

6. Limestone from east base of Trap Dyke, Rockingham county. Colour light grey, the exposed surface approaching lead grey and of a dull earthy aspect, compact, fracture scaly. Moderately hy- draulic by my experiments.

Carbonate of lime, 15.52 grains.

Carbonate of magnesia, 12,88

Silica, 0.58 "

Alumina and oxide of iron, 0.25 "

Water, 0.12 "

Loss, 0.70

ti

it

7. Limestone from Chimney rocks also called the Cyclopean towers, 15 miles west of Staunton. Colour pale bluish grey, dull on the exterior, texture compact and rather slaty, fracture scaly. Higlily hydraulic by my experiments.

Carbonate of lime, 15.13 grains.

Carbonate of magnesia, 1 1.87 "

Silica, 2.00 "

Alumina and oxide of iron, 0.56 "

Water, 0.12 "

Loss 0.82 "

80.00 "

8. Limestone from hill near Staunton. Colour lead grey, in- clining to blue, exposed surface dull, and lighter tint than the in- terior, fine grained, and compact, sharp irregular fractare. Uj- draulic by my experiments.

Carbonate of lime, 17.44 grains.

Carbonate of magnesia, 10.03

Silica, 1.70 "

Alumina and oxide of iron, 0.26

Water, 0.18 "

Loss, 0.39 "

80.00

9. Limestone from 4 miles west of Staunton on road to iron works. Colour bluish grey, texture fine, compact fracture, sharp and smooth. Ilighly hydraulic by my experiments.

Carbonate of lime, 14.C4 grains.

Carbonate of magnesia, 11.24

Silica, 2.88 "

Alumina and oxide of iron, 0.47

Water, 0.11 "

Loss, f 0.66 "

30.00 "

10. Limestone from near Glasgow, east of Lexington, Rockbridge county. Colour reddish grey, texture close fine, aspect dull vitreous, fracture conchoidal. Inferred to be hydraulic.

Carbonate of lime, 17.86 grains.

Carbonate of magnesia, 9.87 "

Silica, 2.18 "

Alumina and oxide of iron, 0.25

Water, 0.08 "

Loss, 0.81

80.U0

11. Limestone from North river above the mouth of Bofifalo creek, Kockbridge county. Colour light grey, texture approaching fine, fracture scaly and rather rough, burnt for cement at quarry. Ilighly hydraulic by my experiments.

Carbonate of lime, 10.77 grains.

Carbonate of magnesia, 7.68 "

Silica, 8.07 "

Alumina and oxide of iron, 8.08

Water, 0.32

Loss, 0.18- "

80.00 "

12. Limestone from a band near the preceding. Colour dark blue, texture rather fine, fracture smooth with sharp edges. Slightly hydraulic by my experiments.

Carbonate of lime, 20.81 grains.

Carbonate of magnesia, 4.18

Silica, 8.81 "

Alamina and oxide of iron, 0.66 "

Water, 0.16 "

Loss, 0.89 "

30.00 "

Out of nnmerons specimens from this neighbourhood, none were found without a marked proportion of magnesia.

13. Limest<ine from Natural bridge and banks of Cedar creek. Colour blackish blue, texture compact, weathered surface earthy, fracture rough and scaly. Highly hydraulic by my experiments.

Carbonate of lime, 15.97 grains.

Carbonate of magnesia, 12.30 "

Silica, 0.86 "

Alumina and oxide of iron, 0.24

Water, 0.13 "

Loss, 0.50 "

80.00 "

14. Limestone from two miles beyond Christiansbnrg, towards Blacksburg, Montgomery county. Colour light eyish blue, texture rather coarse, tendency to lamination, fracture irregular. Inferred to be hydraulic — to be tried.

Carbonate of lime, 16.75 grains.

Carbonate of magnesia, 10.60 "

Silica, 1.96 "

Alumina and oxide of iron, 0.26

Water, 0.1 1 "

Loss, 0.34 "

(&

15. Limestone from near lead mines, Wythe county. Colour light yellowish grey, aspect dull earthy, rather compact, fracture un- even. Inferred to be hydraulic — to be tried.

Carbonate of lime, 16.29 grains.

Carbonate of magnesia, 13.29

Silica 0.06 "

Alumina and oxide of iron, 0.25

Water, 0.05 "

Loss , 0.06

80.00 "

16. Limestone from Chapmans ferry. New river, Giles connty. Colour light grey, texture granular, fracture rough, with minute shining specks. Highly hydraulic by my experiments.

Carbonate of lime, 18.28 grains.

Carbonate of magnesia, 10.78 "

Silica, 5.19

Alumina and oxide of iron, 0.60 "

Water, 0.10 "

L083, 0.10 "

80.00 "

17. Limestone from New river, a little below Chapman's ferry. Colour dark grey, lustre generally dull, with minute shining specks, texture granidar and friable. Highly hydraulic by my experiments.

Carbonate of lime, 16.08 grains.

Carbonate of magnesia, 18.10 "

Silica, 0.60

Alumina and oxide of iron, 0.14 "

Water, 0.09 "

Loss, 0.09 "

30.00

18. Limestone from Pack's mill. New river. Colour reddish brown, texture slightly granular, with minute shining scales, frac- ture rough. Quite hydraulic by my experiments.

Carbonate of lime, ', 14.71 grains.

Carbonate of magnesia, 7.47 "

Silica, 5.17

Alumina and oxide of iron, 1.71

Water, 0.22 "

Loss, 0.72

80.00 "

19. Limestone from same locality. Colour light grey, approach- ing yellow, texture somewhat granular, fracture uneven. Moder- ately hydraulic.

Carbonate of lime, 14.90 grains.

Carbonate of magnesia, 7.70 "

Silica 4.68 ",

Alumina and oxide of iron, 2.50

Water, 0.20 "

Loss, 0.07

'80.00 "

20. Limestone from Col. Taylor's, Loudoun county. Colour light grey, tinged with blue, texture compact, approaching cherty, fract- ure in one direction smooth, in the other irregular, exposing talcose films. Quite hydraulic.

Carbonate of lime, 17.0R grains.

Carbonate of magnesia, 1 1 .25

Silica, 0.31 "

Alumina and oxide of iron, 0.75 "

Water and loss, 0.61 "

30.00 "

21. Limestone from Mr. M'Uhaney's, Londonn coniitj. Colonr light grey, tinged witli green, lustre dull waxen, fractare sharp, ir- regular. Quite hydraulic.

Carbonate of lime, 18.42 grains.

Carbonate of magnesia, 7.50

Silica 7.82 "

Alumina and oxide of iron, 0.80 "

Water and loss, 0.46 "

30.00 Of the above specimens all but the two last are certainly from formation IL, and there is strong reason to believe that they are from the same.

I now proceed to give the composition of two magnesian lime- stones from formation VI.

22. Limestone from near the eastern side of Conoloway Hill, on the Potomac, Hampshire county. Colonr bluish, lustre dull, texture compact, inclining to fine, fracture scaly and rather rough. Quite hydraulic.

Carbonate of lime, 12.r5 grsins.

Carbonate of magnesia, 7.77 "

Silica, 7.28 "

Alumina and oxide of iron, 1.65

Water, 0.80 "

Loss, 0.37 "

80.00 "

23. Limestone from gap of Crawford's mountain, Botetourt county. Colour dark brownish grey, with stripes, texture compact slaty. Very highly hydraulic.

Carbonate of lime, 18.43 grains.

Carbonate of magnesia, 8. 17 "

Silica, 6.60

Alumina and oxide of iron, 1.60 "

Water, 0.18 ''

Loss, 0.07 "

80.00 " With the view of illustrating the similarity of composition of the preceding rocks with that of some of the cement rocks of established character abroad, the following specimens were submitted to analy- sis and trial :

24. Limestone from formation IL, Keic YorJk extensively burnt for cement. Colour yellowish grey, texture rather granular and friable, fracture rough. Sets well by my experiments, but not bet- ter than many of the Virginia rocks.

Carbonate of lime, 14.40 grains.

Carbonate of magnesia, 10.73 "

Silica, 3.63 "

Alumina and oxide of iron, 0.36 "

Water and loss, 0.82 "

30.00 "

28T

25. Limestone from formation VIII., New York, adjoining the gypseona shales. Colour lead grey, textare earthy and rather soft, fraotare slaty. Sets well by my experiments.

Carbonate of lime, 13.73 grains.

Carbonate of magnesia, 7.22

Silica, 6.38 "

Alnmioa and oxide of iron, 2.27

Water and loss, 1.14

30.00 "

26. Limestone from Lonisville, Kentucky. Colour dull bluish erey, slightly tinged with yellow, rather soft, fracture irregular. Said to make good cement.

Carbonate of lime, 16.51 grains.

Carbonate of magnesia, 7.25

Silica, 4.64 "

Alumina and oxide of iron, 0.79

Water, 0.37 "

Loss, 0.54

30.00 "

Thb Ibo27 Obes of the Yaixet and its Mountains.

In describing the geological structure of the Great Valley of our state, and of the mountains rising within it or forming its western border, some account was given of the localities and extent of the various beds of iron ore associated with its several formations. I proceed now to add a few chemical details in regard to the composi- tion of these ores, confining myself to those varieties which are of most importance, as well from the extent in which they are found as from their intrinsic excellence. Numerous other analyses of the ores in this region have been completed, and many yet remain to be executed, of which it is designed at a fiitnre day to make a detailed report Similar examinations have also been made of a large num- ber of ores associated with the strata of the mountainous region lying to the northwest, of which many are from the same forma- tions as occur in the valley. Of these general mention was made in the report of last year, in treating of the eleven successive forma- tions composing the Appalachian series. The minute investigation of the geological position, as well as the extent of the ores in ques- tion, zealously prosecuted daring the last year, has brought to light the important fact that throughout a large portion of the middle dis- trict of the Appalachian zone, as well as in various parts of its two other subdivisions, the most abundant, continuous and valuable de- posits of this material, are to be found in formation VIF. the coarse sandstone near its upper boundary being frequently replaced by the ore for a great thickness, and over a wide extent.

In announcing the discovery of the geological connection here mentioned, as one of economical interest, it is proper to repeat the remark often made on previous occasions in my reports, that such

a general fact cUims a high consideration for ntility from the extent of area over which it becomes applicable as the guide to indiyidnal exploration through all future time. To discover every accessible deposit of ore within the wide expanse of oar Appalachian zone, would obviously be impracticable with any scheme of geological investigation, however ample and complete. Ages must elapse before all the available localities of this widely disseminated mate- rial shall have been explored, yet, by determining now the law con- necting it in position with rocks conspicuously exposed and readily identified from the minute description of them already given, a safe guide is placed in the hands of the enquirer, with which and the geolugical details of structure, revealing the order and position of the formations in each ridge and valley, he can hardly fail in reach- ing a satisfactory result. On this account it was that muck, and perhaps a seemingly undue importance was attached in my last yearns report to the discovery of the foniliferotu and calcareout iron ore associated wWh formation V. Yet, of the practical value of this generalization, I may cite as proof that during the last season it has led to the observation in numerous places in the mountains of the southwestern counties, of the very same ore in the same geological position, when, but for the direction thus given to our enquiries, many of these localities would necessarily have been overlooked.

In the chemical details about to be presented, I shall follow the order of the formations, commencing with

The Ores of Fobmation I.

1. Iron ore from Foxs mountain 4 miles from Forrers furnace. Page (Rockingham, £d.) county. Colour dark brick-red or brown, fracture slaty conchoidal, texture uniform, rather fine, earthy, lustre dull, ochreous. Used at Mr. Ferrer's furnace.

Composition of 30 grains,

Per-oxide of iron, 20.60 grains.

Silica, 6.70 "

Alumina, 0.40 "

Water, 8.00 "

Lime (a trace).

Loss, 0.30

80.00 "

2. Iron ore from the same locality. Colour very deep brown, lustre shining, texture compact, fracture irregular, sometimes pre- senting a velvet appearance on the fresh surface. Very valuable in the furnace.

Per-oxide of iron, 28.93 grains.

Silica, 0.69

Alumina, 1.07 "

Water, 8.98

Loss, 0.38

80.00 "

8. Iron ore from mine worked for the use of Cotopaxi or M'CormickB faraace, Rockbridge. Nodular ore. Colour on the exterior light ochreons, in the interior dark chocolate brown, text- ure rather cellular.

Per-oxide of iron, 28.57 grains.

Silica, l.ro "

Alumina, 0.28 "

Water, 4.24 "

Loss 0.21 ''

80.00 " 4. Iron ore from MCormicks old bank. Colour dark Spanish brown, texture close grained, structure cavernous, fracture splintery. Not now in use.

Per-oxide of iron, 24.68 grains.

Silica, 1.70 "

Alumina (a mere trace).

Water, 8.47 "

Loss, 0.25 "

80.00 " 6. Iron ore from Kelly's bank used at Yesurins furnace. Colour rich reddish brown and chestnut, texture compact, though occasion- ally porous. Surface sometimes mammillary or covered with pro- jecting bosses and lustrous.

Per-oxide of iron, 24.27 grains.

Silica, 8.00

Alumina (a faint trace).

Water, 2.48 "

Loss, 00 "

80.00 "

6. Iron ore from Back creek near Buchanan, James S. Wood's lower bank. Colour dark chestnut, texture fine grained, structure cellular, fracture rough.

Per-oxide of iron, 24.16 grains.

Silica, 2.10

Alumina, 0.26 "

Water, 8.86 "

80.00 "

7. Iron ore from Back creek. Wood's upper bank. Colour of exterior dull black, interior dark snuff colour, texture fine grained and porous, sometimes mammillary and lustrous, occasionally crys- tallized.

Per-oxide of iron, 25.00 grains.

Silica, . 0.88 "

Alumina (scarcely a trace).

Water, 3.82

Loss, 0.0 "

30.00

Obes of Fobmation II.

8. Iron ore from Blackford's bank, Page county, used at the Isabella furnace. Colour light ocfareous brown, texture earthj, friable, light, mixed with slaty clay.

Per-oxide of iron, 22.19 grn.o.

Silica, 8.61 "

Alumina (a trace).

Water, 4.00 "

Loss, 0.20 "

30.00 "

9. Iron ore, one mile west of Lexington, Kockbridge countj. Colonr ochreous on the exterior, dark lilao brown within, texture very close grained, cellular.

Per-oxide of iron, 25.62 grains.

Silica, 0.78 "

Alumina (faint trace).

Water, 3.46 "

Loss,. 0.14 "

30.00 "

10. Iron ore, Limestone Hill, near north end of Short Hill, and contiguous to Buffalo creek. Colour light brownish yellow, texture earthy, porous.

Per-oxide of iron, 22.68 grains.

Silica, 2.97 "

Alumina, 0.69 "

Water, 8.61 "

Loss, 0.25 "

80.00 "

11. Iron ore near Read Reed, Ed.) creek Wythe county — Gra- ham's furnace — Honey-comb ore. Colour light brown, inclining to orange, texture fine grained, structure cavernous.

Per-oxide of iron, 24.61 grains.

Silica, 1.16 "

Alumina, 0.52 "

Water, 8.40 "

Loss, 0.31

30.00 " Ores of Formation III.

12. Iron ore, Blackford's mine, west side of Big Fort valley, Massanutten mountain. Colour dark brown, texture compact, structure largely cavernous, the hollows frequently filled with white siliceous clay surface sometimes mammillary, often iridescent or having a rainbow colouring.

Per -oxide of iron, 22.80 grains.

Silica, 8.15

Alumina, 0.80 "

Water, 8.06 "

Loss, 0.10 "

(4

13. Iron ore, Little Fort valley, Massanntten moantains. Col- onr dark brown, texture fine grained, generally quite compact, but sometimes cellular.

Per-oxide of iron, 20.70 grains.

Silica, 6.42

Alumina, 0.21

Water, 8.40

Loss, 0.27

14. Iron ore, top of Purgatory mountain, near Retreat furnace. Colour dark brown, texture porous and cavernous, the cavities oc- casionallj filled with siliceous clay.

Per-oxide of iron, 21.20 grains.

Silica, 5.20

Alumina, 0.73 "

Water, 2.73

Loss, 0.14

80.00 "

15. Iron ore, same locality. Colour dark chestnut, nearly black, texture fine grained, somewhat cavernous.

Per-oxide of iron, 24.06 grains.

Silica, 2.48 "

Alumina, 0.50 "

Water, 2.74 "

Loss, 0.27 "

80.00 "

16. Iron ore, east side of Crawford's mountain, near Catawba furnace. Colour dark chestnut brown, texture fine grained, cellu- lar, the interior of the cells being often coated with black velvet- like films.

Per-oxide of iron, 24.10 grains.

Silica, 1.97 "

Alumina, 0.16 "

Water, 8.68 "

Loss, "

80.00 "

17. Iron ore, same locality as preceding, more cellular variety.

Per-oxide of iron, 24.85 grains.

SUicA, 1.47 ''

Aluminfl, 0.12 "

Water, 8.98 "

Lobs, 0.08

80.00 " Obes of Fobmation y.

18. Iron ore, west side of Knobly monntain, near Paddytown gap, Hampshire county. Ooloor brownish red, texture soft and argillaceous, structure slaty, apparently composed of minute scales containing flat fossil impressions.

Per-oxide of iron, 20.50 grains.

Silica, 4.40 "

Alumina, 1.87 "

Carbonate of lime, 1.32 "

Water and Loss, 1.91

80.00 "

19. Iron ore, south side of PowelPs ridge, near the Fish-hook. Colour glossy reddish brown, texture soft scaly, structure laminated, arising from the multitude of fossil impressions.

Per-oxide of iron, 22.97 grains.

Silica, 6.16

Alumina, 0.67 "

Carbonate of lime a trace.

Water, 1.20

80.00 " Ores of Formation VII.

These, as already stated, are the most abundant ores in the moun- tainous parts of the middle district, being exposed almost in every ridge of which this formation composes a part. In the Big and Little North mountains, Brown's Hill, Tower (Tour, Ed.) Hill, Back Creek mountain. Brushy Hill, Biggs's mountain, AUens mountain, Potts's Creek mountain, Rich Patch mountain, Bratton's mountain, Mill mountain &c. &c, these ores are almost invariably to be found re- placing the upper strata of VII., and often of enormous thickness. Of the numerous analyses already made of them, two only will be here subjoined, as examples of their composition generally.

20. Iron ore, Bath furnace, east side of Bratton*s mountain nnd south of Calf Pasture river. Colour chestnut brown, texture com- pact, structure crystalline and fibrous.

Per-oxide of iron, 24.62 grains.

Silica, 1.22 "

Alumina (none).

Water, , 8.83 "

Loss, 0.83 "

8000 "

21. Iron ore, Brnsbj Hi]], A]]eghany county, Jordans mine. Colour delicato purplish brown, textnre very compact, strncture cavernous and ceilnlar, form tending to nodular.

Per-oxide of iron, 28.94 grains.

Silica, 2.22 "

Alamina (trace).

Water, 8.60 "

Loss, 0.24 "

80.00 "

Ee P O Et

Of The Pb0Orks8 Of

The Geological Survey

Of

The State Of Virginia

For The Year 1839.

Offiox of ths Boabd ov Public Wobks,

February 6th, 1840.

Sib, I herewith transmit the annual report of the geologist of the state for the past year, which 70a will please laj before the house of delegates.

This report relates to districts of the state not previously treated of, excepting incidentally in former reports, viz. : the marl region south of James river — a portion of the southern district east of the Blue Ridge, — and part of the great western coal region.

I am, very respectfully.

Your obedient servant,

David Oampbell, Prendent of the Board of Public Worh$.

The honourable the Speaker of the Houu ofDelegatee.

Report.

In oomplianee with the law requiring the principal geologist anntiallj to render an account of the progress of the geological sur- Tej, I beg leave to make the following report :

Section I.

The field operations of the survey were entered upon as usual early in the spring, and were continued without interruption from that time until late in the autumn. The weather throughout the season was in general favourable to our researches — and in some portions of the state scarcely a day occurred sufficiently inclement to compel a suspension of active operations.

The vacancy in the geological corps created by the resignation of Dr. W. E. A. Aikin, was filled as the board is aware by the appoint- ment of professor C. Briggs, a gentleman already favourably known as one of the geologists recently engaged in the survey of the state of Ohio. This gentleman entered upon his duties as a member of our corps in the beginning of June.

Keeping in view the importance of continuing the several assistants in the districts with whose geological features they were already in some measure acquainted, the various fields of research appofnted for the season's operations were allotted among them as follows :

To Dr. G. "W. Boyd was entrusted the continuation of the mi- nute researches in which he had been engaged during a part of the preceding year, in all that portion of the state embraced between the Blue Ridge and the head of tide which lies south of the range of Albemarle, Louisa and Goochland counties, comprehending in his duties the accurate tracing of the various narrow belts of lime- stone occurring in a portion of this region, as well as the determina- tion of the limits of the interesting formation of shales and sand* stones, prolonged in an irregular manner nearly through its whole extent and linking his observations from point to point by numer- ous local and some extended sections, exhibiting the various rocks in the order in which they occur.

Mr. G. B. Uayden was employed during the early part of the

season in exploring that diyision of the Tertiary marl region lyin south of James river — in which only partial researches had hitherto heen made — embracing portions of Norfolk, Isle of Wight, Nanse- mond, Surry and Green sville, together with the whole of South- ampton and Sussex counties. Having completed the allotted in- vestigation in this district, he was directed to continue the exami- nation of a portion of the Appalachian belt in Pendleton county, and thence to proceed to a systematic examination of that division of the western coal region lying between the front ridge of the Alleghany and the Laurel hill, embracing Preston county, together with portions of Hampshire, Hardy, Randolph and Harrison coun- ties.

In continuation of the enquiries commenced towanls the close of the preceding season, professor James B. Rogers, after completing some measurements of importance in the Mill mountain and neigh- bouring ridges towards the east, and carrying an accurate section through the lower extremity of the Falling spring valley, was chiefly occupied in the investigation of the upper members of the Appala- chian series of formations as developed on a scale of extraordinary magnitude along the eastern flanks of the Greenbrier, Sewell and Flat top mountains in Pocahontas, Greenbrier, Monroe, Fayette and Mercer counties, and in exploring the structure and contents of the widely expanded strata of coal bearing rocks incumbent on the for- mer, as presented in the Sewell and other ridges to the west, and along the valleys of the great Kanawha and some of the tributary streams.

To Mr. I. Slade was allotted the task of reviewing that portion of the Appalachian belt, designated in former reports as the southern district, with the design of constructing a number of additional sec- tions, rendered important by the peculiar intricacy of its geology, and of tracing with greater minuteness than had yet been done, those numerous remarkable dislocations, whose frequent and sudden changes of character are intimately connected with the development of materials of economical value, in their immediate neighbourhood, and are often essential to a knowledge of the structure as presented at points comparatively remote.

To Mr. Briggs was assigned the exploration of that portion of the coal region constituting the northwest district of the state, di- recting his attention for the present chiefly to the division of the coal bearing rocks hereafter to be described as the upper coal series, tracing the various coal seams and their accompanying strata as they successively present themselves on the Ohio and at other places in this part of the state — thence following them around as they curve across the southwest angle of Pennsylvania into Monongalia and Harrison counties, and marking the interesting mutations they un- dergo in penetrating more towards the east and south.

Of the diligence and ability with which the several members of the corps have prosecuted the numerous and often difllcult investi- gations thus assigned them, it ves me pleasure to be enabled to speak in terms of unqualified commendation.

Since the close of our operations in the field, our attention has been devoted as asual to the arrangement of the yarioos details col- lected daring the season, and to the graphical and chemical depart- ments of the survey. These labours will famish employment for mjself and several of my assistants nntil the opening of the next season, and will be continued as customary by myself until the pe* riod arrives for taking the field.

It gives me pleasure to state that in reviewing the labours of the past season, and comparing them with the amount of work yet re- quired for the completion of our researches, I am confirmed in the opinion, announced in my last year's report, that with the present oianization of the corps, an additional season for detailed investiga- tion, and a succeeding year devoted to a revision of some portions of the field, and to the tasks of preparing the sections and maps, as well as the final report for publication, will enable me to bring the ardu- ous labours of the survey to a satisfactory termination.

It is unnecessary to assure the board that I am truly anxious to complete the responsible task I have undertaken by the earliest prac- ticable time consistent with the accuracy, and therefore the Perma- nent inoportance, of all the economical and scientific results. That it has not been suffered to linger in my hands, must be abundantly evi- dent upon comparing the progress thus far made in our survey with that of similar enterprises in some of the neighbouring states. In- deed, bearing in mind the superior extent of our territory and its nneqnaUed variety, and perhaps complication of geological features, such a comparison will hardly fail to inspire a gratifying surprise that with means so much less ample we have been enabled to carry forward our enterprise with the rapidity and accuracy with which it has thus far progressed.

In expressing my solicitude for the early, but at the same time thorough completion of the work, I may be permitted to say, that berides the wish of rendering our results available to the public as promptly as possible, I am not uninfluenced by a desire to vindicate on grounds of utility the wise economy which first originated the survey, by presenting to my fellow-citizens what cannot be given in the annual reports, a detailed account of all its economical and scientific results, in a connected shape, and illustrated by an exten- sive cabinet of specimens, by numerous sections, and by a map of the state corrected in its topography, and geologically coloured. Nor will it be deemed unworthy the sympathies of the board or of the public to mention as an additional motive to expedition, the in- terest with which our labours in developing the diversined and often wonderful geological features of the state, are watched by the lovers of useful science in our own country and abroad — an interest, which kindly and cheeringly expressed, has not been without its efFect in lightening the toil and sweetening the pleasure of investi- gation. Were it necessary to adduce further evidence of the anxious zeal with which I have unremittingly laboured to forward the opera- tions of the survey, I might refer to the heavy expenses from year to year personally incurred in its behalf, without which it would

have been scarcely possible to have broagbt oar work to so advanced a stage as that to which it has now attained.

In selecting the districts npon which to dwell more particalarly in the present report, I have conceived it to be most proper as well as most agreeable to the board and to the public to make choice of certain important divisions of the state hitherto but slightly noticed in my reports, bat in which oar researches for some time in progress have at length been advanced nearly to their completion, and to occupy less time in the consideration of those of which general sketches accompanied with some prominent chemical and other lo- cal details have already been given to the public

Influenced by these views I propose omitting for the present farther particulars relating to the Appalachian region, of which some of the leading features have been described in my two preceding reports, and presenting a sketch somewhat in detail of the following districts.

1. That portion of the marl region situated between the James

river and the Oarolina line.

2. So much of the southern portion of the state lying east of the

Blue Ridge and west of the marl region as has been explored in sufficient detail to enable me to report.

8. The coal basins lying in tlie northern corner of the state be- tween the front ridge of the Alleghany and Laurel HilL

In addition to the systematic sketches designed to be given of these several regions, I propose to annex a brief outline of our ex- plorations in the valley of the Kanawha, and the lofty mountainous tract lying between the falls of that river and the western boundary of formation XI. in Greenbrier and the adjoining counties, as weU as of some of our observations in the northwestern coal region, in- cluding the tongue of land lying along the Ohio river, and between the states of Ohio and Pennsylvania.

It is scarcely necessary to say, that though thus silent for the present in regard to the Appalachian region, excepting so far as a portion of it may be incidentally mentioned in treating of the higher formations adjoining it on the west, our revisionary labours in that part of the field have been actively pursued, and with many inter- esting results. As regards our further operations of a like nature in this important division of the state, I would add that the minute measurements which have been begun, for determining the varying thickness of the several formations, an object not unimportant in its economical bearings, will be continued as far as our means allow, into other portions of the region. Our numerous sections will at the same time be knit together and rendered more minutely accu- rate ; the topography of the country will be more precisely deter- mined, by the accumulation of data derived from the measurement of the heights of our principal mountains at various point:*, towards which a good deal has already been done — and further disclosures will be made of the iron ores or other useful minerals described in preceding reports, as being associated with the several groups of strata forming the Appalachian xone. Tlie familiar knowledge we

now possess of the structure of eyerj portion of this region, facili- tates the progress of these measurements by guiding to suitable lines or points of examination. While connecting this accurate knowl- ecge of the structure and arrangement of the rocks, with the pre- cise determination of their thicknesses and the heights of the ridges in oar nnmerons sections, we are enabled to give that finish to the work alreadj performed, which will make our final representations

in a graphical shape creditable to the state and worthy the accurate spirit of modern geological research, as exemplified in the works of European geolots. v

In regard to the chemical investigations relating to the materials of this region, it is proper to say that a part of the labours of the laboratory will still be directed to the examination of the ores, lime- stones, or other interesting substances embraced in the Appalachian formations, and as will be seen in the sequel, a number of such re- sults will be included in the chemical division of the present report.

Section Ii.

Tebtubt Marl Region South Of The James River.

Ghapteb 1.

Sketch of the Boundaries Topography and General Geology the

iegion.

During the operations of a preceding season, a careful examina- tion was made of both sides of the James river, from its mouth as high up as the commencement of the primary rocks at Richmond, as weU as of all its tributaries for some distance inland ; and in my report for that year a brief account was given of the general results of those detailed enquiries, accompanied by a table of the composition of one hundred and sixty specimens of marl, of which sixty were from localities in the region south of the river. These enquiries having embraced the shores of the Elizabeth and Nansemond rivers, and Pagan creek, as well as of the Appomattox as high as Petersburg, our researches during the past season were directed to a minute exploration of the Blackwater, Nottoway and Meherrin rivers and all their branches, and an examination of localities remote from these streams, in which beds of marl were known or believed to exist. In prosecuting these labours, only a few interesting expo- sures have been left unvisited, chiefly in the inland parts of Prince George and Surry counties, and these will claim an early attention in the operations of the next season. Of the numerous specimens collected in the course of the seasons operations, nearly all have since been submitted to chemical examination, the results of which will be ven at the conclusion of this division of my report. With- out entering into minute detail in regard to the numerous extensive exposures of the Tertiary marl occurring throughout this region, I propose at present to give a brief account of its boundaries, and of

tbe order of snperposilion in which its well marked sobdiyiFions have been found to be arranged.

Tbe region bounded by the James river on the north, the Atlan- tic on the east, the state line on tbe south, and the irregular margin of the primary rocks on the west, may be regarded as consisting of two plateaus or wide benches of land, of which that lying towards the west preserves a general level much higher and less uniformly horizontal than the other. The latter extending from the sea shore to an inflected line lying a little east of the meridian of Suffolk, presents an unbroken plane, elevated from 8 to 12 feet above tide, rarely interrupted by ravines, and penetrated only by tidal creeks enclosed by shores which for the most part slope gently down to the level of the water. The absence of running streams incident to this feature in tlie topography of the country is supplied by the moving power of wind, which by its periodical flow, especially in the vicin- ity of the James river and the Atlantic, gives motion to numerous wind mills here in use. The surface of this extensive fiat, where not covered by swamps or morasses, consists of light coloured sands and clays, generally of a fine texture, and never enclosing pebbles of large dimensions. Beneath this the shell marl has been discov- ered only at a few points, and those situated near the eastern mar- gin of the higher plateau.

From SewalPs Point to the bay shore, and along that shore, as well as the coast line of the Atlantic, a more irregular topography prevails, caused by the sandy knolls or dunes accumulated by the combined action of the winds and waves.

These at some places, as for example at Willoughbys Point, are more than thirty feet in height, containing scattered shells and fragments, such as are found in the contigaous waters, which have been conveyed from the beach by the same transporting agencies that have heaped up the mounds of enclosing sand. On some of these dunes a soil has been formed capable of nourishing large trees.

As might be expected, evidences are frequently met with of changes having occurred in the outline of the beach, the roots of trees being seen in many places in shallow water at a distance of several hundred yards beyond the present line of tide, and at other points equally distant inland, under circumstances shewing that they once grew upon the margin of the beach.

The higher plateau lying to the west of the extensive fiat above described, extends from the line formerly indicated as a little east of the meridian of Sufiblk, westwards to the commencement of the primary rocks, maintaining a general level of from thirty to fifty feet above tide, and slightly rising as it spreads towards the west. Its boundary in the latter direction presents a very irregular wind- ing line, along which the marl and the primary rocks are seen alter- nately encroaching each upon the general limits of the other. In- deed at some points insulated patches or ridges of the former are seen rising through the marl at a short distance from its western limits, while at others little nooks or basins of the marl occur

almost completely enoiroled by the primary rooks. In uword, the form of the corioasly broken line which constitutes the boundary of the two is jnst each as might be expected from considering it as mark- ing the indented outline of a low rocky coast, washed by the tides of the primeval sea, beneath whose waters were slowly accnmnlated the successive deposits of shells and sand and clay, now forming the wide tract of land spreading eastward to the present margin of the ocean.

Excepting in the tracts lying near the eastern and western bonnd- aries of this plateau, the surface strata are horizontal and com- posed of sands and clays of a line texture, rarely intermixed with |)ebbles of considisrable magnitude. Unless in the immediate vicin- ity of the rivers, ravines are rarely met with, and even bordering on the streams the land gradually declines to the level of the water, or what is still more common, slopes gently down to the surface of a narrow flat through which the river finds its channel. Though as before remarked, the uniform level of this wide plain is in general maintained with bnt slight variations, there occur several low ridges and insulated hills, having a northeasterly and southwesterly direc- tion, but never attaining an elevation to render them conspicuous in the topography of the country. Of these there are two particu- larly interesting from their height and the light they reflect upon the relations of the several subdivisions of the Tertiary formation, the one stretching over the Nottoway river near the mouth of Not- toway swamp, across the tract intervening between that stream and the Blackwater, and following the direction of the latter, chiefly on its western side, the other extending in a nearly parallel direc- tion a little west of the Nottoway, and intersecting Three creek, Racoon creek, and Hunting quarter. The former of these low hills presenting on its eastern declivity an abrupt and on its western a gentle slope, attains a height usually from 20 to 80 feet above the level of the surrounding country ; the latter rises in some places to perhaps a greater elevation.

As already intimated, the usually unbroken character of the plain of which I am treating, is not preserved in the tracts adjoining its eastern and western margins. Along the former the high grounds overiooking the extensive flats spreading off towards the Atlantic, are deeply channelled by numerous and abrupt ravines, widening and deepening as they approach the lower plain. Above and along the sides of these the surface stratum, composed of coarse gravel and pebbles, often extending to a considerable depth, and arranged in layers frequently inclined at a steep angle, is seen resting npon the marl at various elevations, sometimes filling a cavity which is but the section of a ravine or trench formed by the removal of a portion of the shelly stratum before the coarse sand and gravel was poured in, sometimes occupying a coTtical hollow or pot hole penetrating many feet below the surface of the marl, and sometimes blending itself with the fragments of broken shells, such as compose the un- derlying strata. In a word, the coarseness of these materials, so dif- ferent tcom the superficial beds in the middle portions of the tract,

their steep and varying inclinations, and the deeply furrowed sarfaoe upon which they rest, combine in proving that along this margin of the plateau at one time, tides or currents, or most probably both, operated with great force, and that while as yet the lower plain situated towainls the east had not emerged from the ocean, this irregular escarpment of the higher level formed the barrier to the waves. Nor should it be deemed an unimportant fiict, in confirma- tion of this view, that along this line the beds of marl, especially the upper strata, are every where composed of /raffment$ qfihelU, often reduced to a mere shelly sand, and by a spontaneous process cemented into a species of fragmentary limestone.

Analogous phenomena are presented in the surface strata of the western margin of the plateau, where it spreads along the base of the low ridge of primary and other rocks bounding it on the west. Here we meet with a gravel of great coarseness often containing well rounded masses many inches in diameter, and all derived from the rocky strata situated to the west. These beds of sand and gravel of every variety of texture, as disclosed in the ravines, or in artificial sections, display the same obliquitj and frequent changes of direc- tion in their component layers which were before noticed, bat in a still more remarkable degree — and thus according to the observed and well known effects of currents, establish the fact that alon this line of boundary, and for some distance to the east, the agencies of tides and currents must at some former time have operated with great violence and effect. It may not be uninteresting to add, that the same evidences of an ancient coast line along which are seen the rocky fragments transported by wide rivers or sweeping inundations coming from the west, are found continually accompanying the narrow belt adjoining the primary rocks on the east not only in its course entirely across our state, but through Maryland, Pennsylvania and New Jersey. And I may further say, that owing to the more level surface of this than the adjoining rocky district to the west as well as the yielding nature of the sarfaoe strata, the great line of rail- ways now nearly completed from Oarolina to the northeastern extremity of New Jersey, pursues witli but few and short deviations the direction of this belt — thus affording to the traveller frequent opportunities of observing striking indications of the operations of those energetic currents which were once in motion along this ancient line of coast.

It would thus appear from the topographical and other features that have been described, that since the waters of the Atlantic flowed up to the base of the rocky ledge now marked by the lowest falls of our great rivers, entering its various coves and indentations and giving opportunity for the gradual accumulation there, as well as farther east, or more out from the shore, of the various strata of marl and other marine deposits found in their positions at the present day, at least two important geological changes have oc- curred.

Of these changes, forming epochs in the physical history of this portion of our state, and I may add, of a wide territory beyond it

towards the northeast and south, the first mnst ohvionsly have con- sisted in a cban in the position of the extensive tract adjoining the primary, and comprising the upper plateau above described, by which from being the bed of the ocean, it was converted into dry land — the second, in alike change, by which the lower tract was re- lieved of the incambent waters. By the first, the coast line was transferred from the edge of tiie primary rocks to the eastern escarp- ment of the higher plateau — by the second, from that escarpment to the present margin of the sea. It would be inappropriate here to discnss the question, whether these changes were brought about by a subsidence or retreat of the ocean, or by an elevation of the land, though local facts are not wanting in favour of the latter of these views in preference to the former — and in the view of geologists, to whom changes of this kind, in progress at the present day, as well as of ancient occurrence, are among familiar phenomena, it will scarcely l>e regarded as admitting of dispute. That these changes were rather abrupt than gradual, would seem to be evinced by the nearly aniform level over the surface of each plateau, and the very sudden alteration of level at the western boundary of each — neither of which could be anticipated under the influence of a slowly pro- gressive change in the relative level of land and water — causing, as it would, a gradual transfer of the coast line so as to cover succes- sively every portion of both tracts, and creating a gently sliehing surface from their western boundary to the sea.

CnArTBB 2.

Probable extent to which the Marl U spread out.

The entire area of the two planes above described may be esti- mated in round numbers at about 3000 square miles, from which for the present, deducting that portion of the surface occupied by the counties of Norfolk and Princess Anne, within which the beds of Tertiary marl, though as there is reason to believe continued be- neath, have as yet been reached only at one or two points, there will remain upwards of 2000 square miles of territory on the south side of James river underlaid extensively, if not uninterruptedly, by the shelly strata. The perfect continuity of these subjacent beds throughout the wide tract whose area has been mentioned, it would obviously be impossible to demonstrate — nor, judging by analogy, is it likely that such would be the condition presented by them were it possible to lay bare the level at which they repose. We might rather expect to find them overspreading numerous areas of greater or less extent, separated by spaces in which few or no shells had been deposited — while in some cases, at still greater depths, the spaces barren above would be found occupied by beds of marl, and the higher marl beds underlaid by unproductive sands and clays. But though these variations in the character of the subjacent strata may with reason be inferred to exist, the multiplied observations made in all parts of this region where exposures of mari, either nat- ural or artificial, could be met with, concur in showing that with bujb

moonsiderable differeooes as to depth below the general level of the plain, deposits of marl may be anticipated, if not at every spot, in every neighbourhood of any considerable extent. As examined along the Black water, Nottoway and Meherrin rivers, and their mi- meroas tribataries, both great and small, as well as at various points where exposures were presented at some distance from the streams, great general uniformity was observed both in the characters of the severiU strata of marl reposing in succession one upon the other, and in the depth below the common level of the surface of the surround- ing plain, at which eacb of the respective layers was placed. That in many portions of this tract, remote from the chief rivers by which it is intersected, few or no natural developments of the shelly strata should have been discovered, admits of easy explanation, when we bear in mind that excepting towards its eastern margin, and in the vicinity of streams, the uniform level of the surface is never inter- rupted by deep ravines, and that the shallow trenches occasionally occurring penetrate too little beneath the surface to reach the com- mon level at which the marl is usually found.

High up along the Nansemond river, and along the Blackwater, Nottoway and Meherrin, as well as their branches, a striking con- stancy is remarked in the position of that portion of the series of marl deposits called the blue marl, the lowest of the series as ex- posed in this and other parts of the area occupied by the Miocene Tertiary of the state. At almost every point where it has been ex- amined, excepting along the eastern limits of the plateau, where it gently dips beneath the level of the tide, not again to appear at the surface, this stratum may be seen skirting the water line in a slightly undulating band, and rarely rising to the height of many feet above the stream. In the southern portion of the tract this feature is most uniformly displayed, while near to the James river a decided rise of the strata may be discerned as we trace them westwards — thus bringing the blue marl and the incumbent portions of the series, where preserved, to a greater elevation above the level of the water — a feature yet more distinctly marked in the Tertiary districts lying north of the James river. The general parallelism thus maintained between the plane of the marl and that of the rivers throughout most parts of the southern tract, distinctly indicates a gentle decli- nation of the marl in a southerly direction, or that in which the Blackwater, Nottoway and Meherrin flow — and indeed it miglit with some reason be maintained, that the sloping of these beds in that direction, as well as the comparatively unyielding nature of the tena- cious days of which they are principally made up, have exerted an important agency in determining the drainage in that direction, as well as in preventing the streams from forming a deeper channel than is furnished a few feet below the upper suiace of these beds.

It will be inferred from these remarks, that throughout most of the area of which I am treating, the blue marl cannot be reached at depths much less than that of the level of the principal stream, and that explorations should never be regarded as unsuccessful until that depth has been attained. It may, I think, also be inferred from the

peculiar uniformity of position and character of these beds, that a ▼erT general, though not nnintermpted expansion of them would be found spreading awav from the margins of the streams to pass be- neath the highlands in which, from their level topography, no ex- posures have yet been found. Nor can it be admitted as presenting an objection to this very pleasing deduction from the facts observed, that no such general continuity of the strata is met with along the southern shore of the James river in tracing the Miocene marl from its most eastern to its most western exposure, comprising a breadth east and west of about 40 miles. The immediate basin of this river often presents for many continuous miles along the margin of the water, and even to some distance inland, deposits of sand and clay unmixed with shells, evincing in many places by the vegetable re- mains and other alluvial relics they enclose, that they belong not to the Tertiary formation, but owe their existence to the transporting and accumulating labour of the stream itself, in periods subsequent to that in which the Tertiary plain became dry land. The bluff-like line of hills by which we ascend from these flata to the level of the Tertiary plateau, are the true margin of the formation, as they would appear also to have been once the barriers that confined the ampler volume of waters that through the broad and winding channel wrought across the Tertiary plain found their passage to the ocean. Indeed, as observed in a former report, very inadequate ideas would be formed of the continuity and extent of the marl strata, from ob- servations on any of our great rivers, and to none is this remark more applicable than that which forms the northern boundary of the tract of which I am treating.

Of the probability that the marl is continued eastward beneath some parts at least of the low plain of Norfolk and Princess Anne counties, incidental mention has already been made, and the reasons for entertaining such a hope may not inappropriately be presented at this time. Lest, however, too sanguine expectations should be indulged of realizing so interesting a conjecture, it is proper to re- mark, that though diligent enquiry, aided by shallow borings at several places, was made throughout this region, and along the ca- nal and feeder and at other points within the Dismal swamp, no unequivocal deposit has yet been found excepting in the vicinity ot the Great Bridge in Norfolk county, and four and a half miles northeast of Suffolk near the western margin of the swamp. Of these the latter consists of blue marl, identical in character with the upper portion of that formation west. The former was of more ambiguous character, and for want of a sufficient variety of shells cannot yet be decidedly referred to a place in either of the members of the Miocene Tertiary hereafter to be described.

I have already stated that along the eastern escarpment of the Tertiary plateau, the blue marl, where in view, is observed to dip gently though irregularly in a direction which would carry it be- neath the low plain lying towards the sea — and as might be ex- pected, the overlying marly strata incline in a corresponding direc- tion. Thus in tracing these beds as exposed on the shores of the

Nansemond river, from the month of Bennetts creek, where they first appear, up towards Suffolk, the first exposures as they emerge aboe the water line are observed to consist of the fragmentary and yellowish marls, known to be higher in position than the blue. But bending westward, as we ascend, we observe the blue marl rising into view in the neighbourhood of Sleepy Ilole ferry, and after emercing a little higher, continuing generally exposed to the height of a few feet above the water line, throughout the reach of the river below Suffolk, having a north and south direction. So also at Day's Point, the most eastern exposure of marl immediately on the southern bank of James river, the shelly stratum that first emerges from the beach, at a short distance above the mouth of Pagan creek, consisting of the overlying bed of ferruginous marl, is seen gradually rising to a higher level as we ascend the river, until about a quarter of a mile aboe and in a direction N. W. from the point at which the marl first came in view, we see the blue stratum beginning to shew itself beneath the other, and soon with a gentle slope rising to the height of several feet above the base of the ri?er bank.

This general declination towards the south and east, along the ronrgin of the higher plateau, as well as throughout its whole ex- tent, as formerly remarked upon, can hardly fail to be regarded as favouring the opinion that the lower of these beds, to wit, the blue marl, is continued seaward beneath the contiguous flats, and though probably in general with increasing depth as it stretches towards the ocean, not too much removed from the surface to be accessible by moderate excavations along the eastern portion of this lower plain. But of the persistency of the npper light coloured beds of the marl beneath this tract, the probability is far less, as those destroying agencies, whether of tides or currents, whose traces are so deeply impressed along the ragged and channelled escarpment of the higher plateau, could hardly have spared these more superficial and less resisting materials.

Whether the shelly strata in question, should they exist beneath this tract, are within such a distance of the surface of any consid- erable portion of its area as to render the requisite excavations sufficiently cheap to be of economical advantage, can only be de- termined by a systematic exploration by means of borings at nu- merous places, carried to a considerable depth. These, from the attendant expense, and the time they would consume, I have not felt justifie<l in undertaking in connection with the survey, more especially too, as with some combination of effort among neighbour- ing proprietors, this simple operation could be conducted as success- fully by the persons immediately interested as by myself or any of the members of the corps. I cannot however dismiss this topic without suggesting the expediency of such borings in various places throughout the western portion of this tract, and tendering such assistance and advice as it may be in my power to give to those who may feel disposed to enter upon such an experiment. I wduld further suggest, that the probability of the existence of the marl

thronghont a portion of this tract does not appear to me the less from the absence of marl beds in the deep excavations made at the navy yard and dry dock in the vicinity of Portsmouth, for from the character of the strata there penetrated, they would seem to havoriginated as deposits from the neighbouring rivers, not likely to extend inland to any great distance, or should they be of more general occurrence, they might perhaps prove to be strata overlying the marl — in which event, however, its depth throughout that neighbourhood at least would render it unavailing for any useful purpose.

Ohapteb 8.

Of the Position and Limits offhe Eocene Tertiary as presented in

the Tract South of the James River.

The existence of strata appertaining to this the lowest and most ancient division of the Tertiary formation along the James river, as well as at a tQw points lying towards the south, was announced in the report of the geological reconnoissance of the state, and at the same time some details were given in regard to its character, as well as that of the overlying Miocene, as observed at several inter- esting localities on the southern bank of the river. Since that time, as will be seen by reference to succeeding reporto, its boundaries have been traced to the Potomac, and the characters of the various beds of which it is composed, in regard to mineral and fossil con- tents, as well as agricultural efficacy, has been made the subject of minute examination. Still more recently the limits of this forma- tion, as exposed on the James river, and traced southwards until it ceases to be revealed either in natural or artificial sections of the country, have been attentively explored. Of the general results of these otiservations, the following brief sketch will, it is thought, be deemed sufficient for the present.

In tracing the Miocene marl westwards by the numerous inter- rupted exposures in which it is disclosed along the southern bank of the James river, after passing a point a little above the mouth of Chipoaks creek, the strata contiguous to the river, and generally for some distance inland, are found to consist of sands and clays de- void of shells or their impressions, plainly referring themselves to the more recent class of deposits due in great part to the operations of the stream, and to that diluvial rush of waters, of whose agency numerous evidences are met with throughout the Tertiary plain. This feature is maintained along the shore as far as a point about ftbs of a mile below the mouth of Powell's creek, though at some distance inland both north and south of the river, as might be expected, exposures of the true Miocene marl are met with.

At the point just mentioned, the Eocene first makes its appear- ance in the base of the river bank, extending along the shore only for a short distance. It is of a light colour, quite indurated, con- taining impressions of shells, and occasionally an Eocene oyster. With some interruptions it may be traced westwards to near the mouth of the creek, gradually rising until it reaches a height of

about three feet. Thronghont this line of exposure the shellj stratam is generally overlaid by a ferruginous band from 8 to 18 inches in thickness, containing at many points small crystals of selenite or crystalized gypsum. This gypseous bed is covered by a layer composed almost entirely of pebbles, which may be regv'ded as marking the upper boundary of the Eocene, and upon this re- poses a bed of pipe clay ; the Miocene strata, seen at other points inland, as well as above on the river shore, having been removed in this vicinity by local agencies.

Still higher up, at Coggin's Point, Tarbay and Evergreen, the beds of Eocene are observed emerging at a greater elevation, and from the height of the river cliffs at several ulaces, an opportunity is afforded of viewing the incumbent beds of Miocene in the upper parts of the same exposure in which the Eocene is seen below. Of the principal features remarked at these interesting localities, some account having been given in a former report, their further and more detailed consideration will be omitted for the present. Still pursuing our course upwards along the river shore, we find numer- ous interrupted exposures. At City Point it is seen for a distance of several hundred yards rising a few feet above the base of the bank, presenting a dark brownish green colour, a sandy, micaceous and slightly tenacious texture, and containing a slight intermixture of sulphate of iron and gypsum, and impressions of shells, with lit- tle or no shelly matter. The green sand to which it owes its colour, besides being generally diffused, is seen occasionally collected into spots. Here, as at most of the other localities, the greenish stratum is overlaid by ferruginous clays and a gravelly bed, often assuming the character of a coarse ferruginous sandstone. Similar appear- ances are presented by these beds, as disclosed on the opposite side of the river at Herring creek, Berkeley, Shirley and other places, the lower stratum of a dark green colour being found to extend to the depth of many feet below the base of the bank, containing a considerable proportion of green sand, and abounding in impressions of shells, while the upper beds of the Eocene, where exposed along Herring creek, present a good proportion of shells in an undecom- posed condition. At Mr. Archers and Mr. Allens above Bermuda Hundred, the lowest strata of the formation are displayed at nu- merous places along the river shores, containing a few unchanged shells, and abounding particularly at the latter place in casts of the tnrreted shell usually found near the bottom of the formation. At Deephole, the most western exposure of the Eocene, immediately on the river, the marly bed consisting of an indurated light coloured calcareous clay, abounding in casts of the shell just referred to, after continuing at a level of 2 or 8 feet above the surface for a short distance up the river, is seen to rise at a considerable angle, until its lower boundary emerging from the base of the river bank, discloses a stratum of decomposing micaceous sandstone.

Here terminates the series of Tertiary deposits, so £ar as disclosed along the river. The sandstone in question marking the upper limit of a formation which is irregularly extended over the granite and

otLer primary rooks in tliis and the more northern portion of the state in the same meridian, refers itself bj the fossils it contains, as well as bj its position, to a class of deposits of more ancient forma- tion than any of the 2'ertiary group, and is dearly ascertained to belong to the later of the seetrndary clan of rocks, being not widely separated in the series from the strata of sandstones and slates asso- ciated with the ccal of Chesterfield, Powhatan, Henrico and Gooch- land comities. The upper surface of this sandstone formation, worn and broken in a yery irregular manner, and not unfrequently cov- ered with a layer of coarse pebbles, bears witness to the destroying energy of the currents whicn swept over it prior to the commence- ment of the Tertiary deposits, and thus marKs an epoch of violence in the early geological history of this region. It is on this account that these sandstones display remarkable irregularity as to thickness and texture, as displayed at intervals higher up the river, and in some parts of the belt over which they are generally spread out, they appear to have been entirely removed, permitting the lower Tertiary beds to rest immediately upon the granite.

South of the James river this irregularity in the subjacent secondary sandstone is much more strongly marked than in the northern portion of the belt as it extends with a variably increasing breadth across the South and North Anna and Rappahannock rivers as far as the Potomac. Hence, as might be inferred, the limits of the Tertiary beds towards the west, or where they join this older formation, present the most complicated sinuosities. Indeed islands and peninsulas of the sandstone are met with some distance east- ward of its general boundary, while inlets of the Tertiary strata are seen penetrating beyond it to the west. Thus on a branch of the Appomattox just above the fork near Broadway, on a meridian sev- eral miles to the east of that of Petersburg, these layers of coarse and fine sandstones and conglomerates are seen lying horizontally one upon the other, forming a cliff about fifty feet in height, while in the vicinity of Petersburg the greenish sandy strata of the Eocene are found. It may well be imagined therefore, that near its western margin the usual continuity of the Tertiary marl formation will be liable to frequent and sudden interruptions, and that from its exist- ence on one estate no argument can be drawn for its presence on that which lies contiguous and in* the same meridian.

This belt of sandstones, forming further north so important a feature in the geology of the western confines of the Tertiary tract, continues but a short distance south of the James river. Suddenly terminating, so far as superficial exposures are concerned, on the Appomattox in the vicinity of Petersburg, no indications of it are met with further south in its previous position, between the Ter- tiary strata and the ledge of primary rocks, and only in one instance has a rock resembling it been found in the country lying south of the neighbourhood of Petersburg. Neither, as far as I know, does it make its appearance in North Carolina. The insulated locality just referred to, is in the bed of the Nottoway river, about 4 miles above Boiling's bridge, where a rock forming tlie natural fonnda-

tion of a bridge, is exposed for a short distance nearly on a level with the water, bearing a close resemblance to the formation re- ferred to, and which there is strong reason for believing is geologi- cally the same. From the small area occupied by these sandstones on the surface of the tract south of the James river, as well as the frequent overlapping of the Tertiary beds, I did not deem it im- portant in describing under a preceding head the general character of the western boundary of the upper Tertiary plain, to advert to the small thickness of these rocks interposed between the marl and the ledge of primary. Nor indeed in any part of the state is such a reference necessary in fixing the general limit of the Tertiary in this direction, since every where throughout their range we imd these sandstones more or less overlaid by the marl, and permitting the close approach and not nnfrequently the contact of the latter with the primary. But in tracing more in detail the boundaries of the Eocene or Tertiary marl, I have deemed it not uninteresting in an economical as well as geological point of view, to present the reader with an explanation of the irregular manner in which the Tertiary strata may be expected to occur every where in the vicinity of the sandstone formation.

It will be inferred from the preceding remarks that throughout most of the Tertiary tract, south of the James river, the true line of termination for the marl is at the commencement of the primary rocks, though as formerly stated, this line is scarcely less inflected and irregular than that which marks the contact of the marl with the sandstones. As examples of this irregularity, cited formerly in a general way, I may point the reader to a locality on the Nottoway near the mouth of Harry swamp, and between 8 and 4 miles higher up than the spot in which the solitary exposure of sand- stone occurs, and to several |>oints in the neighbourhood of Hicks ford — at all of which we find granite or other primary rocks rising through the marl, thus affording exposures of the latter to the west as well as to the east of the former. Without entering into details illustrating the more important flexures of this boundary line, it will suffice for the present to indicate the general margin of the Tertiary by a straight line connecting Petersburg and Hick's ford, and thence continued to the state line.

It might be expected from the continuity of the Eocene strata, as heretofore carefully traced from the Potomac to the James river, that they would be found prolonged as a continuation of the same belt, lying at the foot of the Tertiary ridge, throughout the tract lying southward of that river. But though as already described, they shew themselves on the southern bank of the river, lying be- neath the Miocene, from a point a little below Powell's creek in Prince George, to Deep hole in Chesterfield — tlius occupying a width from east to west of not less than 15 miles — and though as far south as a line drawn a little south of Petersburg thev are still met with near the water level, yet throughout the remainder of the Tertiary tract lying in the direction of this Eocene belt, no unequiv- ocal indications of the continuation of this lower member of the

Tertiary series can be foand. At a single locality within this tract, immediately oontignous to the exposure of sandstone previously mentioned as occurring on the Nottoway above Boiling's bridge, a nodular and highly calcareous material was some years ago met with in digging a small canal. This in general aspect and composi- tion bears a striking resemblance to the calcareous concretions often found embedded in the Eocene, but from the want of fossil impressions on these masses, it would be impossible to infer with confidence to what division of the Tertiary they belong. As, how- ever, from their position where met with, they were evidently from a stratum resting on the sandstone shown at contiguous points — and as this is almost certainly in a geological sense the same with the sandstone immediately underlying the Eocene on the James river and in other parts of the state, it may be inferred as highly probable that the calcareous material in question is the representa- tive of that portion of the Tertiary in the region where it was foand.

It would appear, therefore, from all that has been smd on this sabject, that both the sandstone and the Eocene Tertiary, if pro- longed continuously towards the south, must lie at a depth that places them beyond the reach of the excavating power of the streams. Bearing in mind the interesting fact referred to under a former head, that throughout this portion of the upper Tertiary plain, the blue marl, a higher formation than the Eocene, preserves a nearly uniform level of a few feet above the water line of the rivers, it could not be expected that the latter should be reached by any of the natural excavations of the country, much less that the underlying sandstone should make its apfiearance on the river banks. It Lb moreover worthy of observation as regards the ques- tion now in view, as well as the fact of the comparatively gentle slope and shallow channels of the three principal streams intersect- ing this region, that while in common with the James, York and Rappahannock rivers, they flow from a belt of very uniform eleva- tion, immediately below the falls, and terminate their course at an unyarying level to the east, the three streams in question are com- pelled, by the direction they pursue, to traverse a much greater actual distance in making the same approach as the others to the ocean level.

ClIAPTEK 4.

Order of the Strata in this Region from the Granite up.

Having, by the descriptions above given, furnished the reader with the means of clearly marking on the map the general divisions of the Tertiary plain south of the James river, and of forming cor- rect views as regards the positions and relations of the principal gronps of strata within its limits, I proceed to a brief account of the arrangement in which those groups occur, with the view more par- ticularly of drawing attention to the subdivisions of the Miocene

Tertiary, which, wherever presented, have been f oond distingniahed bj well marked peculiaiides.

To aid the reader la acquiring clear conceptions of the order in which the several strata of this region, wherever met with, have been found to be arranged, as well as of the appearances presented at the planes of junction of the several groups or formations, indica- tive of intervening periods marked by the wearing or denuding ac- tion of water, I have constructed the following colunm or vertical section of the strata from the surface of the primary, which was antecedent to them all, to that of the soil, which is the most recent and covers them at top.

Explanation of the Geological Oolumn.

A to B — Represents the beds of sand and gravel, usually lying im- mediately below the soil, which from their oblique position and the general coarseness of the materials, indicate a de- position under the influence of strong currents. This over- spreading the region extensively, and evidently due to some general cause, is properly to be regarded as JMucium,

B to C — Horizontal beds of sand and clay, prior to the diluvium, and partially and sometimes entirely removed at the time of its deposition.

0 to D — Upper portion of the Yellow marl — a conglomerate of frag-

ments— containing in its lower parts, nearly entire, but water- worn shells.

D to £ — Lower portion of the Yellow marl — shells contained in a friable sand, and near the bottom in a tenacious clay — numerous species above, mactra modicella almost entirely beneath.

E to F — Upper Blue marl — a blue clay of fine texture — rich in mac- tra modicella — shells becoming more vaiious as we descend.

F to G — Lower Blue marl — a more sandy material — abounding both in the number and variety of its shells. G — Thin band of pebbles, separating the Miocene from the Eo- cene Tertiary,

G to H — Eocene on the James river— clays and sands usually of a greenish tinge — containing shells and their impressions — often presenting a considerable proportion of green sand and some gypsum.

H to I — Sandstone formation — deeply channelled above — before the deposition of the Eocene.

1 to K — Granite and other primary rocks, upon which the sand-

stone rests.

In this column it will be seen, that between the primary rocks and the blue marl, or lowest of the Miocene beds, both the second- ary sandstone and the Eocene are interposed, although their pres- ence in a large portion of the region south of the James river is to be regarded as only a somewhat probable inference, not a demon-

strftted fact. In this particnlar, therefore, the representation is to be looked apon as applying with nndonbted accaracy, only to that portion of the tract lying along and near the James river, at the same time that it is also a faithful picture of the whole series of formations as observed in the region north of the river.

It should further be borne in mind, that though the succession of strata, as to time and order of superposition, is faithfully indi- cated by the figure, the whole of the series of formations which it comprises are not to be looked for at any one locality. Thus, while near the western margin of the tract we may at some points be able to ifisoover the primary, the sandstone, the £ocene, and perhaps the lower portion of the Miocene, invariably resting the one upon the other, m the order in which they have been enumerated, further to the east we will meet with the remainder of the series, including the blue and yellow and fragmentary marls, the overlying horizontal days and sands, and the coarser diluvial material immediately sub- jacent to the soil, so that by connecting such observations, made at different points, through the medium of some one stratum whose established identity enaldes us to employ it as a link, we are enabled to constmct the entire column of formations in the order in which they were deposited.

Referring to the lower part of this geological column, in which the secondary sandstone is represented as resting on the granite, it is proper to remark that though in thU region no rocks more ancient than the sandstone are interposed between it and the irregular floor of primary apon which it lies, it would be inconsistent with a more extended observation of facts to infer from this that the deposition of these sandstones constituted the next important geological event, after the elevation of the granite to the position which it now occu- pies. Bo far is such an iierence from being correct, that upon a wide survey and comparison of the rocks in other parts of the state, no doubt can be entertained that all the groups of limestones, sand- stones, slates, shales, and coal seams occupying the wide region lying to the west of our Blue Ridge, are of greatly higher antiquity than the secondary sandstones here referred to, and were the geo- logical colamn complete in the tract of which I am now treating, these Appalachian and Alleghany rocks, comprising a thickness of strata of many thousand feet, would form but a portion of the for- mations which would be found interposed between the primary rocks and the secondary sandstones here Ijing as indicated in the column in immediate contact. Nor is there anything to excite surprise in the existence of a hiatus of such vast extent in the series of geological formations. Throughout a large portion of our state lying between the head of tide and the crest of the Bine Ridge, the primary rocks oocnpy the surface to the exclusion of all others, being simply cov- ered by the thin stratum of soil to wliich they have given origin by their decomposition, thus bringing into immediate juxtaposition materials appertaining to the most ancient and to modem geological productions. That this portion of the area of primary rocks, as well as that upon which the secondary sandstone in question reposes,

were not covered by deposits such as are found west of the Bine Ridge, only serves to shew that at the time in which the Appala- chian and Alleghany rocks were progressively forming beneath the bed of the wide ocean whose waters extended from our Bine Ridge over the great valley of the west, the primary surface on this side was not in a position to receive these depositions ; in other words, it was then, as the most of it is now, dry land. Along its eastern margin, however, and over some breadth of the primary in the northern portion of the tract, as extending in a direction to inter- sect our principal rivers near the head of tide, at a much later pe- riod than that of the prodnction of the formations west of the Bme Ridge, this primary surface was in a situation to receive the sedi- mentary material of which the secondary sandstones in question are composed, a material bearing evidence in its mineral nature, and the large proportion of water worn pebbles it frequently contains, as well as in the cliaracter of the organic relics by whidi in many places it is abundantly impressed, that the scene of its production was one in which marine and terrestrial agencies were combined, the margin of a broad estuary or a shallow sea.

Looking now to the group of Eocene strata resting on the surface of this sandstone, where the latter is present, we perceive in the undulating line of contact which so generally marks the junction of the two, and in the accumulation of coarse gravel near the upper limits of the sandstone, that previous to the commencement of the Eocene deposits, the subjacent rocks were deeply trenche<l, and sometimes almost entirely removed by powerful currents sweeping over their surface, bearinaway the finer materials of these rocks, and pouring into the cavities thus formed the coarse gravel and pebbles too ponderous to be removed. We see too in this rugged boundary, as thus simply depicted to the eye, and that with far more distinctness than could be communicated by mere words, how great must be the irregularity before adverted to, in the outline of the Eocene tract on the suiace of the Tertiary plain where it adjoins these sandstones, and hence we derive a strong impression of the necessity of minute individual research along the confines of the two, in deciding upon the presence or absence of the Eocene marl in neighbourhoods where it may be desired to bring it into use.

Ascending in the column to the next group of strata, we find the Miocene Tertiary separated from the Eocene by a band of pebbles or coarse sand, which, though not always present, is very generally met with in this place. These pebbles, as observed at numerous points on the Potomac, Rappahannock and Pamunkey, and less abundantly on James river, are remarkable for their black colour, and are found more or less diffused for some distance through the upper and lower beds. Here too is very commonly met with a ferru- ginous stratum, sometimes having the hardness of a rock, consisting usually of coarse sand and some pebbles, cemented by oxide of iron. But along this bounding plain, which separates the Eocene from the Miocene divisions of our Tertiary, excepting this thin band of com- paratively coarse material, we observe no evidences of physical vio-

lenee having interrened between the close of tbe Eocene and the commenoement of tbe Miocene deposits. None of that trenched and channelled confignratlon of surface remarked in the sandstone is here met with, but the smooth and unbroken level of the £ocene, washed by a gentle current jnst sufficing to develope the thin peb* bly band referred to, became the recipient of the successive strata of the overlying Miocene.

Yet though such slight marks of violent agencies are perceived in the interval between the two formations, so far as they are ex- posed in Virginia, it is interesting to observe how great a change took place in the character of the deposits when the Miooene strata began to be formed. The green sand, comparatively so abundant in some of the £ooene beds, and thence imparting to them the deep greenish colour for which they are distinguished, is scattered much more sparingly through the Miocene strata, and is often scarcely to be discerned at all, while the relics of organic life, consisting chiefly of shells, met with in such numbers in the Eocene, are with perhaps a single exception discontinued in the overlying formation, to make way for a far greater variety of species, distinct from those below. It is indeed a remarkable fact, that, one doubtful case excepted, no sbella have been met with in Virginia common to the two forma- tions, and that the inspection of a nngle shell will therefore enable the observer confidently to pronounce upon the character of the stratnm whence it was taken, whether as pertaining to the Eocene or Miocene division of the Tertiary. It has been for want of such a relic, or tbe cast of it, in the calcareous concretionary material for- merly noticed as occurring above BoUings bridge on the Nottoway, that I have been thus far unable to fomr a decided opinion as to the , presence of the Eocene in that region, and the discovery of only a solitary shell or its impression may, by removing existing doubts, furnish a motive for exploring beneath the blue marl in some por- tions of that district for beds of Eocene that at some future day may become of economical importance. Those who, misconceiving the objects the geological explorer has in view in collecting and scrutinizing with so much care the shells and other fossil relics of our marl beds and other strata, are disposed to regard his labour and attention as at best bestowed to gratify a scientific but useless curi- osity, will perceive in the facts here stated a striking illustration of the practical results which such enquiries not unfrequently unfold.

To what cause we are to ascribe this remarkable fact of the al- most entire change in the species of shellfish inhabiting the Tertiary sea, in passing from the Eocene to the Miocene formation, is a ques- tion by no means easy of solution. The seemingly almost quiet tran- sition from the one series to the other, precludes the supposition of any violent convulsion by which the former races might have been extinguished, and new conditions of the ocean and its sediments in- duced favourable to the increase of the various new species which flourished during the period when the Miocene beds were forming. Yet as such a change in the sedimentary matter is seen to have taken place along with the introduction of this new population in the bed

of the ocean, there can be no donbt that Bome important phjmeal rerolntion intervened between the Eocene and Miocene, for the dis- tinct marks of whose violence we are perhaps to look to other and distant regions in which these divisions of the Tertiary are devel- oped, and of the occarrence of some sach, geologists abroad have already become aware.

The Miocene strata thns broadly distingnished from the Tertiary beds beneath present, where entire, the three subdivisions repre- sented in the column, to wit : the blue marl, the yellow and grey marl, and horizontal beds of fine sand and clay, of which I &a& now proceed to treat in the order enumerated.

Of the Blue MdrL The strata here referred to as occupying the lowest position in the Miocene group, are distinguished by their dark bluish colour when moist, which turns to a bluish grey on drying, and by being composed of a very fine homogeneous day of a soapy feel, especially when wet Towards its lower limit, ap-

I broaching the Eocene, the texture of the clay becomes coarser and ess tenacious from tlie presence of a considerable amount of gritty sand, and near the bottom and sometimes even throughout a con- siderable part of its thickness, the sandy character is found to pre- dominate. The shelb and other fossils it contains, though genendly embedded closely together, are sometimes very thinly diaseminated through the stratum, and in almost every case are in beautiful pres- ervation, and free from the marks of violence met with in the fossils of some of the overlying beds. They are of very numerous spe- cies, associated in some cases with fragments of zoophytes resem- bling corals. This variety of species, however, is chiefly displayed in the lower portions of the strata, and is more remarkable in the exposures in the middle and western parts of the Tertiary tract than near its eastern margin. The upper portions are remarkable through- out a large extent of this region for contning a single species of shell, almost to the exclusion of the rest, and often in such great numbers as to form more than half the entire weight of the mate- rial. This beautiful little fossil (the Mactra Modicella) is a bivalve or shell consisting of two nearly equal and similar parts, of an oval figure, about three fourths of an inch in length and three fifths in breadth. Though less abundant in the lower parts of the blue marl than near the top, it is still found in considerable numbers, mingling with the other fossils, and may be regarded as characteristic of this and the next superior part of the Miocene throughout this portion of the state. In a large number of cases, these shells are found with their two valves in their natural closed position, the interstices being filled usnally with the same fine bluish clay that surrounds them. When disjoined, as well as in the state just mentioned, the valves are perfect in all their parts, retaining unbroken the mo!<t delicate processes and margins, and in general still covered with the pearly coating that naturally invests them. They are, moreover, seen to be arranged in layers or groups in the enclosing clay, and from this and the other facts Just stated, may be confidently regarded

as ocoapying the verj positions in which the saocessiye generations of animals who dwelt in them lived and died.

This great predominance of the fossil in question is lees generally observed as we trace the upper layer of bine marl towards the west. There the mactra is found to be more largely intermixed with other shells, so that the distinction of this stratum from those beneath is nearly or altogether lost.

As formerly mentioned, the blue marl is met with at a very uni- form level, of a few feet above the surface of the principal streams, in all parts of the district excepting along its southeastern margin, where it descends with an inclinaticAi towards the east and south, so as to disappear below the water.

The general direction of this line of intersection of the upper surface of the blue marl with the water plain, may be indicated by an irregularly inflected margin, commencing at Day's Point on the James river, at the locality formerly mentioned, a short distance above the mouth of Pagan creek, crossing this creek in the neigh- bourhood of Smithfield, intersecting Ghuckatuok a little below the mill, touching the Nansemond river a little below Sleepy Hole ferry, then taking a nearly meridianal direction which carries it west of the river, crossing Western branch near its mouth, and pursuing the direction of the river to the vicinity of Suffolk. Gradually bending towards the west, the line in question now strikes across to the Blackwater river, on the margin of which at a point a little below M'Glenna*8 bridge, the blue marl is seen nearly on a level with the water, and continuing in the same general course, it crosses the Nottoway a short distance below Monroe, and thence passing to the Meherrin river intersects that stream a little south of the state line and near the mouth of Flat swamp. The boundary thus indicated will of course be subject to some variation according to the fluctua- tions in the level of the water plain to which it is rerred. So that from the near parallelism of the marl and that plain, a few feet of rise or fall of the water may conceal or disclose the stratum for some distance above or below the average point of its emergence. Nor is it meant that the upper surface of toe marl is so free fh>m nndulations of level as not at various points to cause important local flexures of this line. Yet notwithstanding this irregular and somewhat mutable character of the boundary in question, it is by no means unimportant in an economical point of view, that its gen- eral course should be delineated on the map of this region — since from such an outline a more correct judgment may be formed as to the position and depth at which the blue marl may be expected to occur.

It is important further to remark, that the tract lying to the south-east or dip side of that portion of this boundary line, which extends from the vicinity of Suffolk across the Blackwater, Notto- way and Mehernn rivers, is not to be regarded as destitute of the marl, since various facts which have come to my knowledge clearly evince its existence frequently, if not generally, along the beds of those streams for some custanoe south of the state line. Nor is the

deplih at which it is thus known to exist, within a moderate dis- tance of the water boundary, so considerable as to place it beyond the reach of profitable exploration in such localities as are removed from these streams, and therefore less liable to the inconvenience of an influx of water sufficiently serious to obstruct the progress of excavation.

The general continuity of the blue marl through most of the upper Tertiary plain, has already been referred to as strongly indi- cated, if not fully established, by multiplied observations on the rivers and their tributaries throughout this region. It will there- fore be apparent that notwithstanding the absence of natural ex- posures over many tracts of the highlands of considerable extent, as well as from lociol and alluvial causes, even along the margins of the rivers themselves, this extensive region is to be regarded as very bountifully supplied with this variety of the Miocene marl — and that from the generally moderate elevation of the surface of the coun- try, few localities can be found where diggings in the ravines of from 10 to 20 feet will fail to disclose these valuable deposits.

Of the amount of calcareous matter contained in numerous va- rieties of the blue marl, the table hereafter to be given wUi convey detailed, and it is hoped, useful information.

Of the Yellow and Grey Marl, Again referring to the column, we find resting on the stratum lust described, a bed, or series of beds, characterized in general by their yellowish and greyish colour, and the larger admixture of gritty sand in the earthy part of their composition. The lowest of these beds, or that resting next above the blue marl, where exposed towards the southeastern margin of the Tertiary plain, is remarkable for its rich brownish yeUow col- our, is of a more clayey texture than those above, and contains the little shell (Mactra Modicella) before noticed, as so abundant in the blue of that district, to an equal extent. This fossil, though less predominant as we follow the light coloured marls towards the west still continues to be met with in great numbers, low down in the beds, and is rarely entirely absent in any extensive exposures of them. In general towards the middle and western parts of the tract, these yellowish and grey marls increase in thickness, present- ing a great variety and abundance of fossils, but the bright yellow band almost exclusively composed of the Mactra forming the lowest stratum, is thinner and less uniformly present than towards the east. Indeed, as will be seen from what was formerly stated in re- gard to a somewhat analogous change on the part of the blue marl as traced westward, it is evident that the line of demarcation be- tween the two is less distinctly marked in that direction than to- wards the southeastern part of the formation.

In the northern portion of the tract, the thickness of these beds as exposed at numerous localities on the tributaries of the James river, is from 15 to 20, and sometimes 25 feetthe blue marl lying beneath being often met with along the base of the same hill or cliff to the depth of several feet. In a belt situated about one third of

the whole hreadth of the tract from its eastern hotindarj, the more supertioial heds very frequently exhibit a mixture of greyish pulveru- lent or chalky marl and calcareous internal casts of shells with com- paratively few shells in an unchanged state. The same peculiarity 18 of common occurrence over a region occupying a correspondiug position in the Tertiary plain north of the James river as far as the Fotomac.

The uppermost portion of these light coloured marls is in general oharacteriied by presenting the contained fossils in a less perfect state than either the immediately subjacent beds on the blue marl, often containing along with entire specimens, a large proportion of fragments of shells. This feature is, however, but slightly displayed in the middle and most of the western parts of the Tertiary plain, but becomes very conspicuous along its eastern margin. As pre- sented in that portion of the tract, these upper beds are almost wholly composed of fragments of shells, sometimes forming a kind of shell gravel, and sometimes sufficiently minute to be considered as a calcareous sand. Each particle or piece has the worn or rounded form that attends the continued and powerful action of watet— and even the large and nearly entire shells sparingly scat- tered through the mass in many localities, have lost their sharp edges and pointed prominences, and in some cases, have been ground away until nothing but the central and thicker portions of the shell remain. Mingled in general with a small amount of gritty ferrugi- nous sand, imparting to the mass a yellowish or brownish hue, this fragmentary matter is often so firmly cemented together as to have the solidity and hardness of a rock, and indeed, in this condition is to be regarded as a Tertiary limestone. The cementing material, as might be expected, is carbonate of lime, doubtless deposited by the infiltering water, which in its progress through the upper portions of the fragmentary beds had become imbued with this substance, and in process of time deposited it in the interstices of the porous mass beneath, sometimes partially, at others entirely filling the va- cuities of the rock. This cement, as will at once be inferred, pre- sents in general a crystalline texture, and wherever it has filled up the hollow of a shell or any other cavity of considerable size, ex- hibits well marked forms of calcareous spar. As illustrating the mode in which this cementation takes place, and at the same time indicating a fact not devoid in some cases of economical interest, I may mention that wherever these fragmentary beds are exposed in considerable thickness to the inundation of tides, or to the direct access of rain, and are at the same time in the open air, as for ex- ample in the case of a or river bank, though soft or but slightly cemented at first, they are seen to grow firmer from year to year, until at length the surface, and some depth of the material, assumes the consistence of a rock. In this way blocks of the fragmentary matter which have been detached from the face of the clifif in a comparatively soft state, as in the neighbourhood of Torktown and at other places, become in time so firmly aggregated as to withstand the utmost force of the tides and waves, withoi any other loss of

parts than would occur in the case of an ordinary limestone rock. This fact of the increased hardness of the material bj exposure, has not remained unnoticed — and might perhaps, in some cases, be turned to useful account. In completing tne explanation of this cementing process, it may be well to add, that the frequent or peri- odical exposure of the moistened mass to the air, is essential to the rapid deposition of the cement — as, in the absence of the evapora- tion thus produced, the infiltering water might linger long in the interstices without depositing the carbonate of lime it had imbibed, and for the most part would pass through without leaving behind it more than a trace of the matter which it held dissolved. In a word, each of these little vacant spaces presents us, in miniature, with the same changes, under circumstances strikingly analogous, as are dis- played on so imposing a scale in the interior of some of our great lime- stone caverns, where the water that has descended through the rock, exposed to evaporation, on meeting with the air, deposits the cal- careous matter it had dissolved, in a thousand beautiful and fantaa- tic forms.

Another feature of these fragmentary beds, plainly indicating an agitated state of the waters during their deposition, is the oblique and varying directions in which the layers of fraffments are laid one upon the other, while the stratum, viewed as a whole, is nearly hori- zontal in its position. Its component parts are arranged in their parallel bands, frequently at a high angle to the bounding surfaces of the bed, and by a similar cause, those of a higher or a lower bed are made to present an inclination in the opposite or some different direction, as if successive currents moving towards different points had dropped these fragments upon sloping surfaces, and thus adding layer upon layer, all preserving the original inclination, had gradu- ally completed the stratum to its upper level.

As already stated, these fragmentary beds are not confined to the eastern margin of the plain, but are also found, though in far less extent, at various points approaching its western boundary.

Though frequently found, as indicated in the column, with a stratum of yellowish marl between them and tiie blue, they are sometimes seen resting on that stratum, in a line whose undulating and broken contour plainly indicates the violence that accompanied their formation, and conveyance to the spots in which they are ac- cumulated. In fact, these fragmentary beds can only be regarded as the worn and broken remnants of the lighter coloured marls over- lying the blue, sometimes usurping the place of the original strata which have been washed away to furnish the materials of which they are composed, and sometimes occupying the place of the upper- most of these strata, and resting on a layer which had escaped the destroying actions experienced by those above.

As might be inferred from its being of later formation than either of the other beds, and therefore higher in position in the se- ries, as exhibited in the column, this marl is the nrst that shows it- self as we ascend the James river. Spread out extensively in Eliza- beth City county on the opposite side of the river, its most easterly

ezpoenre on the Bonth Bide is at the month of Bennetts creek, a trioatary of Nansemond riyer. Here it is seen nearly on a level irith the water, but ascending this river, and therefore going slightly west, its southeastward dip causes it to rise to a greater and greater height, until the yellow marl appears beneath it, and as it still con- tinues to rise, the blue comes into view beneath the yellow. From this, the line of its first exposure, it spreads out towards the west and north, forming the upper stratum in most of the exposures near the James river between Nansemond river and Pagan creek, displaying itself on and near the surface in the vicinity of Smithfield, and terminating at Day's Point As measured on and near the James river, therefore, its breadth would include the distance be- tween the meridian's passing through Bennett's creek, and the last exposure of it at Day's Point, being about 9 miles. But as we trace it towards the south, we find it rapidly contracting, so that at Suffolk only a narrow band of it remains. .

Throughout the middle and nearly all the western portions of the Tertiary plain, as already stated, the upper beds, though often containing fragments of shells, present no accumulations of frag- mentary matter sucli as have been described. Nor is the broken condition of the fossils there met with unaccompanied by those evi- dences of long continued trituration in water, and of transportation by currents, evinced in the worn and rounded forms and oblique depoeition of the strata above described. They may therefore be reasonably referred to transient causes, while the others would seem to be more naturally explained by the tides and currents of the an- cient coast line, formerly adverted to as adjoining the eastern mar- gin of the higher plain.

Unlike the lower or bine marl, these yellow or light coloured marls are not found to be continuously or even very generally ex- panded beneath the Tertiary plain. Along the James river and for many miles towards the south, they are of very frequent occurrence ; but as we proceed still further south, they present themselves more rarely, and for the most part in places remarkable for their elevation above the general level of the country. So uniform is this connec- tion of the beds in question with the more elevated ground about the middle of the tract, that few instances exist in which they are met with under other circumstances.

Thus beneath the high grounds formerly referred to as running from Nottoway swamp parcdlel to the Blackwater river, and along the river wherever the banks attain unusual height, the yellow marls are found rising in some cases to an elevation of 80 feet above the stream, while the blue stratum is seen skirting the base of the cliff in a narrow band, or is met with at various points beneath the highlands removed from the river. In the similar tract of elevated ground lying near and west of the Nottoway river, and extending from the neighbourhood of Three creek across Racoon and Hunting Quarter creeks, these yellow and light coloured marls are largely exposed, presenting a depth sometimes exceeding 20 feet, and rest- ing on the blue stratum near the water level.

Though thus generallj confined to the higher grounds, these yellow and light oolonred marls are not continnoasljr spread oat even within these narrow areas, bnt appear to exist in irregular patches, lying nearly at the same level as to their nnder surfiace, though presenting great irregularity of thickness even in contigaoos exposures, and often entirely wanting in one locality, while at some other place in the same neighbourhood they are met with largely developed.

This absence of the marls in question from so large a portion of the Tertiary plain, together with their occurrence in patches, and associated with the higher levels of the country, would seem to admit of a natural explanation in the powerful removing or denud- ing action of the water as it rapidly poured off from the surface in one broad tide at the time of the emergence of this plain from the bed of the sea. That a deep channelling of the surface, such as a retreating mass of waters might in most cases be expected to pro- duce, is not now exhibited over the middle portions of this tract, would seem to have resulted from the uniform and gentle inclina- tion of the plain towards the southeast, and from the filling up of the irregularities produced by the first rush of the waters by the sand and other sedimentary materials spread over the surface as the mass and energy of the water diminished. It is obvious that such an action as here supposed would give a fragmentary charac- ter to the upper stratum of the marl in general, and would accumu- late the broken shells in heavy beds towards the eastern margin of the plain, conditions, both of which we have seen really to exist. The same agency too would account for the presence along that margin of the coarse gravel which has been described as overlying the fragmentary beds, while the constant wearing action of the waves along the beach would give a rounded figure to the frag- ments of shell, ere they had Mvlj become consolidated by the cementing process formerly described.

But whatever be the explanation of this discontinuous occur- rence of the light coloured marls, the fact of their being placed at a nearly uniform level, is not without importance, for though we cannot reasonably entertain the confidence of meeting with them at any point because of their known existence at some other in the neighbourhood, we may feel almost assured that where they do occur, the blue stratum lies not far beneath, and where they are absent, their general level in the neighbourhood will furnish a useful guide as to the depth at which this lower marl may be expected to be reached.

The line of boundary between the blue and upper marls, as in- dicated in the figure, is often undulating, and in some points pre- sents such strikingly abrupt irregularities, as lead to the presumption that some important agitation of the waters intervened locally, if not generally, between the deposition of the two. At some locali- ties chiefly near the eastern margin of the plain, fragments of the blue are met with in the yellow, and what is still more remarkable, fragments of the yellow in the underlying blue, as if soon after the

2T5

commenoement of tbe yellow marls, some Tiolecce bad operated to iDtermix tbe tvro. At all events, it would seem obvious that during the deposition of tbe yellow and light coloured marls, a different condition of tbe waters roust have prevailed, since tbe earthy mat- ters mingled with tbe shells are so much more largely imbued with ferruginous matter, and contain comparatively little of the material of organic origin, which occasions tbe dark oolonr of tbe other.

In many portions of the tract, horizontal strata of sands and clays are seen overlyiug the beds of marl. When tbe surface of the marl is uniform, tbe lowest of these beds presents the appear- ance of having been quietly and slowly deposited upon it, but where indications of violence are met with in the top of tbe marl, the materials for some distance above are more or less obliquely strati- fied, and seem to have been poured in with some force. The upper of these earthy strata are usually arranged in level layers, and would seem to have been slowly accumulated in still water, and judging from tbe entire absence of marine impressions in them and tbe occasional occurrence of decayed vegetable matter, may be supposed to have been deposited during the inundations produced by tbe rivers, which in the then lower level of the plain must have been both frequent and extensive. Perhaps too in many local cases, tbe extensive shallow lakes or morasses that must have then existed, contributed to the formation of some of the higher of these beds.

Covering these horizontal strata composed of fine materials, we Tery frequently meet with others in which coarse sand and gravel are predominant, containing occasionally a pebble of 2 or 8 inches in diameter. These in the middle portion of the tract are chiefly met at the highest pointa — towards the west, they are more ex- tensively spread out. As indicated in the column, they often occur, filling deep trenches or cavities in inferior earthy strata just de- scribed, and sometimes even penetrating below tbe upper surface of tbe marl. Tbe coarseness of their parts and tbe oblique and var3ring inclination of the layers composing them, indicate the vio- lence and suddenness with which they were deposited. In a word, they are tbe diluTium of this region, and refer themselves to the same general cause which, after the completion of our formations, spread similar materials over nearly every port of tbe surface of the Atlantic states between tbe mountains and the ocean.

I have thus endeavoured to present the reader with a brief sketch of the limits and subdivisions of our Tertiary formation, as spread out in tbe region south of tbe James river, and referring as I have done at each important step to the physical causes which would ap- pear to have been concerned in the production of the various strata, whether of marl or earth and gravel, I have been influenced by the hope that the picture I was drawing would in this way be rendered not only more interesting, but more intelligible and useful. May I not further hope, that from the broader views thus exhibited, indi- vidual curiosity will be awakened to a more attentive examination of tbe deposits of this region, and that thus some additional practi- cal good may be secured.

J

Ghaptkb 5.

Illttstratiom of the Column exhiMting tho order of the Strata,

As exemplifying the application of a portion of the column, I will now refer the reader to the series of strata exhibited at a few localities, requesting however that he will bear in mind that similar details have been collected at nearly every important ex- posure within the district, of which a full account will be given along with other interesting matters connected with this region in the final report.

1. South shore of the James river in the neighbourhood of Days Point and BurwelPs bay.

From the spot a little above the mouth of Pagan creek, where the marl is first seen to emerge from the level of the beach, nearly continuous exposures of both the blue and yellow beds are met with for several miles, the chief interruption taking place at a marshy part of the shore, a short difltance from the first appearance of the marl. Along this tract the blue stratum presents great undulations in height, attaining in some cases a level of 20 feet above the base of the cliff, but at all times overlaid hy the light yellowish marU This latter is often fragmentary and cemented at the top, above which are layers of clay, varying from a fine and tenadons to a sandy and loose texture. Particles of green sand are disseminated through the marls, as well as the overlying sandy days.

2. In the vicinity of Smithfield on Pagan creek, as wdl as along its tributaries, Smithfield creek and Cypress creek, the light coloured and the fragmentary beds are largely exposed, the latter constitut- ing the rocks on the lower shore of Smithfield creek, and being en- countered in the wells of the village and its neighbourhood. Some distance up the two tributary creeks, as at Makefree on Smithfield, and Scott's mill on Cypress creek, the hlue marl is met with heneaik the yellow. Similar remarks will apply to Chuckatuck and Nan- semond river, the fragmentary marl making its appearance at the lowest or most easterly localities, and as we ascend and bend west- wards, the yellow appearing beneath, and eventually the hlue com- ing into view a little above the water line. These appearances are of course irregularly presented in consequence of original undula- tions of the stratri, as well as the broken or trenched condition of the surface throughout this portion of the Tertiary plain. In the vicinity of Suffolk and towards the west, the yellow and blue maris are observed at numerous points in the same relative positions, and abounding in the Maotra Modicella in beautiful preservation. The fragmentary layer disappears a short distance towards the west of the village, and the overlying beds consist of fine sands and clays containing very few pebbles and horizontally stratified.

8. On the Black water from M'Clenna's bridge northwards both varieties of marl are very frequently met with in the river banka and the contiguous ravines, and though less frequently exposed along the upper portion of the stream, as it penetrates Prince George

Ht'un-"Prs nr.a-

and divides Snsaex from Surrj coimtj, are still disclosed wherever natoral sections of safficient depth exist.

Just below where Bark*s swamp empties into Black water, a high hill, which is part of the ridge formerly spoken of, boands the river on the Soathampton side, presenting at some points an elevation bat little short of 50 feet, of wltich more than thirty are made up of the two marls. Here, wherever the face of the bank is open to inspec- tion, the underlying blue stratum is fomid rising a few feet above the river level. It contains a variety of shells, the little Mactra be* ing the most abundant. Above are Uie beds of yellow and brotenisk marle the lower being a bright yeUow clay fall of this Kactra, the npper a yellowish brown sandy clay, containing the Mactra largely mingled with other shells. The top of the marl is nndu- ladng, and covered with layers of sand and clay, generally of fine textare.

4. On the Nottoway, from a little below Monroe to the neighbonr- hood of Carey's bridge, the blae marl is exposed at varioas points, bat rarely if ever accompanied by the yellow. As already men- tioned, it is found still lower down the stream, to some distance be- yond the state line, beneath the water level in the bed of the river. Above Three creek, where the river adjoins the high groands for- merly referred to, both varieties of marl are seen.

On the estate of colonel Blow, about miles below Peter's bridge, these hills bordering the river present an elevation of about 50 feet, of which 25 consist of the yellow and light coloored marls. The npper portion of the marl is ferruoinotu and tenacious, and rich in the little Mactra, contuning also concretionary nodules marked with impressions of this shell, and occasionally including small crystals of selenite or gypsum. Beneath this the marl is of a greenish grey eolour, derived evidently from the numerous grains of green sand (tispersed through the mass. These, with a rather coar white or yellowish sand, constitute the chief material in which the shells are enclosed. A great variety of species is here presented, shewing a more perfect state of preservation as we approach the level of the bltie marl, which at low water is visible along the mar- gin of the stream. The beds capping the marl are fine pipe clays and sands.

5. On the Meherrin, a little inland, about one mile south of the state line near Flat swamp, both varieties of marl, abounding in the Mactra, are met with on the estate of Mr. Wood, but along the river higher up, the blue marl is almost the only one exposed until we pass Dupre's bridge. About 8 miles above this point, on the estate of Mr. Ivy, the river presents a section of about 20 feet, the upper ye or six of which consists of light indurated sandy clay, below this a compact white sand, from 4 to 5 feet thick, containing near the bottom numerous im])ressions of shells — below this a very hard ferruginous layer, 2 to 8 feet thick, filled with similar impressions — and beneath this a yeUovo sandy clay abounding in the little Mactra and a small tnrreted shell, both in a very soft condition. Lowest of all is a bluM mixture of sand and clay including a great variety of

CnAPTSB 5.

IllustrationB of the Column exhibiting the order of the Strata,

As ezemplifjnng the application of a portion of the colamn, I will now refer the reader to the series of strata exhibited at a few localities, requesting however that he will bear in mind that similar details have been collected at nearly every important ex- posure within the district, of which a full account will be given along with other interesting matters connected with this region in the final report.

1. Soutn shore of the James river in the neighbourhood of Days Point and BurwelPs bay.

From the spot a little above the mouth of Pagan creek, where the marl is first peen to emerge from the level of the beach, nearly continuous exposures of both the blue and yellow beds are met with for several miles, the chief interruption taking place at a marshy part of the shore, a short difltance from the first appearance of the marl. Along this tract the blue etratum presents great undulations in height, attaining in some cases a level of 20 feet above the base of the cliff, but at all times overlaid by the light yellowith marl. This latter is often fragmentary, and cemented at the top, above which are layers of clay, varying from a fine and tenacious to a sandy and loose texture. Particles of green sand are disseminated through the marls, as well as the overlying sandy clays.

2. In the vicinity of Smithfield on Pagan creek, as well as along its tributaries, Snfithfield creek and Cypress creek, the light coloured and the fragmentary beds are largely exposed, the latter constitut- ing the rocks on the lower shore of Smifield creek, and being en- countered in the wells of the village and its neighbourhood. Some j distance up the two tributary creeks, as at Makefree on Smithfield, and Scotts mill on Cypress creek, the blue marl is met with beneath the yellow. Similar remarks will apply to Chuokatuck and Nan- semond river, the fragmentary marl making its appearance at the lowest or most easterly localities, and as we ascena and bend west- wards, the yellow appearing beneath, and eventually the blue com- j ing into view a little above the water line. These appearances are i of course irregularly presented in consequence of original undula- tions of the strata, as well as the broken or trenched condition of I the surface throughout this portion of the Tertiary plain. In the vicinity of Sufifolk and towards the west, the yellow and blue marls are observed at numerous points in the same relative positions, and abounding in the Mactra Modicella in beautiful preservation. The fragmentary layer disappears a short distance towards the west of the village, and the overlving beds consist of fine sands and clays containing very few pebbles and horizontally stratified.

8. On the Black water from M'Clennas bridge northwards both varieties of marl are very frequently met with in the river banks and the contiguous ravines, and though leas frequently exposed along the upper portion of the stream, as it penetrates Prince George

ICe':.ffP''i'.nr<)a f-

and divides Snssex from Bnrrj oonntj, are still disclosed wherever natural sections of safficient depth exist.

Jast below where Bark's swamp empties into Blackwater, a high hill, which is part of the ridge formerly spoken of, bounds the river on tlie Soathampton side, presenting at some points an elevation but little short of 50 feet, of wldch more than thirty are made up of the two marls. Here, wherever the face of the bank is open to inspec- tion, the underlying blus stratum is found rising a few feet above the river level. It contains a variety of sheUs, the little Mactra be- ing the most abundant. Above are Uie beds of yellow and hrownieh marlsy the lower being a bright yellow clay fuU of this Mactra, the upper a yellowish brown sandy clay, containing the Kactra largely mingled with other shells. The top of the marl is undu- lating, and covered with layers of sand and clay, generally of fine texture.

4. On the Nottoway, from a little below Monroe to the neighbour- hood of Carey's bridge, the blue marl is exposed at various points, but rarely if ever accompanied by the yellow. As already men- tioned, it is found still lower down the stream, to some distance be- yond the state line, beneath the water level in the bed of the river. Above Three creek, where the river adjoins the high grounds for- merly referred to, both varieties of marl are seen.

On the estate of colonel Blow, about H miles below Peter's bridge, these hills bordering the river present an elevation of abont 50 feet, of which 25 consist of the yellow and light coloured marls. The upper portion of the marl is ferruginotu and tenacious, and rich in the little Mactra, containing also concretionary nodules marked with impressions of this shell, and occasionally including small crjrstals of selenite or gypsum. Beneath this the marl is of a greenUh grey colour derived evidently from the numerous grains of green sand dispersed through the mass. These, with a rather coar white or yellowish sand, constitute the chief material in which the shells are enclosed. A great variety of species is here presented, shewing a more perfect state of preservation as we approach the level of the blue marl, which at low water is visible along the mar- gin of the stream. The beds capping the marl are fine pipe clays and sands.

5. On the Meherrin, a little inland, about one mile south of the state line near Flat swamp, both varieties of marl, abounding in the Mactra, are met with on the estate of Mr. Wood, but along the river higher up, the blue marl is almost the only one exposed until we pass Dnpre's bridge. Abont 8 miles above this point, on the estate of Mr. Ivy, the river presents a section of about 20 feet, the upper five or six of which consists of light indurated sandy clay, below this a compact white sand, from 4 to 5 feet thick, containing near the bottom numerous impressions of shells-below this a very hard ferruginous layer, 2 to 8 feet thick, filled with similar impressions — and beneath this a yeUow sandy clay abounding in the little Mactra and a small turreted shell, both in a very soft condition. Lowest of all is a bluish mixture of sand and day including a great variety of

shells. This contiimes to the water's edge and forms the bed of the river.

The localities above enumerated and briefly described have been selected remote from each other, and lying npon the principal streams, with the view of illustrating the statements formerly made as regards the continuity of the blue marl, as well as of shew- ing the true order in which the various beds are arranged, wherever the localities are of sufficient elevation to present a section of the whole of the Miocene strata. The reader will at once perceive the unvarying order of their position as above described, and its corre- spondence with that represented in the column, and is desired to bear in mind that no violation of that order has yet been observed in any of the numerous localities that have been minutely exam- ined. He should also remember that while the blue marl, expand- ing in thickness as it spreads west and north, becomes gradually mingled with the grey overlying marls, the distmctly yellow marl is rarely seen, having, as formerly indicated, been probably swept away, excepting in those higher positions where it is now almc exclusively to be found.

Chaptsb 6.

Of the cauHB of the peculiar CoIouvm of the Blue and Yellow Marls.

As will readily occur to the reader, the yellow marls owe their hue to an intermixture of oxide of iron, which even in the small proportion in which it is mingled with the other matters of these oeds, is capable of imparting a bright ochreons yellow or a deep brownish tinge. The source of this ferruginous matter so generally present in the upper marl beds, as well as in the clays and sands which rest immediately upon them in numerous places, is for the njost part to be sought for in a peculiar condition of the waters at the time in which these beds were forming, and not in the penetra- tion of ferruginous matter from the overlying diluvium. Such a condition would naturally result from the extensive prevalence of a turbid state of the sea, like that so often witnessed in the waters of the James river, when heavy rains have conveyed into them the red earthy matter met with so extensively on the surface of that por- tion of the state lying between the head of tide and the Blue Ridge.

It is true that some of the strata lying near the surface, would seem to have derived their brownish ferruginous stain from the in- filtration of water charged with a particular compound of iron from above. But in such cases it will be remarked, that the shells have been either in part or totally removed, leaving in the stratum, once rich in calcareous matter, little more than the mere prints or im- pressions of the fossils ; and tliis condition, not nnfrequently ob- served in the Tertiary district of which I am treating, is as often remarked of the blue as the light coloured marls, being in a great measure dependent upon the proximity of the bed of fossils to the overlying acid and astringent clays and sands. But the bright yel- low and ferruginous marls now referred to as forming the higher

beds in tbe series, retain their fossils in as perfect a condition as the bine marls beneath them, and have evidently not been subjected to the dissolving action of infilterlng copperas (sulphate of iron), but have received the ferrnginons colouring matter, in the state of a sediment, from the waters in which the strata were forming.

The blue marls differ from the former chiefly in containing little or no iron, and in being impregnated to a greater extent with matter of organic, probably animal origin. Both varieties exhale by heat- ing, a perceptible amount of carbonate of ammonia — and the blue becomes of a dark, nearly black, tinge, from the crnantity of carbon- aceous matter (charcoal) which is developed by the imperfect com* bustion. The same change though in a much less striking degree takes place also in the yellow. 1 his greater prevalence of what ap- pears for the most part to consist of animal matter, seems to be naturally explained by the deeper position of those strata — since in virtue of such a position they would receive by infiltration from the upper beds a portion of the animal matter derived from the decay- ing shellfish of those beds, which would be added to that originating from like decompositions in the blue marl itself — while the yellow marls thus robbed of a portion of this ingredient, would be without the means of replacing it from above.

Whatever be the cause of the difference in question, it is far from improbable, that if the fact of its existence prove as general as I have reason to believe it is, a sufficient explanation will be thereby fiimished of the superior efiicaoy of the blue marls as ma- nures, of which a very general impression is prevalent throughout the southern portion of this tract. It is true the amount of organic matter present in any of them is very small, but it should be borne in mind that in tbe application of stable manures to fields, the quan- tity per cent, added to the soil is very inconsiderable. Moreover the carbonate of ammonia, one of the exhalations from the manure heap, is an agent of considerable power, and this, though in very minute quantity, is certainly present in the marls in question, and capable of being removed by water as well as given off at a gentle heat.

Chapteb 7.

Amount of Carbonate of Lime in the Maris,

In looking over the following table of the per centage of carbon- ate of lime contained in the various specimens of marl enumerated, it will be seen that while great differences prevail among them as to tbe amount of this ingredient, in no instance is its quantity so small as to furnish a reason for omitting to apply the marl, on the plea of its probable inefficacy, as a manure. In comparing tbe value of these materials, as regards their more immediate effects, all who have had experience in their application to agriculture, are aware that the poorer marls are often productive of as much or even greater benefit than the rich, when through tbe softer texture of the shelly

shells. This contiimes to the waters edge and forms the bed of the river.

The localities above ennmerated and briefly described hare been selected remote from each other, and lying apon the principal streams, with the view of illustrating the statements formerly made as regards the oontinaity of the blue marl, as well as of shew- ing the true order in which the yarious beds are arranged, wherever the localities are of sufficient elevation to present a section of the whole of the Miocene strata. The reader will at once perceive tiie unvarying order of their position as above described, and its corre- spondence with that represented in the column, and is desired to bear in mind that no violation of that order has yet been observed in any of the numerous localities that have been minutely exam- ined. He should also remember that while the blue marl, expand- ing in thickness as it spreads west and north, becomes gradually mingled with the grey overlying marls, the distinctly yellow marl is rarely seen, having, as formerly indicated, been probably swept away, excepting in those higher positions where it is now almost exclusively to be found.

Chapter 6.

Of the causes of the peculiar Colours of the Blue and Tellou) Marls,

As will readily occur to the reader, the yellow marls owe their hue to an intermixture of oxide of iron, which even in the small proportion in which it is mingled with the other matters of these beds, is capable of imparting a bright ochreous yellow or a deep brownish tinge. The source of this ferruginous matter so generally present in the upper marl beds, as well as in the clays and sands which rest immediately upon them in numerous places, is for the njost part to be sought for in a peculiar condition of the waters at the time in which these beds were forming, and not in the penetra- tion of ferruginous matter from the overlying diluvium. Such a condition would naturally result from the extensive prevalence of a turbid state of the sea, like that so often witnessed in the waters of the James river, when heavy rains have conveyed into them the red earthy matter met with so extensively on the surface of that por- tion of the state lying between the head of tide and the Blue Ridge.

It is true that some of the strata lying near the surface, would seem to have derived their brownish ferruginous stain from the in- flltration of water charged with a particular compound of iron from above. But in such cases it will be remarked, that the shells have been eitlier in part or totally removed, leaving in the stratum, once rich in calcareous matter, little more than the mere prints or im- pressions of the fossils ; and this condition, not unfi*equently ob- served in the Tertiary district of which I am treating, is as often remarked of the blue as the light coloured marls, being in a great measure dependent upon the proximity of the bed of fossils to the overlying acid and astringent clays and sands. But the bright yel- low and ferruginous marls now referred to as forming the higher

beds in the series, retain their fossils in as perfect a condition as the blue marls beneath them, and have evidently not been subjected to the dissolving action of infiltering copperas (sulphate of iron), bat have received the ferraginons coloaring matter, in the state of a sediment, from the waters in which the strata were forming.

The bine marls differ from the former chiefly in containing little or no iron, and in being impregnated to a greater extent with matter of organic, probably animal origin. Both varieties exhale by heat- ing, a perceptible amount of carbonate of ammonia — and the blue becomes of a dark, nearly black, tinge, from the cruantity of carbon- aceous matter (charcoal) which is developed by the imperfect com- bustion. The same change though in a much less striking degree takes place also in the yellow. This greater prevalence of what ap- pears for the most part to consist of animal matter, seems to be naturally explained by the deeper position of those strata — since in virtue of such a position they would receive by infiltration from the upper beds a portion of the animal matter derived from the decay- ing shellfish of those beds, which would be added to that originating from like decompositions in the blue marl itself — while the yellow marls thus robbed of a portion of this ingredient, would be without the means of replacing it from above.

Whatever be the cause of the difference in question, it is far from improbable, that if the fact of its existence prove as general as I have reason to believe it is, a sufiScient explanation will be thereby furnished of the superior efiicacy of the blue marls as ma- nures, of which a very general impression is prevalent throughout the southern portion of this tract. It is true the amount of organic matter present in any of them is very small, but it should be borne in mind that in the application of stable manures to fields, the quan- tity per cent, added to the soil is very inconsiderable. Moreover the carbonate of ammonia, one of the exhalations from the manure heap, is an agent of considerable power, and this, though in very minute quantity, is certainly present in the marls in question, and capable of being removed by water as well as given off at a gentle heat.

Chapteb 7.

Amount of Carbonate of Lime in the MarU.

In looking over the following table of the per centage of carbon- ate of lime contained in the various specimens of marl enumerated, it will be seen that while great differences prevail among them as to the amount of this ingredient, in no instance is its quantity so small as to furnish a reason for omitting to apply the marl, on the plea of its probable inefficacy, as a manure, lu comparing the value of these materials, as regards their more immediate effects, all who have had experience in their application to agriculture, are aware that the poorer marls are often productive of as much or even greater benefit than the rich, when through the softer texture of the shelly

matter they contain, tbey are more easUy spread with nniformitj upon the land.

The rocky marls, some of which are as rich in carbonate of lime as ordinary limestone, are nevertheless bat little likely to produce a striking improvement when first applied, tbongh as they are slowly resolved into smaller fragments, they will scarcely fail to give rise to a permanent and increasing amelioration of the soil. Fortunately for a large portion of this district, the blue marl, which from its more general distribution, will be chiefly looked to as a means of agricultural improvement, besides containing in most localities a very adequate amount of calcareous matter, and having perhaps other advantages already glanced at, includes comparatively few shells of large size, and of a texture to resist for any considerable time, the action of the atmosphere and rain and frost. The little Mactra so often mentioned before as largely predominant in the upper and more accessible beds of this marl, reaoily falling to pieces and mingling in fine fragments with the soil, seems particularly sdapted for prompt and efScient operation on the land. So also the Ohama, a small rugged shell, conspicuous in the greyish and greenish marls, towards the middle and western portions of the tract, especially in the neighbourhood of the James river, though more resisting than the Mactra, is already sufSciently small to admit of an even distribu- tion on the surfiEuse, and cannot long withstand the decomposing agencies to which it is exposed.

In reference to the subjoined table, it is scarcely necessary to add, that as well as could be jjudged, tlie specimens selected for analysis in these and previooB instances, have been taken as pre- senting the average character of the bed, wherever extensively ex- posed. Including the sixty Miocene marls reported on at a former time, the whole number of these marls from the south side of the James river, which have been thus far analysed, amounts to no less than one hundred and ten, and the entire number thus examined, since the commencement of the survey, some of them not yet re- ported on to the public, is upwards of 250. While indulging no ex- aggerated ideas of the importance of these numerous results, but regarding them as occasionally furnishing a guide in the application of our marls, I may be indulged in saying what I am confident would be found true, that so large a body of chemical results of this kind, has not, up to tliis time, been presented to the agriculturists of any other quarter of the globe. And in conclusion, I would add, that a large additional series of such analyses are yet to be made, embracing marls from numerous localities in other parts of our Tertiary region, as well as some remaining points in the district south of the James river. Towards this object, as it is impossible, either in person or through my assistants, to visit every marl bed in the state, I would ask such persons as are interested in these results, to reserve specimens of their marls, which if not obtained in the course of further explorations, will reach me by being transmitted to Richmond, to the care of the Board of public works.

SECTION III. SOUrmSBH DISTRICT EAST OF TITS BLUE BJDGK

Ghapteb 1.

Plan of JExploration — General Geology,

The explorations in thia region have been carried on by making nnmerouB local as well as many prolonged sections, traversing each ooonty nsnally in several lines transverse to the range of the rocks, and by tracing the more important strata longitudinally between these sections. As yet, these minute enquiries have not been car- ried in an easterly direction beyond a line drawn about midway through Halifax, Charlotte, Prince Edward and Cumberland coun- ties, although several exploratory sections have been carried to the eastern verge of this district where it adjoins the Tertiary marl. In conducting these enquiries, particular attention has been given to the numerous bands of oblong patches of limestone presented at various points, as well as to the beds of rock of a different descrip- tion, suited for architectural or other uses. The deposits of iron ore, some of which are of important extent and favourably situated for manufacturing purposes, together with the veins or beds contain- ing other minerals of economical or scientiiio value, have also been subjects of very special examination. A minute investigation has also been made of the rocks constituting the tracts. In addition to these points of more particular research, minute enquiry has been directed to the interesting tracts in Pittsylvania, Halifax, Campbell, Prince Edward, Cumberland, Buckingham and Nelson counties, occupied by a series of strata consisting chiefly of red diales and sandstones, hereafter to be described under the title of the middle secondary formation, determining as accurately as possible the boundaries of these tracts with a view to their representation on the map, carefully examining from point to point the strata of which they are com- posed, and more especially scrutinizing the indications witnessed at numerous localities, from which have been derived the hope of find- ing valuable deposits of coal in the rocks of this formation.

Of the large mass of information thus collected, a brief outline will be now presented, embracing such details and general results as may serve to illustrate the progress of our operations in the dis- trict under consideration, and as an accompaniment to this sketch likely to be useful to such as are unacquainted with the terms by which the numerous varieties of rocks and minerals met with in this region are properly to be designated, I will in the first place intro- duce a description as familiar as possible of the more important of these varieties, according to the names by which in scientific lan- guage they are respectively known. In entering on this description, it may not be inappropriate to observe, as bearing upon a common misconception as to the utility of these learned technicalities, as they are sometimes called, that of the necessity of some such special des- ignation for each peculiar mineral, mixture or compound, no doubt

form the prindpal constituents of rocks taken in the aggregate, and of the two, silex is the more ahtmdant. The same is tme of soils in general, which in regard to their mineral nature, are but decom- posed or'pulyerized rock.

2. Felbpab. An unmixed mineral, verj abundant in rocks. It is white, yellowish, flesh coloured, and of other hues, rarelj trans- parent, and when so, called glawy feUpar, Its crystals form the opaque white portion of common granite, which is often seen to decompose by exposure to the weather into a white smooth powder, resembling the finest chalk. This powder constitutes porcelain elay and is found very abundantly in the neighbourhood of decomposing felspathic rocks. Numerous localities of this clay are met with in the primary region, among which may be mentioned a belt passing through Prince Edward and Cumberland counties, a little east of their court-houses.

As might be expected, wherever this mineral in a deoomposinff state abounds, a tenacious clayey soil is the result. The principcd ingredients of common Felspar are silex, alumina and potash — but there is a variety called Albite from its peculiarly white colour, in which soda takes the place of the potash. This is the more liable of the two to decomposition. While undergoing this change, they lose their potash and soda, which are carried off by the pervading moist- ure. Owing to the presence of these alkalies, Felspar is capable of being fused into a kind of glass. Hence the impropriety of select- ing for hearth-stones for furnaces, as has been done in some in- stances in this state, granite or any other rock in which tbere is Felspar. The residuary clays from which the potash and soda have been removed, may be used in their crude state for the manufacture oifire-hieh.

8. Mica.. An unmixed mineral having a shining silvery surface, and capable of being split into very thin elastic leaves or scales. In common with some other minerals resembling it, it is vulgarly called Isinglass. It constitutes the shining part of granite, and when by the falling to pieces of the rock, caused by the decomposition of the Felspar, it mixes with the earth, its innumerable glistening scales are the mark of what is called an mnglam Mil. It is of various aspects, transparent, green, black, silvery, golden. When perfect, the thin scales are regular six sided figures. It is one of the most indestructible of minerals by ordinary natural agencies, being found in the sands of the Tertiary formation, though to have reached such a position it must in many instances have passed through the suc- cessive stages of the secondary formation after its first separation from the primary rocks of which it was originally a part. The principal ingredients of Mica, are silex, alumina, potash and oxide of iron (or iron rust). In many rocks the scales of this mineral are arranged in layers, and thus impart to the mass the property of being readily split into slabs in the direction of these layers. Many superior varieties of building stone contain much Mica.

4. TALa An unmixed mineral, bearing a strong resemblance to Mica, bat distingoished from it by its want of elasticity when divided into thin layers, by its being readily scraped with the nail, and by the smooth and soapy feel of its suifaoe — from which last property rocka containing mach of it are not nnfrequently called soap stone. Its most nsnal colonrs are varions shades of green. In composition it greatly differs from Mica, consisting chiefly of silez and magnesia. This mineral is present in many of the rocks of our primary region, partioalarly saoh as have a slaty character. It is fonnd in crystal- line plates of a bright green colour, at the Folly in Amherst county, and in other localities.

5. HoRiTBLEKDB. An unmizcd mineral of a dark green or black colour. Fonnd in small slender crystals closely compacted together, or in crystals of a more granular form. It is the ingredient that gives the dark colour to many of the primary rocks, and to trap ; and being much denser than either of the preceding minerals, im- parts to these rocks their superior weight. When decomposed, it usually forms a soil of a deep red colour, always remarkably produc- tive. The black sand so common in the neighbourhood of Horn- blende rocks, is in part composed of the unchanged granules of this mineral. Bornblende is composed chiefly of silez, alumina, lime, magnesia and ozide of iron. To its lime, which sometimes amounts to 14 per cent., and in some measure also to its magnesia, may no doubt be ascribed the peculiar fertility of the soils it produces. From its weight and greenish colour, as well as from the occasional occurrence of a little copper with it, Hornblende is often mistaken for an ore of that metaL

6. Epidotb. An unmized mineral, sometimes crystallized in slender diverging crystals, sometimes in grains of various shades of green and yellow, but as found with us usually of a light green, harder, and a little more ponderous than Hornblende. Like that rock, when decomposed, it forms a soil of a deep red colour, and, if anv thing, more fertile. The red lands of Albemarle, and parts of Nelson and Campbell counties are due to this rock and Horn- blende, but chiefly to this. It contains the same ingredients as Hornblende, wanting the magnesia, and having more lime and alu- mina, the former sometimes amounting to 24 per cent. The red colour of the soil, derived from both these minerals, is due to the large proportion of ozide of iron they contain, sometimes amount- ing to 80 per cent.

This mineral forms the principal ingredient of the hard, light green rocks of the Blue Ridge, Southwest mountain and Green mountain, and of various minor ridges within a belt of about 20 miles east of the Blue Ridge, and is often found in those rocks in groups of delicate crystals. This also in some cases has been mis- taken for copper ore.

7. CHLoniTK. An unmizcd mineral, of a leek green or blackish

green colour, composed of minate Hcales of an eartfaj texture. It has the greasy feel of Talc, thoagh in a maoh less degree, and tnaj generally be distingnished from that mineral by not being separable into layers of such extent, and by its much more earthy appearance. Its ingredients are silex, alumina, magnesia, potash and oxide of iron — agreeing very nearly in composition, as it does strikingly in colour, with the substance found in New Jersey and in lower Vir- ginia called green sand. There seems also reason to believe that it resembles the green sand in its fertilizing effects, for in the soil of the Green spring lands of Louisa county, and a similar belt in Buck* ingham, remarkable for the greenish aspect of the land, much Ohio- rite is disseminated.

This mineral is much less abundant than those previously men- tioned, and occurs with us chiefly in a species of Gneiss, in the districts just named.

8. Steatitb, (a pure variety of soap ston.) An unmixed min- eral, of various shaaes of grey, white, green, yellow, &c., of which grey and white are most usual, the colours generally arranged in spots or blotches, easily cut, somewhat greasy to the touch, not in- clined to split in thin layers. It closely resembles Talc in appear- ance and properties, and, like that mineral, consists almost entirely of silex and magnesia. As is well known, soap stone is extensively applied in the arts, and for domestic uses, owing to the readiness with which it may be wrought into any required form, and its du- rability under an intense heat. As Talc and Steatite pass into one another by insensible gradations, much of the soap stone used is Tal- cose as well as Steatitio. This rock occurs in our primary region, at many points, in considerable extent, and of a quality to fit it for serviceable use.

9. ScHonL. An unmixed mineral, of a black colour and glassy surface. It is usually met with in the form of long crystals of about the thickness of a quill, maintaining the same thickness from end to end, and having from three to nine sides. When embedded in Quartz rock, as commonly found, its shining surface nnd its form render it very easy of recognition. It occurs at numerous points in Mecklenburg, Lunenburg, Amelia, Buckingham, &c., and is particu- larly abundant in the latter county in the neighbourhood of Willij's mountain. Its principal components are silex, alumina and oxide of iron. Specimens have been sent to me under the belief that it was anthracite cool.

10. Ktakite. An unmixed mineral, of various sliades of blue blended with white, the blue and white often presented in veins on the same specimen. The figure of the crystal thin, broad and fiat It is hard enough to scratch glass. The crystals ocrur closely grouped together, and crossing or standing on each other. It is composed of silex and alumina and is a heavy mineral, being more ponderous than Hornblende. Willises mountain is a remarkable

locality for this mineral, presenting it in great abundance, and of varioas hues.

11. SuTJHATB OP Babtta. A mineral usnally of a white or yel- lowish white colour, sometimes crystallized, sometimes finely gran- ular, in the former case slightly transparent, in the latter opaque. It is readily distinguished by its great weight, being even heavier than most iron ores. In the compact granular form it is readily cut by the knife, from which property, as well as its colour, it has been mistaken for gypsum, ana actually ground and applied to the soil. Its weight is nearly twice as great as that of gypsum, which would alone serve to prevent their being confounded. The chief use of this material is as a white painty for which it is largely consumed, particularly in mixture with white lead.

Nume];ou8 small, and some abundant localities of the Sulphate of Baryta are known in the southern district, among which may be cited the ridge between Beaver and Opossum creeks near Lynch- burg, and Bore Auger mountain in Bedford county. It also occurs in considerable quantities in Fauquier county.

12. Gabnet. a mineral of a red, yellowish red, or brown col- our, occurring in crystals vnrying in size from a pin's head to several inches in diameter. It is remarkable for the beautiful regularity of its form, and the number of its faces or surfaces, which varies from 12 to 24. By the uninformed a perfect crystal would certainly be pronounced the work of art. Its constituents are silex, alumina, lime and oxide of iron, the lime 20, the ox. iron 16 per cent. From the large quantity of lime present, it is a comparatively fusible min- eral, and hence some rocks in which it abounds may be used as an auxiliary flux for iron ores, having the additional advantage of themselves furnishing a considerable amount of iron. It occurs in some of the primary and metamorphic rocks very abundantly, and is met with in the southern region, particularly in rocks of the lat- ter class in numerous places. The neighbourhood of New Canton in Buckingham county, may be mentioned as an interesting lo- cality.

18. Granite. An unstratified or igneous rock generally found inferior to or associated with the oldest stratified and metamorphic rocks, and sometimes penetrating them in the form of veins and of dyieg or walls rising in the midst of them. The common rarieties of granite consist of quartz, felspar and mica, the first being the transparent, glassy ingredient, the second the white or pinkish mat- ter disponed to crumble, the last the shining ingredient in plates or scales. All these materials are crystalline and entirely exempt from indications of the wearing action of water. When the granite is coarse, the constituent minerals are very readily distinguished from one another by the naked eye, but in the varieties of a fine texture the microscope is sometimes necessary. Rooks of the latter descrip- tion are not unfrequently confounded with sandstone, and called by

that name. In the latter, however, the graiDS of qnartz are always more or less rounded or water worn, and when present the felspar is in a decomposed state, and the mica has lost its regular six-sided form. Talc and hornbleude sometimes take the place of felspar and mica, and are sometimes present in addition to the other ingredients. A true UDstratified granite, though ezteDsivelj displayed in some parts of our southern district, is by no means of common occurrence. As an example of it, I would cite the belt of whitish, hard, solid rock, extending from a short distance east of Little Falling river in Oampbell county with a breadth of between one and two miles across the Staunton river in the neighbourhood of Brookneal.

14. SiENrrs, is the name given to those varieties of granite in which the mica is nearly or entirely absent, or is replaced by horn- blende, and in which the felspar is relatively abundant. , It occurs in almost every variety and at numerous places throughout this region, embedded generally in the rock next to be mentioned. At Collin's ferry, Buffalo cr. and Whipping creek in Halifax and Camp- bell counties, a valuable variety is found composed of light or flesh coloured felspar, black hornblende and some quartz, but no mica. It is hard, permanent, with no disposition to decomposition, and occurs in large solid masses, seen projecting above the river and extending for some distance both above and below the ferry. It is here quarried for millstones, formed of a single piece, and is called mill stone grit, a name properly belonging to a sandy rock contain- ing water worn pebbles.

On the James river, four miles above Greenway, near Harrises- branch, there occurs in the bank a little away from the canal a body of dark sienite or sienitic trap in large irregular or glcbnlar masses, which are quarried for locks and culverts in this vicinity, Ihe rock is composed of dark green hornblende and white feispar, both dis- tinctly crystallized, and forms an admirable building stone easily dressed. The tendency to a globular form which these masses ex- hibit is very distinct and remarkable. This belt of sienite is of con- siderable breadth, and extends both ways in the general direction of the river for many miles. Other localities need not at present be specified.

15. Gneiss. A stratified rock composed of the same materials as granite, having a laminated texture. Usually, it has a much larger proportion of mica and less felspar than granite. It admits of numerous varieties in which hornblende, garnet, kyanite, &c. are more or less abundant. The rocks of this description are among the most common occurring in the southern district, and the continua- tion of the same region across the state. Owing to their stratified structure, many of these varieties admit of being quarried out in large and uniform slabs, the faces of which in many cases are thickly spangled with scales of mica. Gneiss rocks are in extensive use as building materials in nearly all the Atlantic states. In the sonthem district, they have been quarried below Columbia and between that

point and Lynchburg, and at varions other places, both for pablio and private construotions.

The qaarry immediately east of Colnmbia is situated in a hill from which a large amount of rock has been removed, principally for the construction of the aqueduct across the Kivanna river. The rock is here a grey granitic gneiss composed of thick beds, rolling from a nearly horizontal position to various directions of dip, the predominant of which as seen in the quarry is NW. The hill, viewed as a whole, presents an instance of globular concentric con- struction on a large scale, the layers of rock from 2 to 6 feet in thickness, appearing to be arranged in the form of successive shells, one upon another. This, which is a common feature in granite, as well as trap rocks, and seems referrible to the effects of heat, does not mark the true stratification of the rock, which in the present instance, though almost obliterated, would seem to have originally been in planes dipping to the S£. This in general is the direction in which the plates of mica lie in the rock, from which results the further peculiarity, that when we stand upon the undisturbed beds at the quarry, the edges of these plates only being exposed, the rock presents a light grey colour, but when we view a surface exposed by the transverse fracture, it presents innumerable black shining scales of mica.

A similar rock occurs extensively on the opposite side of the river in Cumberland county, where it has been largely explored in three quarries. In fact, all these quarries may be regarded as mark- ing the general position of a wide but variable belt of grey granitic faeiss extending for many miles both to the north and south of the ames river. Without attempting at this time to enumerate localities, or to enter into details in regard to this rock as examined at a great num- ber of places, I will briefly allude to a few of the belts or bands of it which have been traced.

The rocks in the neighbourhood of Halifax 0. H., and in a belt of country extending thence through Charlotte C. H. into Prince Edward county, are for the most part of this description. They contain much felspar, and are in general decomposed to some depth, forming a stiff clayey and sometimes gravelly soil, which is not pro- ductive, bands of hornblendic sienite occurring in various parts of it, as, for example, about Charlotte C. H., impart as usual a red tinge and more fertile character to the land. A short distance from Hali- fax C. H. on the road to Danville, this rock is boldly exposed im- mediately at the road. It is a dark grey gneiss, containing much felspar, and presents a striking instance of the penetration of such rocks by veins of igneous material. The two larger of these veins, consisting of felspathic granite, may be traced for many yards, and are seen crossing each otiier without any disturbance at the points of intersection, the smaller composed almost entirely of felspar in traversing the former, have occasioned a displacement of their op- posite or corresponding parts, so as to shift the vein about two mches aside from its former direction, indicating by this the occur-

rence of two BQCcessive intraaons of the igneous matter, the latter attended with the production of fissures crossing and displacing the veins previously introduced.

Near Danville another helt of gneiss of similar composition is seen crossing the river aboTe the bridge, forming the great falls, and extending northwestwardly, or in the direction of its breadth about a mile. This belt continues through Pittsylvania and Camp- bell counties.

A wide belt of micaceous and fel spathic gneiss traverses Albe- marle, Nelson, Amherst, Bedford, Franklin and Patrick counties, presenting frequent beds of granite and sienite, the latter more largely developed in proceeding towards the southwest. This zone, including the county seats of all these counties, extends on either side over an area of variable breadth, but sometimes reaching nearly to the Blue Ridge.

In all these belts of gneiss, much variation is observed in the ma- terials of the rock as exhibited at different places. Hornblende, talc, chlorite, kyanite, and other minerals occurring incorporated in the mass. Where the first is present in marked proportion, forming a hornblendio gneiss, the soil, as might be expected, is of a red colour, as may be seen in the vicinity of Nelson and Amherst courthouses. The chlorite, as already noticed, gives a greenish tinge.

It should liere be remarked, that in many varieties of gneiss dis- played throughout this region, a very marked amount of suJphuret of iron (iron pyrites) exists in the form of brilliant crystals dissemi- nated tbrongn the mass. This, as a general rule, impairs the dura- bility of the rock when used as a building material, because of the readiness with which these crystals are decomposed by the atmos- phere, and the softened condition of the mass they thus induce. Such rocks, however fresh and clear their surface when first re- moved from the quarry, in process of time become studded with small brown ferruginous specks, which gradually extend themselves HO as to injure the appearance as well as the solidity of the mass. As would be anticipated, the soil produced by the decomposition of gneiss of this description nossesses more or less of a reddish hue, but cannot be expected to display the agricultural character of that of similar complexion formed of hornblende, epidote, or other rocks abounding in lime. Hence, as is well known, there are tracts of red land noted for sterility, as there are others for their productive- ness.

An interesting variety of gneis is met with in Buckingham county, forming the chief mass of Willis's mountain and Wood's, improperly named on the map Appomattox mountain. When freshly broken, it is a whitish gneiss, composed in large part of quartz in grains, with a little mica, bearing some resemblance to a coarse sandstone, and containing a large amount of kyanite. The former mountain consists of two knobs with a low gap between. The beds of kyanitic gneiss are amply exposed on the top of both knobs in massive ledges, and in the steep precipices looking towards

the west, the dip of the strata being to the S£. at an angle of abo'Jt 75 degrees. Associated with these rocks are found schorl and mag- netic oxide of iron. From the peculiar character of this gneiss, and the abundance and variety of the kyanite and other minerals in and around it, this mountain is destined to become noted among miner- alogists. The following are some of the specimens collected at this locality :

1. Grey gneiss containing white kyanite, tinged red by iron.

2. White qnartzose gneiss containing kyanite.

8. Finely crystallized kyanite, occurring in groups forming large masses — white, bluish and yellowish grey, and brightly streaked with blue.

4. Schorl in large groups of crystals.

5. Actinolite, a bright green mineral in long slender crystal!*, found in a micaceous gneiss.

16. MioA Slate. By an increase in the proportion of mica, compared with the other ingredients, the preceaing rock passes into one possessing the slaty structure in a much higher degree, and which is called mica slate. In this the plates of mica sometimes compose nearly the whole of the mass, being merely cemented to- gether in parallel planes by a small amount of intervening quartz. In other cases the mica is less predominant, and some felspar as well as a large proportion of quartz are present, so as to furnish a mixture closely approaching to gneiss. In fact the passage Irom the one group to the other is by insensible gradations, so that by different observers the same rock is sometimes associated with them both.

As will readily be inferred, there is great variety in the composi- tion and structure of mica slate. As seen in our southern district, it sometimes presents the mica in conspicuous scales, but more fre- quently in minute ones, abundantly disseminated in the mass, and giving to the freshly exposed surface of the slate a glistening surface and a certain degree of smoothness to the touch.

The principal belt of this rock extends through Buckingham, Campbell and Pittsylvania, into Henry county, becoming less fully developed as it proceeds towards the southwest. In general direc- tion it conforms to the course of the James river between Soottsville and Lynchburg, passing across the river and expanding for some breadth into Nelson and Amherst counties, though not without the intervention of wide bands of sienite, gneiss, limestone, and another variety of slate presently to be described, in which the mica is either in part or wholly replaced by talc. As presented in Buckingham and Campbell over a breadth of about 8 miles, its predominant variety is a fine grained rock, in which the scales of mica are very small, and blended more or less with talc. Most usually it has the structure of a highly fissile slate, weathering into small fiakes or chips, but in many places it is largely intersected by veins of quartz and epidote, and then exhibits great hardness and a more imperfect slaty struc- ture.

For the most part the soils of this belt, varying from a light grer and greenish yellow to n mottled red coloar, are somparativelj an*

S rod active, but whenever the latter tint, nsnally prod need bj the ecomposition of the iron pyrites common in the rock, is acoom* panied with fragments of Epidote or Hornblende, indicating the source of the red colour, at least in part, better agricultural proper- ties are displayed.

It will presently be seen that limestone is of frequent occurrence near the western margin of these rocks, but within the general belt of which I am now speaking, no where could it have been pUced more opportunely for the agricultaral improvement of this district. For, perhaps, of all the soils tliroughout the southern region, none have naturally less calcareous matter than those derived from the light coloured slates referred to — and if we are to be guided by the expe- rience of those enterprising farmers living within this belt, who have availed themselves of this resource, none are more certain to derive amelioration from a judicious use of lime.

17. Talo Slatb. As already indicated, the micaceous slates of the belt above referred to, are often found to contain a portion of Talc along with the Mica, and such is the resemblance of the two minerals thus finely divided, that it is frequently impossible to pro- nounce upon the relative proportion in which tliey are severally present. When, however, the rock has the remarkable greasy feel and silken lustre of Talc, and exhibits few or no scales of Mica, it is called Talc slate— and where a marked, though perhaps not pre- dominating proportion of Talc is present, it is more properly termed a Taloose slate.

These slates are chiefly met with in the range of micaceous slates above described — sometimes occupying a very considerable width, and presenting the Talcose material in large proportion — sometimes contracted to narrow bands and consisting of an almost pure Talo slat, and sometimes passitig, as they are prolonged by msensible changes, into a less Talcose and more micaceous rock, until they ter- minate in genuine Mica slates.

18. AnoiLLACRous Slate. The aluminons and siliceous materials always more or less blended with the Mica and Talc in the slates above described, in many instances predominate so largely as to form nearly the only ingredients of the rock. In such a case, when the silex and alumina, in a finely divided state, are mingled throughout the mass, forming a slaty rock, in which little or no indications of crystalline texture are discemable, the slate thus formed is termed a clay slate, or Argillaceous slate. Rocks of this descriotion most frequently present a dark colour, and are reduced by weathering into thin and tender fragments, which quickly resolve themselves into a tenacious clay. They present, however, great variety in colour, texture and hardness, owing both to original differences in the pro- portion of the ingredients they contain, and differences in the de- gree to which igneous agency has modified them as to texture and

composition. As a class, the Argillaceous slates are to be looked npon as exhibiting less of this modifying inflaenoe than either of the metamorphic rocks aboTe described. As might be expected from the varying character of the slaty rocks embraced in the belt of which I have been Hpeaking, we meet with instances of gradual change from tiie condition of Micaceous and Talcose to Argillaceous slates, and rarely find the latter entirely devoid of Mica or Talc. In the neighbourhood of ScottsviUe, both above and below, are seen various mixed slates, presenting by turns the argillaceous, micaceous and tnlcose characters, but especially the two former. At numer- ous points along the eastern flank of the Green mountain, and in the western part of Buckingham county, as well as in Campbell, the argillaceous character is well marked. The admirable roofing slate quarried in the former of those counties, lies in another and more eastern belt of slate rocks, much less extensively prolonged than the main tract of which I have been speaking. Here, however, the compact Argillaceous slate of the quarry forms but one of the va- rieties of a group found in the same range, comprising Micaceous and Talcose slates. This slate, remarkable for its toughness and susceptibility of cleavage in broad thin sheets, bears evident marks of the indurating and other modifying effects of heat. It not un- frequently presents crystalline flakes and veins of Chlorite, spots of Epidote and small crystals of a peculiar mineral, Staurotide, which is met with at several other points in the Micaceous and Talcose slates.

19. Quartz Slate, or Qvartzite, Among the various modifica- tions of the slaty rocks now under consideration, deriving their dis- tinctive titles from the ingredient largely predominating in each, as might naturally be expected, there is one in which the silica or quartz remains almost alone. This still presenting the stratified ar- rangement, and to some extent, the slaty cleavage of the other rocks with which it is associated in position, and as it would also appear in origin, is not to be confounded with the clearly igneous quartz frequently found traversing in ramifying and intersecting veins, the gneiss and micaceous and other slates. It should rather be regarded as one of a series of products arising primarily from aqueous deposi- tion, for a time accumulating little else than siliceous materials, upon which at a later period, the modifying effects of heat were power- fully impressed. This Quartz slate is sometimes distinctly granular, presenting the aspect of a pure siliceous sandstone, having the par- ticles of sand partially fused together, sometimes it contains both Mica and Fels])ar in small amount — and by weathering, which removes the latter, becomes soft and porous. Not unfrequently it shows a fibrous structure, and the smootlied surface of a micaceous slate. In a word, it exhibits all the varieties of composition, and arrangement of parts, that might be inferred from the above view of its nature and origin.

This curious rock is displayed at various points along the James river, between ScottsviUe and Lynchburg, associated with Micaceous

and Talcose slates and limestone, and in a similar connection in the general prolongation of the same belt as far as Leesville in Bedford county. A few remarks apon some of the localities in which it is seen, will serve to shew its character and general range.

1. On the eastern edge of New Market, Nelson oountr, are two ledges of this rock, the larger and eastern of which is a little west- ward of the bed of marble near that place. The smaller, about 150 yards to the west, is separated from the former by beds of Talcose slate. The principal ledge is a fine granular whitish and reddish quartz, the other fine and coarse granular.

2. At the mouth of Owen's cr. and again a little above Green- way, a similar rock occurs, presenting with some changes the usual southeasterly dip of the rocks of this district. It is distinctly strati- fied, some layers quite solid and 2 or 8 feet thick, others in a state of decomposition, not crumbling, however, but retaining their origi- nal shape, having become externally of a dark colour, and porous within, from the removal of the felspar, which along with mica ex- ists in small quantity in the unchanged rock.

8. Lee's mountain about one mile west of Leesville, Bedford coun- ty, is composed of a fine granular qnartz rock, occurring in large lay- ers with a slaty structure, so that it easily rives out in masses or slabs of any required thickness and length. Its dip is generally to S£. at an angle varying from 60° to 80°. Some of the layers are quite hard, others softer and more easily dressed, and these are preferred by the workmen ; others again still softer shew a fibrous stracture like many of the talcose and mic. slates along the James river. The very summit of the ridge or hill is composed of the white rock in nearly vertical layers, and having been quarried in many places, it appears from below like a wall of sandstone. Indeed, consisting as it does of pure siliceous grains without felspar or mica, its resem- blance to compact rocks of that class is very striking. The prevailing rocks, both to the east and west of Lee's mountain are talcose and micaceous and argillaceous slates, and within half a mile in the latter direction occurs a bed of blue limestone, hereafter to be noticed.

Besides its beauty and durability as a building material, this rock would appear to possess such a power of resisting intense heat, as to fit it for employment in furnaces, in which application it is certainly deserving of trial.

20. Pseudo-Gneiss ob GmBissom Sandstone. The interesting class of rocks referred to under this title are remarkable for contain- ing rounded grains of quartz, and in tliis and other particulars pre- senting the general aspect of coarse grits or sandstones, more or less altered after their deposition by the agency of intense heat. These qnartzose grains are often larger than a pea, and in general of a milky vitreous aspect. The mass of the rock is made up of siliceous grains with more or less mica and with felspar, occasionally in dis- tinct crystals, so that according to the proportion and mechanical condition of the ingredients, it approaches in appearance either to a sandstone or a gneiss.

Daring decomposition, these rocks plainly betray their sedimen- tary origin, as well by the rounded pebbles of qnartz and sometimes felspar seen in relief on the weathered surfaces of the coarser varie- ties, as by the purely sandy soil into which they are ultimately re- solved. In many particulars they present striking analogies to the lower bedd of sandstone appertaining to No. 1, the lowest of the Appalachian series, where these beds are in immediate contact with igneous rocks on the western slope of the Blue Ridge.

The tract in which this interesting class of altered rocks chiefly occurs, lies near and within the western margin of the belt of mica- ceous and other slates before mentioned, and is bonnded by well de- fined strata of these rocks on either side. Witliin this tract are two ranges of the rocks in question, of which that lying more towards the east is situated immediately on tlie west of the Green mountains in Albemarle, extending in a southwest direction so as to cross Rockfish river about H miles above Morgans ford, and in a north- easterly direction through and a little west of the town of Char- lottesville. The other, separated from the former by a narrow band of talcose and steatitic rocks, pursues a parallel course, including nearly all of Findlays mountidn, and as it proceeds northeastwards, Fall Hill mountain, Applebury's mountain, and what near Char- lottesville is called the Ragged mountain, crossing the turnpike in a belt of more ttian half a mile in width. As might be expected, the character of the rock at different places within the ranges just described is liable to important variations, but in general features considerable constancy is observed, the rocks of the more eastern belt being for the most part of a finer grain and more gneiss-like character than in the other.

As from the facility with which in many places they may be quarried out in large and uniform slabs and rectangular masses, as well as from their beauty and durability as a building material, these rocks are possessed of much economical value, it will be proper in this place to present a few details relating to some of the localities in which quarries of them have been opened, and more or less explored.

Near the western flank of the Green mountain, the eastern of the two belts has been quarried at various points on the estate of Mr. Tucker Coles, and used in the construction of the upper works of the locks and culverts of the James river canal, as well as for various purposes in household architecture. The layers, dipping steeply to SE. are from 3 to 4 feet thick, of great uniformity, easily detached in large parallel blocks, which can be dressed with great facility. The rock is hard, firm, siliceous, of a very light grey col- our, with a few scales of mica and some specks of vitreous quartz, and evidently when properly selected of a durable character. West of this and immediately beyond the mill on Hardware river, occurs a (}uite coarse gritty rock, containing grains or crystals of felspar. This is separated from the former by micaceous talcose and other slates, and evidently appertains to the western belt above described.

In the gap of Warwick's mountain on Ruckers run, the rocks of

the belt just mentioned have been explored, to some extent at Patteson*s quarry, and here present the character of a hard siliceoua irandstone of a grey colour, in thick beds variously intersected by cross Joints tending to obscure the true dip, which as is general throughout this region, is towards the S£. They consist of bluish milky quartz, white felspar and some mica, presenting on their ex- posed surfaces the aspect of a coarse sandstone, and where freshly fractured looking somewiiat like a bluish gneiss.

At the end of Fall Hill mountain on the east side of Rockfish river, the same belt has been extensively explored by Mr. Bamum for the uses of the James river canal. The more eastern of these quarries, lying a little east of the mountain, consists of a brown micaceous gneissoid sandstone, with the usual grains of bluish vitreous quartz. The principal opening, situated at the end of the mountain, is one of the most extensive and interesting quarries in the state. The rock is a hard siliceous, whitish and grey sandstone, with little mica and c'ome crystals of sulphuret of iron, containing also occasional em- bedded masses of mica slate. The layers are from 10 to 12 feet thick, and of a uniform solid texture, well adapted for architectural purposes. This rock has been used in the construction of the aqueduct over tlie mouth of Kockfish river and elsewhere on the canal.

21. SoAPSTONE Rooks. In the remarks presented under the head of Talc and Steatite, allusion has been made to the variable compo- sition of the rocks commonly known by the name of soapstone. As occurring in our southern region, they consist in general of mixtures of talc and steatite, in proportions varying with the locality, passing on the one hand into simple talcose slates, and on the other into a somewhat pure steatitic mass. In that portion of their range, how- ever, lying chiefly in Nelson and Amherst counties, besides these in- gredients, they are observed to contain a small amount cf chlorite, and to be largely blended in some places with the greenish variega- ted rock, which, from its resemblance in gloss and colour to the skin of some snakes, is called Serpentine,

All the varieties of soapstone, though differing among themselves in texture and composition, are distinguished from other rocks by their smoothness to the touch, the ease with which they may be cut or otherwise wrought, and their capacity of enduring an intense heat without being fused or otherwise affected. Hence the various valu- able uses to which they admit of being applied, and the economical importance of such localities as afford them in the requisite purity. But n few openings have yet been made along the track in which they Hre generally found in our southern region, but at some of these the character of the rock is such as to recommend it to attention. It should however be borne in mind, that much of the mixed talcose, stoatitic and serpentine material found within this belt, is of too hard and uneven a texture to be of value for the finer purposes to which a 8oa])stone may be applied. In aid of the enquiries of those who may feel interested in exploring for rocks of this description, I will briefly

trace the tract in whicli they have been chiefly fonnd in the course of our examination in the soathern region.

Commencing in Albemarle county, we And a steatitio rock asso* ciated with the Talcose and other slates already mentioned as inter- vening between the two ranges of gneissoid sandstone, a little west of the Green mountain. It is here, as quarried by Tucker Ooles, esq., a tough, somewhat soft rock, of a mottled bluish grey colour fr from grit, sufficiently uniform in texture, and capable of being wrought with ease.

Following it towards the 8W., it is seen expanding in width and assuming a different and less valuable character by becoming largely blended with serpentine. In this condition forming a kind of bastard soapstone, still admitting however of being applied to the coarser usea, it passes immediately west of Ligons in Jelson county, where it consists in large proportion of the serpentine. Pursuing the same general line, it forms a narrow belt along the western base of Buf- falo ridge, in Amherst county, includmg in some cases the western portion of the ridge, and containing the copper ores and numerous curious minerals met with at the Folly and contiguous points. In this part of its range, it is for the most part a hai'd tough rock, yield- ing however some beds of a quality that might be wrought. Farther south it crosses the James river above Lynchburg, and shews itself about two miles westward of the town on the road leading thence to Liberty, and again about miles westward of New London. It is here of a greenish grey colour, containing but little serpentine. Con- tinuing in the same direction, it is seen at the meadows of Goose creek in the form of a grey talcose slate, associated with hard and impure talcose slates between it and Leesville. At the Meadows it is quarried as a soapstone. Still more to the SW. it appears in sev- eral nearly parallel ranges, of which the more eastern, pursuing the general direction hitherto described, makes its appearance about miles west of Brook's near the Pigg river in Franklin county. It is an impure greenish steatitic Talc slate, somewhat indurated. A second belt occuni in the same vicinity near the eastern base of Jack's moun- tain ; a third still farther west, about one mile from Franklin C. H. in a SW. direction, and a fourth yet more to the west on the eastern slope of Grassy Hill. Of these the locality mentioned next to the last furnishes the best material. It is a greyish steatite, occurring in large compact masses, and of a texture to be wrought without diffi- culty.

Farther south, these steatitic and Talcose rocks would seem to thin away. They are not seen on the road between Patrick and Henry courthouses, though there is reason to believe that near the Carolina border they again appear.

Besides the tract of Talcose and other slates just traced, there is another of less importance, also containing at some points beds of soapstone of a character fit for use. This lies east of the former, parsing in a southwesterly direction parallel to Beaver creek, and crossing Sycamore creek towards its source. In the latter neigh- bourhood a quarry has been opened, and is now worked to a con-

siderable extent, furnishing a soapstone of excellent qnalltj. It is a greenish grey, highly steatitio rock, of fine and even textare, entirely free from grit, and admitting readily of being sawed and planed, or otherwise wrought into the forms that may be desired.

22. MiOAOBons and Taloosb limestones and mabblbs. Included in the wide band of slaty rocks of whose various subdivisions I have been for sometime treating, there occur ledges and prolonged patches of strata consisting largely and sometimes almost exclusively of car- bonate of lime. These, from their high economical importance, as well as their peculiar features in a geological point of view, have been made the subject of very careful detailed examination, and are entitled to a prominent place in our consideration at this time.

The general position in which these limestone rocks occur, is some distance eastward of the range of the Talcose and Steatitic slates, though in this particular a rigid uniformity is not preserved. Fortunately for the value of these calcareous beds, as applied to the purposes of agriculture or the arts, the narrow tract in which they are found, corresponds in direction for about thirty miles with the general course of the James river below Lynchburg, and thus, at numerous points, reveals its valuable contents under circumstances the most favourable for applying them to profitable use. This feat- ure in their geographical position, derives additional interest from the fact that the portion of the tract thus brought to view, and as it were, explored by the river in its frequent changes of direction, is that in which the calcareous rocks are the most widely developed, and exist in the greatest variety as to texture, colour and composi- tion. Looking to the great advantages connected with such a posi- tion, and the extent to which these rocks may be made conducive to the private as well as public interest, it seems not a little remark- able that so few and such inefficient efforts have hitlierto been made to convert this invaluable resource to profitable use. At many points along or near the river, a material is amply exposed of sufficient purity for the mannfacture of lime suitable for architectural and household purposes — and almost every stratum of the rock is capable of furnishing a lime adapted to be used with great advantage as a manure.

Being the only tract of calcareous rocks within the wide area reaching from the Blue Ridge to the marl region of the eastern coun- ties, the importance of this belt, especially throughout the line in which it adjoins the James river, to the agricultural interests of a large portion of the state, is too obvious to have escaped even the most careless observation. Yet strange to say, few or no instances are known in which the extended region lying to the east, has been made to experience the benefits of which these calcareous rocks might be so fruitfully the source. But may it not be hoped that at no distant day, the real value of this calcareous tract will be practi- cally exemplified in the extensive conversion of its rocks into lime suited to the purposes of the farmer as well as the builder and engi- neer, and in tne employment of the material thus prepared, as a sub-

sdtute for that often intrinsioally of little higher Talne, now supplied to them from distant parts of the Union.

In thus adverting generally to the economical considerations which give peculiar interest to the narrow belt of which I am now treating, I would not have it to be understood that lime procured from the rocks in question, is often as free from impurities as the better kind of lime manufactured beyond our Blue Ride, or in many places in the eastern states. But I can confidently affirm, after nu- merous chemical examinations, that in many cases it is as well, if not better suited to the purposes of a cement, and will be found but little inferior when employed as a manure.

As an aid to the practical examination of this calcareous belt, and a means of comparing the different varieties of limestone it contains, I proceed to a brief account of its extent, and of the aspect and com- position of its rocks, as presented at some of the more important lo- calities which have been visited.

Allusion has already been made to the curious fact of the occur- rence of these limestone rocks in the form of oblong patches, and not, as in the case of this and other rocks beyond the Blue Ridge, in ledges or belts, prolonged continuously to great distances. This pe- culiar feature, which could hardly have been detected by merely casual observation, appears hitherto to have escaped notice, though it is one not without interest in connection with the economical value of the calcareous belt. In tracing the rock from any of the points at which it is exposed, in the direction of its bearing, or the strike of the strata, it will generally be found, after continuing some dis- tance, gradually to taper away, until finally lost in the contiguous rocks. An interval is thus presented in which the strata before ob- served are either entirely wanting, or have ceased to shew themselves on the surface, although, perhaps, at a small distance laterally from the line of direction of the lost beds, others of a similar character make their appearance, destined in like manner to expand and finally wedge out. A somewhat similar mutability has already been noticed as observable in the other rocks of the slaty belt in which these lime- stones lie, more particularly those of a talcose, micaceous and steatitic composition, whose range is near or adjoining to the limestones. It would seem, in fact, that in the original deposition of the various materials, including the calcareous matter, of which these numerous varieties of rock were formed, but little unifonnity prevailed in the substances accumulated at different parts of the tract at any one time, so that while at one place the materials were such as after- wards to form a Mica or Talc slate or steatite, or a mixture of two or all of these, at another, calcareous matter was collecting blended more or less with the other substances just mentioned, giving rise to limestones more or less micaceous or talcose in their composition, and towards the extremity of the tract in which they were forming, gradually fading away from the increasing predominance of the other materials there undergoing a like accumulation. It is, however, not to be inferred that the calcareous formation has ceased to exist wherever it is not present at the surface. Indeed, observation has

shewn that it may he so enclosed hj the meeting of the adjacent strata at tlie top, that nothing short of a section of some depth would reveal its presence. In sach a case, even thoagh the general dip of the strata were very steep, it might shew itself at the foot of a hill or in a pit, though entirely ahsent on the top or at the surface. In such cases, which there is reason to think are not uncommon, these calcareous masses may he looked upon as large bodies of rock re- sembling in form, though not in nature or origin, enormous flat and tapering pebbles embedded to a greater or less depth in the adjacent rocks.

By conceiving numerous masses of this description, some of them of many miles in length and several hundred feet in thickness, thus enclosed in the strata of that portion of the slaty belt in whicli they are found, we can readily imagine that the extent to which they are exposed on the surface, will be dependant on the position in which they are cut through by that surface, and by the natural sections formed by the rivers and ravines. From these considerations, a ready explanation is deduced of the frequent absence of the lime> stone in a line prolonged from and in the direction of localities where it is well developed, and of its recurrence at intervals in that and parallel lines, or of what may be called the sporadic occurrence of the rock. In thus dwelling at some length upon the want of per- sistency, frequently so remarkable in the rocks in question, I am in- fluenced as well by the wish to incite those interested in their dis- covery, and more particularly the farmers living near or within their range, to a diligent personal examination for them at every accessible point, as to render the geological conditions under which they occur familiarly understood.

The following brief details in regard to some of the more impor- tant exposures of these rocks, as they are seen successively in explor- ing the belt from the middle of Albemarle in a southwesterly direc- tion, will serve to illustrate the more striking features of the forma- tion, and convey useful information respecting the character of the rock at a number of valuable localities.

Commencing with the band of limestone exposed on Limestone run, inmiediateiy on the main road from Charlottesville to Rich- mond, we find the rock displayed over a breadth of about 100 yards, lying in a nearly horizontal position, but rolling a little towards the east. West of it is a bluish micaceous slate, on the opposite side a brown and rather argillaceous slate. The rock is a blue slaty lime- stone, with a little Mica and a few veins of white Spar. It is pene- trated in a vertical direction by a vein of grey impure limestone, and covered where the upper stratum has not been removed, by a grey rock containing but little lime.

From this point it extends with but little interruption, though of variable breadth, in a NE. direction, following nearly the course of the Mechnmp creek, in the neighbourhood of which it is quarried at several places. Where the Louisa road intersects its range it has disappeared, but a similar band shews itself at the surface at captain Lindsey's on the south fork of South Anna river, and near Gur-

donsville. In a 6W. direction it may Jbe traced without intermp- tion throQgh Dr. Blsdttermanns plantation, where it has been ex- tensively qnarried for agricultural purposes, and applied to this use with signal benefit It is here also a slaty blae limestone, contain- ing some Mica and Talc, producing a lime which, though not white, forms a strong cement. The enclosing rocks are talcose and mica- ceous slates, which, as well as the limestone, are inclined at a con- siderable angle to the SE. Thence in the direction of Buck island creek, it shews itself at several points in the neighbourhood of the stream, and is quarried by Mr. Garland and others, but before reach- ing the road leading from Scottsville to Garter's bridge, it vanishes, the last exposure being in the neighbourhood of Mr. J. D. Moons. It again appears about H miles NW. of Dyers mill at Limestone Place," consisting of a simcle bond of light blue slaty limestone about three feet thick, occurring in micaceous slate. It now crosses Ballinger's creek a little north of the margin of the red shale re- gion, and in a short distance enters that tract, where, if it exiHt at all, it is deeply covered by the red rocks. At Ballingers it is a light bluish grey slaty limestone containing a little Mica. A little west of the margin of the shales, it makes its appearance on Rockfish river near the mouth of Ivy creek, though in a belt lying westward of the former range, and still farther south a similar rock occurs at numerous points in the neighbourhood of Warminster on the James river.

The several parallel bands occurring in this vicinity, prolonged in the direction of their range or bearing, in other words, towards the N£. would enter the confines of the red shales a little lower down the river, so that even should they be continued in that direction they are rendered inaccessible by the overlying rocks. These bands moreover are not to be regarded as the continuation of the ranges of limestone previously traced, but lie some distance eastward of them, as may be seen by referring to the map.

From the vicinity of Warminster to Walkers ford, frequent ex- posures are met with both on the river and its tributaries, including many varieties of the rock, some of which have the texture and character of marble of good quality, and many are of sufficient purity to recommend them to use. Throughout this tract we perceive a multiplication of the number of beds and striking fluctuations in their thickness and composition at localities but little remote.

1. Referring to the more important of these exposures, we find the rock in beds of considerable magnitude, forming a cliff on the south side of the river at Traveller's Rest, the residence of major Yancey. The thickness of the limestone, as exposed at the quarry on the river side, is about 60 feet. The principal varieties occur* ring here are,

1st. Reddish close grained limestone.

2nd. Greyish compact granular.

8rd. Pink slaty micaceous.

4th. White slaty micaceous.

5th. Blue slaty micaceous, occurring a little lower down.

Much of the pink as well as the grey compact variety may be re- garded as of good quality, oontaiDiDg, as will be seen hereafter, a large proportion of carbonate of lime. Portions of the former oon- stitnte a not inelegant marble, though too mnch intersected bj veins to admit of being readily wronght.

2. Abont two miles below Warminster by the canal on the nbrth side of the river, three ranges of limestone are disclosed. The most easterly is narrow, composed of a whitish compact rock. The mid- dle range, about 40 feet in thickness, consists of bine slaty lime- stone with much calc. 8par. It is from this band that the iron works near New Canton are snpplied with the rock used as a flux. About 160 yards above is a smaller range of granular and compact limestone, white and pinkish, occasionally slaty, with some calc. Spar and a little Mica. All these rocks are associated with taloose and micaceous slates, and like the slates have a steep dip to NW.

Higher up the river, ledges of the rock are seen on Swift island, and crossing Stevens's and Pigsborough creeks a short distance above their mouths, the latter locality lying considerably west of the range of those previously noticed. This brings us to the vicinity of New Market, where numerous interesting exposures are met with on both sides of the river, and to some distance westward : and like exposures are seen from point to point as we ascend the river as high up as Elk island creek. The following are some of the particulars relating to this portion of the tract :

8. About one mile below New Market and 100 yards north of the road leading to Warminster, there occurs a bed of com{>act lime- stone or marble, which is well exposed where cut through by Pounding Mill creek. It lies between talcose and micaceous slates, and presents at this point a width of between 60 and 70 feet. It is in general a white rock, though sometimes pink or flesh coloured, and occurs in irregular layers, which are nearly or quite vertical. In texture and colour it is well suited for ornamental work, but it is to be feared that from the number of veins and joints running through the rock, it is not sufficiently solid for quarrying as a marble. Of this, however, no adequate trial has yet been made. The same bed is again exposed on the west side of Tye river near its mouth, form- ing several small ledges on the line of junction of the river bottom with the rising ground. It is just to the west of the direction of this bed that the curious ledge of qnartz rock formerly noticed pre- sents itself, and we shall see that a similar juxtaposition of calca- reous and siliceous beds occurs at other points.

4. On the south side of James river nearly opposite New Market, the cliffs or rocky banks for about half a mile contain blue slaty limestone, generally quite micaceous. These beds appear to be con- tinuous with those of a similar rock met with on the opposite side of the river above New Market along the canal.

6. Following the course of the river from New Market up, the blue slaty limestones just referred to are met with abont one mile above the village. They form two thin beds, separated by a con- siderable interval occupied by roic. and talcose slates. The fir is a

blae rock, containing reddish oalc. spar, width 10 feet— the second a blue slaty micaceous limestone.

6. Passing now a band of talc, and mic. slates, in the midst of which rises a narrow ledge of trap or greenstone, we come upon a bed of impure, white and pinkish compact limestone or marble, hav- ing a width of about 20 feet.

7. We are now carried snccessivelj over mic. slates and the bed of Sienite formerly referred to as atlbrdiug so vduable a material for bailding, and at the month of Owens creek strike upon another range of white Qaartz rock, mentioned nnder a former head. Be- tween Owens creek and Greenway we have for 2 miles argilla- ceons Elates, beyond these micaceons slates, and lastly blnish mica- ceous Gneiss, which is quarried at Greenway. Still farther on the micaceous slates and Gneiss continue for nearly two miles, except- ing where interrupted by a heavy interposed bed of quartz rock. At the termination of this distance, we again come upon blue slaty lime- stone.

8. We now have a succession of cliffs on both sides of the river composed of bluish mic. slate and Gneiss, the beds of which cross the river about three miles above Greenway; after which, near Harrises branch, there occurs a body of dark Sienite, which has been quarried for locks and culverts, and of whose admirable qualities I iiave already spoken. One mile farther on, we meet with two ranges of blue limestone, having a granular structure, and containing some brown Mica and white calc. Spar. They are enclosed in mic. slate and are about 20 feet in width.

9. This brings us in a short distance to a broad belt of marble 40 feet in thickness, consisting of a wliite and grey compact rock di- vided into layers from 8 to 4 feet in thickness, ond of uniform text- ure and great solidity throughout, dipping to S£. at an angle of 60°. This forms a cliff which is cut through by the canal. In texture, colour and solidity, this rock gives every indication of being well adapted to be wrought as a marble, and can hardly fail to become valuable for this or other purposes.

10. Beyond the marble we again pass over Mica slates, and with- in a quarter of a mile of Elk island creek, meet with a bed of blue limestone veined with calc. spar. This, as exposed, has a width of from 40 to 50 feet— dips also to SE. Micaceous slates recur, and just at the mouth of Elk island creek, we find another but thinner bed of blue limestone. Which is quarried.

11. At the distance of about half a mile above the mouth of Elk island creek, near the furnace of he Elk creek irf 'U manufacturing company, a blue slaty limestone occurs in the vicinity of the ore bank nearest to the establishment, and a similar rock is met with in several narrow parallel belts for some distance westwards. Expo- sures also occur at some points within the triangular space lying be- tween Buffalo ridge and the James river and Elk island creek, whose margin has now been traced. These beds however appear to have thinned out before reaching Christianas creek.

12. On the southern side of the river a belt of limestone is seen

crossing Back island creek abont half a mile above its month, and anotiier more westerly bed is exposed at Walkers ford nearly oppo- site tlie month of Christian's creek. This is blue and slaty, and as- sociated with talcose and micaceons slates.

13. The calcareous beds having now thinned away on the north- ern side of the river, appear to undergo a correspondent expannon on the southern. On Stonewall creek, a short distance below Ross's furnace, and about 2 miles in a direct line from the river, a belt of limestone is exposed, measuring at this place upwards of three hun- dred feet in thickness. It is blue, sometimes sparry and white, sometimes granular, and inclined to be crystalline. This belt pos- sesses great importance, not only on account of its extent, but its contiguity to the extensive beds of rich iron ore which are nsed at the furnace, the limestone lying a little east of the most eastern band of ore.

14. Continuing our observations up the river, we meet with a range of blue limestone, generally slaty and micaceous, about half a mile below the mouth of Archer's creek. The principal varieties occurring here are,

First — Greyish sub-crystalline limestone containing small rhombs of calo. spar.

Second — Dark blue slaty limestone, micaceous, containing small rhombs of dark calc. spar, and some iron pyrites.

Third — Blue slaty limestone, micaceous.

Ttie thickness of the bed may be estimated at 70 feet

16. About 2 miles above the mouth of the creek, near where the old Richmond road crosses, and therefore in a position more to the east than any of the beds hitherto noticed, we find exposures of a quite thick belt of blue limestone, both at the ford of the creek and some distance beyond. This rock, which is enclosed by micaceous slates, has a high dip S£. It is blue, micaceous, somewhat slaty, and contains some calo. spar.

16. The belt described as shewing itself a little below the mouth of Archer's creek (14) would appear to be prolonged, though seem- ingly not continuously on the surfaces, in a direction to intersect Opossum creek at the point of crossing of the Richmond turnpike near its mouth, and at that of the road to Campbell courthouse, at botii of which places a bed of bluish micaceous limestone is exposed. The same is also seen at various places in the line connecting these points, between Opossum and Beaver creeks. As seen near the crossing of the Richmond road, it shews itself in a bold cliff on the creek, in thick, solid layers dipping SE., having at the quarry a width of about 50 feet, and being bounded by mic. slates on both sides. It is deep blue, dull, micaceous, and with thin layers of Mica between the strata.

17. Tl>e belt described as crossing Archer's creek, some distance above its mouth on the old Richmond road, would also seem to be prolonged, though not continuously at the surface, making its appear- ance on Little Beaver creek, which it crosses, and shewing itself ex- tensively along the western margin of Big Beaver as far up, nearly,

as where the road to Oampbell coarthonse crosses the creek. At captain Stephen Perrow's this belt is about 100 yards wide, and consists of grey, bluish, and white limestone. The bluish or clouded generally contains Mica and iron pyrites, and grains of bluish Quartz ; the white is fine gruned, pure, and free from Mica, and in fact, is a marble of moderately good texture. The same rocks are seen about half a mile below on the land of Dr. Stevens adjoining the creek,, and are here bounded on the west by a belt of micaceous slate in which occurs a bed or vein of fine granular Sulphate of Ba- ryta of a pure white colour. On Chiltons plantation the limestone crosses Beaver creek, soon afler which it strikes over to Uttle Bea- ver, but soon becomes concealed, so that it is not well exposed again nntil we approach Archer's creek. . Between Cbiltons and Little Beaver it is a coarse grained white and grey and bluish lime- stone.

18. West of the mouth of Opossum creek, about midway between it and Licking, several narrow bands of limestone shew themselves near the river, being the only representatives in this part of the tract of the belts of marble and limestone found in the neighbour- hood of Elk Island creek, Greenway and still lower down. The strata as exposed from the mouth of Archer's creek to the western termination of the cliff in which these bands occur, present some points of interest, and may therefore be briefly alluded to in the order in which they occur.

Immediately above the month of the creek is an extensive ex- posure of light blue Mica slate, with embedded Mica in dark scales. The bearing or range of the strata is N£., and the dip steep towards south and east. A large vein of Quartz is finely displayed in the tace of the clifi, cutting through the strata at right angles, thus evincing its intrusion as an igneous material into the beds of Mica slate after their deposition, and furnishing a beautiful illjistra- tion of the relation of much of the Quartz rock of this and corre- sponding districts of the state, to the surrounding mineral masses. A large proportion of this Mica slate is well suited for building, being procurable in large uniform blocks capable of being dressed with ease.

Between Beaver and Opossum creeks are exposed beds of Quartz rock of very dififerent character and origin. These present them- selves in heavy strata, enclosed by Mica slates on both sides, and dipping in conformity with the slate, at an angle of 45° to 8£. The whole thickness of the rock is about 200 feet, consisting chiefly of two bands of 100 feet each, separated by the slates. This rook is dense, fine grained, containing a little Mica, and in some layers em- bedded grains of bluish Quartz, presenting the characters of an altered sandstone. It has been extensively wrought at CabelPs quarry for the works on Beaver creek.

At Opossum creek we have bluish micaceous slate, and in about half a mile a cliff begins which extends for about 2 miles along the canal. Here we have bluish and greenish mic. slates with veins of Quartz, grey micaceous slate, and then the most eastern of the bands

of limestoDe, which is about 7 feet thick, bine, slaty and micaceous, with some spar. The position of this band is vertical, bat it does not rise to the top of the adjoining slates, which fold over it so as to present a thickness of about 10 feet between its termination and the surface, displaying in this particular, a feature in regard to theso beds of limestone formerly adverted to, as probably characterizing them very generally.

About 50 yards above this is another ledge 5 feet wide, of light blue slaty limestone.

A little beyond the last, is a third bed consisting of white and grey rather granular limestone, looking like marble, but wanting solidity, being slaty and penetrated by seams. Thickness about 10 feet.

Adjoining the former is bluish Talc slate, west of which we meet with a fourth bed, coniisting of a white slaty limestone in thin layers covered with a film of Talc. Thickness 20 feet.

Beyond this is dark green Talc slate with wrinkled surfaces, and then a curious bed of micaceous Gneiss, with a great deal of Quartz, about 20 feet in thickness, rising from the base of the cliff in a ver- tical line, then bending so as to become horizontal, and again by a similar rectangular turn rising vertically to the summit

The narrow bands of limestone here described are not prolonged to any considerable distance towards the southwest, and no doubt thin out in that direction as well as towards the northeast.

19. Tracing, in a southwestern direction, from Beaver and Opos- sum creeks the tract of slates with which the calcareous beds have thus far been observed to be associated, we find numerous expo- sures of limestone in two ranges, one following the general course of Flat creek, the other that of Buffalo. The former or more east- em range may be seen near Homers about 9 miles south of Lynch- burg jon the Pittsylvania turnpike. It occurs over a considerable space in the flat meadows at the head of the creek, and is here a blue limestone forming a tolerably white lime. Below this it may be traced from point to point as far as the Otter river near the mouth of the creek, shewing itself well at Mr. Wards on a small creek above Quarry branch, and at Scott's mill, judge Saunders's, and major Smith's on Flat creek. The breadth of this belt, though far from uniform, is very considerable : the rock as seen at judge 8aunders*s is blue, slaty and micaceous, intersected by small veins of Quartz, and dips at about 40° to S£. Adjoining it are Talcose and Micaceous slates.

20. The range on Baffalo creek is separated from the former by an interval several miles in width, occupied by mic. slates with Epidotic and Hornblende rocks and Quartz containing beautifully crystallized Schorl.

The limestone is seen at several points on the creek. On Mr. Andrews's plantation it forms a narrow band in mic. slates and Gneiss, and is a white granular limestone with some Mica. At Mr. Ro. Irving's it forms the face of the cliff on the side of the creek, and has a width of about 80 feet, dipping to S£. It is of various

teztares, from a coarne granular to a slaty fine grained limestone of a grey colour, and forms a white lime.

21. The helts above described as ranging along Flat and Baffalo creeks, thin oat in proceeding SW., so that the latter does not reach the Otter ri-ver, and the other disappears atler passing through Dr. Haydens plantation south of that stream. But lower down the river ttian the range of the Flat creek rock, there occurs at the mouth of Scott's creek, on the plantation of captain Tardy, a bed of limestone of sufficient extent to form a cliff near the Otter. It is a bluish granular rock, shewing itself in heavy beds.

22. On Sycamore creek near Clemeiit's ford of Staunton river, a thin bed of white granular and slaty micaceous limestone is exposed, enclosed in micaceous slates, but this soon thios away, and no rock of this description has been met with in this direction further to the SW.

23. lo the prolongation of the line of the Buffalo creek rock, however, though not continuous with it, a bed of limestone makes its appearance near Goose creek, between one and two miles above Leesville, sitnated at its mouth. It presents itself about half a mile west of Lee's mountain, of whose layers of beautiful Quartz rock mention was formerly made, and as exposed at Mr. Arthur's quar- ries, has a thickness of about 40 feet. It is blue and slaty, but not micaceous, contains some calc. spar, and barns into a white lime. Dips to S£. at an angle of 60°, and is in contact with greenish Mica slate. A similar rock occurs near the southern base of Smith's mountain, on the plantation of Prof. Tucker.

24. Following the general direction of the tract, we meet with one other bed of limestone, near the ford of Pigg river, a little above the mouth of Glade creek in Franklin county. It is blue, slaty, oc- casionally micaceous, and with small layers of calc. spar. Width about 15 feet. It is quarried for the use of the furnace at Rocky Mount. Further to the southwest the Talcose and Micaceous rocks, always observed to be associated with the limestone, rapidly thin out, and no traces of them or the limestone are to be seen in cross- ing Patrick and Henry counties, from Martinsville to the furnace on Goblintown creek. Whether these rocks re-appear still nearer the state line has not yet been determined, though it is not improbable that such is the fact, as at no great distance south of the line they are met with in North Carolina.

The foregoing details, comprising the principal, though not all the localities of calcareous rock within the district of which I am treating, have been given at some length, with the view of inducing those who reside within or near the tract in which these rocks oc- cur, to make diligent examination in their respective neighbour- hoods, that any bitherto concealed beds, of which it is by no means improbable some may yet be found, may be brought to light and turned to useful account. The minuteness of our researches as manifested in some of the above details, has been such that I am confident no belt of considerable thickness has been passed over — but even a band of this rock of only a few feet wide, may prove an

itnportaDt acquisition to the agriooltare as well as the honsehold economy of a neighbourhood, and would oertainl/ well repay the trouble of exploration.

From that portion of the above details relating to the numerous exposures on and near the Jarnes river, particularly when connected with the chemical results in regard to the composition and peculiar qualities of those rocks which are to follow, it would seem scarcely to admit of doubt that the beds of limestone and marble met with in that portion of the tract, are destined hereafter to be of more than merely local value, and that they will not be suffered to remain so little wrought, when their highly favourable position gives them an advantage more than compensating the inferior excellence of the rock at many, though by no means, at all the exposures.

As a very useful aid to those who are interested in the above details, and who desire to trace the calcareous be<ls through inter* vening points not mentioned, as well to readers generally, anxious to follow underntaiidingly the descriptions I have given, I would recom- mend a continual reference to the large state map while reading them, as I have endeavoured so to specify localities as that they may be fixed with sufficient precision on the map. For the sake of per- manent future reference, it would also be found useful to make a distinct mark with a pen or brush at each locality thus determined ; and I would take the liberty of recommending a similar procedure where boundary lines of formations are traced in the reports. Such visible demarcations, while greatly assisting the reader in forming clear conceptions of what is described, become parts of the geologi- oal picture of the region, whose purport is afterwards recognized at sight, and in the present case may serve a purpose of use as well as gratification, until the geological map of the state is in the hands of the public.

Compontion and properties of the Limestones and Marbles

ahove referred to.

Numerous specimens of these rocks, gathered from all the im- portant localities visited during the last and preceding seasons, have been selected for chemical examination, and of a portion of them our analyses have already been completed. From the results, as stated below, it will be seen that in many instances they contain a large proportion of carbonate of magnesia, a fact which, taken in connection with their siliceous character, led me at once to infer their capability of furnishing a lime suited for the purposes of a water cement. I have accordingly instituted a series of experiments designed to test their properties in this respect, and though the in- vestigation will require some further time to bring it to maturity, I am enabled to announce the fact, that the rock of some of these beds yields a hydraulic lime which, though it sets slowly, forms a solid cement. I may further state what has been mentioned inci- dentally before, that the grey and reddish lime of many of the poorer beds, containing some magnesia as well as much siliceous matter,

will be fonnd to form a mortar for common purposes of eater hardDoss and dorability than can be made by the use of the pnre white lime, which is so generally preferred ; and that though com- paratively few of these beds will yield a perfectly white lime, it should be borne in mind that tlie light grey and cream coloured limes produced from some of the richer rocks, are little if nt all in- ferior in strength to the white limes in common use. Of the falsity of the opinion so prevalent that a coloured lime must of necessity be of inferior strength, no clearer proof oould be adduced than the well known fact, that the presence of less than one per cent, of oxide of iron in the lime is sufficient to give it a very decided red- dish or brownish tinge.

23. Ibon Ores. On this head only a few observations can be usefully presented at the present tune, as the chemical examinations relating to these materials are as yet too little advanced to furnish a body of analytical results sufficient to illustrate their composition and probable economical value. The extensive beds of these ores fonna at some points in the southern region, their great richness in iron, and their proximity in several instances to some of the belts of limestone above described, together with the favourable position in which some of them are placed as regards water power and facili- ties of transportation, give them a not unimportant rank among the mineral resources of this portion of the state. These deposites are however by no means so numerous in this region, as from the deeply ferruginous tinge of the soil over extensive districts, and the fre- quent occurrence of loose fragments of ore upon the surface, ordi- nary observers have been led to imagine. All the slaty rocks of which I have treated above are more or less impregnated with iron, usually shewing itself in the undecompoEed rock in the form of crystallized sulphnret of iron or iron pyrites, and in many instances bearing a large proportion to the other materials with which it is intermingled. Nor is it exclusively confined to the class of rooks in question, occurring sometimes in equally marked amount in beds of Gneiss and in veins of Quartz, particularly such as have been found to contain gold. This mineral may be known by its yellow- ish metallic lustre, and the generally cubical or square form of its crystals. Though worthless in itself, it would appear to have been the source whence some of the most valuable and extensive ore beds of this region have been supplied.

The beds referred to are those consisting of the brown and ochre- ons ores hereafter to be mentioned. A few remorks upon what would seem to be the theory of their formation will, I hope, not be deemed inappropriate as a part of the prettent bnef sketch of the geology of our southern region.

The brown and ochreous iron ores contain the metal in the state of an oxide, and are made up of this oxide, together with silex, alumina and water. The oxide contains 70 per cent, of metallic iron, so that were the ore composed of this alone, each himdred pounds ought to yield seventy pounds of metal. In the richer ores

BB inQcb SB 85 per cent of the oxide b sometimes fouid, the re- maining 15 per cent, consisting principally of water. This would correspond to about sixty pounds of iron to the hundred of ore, and is an amount scarcely ever obtained in the operations of the furnace.

The ores in question are uniformly found associated with Mica- ceous or Talcose slates or Gneiss, in which the sulphuret is or has been present in great quantity. In the immediate vicinity of the bed, these rocks are seen in a decomposing condition, and impreg- nated with ochreous matter, which is the material of the ore. In fact, with a little attention, the various gradations may be traced from the unchanged rock, at some distance from the bed, to the softened and decomposing material in which the sulphuret has dis- appeared and the dark brown stains of oxide are presented, and thence to a mixed substance consisting of the matter of the rock, with a predominance of the oxide, from which we pass into the massive and comparatively pure ore. Of the stages of chemical change by which this conversion would seem to have been brought about, the first is obviously the decomposition of the sulphuret of iron, and the production of copperas or the sulphate of iron, an effect continually witnessed where moisture and air have access to the sulphuret, and the second the separation of the brown oxiile from the copperas, probably in some measure by the action of the magnesia and potash present in the Mica, Talc and Felspar of the adjacent rock. In this view of their production, the ores in ques- tion are to be regarded as of much later origin than the adjacent rocks, and indeed as being in some places in progress of formation now. Striking examples might be referred to of beds of Micaceous and Talcose slates, in which knots of such ore are to be met with disseminated through the mass, and still in part retaining the struct- ure of the slate, so as to exemplify one of the stages of change be- fore noticed, in which the production of the bed of ore has not yet been carried to its completion.

Besides the brown and ochreous ores, there occur also two other varieties, viz: the Micaceous oxide and the Magnetic oxide. The former is not unfrequently associated in small quantity with the ores first mentioned, but most commonly occurs in small veins included in Quartz. It is distinguished by its glistening scaly crys- tals, not unlike those of a dark brown Mica, but unlike these it yields a bright reddish brown powder when bruised, and will stain the fingers of this hue when robbed. Though of common occur- rence, it is not found in large quantities. The composition of this ore is the same as that of the pure brown oxide, but unlike that variety it is never united with water.

The Magnetic oxide, when pure, is richer in iron than either of the preceding, containing within a small fraction of 72i per cent, of metallic iron. It is diotinguished by its nearly black colour in mass as well as when reduced to powder, and its strong action on the magnetic needle, attracting one extremity and repelling the other. It is from ore of this description that nearly all the Swedish iron, so

celebrated for its excellent qualities, and bo well suited for ooover- sion into steel, is extracted.

This variety of iron ore occurs at several points in the southern region in the form of beds or strata of considerable thickness and of good quality.

The following enumeration of some of the exposures of these ores may serve to indicate their geological position as well as their extent and general characters :

1. In Buckingham county an extensive bed of the brown and ochreous ore has been traced for many miles in a direction south- westwards of the furnace near New Canton. Of this deposit some account was given in my first report.

Omitting further details at this time, I would merely remark that from its continuity and thickness, and from the general richness of its contents, this bed deserves to be considered as of high econorai- cal value. The iron made from it is for many purposes regarded as of good quality, though like roost of the metal manufactured from the ores east of the Blue Ridge, it requires the admixture of a softer material in converting it into bar iron. The position of this bed between Micaceous slates, and the graduation of the ore into slate along the sides of the bed, afford good illustrations of what has been said in regard to the origin of these ores.

2. In the same county a bed of the brown ore is extensively posed on Stonewall creek in sight of Mr. Rosses new furnace, and shews itself at several other places in the neighbourhood. At the furnace it has a width varying from 10 to 15 feet — at Mr. Yeatmans, half a mile below, its width is 12 feet. Its position is nearly verti- cal, included in yellowish Talcose slate, and its range or bearing is N. 20° £. The ore is generally compact and dense, but sometimes cellular, and containing ochre. Higher up the hill and eastwards of the former, another pardl'el bed occurs, consisting chiefly of a yel- low ochreous oxide of iron with numerous and large cavities. SStill more towards the east we meet with the range of limestone for- merly spoken of, furnishing a flux to be used with the ores.

8. Near the mouth of Elk Island creek in Amherst county, two or more considerable beds of ore are met with, the more eastern of which, about half a mile Above the month of the creek and a quarter of a mile above the furnace, is from 4 to 8 feet in thickness where explored, and is a brown oxide of iron, sometimes micaceoas, con- tained in Mic. and Talc, slates. Half a mile westward occurs an- other bed, consisting principally of slaty and micaceous ore, and at various points in the vicinity bog ore is abundantly met with, serv- ing a nseful purpose in union with the compact and micaceous ores. As already stated, beds of limestone are found within a short dis- tance of the ores.

4. A little east of the belt of grey granite, formerly described as ranging through Campbell county near the Charlotte line, and cross- ing the Staunton river at Brookneal, there occurs a prolonged bed of ore, similar in character to those above described. Abont n mile N£. of coL Hancocks dwelling, the width of the bed is 8 feet, but

there is reason to believe that at some points it swells out to more than double this amount. It here ranges in a NN£. direction, has a high eastern dip, and is associated with Mica slates. The ore is a brown oxide, sometimes quite compact, sometimes oohreous, and occurs in large masses on the east side of Hot (Hat, £d.) creek, (one of the branches of Falling river,) near its mouth, much ore is seen on the surface, and has been exposed by diggings — apparently the continuation of the bed explored on col. Hancock's land and its vicinity.

6. Near Rocky Mount in Franklin county, a little north of the bed of Steatite formerly described, the Magnetic oxide occurs in sufficient quantity to supply a fhmace in the vicinity. The ore is granular, of a black and greenish black colour, and is associated with decomposing micaceous slates — width of the bed varying from 4 to 6 feet. Another bed of the same description, several feet in width, is met with a little north of the village. Impure bog ore occurs in the neighbouring meadows, yellow and oohreous, ac- companied on the surface with the grains called shot ore. Seven miles west of the village we meet with the brown oxide in Mica slate.

6. In Patrick county, a little west of Goblintown creek and on the east side of Stewarts Knob, we find the magnetic oxide exposed at several places, the main deposit supplying the Union iron works in the vicinity, being a bed of from 8 to 6 feet wide, of a fine grained, generally black ore, sometimes having a greenish tinge from the in- termixed scales of Talc, and sometimes red and ochreons.

7. In Buckingham county, about a mile east of Whispering creek and nearly in a line with Willis's mountain, a heavy bed of the mag- netic oxide crosses the road leading from Maysville to Ca Ira, and may be traced for some distance in a N£. and 8W. direction. It is from 6 to 8 feet in width, solid and dense, generally bright and specular, though sometimes dull. It affects the needle powerfully, and is evidently a very rich ore.

Further details in regard to these, and a similar full account of other localities, are reserved for a future time, when the chemical examinations connected with the subject, shall have been brought to maturity. But it will bo seen from the particulars which have now been stated, that the portions of the southern region referred to are by no means wanting in supplies of this mineral, and that some of the most extensive beds are very favourably situated, both as regards the limestone so essential in the manofacture of iron and an easy conveyance of the products of the furnace to market

Bocki exposed in a Geological Section, extending from the Blue Ridge at 7 ye Biver Gap to Cumberland CourtJtouse. Course SJS, 68 miles.

The Blue Ridge at Tye river gap is composed of several mount- ains which unite with the main ridge on the eastern side, and by the road is 12 miles from the western to the eastern base.

Beginning at the western base of the moantaiiif we find the eandstones and slates of No. I. with a high dip to the NW. These rocks of No. I. occupy a small hill jnst west of the foot of the mountain, and extend a short distance np the side of the Bine Ride; their width as exposed along the road is fths of a mile. Next succeeds a broad range of whitish Granitic rocks, soft and decomposing, and presenting no evidence of stratification. Thej continue for 8 miles to the sum- mit of the ridge, and about 1 mile down the eastern side. These decomposing rocks contain frequent beds of Epidotic granite, and especially of a beautiful dark grey Syenite, which latter is frequently porphyritio, and contains crystals of Felspar 2 inches in length. These beds of Granite and Syenite are composed of hard, permanent rock, in large irregular masses, not stratified. There are also noticed two broad bands of sandstone and slate. That on the western side occurs about one mile below the summit, is about 200 yards in width, and consists of grey and reddish slates, some- times micaceous, with associated layers of sandstone, conglomerate, greenstone, and greenstone slate. The greenstone is sometimes amygdaloidal. These layers are horizontal, and with a moderate dip to the SE. The other band ocxsura about i mile below the summit on the £. side, and presents repeated alternations of red and grey slates, white sandstones and conglomer- ates. They are nearly vertical, with a high dip to the SE., and in width extend half a mile 4 miles.

Oontinuing down the eastern side of the Blue Ridge, we find grey Granitic rocks occasionally inclined to de- composition, with several bands of Argillaceous slate, and towards the eastern base two or three dikes of greenstone 4 miles.

From the eastern foot of the Blue Ridge, at the junction of the N. and S. forks of Tye river, to about 2 miles SE. of Lovingston. the country consists principally of Gneiss rocks, whicn about Lovingston contain frequent beds of hard and durable Granite. General dip is high, to the SE 14 miles.

The next 3 miles of the section exhibits greenish chloritic Granite, Gneiss, and bluish Mica slate, which are ver- tical, and strike NE 8 miles.

This brings us to Findlays mountain, about one mile in width, consisting of coarse Siliceous sandstone in ver- tical strata. This range of sandstone is quarried where it crosites Rucker's run, a few miles SW. from this point, and also to the NE., where it crosses Rockfish river. This rock, at Patterson's qnarry on Rucker's run, is a hanl grey Siliceous sandone, in large irreg>

nlar masses, and unequalled in durability. The exten- sive qaarries of Barnnm on Rockfish river farnish an excellent stone, easily dressed, and occurring in masses of any required size. Along the eastern side of this ridge occurs a range of Micaceous Gneiss, which is also quarried by Barnum, and a little £. of Patterson's, at Variety mills. All of the rock from these quarries is called Granite," and has been extensively em- ployed for the construction of locks, aqueducts, upon the James river canal 1 mile.

Between Findlay's mountain and Warminster, 4 miles, we cross just £. of the mountain a range of Micaceous Gneiss and Mica slate, which are vertical with a strike to the N£. — then a range of Soapstone or 8teatitio slaty rocks, also vertical, — then a range of Greenstone succeeded by grey Micaceous Gneiss, which is about 2 miles in width, and extends nearly to Warminster. It is quarried and used for the common structures of the canal at the latter place 4 miles.

At Warminster the rocks are Mica slate with a high west- erly dip. In Yancey's cliff, on the £. side of James river, immediately opposite the village, a belt of lime- stone is exposed having a width of about 75 feet. It occurs in thick layers or strata which are highly in- clined and rise up from the river to the height of more than 100 feet. Several varieties occur here, white, reddish and blue, and varying in texture from close granular to slaty and micaceous. It is quarried exten- sively for the locks and other works on the James river canal. Dip NW. The country along the section, from Warminster towards Maysville consists of Micaceous slates with frequent beds of Gneiss. The dip soon changes from a westerly to an easterly one, and so continues to Maysville. West of Maysville we cross a range of Hornblende slates, which furnish a rich red soil. At Slate river, near the village, we come again upon Mica slates 15 miles.

From Maysville to Willis's mountain, 9 miles, the line of section crosses Micaceous and Talcose slates, especially the latter, which contain frequent veins and beds of Quartz, some of which are auriferous. This is the Gold belt of Buckingham county. The slates dip at an angle of from 80° to 60° to the SE 9 miles,

Willis's mountain is double, and consists of two knobs with a low gap between. It consists of a whitish Gneiss, generally quartzose, sometimes micaceous, which abounds in whitish Oyanite disseminated through the whole mass of the rock, and frequently in crystals. The rock composing Willis's mountain dif- fers from all in its vicinity, and appears to have been

elevated from below throngh the surroanding slatets. The western face of both knobs is precipitous from midway to the top, and the eastern side of the north- em or larger knob presents the same character, fix- posed sart'aces of the rocks acquire a reddish fernigi- nons stain and some of the slates about the base of the smaller knobs have such a ferruginous aspect, that the absence of proper weight will alone distinguish them from ores of iron, upon a mere inspection. The rocks of Willis's mountain dip 20° to NW., while the Mica slates and Gneiss which surround it all have a dip, and generally a high one to the S£ 1 mila.

From Willis's mountain towards Ga Ira the section passes over grey Gneisses with a high easterly dip, which are traversed by several ranges of Greenstone. About miles west of Ga Ira the section crosses a narrow range of red sandstone, which lasts nearly to the village. This range consists of red Shale and Gonglomerate, and contains embedded globular concentric masses of Greenstone. Dip of these red rocks is gentle to the SW., and the dip of the slates on each side is S£. They are evidently a deposite of not much depth, mere- ly filling a hollow or basin in the Micaceous slates be- low, upon the edges of which they rest unoonformably. The section crosses near the northern termination of this narrow range of sandstone, which continues south and west by Farmville to beyond Prince Edward court- house, and there becomes associated with a black Shale containing seams of bituminous coal 8 mOes.

Between Ga Ira and Gnraberland courthouse the rocks con- sist of grey Gneiss, sometimes arenaceous, with a gen- tle dip S£., as at Willis's river and Rocky run, and to- wards Gumberland courthouse they appear as white felspathio Gneiss, decomposing and furnishing much porcelain or china clay. Dip gentle S£ 6 miles.

Section Iv.

OF THE MIDDLE 8EC0KDARY RAKDaTONKS, SHALES AND CONOLOM" EBATE8 OF THE SOUTHERN DISTRICT—EAST OF THE BLUE RIDQB,

Ghaptes 1. General Features of this Formation.

The rocks of the formation here referred to, though differing greatly among themselves as to the nature and mechanical condition of the materials of which they are composed, are distinguished from all others in this region by peculiar and well marked features.

Iq the first place they are obviously made np of the re-nuited materials of other and of course older rocks, in fragments of all di- mensions, from the minutest grain to masses weighing many pounds, sometimes associated in strata of comparatively uniform texture throughout, and sometimes very heterogeneonsly assembled.

The coarser materials of these strata are distinct and easily recog- nized fragments of Granite, Gneiss, Hornblende slate, Mica slate, Epidote, Quartz and other rocks, such as are nsuaUy met with in the wide belt of country extending from the eastern flank of the Blue Kidge to the head of tide, and stretching in a southern and south- western direction through the Oarolinas far into the state of Georgia; The more comminuted matter is identical in composition with the grey, yellowish, red and particoloured sands and clays, produced by the decomposition of the rocks referred to, and which are to be met with very generally covering them to a greater or less depth.

All the larger fragments, and even the particles of sand entering into the composition of these strata, present more or less of a rounded outline. This feature is most strikingly displayed in such fragments as are of a nature to be readily worn by mutusl attrition, or by the agency of moving water, as for example. Hornblende slate. Mica slate, Chlorite slate and Gneiss, all of which are usually met with in the form of oval pebbles, while the fragments of Quartz, a much harder rock, embedded beside them in the same mass, are seen to retain their sharp edges and projecting corners almost unaltered. In frag- ments of very large size this configuration is less conspicuously seen, though even these, while preserving much of their rectangolar or polygonal form, exhibit unequivocal proofs of the same wearing agency.

While much variety is displayed in the colour of these strata as presented in different localities, the predominating tint of the entire range of the formation is a deep brownish red, not easily distin- guished from the hue of those soils in the surrounding region, which owe their complexion to the decomposition of the prevailing Epi- dotic, Homblendic and Trappean rocks. This more usual tint is often seen alternating with shades of grey, yellow and green, and in some cases % over wide tracts is almost entirely superseded by them.

In general tlie conglomeritic structure, though of frequent occur- rence, is confined to comparatively narrow portions of the belt occu- pied by these strata, the majority of the beds being made up of sand- stones and shales, composed of siliceous and argillaceous particles mingled in various proportions, but in most cases the former being present in large excess. The loose coherence of these ingredients leading to the rapid disintegration of the strata when exposed to the weather or to denuding agencies, has caused tlieir extensive destruc- tion near the surface, and has imparted a glsdy character to much of the region over which they spread. As might be anticipated from the texture of the soil thus formed, as well as of most of the under- lying rocks, the region of these shales and sandstones is deficient in bold and steaily springs, and though covered with a soil of ea cul-

tiyatioii, and of some fertility in the lower levels, is pecnliarly ex- posed to injury in seasons of drought.

Being exclusively of sedimentary origin, and containing at many points both animal and vegetable remains, the middle secondary strata would at first view appear to be closely allied to the sand- stones, shales and conglomerates of some of the Appalachian forma- tions as presented in the hills and valleys on the other side of the Bine Ridge. Geologically considered, however, they belong to a later epoch in the physical history of oar continent than any of the groups of strata in that portion of the state, or even in the region extending thence to some distance beyond the Mississippi. Of their position in the scale of secondary formations it will be sufficient for the present to observe that while the widely expanded coal measures of our Trans- Alleghany region which extend over our western coun- ties and a large portion of eastern Ohio, and in virtue of successive gentle undulations, are again repeated in the vast coal basins of In- diana and Illinois and of Missouri, are admitted to occupy a station low in the series of secondary formations, and while another group of strata, including the green sand and rotten limestone of New Jersey and Alabama, exposed in certain districts of these states, as well as of Tennessee and Mississippi, and elsewhere, are placed in the highest position in this series, the rocks of which I am now treat- ing bear evidence of an intermediate geological date, and hence have been denominated by professor H. D. Rogers and myself the middle secondary formation.

Before describing in detail the limits of the interrupted belt or series-of large islands formed of the middle secondary strata in the southern district to which I am now particularly referring, it may be well to remark that in the explorations of a former season, the same formation was met with in the northern portion of the state in a nearly similar position in regard to the Blue Ridge, but though crossed at that time in various places in Culpeper, Fauquier and Prince William counties, and examined with some attention in par- ticular localitiea, the general objects then in view did not admit of a connected series of observations for determining its boundaries, and the various details relating to its structure and composition. But though these accurate results remain for the labours of another sea- son, enough was then observed to furnish the means of comparing the formation there exposed with that recently explored in all its details in the southern district, and to give the fullest assurance of their identity. That it is not unimportant to have clearly ascertained this fact, will readily appear when it is considered that the forma- tion as presented in the northern district of our state is prolonged into Maryland, stretches witili little or no interruption entirely across that state and Pennsylvania, traverses New Jersey as far as the Paliisadoes on the North river, and there is every reason to believe is again presented in the valley of the Oonnecticut, while its south- em portion in Virginia, after being interrupted near the state line, quickly reappears and extends in considerable breadth for some dis- tance into North Garolioa.

In oomparing the strata of the discontiiiiionB tracts occupied by this formation within our own borders, onr deductions, foanded npon an examination of the materials, stmetnre and dip of the roclca, in all of which a striking resemblance is every where preserved, have been not a little aided by the occasional discovery of oiigaDic remains. Thas the black polished rhombic fish scales, fonnd in the bituminous shales near Farmville, and at Leakesville in N. Carolina, and in Fauquier county, and the minute shells found in a dark slate near Floumoy's in Prince £dward and at Leakesville, together with various impressions of vegetable origin, have sen'ed to give validity to the conclusion otherwise deduced of the identity of the forma- tions at these remote positions.

The rocks of this formation in Virginia being confined to a belt of country removed to some distance eastward of the Blue Ridge, while, except in a single instance, the lower members of the Appa- lachian series no where spread eastwardly from the great valley into the same region, our middle secondary is never met with adjoining or overlying the Appalachian rocks, as is frequently the case in Maryland and Pennsylvania. This entire separation of the two is important in explaining the comparatively small amount of calcare- ous matter in the form of pebbles or minute particles contained in the rocks of that portion of the middle secondary which traverses Virginia. In New Jersey, Pennsylvania and Maryland, the shales of this formation are calcareous, and the coarse conglomerates are largely made up of pebbles of limestone identical in character with the beds of that rock appertaining to the Appalachian series, occur- ring in the adi'oining and surrounding region.

The well known Potomac marble, a highly ornamental rook, composed in great part of such fragments, united generally by an in- tervening reddish shaly material of a more or less calcareous com- position, though forming in Maryland a conspicuous portion of the middle secondary strata, and often occurring in thick beds in the same geological connection in Pennsylvania and New Jersey, is seen rapidly changing its composition as it is prolonged towards the south, presenting comparatively few limestone pebbles in Fauquier, still fewer in Culpeper, only here and there a single fragment in the neighbourhood of Barboursville in Orange county, and no massive and very little diffused calcareous matter in its extension through the counties south of the James river. Yet so marked a resemblance of the coarse conglomerates in many portions of this region in which they are almost devoid of calcareous matter to the Potomac rock, produced the similarity in the cementing material and in the non- calcareous fragments of the two, that at a little distance they might readily be confounded. As a striking instance of this general like- ness, I would point the observer to the interesting series of ex- posures presented along the line of the James river canal for some miles below the mouth of Hockfish, in which the character of this conglomerate as it occurs in this portion of the middle secondary is finely displayed, not only on the faces of the newly bared cliff, but in the piles of large fragments on the river side of the canal.

A feature of mnoli interest in the geology of this formation, is the almost nniversal prevalence of a NW. or NNW. direction in the dip of the strata, a fact which has heen observed not onlj through- oat the region more particularly referred to in this place, but at all the other exposures that have been examined within the state. The same direction of dip has been noticed by myself in these rocks in the southern part of Maryland and in North Carolina, and has been traced over a much greater extent of the formation by my brother professor H. D. Rogers, in the course of his minute explorations in rennsylvania and New Jersey, where this group of rocks is devel- oped on a wider scale.

This interesting fact viewed in connexion with the nature and mechanical condition of the materials composing these strata, sug- gested to my brother early in his investigations in the states before mentioned, very important inferences, since fully sustained by mj observations in Virginia as well as Maryland and Carolina, as re- gards the directions in which the powerful currents flowed while conveying the detrital matter to the region in which it was depos- ited as now seen layer upon layer in conforming slope, and the geo- graphical position of the territory from whose surface these mate- rials were washed and torn away. Without entering at large into these deductions, of which an extended account would be inappro- priate in this place, it may for the present be remarked, that nearly if not all the matter of which these strata are composed, may with confidence be traced to the wide primary region lying to the south and east ; the currents coming in from that direction, besring with them the red soil and coarser materials so abundantly furnished by the Hornblendio and other rocks there extensively spread out. These transported matters would appear to have been conveyed into a pro- longed estuary or trough having a general direction from SW. to N£., and being deposited in successive layers commencing at its southeastern margin, would naturally assume the attitude of strata dipping to the northwest.

It not a little curious to observe that strata apparently apper- taining to a corresponding formation in Nova Scotia and New Bruns- wick, and consisting of materials analogous to those of our middle secondary rocks, are described as very generally presenting the same northwesterly dip.

Before concluding this short sketch of the most interesting gen- eral features of the formation, I would call attention to what I con- sider the true explanation of the important fact, already incidentally mentioned, of the non-existence of limestone pebbles, or even of diffused calcareous matter in any considerable amount in these strata as presented in our southern counties. Tins explanation I conceive is found in the absence of calcareous rocks throughout the region lying towards the southeast of this portion of the formation. The buids or ovoid patches of Micaceous and Talcose limestone, ranging near the southeastern margin of the middle secondary in most of the belt of country through which it passes north of the James river, continuing their general direction nearly in a line with

the long reach of this river between Scottsville and Lynchburg, make their appearance in the connties farther soath to the north- west of this formation, at the distance of several miles from its near- est boundary. So long as any of thesp limestone beds are found ex- tending along its eastern verge, limestone pebbles are to be met with in the conglomerates, and even where these beds have thinned away to an insignificant layer, such fragments occasionally present them- selves. Moreover, the resemblance of these pebbles to the calca reous rocks from which they are supposed to have been derived, affords a striking confirmation of this view of their origin, and thus also furnishes a strong argument in favour of the inference of my brother in regard to the direction in which the materials generally of this formation were transported, lliese facts considered, it would seem reasonable to conclude that the non-existence of lime- stone in the region lying to the southeast has been the cause of the almost entire absence of calcareous matter in the southern portion of the formation in Virginia, and that in its prolongation south, this ingredient is not to be looked for unless where bands of limestone, having the required position, are presented.

Chapteb 2.

Boundaries of the Middle Secondary Formation in the

Southern District,

In proceeding briefiy to describe the limits of the formation aa developed in this portion of the state, I would premise that the sar- face covered by it is not in the form of one continuous belt, although

Srobably snch was the case when the strata were firwt deposited, ut consists chiefly of two oblong tracts, the one extending from tbe state line near the southeast corner of Henry county, with an inter- mission of some miles near the line, to a point a little below the month of Rattlesnake creek in Campbell county, thus covering the southeast angle of Henry county, passing entirdy across Pittsylva- nia, and more than half way across Campbell, and in its course en- croaching a little on the NW. angle of Halifax county; the other lying eastward of the prolongation of the former, traversing the northern part of Prince Edward county from a point about four and a half miles SSW. of the courthouse to the Buffalo river above Farmville, but broken in this distance by a wide interval in tbei neighbourhood of Kings tavern, thence ranging through the south- west corner of Cumberland, and at the same time spreading over into Buckingham county, skirting Willises river in the former, and terminating at a point about two miles north of Ca Ira.

A little northwest of the direction of the former of these tracts, snpposing it to be prolonged, the formation again appears about a mile below Warminster on the James river, thence extending with an increasing breadth and a direction bending around more towards the east along the northeast comer of Kelson, covering a small strip on the south side of the James river, and its great bend, in Bucking-

ham ooimtj, and passing throngh the aioining comer of Albemarle, whence it continaes into Flay anna, where, within a short distance of the line, it terminates. The northeastern portion of this tract, or that lying in Flovanna county, as well as part of the adjacent re-

S'on covered by the same formation in Albemarle, not having yet traced with snffioient roinateness for defining their limits, will be omitted in the following details.

Trttet of the Middle Secondary lying in PitUyhaniay Halifax and

Campbell Counties,

Measured from the state line to its termination in Campbell connty, omitting the hiatus between the villages of Cascade and Bachelor's Hall, the length of this tract is alK>nt sixty -two miles. At its widest part, near Riceville in Pittsylvania, its breadth is rather more than six miles, bnt this does not continue long in either direction. Its average breadth may be estimated as about four and a half miles. This therefore would make its area about two hundred and eighty square miles.

Beginning at the state line, the boundary of that portion of the tract south of the interruption before spoken of, which portion is in fact but a continuation of the formation which in North Carolina follows the course of the Dan river, passing through Leakesville, Sawratown, &c., may be traced by a line drawn about a mile east of Cascade creek and nearly parallel to it, passing through a point a little east of the village of Cascade, thence turning westwardJy so as to cross the creek about five miles from the state line, and sweep- ing around to a southwestern direction, intersecting Smithes river near the same line.

Between the termination of this area on the N£., and the re- appearance of the formation at the 8W. extremity of the White Oak mountain, is a space of about three and a half miles in width, in which only primary rooks are to be seen, though circumstances strongly indicate that the strata of the middle secondary once ex- tended continuously across it, and have been removed by the violent denuding power of one of those currents, by which at various points the formation appears in former times to have been deeply lacer- ated or swept away.

Northeast of this interval, in the formation, its limits are marked out by a line drawn entirely around it in such manner as to haye the directions and pass through the points enumerated below.

From a point about one and a fourth mile to the north of Bache- lor's Hall, where the line is supposed to commence its course, it is for acme distance westward, then infiected in passing around the end of White Oak mountain, so as to form a curve, maintaining a nearly uniform distance (one mile) from the road leading to Dallas's bridge. Taking now a nearly straight course as far as Bannister river, it atretcbes along the northwest flank of the mountain about one mile east of Fitzgerald's and of Chestnut's store, crossing the river about the same distance below the mouth of White Oak creek. From this

the long reach of this river between Scottsville and Ljmchbnrg, make their appearance in the comities farther soath to the north- west of this formation, at the distance of several miles from its near- est boundary. So long as any of thes limestone beds are found ex- tending along its eastern verge, limestone pebbles are to be met with in the conglomerates, and even where these beds have thinned away to an insignificant layer, such fragments occasionally present them- selves. Moreover, the resemblance of these pebbles to the calca- reous rocks from which they are supposed to have been derived, affords a striking confirmation of this view of their origin, and thus also furnishes a strong argument in favour of the inference of my brother in regard to the direction in which the materials generally of this formation were transported. These facts considered, it would seem reasonable to conclude that the non-existence of lime- stone in the region lying to the southeast has been the cause of the almost entire absence of calcareous matter in the southern portion of the formation in Virginia, and that in its prolongation south, tliis ingredient is not to be looked for unless where bands of limestone, having the required position, are presented.

Ohapteb 2.

Boundaries of the Middle Secondary Formation in the

Southern District.

In proceeding briefly to describe the limits of the formation as developed in this portion of the state, I would premise that the sur- face covered by it is not in the form of one continuous belt, although Srobably such was the case when the strata were firwt deposited, ut consists chiefly of two oblong tracts the one eztendiuff from the state line near the southeast corner of Henry county, with an inter- mission of some miles near tlie line, to a point a little below the month of Rattlesnake creek in Campbell county, thus covering the southeast angle of Henry county, passing entirely across Pittsylva- nia, and more than half way across Campbell, and in its course en- croaching a little on the NW. angle of Halifax county; the other lying eastward of the prolongation of the former, traversing the northern part of Prince Edward county from a point about four and a half miles SSW. of the courthouse to the Buffalo river above Farmville, but broken in this distance by a wide interval in tbei neighbourhood of Rings tavern, thence ranging through the south- west corner of Cumberland, and at the same time spreading over into Buckingham county, skirting Willises river in the former, and terminating at a point about two miles north of Ca Ira.

A little northwest of the direction of the former of these tracts, supposing it to be prolonged, the formation again appears about a mile below Warminster on the James river, thence extending with an increasing breadth and a direction bending around more towards the east along the northeast comer of Kelson, covering a small strip on the south side of the Jamea river, and its great bend, in Bucking-

ham oonnty, and pasaing throngh the adjoining comer of Alhemarle, vhenoe it continaea into Flnvanna, where, within a ahort diatance of the line, it tenninatea. The northeaatem portion of thia tract, or that lying in Flavanna county, aa well as part of the aaoent re-

S'on covered hy the rame formation in Alhemarle, not having yet traced with anfficient minntenesa for defining their limita, will he omitted in the following details.

TVact of the Middle Secondary lytTig in Pittsylvania Halifax and

Campbell Counties,

Measnred from the state line to its termination in Camphell connty, omitting the hiatns between the villagea of Caacade and Bachelor's Hall, the length of thia tract is about sixty-two miles. At ita widest part, near RiceTille in Pitteylvania, ita breadth is rather more than six milea, but thia doea not continue long in either direction. Its average breadth may be estimated aa about four and a half miles. This therefore would make ita area about two hondred and eighty square miles.

Beginning at the atate line, the boundary of that portion of the tract aouth of the interruption before spoken of, which portion is in fact but a continuation of the formation which in North Carolina follows the course of the Dan river, passing through Leakeaville, 8awratown, &c., may be traced by a line drawn about a mile east of Cascade creek and nearly parallel to it, paasing through a point a little east of the village of Cascade, thence turning westwardly so aa to crosa the creek about five miles from the atate line, and sweep- ing around to a southwestern direction, intersecting Smithes river near the same line.

Between the termination of this area on the N£., and the re- appearance of the formation at the 8W. extremity of the White Oak mountain, is a space of about three and a half miles in width, in which only primary rooka are to be seen, though circumstances atrongly indicate that the strata of the middle secondary once ex- tended continuously across it, and have been removed by the violent denuding power of one of those currents, by which at various points the formation appeara in former times to have been deeply lacer- ated or swept away.

Northeast of this interval, in the formation, its limits are marked out by a line drawn entirely around it in such manner as to ha7e the directions and pass through the points enumerated below.

From a point about one and a fourth mile to the north of Bache- lor's Hall, where the line is supposed to commence its course, it is for aome distance westward, then inflected in passing around the end of White Oak mountain, so as to form a curve, maintaining a nearly uniform diatance (one mile) from the road leading to Dallas's bridge. Taking now a nearly straight course as f ar aa Bannister river, it stretches along the northwest flank of the mountain about one mile east of Fitzgerald's and of Chestnut's store, crossing the river about the same distance below the mouth of White Oak creek. From this

vicinity it assumes a more northerly direction, crossing Ofaerrj Stone creek about two and a half miles above its month, passing on the east within two miles of Pittsylvania coarthoase, (Competition on the map,) then about one mile east of the White Thorn tavern, where it crosses White Thorn creek, and thence turning still more to the north to the main road at Georges creek, and after this with a sudden eastern bend to Chalk Level. Recovering its origii&al direction by a quick bend, after leaving this point it crosses Staun- ton river a short distance above the upper end of Long Island, passes near the mill on MoUys creek, intersects the road leading from Campbell courthouse to Reid's bridge on Falling creek, about one and a half miles from the bridge, and with a very gentle curve reaches the northeastern extremity of the tract near the mouth of Rattlesnake creek on the same river.

Turning now to the south to form the boundary on the south- east, this Ime soon assumes a direction but slightly diverging from its course on the opposite side of the tract, passes miles west of Nowlan's, thence in a nearly straight course across Staunton river about half a mile below PannePs bridge, thence with some gentle flexures to a point to the west and within a half a mile of Rioeville. From this point it bends gently around more towards the west, so as to diminish the width of this portion of the tract intersecting the road leading from Danville through Pleasant gap in the White Oak mountain, at the distance of about five and a half miles from Dan- ville, and after a southeastern turn, which brings it within three quarters of a mile of the Dan river, sweeps around with rapid curve to the point a little north of Bachelor's Hall, where it commenced.

Tract of tTie Middle Secondnry lying in Prince Edwad Cumber'

land and Buckingham Countiee.

As already mentioned, this area is interrupted by a wide interval in the neighbourhood of King's tavern, extending for a distance of about two miles, measured in a north and south direction by a line passing through King's, the space thus bare of the middle second- ary strata being occupied by Mica slate. Gneiss, Granite, Sienite and other rocks, altogether of a primary character.

A short distance south of the courthouse we come upon the northern margin of these strata, forming part of the boundary of a small oval patch whose greatest length, from N£. to SW., is not quite two miles. This on the east is marked by the course of tiie Briery river, which flows along and sometimes a little within its margin. On the west it extends to within from a half to three quarters of a mile of the main road from Charlotte courthouse to Farmville, having for its greatest breadth a line of about a mile in length, passing through a point known as Flournoy's coal pit.

The main tract of the formation in this part of the state, com- mencing about half a mile north of King's, is bounded on the west, as far as Bufialo river, by the road leading in a K£. direction from Hampden Sidney college to that stream, and on the east by a line

Dar1y parallel to Buffalo creek, and distant from it about half a mile, terminating at the Appomattox river on the edge of Farm- ▼ille. In the wedge shaped area between the Appomattox and Buffalo rivers, the strata of the middle secondary have been nearly all removed or covered by alluvial material, bnt north of the former stream they are again exposed for a distance of about one and a half miles, extending from a point upon the Bizarre estate about half a mile above Farmville, up the river to within a few hundred yards of the point marked on the map as Sandy Ford bridge. The tract north of the river has for its eastern boundary a line running nearly due north from the point on the Bizarre estate already re- ferred to, passing a little west of the intersection of the Clover Forest road and that leading from the turnpike in a western direc- tion to Dry creek, and crossing the former about a mile from the intersection just mentioned, then turning towards the east and run- ning again northwards from a point about three quarters of a mile west of Raine's tavern in Oumberland, to near the intersection of Little and Great- Willis's rivers, whence, with a nearly NE. course, it extends west of Ca Ira about a quarter of a mile, crosses Rainess creek near its month and reaches the northern extremity of the tract about midway between Kaine's and Buffalo creeks.

From this point the line in question turns rapidly through a K W. to a SW. direction, crossing the Ca Ira road about a mile and a half from Oa Ira, intersecting Great Willis's river about a mild east of Kurdsville in Buckingham county, passing immediately east of Mrs. Hendriok's, and thence taking a nearly due south direction to the point below Sandy Ford bridge before mentioned.

The entire length of this irregular tract, from the most southern exposure of the strata in Prince Edward, to the most northern in Cumberland county, may be stated at twenty-two miles. Its greatest breadth, to wit : in the parallel of Kurdsville, is about four miles, and its average width approximately one and a half miles, making an area of about thirty square miles.

From these details in regard to the boundaries of the tracts in question, it is believed that by a careful reference to the state map, an accurate picture may bo formed of their geographical position and extent, and I would respectfully recommend to such as are interested in the subject, to read the above details, pencil in hand, so as to trace upon the map the limits thus marked out.

Cbaptsk 8.

Characters and Contents of the Middle Secondary Strata in the

Tracts aibove described.

Of the structure and composition of the rocks of this formation, as found in other parts of the state, and in other states, a general account has already been given, in the course of which also particu- lar reference has been made to the chief peculiarity presented in the strata as developed in the tracts now unaer consideration.

For the more particular illastration of their character and con- tent?, it will be sufficient for the present to select a few facts from the large body of details collected.

Commencing with that portion of the formation lying near the state line, and to the south and west of the village of Cascade, the prevailing rocks met with in crossing the tract are dark red, yellow- ish, and grey sandstones, and blackish slates, with bat little rock coarse enoagh to be called a conglomerate.

The following details of a section from Cascade dne west across the formation indode the principal strata here met with :

1. A short distance east of the village, on a small run, occurs a blaish slaty sandstone, immediately adjacent to which, on the east, are heavy beds of coarse Granite.

2. Next we find a dark sandstone alternating with a dark com- pact slate, slightly calcareous.

3. Next deep red sandstone, very slightly calcareous.

4. Next a dark bluish brown slate, with layers of argillaceous sandstone, somewhat similar in hue.

5. Next fine red sandstone, argillaceous, and slightly micaceous, followed by a coarse red sandstone.

6. Next yellow slaty sandstone followed by soft red argillaceous sandstone of a fine grain, to which succeed the primary rocks bound- ing the formation on the west

In the prolongation of these rocks in a southwestern direction into North Carolina, heavy beds of blackish soft slate or shale make their appearance, and are well exposed at the bridge over the Dan river just above the mouth of Smithes river. These shaly strata con- tain indistinct impressions of vegetables, and very perfect casts of a delicate bivalve shell, and are underlaid by several layers of hard slaty rock which is somewhat calcareous.

The dark colour and rather carbonaceous character of these shales has given rise to the opinion that they contain a valuable seam of coid, for the exploration of which operations have, it is un- derstood, been actually commenced. At Linseys, three miles above Leakesville, in shales of the same character, which are here observed frequently to alternate with red and grey sandstones, two shafts have been sunk in search of coal, and a .mall seam of dark carbon- aceous matter has been explored, consisting of alternating layers of coal and slate, the aggregate thickness of the former probably not exceeding one foot. It is a non-bituminous coal, generally compact and lustrous, and bearing a striking resemblance to a very common variety of the Pennsylvania anthracite. Its composition in the 100 grains is as follows :

Carbon, 83.12

Volatile matter, 7,76

Ash, 9.12

As from the partial success that has attended the explorations in the vicinity here referred to, some incentive might seem to be justly furnished for undertaking similiu* enterprises in pai-ts of the same for-

mation widiin the limits of Virginin, it was thought proper to direct particolar attention to the aboe localities, notwithstanaing they lie beyond the geographical boandaries of the state. I may therefore mention as the reeiut of these enquiries, that from the facts observed, no reasonable hope can be deduced of finding either at the points re- ferred to, or in tne neighbonring portions of the formation in Vir- ginia, any seam of sufficient thickness and extent to prove of real economical importance. The existence of carbonaceous layers con- taining small portions of coal, sometimes of great purity, at various points in the range of this formation, far from being ininrobable, is what might naturally be expected from the views fdready stated as to the origin of the materials composing the middle secondary strata in general. But looking to the fact already stated, that the rocks in question belong undoubtedly to a later epoch than that of the great coal formation of this and other countries, an epoch marked by the deposition of strata distinguished for their barrenness of vegetable as well as animal remains, no encouragement to expensive enterprises of research can be derived from these merely local, and as it were, aoddental accumulations of vegetable matter.

Remarks similar in purport to the above, published in my annual report some years ago, were suggested by a mere cursory examination of the formation as disclosed in Fauquier, Prince William and Cul- peper, though at the time but an imperfect knowledge of the geolog- icid character of this formation had been attained.

The examinations since made in various parts of the middle secondary tracts in Virginia, as well as those of my brother in Penn- sylTania and New Jersey, have only served to establish the truth of the opinion early formed as to their non -productiveness in coal to any valuable amount. It is therefore hardly necessary to remark that the same views are to be applied in regard to the indications of coal, and the thin seams of coal and carbonaceous matter met with at some places in the middle secondary strata of Cumberland and Prince Ed- ward counties, to which particular reference will hereafter be made.

Becurring to the strata of the southern tract, and pursuing them north of the hiatus formerly noticed, we find them largely composed of dark and light grey sandstones, which with an intermixture of red slates and sandstones, constitute a considerable ridge called White Oak mountain. These rocks, spreading to some distance from the fianks of the mountain on both sides, and forming a glady and sandy region, are sometimes coarsely conglomeritic, a feature here as well as generally throughout the formation, most conspicuously dis- played along its western verge. Of this, an interesting example is seen where the Dry fork, one of the branches of White Oak creek, is crossed by the road. The conglomerate at this point consists of large fragments of Granite, Gneiss and Quartz. At George's creek, near Ghk Level, this rock presents the curious character of a soft red sandstone variegated with yellow and white, in which are em- bedded, as in a paste, large rolled masses and pebbles of light red Granite, flesh coloured Felspar, Talcose Granite, Gneiss, and red, white and blue Quartz.

Where the formation attains its greatest breadth, which is nearly in the line joining Ohalk Level and Riceville, the following rocks are met with :

1. Commencing a little west of Riceville in descending the hill towards Bannister river, where the contact of the primary rocks with the middle secondary is beantifblly displayed, the last of the formation is a greenish argillaceous slate, dipping very steeply to the southeast.

2. A little lower in the hill, and resting on the edges of this slate, we see the beds of sandstone and red shale containing embedded fragments of Granite and other primary materials, dipping at a high angle to the northwest.

8. These continue until we come to strata of red shales and sand- stone of finer texture in the valley of the river.

4. We then have red and grey and bluish sandstones, the two former containing fragments of Felspar. These continue alternat- ing with little variation to near Ohalk Level, where the primary rooks again recur.

Crossing the tract near its northern extremity in the direction of the road by Reid's bridge to Charlotte 0. H., we meet with the fol- lowing strata :

1. On the western side, red and grey sandstone and conglomer- ate, the first predominating, the last forming irregular masses, con- sisting of large pebbles of Quartz, Mica slate, Granite, &c

2. Red shale and fine grained red sandstone.

Throughout all this tract, as formerly indicated, the dip of the strata is to the NW., the angle of inclination varying from point to point, being as much as 40 at the White Oak mountain, 80° at Mt. Airy, 40 at Pannil's mill, and in general lying between

The rocks of the middle secondary tracts of Prince Edward, Camberland and Buckingham counties, are for the most part identi- cal in character and contents with those of the more southern tract just illustrated, the chief points of difference between them being the greater prevalence in the former of greyish sandstones and car- bonaceous shales, containing impressions of shells and vegetables.

The following are the principal strata presented in crossing the tract north of the Appomattox river in a direction from Rainess tavern (Cumberland) towards Kurdsville :

1. Within one and a quarter mile of the tavern, we come upon the margin of the middle secondary rocks, here consisting chiefly of soft grey sandstone with some vegetable impressions, and a thin seam of impure carbonaceous matter exposed on the farm of William S. Walton.

2. Red and green shales and sandstones, hard and soft, appeai ing on the road in ledges for a distance of nearly two miles.

8. Yellowish and brown soft sandstones, and near Cook's mill a ledge of bluish slaty sandstone, containing a spiral univalve shell and the rhombic fish scale.

4. Yellowish and reddish shales and sandstones.

6. On the western margin of the formation nearly opposite Mrs. Hendricks dwelling, an extremely coarse conglomerate.

The conglomerate here referred to, which also makes its appear- ance one and a half miles west of Lacklands tavern on Mr. Harrions farm, and at other points in the same line, consists of large nearly angular fragments and large pehhles of primary rocks, cemented hy a coarse red shaly paste. At Mrs. Hendricks the embedded masses are chiefly the following: Felspathio Gneiss, Hornblende Slate, Epidote, Granite, Quartz, and Hornblende Gneiss. Among which is to be seen a nearly prismatic fragment 2 feet long by 8 inches wide, as well as many others closely approaching it in size. The huge dimensions of these fragments, esjtecially at the latter place, entitle the locality to rank among the geological curiosities of the state, and will not fail to excite the admiration of the observer when viewed as commemorating the mighty energy of the moving waters by which these enormous masses were torn away from their parent beds and transported to the ])08ition in which they are now found.

At numerous places in tins tract the shales and sandstones pre- sent thin seams of carbonaceous matter, bearing much resemblance to the dead coal often seen at the outcrop of a true coal seam, and at some points a small amount of impure bituminous coal has been found. The nearest approach to a seam of valuable extent is pre- sented on the land of Mr. Floumoy, situated near the southern ex- tremity of the small oval patch of middle secondary lying south of Prince Edward 0. H. Here the seam, as explored by a small shaft, is associated with brownish sandstones and shales, and is said to have measured nearly two feet in thickness.

In borings at Mortons mill and on the Bizarre estate, the former descending to the depth of two hundred, the latter of ninety feet, similar dark shales and brownish sandstones were encountered, en- closing several very thin seams of bituminous coal. At the former place the shales are impressed with the rhombic flsh scales, and the sandstones with vegetable stems and leaves, and these rocks, besides being slightly calcareous throughout, contain thin layers of impure limestone, a character, as formerly noticed, but rarely occurring in the southern portions of our middle secondary.

The thin seams of carbonaceous matter before referred to are found near the surface at col. Wilsons, Mr. Andersons and Mr. Walton's, the locality before noticed, and appear to be of very com- mon occurrence. Usually the material of tnese seams is a friable mixture of carbonaceous and earthy matter, seemingly intermediate between peat and coal, but in some places it has the character of a hard bluish black mass of rather porous texture, and inclining some- what to a columnar structure, bearing a strong resemblance to a compact mass of coke. The fact hereafter to be adverted to of the very ft'equent occurrence of dykes of igneons rock in this portion of the middle secondary tract, would favour the opinion that the mat- ter in question is but a modified form of the ordinary carbonaceous material caused by the high temperature of these rocks at the time of their intrusion among the middle secondary strata.

After a careful examination of varions ezpoenres in which these thin seams, as well as indications of coal are found in the tract in qaestton, it may be safely stated that no facts have been met with to warrant a more favourable opinion of the extent of coal it con- tains than that already expressed under a preceding head, and as on first appearances the simulated coal seams above described may prove an enticement to mining adventures, I feel it to be my duty to discourage all enterprises of the Icind as little likely to be attended with even partial success.

Ghaptbb 4.

Igneous Bocks oceurring in the Middle Secondary Traete.

At many points within the area covered by the sedimentary strata of this formation, we meet with beds of a hard, ponderous, dark coloured rock, remarkable for the rounded form in which it spontaneously separates when acted upon by the weather, as well as for the peculiar rusty coating and concentric structure of its ex- terior produced by the same cause. These beds, or rather dykes, far from constituting a part of the formation in which they occur, are due to totally different and for the most part later agencies. They are in fact the Trap or greenstone rocks of the geologist, and are igneous products, bearing close analogy to some of the results of volcanic action. Instead of lying conformably with the neigh- bouring strata, and therefore in the tracts of which I am now treat- ing, dipping to the northwest, they are found rieing through tibe beds of shales and sandstones that enclose them, forming in some cases a distinct ledge or wall, and thus severing completely the connection of the opposite portions of the same b. The strike or range too of these dykes, instead of being nearly NE. and SW., as is generally the case in the rocks around, pursues a course nearly at right angle with that direction, being for the most part about NW. and S£.

It would thus appear that subsequently to the deposition of the middle secondary strata through which they penetrate, these ie- ous materials have been forced in among them from beneath, filling, while in a molten state, the fissures created by the accompanying subterranean movements, and not unfreqnently entering between the layers of sedimentary rock, or pouring out and overspreading them at the top.

As might be expected, the effects of intense heat are often strik- ingly exhibited by the strata adjacent to these dykes, and as many curious examples of these effects are to be met with in our middle Hocondary region, it will not be deemed inappropriate to enumerate the more important of them in this place. They may bo thus briefly described :

1. A great induration of the sedimentary material, so that from a soft shale or sandstone, it is converted into a hard sonorous mass, yielding with difficulty to the hammer.

2. A greater or less obliteration by a partial fusion of the sepa- rate constituents of the rock, thus incorporating the Tarious parti- cles, and even fragments of considerable size, so completely as to render their recognition as orinally distinct, difficult and sometimes impossible.

3. A marked change of colour, owing to the chemical combina- tions induced.

4. The development of distinct crystalline matter, sometimes sparsely, sometimes abundantly, through the mass, so that what was formerly a mere aggregate of red sand and clay, becomes a bluish or greeni$h rock, studded with beautifully perfect crystals, pro- duced by the chemical union in definite proportions of certain in- gredients of the shale or sandstone originally only mingled in a loose mechanical way.

Without pausing to describe the various instances in which our middle secondai'y strata evince the modifying effects of adjacent Igneous rocks, I will content myself with citing a single but con- spicuous example.

This is to be seen on the James river a little above Warren. The middle secondary, whose eastern margin crosses the river from the hill below the ferry house to a point a short distance below Warren is here composed of alternating beds of red shale and coarse red conglomerate, containing rounaed fragments of Quartz, Epidote, Hornblende slate and other primary materials, ranging N. east, and therefore very obliquely to the stream, the harder of these beds, the conglomerate, is seen crossing it in numerous parallel ledges for a distance of several miles, thus foiming what is called Gold shy falls. About half a mile above the ferry house on the Buckingham side, the igneous rock presents itself in a bold hill, and is seen in broken ledges and enormous fragments stretching over to the opposite bank in a direction nearly perpendicular to that of the other rocks,- thus causing its appearancs there at a much greater distance up the stream. It is a very hard and rather coarse grained Trap, of a dark grey colour, arising from the mixture of a nearly black Hornblende, with a small proportion of Felspar. Where measured, its breadth is about 200 yards, but evidently dimuiishing as it extends north- west.

The shales and sandstones adjacent to this dyke on both sides of the river present various degrees of alteration, evidently depending upon the more or less refractory nature of their materials and their relative proximity to the dyke. On the sides of the hill, and there- fore almost in contact with the trap, their metamorphosis is so com- plete, that nothing short of the actual tracing of the gradually in- creasing change of structure, would justify the conviction that they are but modified conditions of the loose sedimentary rocks found at a little distance on either side. Masses of £pidotio rock, con- sisting of a hard bluish grey matrix with kernels of bright green crystalline Epidote, a similar rock in which the crystalline material is less ftilly developed, conglomerates in which the pebbles seem to have been almost melted together, red shales converted into a pur-

pie rock profaselj spotted with white kernels of crystalline matter, BO toogh and hard as scarcely to admit of being broken, are among the materials met with at this point, evincing the influence of the dyke. Indeed so entirely changed are many of these rocks that no trace of their sedimentary origin is retained, and judged of by hard specimens they would be pronounced to belong to tiie class of pri- mary rocks of undoubted igneous production, while in fact, to use a new term expressive of the conversion which they exemplify, they have only been primarized by the vast mass of igneous matter intruded among them.

The following descriptive list of specimens of these altered rocks will appropriately close the remarks upon this subject:

1. Fine grained red sandstone, indurated with kernels of a white mineral.

2. Purple rock, of great hardness, with crystalline specks. An altered shale.

8. Red sandstone much indurated with some Epidote.

4. Red sandstone with much Epidote.

5. Coarse sandstone much altered, apparently by a partial fusion, very hard.

6. Altered sandstone, with kernels of Epidote and micaceous iron in small scales.

7. Altered sandstone consisting of grains of Quartz dispersed through Epidote.

Section V.

Operations Of The Sub Vet In The Great Western Coal Es-

Qion,

Chapteb 1. General Sketch of the Structure and principal Sockt of the Region.

In conformity with the plan proposed in the beginning of the present report, the regions next claiming attention are,

First. The coal basins situated between the Front Ridge of the Alleghany in Hampshire and Hardy counties, and the ridge called Laurel Hill in Monongalia county.

Second, The wide tract lying west of Laurel HDl and its pro- longation south, and the Ohio river, and

Third. The district watered by the Great Eanawha and its tributaries, extending from the irregular eastern escarpment of the formations associated with the coal, as far west as the Ohio.

Of the first of these regions I propose presenting a somewhat detailed description, but of the two others it would be premature, in the present stage of our investigations, to attempt any systematic account, and in regard to these therefore I shall do little more than give a brief sketch of the progress of our investigations, and present

some important local iUnstrations adapted to shew the nature and bearing of certain interesting results already attained.

As the widely extended surface of these regions, and indeed of the whole of that portion of the state lying west and north of the eastern escarpment of the rocks immediately associated with the coal, comprises groups of strata, fur the most part superior in geo- logical position to the highest member of the Appalachian series described in my two last reports under the title of formation XL, it will be. useful, before entering into particulars as regards the geo- logical features of any portion of the wide region under considera- tion, to describe, in a general way, the principal groups of strata by which it is overspread, as well as the more prominent facts relating to its structure, developed in the prolonged axes, occupying a large portion of its surface.

Bearing in mind the descriptions given in former reports of the numerous, successive and generally abrupt undulations exhibited by the strata in almost every part of our Appalachian region, and the prolonged lines of parallel anticlinal and synclinal mountains and valleys, thus disposed in alternating arrangement upon its surface, we are not surprised at finding similar variations in the positions of the strata continued for some distance beyond tlie margin of the region in which the higher and more western groups of rocks appear.

These anticlinal axes met with in our great western coal region, preserving a paraUel direction with those of the Appalachian belt, give rise to ranges of mountains less elevated above the general level of the surrounding region, and broader and less abrupt in their declivity than the ridges formed by the more steeply inclined strata of the Appalachian portion of the state. Yet, as might naturally be anticipated, along the summit of these broad mountains, the mantle of rocks appertaining to the coal formation, once evidently continuous in its extension over the inferior strata, has been more or less removed ; and thus over their undulating tops and in their profound ravines and river gorges, the upper groups of strata be- longing to the Appalachian series, are not unfrequently deeply and extensively exposed. The destructive rush of waters, whose de- nuding power is so clearly attested by the removed summits and gashed sides of so many of these broad ridges would seem, after tearing away the stouter materials above, to have met with far less resistance from the soft shales and sandstones, forming the interior mass. Hence would appear to have originated the deep valleys and abrupt hills by which the space included between the flanks of these ridges is so generally characterized, and hence the deeply scooped channels of those streams, which are permitted, not merely to pass through, but to meander for great distances along the central line of the axis and in the very heart of the mountain, whoso interior structure they thus contribute to disclose.

Of the topographical and geological features here described, nu- merous exemplificatioos are met with in that portion of the great western coal region nearest to the western margin of the Appala duaa belt, more especially towards the northern limits of the state,

while over the wide districts lying still farther west, the few low andulations which occur, ultimately become lost in the gentle and almost imperceptible inclination of the strata towards the valley of the Ohio. Hence throoghont this more western portion of the area occupied by the strata appertaining to the coal, even the uppermost of the Appalachian rocks is no longer to be met with any wbere upon the surface or in the deepest natural or artificial exposures that exist. The rocks belonging to the principal coal measures, in their turn also become buried as we approach the Ohio in the region of Parkersburg and Point Pleasant, giving place upon the surface to shales and slates and sandstones, either destitute of ooal or contain ing it in thin and variable beds. These gently sloping strata thus gradually depressed, again rise to the surface as we proceed still fur- ther to the west, thus bringing into view, over a wide and affluent belt of country in the neighbouring state of Ohio, the counterparts of the lost coal seams and their associated beds of sandstones, slates, shales, iron ores and limestones in an order the reverse of that in which they had been seen to disappear in Virginia, some distance east of the Ohio.

As necessary to the general picture of this wide spread series of rocks, it may be added that beyond this belt of productive ooal measures in Ohio, as we descend to the valley of the 8oioto,.we come in view of a group of underlying east-dipping sandstones, slates and limestone, corresponding to our upper Appalachian forma- tions, so that comprehending in one wide view the whole series of strata, comprising and lying at no great distance beneath the coal rocks of this wide region, and leaving out of consideration the un- dulations previously alluded to as occurring towards the eastern margin of the tract, we are presented with the imposing scene of a TMt synclinal trough or basin spreading from the eastern escarpment of the coal rocks in Virginia, entirely across the western portion of the state and the eastern half of Ohio, and terminating there in a similar escarpment in which the rocks are seen inclining towards the east to meet their counterparts dipping in an opposite direction in Virginia. It is a little westwards of the centre or lowest line of this enormous basin, that the Ohio river pursues its course for most of the distance in which it forms the western boundary of our state. But another feature is yet to be introduced to complete the general outline of this interesting region. The eastern and western mar- gins of this basin, though nearly parallel about midway of its length, gradually approach each other as they extend towards the north, and thus bending round, the former in Pennsylvania, the latter in Ohio, at length actually coalesce and form the head or northern ter- mination of the trough. As a result of this configuration it will at once be seen that along this northern boundary of the basin, the coal rocks must have an inclination towards the south or in the direction of the length of the vast trough, while the Appalachian strata underlying them beneath this northern escarpment will be seen dipping beneath the basin in a corresponding direction.

Fortunately for the resources of the valuable though small tract

indadiiig the three comities lying hetween PeniiBjlvania and Ohio, this northern termination of the trough takes place at no great dis- tance north of where oar territory begins. So that the Ohio in its coarse along the western margin of that tract intersects the south- erly dipping strata in a direction highly favoarable for the develop- ment of their rich mineral contents, and exposes along the Virginia as well as the Ohio shore, nearly ail the seams of coal, and beds of limestone and other valuable materials, required to complete the series of strata appertaining to the vast coal basin through which it flows.

From this general outline of the great western cool field of which Virginia possesses so large a share, it will at once be seen, that leaving out of view the numerous important undulations of the strata before referred to, the higher rocks in the series present themselves successively, dipping beneath the surface as we recede from the margin of the basin towards its middle, from whatever point of this margin we may take our departure. Each stratum of the vast series of the coal measures may in truth be regarded as an immense oblong bowl or trough whose longer diameter has a direc- tion nearly N£. and SW., terminating at the northern end, near the Ohio and Pennsylvania line, and gradually widening in a somewhat oval form as it passes through Virginia and Ohio. Near its widest part, it is obvious, the Virginia and Ohio portions of the margin would be parallel to each other and to the longer diameter, and would therefore have a direction from NE. to 8W., but in the prog- ress of its expansion, all the directions between that of its north- ern end and the one just specified would successively obtain ; so that following it along the eastern margin, we should have it SE. and NW., S. and N., 8W. and NE., and perhaps within the limits of Virginia, approaching Kentucky and Tennessee, WSW. and ENE. We may therefore regard a series of such bowls, similar in form and fitting the one within the other, as giving a general representa- tion of the stratification of the entire region we are considering, neglecting for the present the irregularities occasioned by the undu- lations in the neighbourhood of the eastern margin.

Bearing in mind this inelegant but perhaps not useless illustra- tion, it will at once appear that a river entering the margin of the basin and flowing entirely through it, will penetrate in succession each of the inner bowl-shaped strata on the one side, and then pass- ing across the innermost, and therefore the uppermost of them all, will again penetrate the same beds, but in an inverted order — and if, as in the case of the Ohio, we suppose it to enter near one of the extremities of the oblong trough, and to flow nearly along but a lit- tle west of its central line, we shall have exposures of all the strata from the northern margin to the highest bed of the series, those only excepted, which forming the very innermost and uppermost of the concentric strata, present their western margins to the east of the valley of the river. These, as is really the fact, would be found capping the hills at some distance eastward of the river, and pre- senting hot) I their eastern and western margins on the Virginia

side. To complete the appHoation of this rnde analogy to that por- tion of the great trough of coal-bearing strata throngh which the Ohio flows, the varjing developments of the rocks caused by its fre- quent and important changes of direction, claim also to be consid- ered. If while flowing through the highest or innermost of the strata accessible in its general course, and thus pursuing a direction nearly from N£. to SW., it should be diverted from this line so as to take a direction towards the west or NW., it is obvious that this would lead it away from the inner and higher strata, and carry it across some of the subjacent beds, while a change in the opposite direction would convey it into still higher strata lying to the east, and if continued for a sufficient distance, might carry it through them to pass into the eastern or Virginia sections of the lower strata. It is thus that the river in that part of its course extending from near the NW. corner of Tyler county to the bend a little above Marietta, flowing nearly in the central line of the trough, exposes only the upper strata, but bending towards the N W. as it approaches Marietta, it displays strata a little lower, and thence pursuing a direction nearlv parallel with that firrtt mentioned, it passes Parkers- burg in a line several miles west of what may be regarded as the axis of the trough, still continuing to display nearly the same rocks as are met with at Marietta, until by another and more important flexure to the NW. below Letarts falls, it plunges more deeply still into the strata west of the middle of the trough, bringing to light in a position sufficiently elevated above the river to be productively mined, the important coal seam wrought on the Ohio side, and known as Pomeroy's seam. Oontinning with numerous flexures its general southwestern course as far as Burlington, and keeping very nearly in the snme rocks, the coal of whicit is again exposed below Gallipolis, it bends around to take a direction bearing it across the western portion of the basin, after which traversing in succession lower and lower strata of the coal measures, and presenting a noble development of rich coal seams and iron ores on the Ohio and Ken- tucky sides, it emerges from the basin near Portsmouth and pursues its way through the Appalachian strata lying to the west.

I have thus, at the risk of tediousness and repetition, endeavoured in a familiar manner to describe the general features of our great western coal region, in the hope that the more important relations of its strata as to direction and position may be clearly conceived, and that thus erroneous views as regards the general extension of the more important coal seams may be no longer entertained— and I have been thus minute in exemplifying the configuration of the strata included in this vast basin, and the various modes in which they are exposed by the noble river which pursues its way along and through them, from a belief that some generid plan or pattern elucidating the great features of structure thus particularly dwelt upon would aid the reader in comprehending the more local descrip- tions which are to follow.

As an important preliminary to the details about to be presented in regard to the structure and contents of a portion of the wide area

above referred to, I now proceed to ve a brief aooonnt of the more important groups of strata found within its limits. And since, as already stated, some of the upper portions of the Appalachian series are repeatedly brought to light within the confines of this region near the northern border of tlie state, and as thej moreover form the basis on which the coal rocks are seen to rest along nearly the whole of the eastern margin of the great coal field, it will be foand useful briefly to advert to the peculiar features by which they are distinguished where adjacent to the coal rocks in both of these positions.

Formation X

Of the various axes hereafter to be described, occurring within the eastern margin of the great area of coal rocks, but one has yet been found south of the Maryland and Pennsylvania lines, and north of the deep gorge-like valley of the Dry fork of Cheat river, in which the formation here referred to has been sufficiently elevated to be brought distinctly into view, while in both of the states just men- tion not only this but formations IX. and YIII. still lower in the AppaUchian series, are developed in considerable extent by the ex- pansion of some of the Virginia axes as they are prolonged towards the northeast. Of the existence of the formation in question, in the middle and southern parts of Randolph county, no opinion can as yet be formed, as our explorations in the northern part of the coal region have not been prolonged to any great distance south of the fork of the Cheat river before mentioned, which traverses the county in a NW. direction. Along this stream, which flows in a profound transverse trench across several axes hereafter to be described, not only this but the two subjacent formations IX. and YIII. are in part exposed. But minute examinations still further to the southwest have clearly shown that in none of the axes there presented has this formation been elevated to the surface. Indeed, throughout this part of the eastern margin of the coal region, the undulations are extremely gentle though of great breadth, and merely sufficient, where aided by the deep trenching or denudation, here giving the wildest irregularity to the outline of the eastern escarpment of the coal rock, to briog into view the formation lying immediately beneath (XL), and between them and that of which I am now speaking.

Along the eastern slope of the Alleghany front rid in the northern part of the state, and its continuation in the lofty range separating Pendleton from Randolph county, the rocks of this forma- tion may be seen generally about midway up the mountain. They here consist of coarse white and reddish sandstones, often contain- ing pebbles, greenish and reddish micaceous sandstones of a slabby structure, and conglomerates consisting of white pebbles embedded in a dark brown or a greenish paste. At many points the coarser sandstones, as well as the micaceous fine grained rocks, are rich in impressions of vegetable stems and leaves, usually converted into bituminous coal, and in some places within these limits a very thin

seain of impnre coal is interposed, thongh oontinned only for a short distance.

In Pocahontas and Greenhrier counties this formation thrown a little west of its original direction hy the rising of new axes in the Appalachian district, is seen skirting the Greenbrier river to near the bridge a few miles east of Lewisburg, presenting in general the same characters as above described, bnt including at varioas points, as for instance on tbe river west of Huntersville, a conglomerate of remarkable coarseness, in which whitish pebbles, sometimes two inches in diameter, are embedded in a brownish and greenish paste. As followed in this direction, its thickness, thongh flactuating, is very much augmented, as will appear from the fact that while on the Potomac below Westernport, where the river makes a trans- verse section of the Dan mountain or Alleghany front ridge, it measures only about 200 feet across in a direction perpendicular to its lower and upper bounding plains, in the vicinity of Lewisburg its width is about 800 feet. It may also be remarked, that with this increased development of the formation thus locally presented, we find, as has been noticed in numerous other cases in regard to the same group of rocks, a corresponding development of the thin seam of coal included in it, as occurs in the vicinity of Lewisburg, though here as in most other parts of the formation the amount and quality of the coal are not such as to repay exploration, except for imme- diate neighbourhood purposes, and indeed but rarely even for these. West of the exposures near the Greenbrier river, it is not again brought up, excepting over a narrow space in the low anticlinal hill called Brushy ridge, which separates the levels from the valley of Sinking creek. It is here flanked on both sides by the overlying limestone of the formation next to be noticed.

Of the character of formation X. as presented in several of the axes in the northern part of the state, particular mention will be made in treating of that district under a subsequent head.

Formation XL

The group of shales, sandstones and limestones included in tliis formation constitutes the upper member of the Appalachian series of rocks as systematically described in my two preceding reports. Rest- ing upon the upper surface of X. they are well disclosed along tiie front ridge of the Alleghany in Hampshire and Hardy counties, occu- pying the higher portion of its eastern slope, and dipping with a moderate inclination towards the northwest, so to pass beneath the strata of the coal basins lying in that direction.

Further towards the south, the calcareous as well as the other parts of this formation became more widely developed, owing in part to an increased thickness in the rocks, and in part to the influence of several axes west of the front ridge, which {)y repeated turns re- tain the formation longer at the surface. Entering Pocahontas county near the head waters of the Greenbrier river, the lower strata are seen skirting the river generally near its western margin, the wind-

inga of the stream oanring it Blteniately into the rocks of X. and of XI. Tlie inoreasiDg thickness of the formation, together with the great flattening of its dip, as wa trace it south, cause it to over- spread a wide area in Greenbrier and Uonroe oonotiea, thronghoat a large part of which the calcHreoos portion of tlie formation is seen imparting to the snrface the undulating outline aod the productive soil uanall]' met with in limestone regions.

Still further towards the southwest we find it occnpjing the eastern slope of the Blue Stone iiioontain, and with a ver; gentle inclination towards the northwest, dipping beneath the coal rooke of the Great Flat I'op mountain, which with a gentle slope in the SAme direction spread continuously thence towards tbe vallcj of the

Ohio.

In Tazewell and Bussell. wherever met with, its general oharao- ter and position are found to be unchanged, but the long lines of dis- location bj which the BOothwestero portion of our state is so won- derfellf marked, in numerous instances conceal this and several of the a<Uacent Appalachian formations, pressing up to the verj margin of the ooal rocks, strata far lower in the series, and even crashing these rocks and their contained seams of coal, folding them together and taming them over into inverted dips.

Having in taj two preceding reports described somewhat at length tbe varioDS strata included in the formation now in view, it will be nnnecessary to enter into limilar details at present. I will therefore content mjaelf with stating, as characteristic of tbe for- matJoD wherever met with in Virginia, the ooourrence of beds of limestone near tbe bottom, tbe prevalence of red and een soft de- composing shales above, and of brownish and greenish sandstones near the top. I may also add the ver; common occurrence of small rounded concentric grains the size of mustard shot, or a little less or greater in certain bands of the limestone, and tbe Ter7 fre-

aaent presence of a thin seam of ooal, or of bitnminons slate, where lis formation adjoins the overlying conglomerate or sandstone of XII.

To display the nature and relative extent of the several atrate fbrming this group, as exposed at points verj remote from each other, and thns to lllnstrate the remarkable expansion especiallj of the oal- careons portion of tbe formation as developed west of the Greenbrier river in Pocahontas and Greenbrier counties, I annex tbe following details of measurements made tn tbe course of onr elorations dur- ing tbe past season, tbe one along the margin of the Potomac below Westernport, where the river intersects these strata nearl; at right angles, the other from near tbe mouth of Stamping creek in Poca- hontas ooant7 np the slope of the Greenbrier moontain, where, in the form of a lofty eaoarpment of nearly semicircular form, it over- looks the beantiful limestone valley of the Little Levels.

Thickness and character of the several strata of formaldon XI. on the Potomac below Westernport ;

Oommonoing with the highest group of strata which are st-en extending nearly to tlie top of tlie lofty nlll, whose capping beds of

sandstone have reoeived the name of the Horse rooks, and proceed- ing in the order of their position to the several underlying beds as far as the upper limits of the next inferior formation (X.), we have the following results :

1. A mass of sandstones and crumbling shales of a deep red colour, with occasional bands of a greenish tint. Towards the top tlic beds are more siliceous and less deeply tinged, but lower down they assume the soft shaly character and the peculiar rich red colouring characteristic of this part of the formation. Thick- ness, 650 ft.

2. A bed of limestone, the highest rock of this descrip- tion in the group. It contains fossils, and is conglom- eritic, consisting of pebbles of limestone cemented

by a mixed calcareous and shaly paste, 4 6

8. Light grey freestone, slightly calcareous, 3 7

4. Red shales, generally argillaceous and crumbling,. . 97 8

5. Red and grey variegated sandstone of a slabby structure 6 2

6. Red argillaceous shales, 78 6

7. Siliceous limestone with oolitic bands containing at bottom 18 inches of pure light grey limestone, 46 7

8. Red shale and sandstone, with bands of limestone, . 15 5

9. Siliceous limestone remarkable for its diagonal lam- ination, and for the coarse grains of sand stand- ing in relief on its weathered surfaces. This latter character, caused by the removal of the calcareous matter from around the grains, is so striking, that though often a pretty good limestone, so far as ap- plicable to the making of lime, it presents the aspect of a light grey and coarse freestone, and might readily be mistaken for such. It is however an in- ferior rock to (7), 10 4

10. Red limestone, rather siliceous generally, but in

parts of pretty fine grain, 6 0

11. Pinkish marble, 1 0

Total thickness 918 ft. 9 in.

Thickness of calcareous rocks about, 80 0

Small as is the proportion of the calcareous rocks to the other strata displayed in this locality, it is found still to diminish as we proceed north, until as stated by my brother, professor H. D. Rog- ers, in the interior of Pennsylvania, at some points, the limestone bands are entirely wanting. The following details will serve to shew how greatly these limestones are augmented in thickness as the formation extends towards the southwest :

Thickness and character of the strata of formation XF., as meas- ured from the mouth of Stamping creek to the top of the Greenbrier mountain, Pocahontas county :

1, SandstoDCB and sliale tbe former predominating to- waniB the tp, the latter lower down. The general coloDF of the shales 'w a rich brownish red with ocot' sional interpolated greenJBh bands. Texture of the ahales cruinbl;, oompnsitioa chiefly argilloceoua, with a little cnloareouB matter. The more siliceoas rocks above are red and pej, dightlj micaoeong, and inclnd- ing shol; baods. Tbej are reodilj' divided into slabs,

and are rarelj of a coarse texture. Thickness, 1280 feeL

2. Blae and grej limestone, with argillaceoos sbolj bands occasional); interposed. Some of the strata wonder- ttillj rich in fossnls. Near the top of the limestone occurs a flinty or chertj lajer, also fall of fossils, 623

8. Red argillaceoDS cromblj shales. SO

Total thickness 2132 feet.

On CDinparing the two measnremeatg thns giveo in detail, we see that not onl; has the entire tbiokness of tbe formation augmented in extending tonards tbe southwest, but the relative unount of lime- stone has increased in a still higher proportion, tbe former having expanded to about 2) and the latter to 10 times its thickness, as seen npon tbe Potomac.

The interesting results of this change in the character and extent of this formation are well seen in the richly prodattive surface of the Little and Great Levels, the valle; of Sinking creek, and the wide limestone region of Monroe count;, which are geologically but the ooanterparts of the nujTOW hand uf limestones and calcareona shales lying along the eastern declivity uf the front ridge of the Alleghanj in the northern portion of the state.

As might be expected, nrneh variety is displnjed in the compo- siljon and character of the different hands of limestone belonging to this formation. Nor is there much constancy iu the seme band as exposed in different localities, as will appeor from the analyses given towards the close of the present report. Wliile some of these rocks are remarkably pure limestones, burning Into a white lime of the finest texture, others contain a large admixture of carbonate of niag- nesin as well as of silica, and often also oxide of iron ; and by trials re- cently made, fumi.ih a waler cement of good quality. A large num- ber of similar analyses are yet to be made in regard to these rocks as exposed in tbe axes of the Cheat, Laurel Hill, and other ridgea within the limits of the great coal region, as well as over the wide area of calcareous rocks developeil in this formation further south.

lT<m orci are of frequent occurrence near tbe upper limit of the formation, more especially where it is met with in the axes before spoken of, and often exists in such amonnt. and of a quality so rich and easily wrought, as to poMcss a high degree of economical im- portance. Of the composition of these ores, which are usually pro- to-carbonstes of iron, some examples will be given hereafter, and & large number of further details will he gathered in the progress of onr chemical investigations.

Formatum XIL

HaTing thas, in some detail, described the varioas strata b<e- longing to the two upper formations of the Appalachian series, more particularly with the view of affording the means of identifying them as they are presented within the limits of onr great coal region, and in the hope also of rendering the description of a portion of that region hereafter to be given, dearly intelligible to the reader, I proceed now to treat of we first of the series of rocks immedi- ately associated with the coal, and upon which repose all the slates, sandstones, limestones, and coal seams comprehended under the denomination of the coal rocks.

This formation, strongly contrasted in its general aspect and corapodtion with the preceding, which lies immediately beneath, consists of a group of whitish or light grey sandstones, generally of a coarse texture, and comprising heavy beds of conglomerate, usually conspicuous for the white polished round pebbles of which it is maiidy composed. The loose and open texture of these coarser rocks, causing them to crumble by long exposure to the weatlier, occasions the disengagement of the pebbles, which are thus seen profusdy strewed over the surface in many places where this forma- tion occurs, becoming in fact a useful geological land-mark where the rock itself is concealed from view.

This beautiful white gravel is met with in great abundance, ac- companying the massive strata of the conglomerate, high up on the eastern front ridge west of the upper termination of formation XI.

The same coarse rock, with its attendant pebbles, is found in a similar geological position on the Backbone of Alleghany, on the Cheat mountain and Laurel Hill, as well as several other minor ridges. It is also well displayed on the summit of the Big Sewell and various knobs and ridges of the adjacent region, and forms the nearly level capping of the Blue Stone mountain and its continua- tion further to the southwest. Every where along the margin of the great coal region, this formation may be seen, marking the transition from the upper member of the Appalachian scries of rocks to the widely expanded groups of strata witn which the coal seams are associated.

It is not however to be inferred that at all points it displays the same conspicuous conglomeritic structure, or is developed to the same thickness, for in both these particulars it presents frequent and important fluctuations, passing from a mere mass of large rounded pebbles cemented by siuceous matter, chiefly at their points of con- tact, to a conglomerate of shot-like gravel, and thence to a coarse, and in some cases, to a fine sandstone of even and compact texture, and in thickness varying from a thousand, and perhaps more, to a hundred, or even less thui a hundred feet.

Nor in all cases does it throughout maintain the character of a purely siliceous rock, for instances occur in which bands of slaty sandstone, and even bituminous slate, accompanied by one or more seams of coal, are included between the coarser and more massive

strata of the formation. Tet with all these variations, the general characters of the groap as ahore described, are safficiently definite to enable liie practised observer to recognize it when it appears, and its features asnallj are so well marked that a glance is sufficient for this purpose.

It will readilj be seen, from what was before stated in regard to the general arrangement of the strata, in and adjoining the coal re- gion, that the upper position, geologically, of this or anj other group of rocks, does not necessarily imply an actually greater elevation above the general level of the region, compared with rocks geologi- cally inferior. The positions as to height of the various rocks of the great basin, or of any of the axes within its confines, is greatly determined by the extent to which they have resisted, or yielded to the denuding agencies, to which, as rmerly illustrated, they have been every where more or less exposed. On this account the forma- tion of which I am speaking is often absent for great distances along the top of an anticlinal mountain, while low down upon the flanks of the ridge it may be seen in enormous blocks, or thick continuous strata dipping away in opposite directions from the enclosed and underlying beds of XL, while the latter rising in undulating hills along the intervening space, tower far above the strata which once extended as a connected covering entirely over the mountain from side to side.

It will at once be inferred from what has now been said as re- gards the geological position and usual characters of this formation, that as a general rule, explorations in pursuit of coal should be di- rected to the series of strata, lying abate it in geological position, and that where the outcrop or margin of the conglomerate may be clearly traced, we are to be governed by the direction in which the strata dip, in selecting the line most suitable for our examinations. Where for example these strata are seen inclining downwards towards the KW., we would take our departure from the margin of the basin marked out by the beds of conglomerate, and travelling in the direction of the dip, or towards the NW., we would enter upon the upper and coal bearing strata lying within, and thus successively encounter the coal seams and their accompanying rooks in the or- der of their superposition. It should be observed, however, that in applying this rule it is of course presumed that the route thus pur- sued is along a line which, if not horizontal, descends towards the centre of the basin at a less angle than the dip of the conglomerate and overlying rocks, for otherwise we might continue upon one or other of these beds throughout nearly the whole of our course; or, if following a line of very deep denudation, might penetrate below the conglomerate into the formation which lies beneath.

The remarkable expansion and diversified character assumed by this formation for some distance within the margin of our great coal field in the western parts of Pocahontas and Greenbrier counties, has caused it there to overspread a wide area, and to include along with the usual beds of conglomerate numerous beds of slate and sandstone, varying in hue and texture, together with seams of coal of sufficient

magnitude and pnrity to be esteemed worthy' of exploration. Of the exact limits of this remarkably diversified group of strata, it is as yet impossible to speak with confidence, the undulating direc- tions of the beds and the topographical peculiarities of the country having presented difficulties in the way of a precise solution of this problem, which can only be removed by further examination. This much, for the present, may be stated, that the coarse and partially conglomeritic sandstone composing the celebrated cliffs of New river, skirting that stream on both sides for some distance in the form of lofty mural precipices, and prolonged with a northwesterly dip, so as to constitute the wide sheet of nearly level strata over which the Kanawha is precipitated at the falls, is to be regarded as occupying the same place geologically with the similar strata fonn- ing the general margin of the region occupied by the coal bearing strata ; and in confirmation of this view it may be added, that tlte series of sandstones, slates and coal seams so admirably exposed in the lofty hills extending along both sides of the Kanawha to some distance west of Charleston, and which have been asrertained to overlie this conglomeritic rock according to a nearly invaiiable order, are in all important features analogous to the group of coal bearing strata elsewhere found resting next above formation XII. It would therefore appear probable that a part, if not all the coal seams as- sociated with the rocks of the Big Sew ell mountain appertain to a lower group of coal rocks, forming a portion of the formation of which I am treating, here widely expanded and wonderfully diver- sified in its characters. But as already stated, further investigation is required to determine with exactness the true boundaries of this formation, and therefore the true relations of the various rocks in question.

Formation XIIL

Under this head it is deemed convenient for the present to in- clude the whole of that diversified series of rocks comprising sand- stones, fine, coarse and conglomeritic, slates, shales, limestones, and seams of coal, which occupy nearly the whole of the wide area lying beyond or west of the formation just described.

In remarking upon this formation no attempt will be made to give a minute account of the more important groups of strata which it comprises, as such a description, even though it were partial, would mvolve an amount of details incompatible with the design of the annual reports, and as moreover much further examination is requisite in nearly all portions of our great coal region to enable me to present its economical and geological characteristics in the ample form necessary to render a description of them satisfactory and use- ful. I shall therefore confine my observations under this head to a general account of the formation as presented at different and re- mote parts of the region, with the view of illustrating some of the more important modifications by which it is affected in extending ftom tract to tract, as well as of indicating certain important land- marks among the very numerous and variable strata of which it is

composed, adapted to famish ns with valaable aid in assigning their true limits to the chief subdivisions of the formation, as well as in condacting oar explorations for practical purposes on sure principles and to oseful results.

Throughout the larger part of the entire thickness of this forma- tion, commencing at its lower surface, or where it rests upon No. XII., the rocks are cbieflj of a decidedly siliceous character, consist- ing of sandstones of various textures, from the finest grit to coarse conglomerates, generallj containing some, and often a large amount of mica, presenting considerable variety of hue, comprehending blended tints of grej, light brown, and greyish green, and in some cases almost pure white. Associated with these are layers of lime- stone for the most part of a dull bluish grey, but sometimes of a dark brown and nearly black tint, and generally shewing an ochreous as- pect on the weathered surfaces. These beds, as met with in Vir- ginia, are rarely more than a few feet in thickness, varying in this respect from point to point, and not unfroquently losing themselves by gradual transition into slate or iron ore, or sandstone. Numer- ous beds of slate also interpose themselves between the siliceous rocks, presenting for the most part a dark brown or nearly black, and an ochreous greenish colour. It is with these, particularly the former, that the coal seams are in general immediately associated. The bands of iron ore also usually occur in or adjoining them, as well as contiguons to the layers of limestone.

Towards its upper limits rocks of a less arenaceous character pre- dominate. The sandstones which still occur in heavy beds are of a softer and in general finer composition, and the slates assume the form of argillaceous shales of a crumbling texture and deep reddish colour, alternating occasionally with green and ochreous tmts, pre- senting a striking general resemblance to the shales of IX. and XT. of the Appalachian series. In this part of the foimation the cal- careous beds in seneral occupy a far greater thickness than below, imparting a richly productive character to the region over which in some portions of the great coal tract they are widely spread out. Calcareous matter is also present in considerable amount in the as- sociated shaly strata, which are therefore in general marked by a productive soil

Near the highest strata of the formation little or no coal is met with, but among the beds next beneath occurs one and in some cases two coal seams of great value, as well on account of the usu- ally good Quality as the abundance and continuity of the ooaL It is in this geological position that we meet with the celebrated Pitts- burg coal in Pennsylvania, and as hereafter will be shewn, the valuable seam explored in the hills at Wheeling, Morgan town, Clarksburg, and nnmerous intervening points. The two principal seams in the Potomac basin, to be noticed in the sequel, are evident- ly referrible to the same position.

Besides the general differences here noticed in the nature and aspect of the materials predominating respectively towards the lower and upper portions of the formation, important modifications in the

composition and degree of development of its several sabdivisions are seen to occur as we trace them from one portion of the great basin to the other, some of which, from their economical importance, as weU as their general occurrence, merit a brief notice in the pres- ent sketch of the formation.

One of these changes is exhibited in the increased coarseness of the materials forming the arenaceons strata of the lower parts of the formation as traced from the northern limits of the state to tlie val- ley of the Great Kanawha, and at the same time the greater pre- ponderance of the sandstone strata occasioned by their increasing thickness in that direction. This fact is well exemplified in compar- ing the rocks lying between the western base of Laurel H ill in Monongalia county, and their counterparts along the Kanawha, from the falls as far down as Charleston. The comparatively small amount of slaty strata along the latter section, though fortunately unaccompanied by any diminution in the thickness or deterioration in the quality of the coal seams there so admirably exposed for long distances continuously in the river hills, would appear to connect itself with the attenuated width of the bands of iron ore occurring among these slates, and therefore would seem to give a general con- firmation to the conclusion derived from our observations thus far, that these ores are much less abundant in that than in some of the more northern divisions of the coal field.

In the calcareous strata, especially those appertaining to the higher subdivisions of the formation, an equally marked idteration is exhibited. As followed in a southwesterly direction from the Pennsylvania line, these beds spreading widely over the tracts lying to the west of the Monongahela, are seen gradually beoominff thinner by the interposition of strata of variegated calcareous slides, until over the western parts of Harrison, Lewis and Kanawha, as well as nearly all of Wood, Mason, Jackson and Cabell counties, a small and variable remnant of these rocks is met with, forming thin bands among these shales, which have now almost entirely usurped their place. As a striking illustration of the remarkable change here noticed, reference may be made to the expanded thickness of the limestone strata in the hills bordering the Ohio, in the vicinity of Wheeling, where these rocks appear to have attained their greatest developement as compared with the thin and variable seams of cal- careous rock encountered in the region between Charleston and Parkersburg on the one hand, and Guyandotte on the other. Of the real extent and frequency of these small bands, further observations are requisite to enable me to speak with confidence ; the region in which they are met with having, as yet, been but partially explored. They will, however, receive that attention which, from their local imjmrtance in connection with ordinary and agricultural uses, they are believed to claim.

From what has now been said in the way of a general sketch of the prevailing characters exhibited in the lower and upper p<rtions of this formation, as well as the interesting modifications occurring in each as developed in distant portions of the coal region, it must

be apparent that the whole formation admits of being conveniently diTided into two great groups of strata, each comprising sandstones, dates, shales, limestones and seams of coid, bat yet snmoiently dis- tinguished from the other by the predominating featares above de- scribed. Adopting snch a division therefore as condnoing to greater clearness and simplicity in the economical as well as geological Ulastrations hereafter to be given, I shall for the present desiiate them respectively by the titles of the lower eoal$erieBBnd the tipper eoal$erie$.

It cannot fail to be remarked, that in the perplexing and labori- ons investigatioDS which are so often undertaken with the view of discovering or tracing the coal seams or other strata of the region nnder consideration, great assistance wonld be derived from the knowledge of some one bed or stratum, whose continuity over wide areas and constancy in position with regard to the other rocks, had been satisfsctorily demonstrated. For in a region so broken, as is much of that of which I speak, and in which the strata present fre- quent though gentle undulations of dip, and often bear a strong re- semblance to each other, the attempt at tracing them by an imper- fect system of levelling, aided by rude computations of the angle of dip, is Hkely in many esses to lesd to results not only erroneous, but prejudicisl to individuals and the public.

It is OQ this account therefore that in the course of our opera- tions in this region, as thus far carried forward, I have made it a leading object iu the first place to acquire the necesssry data for drawing, with some degree of accuracy, wherever possible, the line of separation between the lower and upper coal series, as well as for tracing the more valuable coal seams or other useful deposits, by reference to some standard bed or stratum whose persistency over wide aress has first been satisfactorily established.

Our observations thus far in regard to the rocks towards the middle of the formation, would seem to shew that, between the upper and lower series, there is generally interposed a greater thick- ness of strata, barren of workable seams of coal, than either above or below, but of the constancy of this fact it is impossible to speak until I have completed a number of measurements proposed to be made at various points in the coal region, nor would a feature of this kind, unless exceedingly distinct, be of much avail to those who are interested in explorations for coal. Some mark more definite in its nature should, if possible, be determined. Such an one, I am happy to say, has been found to exist in that portion of the coal field which is traversed by the Kanawha river, and though not dis- covered until some time after the commencement of our operations during the Isst season, it has already enabled us to obtain a clear knowledge of all the general, and most of the minute featares of that highly interesting and valuable part of the basin.

The land-mark to which I here allude, and which was first recog- nized, and afterwards diligently traced by my brother prof. J. B. Rogers, consists of a band of black or bluish black siliceous rock, approaching the character of a fiint or homstone, which is found in

the bills at the height of Beveral hnndred feet above the river near the falls, and which, acoornpanviDg the subjacent strata in their va- rious undulations, and their nltimate steady western dip as they extend down the river, is seen to disappear below the water level at the Elk river shoals.

This stratam, from its striking pecaliaritj of character, and its constancy of geological position, furnishes a standard line with which to compare the rocks and coal seams both above and beneath, and may be regarded iu this region as clearly defining the boundary be- tween the upper and lower series. As will be seen hereafter, throughout the tract extending from the falls to the point at which the flint coraes down to the river level, no seams of coal, but such as are local and of insignificant extent, occur in the hills above this stratum, but as we proceed towards the west, and thus in virtue of the westerly dip of the rock, pass successively into strata higher in the geological order, we meet with one or more coal seams asso- ciated with the shaly rocks already noticed as predominating in the upper series.

The discovery of this, or some equivalent band, in other parts of the coal region, is a result peatly to be desired, and will, it is thought, be attained during the operations of the coming season. Towards this, as well as other interesting determinations, more especially relating to that portion of the region which lies adjacent to Pennsylvania, the minute researches now making in the corre- sponding section of that state, will contribute much valuable as- sistance ; nor is it unimportant to the practical as well as purely scientific results, aimed at in the researches in progress in these neighbouring states, that by unity of method, harmony of views, and co-operation in the field, my brother and myself, are enabled, in various ways, to promote the accurate and expeditious prosecu- tion of our several tasks.

In concluding this brief sketch of the general features of our great coal field, a few remarks may properly be annexed in expla- nation of the modes of exploration, thus far adopted and hereafter to be still more extensively employed in carrying forward our in- vestigations in this region.

Having now acquired an accurate general acquaintance with the outline of the region, and having in some districts studied with much minuteness the most important rocky strata with their included coal seams and other deposites, it will be our object to trace the several beds composing the lower and upper series, from tract to tract, with the view of identifying particular seams, and forming correct ideas of the extent of territory over which each is of work- able dimensions, and in a position to make it accessible above the level of the streams. At the same time a careful attention will be given to the bands of iron ore, as well as the limestones accompa- nying the coal. In the execution of these tasks it is evident that in many cases accurate measurements will be demanded, requiring proper instruments to be taken into the field. Among these the boiling point thermometer, of which, as a means of measuring

heights, I have, for the last two seasons, made snooessfol use in ▼arions parts of the Bine Ridge, and the Appalachian region, and during the past sammer among the hills hordering the Kanawha, promises to afford ns great facilities, and when aided hj the com- mon instruments for levelling, will enahle ns to continue oar trac- ings with all the accuracy and expedition that could he desired.

Chapteb 2.

Of the Coal Banns ntuated between the Front Ridge of the Alle- ghany in Hampshire and Hardy Counties and the Backbone Mountain,

In the preceding general sketch, allusion has heen made to the occurrence in this portion of the state of several anticlinal axes, in the principal of which strata are met with appertaining to forma- tions geologically lower than those properly belonging to the series with wliich the coal is associated. By referring to what has already heen said in illustration of the arrangement of the rocks in the en- tire coal region, viewed as one continuous oblong trough or basin of vast extent, it must at once be evident that between any two such axes rising within the area of the coal region, the rocks including the coal must dip in opposite directions, so that as they slope down- wards along those sides of the ridges which are facing each other, they will have directions which if prolonged would cause them to meet about midway in the intervening fpace. Each stratum thus reposing on the flank of one of these ridges has its counterpart lying with an opposite inclination on the flank of the other, and thus the whole of the space between the two ridges is made up of trough shaped beds, lying one within the other, and all of them obviously superior, geologically considered, to the rocks of which the ridges themselves are composed. It is further evident that where these ridges by gradually flattening out and becoming broader as they are prolonged in either direction, are thereby caused to coalesce, the concave bend of the strata between them growing less and less, must eventually be lost, and one mountain being formed of the two, the intervening rocks must disappear, and a rounded termination be given to the trough. This change taking place at both extremities, a true bcuin woidd be formed, in which the strata containing the coal would be found enclosed in a rim of the underlying formation, not only along their length, but around the curved margins by which they were united at the ends. Such is the character of the several small basins of which 1 am about to treat, though from the length of some of them they are only in part included within the limits of Virginia.

General Limits of these Basins,

The axis known in Pennsylvania and Maryland as Will's creek mountain, and which is traversed by WilPs creek a short distance to the west of Cumberland, presents in the admirable section there dis-

dosed a broad anticlinal arch of formation IV., flanked on the KesI by the Buccessivelj higher gronps of the Appalachian series, all main- taining a northwestern dip, and presenting as we ascend from the deeply denuded valley immediately west of the monntain, the Tarions strata of YIII., IX., X., XL, and XII., forming the hills lying at the eastern base of the Dan mountain, and the eastern slope of that mountain nearly to the summit. Parallel to this margin of west- wardly dipping XII., we meet a few miles farther to the west with another rim of the same formation, inclining in the opposite direction, and forming the crest and a small part of the eastern slope of the Savage mountain. In the intervening tract occupied by a series of lofty and picturesque hills, occur the coal measures of the basin in which Frostburg, Lonaconing and Westemport are situated. In this region the Savage mountain presents only easterly dipping rocks, displaying in succession along its western slope the formations nnder- lying XII., and separated from what is called the Alleghany, lying still farther to the west, by a wide region in which these formations downwards as far as VIII., are exhibited in anticlinal orde capped on the east by the conglomerate of XII., forming the top of Savage, and on tbo west by a iimilar rock forming at many points the sum- mit uf the Alleghany.

As we trace this basin towards the south, we observe a small change occurring in the axis lying to the east, which now becomes the axis of the Knobly mountain in Virginia, the Will's creek axis proper, having died out a little to the south of Paddytown where it crosses the Potomac, and that of the Knobly, which first shews itself a few miles south of Cumberland, having now assumed great breadth and elevation. The latter axis, lying a little east of the line of pro- longation of the former, displays the same groups of strata, flanked on the western side by formations snccessively higher in the Appa- lachian series, until as we ascend the front ridge of the Alleghany, which is our Dan mountain, we pass from the upper part of XI. into the margin of the coal basin, marked by the conglomerate of XII.

The axis lying to the west of this basin, and between the Savage and Alleghany mountains in Pennsylvania, and marked on the map by a line a little west of the course of the Savage river above the mouth of Middle Fork, gradually flattens in its dips as we pursue it towards the southwest, and the country at the same time becoming topographically higher, we find the Appalachian rocks gradually dis> appearing between the Savage and the Alleghany mountains as we ascend in the direction of Crab creek in Maryland, and when we have reached the Northwestern turnpike, the two mountains have completely coalesced, forming the broad, nearly level ridge which, under name of the Backbone of the Alleghany, divides the waters of the North Branch from those of the i oughoganey. This wide table land, covered by the conglomerate of XII., extends to the head waters of the North Branch, and in the vicinity of Fairfaxes stone, sweeps around to coalesce with the same formation, which by the termination of the small basins hereafter to be described, is laid bare over the lofty wedge-formed tract comprised between the head

waters of Red oreek and Blackwater creek, tributaries of the Drj Fork o( Cheat, and the Alleghany front ridge near the western corner of Hardj ooonty.

Bat the basin thns included towards the north between the Say- age and Dan mountains, and in Maryland and Virginia between the front ridge of the Alleghany and the Backbone, begins to present marked undulations in the dip of the strata in the region lying be- tween the North Branch and Grab Tree creek, even as far north as the road leading from the month of Savage obliquely over the Back- bone. The two rolls which are here distinctly to be seen acquire greater importance as they are followed towards the southwest, pre- senting at length two well developed anticlinal axes, and thus divid- ing what farther noi*th is but a single basin into three minor basins, all of coarse lying between the front ridge and Backbone of Alle- ghany.

The eattem of thne tio axes crosses the North branch between the mouths of Abraham's oreek and Stooey river, and extending along the western side of Abrahams creek in the direction of that stream, unites with the front ridge about 3 miles south of the old Moorefield road. The apper part of the conglomerate (XII.) is exposed on the North branch a little below the mouth of Stoney river, dis- playing some undulations, but farther down presenting a uniform N W. dip, thus pointing out the western side of the axis here referred to. The conglomerate, as we follow it down the river, in virtue of the inclination just mentioned, and the passing of the river flowing nearly in an easterly course, farther into the axis, attains the summit of the ridge about 2 mUes above the mouth of Abraham's creek, and allows some of the shales of formation XI. to come into view be- tween it and the level of the stream.

This axis thus forms the broad flat ridge which throughout its course separates the waters of Stoney river from those of Abraham's oreek, and by its union with the front ridge before mentioned, ter- minates the basin to which the latter stream and its branches are oon fined. Before this union, for a distance of 5 or 6 miles, it is known by the title of tSpruce Eidge and is covered by the conglom- erate of XII. in enormous masses of a thick tabular form. The coal field thus included between the front ridge and this axis, being ob- viously continuous with that lying along the North branch between the mouth of Abraham's creek and Westemport, may be denomi- nated the Eastern or Potomac hasiriy and as will hereafter be seen, retains a larger number of coal seams, and more really valuable coal than either of the two remaining basins lying west of it and be- tween it and the Backbone.

It may be well to bear in mind that the central line of this basin passes across Abraham's creek about half a mile to the east of the junction of Johnny Cake with that stream.

The western axis is the broad flat anticlinal ridge dividing the waters of Difficult creek and Stoney river. Lying but a short dis- tance west of the axis just described, the intervening tract which may be called the Middle basin is much narrower than either the

eastern or western bflGons, and as will be inferred, presents only tboBe rocks and coal seams lying next above formation XII. This shallow concavity in the strata is prolonged in the direction of Btoney river towards the wide area of elevated land in which that stream originates, and which as already described is overspread by the strata of formation XII., and even at this remote point the synclinal or trough-like position of the rocks is not entirely obliter- ated, though here as well as in the soathem prolongation of the other basins, displaying only very gentle dips.

As will be inferred from what has been already stated, between the axis jnst described and the summit of Backbone, is sitaated the third or western of the three basins described as intervening be- tween the front ridge and Backbone of Alleghany in this portion of their coarse. This western axis is by far the widest of the three, as compared by a transverse line crossing them all within the limits of Virginia. It here includes the waters of Difficalt creek and those of the North branch from its sources to near the mouth of Abraham*s creek.

As this and the middle basin are produced by the two great wrinkles in the strata before described as commencing east of Crab Tree creek in Maryland, their width and the depth of coal rocks they contain continue to increase as we trace them south, until they attain their maximum width within or near the limits of our state — and thence continuing south are terminated by the wide area of formation XII. lying in that direction. The great width of the western basin is also in some degree due to the great flattening of the dips of the strata around its western margin, to which also, as already described, we are to attribute the union of the Savage and Alleghany mountains as they extend through Maryland, to form the Backbone of Alleghany near and within the Virginia

With the view of ascertaining whether the two axes just de- scribed, as well as the broadef and more important one of the Back- bone of Alleghany, were continued into Randolph county, a con- tinuous series of observations was made in that county along the Dry fork from the Horseshoe in a southwesterly direction to the eastern slope of the front ridge opposite Petersburg in Hardy county.

The Backbone axis, trenched deeply by the Cheat, exposes in the interval between Mill creek and Blackwater, several of the upper Appalachian formations.

The lowest of these, formation VIII., is well displayed along the central line of the axis a little south of Wolf run.

As we cross the strata towards the east, this formation dipping to the S£. disappears beneath the red slates and shales of IX., which in turn gives place to the overlying X. and this to XL, the calcare- ous or lower part of which is the highest rock met with in this part of the route.

This limestone belonging to formation XI. first shews itself about half a mile east of the mouth of Blackwater creek, dipping gently

1o the 8E. and thus indicating that it appertains to the eastern side oi' the Backbone axis.

Still continuing our southeasterly course, we see it supporting the heaving strata of red shale forming the upper portions of the formation, gradually bending in a trough-like form so as at length to present a northweBtem dip, clearly marking the continuance of the structure of the westernmost of the three basins before de- scribed among the lower rocks in their prolongation towards the southwest Gapping the bold hills through which the river here iinds its way are the massive beds of formation XIL reposing in the form of a very shallow basin on the shales and limestone just de- scribed.

Some distance higher up the stream, but west of the mouth of Bed creek, we pass through the limestone of XI. and strike upon X. — liere a coarse conglomerate, and forming an anticlinal axis, ob- viously the feeble continuation of that formerly described as inter- vening between Difficult creek and Stoney ran, and separating the middle from the western htuin.

Still further east, we have another synclinal or trough-like roll of the limestone, the eastern margin of which crosses the Flanigan settlement 2 miles west of the mouth of Red creek. Of course its dip here is to NW.

Succeeding and underlying this we have X. and IX. which arch- ing over so as to form an anticlinal axis, and being again followed by XI. lying upon the east-dipping X. of this axis, give us the repre- sentative of the ridge separating the waters of Stoney ran and Abra- ham's creek, in other words, tbat which eeparateB the eastern from the middle basin.

We now ascend the western slope of the front ridge, presenting east-dipping limestone overlaid by the red shales of XI., and reach- ing the top, we find it occupied by a shallow synclinal trough of formation XII., all that remains of the most eastern of the three hasins,

Thns are we admitted along this route to trace the undulations of the strata, which give origin further north to the several basins intervening between the front ridge and the Backbone of Allegha- ny, and to obtain confirmatory evidence, were snch required, of the existence of the structure which has already been described as seen within the area occupied by the coal rocks themselves.

Whether these axes are continued much further to the south, and there develope in the intervening troughs enough of the overlying rocks to include one or more of the lower coal seams, is a problem which can only be resolved by the exploration of this portion of Randolph county in a future season.

Eastern or Potomac Coal Basin.

It has already been remarked that as we proceed westwards from the margin of our great coal region, the axes of disturbance met with occur at mnch wider intervals, forming broader undnlations.

attended with more gentle dip?. This well marked feature, evident- ly referrihle to those mighty subterranean movements, whose influ- ences were most powerfully impressed upon the various groups of rocks occupying the Appalachian region, is beautifully illustrated in the comparatively steep inclination of the strata belonging to the most eastern of the minor basins now under consideration. Nor b it an untnteredting fact that the depth thus given to the basin, even where it is contracted to an inconsiderable width, has been instru- mental in conferring upon it the great economical advantages it pos- sesses. For it will at once appear that by this means the bottom of the trough was rendered sufliciently low to admit of the whole, or nearly the whole, of the rocks appertaining to the productive coal measures, lying upon the central or deepest parts of the trough, without towering to such an altitude as to be exposed to the de- stractive torrents which have robbed so large a portion of the area of our coal region of the coal seams and other valuable deposits once spread continuously over its surface.

Within this basin, as trenched by the North branch of the Poto- mac river, the lofty hills on the Virginia as well as the Maryland side expose to view at various points the lowest of the coal seams belonging to the true coal measures, and the principal and most val- uable seam appertaining to the upper group, so that in fact they present to our observation at once the entire lower and the most valuable part of the upper coal series as formerly distinguished.

Though striking variations are met with in the thickness and character of the beds interposed between the seams of coal at dis- tant points, and though the smaller and lower seams are seen alter- nately thinning out and re-appearing, the more important ones probably maintain sufficient uniformity of character and thickness, to be identified wherever they occur.

At least five seams extend throughout this part of the basin, the largest of which, known as the 12 foot seam, occupying the highest position, is generally found near the summits of the hills. In the vicinity of Westemport, where it is well exposed at numerous open- ing.4, some of which are on the Virginia side, its elevation above the water is between five and six hundred feet. The breast of coal which it exposes varies from 9 to 14 feet, including bands of slate and impure coal in the upper 8 or 4 feet. It is a Mmi-bituminous coal, as is the case with all the seams of this aud the other ba- sins near the eastern margin of the coal region. From its great elevation in the hills, it is not only rendered more difficult of access than the lower and thinner seams, but is of course spread over a comparatively limited area, and is moreover in some cases liable to he injured from the insufficient protection of the strata by which it b covered.

The lowest seam in this basin is found in the bed of the Potomac, a short distance below the mouth of Savage river. Above it rest heavy beds of coarse sandstones, sometimes oonglomeritio. Ascend- ing the river above this point we find the coal and sandstone grad- ually rising, until at Brantzburg the former is seen at the height of

about 20 feet above the water, haying a thioknesB of 2 feet 11 icohee of good ooal.

The second seam which at the mouth of Savage is seen near the waters edge, though not exposed immediatelj at Brantzborg, is met with in the vicinity having a width of about 20 inches.

Below the coarse sandstone, as well as immediately above and beneath the second seam are beds of olive and greenish shales and sandstones, containing above that seam a band of rich iron ore 6 inches thick. The second seam here referred to, though occurring at other points, as will hereafter appear, gradually thins out as we trace the basin towards the south, and is wanting in the basins lying west of that now under consideration.

The third team, known as the 6 foot seam, is well exposed near the mouth of Savage, in the slide, at a height, according to our measurements, of 166 feet above the river. At Brantzbnrg, the in- tervening rocks having become much thinner, its height is only about 76 feet. At this point the seam is divided into two parts by a band of slat-e 6 inches wide, leaving 8 feet 6 inches of good coid below, and 2 feet 11 inches of coal above, the upper 6 inches of which is slaty.

This seam, from the quality of the coal, its thickness, and its comparatively accessible position, as well as the wide area over which it may be wrought, is to be looked upon as one of the most valuable in the basin.

Above this there exist in the central parts of the basin from 2 to 8 other seams, known as the 6, 8 and 12 foot seams, the latter of which from its general exposure near the tops of the high hills, is the best known. Of the constancy of the occurrence of the 6 and 8 foot seams, farther observations are required before an opinion can be given. The exposures in which these seams are reputed to dis- play themselves are few in number, and have as yet been imperfect- ly connected with the upper and lower seams, but the subject is of such importance as to justify special explorations, with the view of deciding upon their position and character.

As we proceed up the North branch from Brantzburg, seam (No. 1) is seen at short intervals on both rides of the river, but affords no good opportunity of examination on the Virginia side before reach- ing the estate of Mr. Samuel Harvey, about 6 miles below the mouth of Abrahams creek. Here it displays a thickness of feet, and lies at a height above the river of 14 feet, this interval being occu- pied by 8 feet of argillaceous shales, immediately underlying the coal, and 6 feet of slabby sandstones of an olive colour extending to the margin of the river.

Higher up the hill, seam (No. 2) is exposed with a thickness of 2 feet 2 or 3 inches, and at a level 75 feet above the former. This intervening space is occupied by 80 feet of shales resting on 46 feet of sandstone, through which in some places there runs a band of slate containing good iron ore, at some points 18 inches in thickness, though very variable, and thinning out with the enclosing slate.

On the Maryland side a short distance below this, seam (No. 1)

ia shewn, eometimes separated from the OTerlying sandstones by a band of shales of very variable thickness, containing iron ore of fine

Saality, in some places as much as 8 inches in tckness. Above lis exposure, and higher up than the level at which No. 2, not seen at this point, ought to occur, a rich nodular ore occurs in consid- erable quantity interspersed in shales.

At Wilsons mill, about 2 miles below the mouth of Abrahams creek, the sandstone overlying (No. I) presents frequent undula- tions, but with a prevailing dip towards the B£., indicating a posi- tion rather west of the central line of the basin. Thonsh it does not rise high enough lust at this point to expose the ooa it brings to view the band of slate before mentioned as occurring at Harvey's lower down the river, and containing as there rich nodular iron ore, the nodules varying from one to twelve inches in diameter. The shales overlying this and separating it from seam (No. 2) are sili- ceous, coai*se, and lead coloured and abound in iron ore, rich but of a coarse texture. Seam (No. 2) is too thin to be worth working.

On the hill side near the mill, (No. 8) crops out, and the same seam has been opened on the Maryland side at an equal elevation. It is between 4 and 5 feet in thickness.

Higher up the river (No. 2) is repeatedly seen from 10 to 12 inches thick, and slaty. The shales both above and below contain the nodular ore, the nodules in the former being sometimes 18 inches in thickness.

Above Brantzburg the exposures of seam (No. 8) are rare in the hills along the river, owing doubtless to the covering of debris, but up Abraham's creek a seam is opened which is inferred to be (No. S) from its elevation and the rocks adjoining it. It is opened about 3i miles above the month of the creek, and again several miles above at Mr. Yandover's, where it is reputed to be from 4 to 6 feet thick. The same seam there is reason to think occurs on the western flank of the front ridge, a little north of the turnpike, on the estate of Mr. Johnson Co van. It is here near the eastern outcrop, and having a dip conforming with the slope of the hill, is kept too near the sms face to be well preserved, but a little further within the basin there will be depth enough of covering to afford a sound coal.

The range of hills intervening between the river and the front ridge, and known as the river hills, are generally of sufficient eleva- tion to contain the main or 12 foot seam, except where interrupted by deep transverse vallies leading to the river. This seam has been identified at numerous points both on the Maryland and Virginia side, between the opening nearly opposite Brantzburg and Elk Gar- den. The latter tract is situated in a slight depression between the river hills and the front ridge at the head of a valley which as it extends northwards becomes so deep as to separate these- hills from the ridge. It commences about 2 miles north of the lower road crossing to New creek, from which point the hills are seen to in- crease in elevation as we travel south, thus tending to counteract the rise of the coal as it approaches the southern termination of the basin. In the neighbourhood of Mr. Yanmeter's, they reach their

ffreatest altitude, and thence as thej continue towards the soath decrease in height to the valley of Abrahams creek. Here this stream, above the mouth of Johnny Cake creek, cuts through the hills, forming a little south of the turnpike a gorge, to the south of which the hills are too low to contain the main scjim, as from our near approach to the southern extremity of the basin, the lower seams, the only ones here known, are raised to a much greater ele- vation than at points further towards the northeast.

Though the Elk Garden tract overlooks the neighbouring hills both to the north and south, the gradual rise of the coal in extend- ing towards the south, brings the main seam here nearer to the summit of the hills, and thus contracts the area over which it can be worked.

From the mouth of Savage to that of Abrahams creek, all the seams of the b:isin are to be met with in the hills, excepting (No. 1), which below Brautzburg lies a few feet beneath the water, and the only diminution in the value of the tract as we approach the south- ern of these two limits, arises from the diminished area over which the main seam can be worked.

On the estate of Mr. Yanmeter, situated in the Elk Garden, where it attains its greatest height, the main seam was examined along its western line of outcrop. It consists of 12 feet of coal with a covering of slate 3 or 4 inches thick, upon which rests 8 or 10 inches more of coal. Between 6 and 7 feet below the main seam are two others, the upper 20 inches thick, the lower 12, sepa- rated by 6 or 7 inches of slate.

In the vicinity of Mr. Oovan'a, the front ridge presents a very gradual descent to a narrow glade bounded on its western side by a low hill, near the summit of which the main seam occurs.

This is a short distance to the north of the turnpike and near Abrahams creek, on the estate of Mr. Shillingberger. Lying near the top of the hill, and having little or no dip, it will be workable only over a narrow area in this neighbourhood, but will no doubt be procured in a sound condition by driving into the hiU, as there is depth of covering there sufficient for its preservation.

South of the turnpike this basin presents but two seams, viz : (No. 1) and (No. 8), the intervening thin seam having apparently nned out in extending towards the south. As we are now approach- ing the margin composed of formation XII., we are of course to look for none but the lowest seams. The upper of these (No. 8) is the one chiefly worked. On the estate of Mr. Eitztniller, situated on a branch of Abraham's creek, one mile east of the mouth of Johnny Cake, it includes 3 feet of good coal, overlaid by 18 inches of slaty coal, and covered by soft argillaceous shales.

The same seam has been opened on the estate of Mr. Yandiver, just above the mouth of Johnny Oake, where it is 8 feet thick, but impure throughout, and having near the bottom the appearance of being partially coked. About 3 feet above the seam is a band of slaty coid resembling lignite. This is a very 'usual accompaniment of (No. 8.)

This seam has also been opened on Abraharas creek, 6 miles above the month of Johnny Cake, on the estate of Mr. Hide. It is now concealed, but said to yield between 2 and 8 feet of good coal, having a doll surface and looking like cannel coaL Thronghont this part of the basin, as might be expected, the dip is towards the NW., for we are here east of the central line. A seam agreeing with this in character and association, and no doabt the same, is exposed a short distance south of the Moorefield road, both on the east and west forks of Abraham's creek.

A lower seam (No. 1) is also met with towards the sonthem termination of the basin, but has not been explored. At Mr. Van- diverts it has been found to be good coal, and is situated at some distance below the other seam, (No. 8,) before mentioned as occur- ring on his estate.

As already intimated, additional explorations are yet to be made in some parts of this basin, having a special view to the seam or seams next beneath the 12 foot seam, the obscurity of the exposures thus far met with having precluded any decided inferences as to their position, continuity or thickness.

Middle Basin.

In this as in the corren)onding part of the last basin, there are but two seams of coal. These by the associated rocks, as well as the character of the coal, shew themselves to be the same with the two found in the southern portion of that basin. The upper, which is every where the thicker seam, has been opened on tne estate of Mr. Nevil, on Stoney river, about 2 miles below where the turnpike crosses that stream. It here yields about 8 feet of good coal, over which lies a thin seam of slate, and then about one foot of impure coal. Above the seam is a very thick bed of sandstone exposed to the height of 20 or more feet, a seam of very fine grained slate sometimes coming in between the sandstone and subjacent bed, but not uniformly present. As a general feature, the rocks of this basiu are remarkable for their variability in thickness and composi- tion. As one instance of this, I would cite the fact that only one mile further up the river the seam of coal just mentioned is overlaid by slates and shales. At this locality it yields about 2 feet of good coal, over which is about 18 inches of impure slaty coal. At a still higher level occurs a vein of impure iron ore, which for more than a hundred yards presents a uniform thickness of 2 feet. It is how- ever a rather poor one, though not poorer than is of fen worked. Upon this ore rests a seam (about 2 feet) of very fine grained ho- mogeneous slate, having a smooth and regular cleavage adapting it either for roo6ng or writing slates. Eight miles above this, at the falls of the river, this seam, or rather its representative, is exposed, sometimes consisriug of 2 bands, each about a foot in thickness, sometimes divided into 8 or 4 thin seams. Frequent alternations of character are thus presented in the coal seams as traced from point to point, a band of slate usurping the place of coal, and being again

replaced hj that material. This seam has not been found on the river between the two last mentioned localities, but it mast occar a short distance inland, as the calcareous rock underlying it is met with at several points on the river intervening between these lo- calities, clearly indicating the existence of the coal in the hills a little removed from the river, though along its margin no exposures are to be seen.

The lateer seam was opened several years ago on the estate of Mr. Cunningham, a short distance north of the turnpike, but the caving in of the superincumbent shales prevented any examinations at this point. The seam is said to yield from two to three feet of coal of good quality.

Eight or ten feet beneath the coal is a band of impure limeBtone two or three feet thick, included in calcareous, argillaceous slates, and occasionally containing nodules of iron ore. This rock has been used for lime.

About three miles below the turnpike on Stoney river the sand- stones and elates, identified as those overlying the lower seam, are exposed for a short distance, at first horizontally, and afterwards assuming a SE. dip. These slates are beautifiilly fossiliferons, abounding in ferns and other vegetable impressions, and moreover contain two bands of very rich inm ore the upper varying from one to six inches, the lower from two to three.

Higher up the hill the peculiar calcareous rocks, elsewhere seen to separate the upper or second seam from the lower, are slightly exposed, consisting in part of a quite pure limestone. The upper seam may therefore be expected at a greater altitude in the hill not far above the limestone.

Four miles above the turnpike the lower uam is again exposed, sometimes divided into two, each about a foot in thickness, the separ rating material being a thin seam of slate. In other places the in- tervening slate expands to a thickness of two or three feet, and thin bands of the same material appear in the upper and lower portions of the seam dividing them into five or rix thin layers.

The limestone underlying the coal occurs just at the rivers edge, exposed to the depth of three or four feet, which is probably its foil thickness. It is of a dark blue colour and fine grain, more ar- gillaceous above than below, and containing nodules of pure iron ore near the bottom.

This seam also shews itself at the falls of the river 7 miles above the turnpike, consisting here of several thin bands, only the upper one of which crops out from beneath the bed of the river. It is about one foot in thickness, of good quality, but disposed to crum- ble. Of course the underlying limestone is not exposed, the coal being the lowest stratum in view, but it must occur not far inland, as the dip of the rocks would there cause it to crop out. Above the coal, ana separating it from the calcareous rock hereafter to be mentioned, are shales and shaly sandstones, in the lower part of which, and immediately over the coal, is a rich band of inm ere four inches thick.

Limestone hetween the Firet and Second Seame,

Wherever in this basin a sufficient depth of exposure was met with, a calcareous band of rocks was found to intervene between the upper and lower roal. All the inerabers of this band are of a light lead colour, and are usually calcareous, though assninin the characters of shales and sandstones, and occasionally of quite pure limeetones and generally including one or more seams of iron ore. This band seen imperfectly exposed on Stoney river about three miles below the turnpike, but the presence of iron ore in it could not be satisfactorily ascertained, from the obscured condition of the strata. Four miles above the turnpike it is again exposed on the river, overlying the lower coal, and separated from it by 15 or 20 feet of shales and sandstones. It here abounds in a rich iron ore, occurring in nodnles sometimes eight and ten inches in diameter, fine grained, homogeneous, and of a delicate lead colour. Besides this variety, it also contains another and coarser kind, quite siliceous, and having the aspect of a poor ore when freshly fractured, but upon exposure assuming a deep ferruginous hue. This is irregularly distributed in the shales.

At the falls of Stoney river the same band is again exposed, with a thickness of from 15 to 20 feet, in the upper part siliceous, in the lower shaly. Here the coarser variety of ore predominates, and is found in great abundance. At the preceding localities the rocks in question shew themselves 30 or 40 feet above the waters edge, but five miles above the turnpike, owing to the rapid rise of the bed of the stream, they are exposed immediately above it, but too imper- fectly to ascertain the extent of iron ore included in them.

At the falls of the river the calcareous band rests immediately upon the lower coal, whereas at other localities they are separated by more than 20 feet of other strata, so that it is impossible to give any rule of general application as regards its distance from the lower or the upper seam.

The importance of this band, due to the valuable layers of lime- stone and iron ore it contains, cannot fail to suggest to those inter- ested in this region, the advantages that may be derived from an examination of its contents wherever it may be exposed. Nor should it be forgotten that the limestones of this band, as well as the similar rock occurring beneath the lower seam, are of sufficient purity to be made subservient to the agricultural improvement of the neighbouring country.

It may be added, that at some points the micaceous slabby snnd- stones have a cleavage that admirably adapts them for flagging and similar purposes.

JFestem Basin.

The coal measures of this basin extend high up on the western flank of the ridge, separating Stoney river and Difficult creek, and there expose a coal seam, which, by comparing the associated rocks, has been identified with the vpper of the two seams described aa oc-

oarrlnfc in the last benn. "So opening however, have been made oa the Virginia side of the baaio. Judging from the oaterop of this ae&m it inolndes about two feet of good and one of impare coal. Aa might be inferred ftom its lying Dear the eastern margin of the basio, ita dip and that of tbe encloaing nicks is to NW. Biill lower down the hill, and geologicslly oDdemeBth the upper seam, the calcarcons band is exposed. aas<'ciatcd with iron ore. which appears by inSltra- tion to have been converted into peroxide.

TTit lower uam shews itself in the bed of Diflicalt creeic, a short diatsDce above the tnmpike, presenting a tbictcnesa of abont one foot. On the eastern side of a bold hill, interposed between Diffi- cnlt oreek and the TS. branch, we meet with the calcareous band, and at a higher level the overlying coal seam. Above the coal, and forming the npper part of the bill, is a considerable thickneM of olive drab ahales, which are well exposed on the turnpike, but give no indicatioos of either iron or coal. Jnat to the east of the North branch these shales are seen to change their dip from NW. to SE., indicating the pogitlon of the centre of the basin. It is extremely improbable that any other thnn the two seams already mentioned, have been retained in this portinn of the basin on tbe Virginia ude, hnt in Maryland, ascending the bold flank of the Back- bone from the North branch, one, and probably two, higher aenms oconr. Not having been opened their thickness is unknown, but should future explorations prove them valuable, it wonld be advis- able to search for them further aoath on tlje Virginia side, wliere, Caibly. through the leu denuded state of the aurfaoe, they might found high up In the hiUe.

Crapteb S.

Batiiu qf Freiton and Motxtnaalia Covntiet — Mount Carmel Ba*in and Briery AxU.

The Backbone of Alleghany, west of the last of the three minor bnsins above described, is a broad anticlinal axis, flanked and for the most part capped by formation XIT. Of course, therefore, while tbe conglomerate of its enatern slope is seen dipping gently tiwards the 8E. BO as to underlie the coal measures of the basins imroediutely east of it, tbat of its western side presents the contrary inclination. But owing to the abort interval between these gentle western dips, and the recurrence still farther to the west of eastern onea, the beds of formation XII. forming the shallow troagh across wLlth [his Northwestern turnpike passes, are either at or very near tht sur- face, and (bus in this region no coal rocks are seen in the intirr.il between the backbone axis and that lying next west of it.

This shallow basin, however, expands and deepens as it etftriOs in a northwesterly direction through the adjoining parts of Mury- land, and when traced into Pennsylvania is found to be idcniii/nl with that described by my brother, prof. H. D. Rogers, as includi-d between the azea of the Allegbony and Negro monntaina.

The wide region of broken and loftj hills, very erroneously traced on the map under the name of Briery moantain, where traversed by the Oheat river, displays the underlying Appalachian rocks forming a broad anticlinal axis, comprising the formations from IX. to XL in- clusive, the eastern slope of which forms the western side of the basin here referred to, while the western slope extending nearly to the Cheat river, directly east of Kingwood, becomes the eastern mar- gin of another basin, in the midst of which that town is situated.

Of the eastern and western limits of this broad tract, occupied by the lower formations, and in which, therefore, the coal measures are no where to be found, the several subjoined details will enable the reader to form a correct opinion.

At Mount Carmel and along the valley of Bhine creek formation XII. has been swept away, leaving the underlying rocks of XI. ex- posed. At Mr. Schaefier's in this valley, about one mile, to the south of German Settlement, the limestone (XI.) of the eastern side of this basin is displayed to the depth of from 20 to 80 feet. The rock is of a dark greenish grey colour and quite foetid, yielding an impure though workable lime. No traces of it are to be met with on the turnpike.

The centre of this basin passes through Mount Carmel, where the limestone is exposed. The upper beds of the same rock are also seen a short distance to the SW. of the village on the cross road leading to the Kingwood road. It is here underlaid by a sandy limestone, adjoining which the upper bed is impure, though still higher it is of great pifrity. Near this the upper part of the loutr limestone is seen, consisting of rock of very good quality. Que mile to the 8W. of Mount Carmel the lotcer part of the lotoer limeitons displays itself of a delicate greenish drab colour, and one fourth of a mile still more towards the west, as we approach the mouth of Salt Lick, we pass out of the limestone and enter the next forma- tion (X.), west of which we come upon IX. which continues to the mouth of Salt Lick.

In the vicinity of German Settlement, on the summit of a high hill on the northern side of Rhine, is the outcrop of a body of iron ore of superior quality. It occurs on the surface over a wide area in large fragments, and is also found a short distance beneath. These fragments are evidently in place, and are portions of a bed which occurs near the surface, in the upper part of formation XL

The conglomerate of the western side of the basin is seen i mile to the east of where the road crosses Snowy creek. It is here very irregular in its line of outcrop, owing to great inequality of denuda- tion, and forms a low hill which both to the north and south of the road rises to a much greater elevation. This high ground termi- nates to the north of the valley of Rhine creek, where the under- lying rocks are exposed.

The lowest formation seen in the Briery axis, south of the IMney swamp country, is IX. On the Uniontown road leading through Mount Vernon, the conglomerate of the eastern side of this axis appears not far to the west of Herndon creek, and its line of out-

cfop which is here quite irregular, is for 8 or 4 miles nearly coin- cideut with the state line, encroaching a little on the Virginia side.

This axis is denuded into irregular lines of hills, all of which attain a nearly equal height, viz : about 1600 feet above the level of the Cheat river opposite King wood.

The Umutone of XI. of the v>etem side of this axis is exposed half a mile west of the Uniontown road, on the estate of Mr. Ohris- tian Smith, in the yalley of Roaring creek. At this place only about 8 or 10 feet of it are seen, consisting of fine grained dark and light grey limestones of excellent quality.

Where the axis is crossed by the Uniontown road, formation X. is not met with in mass, but fragments of its olive coloured con- glomerate bestrew the surface. On the Kingwood road, however, formation X. of the eastern side of the axis comes in view a short distance west of Snowy creek, presenting of course a southeastern dip. On the creek, and therefore east of X., the limestone of XI. makes its appearance.

On the western side of the axis the limestone is exposed at many places south of the Kingwood road, and both its upper and lower divisions are seen about 4 miles from the road in the same direction. The former consists near the top of a fine grained dark bluish grey limestone, in the middle of a similar rock having a light grey colour, and at bottom of a dull bluish rock less pure than either of the pre- ceding. The latter is of a light grey colour and very pure, and judging by the fragments seen around, is underlaid by the usual bed of sandy limestone. Both the upper and lower limestones are fre- quently exposed between this and where the Oheat passes through the axis, and along this deep trench in the mountain it displays itself in a bold escarpment.

At £verlie*s mill on Muddy creek, the limestone of the western side of the axis is met with of a deep blue above and a light grey below, and throughout homogeneous and rich. It here rests upon a red sandy limestone or calcareous sandstone. The Pine swamp region is made up of the rocks of formation XL, the limestone gen- erally at the sur&ce. The most eastern exposure of the limestone of the western side of the axis is on or very near the state line. About half a mile east of this line formation X. comes in view.

The limestone of the eastern side of the axis is extensively ex- posed on the Youghioganey at the mouth of Hoys run in Mary- land. It is of a deep blue colour, impure and slaty, and highly fos- sil iferous.

Opposite Kingwood the western boundary of the conglomerate is 2 miles east of Cheat river. Further north the eastern boundary of the conglomerate is miles east of where the road crosses Roar- ing creek.

This axis is cut through by the Youghoganey, which leaves it not far above the mouth of Bear creek. To the north of this, the main central ridge of the axis is known as Negro mountain, and the western ridge, which is the continuation of the Briery mountain of Virginia, is called Winding ridge. This ridge is capped by the con*

glomerate of XII., the western boundary of which is miles to the east of Petersbarg.

To the iouth of where Cheat river leaves this axis, it is divided into two bold ridges ; the eastern one, that which you descend in going from Mount Garmel to the river, is known as Cheat moun- tain. No. X. is exposed near its summit, 8 miles southwest of Mount Garmel.

It is impossible to define the western boundary of the conglom- erate on the summit of this mountain, as there is a wide area to the west of Mount Garmel, without exposure, being a flat country, the soil of which is rich in the pebbles of the conglomerate of XI L, leaving no doubt of that formation being almost immediately be- neath the surface and in a horizontal position. In the centre of the axis, which is at Hooton's, the rocks of IX. are thin and large, and interstratitied with olive shales like those of No. V III.

The ridge made up of the western side of the axis is known as Laurel mountain. The eastern boundary of the conglomerate dip- ping W., flanking and capping it, is 2i miles W. of the mouth of Big Bufialoe.

The limestone of XI. is slightly exposed on the eastern flank of this mountain, 2 miles W. of the mouth of Big Buffaloe. It is argillaceous, and of a dingy grey colour, but burns into a workable lime.

Chapter 4.

Kingwood Basin and Kingwood Axis the same as the Laurel Hill

Axis of Pennsylvania,

West of the Briery axis, just described, there occurs a narrow though important basin, including coal seams and other valuable deposits, whose boundary on the west is formed by a low and gentle axis, the continuation of that described by professor H. D. Rogers as the Laurel Ilill. On looking at the map, it will be perceived that after crossing the Cheat river, the Briery mountain is represented as pursuing a N£. course for about 10 miles, and then taking a direc- tion due north to the head of Little Sandy creek in Preston county, after which it again assumes its northeastern bearing, passing into Pennsylvania, where, some distance north of Smithfield, it is known as Laurel Hill. By the delineation thus presented, the false impres- sion is likely to be made that the whole of this winkling tract of highlflUfis constitutes in reality one range or axis, while in fact it comprises two. The eastern or Briery axis has already been de- scribed as following the direction indicated on the map, from the Cheat river to Pine swamp, passing through and a little west of the latter tract in the prolongation of the same northeastern line, and following the direction of the Youghoganey towards Selby's Port, so as to pass a little east of Smithfield on the National road in Pennsylvania, a few miles north of the state line. Throughout much of this tract, the denuding agencies have cut down this elevated region into a series of hills or knobs, so as to present but little indi-

cations in the topography of the regalar coarse of the axis here referred to.

The western axis, of which on the map a small portion is deline- ated near the N£. comer of Preston county, is in reality condnned in a southwesterly direction a little west of Kingwood, and forms, as already stated, the western boundary of the basin of which I am about to treat. The ridge delineated as connecting the two axes, in a north and sonth direction, a littie west of the Preston line, is in fact a part of this bann occupied hy comparatively high ground, and comprising the coal measures intervening between the two axes just described. I have been thus particular in correcting the erro- neous impressions likely to be produced by an inspection of the map, from a wish to convey to the reader a clear conception of the region in the present instance so falsely indicated by the topography laid down on our map, and from a conviction that accurate knowl- edge of this description furnishes the only guide to sure and suc- cessful research.

The following data will serve to indicate the course and bounda- ries of this basin, as well as to illustrate the nature and extent of the valuable materials which it includes :

North of Kingwood, the conglomerate of XII. is but slightly exposed on the summit of this western ridge, (Kingwood axis J and is rarely seen in place over an extensive area. On the Brandonville and Selby's Port road, 6 miles from the latter and 2 miles east of the junction of this and the Crab Orchard road, {vide map,) it is seen in tabular masses, but does not here form a distinct ridge, the coal rocks rising to an equal elevation. It may thence be traced through a point miles west of Muddy creek on the Bracdonville road, and across the Cheat a short distance above the mouth of Laurel run.

The limestone of formation XI., nnderlying the conglomerate of the eastern side of this axis, rises above the water's edge on the Cheat, about i mile below the mouth of Laurel run, and continues in view for about half a mile. Including the intcrstratified argilla- ceous shales, it is here about 80 feet thick, the upper 50 or 60 of which consists of a deep blue and bluish grey rock, highly bitumi- nous and fossil if erous, and largely intcrstratified with soft argilla- ceous shales, and sometimes, though rarely, with pinkish calcareous bands. The lower 15 or 20 feet include light grey and bluish fine grained limestones, very rich in lime, frequently displaying the oolitic structure. Associated with these lower bands, we find layers of a dark lead colour, presenting a strong ferruginous stain where weathered. This variety, as will hereafter be seen, yields a good hydraulic lime.

About of a mile below the mouth of Laurel run, the limestone ceases to be exposed, and we meet with fragments of coarse sand- stone strewed profusely over the surface, belonging to forma- tion X.

The limestone of the western side of this axis is exposed on Cheat river, ( of a mile above the month of upper Bee run, and

36:1

though badly displajed, evidently exists in a large body. Mach of it is of excellent quality, and yields a superior lime. Overlying the limestone is a massive sandstone, slightly calcareous, and varying in colour from a dingy white to grey, fine grained and homogeneous, 15 or 20 feet thick. The red slates and sandstones of the upper part of XI. are also here slightly exposed, and contain iron ore of supe- rior richness, though apparently in thin seams.

Two miles west of King wood, the conglomerate shews itself over a width of about of a mile, though even within that area its depressions are occasionally filled with tbe shales of the coal meas- ures. It does not occur on the summit of the ridge, but rather to- wards its eastern side.

As it extends in a southwesterly direction, this axis opens out and at some undetermined point between this and the NW. turn- pike, brings formation XI. into view. Where intersected by the turnpike, it forms the two ridges crossed in going from Evans- ville to the Tygarts Valley river. The most eastern of these ridges, known as the Three Fork Hill, presents the conglomerate on its eastern side, passing out of view with a gentle southeast dip. This occurs i mile west of where the turnpike crosses the Three Fork creek. The western of the two ridges, called Fort hill, is flanked towards its western base by the same rock, here of course inclining to NW. This is seen 2 miles west of Tygart's Valley river.

The valley between these ridges is made up of the upper rocks of formation XL, but they are not sufficiently developed to expose the limestone.

At Eingwood the basin is 6 miles in width, but in the neighbour- hood of Evansville it is much wider. At the same time, however, its depth does not appear to be increased, and hence unless some important change in this particular shonld occur as it extends still further south, there is no reason to anticipate the existence of any higher seams of coal in that direction, than in the part of the basin lying between Kingwood and the turnpike.

As far as this basin has yet been examined, it contains but three Beams ofeoal the two upper ones alone being worked. Of the hvo- est seam but little is known. It is said to be in view in the bed of Cheat river at very low water, half a mile below the Eingwood ferry, and was slightly exposed a few years ago by a slip at Snyder*s mill, on this river, resting as is affirmed upon a limestone. It has been worked only at one locality, bnt the opening is now concealed. This seam, on account of its low position, will only be accessible where the Cheat river cuts through the centre of the basin. Where formerly opened, at the point alluded to above, one mile below the Eingwood fefry, the shales which overlie it contain 00 hands of rich iron ore within the space of four or five feet, the lowest band occa- sionally fonr or five inches thick, the upper ones generally about two inches.

The middle seam generally yields from two to three feet of coal which is valued for fuel, but rather too sulphureous for the forge. Being more conveniently placed than the upper seam, and being ex-

posed on both the eastern and western sides of the basin, it is very generally mined.

The upper seam wherever met with, is found low down on the flanks of the hills. Besides a general examination of this seam in different parts of the basin, particular attention was given to its ex- ploration, and that of its associated strata, as displayed on the flanks of the hills bounding the Cheat, where peculiar facilities existed in aid of our investigations. Where this seam has been explored by colonel Faii*fax at several localities, south of the Kingwood ferry, it varies from two and a half to three feet in thickness, and is overlaid by about a foot of slaty coal. Beneath it is a calcareous rock, the upper two feet of which is shaly, but the lower four or flve, com- pact and tolerably pure linietone. The shales overlying the coal abound in nodules of a very rUh iron ore of a delicate grey colour.

The same seam has been opened at various places near the river, but owing to the circumstance that the mining is performed in the winter only, the workings, when visited, were not in a state admit- ting of satisfactory examination. Where worked on the west side of the river, a quarter of a mile south of Kingwood by Mr. Price, the seam is two feet six inches thick, not as usual covered by a layer of slaty coal. It is quite sulphureous, of a compact texture below, but inclined to crumble towards the top. The iron ore found in the overlying shales on the opposite side of the river is here replaced by nodules of impure limestone.

The limestone situated beneath this seam is not here in view, but presents itself a quarter of a mile further south, not in a solid stra- tum, but in nodules three or four feet in diameter. It is however rich in lime.

About a quarter of a mile west of the ferry, this seam is worked by Mr. Kelso, and is here covered by shales containing rich nodules of iron ore, and rests upon the usual bed of limestone. It is seen near Snyder's mill with the limestone beneath, the latter said to be four or five feet thick, and of a character to furnish good lime. On the estate of Mr. Crane, on Sypole run and on Muddy creek, the seam is divided into two portions by a band of slate Ave or six inches thick, the upper portion about two feet wide, the lower unknown. It was also identified at several other localities in the northern por- tion of the basin, but the exposures were too partial to give correct information either as to the thickness of the coal or its character.

On the western side of the basin the snme seam is worked on the estate of Mr. Higgins, half a mile west of Kingwood, and here it is but 18 or 20 inches thick, though further south in the same meridian it expands to four feet.

The upper eeam is generally mined on both sides of the basin, on the summit and high up on the fianks of the ridges, but towards the middle of the basin the hills are rarely of suflicient altitude to allow of its being present. Though apparently wanting or partially re- placed by other rocks in that part of the basin lying to the west of Kingwood, it is of general occurrence and quite accessible in posi- tion throughout the remainder of the basin. (See Appendir.)

The cod of this seam is generally of a better quality than that of either of the lower ones, but as will be seen by the following de- scriptions, is very variable in thickness. At Mr. Beatty's, 8 miles south of the mouth of Bufifalo creek, it measures about 4 feet, in- cluding 8 or 10 inches of impure slaty coaL It is very compact, ot a dull lustre, and striated structure, with its fracture perpendicular to tlie StrisD, and breaks with difficulty. It is much approved by the blacksmiths. One fourth of a mile south of this, where opened on the estate of Mr. Wolf, its quality is the same, but its thickness is reduced to about 8 feet.

Two miles SSW. of the mouth of Buffalo creek, on the estate of colonel Fairfax, the seam is divided by a band of slate 6 or 8 inches in thickness, inclusive of which it has a total width of 6 feet. At Mr. MurrelPs, on the head of Deep Hollow run, it has dwindled to a width of 16 or 20 inches, and near Snyders mill it measures about the same. At the former locality the overlying shalea are very rich in fossils in a fine state of preservation.

On the western side of the basin opposite Eingwood this seam is much thicker. On the estate of Mr. Higgins it measures 7 or 8 feet, including the interpolated shales, and yields about 5 feet of coal, 8 of which is in one uninterrupted stratum. Corresponding to this increase of thickness, there is an improvement in the character of the coal. But the expansion here described is quite local.

Limestone of the Kingwood Basin,

The coal measures of this basin contain 8 bands of limestone. The lower bandy underlying the lowest coal seam, is exposed hut onee in the bottom of the river near Snyders mill. Its character and thickness are as yet, therefore, matters of conjecture.

The middle hand underlies the middle cod seam, and has been already alluded to in the description of that seam. It often attains a thickness of 4 or 6 feet, and from its purity and frequent exposure, is to be esteemed a valuable resource m connection with the agri- cultural improvement of this region, as well as for other uses to which it may be applied. Should its powers as a hydraulic cement correspond with external indications, and the results of the trials I am now making, it will acquire a new claim to the attention of those interested in its development. The average thickness of the bed, as examined at a great many places, is about 4 feet It is usually of a light grey or delicate lead colour, fine grain, homogeneous, and pos- sessing a very smooth fracture. Though often largely impregnated with iron, it is probably never so much so as to be unfit for mason- ry, to which it has been frequently applied with satisfactory re- sults.

The upper hand of limestone is found between the middle and upper coal seams at variable intervals from each. It is associated with a white argillaceous clay and shales of a very peculiar charac- ter, andogous to those met with in a similar position in the Hardy basins, and which there contdns iron ore. Here, however, the ore

is replaced by nodales of limestoDe, which are sometimes quite f er- roginoas, thongh always containing a preponderating amount of limestone. In many portions of the basin these nodules are replaced by a stratum of limestone, frequently four or five feet in thickness, which is generally exposed on the hills flanking the Cheat, in con- nection with the peculiar clay and shales before mentioned. On the western side of the basin the clay and shales are wanting. As stated above, this band varies in its position between the two coal seams, being at some localities 50 or 60 feet above the lower seam, while at r. Uagans the two are only separated by four or five feet, and on Sypole run by eight or ten feet. This and the middle limestone are so much alike, that it would be difficult, by aspect or composi- tion, to distinguish the one from the other. When largely impreg- nated, as it sometimes is with iron, it bums with difficulty, and slakes slowly, but nevertheless makes a valuable lime. From the trials now in progress, of which a partial report will be given in the sequel, it will be seen that portions of this rock form an admirable water cement.

Iron Orbs. — The occurrence of iron ore has been alluded to, in- cidentally, in describing the coal and limestone. Besides the local- ities thus referred to, several others will now he noticed. One of a very superior quality occurs on Deep Hollow run, a tributary of Muddy creek, near its junction with that stream, which is two and a quarter miles above its mouth. The band varies in thickness from three to twelve inches, and apparently over a wide area. Beneath it, a distance of three or four feet, is a calcareous shale containing nodules of impure iron ore, eight or ten inches in diameter. It may be added, as imparting high value to this ore, should it be found to continue of the requisite thickness, that Muddy creek affords a suffi- cient fall of water, and is proverbial for maintaining its stream un- diminished throughout the summer.

A very rich ore occurs on the surface, on the estate of Michael Hartman in the Crab Orchard : the fragments are strewed on the surface over a wide area, and indicate a continuous vein. It is fos- siliferous, of a dark red colour and very pure. Its place is probably either a few feet above or below the second coal seam.

The shales of the coal measures very generally contain iron ore in small nodules, but the indications do not favour the opinion that a large amount of ore is to be met with in this basin. As near Mor- gantown, and in other parts of the great coal region, the shales im- mediately succeeding to formation XII., were found very rich in ore ; examinations were made in the corresponding strata of this basin, without discovering any decidedly abundant seam, though small bands were continudly met with. It may be well to add, that the Bear creek furnace, near Selby's Port, was formerly supplied with ore from these shales, which, on the National road, east of Petersburg, appear to contain a band of valuable thickness. It is, therefore, by no means improbable that further investigation may disclose this material in the same geological connection ftirther soutb in sufficient amount to be economically valuable.

Ohaptsb 6. Preston BasiM, tceit of the Kingwood Baein, and Preston Axis,

In PennsylvADia, and on the VirgiDia side near the state line, the axis last described as bounding the Kingwood basin on the west, constitutes the eastern boundary of a coal basin, which is bounded on its western side by the Chesnut ridge of Pennsylvania or the Laurel hill of Virginia. But as thb basin extends south, it is divided into two by the development of an anticlinal axis, which, for the sake of distinction, I will designate as the Preston axis, 'this axis was not recognized farther north than the Morgantown and Crab Orchard road, which crosses it one and a half or two miles east of Big Sandy. The conglomerate of XII. is there slightly ex- posed on the summit of the ridge, and also at its foot on Sandy, though the flank of the ridge is covered by the coal measures, which at this place are locally removed. Between the months of Gum Camp run and Big Sandy, the rocks of X. of this axis are exposed on the Cheat, consisting generally of a reddi grey sandstone. Overlying these we have the usual reddish grey, fine grained sand- stones, very obliquely stratified, internally of a light grey colour, slightly calcareous, 20 or 80 feet thick. Overlying these a fine grained limestone is slightly exposed. These rocks have a very slight inclination to the NW.

This axis is exposed on the Morgantown and Kingwood road five and three quarter miles from the latter, which makes the eastern basin about three and three quarter miles in width; the original basin is therefore about equally divided by this axis, the general width of each being about four miles.

The most southern exposure of this axis is on the road from Kingwood to Smithfield in Monongalia county, miles from the former place, where it developes quite a prominent ridge. On this high ground, the coal rocks are very irregularly denuded, and in some places occur on the summit of the ridge, though the conglom- erate is there generally exposed. At this point, the eastern of these two coal basins is not more than 2 miles in width.

But little is known of the coal seams south of tiie commencement of this axis, as our examinations have as yet been confined to the neighbourhood of Brandon ville. At this place there occur three seams of coal, which we succeeded in identifying with those of the Kingwood basin. The lowest of these, as in the Kingwood basin, is too low to be generally accessible. It was exposed in the bed of Sandy in making the examinations necessary for sinking the sills of the bridge, but nothing could be learned respecting its thickness.

The middle secnn is most generally worked, though usually thinner than the one above. Where opened near the bridge over Big Sandy it is said to be 4 feet thick. The coal is quite sulphure- ous and overlaid by a highly carbonaceous slate. It is also quite variable in thicknes, as will appear from the fact, that on the estate of Mr. Rhodoheavor, one mile east of Brandonville, it measures only

2 feet 9 inches. Though worked in nnraeroos places in the neigh- bourhood of Brandonville, the condition of the openings which are in nse only in the winter, made it impossible to examine the seam, excepting at a few points.

The upper team worked at a higher level on the hills, is supe- rior to that of the middle seam, bat its thickness and local charac- ters remain for future investigation.

Ijmestoke. — Between the middle and upper coal seams is a band of limestone about 4 feet thick. It is of a dark bluish grey colour, fine grain, smooth fracture, and like most of the limestones of the coal measures, slightly ferruginous. This band has been quarried near the Sandy bridge, and is seen on the estate of Mr. fihodo- heaver, one mile east of Brandonville.

One and a half miles above the bridge on Big Sandy is a bed of coarse iron ore which appeared to be upwards of a foot in thickness, and a similar ore is associated with the limestone.

Whether these three coal seam* are contained in the basin after the development of the axis, is yet to be determined. That portion of the basin lying north of Cheat river was examined as minutely as the scarcity of openings would permit. From the impeiiect data yet collected, it would appear probable that the upper of the three seams is met with in this portion of the basin. As occurring on Mr. Seaport's land, it measures 4 feet, and presents at some depth be- neath, a fine grained, homogeneous, argillaceous and siliceous slate, much approved of as an oil stone.

A limestone of good quality occurs in this basin, but its position in relation to the coal seams has not yet been determined. On the estate of Mr. Walls this band is about 4 feet thick, it is also slightly exposed on the estate of Mr. Gribblo. In the Monongalia Glades, if report be true, the coal seams above noticed must be developed in much greater thickness than usual but on this subject future observations can alone enable me to decide.

Chajteb 6.

Laurel Hill Axis — Its Limestone a/nd Iron Ores,

The broad elevated tract extending from Pennsylvania into Pres- ton and Monongalia counties, in a direction nearly coinciding with their common boundary, and which is described on our map under the name of Laurel Hill, contains another and the last important axis met with in tibis part of Virginia. As followed in a south- westerly direction, the dips of the rocks on both sides of the ridge are seen rapidly becoming less, and the axis thus flattening out soon buries from our view the Appalachian strata previously exposed, while the ridge itself subsiding to a less and less elevation, is at length entirely lost in the general level of the country. Beyond this point, which is near the head of Field's creek, a tributary of Three Fork, there is in reality no mountain such as delineated on our map, but an undulating region scarcely to be distinguished from

the acyoining tracts on either side, and all that remains of the orig- inally conspicaouB axis is merely a gentle roll or broad wrinkle in the coal measures, of too little force even to bring the conglomerate of formation XII. into view. Hence more correct conceptions of the topographical as well as geological featores of this tract would be imparted were all that portion of the Laurel Hill laid down as extending south of the head waters of Field's creek obliterated from the map.

The few details annexed will serve to shew the position of the eastern margin of the great coal region extending from the western flank of this mountain across the valley of the Monongahela, but much farther exploration must yet be devoted to this region, before I shall feel prepared to enter into a minute description of its struct- ure and contents. The value of the ores and limestones associated with formation XI. and with the lower coal rocks of the Laurel Hill axis, will be illustrated sufficiently for the present, by the accom- panying descriptions of them, as seen at several important localities, as well as by the details of their composition comprised in the chem- ical division of the report.

The upper limestone of XI. forming the eastern side of this axis, first rises above the surface near the junction of Lower Bee run with the Cheat where it is boldly exposed. So much of this lime- stone as is here in view, amounting to about 20 feet, is seen to con- sist of rocks generally of a fine grain, smooth fracture, and dark grey colour, though sometimes bluish black.

Between the upper and lower limestone are about 30 feet of sandstone of a light grey colour, less calcareous than that which usually underlies the limestone, and wanting its diagonal markings. Beneath this sandstone is about 4 feet of limestone of a light grey colour, having much the same aspect as the overlying sandstone. Beneath this is about 4 feet of a less calcareous rock, of a light grey colour, largely impregnated with iron. "Beneath this we en- counter the gritty or sandy limestone with the characteristic mark- ings running obliquely between the surfaces of stratification.

The limestone of Uie eastern side of this axis is again slightly ex- posed at the quarry of the Greenville furnace, in a gorge of the mountain near the state line. These are the only exposures of this rock as appertaining to the eastern side of the axis, north of the Cheat river.

The conglomerate (formation XII.) of the eastern side of this axis shews itself about of a mile to the west of the county line, where it is crossed by Laurel run. It is well exposed in the lateral gorges of the mountain, where it is seen stretching at a gentle angle from the base to the summit. It generally covers an area from ( to 1 mile in width.

On the summit of the mountain is a narrow denuded valley, com- posed of the upper part of XL The denudation is not here deep enough to expose the red shales and sandstones of this formation, the only rocks laid bare being the black slates which immediately underlie XII. It is among these shales that the ores supplying the

Henrj Clay and Greenyille foroaoes are found. These ores ooonr in three different bands, which are in general included in a section of 20 and always within 80 feet.

The upper or eaatUe vn, the most nniforra in thickness, varies from 8 to 15 inches, and having but a slight covering of shale, has been less protected than the lower bands from atmospheric agencies. It is therefore usnally fonnd in a decomposed state, the whole bed sometimes presenting the condition of a fHable shaly oxide, much valued on account of the ease with which it works. Occasionally it occurs in nodules merely encrusted with the oxide, the nucleus being in the original state of proto*carbonate.

neath this, 8 or 10 feet, we meet with the middle or roeJb vein generally 8 or 10 inches thick, though varying from 4 inches to 3 zeet. This is for the most part compact and undecomposed, more uniform in character than tne other veins, and in general rich and fine grained.

Below this, at a de]>th of about 8 or 10 feet is the lower vein varying from 2 inches to 6, and averaging 4 inches. This is usually coarse and siliceous, and chiefly valuable at the outcrop, where it has been decomposed. All these ores contain vegetable impres- sions.

On the Eingwood and Morgantown road, miles from the for- mer place, the conglomerate of the eastern eide of this axis is ex- posed. The Laurel Hill is here not more than 1 or mile in breadth, and on its summit irregularly denuded into small vallies, the hills being capped by the conglomerate in large masses, and the top of XL slightly exposed in some of the valleys.

The conglomerate of the western side of this axis crosses Cheat river not far to the west of Quarry run, and continued southwester- ly, shews itself on Deckers creek at the mill, passing at a very abort distance to the east of Clear's furnace. The limestone (XL) of the western side of this axis rises above the surface i of a mile east of the mouth of Quarry run, and displays itself boldly at the mouth of Scott's run. It is also exposed on Decker's creek, one mile above where the stream leaves the conglomerate. The lower 6 or 8 feet is of a light grey colour and very pure; above this, as far as in view, it is impure and slaty. 8till higher up on the creek, the lime- stone of the eastern side of the axis is extensively exposed.

Ibon Obes on DEoms's Creek. — The ores met witli above the conglomerate on the western slope of Laurel Hill, and of which use is made at Mr. Clear's furnace on Decker's creek, may be considered as occupying two general geological positions, and will be treated of as the lower and upper groups of ores.

Lower Group of Ores. — In the lower part of the shales un- derlying the lowest coal seam, two bands of iron ore occur, ench about a foot in thickness, and separated by about four feet of shales. This ore from its slight protection is generally in a decompose<I state, consisting chiefly of peroxide of a loose shaly texture, and therefore the more easily worked, along with which a nodule of the original carbonate is occasionally found. Beneath the lowest of

these two beds of ore is a white sandstone, 4 or 6 feet in thickness, and beneath this is a third bed of ore, generally 6 or 8 inches thick, which, having been defended by the overlying strata, has escaped decomposition, and displays its original character of a compact proto- oarbonate. A few inches below this in the shales, a fourth band ocoars, 4 inches in thickness. Below thi separated by shales of unknown thickness, probably not more than 8 or 4 feet, occurs a band of limestone 5 feet thick, portions of which are quite rich, but the principal mass impure. From this stratum is procured the flux used at the neighbouring furnace. This group of ores occurs very extensively on the western side of Laurel Hill, where, owing to the gentle dip of the strata, being at about the same angle as the slope of the surface, these bauds present themselves over a wide area on the western flank of the ndge, where they have been traced for many miles. As would be expected, owing to infiltrations from above, the ore at the bottom of the hill is generally richest.

Uppbb Gboup of Obes. — These ores occur much higher in the series, bein above the second seam of coal. They rest upon a lead coloured siliceous and argillaceous sandstone, and are overlaid by siliceous slates of the same colour, which being the first rocks of this kind met with above the second seam of coal, may serve as a land-mark in searching for the ore. This ore is very variable in thickness, usually occurring in large nodules, sometimes fine grained, though generally coarse and siliceous, occasionally so much so as to resemble a coarse sandstone rather than iron ore. Indeed it fre- quently gives no indication of the presence of Iron until after burn- ing or long exposure. Like the ores of the lower group, it is ex- plored over a wide area, being found within a short distance of the surface from the base of the hills to their summits.

Section Vl

OPERATIONS or THE SUBVET IN THE REGION WEST OF THE GREENBRIER RIVER AND IN THE VALLEY OF THE KANAWHA,

Chafteb 1.

Eoel'9 ir\fcrior to the Coal Meaiure$ in Meadow Mountain, Little

Sewell, Ac,

Under a former bead a general account was given of the extent and position of the limestones, shales and sandstones of formation XL, as they are widely developed along the eastern margin of the coal region in Pocahontas, Greenbrier, Monroe and Mercer coun- ties.

In no part of the state are the effects of denuding agencies more strikingly evinced than in the district here referred to. The wide tract occupied by formation XL, instead of presenting along its west- em boundary a regular escarpment composed at top of the conglom- erates and sandstones of XII., is here intersected by deep and long valleys connected with the waters of Greenbrier and New riv-

ere, between which arise lofty knobs and broad ridges, crowned by the conglomerate at their highest points, and which, encroaching upon the intervening valleys as we trace them towards the south- west, coalesce to form the Great Flat Top mountain south of the New river.

The Little Sewell, Meadow mountain and Eeeny's Knobs, are composed for the greater part of their height of the shales and sand- stones of XL, containing near their npper boundary a thin band of siliceous limetone, and capped, as already mentioned, by the con- glomerate. All these rocks, with some undulations, display a pre- vailing gentle dip to NW., and underlie the strata of the Big Sewell mountain. The latter consisting of shales and sandstones, differing from those of formation XL, and containing several important coal seams, appears to owe its peculiar characters to a remarkable ex- pansion of the strata of XIL, here including, besides the usual con- glomeritic beds, numerous strata of slates, shales and sandstones, the latter often of a pinkish colour. As before remarked, additional investigations are required, especially in the vicinity of the New river, to ascertain the true extent and character of this intermediate formation, and for the present, therefore, no decided opinion can be gif en in regard to these particulars.

As an important preliminary to these farther enqniriee, the altitudes of many of the principal knobs and ridges of this region have been ascertained by observations with the boiling point ther- mometer. Among these are the Big and Little Sewell, Meadow mountain, Eeeny's Knobs, and the Blue Stone and White Oak moun- tains. By continuing these measurements, and connecting them with observations of the dip and character of the strata, I feel no doubt of being enabled clearly to elucidate every remaining obscuri* ty in regard to the geology of this tract. The interesting question relating to the great expansion of the rocks underlying the coal of the Kanawha valley, acquires peculiar importance from the considera- tion that from these strata there is every reason to believe are de- rived the saline ingredients which enrich the numerous salt wells of that enterprising and prosperous region.

Chaptkk 2.

Sketch of the Coal Seams and other strata along a part of the

Kanawha Valley.

Not designing to enter into details with respect to the coal re- gion lying west of this tract, and traversed by the Great Kanawha, in much of which our researches have not yet been completed, I shall merely present a few statements descriptive of the position and characters of the coal seams and their accompanying strata as developed in the lofty and liberally productive hills which bound the vaUcy of the Kanawha between the falls and Charleston.

It will be seen from these details that for a distance of nearly 80 miles, viz : from a point a few miles below the falls to Charleston, all or several of the coal seams lying beneath the black flint rock

formerly alluded to are to be met with in the alos of the loftj hills on boUi sides of the river. So great a prolongation of expos- nres, displaying the same division of the coal series throoghoat, could not have existed but for the fortunate occurrence in this tract of two broad undulations or axes, retaining the strata above the level of the river, when by a continuance of the original northwest- em dips as displayed in the neighbourhood of the falls, they would have been carried entirely out of view within one third of the dis- tance along which they are now exposed. The first or most east- ern of these undulations is seen to commence in the neighbourhood of Hughess creek, the strata changing from their northwestern dip to the horizontal, and then rising as they extend westwardly, so as to present a southeasterly dip.

This dip continues to the hill between Keller's (Kelleys, £d.) and Witchers creeks, where it is succeeded by a gentle inclination to the northwest, which in a short distance is followed by a restoration of the southeasterly dip. The latter inclination continues to the Burn- ing spring, gradually elevating the strata so as to carry the lower coal seams to some height up in the hills, after which the counter-dip to NW. reappears, and continues down the river to within about 10 miles of the Ohio.

The following details relating to a few localities will serve to convey a general idea of the positions and characters of the several coal seams and accompanying rocks as they are exposed to view along this magnificent natural section.

Tlie numerous analogous details already collected, together with various researches yet incomplete in regard to the topography as weU as the geology of this valley, will, it is hoped, hereafter enable me to present a full delineation of its structure in the accurate form of measured sections throughout its whole extent, while the chemi- cal details relating to its siuines now under examination, as well as those connected with its coals snd limestones, of which a partial re- port will be made in the sequel, will completis the interesting scien- tific labours devoted to the development of its resources.

The hills on each side of the Kanawha, in the neighbourhood of the falls, are made up of coarse sandstone and conglomerates at the base, with an alternation of yellow shales and slaty micaceous sand- stones. Immediately in this vicinity no coal is to be seen, but in the more lofty dividing ridges, back from the river, it shows itself at various places, among which are the vicinity of Scrabble creek on the north, and Cotton and the other high hiUs on the south side of the river.

The conglomerate forming the lower strata for upwards of three miles down the river, disappears at the termination of that distance, giving place to the overlying micaceous sandstones. About tiye miles below the falls two coal seams make their appearance, but neither have at this point been worked. The upper of these is, however, more favourably exposed for working, and is accordingly opened near Mr. Huddleston's. It crops out a short distance up the creek about 120 feet above the base of the hill. It is a compact lua-

troas coal oyerlaid by a pretty heavy bed of blae shales, and resting on yellow shales, neither of which contains many fossil impressions. The lower seam, about 90 feet below this, is thinner, and the coal is not so good. The shales above it are extremely thin and frag- mentary and full of indistinct impressions, principally ferns, &c. These bills were found to be about 700 feet in height, profusely strewed at their base with fragments of the black flinty rock found near their summits, and which will be described hereafter. Two or three miles further down the river both of these coal seams, as well as the entire structure of the hills including them, are more favourably exposed at Smither's creek and Ryder's creek.

SmUher*s Creek.

The lowest coal seam is seen to crop out a short distance up the hill from the road side, just before reaching the creek, and has been partially opened. It is about three and a half or four feet thick, good coal, roofed by thin bluish shales and underlaid by yellowish ales. It is also worked about half a mile up the creek.

The next and most important seam is opened about 100 feet from the road up the hill, and is much thicker than the former: it is identical with the high seam found near Huddleston, is upwards of six feet in thickness, and includes three bands of black bituminous shales, the lowest of which is about twelve inches thick. The shales over the coal are compact and blue, remarkably free from vegetable impressions. Those below are yellow, and contain culmiferous and arundinaceous plants. Above this seam there are appearances of two other seams. Their tails are, however, extremely thin, and little attention has yet been bestowed upon them. About half a mile below the creek the main seam has been extensively worked by Mr. Stockton, and also below at Ryder's creek by Mr. Hervey. The following sections will furnish a knowledge of the structures and relations of these coal seams.

Section at Stockton's steam mill half a mile below Smither's creek, commencing at the lowest stratum :

1. Grey Mica, shales and slaty sandstones.

2. Grey shales.

8. Limestone, compact bluish grey, fossil, stems, &c., two feet eight inches.

4. Yellow shales.

5. Karrow seam of coal.

6. Yellow micaceous sandstone.

7. Yellow shales, containing impressions of culmiferous and arundinaceous plants embedded obliquely in the mass.

8. Fine clay, yellowish grey, extremely plastic and tenacious, two feet.

9. Coal seven feet, containing three seams of slate, lowermost one foot above tlie floor of the coal, about three inches thick.

10. Blue shales, containing but few impressions, and those of stems principally, and disseminated masses of argil, iron, &c.

11. Slaty Bhalee and micaceous sandstones.

12. Goal shales, and traces of a very thin seam.

13. Moderately coarse grained sandstone.

14. Brownish shales and slaty sandstone.

15. Traces of ooaL

16. Bluish calcareous shales, few impressions, shells, &o.

17. Black flint rock disposed in laminn from four to ten inches thick, seven feet thick.

18. Coarse grained yellow sandstone, helow in heavy heds, above more slabby. This latter constitutes the capping of the hill. The general dip of the rocks is pretty uniformly to KW. about 2°.

Ryder's Creek,

A similar section, made at this point, presented precisely the same order of stratification, but in consequence of the dip carrying out of view some of the lower rocks, the lowest stratum nere, on a level with the road, consists of the yellow sandstones, which im- mediately repose upon the narrow seam of coal below the principal seam.

The principal seam is by the dip brought lower down in the hills, and is opened at several points by Mr. Hervey. It agrees in structure with Stockton's seven foot seam, with the exception that the thickness of the lowest band of black slate is increased to about fifteen inches, so as to leave not more than five and a half feet of good workable coal.

The limeBione which is referred to above as being low down in the order of formation, and which is well exposed near the steam mill, with its rounded and reddish weathered surface, should be re- garded as one of the most important beds which has heretofore es- caped attention. It is traced down the river for a short distance, when it sinks out of view, but probably again makes its appearance in the vicinity of or below Hughes's creek. Masses of it are seen in the bed of the creek, evidently derived from a stratum near at hand. The peculiar appearance of the weathered surface of the rock, will always enable the observer to identify it. It is coated with a buff brown ferruginous oxide, giving it the aspect of iron ore. Of the hydraulic character of this and some of the other limestone bands of this region, some account will be given in the sequel.

The yellow shales which are found immediately below the heavy seam of coal and the upper portion of which presents all the char- acters of a good fire-clay, is the next remarkable formation in this region, not only on account of its value in the construction of fur- naceSf but also on account of the great number of impressions of culmiferous and arundinaceous plants which it contains, many of which are enclosed in an oblique direction in the stratum, so as to present a less flattened form than when they repose comformably m their bed. These shales contain also disseminated, flattened and kidney shaped masses of argillaceous iron ore, but not in suffi-

oient abandance to render it valuable in an economicnl point of view.

Black Siliceous JRoehj Flint or Bbmstone,

This remarkable deposit which here appears of the thickness of seven feet, and at an elevation in the hills above the road at Ryder's oreek of 466 feet, may be traced by its debris from near the fdls, and seen capping the hills in broken masses at the head waters of Scrabble creek. It is fonnd op the Gauley river on the NW. side, forming the tops of the hills, but cannot be traced in this direction above Twenty Mile creek. Thence it proceeds with a general gentle dip to the NW., and is found up all the creeks flowing into the Kanawha river. At Smither's, Ryder's and Hughes's creek it occu- pies a considerable elevation in the hills, being overlaid by a coarse sandstone, which, as low down as Keller's (Kelley's, £d.) creek, is found to be a conglomerate. It is readily distinguished from all the associated strata by the resistance which it furnishes to disintegrat- ing agency ; and by its always presenting a regular bedding and a angular sharp structure. No fossils can be detected in it, but at Ryder's creek the blue shales upon which it reposes are observed to contain a few impressions of shells.

Although throughout, the structure of this rock is remarkably uniform, sometimes it assumes the character of a black siliceous shale, particularly in its lower portion. And above it is so dense and vitreous as to be readily mistaken for true flint, and properly entitled to the name of hornstone.

irughes*8 Creeh

Up this creek about of a mile, and also on the mdn road, the principal seam of coal has been opened at the former point by Mr. Boasman, and at the latter by Mr. Childers. At both of these places it presents the same characteristic. Blue shales, compact, and but little fossil in the roof. Here, however, the included shales are thicker than at Stockton's, snd the quantity of coal is in conse- quence diminished. The whole seam, including shales, is above 6 feet thick. The bed of Hnghess creek contains masses of limestone, as before noticed, but no stratum of this rock has yet been found in place. At this point, as observed, a synclinal roll has occurred, which, about a mile further down the river, has brought up the lower seam, which is now mined by Mr. Morris Hansford.

This seam is abctnt feet thick, is roofed by sandstone at one point, and a thin band of bluish shales at another. The coal is compact and lustrous, and the overlying shales very fossiliferous. Beneath, the shales are yellow, and contain a few impressions. This is undoubtedly identical with the lowest seam observed on Smither's creek, which passes out of sight near Stockton's, and again rises near Hughes's creek. The sandstones above this seam are about 60 feet thick, and have reposing upon them a thick bed of yellow shales. Then follows the main seam of coal which has been only

partially opened, bat saffieiently to identify it with the Stockton seam.

Above these seams two others have been observed, before reach- ing the black flinty which here attains an elevation of at least 400 feet, and still preserves its thickness of 7 feet. It is here, as at Ryder's creek, overlaid by coarse grey micaceous sandstone.

The lower or 4 foot seam, as it is called, is opened in no less than 9 different points nearly opposite the month of Keller's (Kelley's) creek, by the Messrs. Hansford. The direction in the line of dip is admirably marked out by the beavy bed of sandstone which overlies It, for here, as above, this seam has but a very thin roofing of shales. The continuity of the seam in this neighbourhood is intermpted by an abrupt roll attended with a slight dislocation, causing the sand- stone to pitch suddenly down to the NW. at an angle of 6% and cutting out the coal for the distance of more than of a mile above. Where this occurs, the seam is very much twisted, and portiona of it included between the laminsB of the sandstone.

Keller's {Kelley's) Creek,

The same seam of coal which has been opened by Mr. Hansford on the opposite side of the river, appears here lower down on ac- count of the dip, and is worked at two points by Mr. Fry. Here the shales over the coal are somewhat thicker, but much less impressed with fossil plauts. Although the tails of the seams above this are to be seen by careful inspection, yet no opening has been made of any of them. It will be borne in mind that this seam and all the strata dip to the NW., i. e., down the river, and that as you proceed in that direction, all traces of them are soon lost, so that none but the higher, and here much thinner, seams are ob- served, one of which, the 4th, has been partially opened for domestic purposes. As you approach within a short distance of Witcher's creek, you observe a change to have occurred in the dip. This, though not discernible on the hill sides near the road, owing to the confusion of structure resulting from extensive slides, is readily re- marked some distance back from the river, presenting a gentle roll which brings the 8d seam of coal into view a little above the road about half a mile east of the creek. This seam has been partially opened by colonel Joel Shrewsbury, dipping at an angle of about to S£. It is about 8 feet in thickness, has resting upon it heavy beds of argillaceous shales, crowded with vegetable impressions. The shale is of a light grey drab colonr, while the impressions are of a distinct brown. The tail of the next seam under this is noticed near the surface of the road a little below Witoher's creek, and it and the overlying seams dipping to the SE. make their appearance at different elevations in the hill side. This southeasterly dip contin- aes to the vicinity of the Burning spring, where, as already de- scribed, the northwestern inclination is restored.

For a distance of several miles above and below Witcher's creek, the number of coal seams indicated by the outcrops on the hills is

such as to prove a subdivision of the two or perhaps three lower seams by the interposition of thick bands of slate. Among the illus- trations of the changeable character of the seams in this neighbour- hood may be mentioned the almost entire replacement of the 2d seam by black argillaceous shales and the gradual reappearance of the coal, at first in thin wafery bands, afterwards expanding to a thickness of 8 feet, where opened for the use of Mr. J. Shrewsbury's furnace at the upper salt works. The important seam, hereafter to be described, as extensively exposed and wrought in the \icinity of Campbell's creek, much lower down the river, being actually ob- served to be divided as we trace it eastwards into two smaller bands by the interposition of a continually expanding bed of slate, would appear in the region now under consideration to be repre- sented by at least two coal seams, which, followed still farther up the river, again gradually coalesce, forming at length the massive stratum already spoken of as Stockton's seam.

Of the precise nature of these interesting changes, and the num- ber, position and character of the seams throughout this part of the valley, the accurate tracings and measurements of another season will, I trust, enable me to present a full and satisfactory account. The knowledge now acquired as to the less complex features. of tlje adjoining districts, both above and below, while lading the illustra- tion of these curious peculiarities, will furnish essential assistance in the explorations yet to be made in the tracts remote from the river on either side, in some parts of which, especially on the Elk, a simi- lar multiplication of coal seams has been found to occur.

Vineyard Hill included between George e and CampbelVB Greek.

This hill extends in the direction of the river nearly north and south at this point, with but one interruption, where it is cut down by a narrow ravine called the Thoroughfare Hollow, leading to the creek which flows parallel with the river behind the lowest portion of the hill thus out off. Above, between the Hollow and Georges creek, it attains its greatest altitude, and when covered as it is now with herbage, appears to rise with a uniform but rapid slope to its summit. When, however, the trees are denuded of their foliage, it presents the peculiar aspect which belongs to all the hills bordering the Kanawha from near the falls to the vicinity of Charleston, viz: a terraced or bench -like structure, generally found to indicate the position of the coal seams. Three such terraces are well marked on the side of Vineyard hill, and each of them presents us with a seam of coal and the accompanying shales.

Section of Vineyard Hill in the ascending order.

From the bed of the river to the bottom of the lowest coal seam is 54 feet. The four or five feet of the lowest portion of this height is made up of gravel and water worn pebbles of many of the older rocks which have been transported from the east. Among these are

'I

oooasionallj foand not only the rooks of the Appalachian reon, but also the chloritic, epidotic and granitic rocks of the Bine Ridge. Resting npon this, particularly in the vicinity of the salines, is a of yellow argillaceoas and sandy clay used in the manufacture of brick, and reputed to be of good quality, and upon this reposes the yegetable mould which gives to the Kanawha bottoms their well known fertility. This, including the substratum clay, is from 20 to 25 feet thick.

Above this, and forming the immediate base of the hill, is a grej micaceous sandstone, composed of alternating layers of hard, com- pact and soft fissile rock.

No. 2. Bitumifunu Coal — the thickest and most important seam in the whole series. At Campbell's and Georges creek this seam varies in thickness from 5 to feet. Immediately at the river, and a short difttance up these creeks, it yields 6 feet of coal, including one band of black bituminous shale. It has been opened at several points by Mr. Lewis Ruffner, and in one place by Mr. William Shrewsbury — the seam in the latter instance being reached below the level of the road. Below Campbeirs creek it sinks out of view, and the west- erly dip of the strata continuing, it is not again brought up to the surface. It may be traced along Georges and Campbell's creeks for several miles above their mouths, and is also well developed on the south side of the river, where it is worked by Messrs. Reynolds h Donally, and Noyes, Rimd & Co.

The narrow seam of slate traversing it at CampbelPs creek is seen to increase in thickness as it extends up the river, against the dip, so as to become as much as 8 or 10 inches at George's creek, — and continuing still to expand, it ultimately divides the seam so as to render it necessary to work the upper portions as independent seams.

The coal rests npon a Flaty argillaceous sandstone, crowded with the broken fragments of coal plants strewed promiscuously through the mass, and for the most part lying in an inclined position. This stratum which is included in the measurement of that lying next be- neath, varies at the place of the present section from 2 to 8 feet in thickness. The upper portion of the stratum has the character of a fire-clay.

No. 8. This stratum, which is about 40 feet in thickness, reposes npon the coal, and is composed for the most part of a hluiah drab coloured slaty shale, including an occasional layer of slaty sandstone. Where it is immediately in contact with the coal it is blue and highly bituminous. The slate resting directly upon the coal, includes a thin seam of nodular iron ore in flattened ovoid masses, and presenting tlie concentric structure frequently observed to belong to this variety of ore. This is the heaviest bed of slate which occurs along the whole line of the Kanawha as far down as Charleston. The stra- tum of iron ore assumes in some places above this coal seam the appearance of a ferruginous conglomerate. This is particularly no- ticed to be the case on Campbell's creek behind the Thoroughfare hill. Indeed the whole of the shale at this point presents more of a

f erraginous character than nsual. A thin stratum of compact ore is found a few feet above the coal, and a similar ore below it in the bed of the creek.

Madreporite, — This carious fossil is included in the shale in large spheroidal masses, resembling the nodules or septaria of formation YIII. These masses are highly calcareous, constituting in fact a tolerably pure limestone, and generally found within a width of about 10 feet of . the slate.

Although this section refers particularly to the stratification in the CampbelVs creek series, it may be well to state here that a simi- lar Madreporite deposite is noticed a few feet above the coal seam worked by Mr. Harvey 21 or 22 miles above, and again on BelKs creek. It should also be remarked that the shales which include it at these points contain disseminated masses of lenticular iron ore. Besides its interest in a purely geological point of view, this singular fossil is important as furnishing the means of determining the con- tinuity of one of the most important coal seams in the series, viz : that at Stockton's steam mill and at GampbelPs creek.

No. 4. Bituminous Coal — thin seam, not exceeding 20 inches, reposing immediately upon the shale above described, and found to be remarkably uniform in its occurrence. This seam has not been worked.

No. 6. Argillaeeous Sandstone — Slightly micaceous, light grey, sometimes bluish, disposed in regular laminfe, in thickness from a few inches to several feet, which in some places include thin bands of slaty sandstone. This rock is extensively quarried for the con- struction of salt furnaces. It abounds throughout with fossil plants. Thickness 200 feet.

No. 6. Bituminous Coal, — This seam which will average about feet in thickness, is not opened immediately at this point, but is used extensively lower down the river by the salt-makers, where it is found pretty high up in the hills. Openings have been made in it by Messrs. Bream, Friend, Brooks and others on the north side of the river, and by Messrs. Patrick, Donelly, &c. on the south side. It is distinguished from all the others of the series by the prevailing character of the roof, which is a coarse grained brown and grey sandstone, sometimes disposed in pretty heavy beds, and sometimes slaty in its structure. This sandstone is about 215 feet in thickness, containing in some places, as in Mr. Brooks's drift, irregular nodu- lar masses of compact argillaceous iron ore. This seam is rarely exposed in a distinct manner on the hills immediately facing the river, but in the ravines making up from the river, as for example. Bowman's hollow, is finely displayed.

The coal of this seam is not so black and Ipstrous as the Gamp- bell's creek seam — it is more slaty, and the upper portion contains thin laminas of iron pyrites. It is, however, extensively mined from some distance on the river in the vicinity of Bowman's hollow. Like the other seams in this region, it reposes upon a dark coloured carbonaceous shale or slate, with oblique vegetable impressions. Great diversity is observed in the quality of this seam of coal at the

different openiogs, even within short distance*. Its thickness ib also quite flactnating. At some points, for example, in Bowmans hollow, 40 inches of good conl are obtained, while in the openings at Bridge hollow, lower down on the river, the seam is so rediiced that not more than 28 inches can be procured.

No. 7. Siliceous Sandstone — generally coarse grained, but includ- ing a few bands of a tiuer texture. This rock, as before stated, reposes immediately upon a seam of coal generally without any in- termediate slate. It occurs in beds varying in thickness from one to four feet, is less impressed by organic remains than the sandstone lower down in the series, and assuming the character of cliffs as you descend the river ina NW. direction, becomes lower and lower in the hills until it ultimately sinks below the bed of the river near to Charleston. Thickness 215 feet.

No. 8. BituminoMM Coal, — This stratum of coal, which is the high- est in this part of the series, has not been opened in Vineyard Hill or at any point above Mr. Daniel Ruffner's on the north side of the river, and Faurers salt furnace on the south side. It is, however, always seen resting upon the last described sandstone, with a thin bed of intervening shales. It is generally easily found by tracing the overlying flint rock, beneath which it invariably occurs. This seam will average about four feet in thickness. The coal is rather inferior to that of the lower seam, being of a harder and more slaty structure, though presenting various degrees of purity at differ- ent localities. At Mr. Daniel Kuffners a thin band of siliceous, slaty sandstone intervenes between the coal and flint rocks, but lower down this thins out and the roof is composed entirely of the flint, and so continues until its final disappearance under the bed of the river below Charleston.

No. 9. Siliceous Roeh Blue or Black Flint — This sinpar de- posit, which has already been described, comes next in order. On account of its definite character, it proves to be a v:iluable guide in tracing the accompanying formations, amid very considerable local undulations, enabling us to determine their true position and their dip. In the place of the section it is seen of its average thickness, a little exceeding 7 feet. The upper portions are nearly black, compact and vitreous in texture, and are properly deserving of the title of Hornstone. The lower are more slaty, and of a blue colour. This deposit, while it preserves throughout its siliceous character, as it extends in the direction of the dip, becomes more slaty in its structure, until in fact it passes into a true siliceous slate, reposing immediately upon the last mentioned coal seam. This is the form under which it appears at Mr. Faurer's coal bank a short dis- tance above Charleston. The siliceous shales or slates immediately resting on the coal, gradually pass into a more compact slate, and finally into siliceous rock. The stratum is here about 7 feet in thickness. As seen in the section, this formation is covered with a thin band of impure iron ore, in kidney shaped masses, em- bedded in sandstone — the whole thickness not exceeding 4 inches. Further down the river the iron disappears, giving place to fer-

mginous shales and sandstones, which Imiuediatelj overlie the silioeoas rocks.

No. 10. Resting on the above, there next occurs a heavy bed of yellow coarse silioeoas sandstone, argiUaceous in some bands, and quite prone to disintegration. This is sarmonnted by a more sili* ceoas band of the same rock, occasionally qnite cellalar, and include ing fossil impressions of shells, Encrini, &c. This band contains a notable portion of lime. Thickness 140 feet.

No. 11. The section of Vineyard HiU is terminated by a thin cap- ping of aboat 10 feet of reddish and yellow shales, the lower por- tion of which contains disintegrated masses of argillaceons iron. This may be regarded as the commencement of the series of shales, which along with shaly sandstones and thin calcareous bands, over- spread nearly the whole of the tract lying between Charleston and the Ohio at the month of the Kanawha, presenting for the greater part of that distance a nearly nnintermpted, but very gentle dtp towards the NW., then becoming horizontal, and finally near the Ohio rising with a counter dip and forming the middle portion of our great western coal basin. These strata, all higher geologically than the fiint rock, and containing two or more coal seams where penetrated by the Ohio, constitute in this region what was formerly described as the upper coal uries.

SECTION VII. OPERATIONS or TEE SVRVET IN TEE NORTHWESTERN DISTRICT,

Oar investigations in the extensive and highly interesting por- tions of the state referred to under this head, were for the most part of a preliminary nature, being chiefly directed to the determination of certain general features oi their geology which might serve as useful guides in conducting our future explorations.

Referring to the sketch formerly given of the ontlines of the great coal region, it will be remembered that the boundary of this tract towards the north is marked by a broad and gently inflected curve, crossing from Ohio into Pennsylvania, some distance north of the most northern part of Virginia in Brooke county ; and that as it ex- tends eastwards, this line gradually sweeps around so as at length to assume a southwesterly direction along the western slope of the range of highlands known in Pennsylvania as Chestnut ridge, and in Vir- ginia as Laurel Hill. From the general description included in the sketch referred to, it will at once be seen that the lower coal aeries must occupy that portion of the basin lying adjacent to this margin, while the upper will be found overspreading a zone more towards the middle of the trough ; and that the dip of the strata, unless where modified by merely local causes, will conform to that of the corre- sponding ports of tlie margin, being southerly towards the northern, and westerly towards the eastern limits of the basin.

Setting out with this general view of the structure of the basin,

onr first object, and that to which attention was chiefly directed during the past season, was the tracing of the two great groups of strata, the lower and upper coal series from the Ohio around to the Monongahela, and in a southwesterly direction parallel to the course of Laurel Hill, and in marking the liuiits of these groups hy sections from the Ohio to the outcrop of the lowest strata of the coal meas- ures some distance to the east of Morgantown and Clarksburg.

By these examinations the general outlines of the tracts occupied by each of the two great groups, and the important changes occur- ring in their component strata as they are prolonged towards the south, were in a general way ascertained, at the same time tliat numerous observations of a more detailed nature, accompanied by measured sections, were made at several important localities.

In tlie present stage of our enquiries regarding this region, it would obviously be premature to attempt giving any details relating to its geological features. Its general outline and structure have been described in sketching those of the entire basin, under a pre- ceding head. Of the high economical importance of large portions of this area the fullest evidence has already been attained, nor can it be doubted that the systematic explorations to be resumed at the commencement of the coming season, will contribute in an important measure to the knowledge and practical development of its ample resources.

Of the composition of several of the iron ores, coals and limestones of this district, some details will be found in the concluding section of the report, to which I now proceed.

Section Viii. Chemical J>Etail8,

The following details relating to the chemical composition of some of the more valuable materials appertaining to the various dis- tricts referred to in the present report, will be introduced in the order in which the geological descriptions have been presented, be- ginning with the tertiary marl and closing with the coal, iron ores, and limestones of the great western coal field. After what has al- ready been remarked, it is needless to say that they constitute but a part of the whole body of chemical results hereafter to be given to the public in systematic shape, and are presented now chiefiy as illustrations of the preceding sections of this report.

Chapter 1.

MiocefU Marls of the Distrust South of the James riter.

In drawing up the following tabular view of the amount of car- bonate of lime contained in the marls of this portion of the state, it will be seen that I have included a number of results published in

former reports, sb well as sucb as have been obtained by more recent examinations. Such a comprehensive table, including nearly all the important localities soath of the James river, will, it is thought, serve a useful purpose by bringing into one vIdw almost every va- riety of marl met with in the district, and seems to be rendered par- ticularly desirable by the fact, that from the Inconvenient form and small edition of preceding reports, but few of those who feel inter- ested in such results, have ever possessed or now retain copies of the publications in which they were made known.

ZoeaUHet. Ohurtationa. Carh. Linu,

IsLZ OF Wight.

Mr. U. Day's, Perfect Bhells and fWrncnts, sometimes

cemented, green sancTa trace, 76.1

do. Ferruginous rock marl, semi- crystalline,

ffreen 8and a traoe, 77 .2

Mr. Saunders's, (2a stratum)— yellow small IHable fhiir-

ments of shell, considerable green sand, 48.8

do. (dd stratum) ditto, 60.2

do. ditto, 42.0

James Pedin's, Light, shells entirely decomposed, nodu-

hir, reen sand a trace, 64.5

Day's Point, Blue, triable, micaceous and sandy, 7.9

G. Purdio's, Shells and nagments in a light tenacious

clay, frequently rich in indurated casts of the cbama, green sand a traoe, some- times a fragmentary conglomerate, 71 . 6

do. ditto, 62.6

do. Conglomerate, ditto, 81.8

do ditto, 68.6

Mr. White's, A conglomerate of pericct shells and frag- ments, ferruginous and semi-crystallin'o,

very compact, 91 .3

Mr. S. P. Jordan's, Ycry comminuted iVagments of shell in a

ferrujous sand, green sand a trace, ... 68 .4

do. dStto. 79.6

Merit Todd's, Light, rather tenacious, shells decomposed,

green sand a trace, 28.4

do. A conglomerate of small shells and frag

mentB, intermixed with a ferruginous

sand, tinged with green sand, 42.0

Bocks, Blue, arenaceous, very friable, containing

a few small cythereas, 79.5

Mr. Booth's, Of a ve

do A coarse phelly conglomerate, yellow, oo-

casionally a cast ottbe chama, 78.4

f a very light yellow colour, containing small rragmentd, frequently cemented,.. 64.7

do Shells decomposed, concretionary, 71 .5

John T. Mason's, Macra modicella in a yellow sand, with a

few other shells and fragments, green

sand a trace, 86.2

Naksemond.

Town Point, Ferruginous, consisting of small shells and

finigments, 67.5

2 mils above town Point, mtto, 62.8

Mr. Keeling's, Small shells and fragments in a light sand,

also frugments of the pecten, sometimes conglomerated, 76.0

LoeaHUst. Ob$erffaiUm$. Carb.

Mr. Keeling's More ferroginoiui, containinfr fewer sheUs. SO .

Below Dumpling Island, . A oonglomerate of fragments, quite com- pact, 85.2

do. . . Finely comminuted shelly matter, deeply

tinged with iron, VI. 6

BCr. Cowper'B, Ferruginous, consisting chiefly of flne iVag-

ments, 72.7

Near Suffolk, ditto, ditto, green

sand a trace, 17.0

Upper shore ofNansemond nver (near the mouth),. Small fragments of shell, with perfect

shells intermixed, ferruginous, 82. 9

Point above Sleepy Hole

ferry, Principalljr chamas and crepidulas, inter*

mixed with yellow sand, 43.2

Near Suffolk, Blue, containing finely divided shelly mat- ter, 22,7

Upper shore (near Sleepy

Lole ferry), Blue, containing fine and coarse fhigroents

of small shells, 80.6

Col. CorhclPs, Small fragments of shell, ferruginous, 62 . 5

do ditto, 76.2

Maj. Crocker's, ditto, 64.7

do ditto, 28.0

W. II. Goodwin's, ditto, 68.4

Mr. Phillips's, ditto, 80.6

Near Chucatuck mill, ... . ditto, 82.9

Subbt.

Mrs. Faulcon's, Yellow, consisting of decomposed shells

and fragments, ooeasionally slightly ce- mented, 64.5

8 or 4 miles above Four Mile tree, Fragments of shell in a white sand, slight- ly intermLxed with green sand, 47 .2

do. A yellow conglomerate of shells and casts. 78.4

Near Four Mile tree, Fragments of shells and undcoomposea

shells, 88.6

Mr. Organ's — Clermont, . . Yellowish white, fine and friable, occasion- ally concretionary 71.5

Wakefield, Light, shells generally decomposed, a few

fragments in a white sand, green sand a

trace, 51 .1

do Blueish, shells very much decomposed, .. 76.0

Douglas's, White indurated casts of chamas, 87.5

Clermont (river shore),. . . Blue, larg<%ly intermixed with green sand,

shells finely decomposed, 10 .2

Upper Chi poke creek, A calcareo-siliceoua conglomerate, very

compact, containing fragments of poctens and casts of pemas, 65.6

Stith's, Small fnurments of shell in sand, a good

many chamas, quite richly specked with

green sand, 42.0

do ditto, 83.0

Biver shore {above tlie Consisting of fragments of the choma in a mouth of College creek), light sand, 44.3

A. C. Jones's, Shells and fragments in a light sand, inter- mixed with green sand, 53.2

LoeeUiiUi. Obaervaiiona. Garb, Urns,

Booth's mill; Terrapin creek, Yellow marl, mactra mod. almost exclu- sively, sandy clay, with a little green

sand, 82.7

Joseph Pretlow ; Terrapin nm, Yellowish grey marl, mactra mod., sili- ceous sand, with a little green sand, 22 . 8 Blackwater, near Wall's bridge, Mactra mod. in a yellow sandy clay, con- siderable green sand, ,. 87 .0

South AHFTON.

Nottoway swamp, one mile from mouth, Massen-

burg's mill, Bluish grey marl, shells, chiefly venus,

much decomposed, in a siliceous clay,

with much grcen sand, 48.8

Six miles SE. of Jerusa- lem, Mr. Massenburg's, Yellow fraffmentaij marl, with small

shells often entire, but water-worn, chiefly mactra mod., plicatula, mairinel-

k, 86.4

Monroe, on Nottoway

river, Bluish grey marl, containing chama, as-

tarte, voncricardia and Iragments of pecten, in a siliceous clay, with green

sand, 87.8

Blackwater river, one and a half miles noith of Lea- cock, Mr. Bering, Yellow marl, shells in great variety, chiefly

mactra mod., turritella, ostrea, chama, crassatella, in a sandy clay, with consid- erable green sand, 80.0

Nottoway river, above

Monrcw, Blue marl, shells, mactra mod., ostrea,

turritella, etc., in a sandy clay, with a

good deal of green sand, 85.2

Same locality, % . . . ditto, 20.0

Blackwater river, above mouUi of Black creek,

Mr. Lawrence, Light brownish grey, shells, mactra mcxi.

almost entirely in an adhesive clay, with

a little green sand, 29.0

Same locality, ditto, 20.0

Two miles WW. of Frank- lin, Dr. Bowers, Mottled brown and grey, shells, ostreas in

a soft decomposing state in a siliceous

clay, with a httle green sand, 40.5

Br. of Terrapin Swamp, Bo. Pretlow, Blue marl, shells entire, and almost exclu- sively mactra mod., 18.2

Blackwater river, above the mouth of Black

creek, Mrs. Ely, Grey marl, mactra mod. in clay, with a

considerable amount of green sand, 20.6

Nicholson's mill, Mactra mod. in a yellow sandy clay, sandy

residuum, with a trace of green sand, . . 22.0

UtQOT ]EUdley'B, Dingy yellow, tenacious, shells entirely

decomposed, sandy residuum, green sand a trace, 29.0

LoealitUi, OUaertoHom. Oarb. Lkns,

M%jor Ridleys Indurated nodular marl, shells decom- posed, sandy residuum, green sand a

trace, 51 . 8

Capt. Briggs, Large shells and fragments in blue sand,

a trace of green sand, 88.4

do Compact lump marl containing casts and

impressions of shells, green sand a trace, 61 .4

Mr. Ivey, Perfect shells in a yellow sandy clay, a

trace of green sand, 86.1

Blackwater, nearly oppo- site mouth of Burke's

run, Mr. Bowden, Yellowish brown cemented marl, siliceous

with a very little green sand, upper part

of the bank, 79 .0

Mr. Bowden, on a run making into tlie river, . . Bluish green marl, shells in considerable

variety, chiefly mactra mod. with turri- tella, natica, c. , much green sand, 81.8 Above Broadwater bridge, Mr. Urquhart, Yellow marl, shells, mactra mod. exclu- sively, green sand, 27.8

Benj. Drew, near the Sus- sex line, Light grev marl, somewhat chalky sheila

much aecomposed, consisting chiefly of

mactra mod., 46.1

Two miles NW. of Frank- lin, Dr. Bowera, Yellow sandy marl, shells much decom- posed, consisting chiefly of mactra mod., 16 .0

NoBTH Carolina. The following two specimens, though from

localities a little beyond the limits of the state, are included in the table, by way of shewing the extension of the blue and yellow marls into Carolina. Mr. Wood's, a little west of the Meherrin river and south of the state

line, Yellow marl, shells, mactra mod. , Incina

<&c., in a mixture of yellowish sand ana

clay, a trace of green sand, 45.4

do Blue marl, shells chiefly mactra mod. in

bluish clay, a good deal of green sand,.. 80.7

Sussxx.

Col. Blow's, Upper stratum, mactra mod. in yellow

sandy day, green sand a trace, residuum

femiffinouB sand, 86.8

From uie calcareous portion of the grey marl, dingy white, indurated, consign-

ble green sand. 68.6

From the middle of the grey marl, no shellsj occasional fragments, a mixture of white and green calcareous sand, 81 .8

Wm. H. Pegnim, Mactra mod. in olue tenaceous sandy clay,

residuum sandy, 28.1

William H. Pegram, Chin-

quaoin Bun, Sandy residuum, oraen sand a trace, 85. S

ao. Mactra mod. in yellow tenaceous day, con-

siderable green sand, residuum sandy ,. . 88 . 0

LoeaUtiM, Ob9er9aHona, Carb Urns,

Col. Gee, I>ingy yellow, oomminutcd IVBJcments of

fibellB in a clayey Band, green sand a

trace, 42.9

Henry Birdsong, Mactra mod. in a blue tenacioua clay,

sandy residoum, green Band a trace,. . 1 . 80 .5

do. Maotra mod. in yellow tenaoeous clny,

sandy residuum, considerable ffreen sand, 82.7 Miy. Pacham'fl mill, Mactra mod. chiefly, in a blue clay, alumi- nous residuum, a trace of men sand, . . 89.0 Mrs. Blunt, Corapoct and indurated, lignt grey, con- taining casts of sheils, residuum cniefly

green sand, 79.7

do Great variety of perfect shells in a blue

sand ; sandy residuum, considerable

green sand, 80.8

Mactra mod. in blue sandy clay. A trace

of green sand, 81.8

Mr. Mason's, indurated lump marl; bluish grcv, con-

taimng easts and imprensions ot shells

and a trace of green sand, 70.4

do Comminuted frasents of shells in blue

sandy clay with perfect shells ; a trace

of green sand, 60.4

Harrison's mill, Average character of upper marl, bluish

white sheila generally deoompoeed 57 . 9 do. Lower portion of the bed, compact indu-

rated lumps witli casts and impressions

of shells, 69.0

Pbikob Geobob.

Coggin's Point, Bmall shells and fragments in a yellow

sand, green sand a trace, 28 .4

Mr. Prentice's, A great variety of shells in sand, 63 . 6

Evergreen, Fragments of shells in a light sand, 82.9

Tarbay, ditto. 19.4

Mr. Bryant, Indurated lump marl, dingy colour, con- taining casts and imprrasions of shells

and small fragments, none perfect, 61 . 8

do Deep yellow, perfect shells contained in

very comminuted fragments, sandy re- siduum with a trace oi green sand, 20.9

M. 8mith, Lower portion of the marl, a conglomerate

of small bivalve shells, chiefly chama congregata— considerable green sand,.. 68.6

do Upper portion consisting wholly of mactra

mod. in a blue clay, green sand a trace,. 86.0

Gsesksville.

Mr. Seevc's, Large shells and frajenta in blue sand,

a largo number ot tiie genus bolanus, green sand a trace, 28.6

Chaptkb 2.

LimestoneB asaociaUd with the Mieaceatu and Talcose Rocks of the

Southern District,

Under a former head, mention has been made of the highly mag- nesian character of some of the limestones here referred to. The details which follow will serve to shew the yariable composition of

these rocks as procarcd from different localities, and at the same time will fully sustain what was formerly asserted of the value of the lime which some of these beds are capable of famishing. Of the hydraulic character of certain varieties, some notice is taken be- low, and additional and more prolonged trials remain yet to be per- formed. Until these are completed, no confident affirmation can be made of the great excellence of any of these limes as water cements, though with regard to several of them, the capacity of slowly setting under water has been fully ascertained by the experiments in which I am now engaged.

1. Limestone from Mr. Wrights, east of Beaver creek, Campbell county. Colour light grey, with dark stripes, micaceous; texture compact, crystalline ; fracture splintery. In the 26 grains this con- sists of, (R. £. K.)

Carbonate of lime, 16.89

Carbonate of magnesia, 6.32

Alumina and oxide of iron, 1.00

Silica, 0.67

Water, 0.12

2. Limestone from Arthur's quarry on Back creek, NW. of Lees- ville, Campbell county. Colour light blue, with grey stripes ; tex- ture rather compact; fracture rather splintery; structure slaty; crystalline.

Carbonate of lime, 28.19

Carbonate of magnesia, 0.61

Alumina and oxide of iron, 0.14

Silica, 0.96

Water, 0.10

8. Limestone from Elk creek. Nelson county, used as flux at the furnace in the vicinity. Colour bluish grey, micaceous; texture rather compact ; crystalline.

Carbonate of lime, 20.87

Carbonate of magnesia, 0.72

Alumina and oxide of iron, 0.38

Silica, 2.88

Water, 0.16

4. Limestone from Captain Perrow's, Beaver creek, Campbell county. Colour pure white; texture compact, crystalline; grain rather fine ; fracture conchoidal.

Carbonate of lime, 18.94

Carbonate of magnesia, 10.18

Alumina and oxide of iron, 0.89

Silica, 0.38

Water, , 0.11

6. Limestone from James river canal between Elk creek and Green way. Nelson county. Colour white ; texture compact ; crys- talline ; fracture conchoidal ; contains disseminated small crystals of quartz.

Oarbonate of lime, 16.08

Carbonate of magnesia 7.58

Alumina and oxide of iron, 0.49

Silica, 0.78

Water, 0.12

6. Limestone from soath side of James river opposite Warmin- ster, Buckingham conntj. Colour pink, mottled with grej ; texture rather compact; snbcrystalline ; grain moderately fine; fracture conchoidal; hydraulic.

Carbonate of lime, 11.17

Carbonate of magnesia, 8.60

Alumina and oxide of iron, 1.04

Silica, 4.12

Water, 0.17

7. Limestone from Pounding Mill creek, near New Market, Nel- son county ; colour light pink ; texture compact ; grain moderately fine ; fracture sharp, scaly.

Carbonate of lime, 12.95

Carbonate of magnesia, 10.80

Alumina and oxide of iron, 0.28

Silica, 0.88

Water, 0.09

9. Limestone from judge Saunders's, Flat creek, Campbell county. Colour blue ; structure slaty. In the 100 grains are contained

Carbonate of lime, 51.3

10. Limestone from James river below Archer's creek, Camp- bell county. Colour grey; subcrystalline with small rhombs of oalc. spar.

Carbonate of lime, 79.5

11. Limestone from one half mile NW. of Dyers mill, Albemarle county. Blue, slaty, alternating with white lamintD.

Carbonate of lime, 77.2

12. Limestone from Arthur's quarry, near Leesville, Campbell county. Bluish grey, micaceous, containing masses of calc. spar.

Carbonate of lime, 80.

13. Limestone from one mile above New Market, Nelson county, quarried for locks on the James river canal. Blue, compact, and traversed by veins of fiesh coloured carb. lime.

Carbonate of lime, 79.5

14. Limestone from James river canal, 2 miles below Warminster, Nelson county. Blue, slaty, micaceous, with calc. spar.

Carbonate of lime, 72.7

15. Limestone from captain Tardy's, near Otter river, Campbell county. Bluish, granular, micaceous.

Carbonate of lime, 69.

16. Limestone from Ko. Irvine's, Buffalo creek, Campbell county. Light grey, slightly micaceous and subcrystalline.

Carbonate of lime, '. 87.8

17. Litbestone from ITancocks quarry, Limestone nm, Albemarle coantj. Blue and slaty.

Carbonate of lime, 60.5

18. Limestone from Rosses furnace, Stonewall creek, Campbell county. Light bluish grey ; granular ; subcrystalline.

Carbonate of lime, 88.4

19. Limestone from near Elk creek. Nelson county, quarried for locks. Dark blue, slaty, and slightly micaceous.

Carbonate of lime, 66.6

20. Limestone from Rivess quarry, near Brookss, Franklin coun- ty. Blue micaceous laminsB, alternating with white subcrystalline carb. lime.

Carbonate of lime, 64.5

21. Limestone from James river canal, between Fishing creek and Opossum creek. White slaty, surface talcose.

Carbonate of lime, 25.

22. Limestone from Buck Island creek, Albemarle county. Col- our dark bine, with white veins of spar ; texture rather compact ; grain moderately tine.

Cai'bonate of lime, 76.4

Chaptbb 3.

Lime$tones of Formation IL

The annexed details relating chiefly to the highly magneaian va- rieties of this formation, while serving to confirm the observations made in previous reports, as regards the hydraulic properties of this class of limestones, will, it is hoped, prove nsefol in pointing out a number of localities of cement rocks not referred to in former pub- lications.

1. Limestone from near tbe Trap Dyke, mUea west of Mount Crawford, Rockingham county. Colour light grey ; texture rather compact; subcrvstalline ; inclining to granular; fractnre rough; hydraulic. In the 25 grains this consists of

Carbonate of lime, 18.50 grains.

Carbonate of magnesia, 10.56

Alumina, tinged with oxide of iron, 0.38

Silica, 0.39 "

Water, 0.17 "

2. Limestone from the eastern base of Prices mountain, Bote- tourt county. Colour light bluish grey ; texture compact ; fracture slightly conchoidal ; grain moderately tine ; highly hydraulic.

Carbonate of lime, 12.96

Carbonate of magnesia, 9.36

Silica, 2.09

Alumina and oxide of iron, 0.87

Water, 0.83

8. Limestone from slaty beds in II., Liberty road, 8 miles north of Big Lick, Roanoke county. Colour dark bluish grey ; moderate- ly compact; slightly subcrystalline; fine grained; containing dis-

seminated Binall specks of iron pyrites, and enclosing geodes of sul- phate of lime ; very hydraolio.

Carbonate of lime, 11.55

Carbonate of magnesia, 8.54

Alamina and oxide of iron, 1 .00

Snlphuret of iron, 0.28

Silica, 8.17

Water, 0.50

4. Limestone from Rich valley opposite the Salt works, Wash- ington county. Colour bluish white ; compact ; fine grained ; hy- draulic.

Carbonate of lime, 12.52

Carbonate of magnesia, 10.38

Alumina, tinged with oxide of iron, 0.18

Silica, 1.86

W ater, 0 .07

5. Limestone from locality miles east of Cedar Grove, Hock- bridge county. Colour bluish grey ; texture compact ; grain mod- erately fine ; fracture slightly conchoidal ; hydraulic.

Carbonate of lime, 12.58

Carbonate of magnesia, 8.97

Alumina and oxide of iron, 0.52

S'llica, 2.82

Water, 0.16

6. Limestone from south side of Shenandoah river, 2 miles from Blackford's furnace. Page county. Colour very light brown and drab; texture compact; grain fine; fracture rather smooth and slightly conchoidal ; hydraulic.

Carbonate of lime, 18.01

Carbonate of magnesia, 10.45

Alumina with trace of oxide of iron, 0.80

Silica, 1.17

Water, 0.07

7. Limestone from locality 4 miles south of New Market. Colour light bluish grey; texture compact; grain moderately fine; weath- ered surface tinged with oxide of iron ; hydraulic.

Carbonate of lime, 18.50

Carbonate of magnesia, 10.63

Alumina and oxide of iron, 0.17

Silica, 0.60

Water, 0.10

8. Limestone from lower stratum at Dr. Blackford's mill race, Page county. Colour light blue, inclining to grey; texture com- pact ; grain moderately fine ; slightly subcrystalline ; some portions of surface filmed with white calc. spar ; very hydraulia

Carbonate of lime, 18.40

Carbonate of magnesia, 9.78

Alumina and oxide of iron, 0.19

Silica, 1.47

Water, 0.16

9. Limestone from locality a little south of Abingdon. Colour blaish grey; texture compact; grain fine; fracture small con* choidal; hydraulic.

Carbonate of lime, 19.55

Carbonate of magnesia, 2.54

Alumina and oxide of iron, 0.28

Silica, 2.51

Water, 0.12

10. Limestone from locality 6 miles NW. of Pattonsburg, on road to Crawfords mountain. Colour dark bluish grey; texture compact; fracture rather earthy, and slightly conchoidal; hy- draulic.

Carbonate of lime, 11.58

Carbonate of magnesia, 9.32

Alumina and trace of oxide of iron, 0.76

Silica,. 8.09

Water, 0.25

11. Limestone from bed passing a little west of Waynesboro', Augusta county. Colour light blue ; texture compact ; grain fine ; fracture slightly conchoidal ; weathered surface, tinged with per- oxide of iron ; very hydraulic.

Carbonate of lime, 12.33

Carbonate of magnesia, 9.58

Alumina and oxide of iron, 0.57

Silica, 2.36

Water, 0.16

12. Limestone from Catawba creek, near Stone Coal gap. Col- our dark bluish grey; texture compact; grain moderately fine; fracture rather uneven ; very hydraulic.

Carbonate of lime, 11.16

Carbonate of magnesia, 9.38

Alumina and oxide of u'on, 0.62

Silica, 8.59

Water, 0.25

1 8. Limestone from gap of Peters mountain, north side of New

river, 4t miles from Grey Sulphur springs. Colour greenish grey ;

texture compact ; grain rather fine ; fracture rather undulating ;

hydraulic.

Carbonate of lime, 11.17

Carbonate of magnesia, 8.31

Alumina and oxide of iron, 1.06

Silica, 4.27

Water, 0.19

14. Limestone from near the mouth of Wolf creek, Giles county.

Colour light grey ; weathered surface, tinged with oxide of iron ;

texture rather friable; crystalline; fractured surface, rough and

seemingly arenaceous ; hydraulic.

Carbonate of lime, 13.23

Carbonate of magnesia, 10.99

Alumina and oxide of iron, 0.14

Silica, 0.55

Water, ; , . 0.09

15. Limestone from locality 8 miles north of Abingdon. Colonr dark bine; texture compact; grain fine; fracture rather smooth and slightly conchoidal ; very hydraulic.

Carbonate of lime, 16.80

Carbonate of magnesia, 7.11

Alumina and oxide of iron, 0.23

Silica, 2.17

Water, 0.19

16. Limestone eight miles north of Fincastle, on road to Dib- brelFs spring. Colour dark bluish grey ; texture compact ; slaty ; grain fine ; fracture slaty conchoidal ; very hydraulic.

Carbonate of lime, 9.20

Carbonate of magnesia, 7.81

Alumina, tinged with oxide of iron, 1.29

Silica, 6.93

Water, 0.18

17. Limestone from west base of Little Fort mountain, opposite Woodstock. Colour light bluish grey ; texture compact ; grain fine ; fracture smooth conchoidal ; very hydraulic.

Carbonate of lime, 12.68

Carbonate of magnesia, 10.12

Alumina and oxide of iron, 0.48

Silica, 1.52

Water, 0.25

18. Limestone from Roaring run, foot of the Two Pointers (mountains), Botetourt. Colour dark bluish grey; texture com- pact; grain moderately fine, subcrystalline; fracture sharp con- choidal ; very hydraulic.

Carbonate of lime, 12.52

Carbonate of magnesia, 7.83

Alumina and oxide of iron, 0.62

Silica, 3.90

Water, 0.13

Chaptkh 4.

Limestones of Formation VI.

1. Limestone from Pattersons creek, near Hampshire furnace. Colour greyish drab; weathered surface tinged with per- oxide of i

iron; texture rather compact; subcrystalline; grain moderately

fine ; structure slaty.

Carbonate of lime, 28.11

Carbonate of magnesia, 0.35

Alumina and oxide of iron, 0.19

Silica, 1.24

Water, 0.13

2. Limestone from Little Ridge, near the Bloomery, Hampshire county. Colour dull bluish grey; texture compact; grain fine; crystalline specks ; fracture rather conchoidal ; hydraulic.

Carbonate of lime, 11.66

Carbonate of magnesia, 7.67

Alumina and oxide of iron, 1.58

Silica, 3.90

Water, 0.19

Chapteb 6.

Limestones of Formation XL

It will be apparent from the following details, that this forma- tion includes beds of limestone of remarkable purity, and adapted to furnish a lime well suited to architectural as well as household and agricultural purposes. Where widely deyeloped, as in Green- brier and Monroe, extensive beds are found in it, containing a con- siderable proportion of carbonate of magnesia, by which, together with the accompanying silica, they are fitted for the manufacture of water cement. Layers of this description are also met with in the northern portion of the state, and within the general limits of the coal region, an example of which is presented below in the specimen from the Cheat river, near the mouth of Laurel run. Numerous other instances of the occurrence of magnesia and hydraulic bands in this formation will no doubt be brought to light by further geo- logical and chemical investigations.

The value of these limestones generally is sufficiently illustrated by the fact, that, excluding the specimen containing a large amount of magnesia, the average proportion of carbonate of lime in those enumerated below is about 86 per cent., indicating a degree of purity equal to that of the better class of dark blue limestones belonging to formation XL, as they are spread out in our great valley.

The last six specimens in the following list having been found devoid of magnesia, ere analyzed no fur&er than to ascertain the percentage of carbonate of lime.

1. Limestone from the neighbourhood of the Bed Sulphur springs, Monroe county. Colour bluish black; texture compact; grain fine; fracture smooth conchoidal.

Carbonate of lime, 22.78

Carbonate of magnesia, a trace.

Alumina and oxide of iron, 0.80

Silica, 1.56

Water, 0.11

Bituminous matter.

2. Limestone from Muddy creek mountain, near Blue Sulphur spring. Colour light grey; texture compact; grain fine; fracture sharp conchoidal. This rock is beautifully oolitic.

Carbonate of lime, 24.55

Carbonate of magnesia, 0.00

AJaminA and osideof iron, O.IS

Silica, 010

Water. 0,06

, This, like all the other light coloared oolitic specimens frooi this formation, ii remarkably pore, containing, an will be seen b; the above resalt, npwanla of SB per cent, of carbonate of Ume.

8. Limestone ftom near Union, Ifonroe coantj-. Colour binish grej; teitare oompaot; suborystalline ; fractnre sharp conohoidal.

Garbonate of lime, 28.98

Carbonate of magnesia, a trace.

Alamina and oxide of iron, 0.14

Silica, 0.47

Water, 0.10

4. Limestone from the inferior portion of formation No. XT.. Cheat liver, three fourths mile below the month of Laarel run. Colour lead grey, with a greenish yellow tinge; teiture compact; grain moderutel; fine; fractnre irregular, eartDj; verj/ hydratilie.

Carbonate of lime, 10.40

Carbonate of magnesia, 6.4B

Alnmina and .oxide of iron, 2.42

Silica, G.OO

Water, 0.31

C. Limestone from superior portion of XI., east side of Lanrel Hill axis, Monongalia count;, used as a flux at the OreenTille fur- nace. Colour spotfl of liglit yellow and grey; texture compact, par- tially aubcryBtalline ; fractare uneven and rather emootb.

Carbonate of lime, 22.0B

Alumina and oxide of iron, 0.68

Silica, 1.81

Water, 0.18

6. Limestone from lower part of XL, need at Jenkins's limekiln. Cheat river, below the month of Qam Camp ran. Colour lead grey; textore compact, slightly subcrystalline; fractare irregalar.

Carbonate of lime, 22.44

Carbonate of magnesia, 0.68

Alumina and oxide of iron, 0.29

fliUca, 1.4B

Water, 0.23

V. Limestone from XL, Cheat river, below Gum Camp mn, Preston oonnty. Colour light grey, with stripes of bloe; textare oompaot; fracture rough plain sorfaee, seemingly arenaceons.

Carbonate of lime, 16.88

Carbanat of magoaaia, O.fiS

Alamina and oxide ot iron, 0.22

Silica, 8.75

Water, 0.14

8. Ljmestoae from XL, Biohard Forman's plantation, Preston oonnty. Ckilonr lead grey; textare oompaot, sabcrystalline; grain flue ; fracture alightly conchoidaL

Carbonate of lime, 22.05

Carbonate of magnesia, 1.48

Alamina and oxide of iron, 0.10

Silica, 0.34

Water, 0.18

0. Limestone from XL, western side of Briery axis, two miles sonth of Kingwood, Preston county. Colour light grey ; texture compact, partially subcrystalline ; grain fine ; fracture irregular.

Carbonate of lime, 22.86

Carbonate of magnesia, 0.70

Alumina and oxide of iron, -0.22

Silica, 1.51

Water, 0.21

10. Limestone from eastern side of Briery mountain, one half mile north of the turnpike. Colour grey ; texture rather compact, slightly subcrystalline ; grain rather coarse.

Carbonate of lime, 16.00

Carbonate of magnesia, 1.69

Alumina and oxide of iron, 0.40

Silica, 6.74

Water, 0.17

11. Limestone from front ridge of Alleghany, opposite the North Fork gap in Knobly mountain. Colour dark bluish grey ; texture compact, subcrystalline ; grdn fine ; fracture conchoidal, smooth.

Carbonate of lime, 22.62

Carbonate of magnesia, 1.00

Alumina and oxide of iron, 0.18

Silica, 1.14

Water, 0.16

12. Limestone from front ridge of Alleghany, opposite Peters- burg; Colour light lead; texture compact; subcrystalline; grain fine ; fracture conchoidal.

Carbonate of lime, 22.18

Carbonate of magnesia, 0.81

Alumina and oxide of iron, 0.88

Silica, 1.60

Water, 0.18

13. Limestone from Everlies mill, near the head of Youghio- gheny, western side of Briery axie Preston county. Colour light grey ; texture compact ; subcrystalline fracture, slightly conchoidal. In the 100 grains,

Carbonate of lime, 92

14. Limestone from the lower part of XI., Deokers creek. Mo- nongdia county. Colour light grey ; compact, subcrystalline ; frac- ture uneven.

Carbonate of lime, 84.5

15. Limestone from the middle of upper limestone of XL, west- ern side of Briery axis, 4 miles south of Kingwood road. Colour light grey ; compact and subcrystalline.

Carbonate of lime, 90.7

16. Limestone from the western side of Backbone axis on Red creek, 6 miles above its month, Randolph county. Colour light grey ; texture compact, &c.

Carbonate of lime, 82.5

17. Limestone from western side of Briery axis, half a mile below the Kingwood, near Roaring creek, on land of Christian Smith. Colour grey, inclining to dun ; texture, &c. as in the above.

Carbonate of lime, 69.5

18. Limestone from upper part of limestone of XL, a short dis- tance west of Mount CarmeL Colour grey ; texture, &c. as before.

Carbonate of lime, 84.5

Chafteb 6.

Limestones of the Coal Measures

In presenting the following results, it gives me great pleasure to be able to announce the fact that by recent trials in my labora- tory many of the bands of limestone included in the coal measures have been proved capable of furnishing a good water cement ; and I would add, that the observations thus far made, lead to the belief that these hydraulic layers are of frequent occurrence, both in the ujper and unoer coal series. In connection with future explora- tions, therefore, particular attention will be directed to the chemi- cal analyses of the calcareous rocks as presented at numerous locali- ties not referred to below, and to the determination of their value as cements or for household and agricultural uses.

In relation to the results here given, it is proper to observe, that they are presented in a somewhat imperfect shape — the process of separating the alumina and oxide of iron not having been completed, and the amount of iron existing in the state of carbonate being now only in progress of examination. These particulars, however, are of little or no economical importance, and would not affect in a sen- sible degree the amount of lime and magnesia here stated. I have therefore thought it advisable to exhibit a few such results, even thongli incomplete, as illustrating the characteristic features of some of the limestones under consideration. Numerous and very detailed analyses of these and other materials, of which partial reports have been from time to time presented, will be given hereafter.

1. Limestone from the vicinity of Morgantown, near Rogerss mill. Dove coloured; weathered surface ferruginous; texture compact; subcrystaHioe ; grain fine; fracture irregular and rather smooth ; eery hydraulic; sets promptly and becomes very hard.

Carbonate of lime, 18.01

Carbonate of magnesia, 4.28

Alnmina and oxide of iron, 2.15

Silica, 4.84

Water, 0.40

2. Limestone from coal rocks near Kingwood, Preston county, Mr. Hagan's. Colour dull bluish grey tinged with yellow ; texture

oompaot; grain fine; fractare conchoidal ; specks of snlphuret of iron and oalc. spar; v&rjf hydraulic; sets promptly and beoomefi very hard.

Carbonate of lime, 14.29

Carbonate of magnesia, 6.95

Alumina and oxide of iron, 2.28

Silica, 2.18

Water, 0.36

8. Limestone from Kanawha valley, beneath Stocktons coal seam, near steam mill. Ooloar doll dark grey ; textaro compact ; grain rather coarse ; fracture conchoidal ; containing carbonaceous matter and specks of iron pyrites ; hydraulic.

Carbonate of lime, 15.70

Carbonate of magnesia, 1.07

Alumina and oxide of iron, 1.60

Silica, 6.01

Water, 0.62

4. Limestone from Hnghess creek, Kanawha. Colour light blu- ish grey ; texture compact ; fractare cdightly conchoidal ; weathered surface earthy and ferruginous.

Carbonate of lime, 14.12

Carbonate of magnesia, 0.62

Alumina and oxide of iron, 1.76

Silica, 8.01

Water, 0.50

6. Limestone from beneath the middle seam of ooal in the King- wood basin. Colour lead blue; texture compact; grain fine; frac- ture irregular.

Carbonate of lime, 19.88

Carbonate of magnesia, 0.70

Alumina and oxide of iron, 0.78

Silica, 8.46

Water, 0.31

6. Limestone from one mile east of Brandon ville, Preston conntyt Mr. Rhodoheaver's. Colour dull dark blue ; texture compact ; grain fine ; fracture rather smooth.

Carbonate of lime, 16.02

Carbonate of magnesia, 2.28

Alumina and oxide of iron, 2.14

Silica, 4.08

Water, 0.82

Carbonate of iron 0.20

7. Limestone from band beneath the lower seam of ooal in the Kingwood basin, colonel Fairfaxes, miles southeast of Kingwood. Colour dark lead grey ; texture compact ; grain fine ; fracture smooth, conchoidal.

Carbonate of lime, 20.85

Carbonate of miesia, 0.88

Alumina and oxide of iron, 0.88

Silica, 2.66

Water, 0.31

8. Limestone from the roagneBian band above the Wheeling coal seam. Colour light grey or drab; texture moderately compact; grain rather Hne ; fracture inclining to be earthy ; hydraulic.

Carbonate of lime, 10.86

Carbonate of magnesia, 6.61

Alumina and oxide of iron, 1.10

Silica, 6.16

Water, 0.27

0. Limestone from the band adjoining the 2 feet seam of coal at Olarkabarg, jodge Duncan's. Colour dull bluish grey, with a light brownish tinge ; texture compact ; grain fine ; fracture rather con- choidaL

Carbonate of lime, 28.88

Carbonate of magnesia, 0.47

Alumina and oxide of iron, 0.24

Silica, 0.28

Water, 0.18

Bituminous matter, a trace.

10. Limestone from the band adjoining the large coal seam, Clarksburg, judge Duncan's. Colour dark bluish grey; texture moderately compact; grain moderately fine; fracture rough and splintery. This rock is under examination aa a hydraulic cement, and from present appearances bids fair to shew striking hydraulio powers.

Carbonate of lime, 16.70

Carbonate of maesia, 2.27

Alumina and oxide of iron, 1.10

SDica, 4.52

WatcTj 0.41

Bitummous matter, a trace.

Chaptbb 7. Iron Ore$ of Formation XL and of the Coal Measurei.

1. Iron ore from formation XI., from the upper seam at the GrenyiUe furnace, Laurel Hill, Monongalia county. Colour reddish brown or olive ; weathered surface light brown or drab ; texture oompaot ; grain fine ; fracture slightly conchoidal.

Carbonate of iron, 28.27

Carbonate of lime, trace.

Carbonate of magnesia, trace.

Silica, 1.12

Alumina, 0.20

Water and bitumen, 0.81

Carbonate of manganese, traoe.

2. Iron ore from XL, average specimen from "Rock vein,"

Grenville furnace. Oolonr blaisfa, inclining to grey ; textnre com- pact ; grain rather fine ; fractare eartbj.

Carbonate of iron, 16.08

Carbonate of lime, trace.

Carbonate of magnesia, trace.

Silica, 6.80

Alumina, 1.04

Water and bitamen, 0.80

Carbonate of manganese, a trace.

8. Iron ore from XI., " Rook vein " at the " Grenville works.*' Contains vegetable remains and nnmerons disseminated scales of mica. Colour grej ; texture rather compact ; grain moderately fine ; fractnre irregular, earthy.

Carbonate of iron, 15.15

Carbonate of lime, a trace.

Carbonate of magnesia, a trace.

Silica, 7.80

Alumina, 0.94

Water, 0.60

Carbonate of manganese, a trace.

4. /rem are ftom XL, Lower vein at Grenville furnace. Col- our dull reddidh brown; texture compact; fracture slightly con- choidal, disclosing minute scales of mica.

Carbonate of iron, 17.79

Carbonate of lime and magnesia, 0.85

Silica, 6.62

Alumina, 0.74

Water, 0.41

Carbonate of manganese, a trace.

6. Iron ore from XL, upper vein, Henry Clay furnace, Monon- galia county. Colour grey with a reddish brown tint ; texture com- pact ; grain fine ; fracture conchoidai ; weathered surface ochreous.

Carbonate of iron, 22.28 '

Carbonates of lime and magnesia, 0.20

Silica, 1.87

Alumina, 0.85

Water, 0.22

Carbonate of manganese, a trace.

6. Iron ore from XL, German Settlement. Colour bluish grey inclining to brown ; textnre compact ; grain fine ; fractnre irregular conchoidai. Contains films of carbonate of lime and minute specks of Bulphuret of iron, sparsely disseminated.

Carbonate of iron, 28.00

Carbonates of lime and magnesia, 0.80

Silica, 1.02

Alumina, 0.80

Water, 0.28

Carbonate of manganese, a trace.

7. Iron ore from Hollow ran, a brancli of Muddy creek in Pres- ton conntj. Color dark blae ; texture compact ; grain fine ; fracture alightlj conchoidal ; weathered surface yellowiah brown.

Carbonate of iron, 20.64

Carbonate of lime, 0.56

Carbonate of magnesia, 0.94

Silica, 2.11

Alumina, 0.53

Water, 0.26

Carbonate of manganese,

8. Iron ore from Stoney run four miles above the turnpike, Hardy county. Colour light gray; weathered surface tinged with per-oxide of iron; texture compact; grain fine; fracture conchoidaL

Carbonate of iron, 19.89

Carbonate of lime, 0.84

Carbonate of magnesia, 0.64

Silica, 2.54

Alumina, 0.46

Water, 0.35

Carbonate of manganese, a trace.

9. Iron ore from falls of Stoney river, Hardy coanty. Colour dull lead grey, inclining to brown ; texture compact ; grain rather fine ; fracture splintery.

Carbonate of iron, 17.75

Carbonate of lime, 1.44

Carbonate of magnesia, 1.00

Silica, 8.05

Alumina, 0.90

Water, 0.45

Carbonate of manganese, a trace.

10. Iron ore from shales above the calcareous band separating the two seams of coal )it col. Fairfax's, Preston county. Colour blue in interfor ; exterior composed of concentric layers per-oxidated by exposure to the atmosphere ; texture compact ; grain fine ; frac- ture slightly conchoidal.

Carbonate of iron, 17.16

Carbonate of lime, 1.46

Carbonate of magnesia, 3.01

Silica, 2.62

Alumina, 0.45

Water, 0.58

Carbonate of manganese, a trace.

11. Iron ore from shales above the lowest seam of coal on North branch of Potomac, six miles below the mouth of Abraham's creek. Colour dark bluish grey with a brovmish tint ; weathered surface dark brown ; texture compact ; grain fine ; fracture conchoidaL

Carbonate of iron, 19.30

Carbonate of lime, 0.81

Carbonate of magnesia, 0.70

SUica, 2.85

Alumina, 0.61

Carbonate of manganese, a trace.

Water, 0.83

12. Iron ore from coal measures, M. Hartmans, Crab Orchard, Preston county. Colour deep red inclining to brown ; texture com- pact; grain fine; fracture sligbtlj conchoidal; powder dark red; contains vegetable impressions.

Peroxide of iron, 16.67

Lime, 0.15

Magnesia, 0.19

Silica, 6.24

Alumina, 0.97

Carbonate of manganese, a trace.

Water, 0.66

13. Iron ore from Wilson's mill, shales between the first and second seam of . Colour bluish grey inclining to brown; texture compact; grain apparently coarse; fracture slightly conchoidal.

Carbonate of iron, 15.41

Carbonate of lime, 0.87

Carbonate of magnesia, 0.56

Silica, 6.22

Alumina, 1.15

Carbonate of manganese, a trace.

Water, 0.51

14. Iron ore from coal measures, Valley famace, Monongalia county. Colour reddish brown, inclining to grey ; weathered sur- face ochreous ; texture rather compact ; grain seemingly coarse, but not so to the touch ; fracture irregular ; contains vegetable impres- sions.

Carbonate of iron, 19.18

Carbonate of lime, 0.93

Carbonate of magnesia, 0.70

SUica, 8.18

Alumina, 0.51

Water, 0.44

Carbonate of manganese, a trace.

15. Iron ore from the Valley furnace as above, called by the miners kidney ore. Colour bluish grey, inclining to brown ; weath- ered surface ochreous ; texture compact ; grain nne ; fracture plane.

Carbonate of iron, 19.55

Carbonate of lime, 1.10

Carbonate of magnesia, 0.75

Silica, 2.80

Alumina, 0.35

Water, 0.50

Carbonate of manganese, a trace.

16. Iron ore from shales above the second seam at Brantzbnrg, Kortb branch of Potomac. Coloar greyish blue ; texture compact ; grain moderately fine ; fracture irregular ; weathered surface tinged with peroxide of iron.

Carbonate of iron, 17.17

Carbonate of magnesia, 0.78

Carbonate of lime, 0.45

Silica, 6.18

Alumina, 0.69

Carbonate of manganese, a trace.

Water, 0.39

It will be remarked of the above analyses, that a trace of carbon- ate of manganese is stated as generally present, both in the ores of XI. and of the coal measures. In only two or three instances was its amount sufficient to be estimated, and in these cases it was found so inconsiderable as to be undeserving of note. With regard to several other specimens yet to be analysed, there are indications of a larger proportion of this ingredient. I would add that a pre- cise determination of its amount will always be given where it is capable of being noted, or worthy of mention in an economical point of view.

Coals Of Tiie Great Western Coal Region.

Fbom Fobmation Xi.

Though not properly included in the coal measures, the coals of this formation being found either along the margin of the great basin or in the axes within its boundaries, are in general so contiguous to the seams of the lower coal series, that thej may with propriety be treated of in the same connection.

1. Coal from Little Sewell, near the top, a short distance below formation XII. Composed of alternating shining and dull black lamincB. In the 100 grains, contains,

Carbon, 80.24

Volatile matter, 17-48

Ash, 2.28

2. Coal from same locality ; aspect the same as the foregoing.

Carbon, 77.64

Volatile matter, 17.86

Ash, 5.00

Fbom Bio Sewell Mountain.

8. Coal from the east side of Big Sewell. Rogers's seam. Com- posed chiefly of shining jet black lamina), with occasional thinner ones of dull black.

Carbon, 76.88

Volatile matter, 22.82

Ash, 1.80

4. Goal from west flank of Big Sewell. Tyrees bed. Composed of dull black laminse.

Carbon, 67.84

Volatile matter, 30.08

Ash, 2.08

5. Coal from west side of Big Sewell. Deems. Composed of jet black shining laininsB ; fractare prismatic.

Carbon, 71.78

Volatile matter, 27.13

Ash, 1.14

Fbom Tra.Ot Betwesn Bio Sewell A.Nd Kanawha.

6. Coal from Mill creek, Fayette county. Paris & Woods bank. Composed of shining black lamines, with films of charcoal.

Carbon, 71.88

Volatile matter, 26.20

Ash, 1.92

7. Coal from Scrabble creek. Shining and compact.

Carbon, 63.36

Volatile matter, 29.04

Ash, 7.60

8. Coal from Bell creek. Doll and friable.

Carbon,

Volatile matter, 82.16

Ash,

Lower Coal Sebie8.

Fbom The Yallet Of The Kanawha.

9. Coal from SW. side of Keller's (Kelley's, Ed.) creek. Lifweit $eam, Hansford's. Brilliant and compact.

Carbon, 60.93

Volatile matter, 87.08

Ash 2.00

10. Coal from Stockton's mine, near mill. Second seam. Deep blaok ; shining and compact.

Carbon, 74.66

Volatile matter, 21.13

Ash, 4.32

11. Coal from L. Raffher's. Campbell creek, or second seam.

Carbon, 55.76

Volatile matter, 82.44

Ash, 11.80

12. Coal from Noyes, Rand & Co.'s. Campbell's creek, or <md seam.

Carbon, 64.16

Volatile matter, 82.24

Ash, 8.60

18. Coal from Noyes, Rand & Co.'s. OampbelFs creek, or sec- end 96am,

CarboD, 65.64

Volatile matter, 81.28

Ash, 8.08

14. Coal from Cox dc Hannah's (Hanna, £d.) Third team. Deep black, shining and compact

Carbon, 51.41

Volatile matter, 42.55

Ash, 6.04

15. Coal from Fanre's bank. Upper eeam, beneath the black flint.

Carbon, 58.20

Volatile matter, 85.04

Ash, 1 1.76

16. Coal from upper $eam, Daniel Ruffner's.

Carbon 49.84

Volatile matter, 44.28

Ash, 5.88

17. Coal from Bream's bank. Third uam.

Carbon, 57.76

Volatile matter, 83.68

Ash, 8.56

18. Coal from Smithers' bank.

Carbon, 64.52

Volatile matter, 29.76

Ash, 15.76

19. Coal from Hughes's bank. Brilliant and compact.

Carbon, 62.32

Volatile matter, 32.88

Ash, 4.80

20. Coal from Danl. Rnffher's. Upper seam.

Carbon, 67.28

Volatile matter, 85.08

Ash, 7.64

21. Coal from Warth h English's.

Carbon, 64.00

Volatile matter, 89.76

Ash, 6.24

FBOM THE HAlCPSniBE AND HARDT BASINS.

22. Coal from lower eeam Brantzbarg, north branch of Potomac, 2 miles above the mouth of Savage.

Carbon, 72.40

Volatile matter, 19.72

Ash, 7.88

28. Coal from Oliver's tract--12 foot seam.

Carbon, 79.08

Volatile matter, 16.28

Aflh, 4.64

24. Goal from Sigler*8 mine, near Westernport, Maryland — 12 foot seam.

Carbon, 82.60

Volatile matter, 15.76

Ash, 2.64

25. Goal from Lonaconing, Marjrland — 12 foot seam.

Carbon, 77.48

Volatile matter, 19.87

Ash, 3.20

26. Coal from Macdonald's, Abraham's creek. Third Meant,

Carbon, 74.00

Volatile matter, 18.60

Ash, 7.40

27. Coal from near the turnpike, 1 mile from top of Alleghanj.

Carbon, 77.12

Volatile matter, 19.60

Ash, 8.28

28. Coal from Vandovers, near N W. turnpike.

Carbon, 61.44

Volatile matter, 14.28

Ash, 24.28

29. Coal from Kitzmiller's, Hardy county.

Carbon, 79.76

Volatile matter, 16.48

Ash, 4.76

80. Coal from falls of Stoney river, Hardy county. Lower seam.

Carbon, 79.16

Volatile matter, 15.52

Ash, 5.32

81. Coal from Michaers, near Abraham's creek, 6 miles above the turnpike.

Carbon 72.40

Volatile matter, 15.20

Ash, 12.40

82. Coal from Stoney river, 1 mile north of turnpike.

Carbon, 88.86

Volatile matter, 13.28

Ash, 8.86

88. Coal from MichaePs, upper part of seam.

Carbon, 46.24

Volatile matter, 14.96

Ash, 89.80

Loweb Coal Series. From Pbe8Ton And Monongalia Basins.

84. Goal from colonel Fairfax's, Eingwood basin. Upper- team.

Carbon, 58.77

Volatile matter, 81.75

Ash, 14.48

85. Coal from do. do. Middle seam, 2i milos from Kingwood.

Carbon, 65.82

Volatile matter, 27.77

Ash, 6.91

86. Coal from Ro. Forman's basin southeast of Eingwood basin.

Carbon, 73,68

Volatile matter, 21.00

Ash, 5.32.

87. Coal from J. Martin's, branch of Deep Hollow creek, Pres- ton county.

Carbon, 65.42

Volatile matter, 28.42

Ash, 11.16

88. Coal from Mr. Beatty's, 8 miles from montli of Buffalo Lick run.

Carbon, 62.66

Volatile matter, 29.60

Ash, 7.84

89. Coal from Formans mill. Big Sandy, 1 mile from Brandon- ▼ille, Preston county. Middle uam.

Carbon, 67.60

Volatile matter, 22.40

Ash, 10.00

40. Coal from Morton's, If mile NW. of Brandon ville. Upper eeam.

Carbon, 65.28

Volatile matter, 30.80

Ash 8.92

41. Coal from Mr. Price's, Cheat river, near King wood.

Carbon, 60.36

Volatile matter, 25.00

Ash, 14.64

42. Coal from Mr. Seaport's, Big Sandy basin, west side of Big Sandy river.

Carbon, 66.64

Volatile matter, 27.12

Ash, 6.24

43. Coal from Mr. Ilagan's, King wood basin, 1 mile west of Eingwood.

Carbon, 68.32

Volatile matter, 26.48

Ash, 5.20

44. Coal from same locality as above.

Carbon, 67.28

Volatile matter, 29.68

Ash, 8.04

45. Coal from Mr. Wall's, Big Sandy bafiin, west side of Cheat.

Carbon, 60.04

Volatile matter, 26.88

Ash, 13.08

46. Coal from Mr. Cresap's, i mile SW. of Kingwood.

Carbon, 64.24

Volatile matter, 80.24

Ash, 5.32

Upper Coal Series.

47. Coal from main seam at Clarksbarg. Upper coal seriet.

Carbon, 56.74

Volatile matter, 41.66

Ash, 1.60

48. Coal from same seam. Cannel coal found near the middle of the seam.

Carbon, 49.21

Volatile matter, 45.43

Ash, 5.86

49. Coal from main $eam Prantytown. The same with the Clarksburg seam.

Carbon, 57,60

Volatile matter, 89.00

Ash, 3.40

50. Coal from main seam Morgantown. The same as the pre- ceding.

Carbon, 60.54

Volatile matter, 87.30

Ash, 2.14

Report

Of The Progress Of

The Geological Survey

Of

The State Of Virginia

FOS TUB YEAR ISIfi.

Offxob or TBI Board of Public Wobks,

February 3d, 1841.

Sib, I herewith transmit the annual report of the geologist of the state for the past year, which you will please lay before the house of delegates.

This report relates chiefly to the marl region between the Poto- mac and Rappahannock rivers, the northern district east of the Blue Ridge, and the great western coal region.

Thomas W. Gilmer.

To the Speaker of the House 0/ Delegates,

Report.

In compliance with the law requiring me annually to present an account of the progress of the geological survey of the state, I beg leave to make the following report :

Chapter I.

Opebations Aad Present Condition Of The Survey.

Section I.

Organization of the Corps, and Plan of Operations during the Past

Season,

Ab the hoard is aware, the resignation of Professor James B, Sogers and Charles B. Hayden, who had heen able and efficient members of the geological corps, from an early period of the survey, occasioned some delay in carrying into execution the entire plan of operations projected for the season. As soon, however, as the time for field duties arrived, the remaining members of the corps, Br, Baydy Mr, Briggs and Mr, Slade, repaired to the districts assigned them, and the vacancies above referred to having at length been supplied, by the appointment of Mr. Samuel Letois and Mr. Thomas S, Ridgtoay these gentlemen, also, as soon as practicable, entered upon their allotted duties.

In continuation of the explorations in which they had been en- gaged during the preceding season, Mewrs. Boyd Briggs and Slade were directed to pursue their enquiries in the unexplored portions of the great geological sub-divisions of the state in which they had previously been occupied, and in which their labours could be most beneficially employed.

Accordingly, Dr. Boyd entered upon a detailed examination of that sub-division of the district lying between the Blue liidge and the western boundary of the marl region, which extends from the James river and a line passing through Albemarle county to the

4U

Potomac ; embraciDg a wide extent of primary and metamorphio rocks, an important portion of the formation designated in mj last yearns report as the middle secondary, and the narrow, thongh im- portant belt of still more recent sedimentary rocks, lying adjacent to the western limits of the marl, for most of the distance between the James river and the Potomac.

Guided by the knowledge of the more marked geological fea- tures of this region, already acquired by observations of my own, during a previous season, i>r. Boyd proceeded, at once, to trace the various important belts of rook occupying this extensive area, with the view of defining them accurately on the map, noting carefully the numerous detached beds of limestone occnmng in a prolonged zone towards its western boundary, the ores of iron and other use- ful minerals, met with at various points, and connecting with all these local observations and longitudinal tracings, a series of accu- rate sections extending entirely across the region, in nearly equidis- tant parallels from its eastern margin to the summit of the Blue Bidge.

With the view of completing the exploration of that portion of the corresponding district south of the James river, to which the minute researches of preceding seasons had not been extended, Mr, Samuel Lewis was directed to pursue a course of examinations sim- ilar to those of Dr, Boyd in the district lying between the James river and the Carolina border, and between the western boundary of the marl and the margin of the district previonsly explored. Be- sides making numerous lines of section, ana intervening observations relating to the primary rocks occupying by far the larger portion of this area, he was instructed to complete the tracings formerly be- gun, of the coal basins lying in Chesterfield Powhatan Benrico and Goochland counties, so as to determine, with as much accuracy as our means of research permit, the irregular margin of primary by which they are enclosed, and to ascertain whether similar coal- bearing strata recur at other places in the district nnder his charge.

To Mr, Briggs was committed the task of continuing the explo- rations begun by him during the preceding season, in the great west- em coal region of the state, by prolonging his observations on the Ohio, as far as the Kentuehy line, at the mouth of Big Sandy, by carrying several important sections entirely or partially across the northwest portion of this region, among which was a preliminary line of observations along the Little Kanawha, and by a minute ex- ploration of the valley of the Monongahela, comprehending the wide tract between the western flank of Laurel Hill, and the line along which the upper coal measures, and the important accompa- nying rocks, disappear beneath the level of the streams.

In connection with these extensive and minute enquiries, chiefly conducted in the northwestern portion of the state, a series of meas- urements and other observations, were directed to be made by Mr. Bidgway from the falls of the Great Kanawha to Point Pleasant, with the view of completing the data for an accurate section along this line, and to this gentleman the further duty was assigned, of

making preliminary explorations on the Goal, Gnyandotte and Sand J rivers, so as to embrace the general features of that portion of the great western ooal region, l)riDg between the Kanawha river and the Kentucky line.

To Mr. Slade was assigned the duty of continoing the revision of certain portions of the Appalachian belts, in the district included between the western slope of the Blue Bidge, and the eastern bound- dary of the great coal basin of the west; imparting greater accuracy to sections previously formed, constructing others illustrative of new lines of observation, and marking out the boundaries of some of the Appalachian groups of strata with more minuteness than had been previously attained, associating with the general tracing of the formations investigated, an examination of all the important lo- calities of ores or other minerals included in them, and not previ- ously made the subject of special enquiry.

In prosecuting the plan of operations contemplated in the above allotment of duties, to the several members of the corps, the amount of labour performed, and the progress made towards the completion of the survey, though entirely satisfactory, has fallen short in some portions of the field, of the anticipations expressed in my last yearns report. This result, in part occasioned by the unavoidable delay in filling the vacancies which occurred in the corps early in the sea* son, and by the time required by the newly appointed assistants to become familiar with the duties specially entrusted to them, was in a still greater degree the consequence of the protracted iodi:jposition of Dr, Boyd which, after causing frequent temporary suspensions of his labours, compelled him to withdraw entirely from active du- ties early in September, and in a few days after his arrival at the University, terminated in his much regretted death.

The board have long been aware of the zeal, knowledge and fidelity with which this gentleman uniformly executed his share of the labours of the survey, as well in aotive exploration, as in the selection and arrangement of specimens towards the formation of the public cabinet ; nor do they need to be informed of the great value of his skill as a mineralogist, as well as a geological observer in the detailed examinatiim of the widely extended primary region, in which for the last three years, he has been almost exclusively employed. Of his amiability of heart, and his general merits as a cultivator of those branches of science to which he was devoted, it would be inappropriate here to speak. It will sufiSoe, while advert- ing to these and other engaging traits of his character, briefly to record an expression of our deep regret for the loss of his compan- ionship and services in the corps, and of our sincere respect tor his memory as a gentleman and a lover of natural science.

Since the close of our operations in the field, the chemical and graphical departments of the survey have as usual occupied a por- tion of the attention of myself and assistants, and will continue to receive a juat share of our time and labours until the period for as- anming field duties shall arrive.

The task enjoined upon each of my assistants, of drawing up de-

tailed reports of their observation daring the season of active Ia* boar, in general, giving them full employment until the winter is far advanced, and mj own report calling for much additional labour in consequence of the imperfect shape of mateiials from which, at this period, I am compelled to frame it, the chemical and other collat- eral departments of our labours cannot be brought into full activity until a later period, and as a consequence of tliis, only a small por- tion of the details relating to these departments, and having im- mediate reference to the subjects treated of in the annual report, are in a state of sufficient forwardness for publication.

Before drawing to a close this general sketch of our operations, completed and in progress, it is proper to add, that continuing the employment of the thermometer as a means of determining heights, we have during the past season been enabled to make numerous useful measurements in various parts of the Blue Ridge, some of the parallel mountains lying west of it in the Appalachian belt, as well as of the lofty hills bordering on the Kanawha and Ohio rivers. These, and the measurements made in the two preceding year are already sufficiently numerous to contribute important aid towards determining, with comparative accuracy, a highly interesting feature in the topography of tlie more rugged portions of the state, and at the same time to facilitate some of the most difficult explorations we are called upon to make.

By greatly multiplying the observations of this nature, as it is my wish to do, during the coming season, a most important acces- sion will be made to our knowledge of the physical configuration of our territory, and while in this way the means will be furnished of representing accurately the results of our labours in sections and on the map, data will be afforded of no small value to future engineer- ing enterprises in various quarters of the state, and of much general interest, as elucidating an important element in its geography.

Reserving these and other topographical details for my final re- port, I may be allowed to niention, in illustration of the general interest of the class of observations now in view, that by their means we have recently confirmed the conjectural opinion, prevail- ing throughout the southwestern quarter of the state, as to the alti- tude of the lofty peaks which form the prolongation of the great chain lying between North Carolina and Tennestee,

The elevation of the Balsam and White Top mountains, situated in the southwest angle of Grayson county, above the level of the South fork of Holston, near the state line, has been found of such amount as, when increased by the known elevation of the level thus referred to, to place the summits of these peaks at an altitude of up- wards of 6000 feet above the level of the sea. This elevation, ex- ceeding by about 1000 feet, the height usually but I think errone- ously assigned to the Peak of Otter, is, I believe, the greatest alti- tude yet satisfactorily ascertained in Virginia or indeed in any of the middle and southern states, and may be considered as defining approximately, if not absolutely, the culminating point of the nu- merous chains of mountains by which they are traversed.

Sbotion II.

Completion of (he Survey,

Notwithstanding the delay and partial saspeneion of onr opera- tions in some parts of the state daring the past season, I am happy still to have it in my power to say, that I look with confidence to the completion of our explorations and revisionary lahoars in the field, by the termination of the next campaign.

The districts remaining to be explored, are already well under- stood as to their marked geological features, and will present no im- pediments to enquiry for which we are not fully prepared, or which are likely to retard the rapid progress of our work. In order to com- plete our knowledge of all that portion of the state lying to the east of the Blue Ridge, it will be necessary to make additional researches in the primary region north of the James river, together with some farther observations in the western portion of the Tertiary marl re- gion, between the Pamunkey and Eappahannock rivers, as well as a general exploration of Aceomnch and Northamptcn counties. With regard to the western division of the state, I have little reason to doubt that, by continuing our revisionary work and measurements in the mountainous belts of the Appalachian formations, and includ- ing the examination of that portion of Randolph county which has not yet been examined, and by employing an adequate force in those parts of the great western coal region where our explorations are either incomplete, or have not yet been commenced, we shall, by the termination of the season, have attained such a knowledge of every part of this vast territory, as will enable me to give accurate descriptions and delineations of its geology, and to present a com- plete and finished picture of its numerous and valuable mineral re- sources.

There will then only remain to be executed such further duties oonnerted with the preparation of the sections and maps to accom- pany the final report, and with the analysis and arrangement of specimens for the cabinet, as may be found necessary for the com- pletion of these departments of the survey. In the meantime, the final report for which I am already preparing, and with which I propose to occupy myself during the progress as well as after the close of these auxiliary labours, will be advanced with all the rapid- ity compatible with the magnitude of the task of framing such a work in a manner suitable to the importance and dignity of the en- terprise of which it is to detail the results, and to constitute the crowning labour.

In thus adverting to the approaching termination of my arduous tasks, I may be allowed to express the heartfelt satisfaction with which I contemplate this wished-for result, and the real pleasure I experience in the anticipation of bringing the enterprise to a close at as early a period, and with as small an expense to the state, as in my early calculations I pronounced adequate for the purpose.

In proof of the punctuality and economy here referred to, I may be permitted to remind the board, that when in the report of 1886,

I urged the expediency of augmenting the annual appropriation from five to eight thousand dollars, I expressed the conviction, that vith the force at that time at command it would not he practicable to bring the survey to a termination in less than twelve years; while with the enlarged means then solicited, the work might be completed in one half the time, and at an expense which would probably fall short of fifty thousand dollars.

As yet, less than five years have elapsed since the organization of the corps under the enlarged appropriation, and the expenditure, including that for the first year of the regular survey, has scarcely amount to 86,000 dollars.

Section III.

Subjects and Plan of the Present Rep&rt,

In conformity with the plan adopted in the report of last year, I purpose, on the present occasion, confining myself to a sketch of such districts of the state as have been most completely explored, and as from their simple geological features, admit most readily of being illustrated without the aid of sections or other drawings, add- ing subsequently a brief account of our operations in other regions still under investigation, and closing as usual with a variety of chem- ical details.

In fulfilling this design, I deem it unnecessary, and indeed inex- pedient, to aim at fullness of detail, even to the extent attempted in my last year's report, as from the advanced stage of onr labours, the final report, comprehending all the results, with the requisite ac- companiment of numerous graphical illustrations, will soon be in progress of preparation for the public eye. Indeed were it not that an annual sketch of the progress of the aurvey is required by the enactment providing for its execution, I would feel myself author- ized to dipense with any further partial reports of this nature, and would prefer devoting the time and labour they demand, to the advancement of the researches remaining to be performed, and the preparation of materials for the final report.

In view of these considerations, the board will, I have no doubt, unite with me in admitting the propriety of restricting my present report within comparatively narrow limits.

I shall accordingly, therefore, proceed to give a brief sketch of the geology of the following districts :

1. That portion of the marl region situated between the Poto- mac and Rappahannock rivers.

2. The narrow belt occupied by the upper secondary sandstones and the marls extending along the eastern margin of the primary rocks from Petersburg to the Potomac.

8. Parts of the northern primary district lying between the Blue Ridge and the belt Inst mentioned, and between the range of AlbemarSsy Fluvanna and Oooehland counties and the Potomac, in-

dnding an important portion of the intemipted belt of the middle secondary formation.

4. Portions of the great western coal field, including particularly a part of the Monongahela valley and the valley of the Ohio.

In addition to these subjects of more specific illustration, I shall briefly describe the course of our explorations in the eastern por> tion of the primary district lying south of the James river, and in the wide region of our western coal field.

As the various labours executed in the Appalachian region dur- ing the past season, bear immediate reference to sections, measure- ments, and minute tracings on the map, and from the complexity of structure and topography to which they relate, would not admit of being satisfactorily described without the aid of numerous drawings, I deem it expedient to omit any prolonged description of them at present, and shall, as regards this region, confine myself to the re- port of some chemical details of interest, relating to its rocks and ores.

CHAPTER n.

TEBTIABT MARL REGIOy BETWEEN THE POTOMAC A2fD RAPPA-

Haxxock Rivers.

SEOnON I. I

Extent and Topographical Features.

The portion of the state referred to under this head, embraces the counties of Laneatter Northumberland Richmond, Westmore" land and King George together with the eastern part of Stafford county; thus including the district usually denominated the Northern Neck, and extending some distance beyond it to the west.

This area forms the northern portion of the tertiary region of '

Virginia presenting exteufdve deposits of each of the two subor- dinate divisions of the tertiary formation, described in former re- ports, as occupying the tide water districts of the state. The more recent of these subordinate formations, the Meiocene, or middle Tertiary, extends from near the bay shore, westward, over the larger portion of the peninsula; while the older, or Eocene deposit, with an occasional capping of the former, occupies the remaining area on the west,

The precise boundaries of these formations will be hereafter de* scribed.

Topographical Features, — The general aspect of the penin- sula, and more especially of the four eastern counties, is that of a nearly level plain, maintaining an average elevation of from sixty to seventy feet above the tide. This plain, gently furrowed by numerous ravines, subordinate to the creeks and inlets indenting the peninsula, frequently subsides to a lower level, in approaching the rivers on either side. The wide bench thus formed, sometimes

extends in a direction parallel to the river for a distance of seTeral miles, presenting an unvarying nniformitj of elevation, and reach- ing nearly to the water's edge. A third, and lower plain, frequent- ly intervenes between the river bank and the table land above de- scribed, but in many cases, this terraced configuration of the sur- face is not observed, and the high nod precipitous clififs which rise very near tlie waters edge, retain the general level of the inland portion of the peninsula. Although the usual elevation of this dis- trict is such as above described, at several points a far higher level is attained. The ridge which forms the water-shed of the streams flowing into the Potomac and Rappahannock, approaching very near to the former, constitutes, in some places, the river bank. At these points it attains an unusual elevation, towering, as at Strat- ford and Chantilly to a height of about one hundred feet above the water's edge, and affording, from its summit, an extensive and en- chanting view of the noble river which laves its base, of the culti- vated farms around, and of the cliffs on the opposite or Maryland side of the Potomac. At ''Sprise Bill, about four and a half miles from Smith's Point, the ridge bends round to the south, and contin- ues for some distance in a direction across the peninsula, preserving an elevation of about sixty feet. Its declivity on the east forms an abrapt termination of the higher level of the neck, between ivhich and the bay is an extensive flat, of from two to four miles in width, rarely rising beyond the height of ten feet above the level of the tide, and in some places so low, as to be occasionally over- flowed.

The western portion of the peninsula, though still in the main presenting a similar uniformity of surface, is somewhat more ab- ruptly furrowed. This inequality increasing as we procee<l further to the west, becomes quite conspicious at the Paspitansy hills, in King Oeorge and in the neighbouring parts of Stafford county, ad- jacent to the line of secondary sandstone, which forms the western limit of the Tertiary formation. The material forming the super- ficial strata in the lower portion of the peninsula, is usually a mix- ture of sand and clay, in a state of minul subdivision, and more or less tinged with the oxide of iron. Sometimes this is intermixed with small gravel, of a ferruginous appearance, bnt it rarely con- tains pebbles or bowlders of any notable dimensions. The diluvial matter assumes a coarser texture, as we proceed westward, pre- senting, when denuding forces have not removed the superficial beds, alternate strata of sand and pebbles, the latter varying from a half inch to several inches in diameter. In many places, these bowlders, derived in great part from the neigh bonring beds of sand- stone, are strewed profusely over the surface, and, together with the superficial layers of white and siliceous sand, render the soils of the higher portions of this district comparatively unproductive, whi'e upon the lower levels, contiguous to tho large rivers, or their tributarias the beds of marl and their associated sands and clays, mingling their fertilizing materials with the soil, have contributed to impart to it a far higher agricultural value.

Section II.

Of the LimiU of the Meiocene and Eocene Districts of the Penin'

sula {of Northern Keck, Ed.).

Bounded on the west by the secondary sandstone before re- ferred to, the Eocene formation extends eastward for some dis- tance down the neck, until at length, with a very gentle eastern dip, it disappears below the level of the tide. The most eastern points in which it continues visible, are here regarded as forming the boandary of the formation towards the east, and the district in- cluded between a line traced tbrongh these points, and its bound- ary to the west is, for convenience sake, designated as the Eocene district, although at some places within its confines, as in other parts of the marl region, beds of Meiocene occur overlying the Eocene.

In tracing the boundary of the Eocene and Meiocene marls, as exposed in the neck, several localities, marking the eastern termina- tion of the former deposit, were carefully inspected in the antici- pation of discovering beds of Meiocene shells above them, or imme- diately beyond them to the east. It was found, however, that strata of clay, lying acacent to the Eocene on this side, occupied an inter- val in which fossils of neither of these formations could be dis- tinctly found ; and that still further on, the beds of the Meiocene came in view. This intervening tract, as seen upon Potomac and Rappahannock, is flat and low. Without, then, pretending to an exact delineation of the boundary in question, which, from the na- ture of the case, would be impracticable, it will be sufficient to con- sider it as coincident with a right line, connecting the mouth of Chingoteague creek on the Rappahannock, with Mathiass Point upon the Potomac.

A brief account of the character and situation of the strata, as observed at these two points, will serve to illustrate the propriety of fixing upon them as its termination.

To tlie west of the mouth of Chingoteague creek, for a distance of more than half a mile, the north bank of the Rappahannock has an average height of about fifteen feet above the river. At its up- per end, the banks consist of a stratum of the green sand marl, ex- tending to the height of twelve feet above the water line, upon which reposes a layer of diluvial sand and clay, about three feet in thickness. In approaching the creek, the level of the marl stratum is observed steadily to decline, while the thickness of the incumbent bed augments, until at a point within two hundred yards of the mouth of the creek, the former entirely disappears below the level of the river. At this point, the diluvial capping is about fourteen feet in thickness, consisting of a layer of sand and pebbles about seven feet thick, resting upon a stratum of whitish clay, which reaches to the water line.

The Eocene character of these subjacent beds is unequivocally marked. At the base of the bank a dark greenish layer presents

itself, rising to the beigbt of five or six feet, containing nnmerona impressions of the Eocene Carditas, and other shells, of a brownish colour. Over this is a layer of a lighter hae, containing bands of white calcareous matter, obviously the remains of shells.

To the east of Chingoteague creek, the bank preserves its former height for about three fourths of a mile; after this it becomes much depressed, and continues to be low for some distance down the river. Here no trace of fossils of either the Eocene or Meiocene period could be discovered, the bank consisting exclusively of dilu- vial sand and gravel. But still further down the river, beds of the latter are observed, and these continue, at intervals, to near the ex- tremity of the peninsula.

An equally marked termination of the Eocene is presented in the neighbourhood of Mathiaas Point, on the Potomac. At Wood- Btoehf about one third of a mile above the point, the cliffs rise to the height of from forty to fifty feet, exhibiting an exposure of the Eocene strata reaching to a di.tance of nearly twenty-five feet above the surface of the river. The lower bed, about eight or nine feet thick, is rich in the fossils characteristic of the Eocene; but the layer, incumbent on this, though filled with ferruginous impressions of shells, retains none of the shells in an unchanged condition. The bed of reddish clay which forms the upper portion of the bank, is separated from the strata just described, by a thin band of ferra- ginons gravel and sandstone, such as is frequently seen occupying a similar position on the Pamunkey, and in other localities.

Above this place, on the adjacent estate called "Borodino," (the residence of Mr, ParJre) the banks, after sinking to a level with the flats, again rise with some abruptness, to an elevation of from forty to sixty feet. The lower stratum of the marl, contain- ing shells in considerable number, is here but little raised above the level of the water. A layer deeply tinged with green sand, and blotched with oxide of iron, rests on this to the height of from four to five feet. Another, but not fossiliferons bed, belonging to the same series, reposes upon the latter, but the piles of fallen earth, at present, preclude an accurate examination of its nature and extent. Still further westward, at " Albion,' the estate of Mr, Miuon, the fossiliferons Eocene strata vary from four to seven feet in height above the river, and are overlaid by heavy beds of whit- ish and mottled clay. Similar strata recur, at inter val<<, in ascend- ing the river, rising to greater elevations, and presenting a greater abundance and variety of fossils as we proceed.

Below Woodstoeh, the banks gradually decline, and on the side of a little creek or gnt between this and Mathiass Point, the Eocene strata entirely disappear. To the east of this creek, and at the point, the banks rise to twenty or twenty-five feet, and consist of yellow- ish and reddish c1ay<>, containing no trace of the green sand or. fosis of the Eocene. Still further down, the cliffs are replaced by a low and retiring shore, beyond which the beds of Meiocene marl first come in view.

It is obvious from these details, that the eastern limit of the

Eocene is niBrked on both rivers by the oootirrenoe of a region of like geological and topographical features, immediately east of it, and by great similarity in the arrangement and composition of the coDtignons strata. As on the James .and Pamnnkey rivers, as well as in the district of which we are now treating, the Eocene is skirted on the ease by a level and comparatively low district, com- prising only beds of sand and clay, destitute of fossils, it would seem a probable conclusion that these barren strata mark the period of disturbance which terminated the epoch of the Eocene deposits, a period attended with such important changes in the con- dition of the neighbouring seas, as to destroy all, or nearly all, the species of shell fish then inhabiting them, and to adapt their waters to that multitude of new species which were brought to light in the succeeding epoch of the Meiocene.

Between the two points thus fixed upon as the extremities of the eastern boundary of the Eocene in the neck, several intermedi- ate localities have been marked, but from the obscurity of the ex- posures, no very certain indication could bo derived as to the pre- cise figure of the boundary line in the intervening space— there is little doubt, however, that it will be found to depart but in a very slight degree from the right line connecting the two points above described.

The western boundary of the Eocene remains next to be de- scribed. In drawing the line of demarcation here, as in the former case, a few well-determined points are relied upon for fixing its general direction, and the intervening irregularities are not at- tempted to be laid down. Indeed, the absence of any satisfactory exposures of the strata, throughout a distance, sometimes of several miles, renders this the only method of proceeding at present prac- ticable.

The guiding points in fixing the western limits of the Eocene in the peninsula, are :

1st. The mouth of the Massaponax river, in Spottyltania county.

2d. A point a little east of Oray's mill, on Little Falls run, about half a mile above its mouth, and three miles southeast from Freder- ieJuburg, in Stafford county.

8d. The church on Potomac creek, a little above which the free- stone is largely exposed.

4th. A point a little below Brook's mill, on Accnkeek creek.

6th. A point on Acquia creek, about one mile below the month of Austin's run.

6th. The mouth of Still House branch, on Meadow branch, and a point on the Potomac about one mile above the mouth of the latter.

An inflected line passing through these points, will present a close approach to the western boundary of the Eocene in this part of the state. At the same time, in certain local instances, the marl is observed in positions somewhat west of the margin thus deline- ated, existing either as an outlying patch in the midst of the ad- joining formation, as in the small tract lying a little southeast of

Stafford conrt-Lonse, or as portions of a narrow tongue entering westward of the main boundary of the marl, as in the case of the Eocene deposits observed at Thrashly's farm, and within a mile of FredericJc9hurg.

On the west side of the month of Massaponax, the freestone, which constitutes so valuable and interesting a feature in the geology of this district, terminates; and at a short distance below, Eocene strata come distinctly into view. Where the main road leading down the Rappahannock crosses the Massaponax, the greenish yellow bed, which frequently forms the highest stratum of the Eocene, may be plainly discerned in the hill side, its clayey tex- ture turning off the water, which makes its escape along its upper surface.

On Snow creek, on the edge of Spotsylvania county, and less than a mile to the east of Massaponax, several extensive exposures of the Eocene occur. Near the point at which the road before mentioned crosses the creek, a bank of from thirty to forty feet in height exhibits the following series :

ist. A dark bluish green stratum, containing a little sulphate of lime, a considerable portion of green sand, and a great many shellfl, among which are Eocene Cardita, Cytherea and Turritella.

2d. Stratum of greenish yellow, and somewhat micaceous clay, containing some sulphate of lime, and a little sulphate of iron, or copperas.

8d. Stratum of a yellowish brown mixture of clay and sand, with ferruginous markings, indicating the former places of shells. This contains a small amount of sulphate of lime.

4th. An upper bed of diluvial sand and gravel.

On the same stream, nearer the river, and at the base of the first low grounds, another exposure occurs, which, from the peculiar condition of the fossils it contains, merits a description in this place. The strata are as follows :

Ist. A layer, consisting of common and green sand, the latter in remarkably large grains, and amounting to more than twenty per cent, of the whole. A striking feature in this stratum is the im- mense number of fossils, principally Cytherea ovata, and Turritella Mortoni, which it contains in the modified condition before de- scribed. The shelly matter has almost entirely disappeared, and its place is now occupied by oxide of iron, of a deep brown colour, presenting the most perfect casts, both of the interior and exterior of the shells. This bed contains a notable proportion of green sand, a little Mica, and some sulphate of lime and of iron. Its thickness is about eight feet.

2d. A stratum of yellowish white sand, variegated with numer- ous bright yellow blotches, faintly representing the figures of the shells which they have replaced. These blotches are principally composed of oxide of iron. The chief material of this bed is com- mon siliceous sand, containing a few scattered granules of green sand. Its thickness is about twenty feet.

8d. Diluvium, containing coarse gravel, and some large pebbles.

On the Accakeek, near Mr. BtooVb the Eocene and Sandstone are seen at verj contignons points, both presenting exposures of considerable extent. The marl here coniists chiefly of shells em- bedded in a dark olive brown clay, containing a portion of green sand. The shells are cltiefly Oytberea lenticularis and Ostrea sellas- formis or the Saddle Oyster, with a few Venericardia asoia. At Mr$. KolWs on Acquia creek, about two miles below the month of Anstins mn, the marl is finely exposed in an abrupt cliff. Here fine specimens of fossils, comprehending Tnrritella, Gy therea, Craa- satella and Ostrea may be procured. The material in which they are embedded, is a friable mixture of sand and clay, of a light yel- lowish brown colour, blended with green sand in grannies of unusu- ally large size.

In thus drawing an outline of what may be termed the western coast of the £ooene formation, as already remarked, the peculiar ir- regularitiea observed at several points in the actual boundary, will occftrion considerable discrepancies between it and the line above described.

Besides such flexures as may have originally existed in this line at the period of the deposition of the Eocene, great additional ir- regularities must have been produced by the destructive agencies which subsequently operated. The region in which the Sandstone and Eocene formations are brought together, is marked by the ef- fects of violent diluvial action. Coarse gravel, pebbles and bowlders bestrew the surface, and mingle to considerable depths with the sandy strata usually found upon the heights. Deep and precipitous ravines, connected with the valleys of the creeks leading into the Potomac, attest the energy and extent of the aqueous forces once operating over this region, while the confused mixture of materials, by which the usual upper stratum of the Eocene is often seen to be replaced, indicates the power of the denuding and transporting agencies to which that formation must at one time have been ex- posed. It is thus that many places within the general confines of the Eocene, bared of their former covering, now merely expose the underlying beds of freestone, while at other points, not immediately in the line of the violent action of the diluvial wave or current, the incumbent beds of marl remain in place.

Moreover, there is reason to believe that the sandstone is spread out towards the east, below the Eocene strata, nnd that its depth alone conceals it generally from the view. Where, therefore, in consequence of some local irregularity of its surface, it was less deeply buried, we might naturally expect, even at some distance within the confines of the Eocene to see its upper stratum exposed to day.

Section TIT.

Arrangement and CompoHition of the Meioccne Strata of the Penimula {of Northern Neck. Ed.),

The strata composing the Meiocene in this portion of the state, are in general analogous in arrangement and materials, to those of

Stafford court-boase, or as portions of a narrow tongue entering westward of the main boundary of tbe marl, as in the case of the Eocene deposits observed at Tbrashljrs farm, and within a mile of Fredericksburg,

On tbe west side of tbe month of Massaponax, tbe freestone, which constitutes so valuable and interesting a feature in the geology of this district, terminates; and at a short distance below, Eocene strata come distinctly into view. Where the main road leading down the Rappahannock crosses the Massaponax, the greenish yellow bed, which frequently forms the highest stratum of the Eocene, may be plainly discerned in the hill side, its clayey tex- ture turning oft the water, which makes its escape along its upper surface.

On Snow creek, on the edge of Spotsyltania county, and less than a mile to the east of Massaponax, several extensive exposures of the Eocene occur. Near the point at which the road before mentioned crosses tbe creek, a bank of from thirty to forty feet in height exhibits tbe following series :

1st. A dark bluish green stratum, containing a little snlphate of lime, a considerable portion of green sand, and a great many shellfl, among which are Eocene Cardita, Cytherea and Turritella.

2d. Stratum of greenish yellow, and somewhat micaceous clay, containing some sulphate of lime, and a little sulphate of iron, or copperas.

8d. Stratum of a yellowish brown mixture of clay and sand, with ferruginous markings, indicating the former places of shells. Thia contains a small amount of sulphate of lime.

4th. An upper bed of diluvial sand and gravel.

On the same stream, nearer the river, and at the base of the first low grounds, another exposure occurs, which, from the peculiar condition of the fossils it contains, merits a description in this place. The strata are as follows :

1st. A layer, consisting of common and green sand, the latter in remarkably large grains, and amounting to more timn twenty per cent, of the whole. A striking feature in this stratum is the im- mense number of fossils, principally Cytherea ovata, and Turritella Mortoni, which it contains in the modified condition before de- scribed. The shelly matter has almost entirely disappeared, and its place is now occupied by oxide of iron, of a deep brown colour, presenting the roost perfect casts, both of tbe interior and exterior of the shells. This bed contains a notable proportion of green sand, a little Mica, and some sulphate of lime and of iron. Its thickness is about eight feet.

2d. A stratum of yellowish white sand, variegated with numer- ous bright yellow blotches, faintly representing the figures of the shells which they have replaced. These blotches are principally composed of oxide of iron. The chief material of this bed is com- mon siliceous sand, containing a few scattered granules of green sand. Its thickness is about twenty feet.

8d. Diluvium, containing coarse gravel, and some large pebbles.

On the Aocakeek, near Mr, BroohB, the Eocene and Sandstone are seen at very contiguons points, both presenting exposures of considerable extent. The marl here consists chiefly of shells em- bedded in a dark olive brown clay, containing a portion of green sand. The shells are chiefly Oytberea lenticahiris and Ostrea sellaa- formis, or the Saddle Oyster, with a few Venericardia ascia. At Mr*. RoWs on Acqnia creek, about two miles below the month of Austin's run, the marl is finely exposed in an abrupt cliff. Here fine specimens of fossils, comprehending Turritella, Cytherea, Cras- satella and Ostrea may be procured. The material in which they are embedded, is a friable mixture of sand and clay, of a light yel- lowish brown colour, blended with greeti sand in granules of unusu- ally large size.

In thus drawing an outline of what may be termed the western coast of the Eocene formation, as already remarked, the peculiar ir- regularities observed at several points in the actual boundary, will occasion considerable discrepancies between it and the line above described.

Besides such flexures as may have originally existed in this line at the period of the deposition of the Eocene, great additional ir- regularities must have been produced by the destructive agencies which subsequently operated. The region in which the Sandstone and Eocene formations are brought together, is marked by the ef- fects of violent diluvial action. Coarse gravel, pebbles and bowlders bestrew the surface, and mingle to considerable depths with the sandy strata usually found upon the heights. Deep and precipitous ravines, connected with the valleys of the creeks leading into the Potomac, attest the energy and extent of the aqueous forces once operating over this region, while the confused mixture of materials, by which the usual upper stratum of the Eocene is often seen to be replaced, indicates the power of the denuding and transporting agencies to which that formation must at one time have been ex- posed. It is thus that many places within the general confines of the Eocene, bared of their former covering, now merely expofie the underlying beds of freestone, while at other points, not immediately in the line of the violent action of the diluvial wave or current, the incumbent beds of marl remain in place.

Moreover, there is reason to believe that the sandstone is spread out towards the east, below the Eocene strata, nnd that its depth alone conceals it generally from the view. Where, therefore, in consequence of some local irregularity of its surface, it was less deeply buried, we might naturally expect, even at some distance within the confines of the Eocene to see its upper stratum exposed to day.

Section JIT.

Arrangement and Composition of the Mevocene Strata of the Peninsula (of Northern Neck, L'd,),

The strata composing the Meiocene in this portion of the state, are in general analogous in aiTangcment and materials, to those of

the same formation, in the peninsnla of the James and York rivers, as described in my first report, and indeed preserve a close resem- blance to those of the region south of James river, systematicallj treated of in the report of last year.

The two interesting general facts of the occurrence of the bluish marls low down in the series, and the presence of a thin band of ferraginous rock or clay on the top of the marl, and between it and the diluvial strata, are not less distinctly observable here than in the regions formerly referred to. Indeed, so uniform is this posi- tion of the band of iron rock, in regard to the beds of marl, that the discovery of this material, at any pointy would furnish strong grounds for believing that the fossiliferous strata existed at some depth beneath.

As another feature of correspondence between this and tlie dis- tricts previously described, I may mention the occurrence of the fragmentary marl along the eastern boundary of the Meiocene ter- race, where it subsides abruptly into the low flats immediately adjoining the bay shore. On the Curratoman river, and at other points idong this escarpment, the rocky marl, consisting of water- worn fragments of shells, more or less firmly cemented together, is in all respects analogous to that described in previous reports, as forming the material of the edge of the Meiocene terrace between the Rappahannock and James rivers, and for some distance south- wards of the latter, so that we may regard this curious demarcation of one of our ancient coast lines as continuous from the Potomac river to near the Carolina border.

In general, the blue marl is observed to be the richest in fossils, and is hence found most available in agriculture. In many places, however, especially towards the eastern termination of the penin- sula, the shells occur in sand and clay of various shades of yellow and brown, in snfBcient proportions to form highly valuable marls.

In addition to the fragmentary rock, above referred to, consist- ing of broken shells, cemented by carbonate of lime, sometimes partially crystallized, the white, pulverulent and chalk marls, are found in extensive beds on Curratoman river and Carters creek, west of the termination of the higher level of the neck.

In general, the upper beds of the Meiocene, in this district, are destitute of fossils, though full of their casts and impressions. These strata, consisting, for the most part, of light coloured sandy clays, frequently of great depth, are distinguished by a sulphureous smell, and an acid and somewhat styptic flavour. They rarely con- tain any considerable amount of carbonate of lime, presenting, in its stead, variable, and sometimes valuable proportions of the sulphate, together with sulphate of iron, sulphate of alumina, free sulphuric acid, sulphur, and sometimes even an appreciable quantity of sul- phate of magnesia.

The acidity of these clays is often sufficient to make a pungent impression on the tongue, and their sulphur is distinctly recognized by the characteristic odour they exhale, especially when gently warmed.

In many localities, the Gypsnm oconrs in crystals of safficient niagnitade to be readily separated by the fingers, and sometimes even in the attractive form of transparent Selenite ; bat the more usual condition, is that of delicate silken crystals distributed through the mass, and visible only upon close and attentive inspection. The Sulphates of iron and Alumina, are occasionally observed in the form of an efSorescence, upon the surface of the strata, and the Gypsum likewise presents itself, under similar circumstances, as a white incrustation.

Minute silvery scales of Mica are met with in nearly every stra- tum, but abound most in those of a bluish or greenish tinge.

The fossil impressions contained in these beds are, in general, beautifully distinct, and appertain to all the species of shells which are found in perfect condition in the sabjacent strata. In some cases the overlying band of iron stone is not less richly fraught with them than the layers beneath, and from its hardness and in- solubility, has preserved the most delicate markings of the shells in all their original sharpness. In many localities, the impressions of the fossils in the clay or sand, are beautifully bronzed by a thin film of oxide of iron, which has taken the place of the material of the shell ; but in others a vacancy seems to exist in the space origi- nally occupied by the calcareous matter, so that the interior casts of the fossils, formed of the general substance of the bed, may often be extracted in great numbers in a perfect condition.

In the blue mar), as well as other strata containing fossils, in the neck, there is often present a notable portion of green sand, and at some localities of the Meiocene, this material is found mingled pretty largely with common sand and clay, in strata in which no fossils can be found. Besides the overlying band of ferruginous rock before described, there occurs, in some places in the neck, another similar stratum, nearly on the top of the diluvium. This, of course, presents no marks of organic remains, and is generally but an aggregation of coarse gravel and sand, cemented by ferrugi- nous matter.

Seotiow IV.

Description of some of tTie more Interesting Localities in the Meio- cene District of the Peninsula {of Northern Neck. Ed,),

To give clearer conceptions of the arrangement and character of the strata, of which a general sketch has just been presented, a de- tailed account of them, as exhibited at several of the more impor- tant localities in the neck, will now be introduced. Details of this description, whilpt they furnish the scientific enquirer at a distance, with that precise information, in regard to the geological structure of the region, which he is chiefly interested to obtain, are not unat- tended with advantages of a more practical kind, by affording to all who are directly interested in the resources of a district, an easy means of examining them for themselves.

STUATFOBD AND CriAHTlLLY OLITM.

These noted cliffs, sitaated in WeitmoreJand county, extend along the Potomac for several miles, ou both sides of the mouth of ChantUly creek, rising, in some places, to an elevation of about one hundred feet, and in others subsiding to lower levels, or sinking, for a short space, into the ordinary river flats. At a point a little above the mouth of the creek, what are properly termed the Stratford cliffs, begin. Thence they continue up the Potomac, with but lit- tle interruption, for about four miles. For some distance from their lower termination, they present the following order of strata :

1. At the base, and extending to the height of from fifty to sev- enty feet, a stratum of blue sandy clay, containing impressions of shells of several different kinds, among which the Pecten Madiso- nius, Venus mercenaria, Venus oortinaria, and Mactra modicelUi, are the most frequent. Upon the surface of this clay, espeicially where it projects from the general cliff, a copious efflorescence of sulphate of iron is usually found, imparting a greenish yellow col- our to the surface. At other more retiring parts of the chff, a white and somewhat granular coating of sulphate of lime, is equally abundant, and small silken crystals of this substance are generally disseminated through the materials of the stratum. On the surface of this bed, delicate crystals of sulphate of magnesia may likewise be discerned. This stratum is overlaid by a band of indurated ferru- ginous clay, approaching to the hardness of rock, and filled with a material closely resembling pipe-ore. This is about two feet thick. Next above is a stratum consisting, alternately, of sand and ferruginous mottled clay, extending to a height of about forty feet; and lastly, is a layer of diluvial gravel, covered with a shallow soiL

Further up the river the cliffs attain a greater elevation, being, in some places, about one hundred feet in height. Here the same strata occur, and in the same order as before. Proceeding still liigher up the river, a band of shells makes its appearance upon the face of the cliff, at a height of about fifteen feet above the water. This rises, as we ascend the river, with a gentle inclination, until at its northern extremity it is fifty or sixty feet above the beach. The width of this band is about five feet, and its length, though not without occasional interruptions, about one and a half miles.

The material of this stratum is a bluish sandy clay, very similar to that before described, but containing no appreciable amount of tbe various sulphates observed to be present in the former. The shells are very numerous and perfect. Among them are vast numbers of the Perna maxillata of small size, as well as Tnrritella plebeia, Mactra modicella, &c., with an occasional Area idonea, and other larger shells. Above this bed is a heavy stratum of clay, of a mottled appearance, and higher still, and distant about twenty feet from the former, a second fossiliferous layer of a lighter colour, and containing fewer shells. Among the various substances found in the strata of these cliffs, especially towards the lower extremity, are to be enumerated distinct and beautifully compact liguite and

fibrous carbonate of ]ime. The latter is found in the interstices of a yellowish day, forming the stratum next beneath the dilnyium, and is sometimes in sufficient quantity to render the clay quite calcareous.

An average specimen of the blue marl, from the lower of the two strata just described, yielded, in the one hundred grains, forty- four and three-tenths grains of carbonate of lime ; from the upper only twenty-one grains.

The Ohantilly cliffs, situated below the mouth of the creek of the same name, adjoining the ancient residence of Biehard Henry Lee, and about two miles fnrther down the river than those of Strat- ford, may be regarded as a continuation of the former, having the same average elevatioa, and being composed of very similar mate- rials. At this point, however, the fossuiferous stratum has much greater thickness, sometimes reaching from the waters edge to a height of nearly twenty-five feet. A less proportion of the Pema is presented in this bed, which principally consists of Mactras, and other small bivalves, together with several species of Pectens. The beach is strewed with fragments of ferruginous sandstone, which have fallen from the upper portion of the cliff, where a band of this material overlies the shelly strata of the Meiocene. These masses exhibit the impressions of Pectens and other shells, beautifully dear and sharp.

An interesting illustration of the fertilizing properties of some of the materials composing the Stratford and Chantilly cliffs, is deserving of mention in this place. Zones of vegetation, consisting of clover, together with scattered locust trees, may be observed at the proper season, extending to a great distance along the face of the cliffs, marking distinctly the limits of the marl or gypseous clay, and rarely encroaching upon the other strata. Even where the sur- face is almost vertical, this beautiful drapery is retained.

BANE OF THE rOTOlTAC BELOW THE MOrTII OF LOWER UACUODOO RITEB, IK

Westmoreland County.

At Coles Point, situated on the south side of the mouth of the Lower Machodoc, commences a low bank, wliich is prolonged for about one and a half miles down tlie river, at a pretty uniform ele- vation of fourteen feet. A few paces below the point, the following strata occur :

1. A layer two feet thick, consisting of a bright yellow mixture of sand and clay, abounding in shells of various kinds, among which are, Pema maxillata, Ostrea compressirostra, Venus mercenaria, V. cortinaria, V. paphia, Isocardia fratema, Pecten Madisonius, P. Jef- fersonius, Pectuuculus pulvinatus, Corbula inequale and Turritclla variabilis.

2. Next a layer six feet thick, composed of mottled ferruginous sand with a small admixture of clay, containing no shells, but abund- ant markings, as if shells had once been present in great numbers.

3. A band of iron sandstone three inches thick ; and

4. A dark mould, extending to the top.

In proceeding down the Potomac, the yellow marl is seen gradn- ally rising higher in the bank. A stratum of bine marl lying beneath it next comes in view, and this continues along the base of the bank, extending some distance out upon the beach, until the shore sinks into a low sandy flat at Ragged Point.

The Rappahannock cliffs in Richmond connty, nearly opposite to Westmoreland courthouse, extend along the river for abont foar miles at an average elevation of from forty to sixty feet. Through- out this long range of strata, but little variety is presented. Beds of sandy clay, of various shades of yellow, brown and greenish blue, extend from the waters edge to within a few feet of the top of the bank. In general, the first thirty feet consist of a dark greenish blue mixture of sand and clay, above which is a layer, six feet thick, of similar material, of a brown colour; next, a band, of twelve inches, of a ferruginous aspect, and over all a stratum of light col- oured flaky clay, coated with a yellowish and white incrustation of sulphate of lime. Fossils are rare in any of these beds, but malti- tudes of their casts and impressions may be found. These embrace a great variety of the smaller shells, some of them of species fre- quently met with. Spiculie of gypsum are distributed in the body of the clay, and are particularly numerous upon the surface and in the hollow of the casts, which, in general, are painted over with the brown oxide of iron. In many places sulphate of iron and sulphate of alumina eflioresce upon the surface, and sulphur is distinctly in- dicated.

Irregular nodules of ferruginous clay are found embedded in the other materiiils, presenting the curious feature of a crystalline nu- cleus, consisting of pure Selenite. In some portions of the cliff, these crystals are of considerable size, arranged in their usual star- like form, and so abundant as to suggest the utility of employing these clays in the agriculture of the neighbouring parts of the neck. An average specimen, taken from a part of the cliff where similar material was quite abundant, afforded by analysis, in the one hun- dred grains, ten grains of sulphate of lime.

BAirXS OF THE RAPPAHANNOCK ABOW THE MOUTH OF TUB CURRAT021AN RIVER,

Lakc Aster Count F.

In proceeding down the river from the neighbourhood of Bel- moot, the residence of 2>r. Jones, abont eight miles above the mouth of Curratoman, the cliffs for some distance present heavy beds of clay and sand, overlaid by the ordinary diluvium, and resting upon a stratum of soft ferruginous sandstone, graduating into a sandy clay, and sometimes a yellowish sand, mottled with ferruginous spots.

Following these strata for a distance of one and a half miles, we meet with a rocky layer, consisting entirely of shells, converted into brown oxide of iron, situated at the base of the cliff. This contin- ues in the same direction for a distance of one and a quarter mUes. The following is the order of the strata composing the bank at a point near its eastern termination :

1. Beneath the base of the clifif, as it is exposed, and as under- lying the beach sand, is a blae marl, containing numeroas shells, and having a sensible amount of green sand. These shells are chiefly Pema, and different species of Venus, Natica, and Oliva.

2. Running along the base of the bank, the ferruginated, shelly rock above described, four feet in thickness, and containing the some fossils as the stratum beneath.

8. Hve feet of sand, with ferruginous blotches and streaks.

4. Six feet of diluvium.

Below this, and within a short distance of the Gurratoman, marl beds occur below the level of the flats, consisting chiefly of a pecul- iar variety of the Ostrea Yirginica, of which a similar deposit exists on the opposite side of the Rappahannock. It is distinguished by the length and depth of the channel of the hinge in the one valve, and the large angular pivot-like protuberance in the other, as well as by the general elongated form of the shell.

Iiank Of Thx Sappahannock Frou Neab Ciierbt Point, Lancaster Countt.

At about one mile above Cherry Point, at Mr, Palmer* the bank consists of the following strata :

1. Forming the base of the clifl, and extending up about three feet is a blue clay marl, contiuning a great many shells. This layer reaches to some depth below, and extends out beneath the sand of the beach.

2. A bed of chocolate coloured clay, embedding a vast number of the variety of Ostrea Virginica, previously described. This is three feet in thickness.

8. A bed of partially decomposed Serpula, containing few other fossils, one foot thick.

4. A layer of ferruginous sandstone, in bands alternating with thin seams of sand. Three feet thick.

5. Ten feet of diluvium.

The above strata, in the order just described, continue down the river for the distance of half a mile, appearing to. dip gently towards the bay. The marl is then lost for about two and one half miles, after which it reappears, at intervals, as far down as Musquito Point. Here the country becomes a sandy flat, and so continues to the bay shore. In the interval of two and a half miles, where no marl is seen, the cliffs, which are from twenty to thirty feet in height, consist at the base of blue clay, containing impressions of shells; above this of ferruginous sandstone, or of ferruginous sandy clay ; the whole covered with a bed of diluvium.

Near the end of this line, a blackish, clayey substance rises into view from the base of the cliff, underlying the blue clay above mentioned. This gradually becomes more exposed upon the bank, .until it attains the height of four feet, after which it slowly sinks, and is again lost. The marl now makes its appearance, consisting of a blue clay, with little sand, and multitudes of shells. This reaches along the bank for about four hundred yards, when it ifl

sncceeded by a Bhell rock, in which the Bbelly fragments are almost completely replaced by brown oxide of iron. This continnes to near the end of the bank, which now subsides into the flat, extend- ing from Mosqaito Point to Windmill Point, on the bay shore.

LOOALXTT ONE AND A HALF HILBS EAST OF LA9CA8TEB OOVBTUOVBE (iCB. BXS/A-

MIN walker's).

This exposure, which is in a ravine on the ridge of the neck, presents the following strata :

1. A bed of blue marl, containing great numbers of shells, many of which are of the larger species. The depth of this stratum is not known.

2. A similar stratum of a rather lighter colour, and containing chiefly the small shells. Three feet thick.

8. A layer of ferruginous matter, abounding in the casts and im- pressions of shells. These casts are usually found in the interior of spheroidal nodules, or geodes of oxide of iron, and consist of this oxide replacing the shelly matter, and covered with a beautiful shin- ing covering of the carbonate or velvet iron ore. This bed is four feet thick, and reaches to the surface.

LOCAUTT FOUB IHLES BOCTIIWEflT FXOX NORTH UMBEBLAirD OOUBTnOOBB (iTR.

OEOROE booth's).

This exposure is in a hollow, about twenty-five feet below the level of the ridge. The strata are :

1. A layer of greenish blue marl, containing a notable amount of green sand, in spots and blotches, and sometimes almost unmixed with other materials. This stratum has been penetrated five or six feet, and is believed to extend to a much greater depth. The shells are in a state of remarkably perfect preservation, and pre- sent an unusual variety of species, belonging to the genera Venus, Pecten, Pectunculus, Mactra, Crassatella, Astarte, Ostrea, Oorbula, Turritella, Oliva, Fissurella, and others. Their interior is filled chiefly with the green sand.

2. A layer of ferruginous sandstone ; and 8. A stratum of diluvium.

locality of cockle-shell BRANCIT, K0BTHV3IBERLAKD COUNTY.

Here the strata are :

1. A bed ot marl, consisting of common sand mixed with green sand, and containing a large number of shells.

2. A layer of a bright {zreen, indurated sandy clay, approaching to the hardness of rock, and containing innumerable impressions of Yenerioardia granulata, Pectunculus pulvinatus, and P. subovatns, and other shells of rare dclicac'y and beanty, but entirely devoid of the shells themselves.

8. A bed of common sand, largely mixed with green sand.

4. A layer of sandy clay, with markings resembling sheila.

5. Diluvium.

IX>CALITr TWO Ain> A HALF MTLX0 ABOVE THS VOUTH OF HULLS OBXXK, KOBTH-

Cmbbbi.A1Io Couhty.

1. At the base of the steep bank of the creek, and within a few inches of the waters edge, occars a ledge.of ferruginons rook con- taining an immense number of shells, closely cemented together, as well as the casts of similar fossils. These are chieflj Pema max. Yenos and Pecten. This ledge is two feet thick.

2. A stratum of yellowi:)h sandy clay, of the same thickness, abounding in Pema max, in a very friable condition.

8. A light blue marbled day, ten feet.

4. Coarse dilnyium.

The foregoing detailed account of various localities in the neck, will, it is hoped, give a correct idea of the generally prevailing order and fossil contents of the Meiocene strata in this district, and at the same time exemplify the principal varieties presented in them, as regards the nature of the earthy materials, including the shells, or their casts, as well as the conditions of the fossils them- selves.

Of the numerous other localities which have been minutely ex- plored, embracing almost every exposure of the Meiocene in the peninsula, it is therefore needless to give any description in this place.

In the extensive area of flats, already described as reaching from tlie foot of the ridge, of which SprUe Hill is the northern end, to the bay shore, beds of marl have hitherto been disclosed only at a few points. On the land of W. Tomlin, esq, near Kilmamoeiy blue and yellow marls have been found in several places, a few feet be- neath the general level of the flat, and it is particularly worthy of remark, that the fossils furnished by these shallow diggings, are those usually found in the Meiocene of the neck, such as Ostrea compressirostra, Pectunculus pulvinatus, and P. subovatas, Mactra modioella, &c. thas indicating the prolongation of the Meiocene strata to the very extremity of the peninsula.

Section V.

Of the FomU of the Meiocene Marl,

The shells enclosed in these strata are usually in good preserva- tion, though generally so friable as readily to fall to pieces when spread upon the ground. They are commonly found in groups or colonies, and frequently, throughout an extensive exposure, only one or two species can be met with. This is strikingly the case with the beds containing Pema, of which a fine example is pre- sented in the Stratford cliffs, as formerly described. It is perhaps still more remarkable of certain strata of blue marl, found on the Potomac, at the point above named ; upon the Rappahannock in several places, and at some localities in the interior. This marl presents a beautiful aggregation of very pei*fect small shells, (Mactra

modicella,) boand together bj a rather teoaoions blae clay, and rarely exhibits a speoimen of any other species. The aboudanoe of this fossil in the blue marl iu corresponding parts of the Meio- cene tract towards the sooth, and especially on the sonth side of James river, has been particularly noticed in preceding reports.

The shells most nsnally presented in the marl beds of the neck are as follows :

Pecten Jefferson! us, scallop. Pectnnculas soboyatna.

Pecten Madisonias. Peotnncalas pnlvinatoa.

Ostrea compressirostra, marl Pema mazillata.

oyster. Isocardia fratema.

Ostrea Virginica, marl oyster of Artemis aoetabnlnni.

small size and different shape. Area idonea.

Grassatella Marylandica, marl Area stiilioidlnm.

oyster. Area centenaria.

Crassatella melino. Area incile.

Mactra delambis. Venus meroenaria.

Mactra confraga. Venus deformis.

Mactra modicella. Veuns cortinaria.

Chama corticosa. Astarte nndulata.

Ghama oongregata. Astarte vicina.

Venericardia grannlata. Tnrritella aiticosta.

Fusus qnadnoostatns. Turritella plebeia.

Fosus parilis. Serpula granifera.

Fulgur carica. Crepidula costata.

Turritella ter-striata, Buccinum IsDqneatnm.

Sbotiok VI.

Arrangement and Compontion of the Eocene Strata of the Pei

inmla.

But little uniformity preyails in the arrangement of these beds, as observed at different localities. In general, the lowest stratum of the series is of a dark greenish blue colour, and those which lie above it bave various shades of yellow, greenish, grey and brown. In many instances, the upper stratum is devoid of shells, but replete with their casts and impressions. Frequently, it is more or less impregnated with sulphates of lime, iron and alumina, which im- part to it a styptic or astringent flavour, and with a small amount of snlplior, recognized by the odour it exhales when heated. All these ingredieuts, however, enter into the lower beds, though in less proportion, and are not excluded from strata containing ells. A thin band of ferruginous gravel, sometimes partially cemented, frequently overlies these beds, and forms the boundary between them and the Meiocene. We thus see a striking correspondence in the situation and condition of these and the upper Meiocene strata, and we infer that chemical agencies of a like nature have operated upon both.

8xonoN VIL

Zoealities the Potamae,

Extensive and valuable exposures of the Eocene are met with on this river. These strata first shew themselves a little above the month of Acqnia creek, and continue, with but few considerable interruptions, as far as the eastern boundary of this deposit, at Ma- thiass Point.

Throughout much of this distance a portion of the niarl has the character of a hard rock, of a yellowish white or greenish grey ap- pearance, abounding in shells and their impressions. The lighter coloured variety is edways more or less specked with green sand, in rather large granules, and the darker contains this substance in larger quantity, nniformly diifiised throughout the mass. The ma- terial enclosing the fossils, or their casts, consists largely of carbon- ate of lime, acting apparently as a cement. This rock may there- fore be regarded as an booxnb umxstone.

At a point about a quarter of a mile below the mouth of Acquia creek, the cliff, having a height of forty feet, exposes the following strata:

1. From the water to the height of twelve feet, is a yellowish grey marl, specked with green sand, and abounding in shells, chiefly Gytherea ovata and Crassatella capricranium.

2. A ledge of rock, three feet in thickness, closely resembling the marl in colour and composition.

8. A layer of sandy clay, of a sulphur colour, containing shells, principally Turritella Mortonu This is five feet thick.

4. A stratum of yellowish clay, enclosing impressions of Turri- tella, &c., and impregnated with the snlphates. This is twenty feet thick. Abont midway between the raoutlis of Acquia and Potomac creeks, the bank has an elevation of about fourteen feet, and con- sists of:

1. A layer of dark greenish blue marl, very remarkable for the multitude of shells, principally Crassatella, which it contains. This rises only one foot above the water.

2. A bed of shell rock, resembling the stratum beneath, but very hard, one and a quarter feet thick.

8. A layer of yellow sandy clay, containing Turritella Mortoni and other shells. This is at least seven feet in thickness, and is capped by a thin stratum of yellow clay.

In proceeding downwards, the shell rock, dipping gently to the east, becomes lower in the bank, and at length disappears near the mouth of Potomac creek. The bluish marl continuing beneath, first passes out of view.

The greenish blue marl again comes in view at the landing on the south side of Potomac creek, and still further down, at about half a mile below the month of Paspitansy creek, the bank of the Potomac presents :

1. A stratum of this dark coloured marl, seven feet thick, eon-

taining some green sand and nnmerons shells, chiefly TarritelU Mortoni, Orassatella capricraninm and Ostrea sinuosa.

2. A hed of yellowish and reddish day, thirteen feet thick.

A little below this point, a ledge of the shell rock makes it ai>- pearance in the bank, and continues, with bnt little intermption, down the river for seyeral miles.

At some points two of the ledges are seen : one near the water level, and one at a considerable height on the face of the bank. This rook is replete with fossils and their oasts, and oonsista, in large part, of carbonate of lime. In the same bank the marl is seen in the softer condition, and of both the yellowish and greenish blue yarieties, overlaid by a stratum of the gypseous and acid clay. Among the interesting fossils here found, are two beantifol species of GncuilflBa.

At the Eaglets Nest and Mount Stnart, about three miles above Boyds Hole, the Eocene strata are well exposed for some distance along the river bank.

At the former locality, the banks, which are from twenty to twenty-five feet in height, are composed of two strata : the lower, which is about twelve feet thick, consisting of dark bluish clay and sand, strongly imbued with copperas, and containing a little gypsum; and the upper, of coarse ferruginous sand and gravel. A few hun- dred yards below this point a thin layer, containing fossils, comes in view about midway between the top and bottom of the bank; and as we proceed down the river, this shelly stratum expands in thickness, its upper boundary continuing horizontal, while its lower limit approaches the level of the beach. At a point about four hundred yards below the beginning of this layer, the strata are as follows :

1. Blue clay, one foot in thickness.

2. Shelly stratum, seven feet thick, indurated in some places so as to form a rock. This abounds in fossils, among which Carditas are most numerous.

8. Blue clay, containing copperas, and shewing ferruginous stains. Three feet thick.

4. Clay and sand, in part diluvial. Seventeen feet thick.

For upwards of half a mile below this, the bank presents the same series, the marl occasionally, at base a stratum from four to seven feet thick, consisting of blue clay, sometimes fossiliferous, and sometimes without shells, covered by a bed of ferruginous sand and clay of varying thickness.

At Boyds Hole, the shelly stratum is not seen, but further down, especially at Albion, and the other localities near Mathiass Point, before described, it again makes its appearance in the clififs, and fur- nishes marls of a very useful quality.

On the Rappahannock, opposite Port Royal, at IT, St. L. Car- ters, and other localities on and near this river, the Eocene occurs, under circumstances very similar to those which have been described. In the interior of the peninsula, these strata are revealed in many places at the bottoms of the deep, ravines, and in general consist of

the dark greenish blae stratnm, oontoiDing shells, overlaid by a bed of the gjpseoas and copperas clays. Frequently, however, only this latter bed is exposed in these situations, and some digging becomes necessary to reach the layer containing shells.

Towards the western limits of the Eocene, the shell rock very frequently presents itself, and together with the other strata of the formation, generally attains a greater height than in the localities further to the east.

CHAPTER m.

THE yARROW BELT EXTEJTDTNO ALONG THE EASTERN MARGIN OF THE PRIMARY FROM PETERSBURG TO THE POTOMAC RIVER,

Sbotion I. Of the Formation met with in this Belt.

The tract here referred to, though in general narrow, and often but yagnely defined, claims a separate consideration, as well on ac- count of the interesting characters of the sandstone formation in- cluded within its limits, as by certain local peculiarities presented in the Tertiary strata by which, at various points, this formation is overspread.

As mentioned in my report of last year, the primary rocks, in many places near their eastern boundary, are seen to be overlaid by a peculiar species of sandstone, in general characterized by con- taining a large proportion of white felspathio earth, whose imperfect cementing power imparts a soft texture and rather loose aggrega- tion to the mass, and in some instances, leaves it in the condition of a bed of slightly adhering sand or pebbles. Though extensively ex- posed at various places on the Potomac, Rappahannock, North Anna, South Anna, James and Appomattox rivers, and on many of the minor streams, and in inland situations, these strata exhibit only at a few localities the peculiar vegetable impressions they con- tain in a sufficiently preserved condition to be of value in decid- ing upon the geological epoch of their formation. For the most part, these relics of a former vegetation are in the condition of charcoal, or of Lignite, sometimes approaching closely to a bitumin- ous coal, and in these cases the markings are too vague to ad- mit of identifying the vegetable forms to which they belong.

In some instances, however, very distinct impressions have been met with, unequivocal in character, and of such a nature as clearly to shew that tlie sandstones in question were deposited during a comparatively late period of the series of secondary formations, and are to be regarde<1 as of more recent production than the vari- ous slates, shales, sandstones and conglomerates, described under the name of the middle secondary formation in my last yearns re-

port. They may, therefore, for the present, with great propnecy, be designated as the upper secondary sandstones.

As indicated in the section inclnded in the report of last year, and as mentioned particularly in the body of the report itself, we find in many localities resting immediately upon this upper second- ary sandstone a succession of strata belonging to the Tertiary for- mation, consisting in some cases of the Eocene alone, and in others, including also superincumbent Meiocene.

As might be supposed, these overly ing Tertiary beds are almost entirely confined to the eastern margin of the region occupied by the upper secondary strata, where, in virtue of the easterly dip of the sandstone, its surface is sufBciently depressed to admit of the Tertiary resting above. In the few instances, as in the locality at Stafford courthouse, referred to under a former head, where the Tertiary is met with at some distances within the general margin of the sandstone, it occupies but small surface and appears to be in shaUow cavities, and marginal indentations of subjacent formation.

The Tertiary beds thus met with adjoining the tract of sand- stones, though often replete with the casts and impressions of shells, scarcely ever retain any of the original shelly material; which in most cases, has evidently been removed by the dissolving agency of the free sulphuric acid with which the surrounding sands and clays here, as in many other parts of the Tertiary region, are found even at the present time to be strongly imbued.

The peculiar feature of these Tertiary beds, in view of which I have proposed devoting to them a distinct consideration, consists in the occurrence of a very remarkable stratum varying from twelve to twenty-five feet in thickness, composed almost entirely of microsco- pic fossils between the beds containing the Eocene and those con- taining the Meiocene impressions.

This stratum which will be more particularly described under a subsequent head, giving no indications to the naked eye, or even under an ordinary microscope of its real composition, was until re- cently regarded by me as nothing more than a clay of unusually fine texture, such as is not unfrequently met with in the group of Ter- tiary strata. Nor was its true nature unfolded until struck by its remarkable lightness and its almost exclusively siliceous composi- tion, and adverting to the recent discoveries of microscopic fossils in Europe I was led to inspect it through a powerful microscope, when I found it to be made up almost entirely of exquisitely minute and delicate organic remains.

These curious relics, too minute to be described by the most penetrating eye, thus accumulated- in compact form into a stratum of great thickness, belong to a class of objects, which of late years have excited much attention in Europe from having been found to constitute an important portion of the mass of extensive beds of earth and rock, and are in fact the shells and sheaths of various species of animalcnl®, analogous to those which are met with in countless numbers in the waters of pools and marshes and in the sea, and which are denominated lvfu9(yry Animah.

Until the recent researches of the celebrated Ehrenberg dis- closed the important agency of these minute beings in the produc- tion of some of the mineral masses belonging to former geological eras, as observed in Europe no one had ever dreamed of finding whole strata of great thickness and extent, literally made np of these shells and other solid appendages ; yet nothing is more cer- tainly established than that these remains form not only the princi- pal material of the light white earth which is known gradaaUy to accnmolate in peat-bogs and in other moist situations, of the Leaf Tripoli found in many parts of Germany in widely extended beds of many feet in thickness, of the Semi- Opal and other dense products met with in these beds, and of the common gun-flint found in lay- ers of nodules running through strata of chalk, but that they com- pose in the shape of calcareous, as well as siliceous shells, and es- pecially the former, nearly the whole substance of the vast strata of the chalk itself overspreading extensive districts of Europe to a depth in many places of several hundred feet I

In view of these interesting facts, the discovery of the Infiisory stratum above referred to, as one of the members of our series of Tertiary deposits, cannot fail to be regarded as an important addi- tion to our knowledge of the Tertiary of the country, and has the greater interest at present, from being the first example yet ob- served in the United States, of the occurrence of Infusorial remains in any but the most recent geological formations.

The most extensive developments of this stratum hitherto met with, are presented in the hills in the immediate vicinity of Bieh" mond ana on the north bank of the Rappahannock river, in the neighbourhood and for some distance east of the eastern boundary of Uie Eocene on that river. The latter locality already alluded to, in connection wit the geology of the Northern Neck, not lying within the tract of which I am now treating, does not properly claim to be described under the present head, and from having been visited long before the existence of Infusorial remains in our Ter- tiary was even suspected, will merit further and more minute ex- plorations.

Ck>nfining my remarks, therefore, chiefly to the former locality, and reserving a particular account of the latter, and such others as may yet be described tor the final report, I proceed to treat, in order, first of the Upper Secondary sandstones and conglomerates, and secondly, of the Infusorial stratum and its as-tociated Tertiary beds, found resting upon the Upper Secondary in the neighbourhood of Riehfnond,

Section II.

Poiition. and Extent of the Arecu oeevpied hy Upper Secondary

Sandetones and Conglomeratee,

SKKTGU or TBS BOUITPABIXS OV TBX8 OBOUP OF BOCKB.

In attempting briefiy to indicate the limits of the several areas occupied by these strata, I propose merely to give such an outline

as by reference to the state map, will suffice to convey a correct im- pression of their general position and extent, without pretending to follow the boundary lines in all the various flexures through which they have been traced, and which are only capable of satisfactory exhibition by suitable delineations on the map itself.

The general direction of the tract in which these strata are developed, being marked by the eastern margin of the primary rocks, approaches closely to a meridian line passing through Peten- hurg, Richmond and FredericMurg, bending a litUe eastward as it extends from the Rappahannock to the Potomac river. In this re- spect it is strikingly distinguished from the belt occupied by the middle secondary rock, which as described in my last year's re- port pursues a general direction very nearly parallel to that of the Blue Ridge, and therefore nearly from northeast to southwest.

The narrow tract, extending from the Potomac to the Appomat- tox near Pet&rsbtirg in which the upper secondary sandstones are found, is not occupied by these strata throughout its whole extent. For much of the distance between the Rappahannock and North Anna rivers they cease to be disclosed within the artificial cuttings tliat have been made in this region or on the banks of the streams. But north and south of this deficient district tliey are met with, amply exposed, and have been traced continuously over areas of very considerable extent.

The more northern of these upper secondary tracts skirts the Potomac river from the upper extremity of the cliff at Mount Ver- non, which marks the northern termination of the formation, to a point a little above the mouth of Meadow branch. At various points throughout this distance, the sandstones shew themselves in the river cliffs, extending in some cases to a considerable height above the beach. In the bank at Mount Vernon, that near White house, at Hight Point, Freestone Point, at the mouth of Qnantico, as well as several intermediate places, they are well exposed, as shewn in the cliff at Freestone Point. Its thickness is between 60 and 70 feet

Leaving the river bank at the point above indicated, the eastern margin of the tract crosses Meadow brancii a little above the mouth of Still House branch, and bending around to a due south line, in- tersects Acquia creek, nearly half a mUe below tibe mouth of Aus- tin's run, and Accakeek creek at Brooke's mill. Bending its course towards the west and crgssing Potomac creek a litUe above the church, it pursues an irregular line coinciding with the western margin of the Eocene, before described, passing near Gray's mill on Little Fall run, and extending in a southeasterly direction to a point on the Rappahannock, nearly opposite the mouth of 8now creek. On the southern side of the river it is resumed near the mouth of Massaponax, and thence continuing in a line a little east of the stream, crosses Long branch a short distance above its mouth, and then bending round towards the west, marks the southern terminsr tion of the exposures of the upper secondary strata, thus far met with in this portion of the belt.

Proceedifig now to the western bonndarj of this northern area of the upper secondary, we find it extending from a point a litUe inland at Mount Vernon, in a direction nearly coinciding with that of the road marked on the map as passing through Colehesier or Oeeoquan in general, however, ranning somewhat nearer the river. Crossing Neabsco below the main road, it soon after bends west- wardly across the road, and continues west of it and nearlyparallel until it approaches the Valley of Quantico at Dunries, Here the floor of Primary is laid bare over a considerable space, owing to the local denudation which has formed the valley of the creek ; and the boundary line is made to sweep around in a course towards the east ; but soon turning again westwards, on the south side of Quan- tico, it continues in that direction for about two miles, when sud- denly turning to the south, it strikes across the Ghopawamsic, and intersects Acqnia creek near the mouth of Beaver dam ; thence continuing a little west of south, it passes about a mile and a half west of Stafford courthouse, and then by a still more westwardly bend, strikes Potomac creek about a mile above Wallace's mill ; from this point, it continues in a line east of south, crossing the Bappahannock about a mile west of Falmouth thence curving west- wards, so as to intersect the turnpike leading to Orange courthouse, at a point about three miles from Frederiekslnirg, crossing Hazel run still further to the west, and then striking across to the Massa- ponaz river, where it unites with the eastern boundary line previ- ously traced.

The boundaries of the southern tract of the Upper Secondary Rtrata are less distinctly marked than those of the area just de- scribed. For although extensive exposures of the rocks occur on the North Anna, Little, and South Anna rivers, and in numerous inland situations, the crumbling condition of the strata towards the margin, causes them so closely to resemble the loose sand and gravel which forms the usual covering of the Primary in this part of the state, as often to make it impossible to distinguish between them.

Instead, therefore, of attempting a detailed description of the outline of this tract, I shall content myself with indicating its form and dimensions by reference to a few well ascertained points. Its southern margin, passing nearly an eastward direction, lies about half a mile southward of the road leading from OoodalVs across the heads of Stag and Falling creeks to Hanover courthouse. Where crossed by this road, the tract has a width embraced between a point a little west of Stag creek, and another point near Mr, Win- 9torC$ about four miles west of Hanover courthouse, comprising a distance of about eight miles. North of this, where intersected by the South Anna river, it extends from a little above the mouth of Buck creek to within a short distance of the South Anna bridge, as laid down on the map. Still further north it expands eastwardly so as to occupy the bend of the North Anna, below the mouth of Lit- tie river ; thence its eastern margin, prolonged in a due north direc- tion, passes between the river and Concord meeting house. Its

western margin crosses New Fonnd river below tbe month of Beaver creek, strikes tbe road on whicb New Fork cbnrcb is sitn- ated, half a mile east of the cbnrcb, whence, intersecting little river below New Market bridge and North Anna, near the month of Long creek, it is indistinctly traceable to the neigbbonrbood of Obesterfield depot on the rail-road, north of which position, no un- equivocal ezposares of tbe upper secondary strata have yet been met with, until we approach the southern extremity of tbe northern tract at the Massaponax river.

South of the tract above described, tbe upper secondary strata are not again met with until we reach the valley of Sbockoe creek, near and within the city of Bichmond, where they form thin and very variable beds of a coarse conglomerate and sandstone, in alter- nate layers, interposed between the primary rocks, occasionally ex- posed in the valley of tbe creek, and tbe Tertiary beds of which tbe adjacent bills are chiefly made up. Under the same characters, these strata shew themselves along tbe base of the river bank at Rocketts, and at various points below, to within a short distance of Deep Hole, at tbe eastern extremity of tbe island called Farras Isl- and, where tbe Eocene strata are met with at the water level.

East of this, as was shewn in my last year's report, no deposits lower or of older date than tbe Tertiary are met with on the James river.

On tbe Appomattox, the upper secondary strata commencing at Bull Hill, a little below Broadway, where they are well exposed in the form of massive sandstones and conglomerates, and shewing themselves at Rocky Point, and for some distance along the river, above the month of Cobb's creek, under the same characters, and in much greater thickness, are thence traceable, at intervals, up to Petersburg, presenting, however, less extensive exposures and a much looser aggregation.

Of the characters of these strata, as presented at some of the in- teresting localities on and near the James and Appomattox rivers, I purpose treating under the next succeeding head.

With tbe exception of the cliff at Rocky Point, tbe strata in ques- tion attain but little elevation above tbe water level, where observed either on the James or Appomattox rivers, and on this account, be- ing deeply covered by diluvial matter, are rarely and very imper- fectly exposed in situations remote from the rivpr banks. Hence the extent to which they are spread out beneath the more superfi- cial materials, must remain matter of conjecture.

In the two tracts referred to previously, they are generally met with at, or very near, the surface, and when exposed on the banks of rivers and streams, often exhibit an aggregate thickness exceed- ing fifty feet.

Section III.

Characters and Contents of the Upper Secondary Strata.

These strata consist of sandstones, slates, shales, and conglom- erates, and as might be anticipated, display much variety as to col-

oar, teztare and solidity. Within the northern area, previously de- scribed, they are very generally characterized by containing a large proportion of felspathio earth, which, interposed between the sill- oeoQS grains forming nearly all the remaining material of the rock, imparts to it the open texture of a freestone, and renders it capa- ble of being easily wrought for architectoral purposes. Indeed in many oases, this material, by its great predominance in the mass, interfering with the partial adhesion of the siliceous matter, so im- pairs the aggregation of the stratum, as to cause it quickly to cram- Die into a loose sand.

In the composition of the variety here in view, the siliceous grains thus enclosed in the soft felspathio material, nre of well rounded forms, and in the beds usually resorted to for bnildlDg, of small and rather uniform size. But along with strata thus consti- tuted, layers and heavy beds of coarse conglomerates are not unfre- quently met with at the quarries and other exposures in the north- em tract, and have been observed at some points in the neighbour- hood of the North and South Anna rivers. In neither tract, how- ever, do they constitute a large part of the mass of the formation.

The presence of these coarse materials in predominant propor- tion, appears to be confined to the neighbourhood of the James and Appomattox rivers, where it is conspicuously displayed at nearly every exposure.

The liner variety of the felspathio sandstone, where of uniform texture, free from specks of ferrnginous matter and exempt from an excess of the felspathio eari;h, possesses many valuable qualities as a building material, combining sufficient strength for most archi- tectural purposes, a fair degree of durability under exposure to the weather, a pleasing light brownish grey colour, and a texture well adapted for the ordinary operations of the mason's chisel, or even for ornamental sculpture. While in the capacity of sustaining great weights without being crushed, it is no doubt inferior to some other varieties of building rook employed in this country, it is well adapted by its other qualities for numerous applications, in which the incumbent load is not excessive, and where a wrought or orna- mental surface is required. These important advantages have been so well appreciated, as to have brought it into extensive use in the construction of the public edifices in Washington, and have in this way for a series of years given active employment to numerous quarries in the neighbourho of Acquia creek, and on the Rappa- hannock river. Of these, the most extensive are the quarries of Menn, Stone, Oallakom, Toumon, Beard, and Adie situated near the head of Austins run — those of Meaars, Wallace, Brooke, and Ed- ininUm, aoiuing Acquia creek, and those of Measrs. Fitzhugh and Taliaferro, on the Rappahannock river.

At all these localities, the thickness of the strata exposed is very considerable, varying from 20 to 60, or more feet, and as might be expected, presenting among the different beds of rocks marked vari- eties in texture and composition.

At the extensive quarry of Mr, Oallahom the rock is for the

most part a nearly white sandstone, devoid of feimginoas staina, presentiDg the appearance of a bed of agglutinated sand, without distinct layers, and lying nearly in a horizontal position, and pos- sessing a remarkably uniform texture, and being free from join to, it is readily loosened from the quarry by wedges in blocks of any re- quired size. A few layers of coarse conglomerate are seen extend- ing through the mass. At the quarry of Messrs, Beard and Adie the rock is a light coloured sandstone, but appears in distinct layers from 2 to 4 or more feet in thickness. Similar characters prevail at the other quarries on Austins run and Acquia creek.

The quarries opened for the construction of the railroad bridge over Potomac creek, about half a mile above the church, present very extensive exposures of the sandstone. It is here seen on both sides of tlie creek, forming cliffs of from 60 to 70 feet in height, and has been applied both in forming the piers and the abutments of the bridge, that used for the latter purpose being quite coarse, and de> rived from the upper layers.

At the quarries of Mr. Francis Taliqferro, situated on the Rap- pahannock river, about half a mile above the mouth of Massaponax, the sandstone extends from 20 to 25 feet above the water. It is in general a compact, well cemented rock, varying from a nearly white to a light brownish grey colour. The latter tint is generally devel- oped after exposure to the air, and is obviously due to the decom- position of the embedded particles of iron pyrites present in the strata of this as well as other localities.

It may be well to remark, that the ferruginous stains, so com- monly presenting themselves upon the weathered surfaces of the rocks of which I am treating, though iniurious to the beauty of the stone, are not likely to impair its durability, unless the decomposing pyrites be present in very large amount, and in ordinary cases, the blemish may be readily corrected by the application of a coat of paint

Associated with the sandstones above described, there occur in the northern tract various strata of shale and slate and sandstone, presenting at certain localities a number of interesting vegetable impressions and other remains. Of these it is not my purpose to n>eak in detail at the present time. It will be sufScient to remark, that the characters of these remains are such as to throw important light upon the geological history of the strata with which they are associated, and will therefore entitle them to a detailed considera- tion, when I shall be called upon to illustrate the interesting scien- tific relations of the upper secondary rocks. I may also add that the lignite and charcoal derived from the decomposition of these vegetable substances, and so abundantly displayed in many locali- ties, though seemingly in favour of the existence of beds of coal in tliis formation, have no essential connection with extensive deposits of this material, and that in view of the age and general character of these upper secondary rocks, as well as the extent to which they have been explored, there is no reason for believing that they contain any seam or bed of coal worthy of economical notice.

AdyertdzKg now to the strata as presented in the soutbem tract, I would remark that while in many respects analogous to tiiose above described, they display modifications of colour, texture and composition entitling them to a separate notice. Instead of the whitish, open-grained freestone, so predominant in the northern tract, we here meet with bluish grey sandstones, composed of fine particles of sand blended with mipure felspathic clay and some scales of Mica, others of a similar texture but of a brownish tinge ; coarser sandstones in which white felspathic earth and coarse oli- ceons grains are interspersed in these finer materials; brown and olive coloured slaty sandstones and argillaceous tes, together with other varieties bearing the same general character, and along with these at some localities beds of felspathic freestone similar to those of the northern tract. As a general rule, the rocks in question compared with those of the district to the north, are of a darker hue, contain more Mica, and are of a finer grain and softer texture. In most exposures they are seen in a crumbling state when acted on by the weather, and are in general possessed of little strength or durability. Localities, however, are not wanting capable of afford- ing rock of a better quality ; and to these resort has been had in the vicinity of TaylornilU and elsewhere, for the uses of the rail- road.

Lignite and thin seams of impure bituminous coal are of frequent occurrence in these rocks, especially towards the southern extremity of the tract. In the bluish and brownish grey soft sandstones met with so generally in the neighbourhood of Taylorgville, on the North Anna and Little rivers, stems and other vegetable fragments are often found, presenting the condition either of bituminous coal or charcoal; thin layers of slaty lignite are not nnfrequently exposed in the same rocks, and have led to the fallacious idea of the presence of important beds of coal in their vicinity. Towards the southern margin, the sandstones in many places are largely intermingled with dark coloured micaceous slates and bituminous shales, among which are found thin seams of an impure bituminous coal. Ex- posures of this kind occur at several places towards the western side of the tract, on Beach and Stag creeks, presenting the following appearances :

On Beach creek, at Mr, Lowerre'a a grey siliceous sandstone oc- curs, associated with much dark micaceous slate and black glazed bituminous shale, a coarse couglomeritic sandstone, and brownish soft shales, enclosing a very thin seam of bituminous coal.

On the Poor house tract, situated on Stag creek, we find grey felspathic sandstone of fine grain and rather compact texture, asso- ciated with brownish and black bituminous shales. The latter, at the spot which has been explored for coal, contains two small lay- ers of that substance, rather irregularly disposed in the shale, the entire bed, shale and coal included, being about five feet in thick- ness.

Further to the east the bituminous shales are rarely met with, the rocks consisting of coare congloroeritio sandstone, reddish

brown mioaceoos Bhales, and loose grained felapathic sandstone, gen- erally Brined with oxide of iron. At one or two points in tills vi- cinity small patches of the Tertiary strata are met with in the form of a light greenish micaceous clay or loam, impregnated with salphnr and sulphates, and containing casts of univalye and bivalve shellSf but without any remains of shelly matter. The dips of the strata above described as disclosed in the southwestern comer of the tract vary from northeast to southeast, and even to northwest, and are often as high an forty-five degrees, in this respect differing from the upper secondary strata in the more northern and eastern portions of the belt It may, indeed, be observed as a general fact that the deviation from a horizontal position is greater in the sonth- em than the northern tract, and that it is seen to increase as we proceed south west wardly in the latter.

The proximity of the district on Beach and Stag creeks, to the ooal basin of the Deep Run and Springfield pits, south of Ohicka- hominy river, and the general resemblance of its rocks to those of the coal measures, added to the fact of the actual discovery of coal in the localities just described, have led to the supposition that the true coal rocks are extended northwards of the Cliickahominy, and will there also be found to inclade a valuable seam or seams of coaL Careful observations, however, have clearly shewn that the meas- ures of the basin south of the river, nowhere extend over to its northern bank, but are walled in by a barrier of primary rocks, which have been traced entirely around their northern termination, and that the tract between this and the southern margin of the upper secondary, traversed by the road leading to Ground Squirrel bridfre on the South Anna, is entirely primary.

There is, however, reason to believe that the rooks in the south- west comer of this upper secondary tract are more nearly allied in age to those of the trae coal basins lying to the south, than the strata generally to which I have provisionally given the name of upper secondary, and that occupying somewhat an intermediate place in the series, they might be expected to present a more close resemblance to the coal measures both in character and contents than the other strata of either the north or south upper secondary tracts.

As essentially connected with this subject, it is important to re- mark, that after much investigation as regards the true geological character of the coal basins of Benrico Chesterfield &c., I have become satisfied that instead of being older, they are of more recent production than the carboniferous strata of our great western coal region and most of the European coal measures, and that the era of their formation is not widely removed from that of our upper sec- ondary strata. Of the various data which have served to iUustrato this very perplexing enquiry, it would be inappropriate to entor into an account m this place; suffice it to say, that notwithstanding the rareness of well preserved fossils in these coal fields, I have at length been enabled to procure such as are adapted to shed impor- tant light upon the interesting question above aJluded to, and con-

nected with other considerations, to lead to conclnsions at once onri- oas and satisfactory.

Of the upper secondary strata, as exposed on the James and Appomattox rivers :

As formerly remarked, the exposures of these heds in the dis- trict here referred to, are almost exclnsively confined to the ahmpt river banks, and to certain points adjoining the primary in the deep ravines below Biehmand. Some observations upon the general com- position and character of these strata, along with a description of one or two interesting localities, will suffice to convey a jnst con- ception of their peculiarities, and will render further details unne- cessary.

The loose aggregation and coarse materials of these beds, give them so great a resemblance to the common diluvium of sand and gravel, generally forming the surface strata in this part of the state as to render careful observation necessary in order to distinguish between them, and even the closest inspection, in some cases, will scarcely suffice for this purpose. This obscnrity, however, does not apply to localities in which the Tertiary beds are seen resting upon them, as in such cfltes the subjacent position of the sandstone or conglomerate determines its true geological character, the diluvial Band or gravel having its place above the Tertiary.

The difficulty of making this distinction is chiefly felt in relation to some of the exposures on the rivers, where the Tertiary having been removed by denudation from above the upper secondary beds, has been replaced by the mass of diluvial sand and gravel, deposited upon the broken surface of the secondary, often no doubt with much intermixture of the materials of the two ; but even in these cases a marked difference may be noticed in their composition, es- pecially in the fact of the comparatively large amouut of white fel- spathio earth blended with the coarser matter of the upper second- ary. Indeed, at most localities, however large may be the pebbles embedded in some of the layers, the intervening matter will be found to possess the character of a soft felspathic sandstone, and some portions of the mass will display this character through- out.

The pebbles thus embedded in the finer material of these beds, sometimes in layers of many feet in thickness, but oftener in narrow courses, are frequently of great size, measuring even as much as eight or ten inches in diameter. They are of very various origin ; some being from the primary region, and consisting of Quartz, Gneiss and primary slates, while others are from the formations farther west, and especiaJly that lying on the valley side of the Blue Ridge, and which I have designated as the first of the series of rocks of our great Appalachian system. These fragments of formation I., remarkable for their bright white colour and their great magnitude, serve to distinguish the mass in which they occur from the overly- ing diluvium, in which nothing analogous has as yet been discovered. Forming, thus, part of what may be considered as ancient diluvium, belonging to the secondary era, they point to the extensive agency of

44S

the currents by wliioh the heterogeneous materials of these apper secondary strata were swept together.

At Rocketts, immediately below Eichfn&nd may be seen beds of the soft felspathic sandstone, with layers of coarse gravel and peb- bles lying near the base of the bank, and above these, beds of clay, sand and gravel, referrible to the common diluviam. Similar ap- pearances present themselves at various points lower down the river, and are well observed on the land opposite Farrars island. Here, adjoining the wood wharf, near Osbornes ferry, the river bank rising abruptly, presents a good exposure of the soft felspathic sandstone and gravel for a height of about 24 feet. For some feet below the floor of the wharf, and as low down as the water level at medium height, the bank consists of brownish soft sandstone, en- closing a few pebbles. Above this is a nearly white felspathic sand, partially cemented, with a few layers of white nebbles; and still higher, a heavy bed of similar pebbles, packed in layers of the fel- spathic sand. Strata of a similar character, enclosing pebbles of huge dimensions, together with rounded masses of clay, occur at the ferry.

In the vicinity of Petersburg similar materials are exposed along the base, and for some height in the hill forming the northern bound- ary of the river bottom, and may be seen at the cuttings for the rail-road and other roads in that direction ; a thin layer of Tertiary clay here separates them from the upper diluvium. Southeast of the Appomattox, the surface is a table land raised between 80 and 40 feet above the water. This extends down the Appomattox to Bull Hill, which, commencing a little below Broadway, forms the river bank, thence for some distance towards Oity Point. The strata lying beneath this plain are of the same character as those just described, and are doubtless the upper secondary sandstone overlaid to some extent by modern diluvium. East of this an upper level rises rather abruptly, marking the western margin of the great Tertiary plain, which thence extends eastwards towards the sea.

The steep bank exposed along Bull Hill, discloses the felspnthic sand and pebbles for some height, capped by ferruginous clay and sand, while on Bull Hill creek, which enters the river at the eastern extremity of the hill, we find sandstone and conglomerate of very firm texture in heavy beds, rising above the water from 12 to 15 feet. Rock of a like description is also exposed in the bank a little above Broadway.

Bat by far the most interesting exposure of these strata to be met with on the Appomattox, are those of Rock Point and its vi- cinity, on the west side of the river and below Cobb's. An abrupt bank here shews itself about thirty feet in height, of which nearly the whole is well exposed, consisting of the felspathic sandstone and conglomerate in huge beds, lying nearly . horizontally, and divided to a great depth by vertical joints. Most of this rock is thickly interspersed with pebbles from one to two inohea in diameter, the intervening material consisting of felspathic sand, and the whole

being quite oompaot and bard. Namerons large masses tbat have tumbled from the clif and now lie at tbe waters edge or in the water, strikingly attest the durability of this variety of rock.

Other layers are crnmbly and fall into sand. Hnge pebbles lie embedded in the finer material, some of them not less than 12 inches in diameter, beantif ally white and fine grained, and evidentiy de- rived from formation I, of the Appalachian rocks.

The lower extremity of this olifij and the banks, of Bull Hill creek, terminate the exposures of the upper secondary on the Ap- pomattox. The plain between the Appomattox and the James river, towards the junction of the two, presents occasional expos- ures of the Tertiary, and beds of this formation begin to shew themselves as we trace the Appomattox shore towards (Htff Point, We may therefore approximate to the common boundary of this and the secondary sandstones, by a line drawn from the mouth of Bull Dill creek to the neighbourhood of Deep Bottom on the James river.

Section IV.

Infusorial Stratum and Associated Tertiary Beds in the Vicinity of

Richmond,

Having adverted to the general character of what are called In- fusorial remains under a former head, I shall confine myself in what follows to a brief description of the more striking peculiarities of our Infusorial stratum, and thence proceed to a sketch of the ge- ology of the district in and adjoining Richmond in which it has been my good fortune to find it developed.

The material in question, composing a thick stratum lying be- tween beds of sand and clay, is more or less mingled with them, particularly in the vicinity of its bounding surfaces. But through- out most of its thickness, it presents a very fine texture, admitting of being bruised by the fingers into an most impalpable powder, and singularly free from gritty particles. Its colour in the present specimens, is a very light grey or white, but the fragments into which it spontaneously divides at the exposed surface of the stratum, often present externally a slightly ochreous tinge. It is decidedly, though sometimes indistinctly laminated, the planes of the thin flakes or sheets being horizontal. When moistened, it displays con- siderable tenacity, and hence has hitherto been regarded as a fine cli or fullers earth.

Of all its peculiarities, however, capable of being readily discov- ered, ita great lightness is the most extraordinary and characteris- tic. When quite free from moisture, a pure specimen has a specific gravity of only 0.334, that is to say, only one third the weiglit of water, bulk for bulk.

In adverting to the curious and astonishing fact of its being composed almost entirely of the shells and other appendages of for- mer races of animalculss, it was also mentioned that unlike the mi- croscopic remains composing the chief mass of chalk or the larger

fossils of our marl beds, these ininQte relics consist entirely of sUi" ceovs instead of oalcareoas matter. For this reason it is, that the Leaf Tripoli, or Polir Scheifer of Bohemia as well as other analogous Infusorial products, have so long been found valuable in giving a polish to metalJic surfaces. Our Infusorial matter, when properly selected, is capable of being employed for this purpose with no less advante, and from the trials I have made, I feel assured that when exempt from, grit, it may be very usefully substituted for the finer varieties of the Tripoli or rotten stone of the shops.

Of the forms of these microscopic remains no just conception can be conveyed to the general reader without the aid of drawings representing them in a greatly enlarged scale. I may however re- mark, that while these forms are very numerous, and refer them- selves to many distinct species of minerals, they may in a popular way be described as for the most part referrible to two classes.

One of these is an oblong cyhnder, rounded or knobbed at the extremities, and conttuning within a multitude of rings arranged parallel to each other, from end to end, and forming, as it were, the internal skeleton of the animal. The other is a round disc, more or less convex, and sometimes nearly spherical, often perforated through the centre, and presenting over its surface an exquisite net work of inconceivably minute belts.

Of the minuteness of these objects, some idea may be formed from the following statements :

The cylindrical bodies of the medium size are from yt-th to but many fall greatly short of these dimensions.

The rings, which are found separate in great numbers, are usu-

The circular discs and convex bodies, reticulated with cells, vary from -Ajfth to in diameter. In each of these are hundreds, and even thousands of beautifully wrought cells. The predominance of these flattened forms appears to be the cause of the laminated tex- ture already mentioned as exhibited by the Infusorial earth. It is obvious from these facts, that the number of such fossils comprised in each cubic inch of the material, can only be reckoned in millions or hundreds of millions, and that a bushel measure would contain a number of these skeletons and shells of former races of animalcu- liB, far exceeding the entire population of the globe. Of the impor- tant geological agencies of the living races to which these remains belonged, we need no more striking illustration than will be fur- nished in the foUowing sketch of the extent and relations of the In- fusorial stratum. And I may add that while, as formerly remarked, this stratum at Richmond and on the Rappahannock, fumislies the only instance in which these remains have been found in the United States, forming portions of any formations but those of the present epoch, its thickness and the extent over which it is spread x)ut, en- title it to rank with the most interesting beds of siliceous Infusorial remains yet discovered in Europe,

The valley of Shockoe creek, lying between Shockoe bill and

Oharch hill, affords namerons favourable opportunities of obserWng the position of the Infusorial bed, and the strata with which it is associated by explorations along the sides of the bounding hills and the deep ravines by which, in many places, they are abruptly trenched.

The middle of this valley is occupied by coarse gravel, rarely discovering any materials in situ. Beside the stream, a little to the left of the crossing of Shockoe hill Main street, as continued over towards Ghnrch hill, a patch of primary is displayed, consisting of Gneiss containing some Hornblende, and intersected by several veins of Felspar.

At the base of Shockoe hiU, a short distance up the principal ravines, the felspathio sandstones and conglomerates may be seen, forming the channels of the little rivulets flowing in these hollows, and rising, when best exposed, to a height of about five feet above the bittom of the ravine. Of course, near the outlet of the hol- low, the heavy diluvium from the upper part of the hill conceals or replaces every thing else, and neither the felspathio sandstone nor overlying beds, can be seen, until we enter some depth into the ravine. We may thence trace it upwards, until, in consequence of the slope of the surface, we reach a higher level than toe npper limit of this rock, when it disappears from view. This stratum con- sists of the felspathio sand in irregular layers, loosely cementing pebbles of various dimensions from 1 to 4 or 5 inches, some of which belong to formation I. An analogous material is still more extensively exposed in the mill race at the mill, higher up the creek, and composes the low knoll on which the mill is placed. Here we find the felspathio sandstone in general much stain&d with ferruginous matter, overlaid by a bed of very coarse oon- glomerate of an ochreous stain and unusual hardness. Similar sandtsones and conglomerates are displayed at various points along the margin of the stream, for a thickness of several feet above its surface.

Resting upon this sandstone and conglomerate, we meet with beds of sand and sandy clay of a dark greenish and lead colour, and of a light grey, mottled with yellow, containing Sharks* teeth and Eocene Oarditas, Tnrritellas, Crassatellas, &c., in the form of casts, together with vague vegetable remains in a carbonized condition. The contact of these Eocene strata with the underlying sandstone, 18 weU displayed at the following points :

1st. The ravine adjoining Shockoe hill Main street, where the culvert opens.

2d. That beading immediately in the rear of the Monumental church.

8d. That between Col. Ambler's hill and French Garden, by far the most prolonged of the ravines on this side of the valley.

4th. That next above French Garden and between it and the Poor house. Above the point last named, the sandstone is buried out of view, and the lowest stratum seen belongs to the Eocene.

Above these Eocene beds occurs the enormous deposit of Micro-

scopio remains, which I have called the Ti\fuMarial stratum having the bright grey or nearly white tint, and the astonishing lightness before described.

This stratum shews itself at nearly the same level on the hill sides, and in the ravines on both sides of the valley of Shockoe creek, and may be traced on the Shockoe hill side of the valley, without iuterrnption, as far as the crossing of the Hanover road towards the head of the valley and near Turner's mill. From a point on the slope of Church hill, a little beyond Butchertown, commanding a view of the hills and ravines from the Poor house down, it is easy to trace the broad belt of this deposite by its surface being com- paratively deprived of herbage, and presenting a white and barren aspect

The thickness of the stratum varies at different points from 12 to 25 feet, the most striking exposures being those met with in the ravine behind the Monumental church, and that between Col. Am- blers and French Garden.

The same, or a very similar order is observed, in the exposures visible on the opposite side of the valley along the slope of Church hill. At the bottom of the ravines, which are here comparatively shallow, we see the upper portions of the Eocene, and over this the Infusory stratum, shewing itself plainly and of great thickness, at the following points :

1st. Just back of Butchertown, on the two roads that extend up the hill.

2d. At the foot of the abrupt bare bank which has been cut into north of the Main street, on Church hill, and thence south nearly to the next street.

Indeed, along the slope of Church hiU, as on the other side of the valley, this stratum may be found in all the savines and cuttings at the proper leveL

Above the Infusorial stratum are lead-coloured and ochreous sands and clays, sometimes nearly resembling it in colour, but read- ily distinguished by their greater heaviness. These, which belong to the Meiooene division of the Tertiary, are remarkable for con- taining, near and for some distance above the Infusorial stratum, numerous vegetable markings of a vague description, as well as many well defined impressions of leaves and stems ; and towards the top, impressions of Scallop shells (Pecten) and other Meiocene fossils. Among the numerous points at which these strata are ex- posed, the following may be mentioned as interesting and easy of access:

1st. On Governor street, as yon descend Main street, where the impressions of shells are very numerous.

2d. The steep bank opposite the Synagogue. Here the clays near the base, abound in vegetable impressions, among which are admirably defined leaves. Towards the top, the more sandy ma- terial contains impressions of Pectens.

8d. On Church hill, back of Mr. Van-Lews garden, and the bare bank exposed along the valley side of the hill behind Mr. Grean&r's

dwelling. The base of this bank is on a level with the top of the Infasorial bed.

The minute details which have now been presented in relation to the Infusorial bed and its associates, though uuimportant to the general reader, are here given, that those residing near maj be en- abled to gratify their curiosity by observing for themselves the ex- tent and relations of this canons deposit. I will now conclude the subject with the following :

sBcnoir OF tbx btbata disclosed m the niiNciPAL raviks on the west

BIDE or THE VAUJET OV 8BO0KOB CHEEK.

1st. Felspatliic sandstone, upper secondary, 4 feet.

2d. Dark olive and bluish stratum, tenaceous while moist, but becoming mealy and of a greyish tint when dry, and in that condition shewing an efflorescence of gypsum upon the surface. Impressions of Cardita, &c. — Eocene, . 4

8d. Lighter coloured bed, with yellowish blotches, and streaks very friable even when moist, being more sandy than the preceding. A few impressions. — Eockne, 8

4th. Brownish black, containing a few prints of fossils and a large amount of carbonized vegetable matter, to which the colour of the stratum is owing, 5 "

5th. Lead coloured heavy day, with a greenish tinge.. 8

6th. Infusorial Stratum. 20 "

7th. Greenish brown and lead coloured clays, with ve- getable impressions. — Meiocens, 6 "

8th. More sandy stratum of mottled grey and yellowish brown, vegetable impressions and prints of Pectens. — Meiogene, 14 "

Above the last named bed are others belonng also to the Heio- eene, but they are too imperfectly exposed for accurate obser- vation. On top of these, and forming the highest of the deposits in this vicinity, are the beds of diluvium, composed of sand and gravel.

Chapteu Iv.

Horthern District Between The Blue Ridoe And Head Of

Tide,

Section I.

Flan of Exploration — General Geology,

A general examination having been made of a large portion of this region in former seasons, as indicated in my last and some of the preceding reports, onr operations were directed almost exclu- sively to the investigation of detailed sections, and to the minute tracing of the several formations and more important bands of rock met with in the district, with a view to their delineation on the map, associating with these labours the careful exploration of

all localities where materials of economical or of cuions interest might be found, as well as the collection of ample suites of speci- mens for geological illustration and chemical analysis. In the exe- cution of these objects, our progress, though in some degree arrest- ed bj the lamented event referred to in the beginning of this re- port, has been sufficiently great to enable me in conformity with the plan adopted last year, to present a systematic, though brief ac- count of the more interesting features of the district. In doing this, however, I wish it to be borne in mind, that in many parts of the district our researches are far from having been completed ; and that consequently, in the descriptive sketch now about to be pre- sented, important areas as well as interesting individual localities, will require to be omitted, while at the same time the illustrations, so far as attempted, will aim at as much accuracy as can be at- tained in the compendious form to which they are limited, and without the accompaniments of a map and sections.

Entering upon our researches witn a view to minute detail, the following principal sections were proposed for examination at the opening of the season, being designed as the frame work for inter- vening observations :

1st. Along James river from Columbia to Hihmtmdy connect- ing at the former point with a section constructed the preceding year, thence to the Blue Ridge,

2d. From Stoift Run Gap by StanardsviUe BarbaumiUe and LouiM courthouse to Hanover courthouse.

3d. From ITiorntons Oap by Fairfax (Gulpeper courthouse,) Stevenshurgy Oermanna Ford to Fredericksburg.

4th. From Ashbys Gap by Paris, Aldie Fairfax courthouse to Alexandria,

6th. From Chester Gap through Warrenton to Duffriet,

6tli. Along or near the Potomac river from Harpers Ferry to Georgetown,

Of these principal sections, two have been entirely, and one nearly completed, and each of the others more or less advanced, at the same time that numerous shorter intervening sections have been explored either partially or to completion, and a satisfactory progress made in the longitudinal tracing of the more important belts of rock.

In these investigations, as usual, particular attention has been directed to such deposites as are or promise to be of economical value, and in this view, the various patches or interrupted ranges of limestone, as well as the iron ores, slates and building rocks gener- ally met with in the tracts observed, have been carefully examined.

After what has already been stated, it is scarcely necessary to repeat, that although in portions of the district under consideration our enquiries have been quite as extensive and minute as could be desired, much additional observation is demanded for the comple- tion of the sections yet in an unfinished state, as well as for bring- ing to a close the various local researches thus far omitted, or but in part accomplished. These will, it is hoped, form a portion of

the daties of the coming season, when as I have previonalj stated, it may be confidently expected that oar field labours in this as in other parts of the state will be brought to a satisfactorj conclu- sion.

The general geological features of the region now in view are closely correspondent to those of the district south of the James river, of part of which a somewhat detailed account was presented in the repent of last year, and I may, therefore, refer to the descrip- tions then given in connection with the glossary to be appended to the present report, for a full explanation of the composition and more striking characters of the rocks and minereds of which I am about to present a few brief details.

Throughout the greater part of this region the rocks are of Pbi- MABT and Metamobpbio characters, consisting chiefly of Gneiss, Mica slate, Talcose slate, Epidotic rock, Hornblende slate. Argilla- ceous slate. Quartz rock, Quartz slate or Quartzite, and Pseudo Gneiss or Gneissoid sandstone, with occasional beds of Granite and 8ienite. With these are associated numerous beds and dykes of Trap, and over a large space towards the centre of the district, are spreioid out the nearly horizontal strata of sandstones, shales and conglomerates, corresponding to the belt referred to in my last yearns report nnder the name of the Middle Seoondabt Fobmatiox. Towards the eastern margin of the region occur the f elspathic sand- stones and associated beds of the upper secondary strata, and the interesting formations of the Deep Run and Tuckahoe coal basins, of the former of which some account has already been given in the present report.

In the following brief illustrations of the geology of this region, I shall treat,

lirst, of the primary and metamorphio rocks, indoding the beds of limestone associated with them at various points; and, eeondly of the middle secondary tract.

Section IT.

Of the Primary and Metamorphie Eoch intlttding the Beds of Limestone auociated with them at Various Points,

Referring, as already mentioned, to my last yearns report, and the glossary appended to the present, for an account of the compo- sition of the several classes of rocks of which I am about to speak, I propose treating of them in the order of their relative extent, and will therefore begin with

Gneiss. — Rocks of this description occupy a large portion of the district. Besides being met with in intermediate lines, they are largely developed in two extensive tracts, one of which stretches in the form of a belt from the eastern flank of the Blue Ridge to the neighbourhood of the Southwest mountain in Albemarle county, gradually contracting in width in its prolongation towards the north- east, and finally near the Potomac, compressed between the eastern

flank of Short hill and a line some distance west of the Eittoctin monntain, the other forming an irregular triangolar area, having its apex a little west of IhredrieMtirgj its eastern side in a nearly meridianal direction, coinciding with the eastern limit of the pri- mary rocks along the head of tide, and its western side parallel to the geuerid coarse of the Southwest mountain, and terminating a few miles west of Columbia,

The Gneiss of the westernmost of these tracts is in general of a darker colour and coarser texture than that of the other, especiallj towards the eastern margin of the latter. It also presents much greater variety in its composition. In most localities, with com* paratively littie Mica, it contains more or less Talc, occasionally Chlorite, and in a great number of cases, Hornblende and iron Pyrites, the latter fuding its disintegration, and along with the Horn- blende, imparting more or less of a reddish tint to the soil into which it is resolved. Near the eastern base of the Blue Ridge, as for ex- ample in approaching Swift run, Thornton's or Ashby's gaps, a va- riety is met with, sometimes extensively exposed, containing a blu- ish somewhat milky Quartz, and in the same tract, belts or ranges of Granite or Granitic Gneiss occur, into which the adjoining rocks seem insensibly to graduate. In this belt also occur bands of Mi- caceous and Taloose slates, sometimes of such breadth as greatly to encroach upon the area of the Gneiss, but in general occupying only a small part of its entire width.

These, as might be expected, are not very distinctly defined, but

f)ass into the Gneiss by imperceptible degrees. With a very few ocal exceptions, the Gneiss and associated slates of the belt in ques- tion have a strike nearly to N£. and a steep dip towards S£.

The Gneiss rocks of the eastern tract likewise display several varieties. Along the eastern margin, and for some miles westward, the variety chiefly met with is a grey rock, conusting of Quartz, Felspar, and black Mica, with occasional spangles of white Mica, and scattered grains of Hornblende. It is of an even texture, read- ily separating in large slabs and blocks, suited for columns and other purposes. Being easily wrought to a smooth surface, and to any required shape, and possessing, when properly selected, as great durability and strength as is necessary, it is deservedly looked upon as a material of great value in architecture. Of this variety, innu- merable exposures are presented on both sides of the James river in and above Richmond and on the Appomattox in and above Peterthurgy and a similar rock, though in much less extent, is seen on the Rappahannock above FredeTiehtHmrg,

Along the James river canal above Richmond it is displayed al- most without interruption for a distance of many miles, presenting various moditications of texture and composition, but in the main preserving the general characters above described. Though subdi- vided by joints cleaving the strata to great depths in planes of great steepness, and of which the principal one dips towards the south- east, the bedding or stratification of the rock is not in general steeply inclined, but undulating and with a prevailing dip towards

the same point A similar remark is applicable to the Gneiss on and near the Appomattox in the vioinitj of Petersburg, as may readily be verified by reference to the exposures near the mills within the town, and on the opposite side of the river, as well as the qaarries near and above Battersea.

An intimate blending of the Quartz and Felspar, and a large pre- dominance of the former, are important characteristics of the most ▼alnnble beds of this rock, and should be borne in mind where a selection is to be made for architectural purposes. In some of the layers, the Felspar is met with in great excess, imparting to the stone a tendency to crumble by exposure, in consequence of the converMon of this ingredient into a white powder (Porcelain earth,) and the loosening of the grains of Quartz. To distinish between the Felspar and Quartz, it will be recollected that while the former is of a anil white or pinkish hue, and opaque, the latter is trans- parent; and that while the former, after some exposure, presents more or less of a mealy surface, the latter retains its clearness and lustre unchanged.

At various localities both on the James and Appomattox rivers, extensive beds of this Gneiss occur, of so fine and even a grain, as to admit of delicate sculpture, and of being wrought down to a smooth and almost polished surface. The pleasing light grey tint, and the undoubted strength and durability of this variety, give it a very high value as applied to the construction of steps, sills, monuments, and ornamental as well as substantial masonry in gener. I need scarcely add, that the exposures above referred to, present numer- ous very favourable positions for quarrying and for transporting the stone to the neighbouring cities, or to the seaboard, and that con- sidering its beauty, durability, facility of being wrought, and con- venience of position, it cannot fail to become an important item in tlie resources of the particular neighbourhoods in which it is found thus favourably situated.

Besides the occasional beds of coarser Gneiss, containing much pinkish Felspar in large crystals, and presenting, though stratified, the composition of a Syenite or Syenitic Gneiss, we find at nearly every quarry veins of Felspar traversing the beds in various direc- tions, and not unfrequentfy subdividing and mutually intersecting. These are usually of small dimensions, rarely exceeding two or three inches across. But besides these, we observe at many exposures, veins and dykes of Granite and Syenite penetrating the Gneiss, and in some instances in such extent as to present large protruding masses, or broad surfaces of the granitic and syenitic rocks above, as may be well seen at several points along the James river canal, and perhaps still more readily at the rugged exposures adjoining the mills on both sides of the Appomattox at Petersburg, In the latter locality, the bedding of the Gneiss is quite distinct, the dip varying from north a little to the east and to the west, the angle in general about fifteen degrees. Here the veins of Granite and Syenite pene- trating the mass in various directions, and often intersecting one another, by causing the very unequal weathering of the rook, have

So

given rise to its pecnliar mggedness of fonn. In this and the other localities, the granitic veins are at once detected by the large scales of silvery Mica, adhering to the surface, or embedded in the mass, and those of Syenite by the almost total absence of the black Mica nsaal in the Gneiss, and the large predominance of the Felspar over the remaining ingredient, the Quartz.

The rocks above referred to, forming the margin of the pri- mary on the east, after extending over a breadth of some miles, are seen to give place to other modifications of Gneiss. These differ from the preceding, in having generally a more slaty structure, and being much less uniform in aspect and composition. As a group they are also more felspathio, contain much more Hornblende, are less capable of resisting atmospheric agencies, and are consequent- ly found in a decomposed state, to a greater depth beneath the sur- tace. Belts of Hornblende slate occur, associated with them, and in many belts the Gneiss itself is so largely imbued with Horn- blende, that it forms the characteristic mineral of the rock. These Hornblende slates and Homblendio Gneiss rocks, being less easily decomposed than the felspathio rocks with which they are a&- Bociated, are frequently met with in the ravines, while the latter, though extensively indicated by the deep beds of white and ochre- ous felspathic clay, still retaining some traces of the previous rocky structure, are but rarely seen upon the surface. Beds and veins of Quartz are of not unfre(uent occurrence amongst these rocks, and beds of a coarse description of iron ore have been found in them at a few localities.

The dip of these rocks, although for the greater part of their extent towards the SE., presents in some sections repeated alterna- tions between that and a northwest direction, the angle in general being high.

At numerous places in the belts occupied by the highly fel- spathic Gneiss, the extensive decomposition they have suffered has given origin to beds of felspathic clay of great whiteness, including the unchanged particles of Quartz and leaves of Mica, originally united in the rock. This material is often of such purity as with proper preliminary treatment to form a valuable porcelain earth ; and there can be little doubt that when the manufacture of the finer varieties of pottery becomes established in Virginia the tracts in question will be capable of furnishing abundant supplies of this material of a quality adapted to be thus used.

Micaceous Taleose and Argillaceoui Slat€$.

Westward of the triangular district of Gneiss rocks Just alluded to we find a broad belt of more slaty rocks, which, according to the peculiar ingredient predominant for the time, are either of the Mi- caceous, Taleose or Argillaceous character.

This belt reaches nearly to the eastern flank of the Southwest mountain, in Fluvanna Albemarle and Orange counties ; and fur- ther north, though in port covered by the middle secondary rocks,

there widely expanded over the corresponding region, is still trace- able in considerable width east of that formation, through Fauquier. Prince William and Fairfax counties, as well as in narrow ana interrupted tracts along the eastern base of the Bull Run and Kit- toctin mountains.

As a general character these slaty strata, where adjoining the Gneiss tract, are more micaceous than farther west. Indeed the Mica slate is here seen alternating with the Gneiss over a consider- able width : nor indeed are the more central or even western por- tions of the tract exempt from occasional and sometimes extensive ranges of certain Tarieties of Gneiss.

Referring, however, merely to general features, the micaceous Of>mpo8ition, thus most strikingly exhibited towards the eastern margin of the slaty belt, is seen changing as we proceed west into one in which Talc is more or less blended with the Mica, and even in some cases entirely replaces it.

These Talco-micaceous slates and Talcose slates, extensively de- veloped in the western half of the slaty tract, include in some places beds of Ghloritic slate, of Steatitic slate or impure Soapstone and of Serpentine. But these associated rocks are rarely developed with great distinctness, and are only found over areas of small ex- tent. For the most part they present themselves near the centre of the belt. It is in this position also that occurs the irregular and , interrupted range of Ghloritic Gneiss and Micaceous slate, with Ghlorite, noticed in my last yearns report, as disclosed in Bucking- ham county, and which displays itself in the Green Spring tract in LouiM. It is here, as in Buckingham, associated with Uomblen- dio Gneiss, and presents some beds of a species of Sienite, contain- ing beautiful crystals of Epidote embeddea in pinkish Felspar.

Towards the Western margin of the belt, near the base of the Southwest mountain, as well as at several points where the slaty rook are left uncovered by the middle secondary in a similar posi- tion as regards the Bull Run and Kittoctin mountains, a larger ad- mixture of argillaceous matter to a great extent takes the place of the Mica and Talc, thus presenting us with Argillaceous slates, still, however, retaining in some degree their Micaceous and Talcose character.

These again include strata of a more arenaceous composition, composing gritty slates, sometimes approaching the character of a sandstone or conglomerate, and analogous to those described in my last year's report under the name of Gneissoid sandstone or Pseudo Gneiss ; and again, by a still more exclusively siliceous composi- tion, and a finer and more nearly crystalline texture, the same slaty rocks pass into Quartzite or Quartz slate.

Throughout the whole of tiiis belt of slaty rocks, veins and beds of Quartz are of very common occurrence, and in the Talcose and Micaceous slates especially, are frequently more or less auriferous. In fact this belt includes nearly every locality in the northern pri- mary district in which mines have been opened for extracting gold, or in which the metal has been found ; and it may be added, that

its prolongation soatb of James river embraces the gold district of that part of the state.

Associated with these slates, and near their western margin, there occur patches or ledges of limestone similar to those described as existing under analogous circumstances in the southern district. To these more particular reference will be made under a subsequent head.

But besides the great belt of slaty rocks above described, there is another of somewhat similar character, though less distinctly marked and of much less breadth, situated westward of the range of the Southwest, Bull Run and Kittoctin mountains, and lying between it and the belt of Gneiss and granitic rock previously described as occupying for a considerable width the region immediately eaat of the Blue Ridge. In this are embraced numerous varieties of Mica- ceous, Talcose, Argillaceous, Chloritic and Steatitic slates, including occasional patches of limestone, and associated at several places with extensive ledges of the Gneissoid sandstone.

Among the slaty rocks of both these belts, many beds occur of a quality fitted for the coarser architectural purposes, such as the construction of walls, steps and flagging. For these uses the mi- caceous gritty slates, of frequent occurrence near the western limits of the eastern belt, seem especially adapted, as well from dieir dura- bility as the smooth slab-like forms in which they are separated from the quarry. The Talcose and Steatitic varieties found in the same belt rather east of the former, where suflSciently solid, are also permanent, and have the advantage of being readily dressed across the grain. All these are occasionally, though not extensively, used in building.

Among the argillaceous rocks of both belts are found ledges of a dark coloured slate, having a texture adapting itlo be used for roof- ing. As yet few quarries have been opened for this purpose, and the true value of the material, at most of the localities where seen, remains to be practically tested. One of the most interesting open- ings of the kind, is that situated about one mile south of the White Sulphur springs in Fauquier county, on the north branch of the Rappahannock river. The rock here is a dark argillaceous slate, forming a ridge close to the river, and about fifty feet in height. Its lamination is nearly horizontal, though rather irregular, dipping sometimes south by west, and sometimes south by east. Many of the seams and joints are stained of a yellowish brown by the iron deposited from the decomposing iron p3rritea, of which small crystals are seen dispersed through the rock. It is this ingredient also that produces the little knots or tubercles frequently seen on the surface of the laminsB ; and thus aided by some slight irregularities of lami- nation, causes the rock to split, with surfaces a little rough and un- even. This range of slate extends in a northeastwardly direction for about two miles, and has been quarried at several places east of the road leading from the springs to Wdrrenton, A similar slate also appears to the west of the road and about half a mile from the springs.

In general, the soil of these belts of slate is of a grej or lifbt brown colour, contrasting strongly with the deep red hue of that produced by the decomposition of the neighbouring Epidodc rocks. In its unimproved state it is far from being productive, but experi* enoe has shewn that it is capable of being greatly benefitted by the use of lime, of which many tracts are provided with a convenient supply in the contiguous patches of limestone.

Epidotic Roeks, — Rocks of the kind here designated, occupy the hilly tract intervening between the two belts of slaty strata above described. They compose the chief mass of the Southwest moun- tain in Albemarle and Orange counties, disappearing in part be- neath the middle secondary rocks in the space between Racoon ford and the month of Robertson river, and in part prolonged across the Rapid Anne river at Barnett's ford, they skirt the middle sec- ondary on the west, and as they are continued in the same general direction shew themselves extensively along the western side of the Bull Run mountain, forming most of Rappahannock and Car- ter's mountain, as well as of the Kittoctin moimtain, throughout its whole extent.

Besides forming the characteristic material of the important belt above described, and of its continuation for some distance towards the southwest, these rocks also occupy a wide tract in many parts of the Blue Ridge, presenting themselves for the moat part in the intermediate space between the Gneissoid and Granitic rocks usu- ally met with towards the eastern base of the mountain, and the sandstones and altered rocks of formation I. lying upon its western flank, or spreading upwards to form its summit.

The rocks under consideration are distinguished by various shades of green, arising from the contained Epidote, which in many instances composes a large portion of the mass, and occasionally presents itself in the shape of distinct crystals grouped together in nests, or forming the margin of the small veins of opaque wbite Quartz with which the rock is always more or less penetrated. They are also remarkable for their hardness and density, but readily lose these characters as well as their colour, by exposure to the weather, becoming in this case loose and crumbly and assuming a yellowish tint, which in time deepens through various shades of orange into red.

In these highly Epidotic rocks, the traces of stratification are doubtful and indistinct, although where observed they are seemingly correspondent with the bedding of the contiguous slaty rocks. Both in the Blue Ridge and in the Southwest mountain and its prolonga- tion, the variety here spoken of has the character of an intrusive rock, elevated by igneous action into and among the adjoining strata. It is often Amygdaloidal, containing kernels of white Quartz and other minerals, sometimes it is vesicular or filled with small cavi- ties, sometimes, again, it is penetrated by thin seams of imperfect Asbestos, while, as already remarked, it is very commonly trav- ersed by ramifying veins of opaque white Quartz. All these char- acters bespeak an igneous origin and ally it to intrusive rocks.

As examples of the many beautiful varietios of this rock and those contiguous to it, met with at various places in the two belts just described, I may mention that between Mountain run and Rac- oon ford in Orange county, where the Epidotic rocks are widely displayed. Near the southeastern boundary of the middle second- ary, they present the following varieties besides the ordinary com- pact green mass :

1st. Epidotic Amygdaloid.

2d. Amygdaloid with drusy Quartz.

Sd. With Ciialcedony and crystallized Quartz.

4th. Quartz with red and white Chalcedony.

6th. Quartz with yellow jasper Amygdaloid.

6th. Brown Semi-Opal.

In the Blue Ridge, at Ashbys gap, where the Epidotic rocks oc- cupy nearly the whole width of the mountain, the following varie- ties are seen :

1st. Light green Epidotic rock compact and fine granular ; some surfaces with small brilliant crystals of Epidote.

2d. Light green Epidote with nodules or kernels of opaque white Qaartz embedded in the mass.

8d. Epidotic rock, Amygdaloidal ; numerous very small reddish kernels, flattened and closely contiguous, contained in a base of reddish and greenish Epidote.

4th. Green slaty Amygdaloid, consisting of numerous small nod- ules of Epidote disseminated through indurated Chloritic rock.

These and other interesting varieties are found associated with the Epidotic rocks, at Thorntons, Swift Run, Turks and Rockfiih gaps, as well as at intermediate points, and continue to be displayed for some distance farther on towards the southwest, but in di- minishing extent. At Thomtons gap and its vicinity, the Amygda- loids are of peculiar beauty, consisting of a Jaspery rock of a rich purple colour enclosing kernels of beautifully white opaque Quartz, each of which has for its centre a groap of radiating crystals of bright green Epidote.

Associated with the highly Epidotic rocks both of the Blue Ridge and the more eastern tract before noticed, we meet with dark green rocks of great density, often including kernels and patches of Epidote, and evidently consisting more or less of this substance as an ingredient diff ased throughout the mass, in combi- nation with Chlorite, Talc, and perhaps Hornblende. These are al- ways distinctly stratified, and are often found associated with gritty rocks, having the character of altered slates and sandstones. In fact, the ponderous dark green slates here referred to, pass by gen- tle gradations into the Argillaceous, gritty and Talcose rocks lying in their vicinity, both in the Southwest mountain and the Blue Ridge, and from this and other considerations, are to be regarded as but modified sedimentary strata, while the unstratified Epidotic masses would seem to have been the immediate instruments in pro- ducing the change.

As remarked in my last report, of the areas in the southern dis-

trictB, similarlj abonnding in Epidote, the soil of the tracts above deeoribed, is always of good quality, containing a marked amount of combined lime, derived from the mineral in question, and to which its productiveness may in some degree be attributed.

O/SUatitie and Serpentine Bocke*

Yarions modifications of these materials are met with interrupt- edly in both the slaty belts above mentioned, but the tracts in which they seem chiefly to occur in the northern district are situated, first in the eastern belt west of the middle of its breadth, in Fluvanna and LouiMa counties ; and secondly, near the eastern boundary of the middle seeonduT' in Fairfax county towards the Potomac. They are also met with rather mdistinctly characterized at various points along the Blue Ridge.

Of the range in Fluvanna and Louisa counties, it will suflSce at present to remark, that it extends in variable width from the neigh- Dourhood of SoottnilUy nearly in the direction of the county line, east of Union mills and between Mechanienille and Newark, Though for much of this distance, its steatitic character is greatly obscured by the presence of a large portion of Talc and Argillaceous matter, at many points the predominance of Steatite is marked, and the rock is a soapstone of moderately good quality. It is here, however, unmingled with Serpentine.

In Fairfax county, as we approach the Potomac, we meet with Steatitic and Serpentine rocks, especially the latter, over an area of considerable extent, evidently the counterpart of the wide tract in Montgomery county, Maryland where the same rocks exist in great abundance. Between Difficult creek and Still House creek, the greenish Talcose slate is seen to include heavy beds of Serpentine and Steatitic rock, including several interesting minerals, among which is Chrome-iron ore. As yet, our researches in this tract are incomplete, and I am therefore unable to affirm any thing of the extent or value of this included mineral ; but future observations directed specially to this point, will furnish the data requisite to form a confident opinion. The following facts in relation to the Serpentine quarry near DranesvilUy will serve to illustrate the character of the rocks and their contained minerals.

The auarry is one and a half miles S£. of Draneeville on the land of Mrs, Sand/ard, The rock which rises in a ridge about 100 yards in width, appears above the surface in ledges, and has been exposed by diggings. The Serpentine is mostly slaty, sometimes in solid layers, nearly vertical, running NNW. with a high easterly dip. Its colour is generally dark green, though sometimes light ; and it is associated with Talc, Asbestos, Carbonate of Copper, Chrome- iron and Magnetic Oxide of Iron. Some of it is Talcose and is quarried as a soapstone. The bed is exposed for a distance of about one fourth of a mile, being enclosed in greenish Talcose slate. The principal minerals found at this locality are the following :

1st. Serpentine, dark green, with small Octohedral crystids.

2d. Talcofie Serpentine. 8d. Green TaJcose slate. 4tli. White Talcose slate. 5th. White Ligniform Asbestos on Serpentine. 6th. Greenish Ligniform Asbestos on Serpentine. 7th. Light green Asbestos, in wrinkled liunellar masses. 8th. Talc, light green, in large leaves. 9th. Chrome- iron.

10th. Green carbonate of copper, containing Asbestos and Ser- pentine.

Quarte Slate or QuarUite,

This interesting rock, of which several localitieiB in the sonthem district were described in mj last yearns report, is foond in nearly the same geological connections, but on a scale of far greater extent in the Biill Ran mountain, and parts of Baldwins ridge and Pond mountain in Prince William county. In approaching Thorough- fare gap from the west, after passing over the Epidotic rocks form- ing the red soil in the neighbourhood of Geargetotniy we come upon the stratified Quartz slate of the mountain, with a dip varying from east to northeast of about fifty degrees. The main mountain is composed of strata from two to four feet or more in thickness, which on its west side presenting their bare outcropping edges to view from a rough broken rocky face, distinctly traceable by its white colour for many miles along the western dope and the crest of the Ridge. About two miles north of the gap, is a high peak of the mountain, composed of these bare white rocks, called Stoney Point. Li the gap, the rock presents itself in a lofty ragged cliff, the fragments of which, in the form of large angular blocks, are seen in the bed and along the sides of the little stream (Broad run) that here cuts through the Ridge.

In the main mass, some of the layers are from 6 to 12 iuches thick. They are generally Micaceous, especially the surfaces of parting. Towards the eastern side of the Ridge, the Mica is more abundant, and the rock here separating with surprising regularity into large slabs, oftn less than two inches in thickness, presents a brilliant coating of silvery Mica. At some points it displays a ten- dency to disintegrate, forming a beautifully white and sharp sand, but in general it is compact and almost crystalline, and of unques- tionable durability. A little east of the mountain and separated from it by a naiTOW plain, occurs a small ridge composed of similar materials, at the eastern foot of which we come upon the middle secondary.

This range of Quartz slate, the most extensive in the state, and the only one of importance in the northern district, becomes an ob- ject of carious interest, not only from the beautiful regularity of its cleavage, and the lustrous surfaces of many of the slabs, but from the consideration that it furnishes a striking example of one of the extremes of composition among the slaty rocks, in which, instead of the usual Talcose, Micaceous and Argillaceous mixtures, we have

an almost exclosively siliceous mass-— of which the parts, though doubtless originallj deposited as sediment, are now united with al- most crystalline compactness.

Pseudo Gneiss or Gneissoid Sandstone.

The class of rocks referred to under this head, and of which, as disclosed in numerous eztensiye exposures in the aouthem district, a somewhat minute account was given in mj last report, occurs under similar geological relations in the district of which I am now treating, being found within or adjoining the belts of slaty rock before described, and near the great Epidotic range of the South- west mountain and its prolongations.

East of the tract of Epiaotic rocks, or more properly, where these become blended with the slates of the eastern belt, several ledges or narrow beds of a Gneissoid grit are met with, consisting of coarse particles of Quartz, with some Mica, and little or no Fel- spar. Being generally divided by smooth and regular joints, they are easily separated at the quarry in the form of prismatic blocks and thick slabs, and being durable and of a light grey colour, are not unfrequently used for steps and sills and other similar purposes. Exposures of this rock may be seen at intervals along the eastern base of the Southwest mountain, adjoining and even among the Epidotic rocks, from the Rivanna tp the neighbourhood of Gordons- tille thence to the vicinity of Montpelier where it is seen associ- ated with a bed of limestone and marble, and adjoining Epidotic rocks and Micaceous and Talcose slates.

We meet with a belt of the same description of rock about three fourths of a mile eastwardly from Warrenton in Fauquier county, in a similar position, associated with Epidotic slates and Trap, and contiguous to a range of Talcose slates on the east. It is here ex- posed over a considerable extent, and has been quarried for the use of the neighbourhood.

But the most extensive beds of these Gneissoid sandstones and grits are met with near and among the Epidotic rocks adioining the western belt of slates. This also is the position in which they are chiefly found in the sontliem district, where, as mentioned in my last report, they present themselves in strata of great thick- ness and extent near the western side of Carter and the Green mountain.

At tlie western base of Watery mountain, four miles west of Warrenton a range of these rocks, consisting of a grey sandstone occurs adjacent to Chloritic slate. The bed has the usual north- eastern direction and steep dip towards the southeast, and furnishes an excellent stone which is quarried for building purposes and for flagging. The rocks of Watery mountain, and most of the space thence to Warrenton are more or less of an Epidotic composition. Similar Epidotic and Chloritic rocks extend westward of the belt of sandstone, so as to form the mass of Carter's mountain and Rap- pahannock mountain, along the western flank of which, on Carter's

ran, we find another and qnite extensive belt of the Gneissoid sand- stone, grey, hard and very siliceoas, in strata several feet thick, and associated with Chloritic slate.

In the same vicinity occurs an interrupted range of limestone, such as we find in numerous other instances near or acoining to the Gneissoid rocks. These strata again present themselves at the eastern base of the Rappahannock mountain, where also they are quarried.

In the range of the beds above alluded to, in a southerly and somewhat westerly direction we meet with gritty Micaceous slates and Gneissoid sandstones and grits, occasionally presenting massive strata of a character adapted for use, as in the vicinity of Jeffenon but most usually in a decomposing state. These cross the Aestham river above Muddy run, and are discovered at intervals thence on to the neighbourhood of CharlotteavillA, maintaining the same general position in relation to the Epidotio belt, but expanding as they ex- tend towards the southwest, and amply exposed as fonnerly de- scribed in Albemarle and part of NeUon county.

Lest the statement above made of the occurrence of these gritty rocks among beds containing Epidote, should be misconceived, I would here remark, that although the greater part of the rocks composing the Southwest mountain, and its prolongations, are dis- tinguished by a greenish colour, and include more or less of Epi- dote in their composition, the amount of Prue Epidote rock is com- paratively small. The other and more abundant masses, upon dose inspection, prove to be various slaty and gritty rocks, containing more or less Talc, Mica, and Chlorite, and impregnated in various degrees with Epidote, either in a diffused condition, or in nests or kernels, and frequently associated with small veins of Quartz. In many instances the impregnation is so slight as to produce little effect upon the colour of the mass, and the character of a Micaceous or Gneissoid sandstone is in a good degree preserved. The rocks in question, though intersected by numberless joints, in general dis- play their stratification with tolerable distinctness, except in the neighbourhood of the bright green epidotic masses, when the planes of bedding are almost obliterated, and the rock partakes of the structure as well as the hue of the Epidote. In view of these facts, there can be little doubt that the strata referred to are bat portions of what was originally one wide belt of slates and gritty rocks, which has been invaded from beneath by the igneous epido- tic masses characterising the range of the Southwest mountain and its prolongations, and that the peculiar hue and texture they present. Is to be ascribed to the modifying actions to which they were thus exposed.

Micaceous and Talcose Limestone and Marble,

Associated with the slaty rocks of the belts already described, we meet with patches, and sometimes prolonged beds of Micaceous and Talcose limestone, passing in some instances into a rock of a grain so fine and uniform as to constitute a variety of marble.

As in the case of the beds of similar materials met with in the Bouthern district, these are in no case to be regarded as continuous for a long distance, but are evidently included masses of a lenticular or oral form, lying in certain belts of the slaty rocks, but not neces- snnly connected with one another. As will appear in the descrip- tion of localities about to be presented, this included foosition is sometimes evinced not only by the meeting of the bounuing strata of slate or other rock at the extremities of the limestone bed, but by their coming together in like form dbote it, thus shutting it out from the surface view, and allowing it to be disclosed only where a ravine or other natural or artificial section removes the incumbent rock.

The following brief account of the exposures of these limestone beds in the northern district, while embracing those of most impor- tance, is not to be understood as including all within its limits. The unfinished state of our researches in many parts of this region, does not admit of a more full enumeration at present. It is quite probable that other localities will be discovered during the explora- tions of the coming season, at the same time severd of those al- ready known will claim further examination.

The range of slaty rocks containing embedded deposits of lime- stone, which in my last report was described as making its appear- ance from beneath the middle secondary, west of Scottmille in Al- hemarle county, and thence pursuing a nearly northeasterly course, shewing at intervals these included calcareous masses ou fiuck isl- and, Limestone and Mechump creeks, is continued in the same gen- eral direction, displaying a bed of limestone about one and a half miles east of Oordonnille in Orange county, and again on the farm of Jfr. Ratolings, about half a mile southeast of the meeting house situated on the road from Gordonttille to Orange court- house.

At these localities, the rock is dark blue and slaty, presenting smooth Talcoso surfaces, and occasional thin veins of calcareous Spar.

West of the former locality, and between it and Mbntpelier we meet with a bed of marble, bearing a striking resemblance to the rock described in my last report as shewing itself extensively on the James river opposite to Warminster. It is white, shaded with pink, with an occasional stain of green Talc. Being of fine grain, and exposed in a solid mass of about thirty yards in breadth at the lo- cality now in view, it would seem to claim attention as a resource likely to be of economical value, and will on this account claim a more minute examination than in a cursory visit we were able to bestow. This bed, which obviously lies considerably west of the range of calcareous masses previously referred to, is contiguous to layers of Gneissoid sandstone, Talcose slates and Epidotio rocks.

Exposures of the calcareous rock, some of them of considerable extent, are again met with on the Kapid Anne river, nearly in the general line of bearing of those above referred to. The most west-

wardly of these occnra nearly opposite the mouth of Suinmerdnck creek on the Ifuad of Mr, Pannill, The riyer being skirted on the south side by a band of the middle secondary rocks, extending inland aboat a quarter of a mile, the slates and incladed limestone are first seen along the soathem margin of these rocks.

This limestone is pinkish and sometimes grey, fine grannlar and sparry, dividing into layers of an inch or two and not solid. It burns into a white lime, and has been used for domestic purposes and for building.

Lower down the riyer, and beyond the termination of the nar- row strip of middle secondary above mentioned, there occur two other leases of limestone of very considerable extent The upper- most of these is found about a mile above the mouth of Brookes run, and is met with inland and in the river cliff. In the former position it is just east of the edge of the red sandstone ; in the lat- ter, the red sandstone is seen to overlap the western side of the band of limestone. The rock at the former point is mostly blue, fine granular, with much calc. Spar, and occurs in layers and masses several feet thick, presenting little or no Mica, Quartz, or other im- purities. The exposure on the river has a width of about twenty yards. The strike or range of the beds is between N£. and NN£., and the dip very high southeasterly. Here the rock is blue, varie- gated with pink, containing much white Spar, and also narrow lay- ers of white Quartz, which project above the weathered surface of the bed. About three hundred yards eastward of this is another and larger bed, about forty yards thick, where exposed in the river bank. It is blue and slaty, coming out in thin layers. In range and dip it agrees with the preceding.

Pursuing the same general direction, we meet with the limestone again on Mountain creek near its mouth, and on the Rappahannock at the mouth of Marsh nm ; the former in Culpeper the latter in Fauquier county. At both localities the rock is exposed rather extensively, and has been auarried and burnt by Captain RoherU and Mr. Whiiely. It is a bluish veined limestone, slightly Talcose and Micaceous, and of slaty structure.

The more western of these Calcareous bed:a, that on Marsh run, continues up the stream and shews itself at the distance of a mile from the river, beyond which it has not been observed. A little further towards the northeast, the range of this and the more east- em limestone bed on Mountain creek, would strike the margin of the middle secondary rocks, and if continued in their original bear- ing, would thereafter be concealed from view by the overlying strata. After this disappearance of the limestone, occurring be- tween Marsh run and Elkton, no beds of Calcareous rock have yet been discovered throughout all the slaty tract bordering the middle secondary rocks, thence on to the Potomac.

Similar interrupted ranges of limestone shew themselves in Fau- quier and Loudoun counties, associated with the slaty and Gneis- sold strata west of the principal belt of Epidotic rocks before described.

One of the most prolonged of these maj be traced along the western base of Rappahannock mountain, and thence on to the neighbonrhood of White Plains, shewing itself on the estates of Mr, NeUoTiy Mr, Grigihyj Mr, Baher and Dr. Homer, The rock varies in coloar and texture, being sometimes of a light blue tint and close grained, and sometimes of a light grey, with films of Talc on the separating surfaces. At Mr, Origtby\ it is associated with green chlorite slate, and is evidently not interposed as a parallel bed, but rather as an enclosed mass, which does not rise uniformly to the surface.

At several points in this range, and especially at Mr, Baher*B the limestone is quarried and burnt quite extensively, and yields a lime which, though not very fair, is found to be well adapted for domestic, agricultural and building purposes.

Further towards the northeast, a narrow bed of limestone occurs near Dover mill, on the Little river, about two miles west- ward of AldUj associated with Micaceous and Argillaceous slates, and a little west of the Epidotio range. Beyond this, in the same direction, are several exposures, north of the road leading from Aldie to Snickers gap, among which may be mentioned the quar- ries of Mr. Luehetty about three fourths of a mile northwest from the junction of the road just mentioned and that leading obliquely across the Kittoctin mountain, to Oatland mills, and that of Mr. Wethered, more towards the northwest and near Goose creek.

At the former, the body of rock exposed is about twenty feet in width, and very indistinctly stratified. It is a fine, granular, blue limestone, not very solid, and making a moderately white lime. A little white silvery Mica occurs occasionally in the seams and on the surfaces of the rock, but not sufficient to entitle it to be called a Mi- caceous limestone. It is associated with greenish Micaceous Tal- cose slates. The rock at Mr. WetherecTa is in the main of similar character, though said to furnish a lime of fairer complexion. Several small ledges of limestone occur in the vicinity of the above, associated with green and whitish Talcose and Micaceous slates.

Other small beds of limestone are known to occur at several points in the same general belt, between the above exposures and the Potomac river, but with the exception of those at Taylortown on Kittoctin creek, about three miles from the river, they remain yet to be examined.

At Taylortown the calcareous masses are enclosed in greenish slaty Talcose rocks, containing iron pyrites, and magnetic oxide of iron in small octahedral crystals, with some whitish Tremolite, Actyn- olite in greenish fibrous masses, and a little Asbestos.

The most easterly of these beds consists of a bluish limestone, much of which is shaded or striped with lighter and darker tints irregularly disposed over the surface; and from this, as well as its texture, deserves to be regarded as a pretty variety of marhle. At the quarry opened on the side of the hill, about thirty or forty

feet above the creeic, the body of limestone exposed is about ten feet thick, and rather diminishes than increases in descending. The green indarated Talcose slate adjoining it on both sides, bends over and covers the limestone on the top, so that there is several feet of slate between it and the surface, thus affording an interesting exam- ple of that inclusion already mentioned, characterizing these lime- stone masses generally. A similar rock, the continuation of the former, is also quarried at the milL

West of this, and separated from it by about twenty feet of hard green slaty rock, are several layers of beautifully white marble, of an admirably fine and uniform texture. The layers are solid, free from veins, and would seem capable of being extracted in masses from one to two feet thick and several feet in length. Were the deposit of greater extent, preserving the colour and texture of that now exposed, it might prove of high value for the finer uses to which this material is applied, having the pure tint, and the fine even yielding grain of marble alabaster. It should be added that both this and the blue variety appear to be susceptible of a good polish.

Of the chemical composition of the limestones collected at the various localities above described, a detailed account will be given in the concluding chapter of the present report. On this head I need only remark, that like those met with under similar circum- stances in the southern district, and of which a minute description was given in my last report, although in general less free from earthy admixture than the limestone west of the Blue Ridge, they furnish a lime capable of being very usefully applied in agriculture, as well as for household and building purposes ; and that as regards the first of these applications, they aeserve to be considered as a valuable source of improvement to the soils of the prolonged belt in which they occur.

In the brief sketch that has now been given of the Primary and Metamorphic rocks of a considerable portion of the northern dis- trict, I have confined myself to such particulars as could be most readily presented in a compendious form, and as had been slightly or not at all alluded to in preceding reports.

To the numerous details in my possession, omitted in this sketch, are to be added the results of the further researches necessary for the completion of our labours in this portion of the state, in order to enable me, in my final report, to present a minute and compre- hensive picture of its geological structure and important mineral contents.

As formerly remarked, an important portion of the northern district is occupied by a class of rocks entirely different from the Primary and Metamorphic masses I have been describing, and which constitute the middle secondary formation of this part of the state. These I will now proceed to describe.

Chapter V.

OF THE MIDDLE SECONDARY SANDSTONES, SHALES AND CONGLOM- ERATES OF THE NORTHERN DISTRICT EASl OF THE BLUE RIDOE

Section I.

General Features qf thu Formation.

The close resemblance existing between the strata of the middle secondary formation as presented in the region now nnder consider- ation, and that sonth of the James river, was referred to in my last year's report, w!jile treating of the southern district, and the gen- eral description of the middle secondary rocks then given, was de- signed to apply as well to the northern as the southern tracts in which they are developed. It will therefore be unnecessary in this place to repeat these descriptions in detail, and it will suffice be- fore entering upon the brief sketches that are to follow, in a few words, to remind the reader of the general character of these rocks, and to point out one or two particulars in which, in some parts of the northern tract, they present peculiar features.

In th first place these strata are all of the sedimentary charac- ter, consisting of particles of sand and earth and pebbles of various dimensions, derived from pre-existing rocks, and deposited by water in the positions they now occupy in the masses of which they are the component parts. Through all the variety of texture, com- mencing with the coarsest conglomerates including pebbles of many inches diameter and passing by successive bteps to strata composed of finer and finer materials, constituting the sandstones, slates and shales of the formation, we meet with unequivocal proofs of this aqueons origin, and at the same time, unless in certain localities where subsequently to their deposition they have been invaded by igneous rocks from beneath, we find no indications of their having been subjected to those modifying agencies, due to igneous caases, from which the metamorphic rocks of which I have been treating in the previous chapter have derived so much of the character they now present.

Though of various tints, comprising grey, brownish grey, green- ish grey, brownish yellow and others, these strata as a group are marked by the predominance of a red colour, which is however more particularly prevalent among those of a shaly texture.

With a few local exceptions, their dip is to the north of north- west, and the inclination, though variable, is usually small, thus con- forming precisely to the position of the corresponding rocks in the southern district.

They here also, as in that part of the state, contain impressions of vegetable stems and leaves converted into Lignite and coaly mat- ter, and in a few localities they preserve distinct traces of the re- mains of fish, especially the well characterized rhombic scales men- tioned in my last report as discovered at several points in the middle secondary rocks of the southern district.

The coarse conglomerate or breccia is met with here, as in the Bouthem district, chiefly along the western margin of the formation, but with this peculiarity, in the neighbourhood of the Potomac and one or two other points, that a considerable proportion of the em- bedded pebbles consist of limestone — thus converting the mass into the rock well known under the name of Potomac marble. As in- dicating the cause of this local peculiarity of composition, besides referring to what was said on the subject in the report of last year, I may observe that in Maryland not far from the Potomac, an ex- tensive range of limestone displays itself a little eastward of the margin of the conglomerate, the more eastern portion of the middle secondary rocks, which by their position would have rested upon this limestone, being wanting over a considerable space, and that this limestone in its prolongation towards the southwest, disap- pearing beneath the middle secondary rocks, before reaching the Potomac, is in all probability continued for some distance in this buried position near the eastern margin of the conglomerate. In such a view, the source of the calcareous fragments contained in the conglomerate met with near the Potomac, would be no less ap- parent than it is in other positions where beds of limestone are met with along the eastern margin of the middle secondary belt.

Referring for further details in regard to the various character- istic features of the formation, to my report of last year, I pro- ceed to give a compendious account of its boundaries, and some of its component strata as it displays itself in the northern district.

Section II.

Boundaries of the Middle Secondary Formation in the Northern Die*

triet.

Before proceeding to describe the boundaries of the formation, it is proper to remark that, as with the exception of one short inter- val near its southern extremity, it is continuous from the Potomac to that point, it will be most convenient to describe the whole in one connection — reserving tlie special account of the boundaries along the deficient space, which are yet not precisely settled, for the more minute delineation hereafter to be given. I would also remark, that although in thus briefly tracing the outline of the area in question, reference will be made only to points most easily rec- ognized on the map, and often, therefore, at very considerable dis- tances apart, the greater portion of the boundary has been explored at nmch smaller intervals, so that with the exception of some miles between Leesburg and the Potomac, in the neighbourhood of Nolauds ferry, and several short lines towards the southwest, the limits of the area have been accurately traced. I may therefore be allowed to repeat the suggestion made in my last report, that the reader desirous of having a distinct picture of the position and form of this important portion of the northern district, should fol- low the description here given, pencil in hand, and thus trace for himself an approximate outline of the region on the map.

The general form of this area is that of a prolonged triangle, extending in a direction from SSW. to NNE. naving its apex at the southern extremity, and gradually expanding until it reaches the Potomac. Measured from the apex to a point on the Potomac midway between the mouths of Goose creek and Broad run, its length is about eighty miles, but including the narrow tract extend- ing northwardly from Lee$burg to the neighbourhood of Nolands ferry, it would be increased to near eighty -eight miles. Its great- est breadth, as measured near the Potomac, and parallel to the road leading from Leeiburg to Dranewille is about fifteen miles. This, in round numbers, gives nx hundred Mua/re miles for the area of the middle secondary region in the nortnem district.

Beginning at its southern extremity, about a mile SW. of JBaV' hoursville in Orange county, the boundary of the small area lying to the southwest of the interruption above alluded to, may be traced by a line drawn a little east of the upper part of Blue run, and par- allel to the stream as shewn on the map, undl this line passes the mill below Brewer branch, continuing in the same direction parallel to the SW. mountain, so as to pass a little west of Montpelier, and striking the turnpike leading from Orange courthouse to Stanards- ville, at the eastern crossing of Poplar, alias Baylors run, thence bending round towards the northwest, so as to strike the Rapidann river at a point not yet determined, near the mouth of Poplar run, then turning towards the southwest, passing in that direction a short distance east of the mill where the turnpike touches the river, continuing on a little westward of the meeting house and of Bar- houratille, and thus returning to the point at which the tracing was commenced.

As already mentioned the interval between this and the princi- pal tract lying to the NKE. has only been partially explored, and I am therefore unable, with precision, to lay down the position of the boundary of that portion of the tract southeast of tne junction of the Robertson and Rapidann rivers. Much of tlie interval is occupied by the Epidotic rocks forming the prolongation of the Southwest mountain, which are continued in considerable breadth to the neighbourhood of Racoon ford, and at the same time extending in a northwestwardly direction across the Rapidann at Bamett's ford, send out a spur, or another but interrupted range, seen at intervals thence towards Culpeper courthouse. For the present considering the boundary of this part of the tract as coinciding with the course of the Rapidann river, from the mouth of Robertson river to a point a little above Racoon ford, the eastern margin of the prin- cipal area may be traced by a line drawn through the points and in the directions described below.

Commencing at a point on the south side of the Rapidann, about three fourths of a mile above Racoon ford, its course nearly due east diverges slowly from the river until it touches the road be- tween a half and three quarters of a mile towards the south ; it then bends a little northwards and curving around so as to strike the river about a mile above the mouth of Brookes run, where the

limestone and middle secondary are seen in contact, it crosses the Rapidann in a northeastwardly direction, passes Brookes run a short distance above its month and intersects the road leading from 6erm> anna ford to Stevensburg, at a point a little west of the fork near the meeting-house laid down on the map. Thence bending slightly more towards the north, it crosses Mountain creek near the second mile above its mouth and strikes the north fork of the Rappahan- nock, a short distance above the mouth of Marsh run. 'Now pursu- ing a course almost due northeast, it strikes the head of Elk run a little distance east of HiekerMn'$ at the cross roads, and turning rather more towards the north passes west of BrentvilU and east of New Marhety so as to cross the turnpike from CentrevilU to War- renton near the western verge of the former. From CentretilUy con- tinning in nearly the same direction, it intersects the turnpike lead- ing from Alexandria to Winchester about four and a half miles west- ward of Fairfax courthouse, and thence prolonged crosses the road from Oeorgeioum to Leetiburg at DranesrilU, situated on that road due south of the upper end of Beech island as laid down on the map. Continued from this point, it strikes the Potomac river at a point not yet precisely ascertained, about one or two miles below the mouth of Seneca creek in Maryland, Of its prolongation in Maryland, it will be enough to say, as supplementary to the tracing just given, that after crossing the Potomac it quickly bends around to the north and then to the northwest, so as to pass over the Sen- eca between the mouths of the Dry and Little Senecas, and to in- tersect the Little Monocacy, some distance above its mouth, whence turning to a northern and afterwards a NE. course, it crosses the Big Monocacy very obliquely, and shews itself on the Baltimore and Ohio rail-road, immediately west of the limestone before referred to, evincing in the remarkable change of its course, after crossing the Potomac, the great contraction of the middle secondary area, which was mentioned in the same connection as occurring in this region.

Returning now to the southwestern extremity of the tract for the purpose of tracing its western margin, we find it marked out by a line passing through the points and having the directions enu- merated below.

Beginning at the mouth of Robertsons river, its course, though not yet minutely ascertained in this vicinity, is such as to intersect Oedar run a little eastward of where that stream crosses the road lending from Fairfax ( Cvlpeper courthouse) to near the mouth of Crooked run. Thence it continues so as to strike the road in ques- tion about two and a half miles south of Fairfax, and parsing a little west of the village, extends to Muddy run near the principal bend. From this point, its course, though not exactly determined, carries it across Aestham river, near the mouth of Muddy run, and Hedgeman's river, a little below Freeman's ford, and thence on to a point on the road from Warrenton to ElJcUm about one hundred yanls west of Turkey river. Pursuing the same direction until it passes the southern end of Baldwin ridge, it curves around so as to

take a more northerlj coarse, and keeping close along the eastern flank of Baldwin ridge and Pond monntain, crosses the road lead- ing through the gap, about one mile eastward of New Baltimore, Thence continuing its course along the eastern flank of Pond moun- toin it intersects the road leading to Georgetown bj Thoroughfare gap, about a quarter of a mile east of the milt at the eastern end of the gap. Extending along the base of BuU Run mountain, in a nearly uniform course, it crosses the Aldie turnpike about a fourth of a mile east of the village, thence runs nearly parallel with Little river for some miles, and passes Goose creek at Carter's mill, (Oat- land mills on the map,) and adhering closely to the flank of Kittoctin mountain, passes a little west of Leeshurg, touches Limestone creek near its head and in the vioiuity of Matthews store, about six miles KNE. of Leesburg, and thence continues to a point not yet deter- mined in the neighbourhood of Poland's ferry on the Potomac. Its extension in Maryland preserves a course nearly parallel to the Monocaoy river, and to the eastern boundary line before traced, after that line has crossed the river, the two being thus made, in this part of their course, to comprehend a very narrow tract, chiefly occupied by the calcareous conglomerate.

Section IIL

Character and Contents of the Strata and of the Associated Trap

Bock.

The chief peculiarities of the middle secondary strata in the tract now under consideration having already been alluded to, and their more important varieties as to texture, colour and contents, having been described in the report of last year, when treating of the simi* lar materials of the middle secondary tracts in the southern district, I shall content myself with only a few additional illustrations, drawn from localities within the area of which I am now treating, and as for the present, these admit of being most easily presented in the form of brief summaries of the several varieties of rock met with in passing across the region at various points, I shall introduce them in that shape.

In entering upon these descriptive sections, it should be premised that the protruding masses of igneous rock, of the nature of Trap, met with even more freauently in this than in the southern tract, constitute, in a geological point of view, one of its most interesting features* These intrusive rocks, which, forced up from beneath by igneous agencies, have penetrated either partially or entirely through the middle secondary strata, are readily distinguished from the en- closing sandstones, slates and shales, by their dark grey and nearly black colour in the interior, and the ochrcons brown hue they as- sume when weathered, by their great hardness and heaviness, and by their not appearing in regular strata, but in knobs and ridges, breaking down by exposure into masses of a rounded form, from a few inches to several feet in diameter.

These knobs and djkes, thongh not nsaally of great extent, are exceedingly numeroas in many parts of the tract, giving a rugged- ness to the surface which it would not otherwise present. Where appearing in the form of true dykes or walls of Trap, rising through the acacent strata in a nearly yertical direction, they may some- times be traced longitudinally for a distance of a few miles, and are then seen to have directions, which, though by no means regular, are generally towards the west of north. But few instances, bow- ever, occur, of their being prolonged with sufficient distinctness to admit of determining their bearing in a satisfactory manner, and (for the most part) they present themselves as isolated knobs or short ridges, with no traceable connection on the surface.

The modifying influences of these igneous rocks upon the adja- cent strata, exemplitied in my report of last year, with reference to certain localities in the southern tract, are observable also in nu- merous places in the northern area, the strata in the immediate vi- cinity of the knobs or dykes of Trap, though but little disturbed in position, displaying in such cases various remarkable changes as to texture, colour and composition. In most cases, the alteration thus produced does not extend beyond a change of colour and in- creased hardness and density of the modified mass, but at some lo- calities it is marked by the development with the substance of the altered rock of various crystalline minerals, among which Epidote of frequent occurrence, sometimes distributed through the roaaa, but more commonly collected in the form of oval or spherical ker- nels, like those of an Amygdaloid. As locally illustrating the order of succession of the middle secondary strata and the mode of oc- currence of the igneous rocks among them, I proceed now to a brief description of several sections as above proposed.

Taking as our first illustration the transverse line marked out by the road leading through Dranesville to Leeshurg, comprising a breadth of upwards of foarteen miles, we find the middle second- ary and igneous rocks to occur in the following succession :

Immediately west of the small ridge on which DranemilU stands and which is composed of micaceous slates, we meet with the red sandstone of the middle secondary, consisting of layers alternately hard and soft and including some conglomerate. This continues alternating with greenish slabby sandstone and red shale, as far as Broad run. Many of the beds presented in this interval are of sufficient firmness and durability to be used in architecture, and have accordingly been employed in constructing the bridge over Sugar- land creek. The greenish sandstone is of a variety met with at numerous other localities, being remarkable for containing the re- mains of vegetable stems converted into coaly matter, and coated in places with green carbonate of copper, the rock itself also present- ing thin films and disseminated particles of this substance. At Broad run, occurs an extensive dyke of Greenstone Trap crossing the stream obliquely, with a bearing or course of NNW. and a dip of sixty degrees to WSW. At tlie eastern end of the bridge, it rises like a great wall, spontaneously dividing into layers from one

4:77

to two feet in thickness, and presenting at the first glance the as- pect of a hard Sandstone or Gneiss. Its width is ahout 150 yards, and on the western side it displays the usnal tendency to the globu- lar form. Beyond this, with some reddish slate, we have grey and ash coloured slaty sandstone; and about a mile before reaching Goose creek, we come upon another range of green stone, beyond which we are again presented with the radish and light coloured shales and sandstones. At Goose creek, the green stone is re- peated, forming a broad dyke running N. a little W. and nearly ver- tical, and in about a fourth of a mile further on we have another dyke of the same material, about 20 yards in width, rising abruptly on the south side of the road like a solid wall. Between the two dykes last mentioned the sandstone gives striking evidences of al- teration, presenting itself as a hard, compact, fine-grained rock, of a mottled and grey aspect, at first view bearing some resemblance to a green stone. It also exhibits a jointed structure conforming to that of the igneous masses in the neighbourhood, and obliterating its original stratification. Beyond this we have altered sandstones and shales, with green stone, to Leesburg. "Within the town a small range of green stone, and in various directions in the neigh- bourhood are abundant exposures of the conglomerate. The latter rock is characterized in this part of the tract, as formerly men- tioned, by the large proportion of limestone pebbles it contains, as well as the amount of calcareous matter diffused through the mate- rial by which they are cemented together. At Col. Shreeve a quar- ter of a mile from the town, in a southern direction, it is so rich in carbonate of lime as to be quarried and burnt as a limestone, af- fording a lime well suited for building and agricultural purposes.

Taking as another illustrative section, the line of the turnpike road leading from Fair/ax courthouse to Aldie, we leave the red micaceous slates of the primary region about fuur and a half miles westward of the courthouse, and immediately enter upon the mid- dle secondary tract. The rocks here are red sandstones, of moder- ately fine grain, in compact layers of sufliicient hardness and durabil- ity to be valuable in building. These continue for some distance, occasionally alternating with red shales and brownish sandstones ; and at about six miles from the courthouse we meet with the green- ish sandstone containing vegetable stems converted into coal, which, as well as the rock itself, is sometiiqes stained by carbonate of cop- per. Next we meet with a small dyke of greenstone Trap. Thence we pass to red and brown micaceous sandstones of fine grain, and these, with occasional beds of similar colour but coarser texture, to- gether with several small ranges of green, occupy the next four miles. The rocks are now observed to become more soft and shaly, and continue with this character until within about three and a half miles of Aldie when we meet with the coarse conglomerate usually found near the western margin of the tract. Beyond this, we have the red sandstone again for a short space, then a range of globular greenstone, followed by soft red shales, containing bard layers of sandstone; after which, occur two more ridges of greenstone, with

a small interval occupied by soft red and green sLales ; and finaU j, a width of about one hundred yards of these shales form the west- em margin of the middle secondary about one fourth part of a mile east of Aldie,

Referring next to a section in the line connecting ElhUm and Warrenton still beginniog our observations at the eastern bonnd- ary, we find at the former point associated with the red brown and grey sandstones, a dense slaty sandstone of an olive green colonr, smoothly laminated and of remarkably fine grain. These red, brown and grey rocks continue for about one mUe, when we come upon a range of green stone running north and south, two hun- dred yards in width. This rock is coarse, consisting of greenish Hornblende and white Felspar, both quite distinct, and the latter m some specimens so abundant, as to give the mass the appearance of a Sienite. Beyond this, the sandstone is dark green ana slaty, bear- ing marks of having suffered some alteration from its proximity to the igoeous mass. This is succeeded by red shale, which soon gives place to another range of green stone much decomposed and weath- ering in the globular concentric form. We now have green slaty sandstone followed by red sandstone and red shale, which with the addition of another small range of green stone occupy the remain- der of the distance to Germantown (Shumates) near Licking run. Here we are presented with the igneous rocks on a more extensive scale, not in the form of a regular dyke or ridge, but as a number of protruding knobs or short ranges sometimes seen to coalesce with one another. The rock displays much variety of composition at different points. Towards its western edge it consists of globu- lar concretionary masses of a dull greenish colour, embedded in a paste of similar aspect and composition. It here contains nodules of Chalcedony, enclosing crystals of Quartz, some of the Chalced- ony being disposed in numerous layers slightly varying in colour and thus forming a species of Agate. From this onwards the red sandstone and shale, with occasional bands of greyish and greenish sandstone, continue to within four miles of Warrenton where the igneous rock again appears in considerable force, crossing the road seemingly in detached ledges for a distance of half a mile. Termi- nating on the east side of Turkey run, it is followed by a narrow strip of the red sandstone on the opposite bank, which here forms the western margin of the midlMe secondary rocks, about three and a half miles from Warrenton.

As indicating the character and succession of the strata still more towards the south, an oblique section passing from the east- ern margin near the Fork meeting-house, through Stevenfiburg to Fairfax {Gulpeper courthouse), will serve to complete the illustra- tions on this head, as far as they can with propriety be presented at this time. Commencing at the point above mentioned, which is about six miles eastward of Stetenshurg after quitting the mica- ceous and other primary slates, we come upon the red shales of the middle secondary. These are soon followed by greenish and bluish slates, fine grained, compact and hard, and separating in slabs suit-

able for building. To these succeed red shales and sandstones, gen- erally of line teztare, with which are associated bluish and greenish sandstones and shales, frequently calcareous, and in some layers consisting of shot-like grains, containing a niarked amount of car- bonate of lime, and slightly filmed with green carbonate of cop- per. Within about one and a half miles of Stevensburg we encoun- ter a dyke of green stone, of the variety commonly called Iron stone, of coarse grain and great hardness, and separating in large spheroidal masses. Adjoining this, the shale is of a greenish or olive hue, and greatly mdurated. Similar altered rocks continue for most of the distance to Stevensburg presenting in some of their layers spots and distinct concretions of semi-crystalline matter of a lighter colour than the enclosing mass — evincing, even more strik- ingly than the increased hardness and heaviness of the rock, the modifying agency of igneons causes. Proceeding westwards, we have frequent alternations of bluish and red shales, as far as George- toien before reaching which, and just opposite the foot of Mount Poney, we meet with the anomaly of a northeastern dip among these rocks. Beyond Georgetown the shale, continuing its eastern dip, exhibits striking marks of alteration, having nearly the hard- ness of Homstone, being specked with semi-crystalline matter, and so intersected with joints as almost to obliterate its stratification. This is soon followed by heavy beds of conglomerate, chiefly made np of huge pebbles, sometimes six inches in diameter, consisting of Epidotic, Chioritic and other rocks of the primary region, embedded in reddish shaly matter. These alternating with red shale and sandstone continue to the courthouse.

In connection with these details, it is proper to mention that similar marks of alteration from igneous causes, are observed in nearly all the middle secondary rocks lying in the tract between Fairfax and Racoon ford. Indeed, in many instances, their semi- crystalline texture, density, dark olive green colour, and tendency to vertical cleavage, and something approaching to columnar form, give them at first view the aspect of some of the igneous rocks to whose agency they are no doubt indebted for the curious modifica- tions they have sustained.

In alluding to the contents of the middle secondary strata in the various sections briefly described above, mention has been made of the occasional occurrence of coaly matter and of an ore of copper among them. In several localities the former has been met with, associated with a black wafery slate, having much the appearance of the shales often found adjacent to seams or beds of coal. This fact, taken in connection with the general resemblance of the mid- dle secondary strata to those accompanying coal in other regions, has given rise to the opinion that valuable deposits of that sub- stance are to be found among these rocks, and has led to explora- tions by means of diggings at various points where, from the dark colour and bituminous character of the slates, the object sought for was thought most likely to be concealed. In regard to this expec- tation, I feel called upon to remark, that after much careful ob-

Bervation, at the points where openings have been made, as well as elsewhere among analogous strata, and after an attentive inspection of the middle secondary rocks thronghont the entire tract, I see no gronnd whatever for anticipating the discovery of any tme coal seam within its limits, and that, as in the case of the southern tracts referred to in my report of lott year, the coaly matter occa- sionidly associated with these rocks, is contained in them only as derived from the vegetable remains scattered through some of the layers, or as films or thin seams of merely local extent

Hopes not less sanguine than those above alluded to, have like- wise been excited by the existence of the carbonate and other com> pounds of copper in the shales at several localities, and mining enterprises of no inconsiderable extent have been undertaken to explore the strata for these materials. But at none of the openings thus made, and in no parts of the middle secondary tract where the ores Qf this metal have been met with, have they presented them- selves in sufficient quantity or in proper form for aavantageous min- ing. Besides the green carbonate already mentioned as of frequent occurrence in the shape of films and specks, often associated with vegetable impressions, and contained in calcareous shides, the phos- pliate and sulphuret have also been met with at several localities, but thoagh sometimes in sufficient amount to furnish cabinet speci- mens of great beauty, the diffused condition in which they have thus far always presented themselves, furnishes no reasonable gronnd for the hope of meeting with them in a regular vein or de- posit, likely to be of economical value.

Chapter Vl

EASTSRK DTVTSIOir OF THE SOUTHERIT PRIMARY DISTRICT AJUD THE COAL FIELDS OF CHESTERFIELD POWHATAK, QOOCHLAIfD AKD BEKRICO OOUKTIES.

Our observations in the portion of the primary reon lying south of the James river, not previously explored, were conducted by means of numerous transverse sections, extending from the east- em boundary of the primary rocks to a line passing through Cum- herland Prince Edward Charlotte and Halifax courthouses, this line marking the general eastern limit of the explorations of preced- ing seasons. Combining with these the examinations made at in- tervening points, and connecting the whole of the results thus obtained with the minute investigations of former seasons in the westem division of tiie southern primary tract, we are furnished with all the materials necessary for forming as correct a picture as need be desired of the geology of this widely extended area.

. As an important part of our observations in the district under consideration, and in that adjacent to it on the north, some time was devoted to the determiDation of the boandaries of the coal re- gion in Chesterfield and P<nchatan counties, and of its counterpart

on the north side of the rier in Henrico and Oooehland counties, as well as of the small tract lying more towards the northeast, formerly referred to as the Dry ran basin ; and in addition to these observa- tions, chiefly confined to the margin of the areas occupied by the coid-bearing rocks, several sections were made across tnese tracts, and varioQS details collected in regard to the workings now in prog- ress, not previously obtained.

Omitting at this time a particular account of these observations, as being for the most part uninteliigible without the aid of a geo- logical map and sections, I propose first, to describe briefly the course of several of the more important lines of section explored in the region on the south side of James river — stating in few words the prevailing characters of the rocks exposed; and secondly, to trace the outbnes of the coal districts with as near an approach to accuracy as can be attained by referring to the state map.

The first section commences at Falling creek on the jBuehingham road, and extends by Powhatan courthouse to Oumberland court- house. The first eight miles nearly of this distance is' across the coid field, presenting therefore no rocks but the sandstones, grits and slates of the coal measures. Beyond this, we have numerous alternations of Gneiss, Granite, Sienite, Hornblende Slate, Horn- blende Gneiss, with occasional beds or dykes of Trap; and veins and beds of Quartz. The dip, among the stratified masses, towards the southeast, and generally at a high angle. This connects with a section previously constracted, fVom Cumberland courthouse through MaynillOy Warmin$ter and LotingUm to the western side of the Blue Ridge at Tye river gap.

The second section extends from Petenrg by Amelia court- house to about three miles beyond lAgonUncn on the Appomattox river. This line of observation, lying a little south of the southern end of the coal field, is at the moutn of Winticomack creek, doea not contain any of the coal rocks, but displays a broad band of pri- mary slates a Uttle east of what would have been the extension of coal field. In other respects the rocks presented along the sec- tion agree in general character with those of the preceding.

The third section commences at a point on the Petersburg and Roanoke rail-road, about ten miles south of Peteniburffj and passing through Dinwiddie courthouse and NotUneay courthouse, termiuAtM at Prince Edward courthouse. The rocks chiefiy met with are Gneiss, Sienite, Hornblende, Slate and Trap, together with the ex- tension of the band of primary slates noticed in the last section, which is here contracted to a much less width.

This connects itself with a section previously formed, extending from Prince Edward courthouse through Amhirst courthouse, and over Long mountain to the Blue Ridge.

The fourth section extends from iellfield on the Meherrin river, through Brumwiek and Lunenburg courthouses to Charlotte court- house. The chief peculiarities presented in this line, are the in- creasing abundance of the Hornblende Slates and Hornblende Gneiss, the occurrence of Chlorite, associated with numerous bands of

Qaartz towards its western termmation, and the entire disappear- ance of the belt of primary slates towards the east. This sectioo unites with a previous line of observation extending from Charlotte oonrtbonso through Campbell courthouse, New London and Liberty and terminating in the valley beyond Bnford*s gap.

The fifth section commences at Bellfield, and extends through Boydton to Ahhyville on the Staunton river. The most marked peculiarity observed in this line is the increase of Ohlontio and Tal- cose matter in the rocks observed between Boydton and Staunton river, and the occurrence of beds thus impregnated, of a quality ad- mitting of their being wrought as a variety of soapstone.

The sixth section extends from Weldm in North Carolina through Ridgway and Clarkwille to Halifoa courthouse. On this line, the greenish Ghloritic and Talcose rocks are largely expanded between Midway and Clarhnille. The Roan(ke exposes in its course extensive and valuable bodies of Sienite and Uornblendio, as well as Felspathic Gneiss, furnishing excellent building materials, which have attracted attention and are worthy of being extensively wrought. This section, terminating at Halifax courthouse, unites there with a previous line of observation, extending through Com- petition and Eoehy Mount in Pittsylvania and Franklin counties to the Blue Ridge near the Bent mountain.

In the detailed profiles of these and other sections now in prog- ress of constraction, the several important bands of rock will be laid down in their proper order and proportion, and with their ob- served dips, so as, in connection witn lateral observations, to con- vey a more faithful representation of the geological structure of this region than would be practicable by any amount of merely ver- bal detail.

Proceeding now to a compendious sketch of the outlines of the coal regions lying in Chesterfield Powhitan Henrico and Gooehlcni counties, we may commence our tracing on the southern bank of the James river, a little west of the United States arsenal. From this point it extends in an irregular line, having a general direction nearly due south to the Chesterfield turnpike, which it crosses about two hundred yards west of Falling creek and near the well known Black Heath pits. Hence continuing nearly in the same direction, and maintaining a course a little east of the road leading from the pits, south to the Genito road, and passing through the western

1>art of St. Leger farm, it crosses Swiit creek a short distance be- ow the mouth of Dry creek. Continuing in this direction and a little east of Dry creek for a short distance, it now bends around to a more westwardly course, and striking the creek near its head is prolonged in a line about S. W., which runs east of Winterpook creek, until within about half a mile of the Petersburg and BeviVs bridge road where it crosses it, and maintaining nearly the same course strikes the Appomattox river about one mile above Eppess falls.

From this point the boundary of the coal rocks coincides with the course of the river as far as Winticomack creek, little or no in-

dkations of these rocks being met with on the south side. At the month of Winticomack and for a very short distance np the stream a small patch of them is seen, hnt unasaociated with coal. Now abniptlj taming to the northwest and following very nearly the course of the river, the boundary line strikes very obliquely across and is marked by primary rocks about one mile below BevU'a bridge, whence it passes to the mouth of Sappony creek and follows the course of the river to near Goode's bridge, presenting one or two small patches of the coal rocks on the south side. From this point, assuming a course nearly due north, it crosses the road from CoUsville to Qenito about half a mile east of Skinquarter creek, and continuing a little east of that creek, crosses the road from Chesterfield courthouse t6 Genito, about half a mile from the Btream. Thence it is extended so as to intersect Swift creek about one mile below the road from Genito to the main Buelingham road, and crosses the latter about half a mile east of their junction. From this, it bends more eastwardly, pursuing the Dittoway branch of Joneses creek, and then the creek itself for some distance, it crosses the James river in a line east of northeast, passing on the north side by Dover chnrch and intersecting the broad branch of Tuckahoe creek a short distance above its mouth. Continued thence, it intersects the Three Chopped road a little east of Big Tuckahoe cieek and rounds off in the triangle formed by the Manakintown ferry road, the Pounce's Tract road and the Three Chopped road. Now re- crossing the last named road about half a mile east of Little Tucka- hoe creek and intersecting the Main Tuckahoe near "Woodward's pits, it continues to the James river, which it strikes opposite to the point at which the tracing commenced. The length of this area from its most northern to its most southern termination is about thirty miles. Its greatest breadth about eight miles.

In the outline as above sketched, no notice is taken of the small outlying basins on the eastern margin of the field in Chesteield or of the narrow prong of coal measures lying west of Jones's creek on the south side, and west of Sampson's hill on the north side of the river. This prong presenting itself as u very narrow and shallow baMn on the north side, extending but a short distance from the river, coalesces with the main basin on Dittoway branch and the upper part of Jones's creek, the ridge of primary rock by which it is cut off gradually flattening down as it extends southwardly. In a similar manner, several other ridges of primary rock entering the basin near its northern margin, divide it into a number of small di- verging branches, each of which has its proper boundary, but all, by tlie flattening of these ridges, coalescing not far from the general outline above laid down. The shape and manner of connection of these branches with the main field, as well as the form and position of the small outlying basins, can only be made apparent by a prop- erly constructed map.

Nearly opposite to the extreme northern part of this cool field, and separated by about three miles of primary rocks, lies the small coal tract, known as the Springfield and Deep Run bas!n. It is

about two miles in length and a qnarter of a mile in width, its most sontherD termination being near Deep Run charoh, its most northern a short distance south of Ghiokahominj river.

CHAPTER VIL OPEBATJOirS ly THE GREAT WESTEHN COAL BEGIOK.

Seotioit I. General Sketch of the Region escphred.

In presenting the following brief sketch of our operations dur- ing the past season, in the great western coal region, it maj be well to remind the reader of tihe general features of this extensive tract, as described in my report of last year, and to recur to the seyeral groups of strata, which, according to a regular order of superposition, present themselves in successive zones upon its sui face. Bearing in mind that this reon forms a part of a vast basin of coal-bearing rocks, whose eastern margin entering our state from PenneyUania passes entirely across it into Kenttiel and Tenn£9aeey it will at once be obvious that the lowest of the series of strata which it includes, however deeply buried ,by the incumbent rocks towards the centre of the area, must make their appearance upon its surface throughout a zone of greater or less width lying immedi- ately within the boundary of the basin, and that groups successively higher and higher in the series will be brought to view in zones lying still more towards its interior. The general northwestern dip of the strata on the Virginia side of the great basin from the Penn* eylvania to the Kentucky line, and their southwardly dip toward- its northern extremity, indicate the direction in which lines of ob- servation should be chosen best suited to develop the various strata comprised in each of the great groups, while they evince the impor- tance of the natural sections formed by tlie Great and Little Kana- wha, the Sandy and other westwardly flowing streams, as well as of the Ohio river throughout its entire course along the western bounds ary of the state.

Examinations made along these lines, as well as shorter sections, together with extensive longitudinal tracings of particular seams of coal and their accompanying rocks, have shown that the series of strata by which this vast surface is overspread, observing a regular order of superposition, naturally arrange themselves into four great groups. The first or lowest of these groups, resting on the coarse sandstone or conglomerate of formation XII. described in former reports as constituting the floor upon which the coal measures are outspread, containing several seams of coal, of which generally one, and sometimes two or three are of sufficient extent to be of great economical importance, may be designated as the Lower coal group. Occupying the zone next to the margin of the basin, it is sometimes,

as on the Kanawha above G1iwrU%t(m expanded over a wide area by broad undulations of the strata, and sometimes, as along the western flank of Laurel Hill, made to disappear at no great distance within the basin by the uninterrupted and somewhat rapid dip of the strata towards the northwest. The rooks comprehended in this group, with the exception of the shales and slates immediately asso- ciated with the coal seams, are, for the most part, coarse micaceous sandstones of a grey and light brownish colour, composing thick and massive hiyers, but little blended with softer shaly strata — with these are associated beds of limestone and the most important seams of iron ore met with in the coal measures.

Next above, we have a series of strata compridng reddish and bluish shales and slates, and grey, bluish and brown micaceous sand- stones, destitute of coal, or containing very tbin seams of local ex- tent. Beds of limestone, sometimes numerous and important, are also included in this group, and the black flint described in my re- port of last year as marking tbe upper boundary of the lower coal series on the Great Kanawha, is found towards its base. This may be called the Lower shale and sandstone group.

Still higher in the series, and occupying a zone still more re- moved from the margin of the basin, we have a group consisting of grey, brownish and greenish micaceous sandstones, reddish and greenish shales, and beds of limestone, in some districts of great thickness, together with several seams of coal, and more especially the eat seam which shows itself so extensively in the neighbourhood of PUtshurg Wheeling UnionUyamy Morgantoum Clarksburg Po- cotalico creek and other points in our coal region hereafter to be noticed.

To this series of strata we may give the name of the Upper coal group. Resting upon this we find an extensive series of rocks con- sisting of grey micaceous and felspathic sandstones, together with reddish ana greenish shales, more or less calcareous, and containing occasionally thin beds of limestone, but entirely aestitute of coal. This overspreading the central portions of the basin, comprises the highest strata of our great western coal measures, and may be termed the Upper shale and sandstone group.

Directing our observations to the systematic tracing of these several groups, with the view of defining, as nearly as practicable, the zones of surface over which they are spread out, and pursuing, from point to point, the more important seams of coal or strata of limestone, or other valuable materials met with in the respective groups, our operations during the past season, conducted by means of sections and longitudinal tracings were exte;ided over a wide area, portions of which had not been hitherto explored, comprising chiefly the following districts :

First. — The valley of the Great Kanawha, from the falls to Point Pleasant, with a portion of the region lying towards the southwest as far as the valley of Big Sandy.

Second. — The valley of the Little Kanawha, from the neighbour- hood of Bulltown to Parhersburg on the Ohio.

Third. — large portion of the regiou lying between the Little Kanawha and the Pennsylvania line, including the valley of the Mo> nongalia as high np as the neighhoarliood of Clarlcthurg,

Fourth, — The valley of the Ohio river from the northern ex- tremity of the state to the mouth of Big Saudy at the Kentucky line.

In t)ie northwestern district, as well as the valley of the Ohio and Great Kanawha rivers, our observations, as far as they were extended, were in general carried on with all the minuteness requi- site for the economical and scientific purposes of the survey ; bnt in the vuUey of the Little Kanawha, and the neighbouring regions on both sides, and in the tract lying between the Great Kanawha and Bandy, they were of a cursory or preliminary nature, being designed as a basis for the more thorough exploration of the ensuing season.

Dispensing with a detailed account of the various results of our investigations iu these several quarters of the great coal region, I shall confine myself to a brief description of the several strata com- prised in the three lower and more important of the groups above defined, in the order in which they occur.

First. — In a section extending from the commencement of the coal measures on the west side of Laurel Hill in a northwestwardly direction to the lower strata of the upper group ; and

Secondly. — In a section along the Ohio river from the northern extremity of Brooke county, the most northern point of the state, to the mouth of Big Sandy river at the Kentucky line.

Section II.

Strata comprised in the Three Lower Groups as displayed in a Sec- tion across the Monongalia Valley.

The following section, exhibiting in detail the various beds of rock and coal seams, included in the three lower groups above described, comprises the results of a continuous series of observations, com- mencing at the western base of Laurel Hill, following the course of Deckers creek to its mouth, thence pursuing the Monongalia river to the mouth of Scott's run, and continuing up the run to the ter- mination of the section.

As remarked in my report of last year, the anticlinal arrange- ment of the rocks in Laurel Hill brings to view, towards its top, and in the deep channels of the streams by which it is intersected, rooks subjacent in geological order to the lowest of the coal meas- ures, and appertaining to formations XI. and XII. of the Appalachi- an series. Along the natural section formed by Decker's creek in its passage through the mountain, the broad arch of these rocks may be distinctly traced, presenting near the centre the sandstones And limestones of XL, and towards the flanks of the ridges, the sandstones and conglomerates of XII.

Omitting for the present, any notice of the former, of which as occurring in this and the parallel axes towards the east, some do-

(

tails were presented in my last report, I will commence the account of the section now proposed to be described with formation XII.

Fobmation Xii,

This consists of a coarse siliceous sandstone, parts of which are conglomeritic, the pebbles being small and not numerous. It is of a grej and greyish white colour, is compact and not easily broken, and contains some felspathic saod.

This rock forms the superior part of the Laurel Hill axis, and in the line of the present section, is folded entirely over the mountain, dippearing below the bed of the creek on the eastern side, a little above the falls, and on the western a little below Goosemans bridge. At the falls it is well exposed, dipping towards the south- east, and forming a natural dam, which causes still water in the nar- row channel for some distance above, and it is also seen rising in heavy ledges along the flank of the mountain, to a considerable height above the stream. Here, and lower down the creek huge fragments of the rock are crowded together in its channel, obstruct- ing the flow of the stream, and almost concealing it from view. Some of these masses, which have tumbled down from their posi- tion in the great arch above, have the dimensions of a small house. At its western exposure, in the neighbourhood of Ooa8eman\ it is scarcely necessary to say that its dip is towards the northwest, and that its western or upper surface marks the commencement of the series of strata already designated as the lower coal group, to the detailed description of which, and the succeeding groups comprised in the present section I now proceed.

LOWES COAL OBOrP, OR FORMATION XHI.

No. 1.

ShaU.— Colour yellowish grey and dun, argillaceous, grain gener- ally fine, structure laminated. On exposure to the atmosphere, it disintegrates into clay. Near the bottom of this stratum is an ir- regular band of iron ore, sometimes forming a continuous layer, but occurring in the form of nodular masses, varying from two to twelve inches in diameter. It is an imp are proto-carbonate of iron, covered with layers of hydratic peroxide, produced by the decom- position of the carbonate. Its colour within, is grey and greyish don, on the outside yellow inh brown. Its grain is coarse, and frac- ture irregolar and sometimes earthy.

This ore is generally of inferior qnality, bnt has been extensively used at the neighbouring furnace. It has been discovered in iso- lated patches at numerous places on the slope and towards the sum- mit of the mountain, and has been mined at various points along its western base. It disappears below the bed of the creek, between Qoosemans bridge and the furnace, from a third or half mile be- low the former.

Its average thickness is estimated at 1 foot, that of the shales in which it is contained being about 6 to 10 feet.

No. 2.

Sandstone, — Colour very light grey ; grain fine, moderately com- pact; Btmcture slaty, separating in flags from one to six inches thick. It contains some imperfect specimens of vegetable fossils, mostly of the genns Lepidodendron. It is a very good firestone, and has been used for this purpose at the neighbouring furnace. Thickness about 4 feet.

No. 8.

On the line of section, the strata at this point are concealed, but from disclosures in other places, there is reason to believe that they consist principally, if not entirely, of shales containing some iron ore. Further examination will be required to determine their true nature and extent ; and such examination is rendered particu- larly important, by the consideration that this unobserved interval occupies a place in the series analogous to that in which some of the valuable beds of iron ore on Cheat river, resorted to by the Henry Clay and other furnaces are embraced.

No. 4.

Sandstone, — Colour greyish white, sometimes with a yellow tinge, due to oxide of iron. Grain coarse and siliceous ; contains some felspathic sand. Though of a variable character, this rock is usually compact and not easily wrought. It has been used for fur- nace hearths. It disappears beneath the creek- a little below the furnace. In some places, as in the vicinity of Cheat river, this rock so closely resembles formation XII. that the one might readily be mistaken for the other. Thickness from 25 to 80 feet.

No. 6.

Shale. — In part bituminous, imperfectly disclosed. Thought to contdn iron ore — yet to be examined. Thickness 15 to 20 feet

No. 6.

CoaL — In some places this seam consists entirely of the irised or peacock variety. At an opening on the side of Laurel Hill, south of Decker's creek, and about a mile southeast of the furnace, this character is very strikingly displayed. The coal is there quite fri- able, breaking into small irregular fragments ; its quality tolerably good. Thickness 18 inches to feet

No.r.

Flaggy Sandstones and Shales, — The strata are but partially dis- closed, but so far as observed, are of the above character. They are supposed to include iron ore. About two miles northeast of the furnace, a seam of ore has been slightly wrought, which is believed to lie among these rocks. This is to be further explored. "Whole thickness about 80 feet

Ko. 8. Coal, — A thin seam, aboat one foot thick.

No. 9.

Flaggy Sandstones and Shales. — Much coDcealed by slides, bat towards the upper part containing nodaks of hydrated peroxide of iron, to what extent remains to be determined. Ihickness about 40 feet.

No. 10.

Limestone, — Colour variable, blue, grey and dun. Some portions yellowish and ferruginous, with small cavities containing yellow ochre. It is a compact rock, of a fine grain and conchoidal frac- ture. For a few inches near its upper surface, it is yellow, and so highly ferruginous, as in some places to constitute a calcareous iron ore. Occasionally a seam of shale, about a foot thick, is found rest- ing upon thi, and above the shale another bed of limestone about a foot thick. This rock sinks below the creek at a point about tiiree fourths of a mile below the furnace. It is likewise met with on Aaron's creek, a tributary of Deckers, at a locality which has been examined. It is generally of good quality, and has been found valuable as a source of lime and as a flux ; for which latter purpose, it has been used at the furnace. Thickness about 8 to 4 feet.

. No. 11.

Shale. — Colonr dun and grey, or bluish grey; argillaceous; grain fine; structure lamellar. This stratum contains nodular masses of iron ore, consisting of proto-carbonate of iron within, and concentric layers of hydrated peroxide on the outside. It is of good quality, but in too small quantity to be of much value. Thick- ness 8 to 10 feet.

No. 12.

Sandstone. — Colour grey; micaceous; grain fine, rather com- pact ; quarries into flags. Thickness 5 feet.

No. 13.

Shale. — Colour dark blue; argillaceous; grain fine; structure laminated.

The lower part of this stratum includes a layer of nodules of iron ore, varying in size from a small pebble to more than a foot in diameter. It is a rich ore, consisting of the proto-carbonate, coated with hydrated peroxide, and was the material chiefly used at the furnace. For its composition, the reader is referred to my report of last yea pages 165, 166, 404, Nos. 14 and 16. It was mined on the side of Laurel Hill, in a southeasterly direction from the furnace. The average thickness of the band of ore is from 6 to 10 inches, that of the shales from 6 to 8 feet.

No. 14.

CaaL — Of moderately good qaalitj. Disclosed on Aarons and Deckers creeks. Thickness 1 to 2 feet.

No. 15.

Shale, — Argillaceous ; colour bluish and dun ; grain fine ; struc- ture laminated ; contains a few scattered nodules of iron ore of len- ticular form. Thickness 12 feet

Coal, — Friable, having a tendency to break into small rhombic pieces. Parts of this bed are rendered impure by the presence of sulphuret of iron, but towards the centre it is remarkably free from that mineral, and is hence regarded as of superior value for smithes purposes. It dips below the bed of Deckers creek about one mile below the furnace, and has been wrought at several places in the valley of the creek and on its tributaries. It has also been mined in the bed of the run, about three fourths of a mile north of Goose- mans bridge, and on a stream about the same distance southeast of the furnace, as well as on the main creek at about the same distance below the furnace. It shews itself in the bed of Aaron's creek about two miles from its mouth, and traced in a southwesterly di- rection, crosses Booth's, Thom's, White Day, &c. creeks. Thickness 8i to 4 feet.

No. 16.

Shale. — The lower part of this stratum, resting upon the coal seam above described, (15,) is often black and bituminous, and where disclosed on the run which empties into the creek near the furnace is very compact, has a conchoidal fracture, and is sometimes irised, bearing a strong resemblance to cannel coal. It is here some 10 or 12 feet thick.

The upper part is argillaceous ; colour greyish or dun ; structure laminated. This, at the locality above referred to, is about 12 feet thick, but at other places much thicker. Aggregate thickness 80 to 40 feet.

No. 17.

Coal. — A thin seam, which dips below the bed of Decker's creek, a little above the old forge. Thickness about 1 foot. Above this coal is a bed of shale. Thickness 5 to 6 feet

No. 18.

Sandstone, — Siliceous, containing some Felspathic sand; colour light grey ; grain co&rse, rather compact, but becoming less so as the bed is traced further towards the west from Laurel Hill. This rock admits of being quarried in layers of from a few inches to sev- eral feet in thickness.

The lower part of this stratum descends to the bed of Deck- er's creek, near the old forge, but owing to the diminishing steep- ness of the dip in oing towards the west, together with the rapid descent of the creek in the same direction, the upper part of the

Btratam continaes aboye the bed of the stream to MorgantowA where it is exposed in the bed and on the banks of the creek near its month in a thickness of from 20 to 80 feet. A little below Mor- gantaton it sinks below the bed of the Monongalia river.

Tracing this important stratum along the Monongalia above MargantawTiy it is seen gradually rising above the bed of the river forming a heavy ledge, partially concealed along the river hills, and at the distance of abont one mile above the town its elevation is such as to bring to view the underlying strata as far down as the coal seam No. 16, above described, which is here found in the bed of the river, and was formerly wrought to supply the town before the main seam of the upper coal gronp was discovered high up in the hills.

On Booths creek, about one third of a mile from the river, this stratum is seen forming a precipitous ledge some 60 or 70 feet high, known by the name of the Raven rocks."

Here the rock is less compact than near the mountain, disinte- grating by exposure, and, as is common among the sandstones of the coal measures, presenting cavities of various shapes and sizes upon its weathered surface, produced by the removal of the more finable portions of the mass.

This stratum is also disclosed with the same general characters, on Cheat river, White Day creek, Prickets creek, &c. dec. In some places, it forms a good building material, and has been used in con- structing the abutments of the bridge recently built over Deckers creek at Morgcmtown,

This is the highest stratum of tlie lower coal group, and its up- per surface forms the floor upon which the beds of the next superi- or group repose, to wit : the

Loweb Bhale And Sandstone Oroup, Ob Fobmatton Ziv.

This series of beds, included between the lower and upper coal gronps, composed principally of shales, but including some beds of sandstone and thin seams of coal, rarely of any workable extent, comprises the following strata :

No. 1.

Shale, — Argillaceous; colour variepjated brown and red; grain fine ; general structure laminated. Near its lower part, this stra- tum contains an irregular band of iron ore, from 6 to 8 inches thick. Like the ore No. 6, preceding, it is a proto-carbonnte, covered with a coating of hydrated peroxide. It is of a grey colour, coarse grained, and rough irregular fracture. Where mined near the site of the old forge, it is quite impure, nor is it likely to prove of much ynlne at other points, though in mixture with the ores of better quality, it was used at the furnace. At the forge it is from 40 to 60 feet above the bod of the creek, and continues in view to Mar- ganUnBUj sinking beneath the Monongalia a short distance below the town. Thickness of the shale 10 feet

No. 2.

Sanditone. — Micaceonfl; colour grey; grain rather coarse, but variable; structure tending to slaty. This bed varies greatly in thickness at different points, sometimes thinning out or passing into shale. Near the old forge it is twenty feet, at MorntiftDn madt less, and at some places assumes the character of merely a ahalj' sandstone. Thickness 20 feet.

No. 8.

Shales, — Argillaceous ; variegated ; colour brown, olive, dun and reddish ; structure laminated. An irregular seam of iron ore oc- curs towards the bottom of this stratum, of which some use was made at the furnace. Though concealed by the filling up of the pita, the seam as formerly wrought is known to have an average thickness of about six inches and to be of moderately good quality. It is occasionaUy calcareous. A few feet above this occurs an irreg- ular course of nodules of sufficient thickness in some places to have been found valuable. Both this and the other seam, however, are very variable as to quantity, not unfrequently thinning out entirely.

The upper part of this stratum sometimes includes a little bitu- minous shale, and probably very thin local patches of coaL Thick- ness about 20 feet.

No. 4.

LimeBtone, — Oolonr dark blue or blnisb black ; grain moderately fine; fracture sometimes conchoidaL sometimes irregular. This stratum furnishes a lime which, according to my experiments, is ca- pable of setting under water with great promptness forming a very hard mass. For the details of its composition see the report of la year, page 161 (899). Localities Rogers* mill and the ravine near Morgantown,

No. 5.

Shales, — Argillaceous ; variegated ; colours brown, dun and red- dish; grain generally fine; structure laminated; sometimes oon- taiuing nodules composed of calcareous and ferruginous matter blended. These shales are in many places partially concealed. Where observed in the raviue at Morgantown and the vaUey of Deckers creek, their thickness varies from about 35 to 50 feet

No. 6.

Limeetone, — This is the position of a thin band of limestone not disclosed in the ravine at MorganUnon or on Decker's creek, but which occurs on Aaron's creek about a mile from its mouth. It has been used for burning into lime. It is ferruginous, dark coloured and compact, and where seen has a thickness of about 10 inches.

No. r.

Shale. — Argillaceous ; colour grey or dun ; structure laminated. Where observed on this section in the ravine at Morgantown it is

partially oonoealed, bat as well as ooald be determined its thiokness u 10 feet.

No. 8.

Limestone. — Oolonr yellow ; very ferrnginous ; exfoliates on ez- posore to the atmosphere ; grain moderately fine ; fracture earthy. At the place of observation in the section it is qnite impure, though it efferyesoes briskly with acids. Thiokness 8 feet.

No. 9.

SKdUe, — Argillaceous ; variegated ; colours brown, dun and red- dish ; structure laminated. This stratum contains some calcareous nodules, imperfectly disclosed in the ravine at MorganUmn, Esti- mated tiiickness 80 feet.

No. 10.

Coal. — This is a thin seam of Inferior quality, sometimes passing into bituminous shales. It is exposed on a run about two miles from the mouth of Decker's creek, but was not seen in the ravine at Morgantown, Thickness 1 to feet.

No. 11.

FoBaUiferom Shale, — Calcareous; sometimes passing into lime' Btone ; colour generally greyish and bluish, but sometimes nearly black; containing numerous fossil sheUs of various genera and species. This stratum may be seen at several places along Deck- er's creek from the mouth of the ravine at MorganUnDn nearly as high up the stream as the old forge. Estimated thickness about 8 feet.

No. 12,

Sandstone, — Colour dark brown, with a bluish green tint; grain fine; compact, tough; fracture irregular, very difficult to break. Thickness 5 feet.

No. 18.

Shales and Flaggy Sandstones, — Colour of former variegated, brown and reddbh : the latter are grey and micaceous. The shales contain some nodules of impure iron ore. These rocks being but imperfectly disclosed, cannot here be fully described. Thickness about 40 feet.

No. 14.

Coal, — This seam and the smaller one, No. 10, appear to attain greater importance along the line of the present section than at any other points in which the intermediate group has been examined. Indeen, in no other places have the strata of that group been found to include any seam of workable extent. The structure of this coal is slaty. It contains some sulphuret of iron, but may be considered of moderately good quality. On Deckers creek it has been wrought at several places as high up as the old forge, where it runs out on the tops of the hills. At one of these openings on the land of Mr.

Wellsy it is about three /eet thick, aod lies at a height of about 170 feet from the bed of the stream. At Morgantown its height aboTe the creek is nearly the same, its dip corresponding with the fall of the stream. It sinks below the bed of the Monongalia river, above the mouth of Scotts run, and about two miles below MorganUnm, Thickness 2i to 8 feet.

No. 16.

Shale, — Colour grej, sometimes bluish ; character varjiug at dif- ferent places. Thickness 10 to 15 feet.

No. 16.

Conglomerate, — This curious stratum composed of a mixture of fragments of limestone, iron ore and Quartzose sand and pebbles, varies greatly at different points, as well in thickness as in composi- tion. In some places the materials are fine, consisting chiefly of iron ore, and the stratum not more than three or four inches thick, in others they are much coarser, containing fragments six or eight inches in diameter, and the stratum is then enlarged to a thickness of four or five feet. The fragments, though sometimes angular, are in general rounded, and by this and their large size, indicate the continued and violent action of currents, probably of local extent, which preceded and attended their deposition, where they are now found. Thickness from 8 inches to 6 feet.

No. 17.

Sandstone, — Colour yellowish brown, sometimes grey; grain rather coarse. This rock contains some Mica and felspathic sand. It admits of being quarried in blocks from 6 inches to 8 feet thick, is well adapted for some architectural purposes, and has been thus employed at Morgantown. On our line of section it runs out, or has its eastern boundary in the hills, a little above the old forge, and continued in a northwestern direction, sinks below the bed of the Monongalia river, at or very near the mouth of Scott*s run. Thick- ness according to estimation at different points, 25 to 85 feet.

The strata included between the sandstone (17,) above described, and the base of the upper coal group, in other words, all the re- maining beds of the intermediate group of shales, sandstones, &c., I am now describing, are, to a great extent, concealed at Morgan- towny as well as in the river hills between that place and the month of Scotts run, where, as above mentioned, the last described rock, No. 17, is at or very near the level of the river bed. Quitting Deck- ers creek and the river, therefore, the section is continued by re- suming the enumeration of the rocks at the river level, at the mouth of this run, and describing the strata as they are disclosed in ascend- ing the stream in a northwestwardly direction.

No. 18.

Shale. — Colour brown, or olive brown, grain fine ; structure lam- inated. About three feet of the upper portion contains ealcareovt

nodulei. Thickness at the place of observatioo, inoath of Scotts run, estimated at 15 feet.

No. 19.

Limestone, — FerrogiDOUs ; weathered surfaces bright yellow ; ex- foliates on exposure to the atmosphere. In some places the inte- rior portion is of a light drab colour, and a compact fine grain. Thickness 8 to 4 feet

No. 20.

Shale, — Nearly all concealed, but giving indications that it con- tains a little coal or bituminous shale. Thickness 10 feet.

No. 21.

Limestone. — The lower part of this bed is of a grey colour, com- pact, fine grained, and has a conchoidal fracture ; the upper part is ferruginous, and exfoliates on exposure to the atmosphere ; weath- ered surface bright yellow ; interior compact, and of a bluish col- our. Whole thickness 8 feet.

Immediately upon this bed of limestone rests a band of shale. Thickness 1 foot.

No. 22.

Limestone. — Somewhat ferruginous; weathered surface yellow, but does not exfoliate. In the interior, colour bluish; compact; grain fine ; fracture conchoidal. Thickness 8 to 4 feet.

No. 23.

Sandstone, — Colour yellowish brown; grain coarse; compact. Thickness 1 foot.

No. 24.

Sandstone, — Micaceous; colour bluish grey; grain fine; struc- ture laminar ; in the lower part including a little shale. Thickness 2i feet.

No. 25.

Shaly Sandstone. — Colour bluish grey. This bed contains lentic- ular masses of iron ore, apparently the carbonate, of a bluish tinge, placed with their flattened sides parallel to the lines of lamination, varying from the size of a walnut to masses weighing several pounds. Thickness 4 feet.

No. 26.

Shale, — Colour bluish. The lower part of the bed is argilla- ceous, of a fine grain, and laminated structure ; the upper is some- what siliceoQS, of coarser grain, and verging to the character of a ahaly sandstone. Thickness 22 feet.

No. 27.

Limestone. — Colour bluish or dun, weathered surface yellow; grain fine ; fracture couchoidaL Thickness feet.

No. 28.

Sandstone, — Micaceoas ; colour blaish; grain fine; stmctnre laminar. The upper part of the bed is hard and compact; the lower much less so, and sometimes graduating into shalj sandstone. In some cases the lines of lamination are oblique to the plane of stratification, having an inclination towards the northwest. Thick- ness 10 feet.

Nos. 27 and 2S, together with 2 or 8 feet of the upper part of 26, form the falls of Scott's run. at Boyer's, about half a mile above its mouth. 24 and 5 are seen a little below the mill.

No. 20.

Sandstone. — Colour bluish ; weathered surface yellowish brown ; exfoliates on exposure to the atmosphere. This rock has been used for whetstones and is said to be of some value for this purpose. Lo- cality, Boyer's mill. Thickness 5 feet.

No. 80.

Shale, — Colour olive brown ; grain rather fine ; structure lami- nated. Locality Boyer's milL Thickness 4 feet.

Nos. 81 and 82.

Sandstone, — Micaceous ; grey, of fine grain, laminar ; unchanged by the weather. Thickness 7 inches.

Shale, — Mostly concealed. Thickness 8 feet.

No. 88.

Limestone, — Colour bluish, sometimes tinged with brownish red; weathered surface yellow; grain moderately fine; compact; fracture splintery. Locality near Boyer's mill. Thickness feet.

No. 84.

Shale, — Mostly concealed, containing some nodules of iron ore. Locality same as above. Thickness 7 feet.

No. 86.

Limestone, — Very impure; colour brown; compact; fracture irregular ; slightly micaceous. Locality same as above. Thickness 8 feet.

No. 86.

Shale, — Too much concealed to admit of being accurately de- scribed. Estimated thickness 10 feet.

No. 87.

Sandstone, — This stratum . presents great and rapid variations of character. It is micaceous, and contains some felspathic sand, and is generally of a light grey colour. In some places, it is compact

and rafficiently durable to be nsed for bailding; in others qnickly disintegrating on exposare to the atmosphere. (As disclosed on Scott's run it presents a striking illustration of the sudden changes of composition frequently occurring in the strata of the coal meas- ures.) A little below Tribbet's mill, it includes a thin stratum of limestone of sufficient purity to be burnt for lime, but by one of those sudden changes so fluently occurring in the strata of the coal measures, this calcareous band is seen as we descend the stream ]Mssing rapidly, though by insensible gradations, into a sandstone (into whicn in a distance of a few rods it is entirely transformed,) so that in the distance of a few rods the transformation is complete. This sandstone dips beneath the bed of Scott's run a little below Tribbet's miU, and about three fourths of a mile above the mouth of the run. Thickness 25 to 80 feet.

Nos. 88 and 89.

ShaU and Coal. — The former is imperfectly disclosed. Thick- ness 8 feet. The latter is of moderately good quality, and was wrought for domestic purposes before the discovery of the thick bed some feet above it Thickness about 2 feet.

No. 40.

Limestone. — Colour bluish black, caused by an admixture of bi- tuminous or carbonaceous matter. Structure rather slaty; grain moderately fine ; fracture earthy and irregular. Place of observa- tion one eighth of a mile above Tribbet's milL Thickness 2 feet.

No. 41.

Shale. — Somewhat micaceous; colour blue and grey; grain generally fine ; structure laminar. This bed contains some flattened nodules of proto-carbonate of iron, arranged parallel to the lamina- tion. It smks below the run about one mile from its mouth. Thickness 14 feet.

The stratum last described forms the highest of the series of beds intervening between the lower and the upper coal group, and thus completes what has been designated as the lower shale and sand- stone group.

On a review of this series the amount of calcareous rock in- cluded in it, as displayed in the present section, claims attention as one of its most important features. Eleven hands of limesUme are embraced in this intermediate group in the region now referred to, giving an aggregate thickness of feet of limestone. Most of these bands are ferruginous, and otherwise impure, but are yet generally capable of yielding a lime suited to agricultural and building pur- poses, and even some domestic uses, where the colour is unimpor- tant. Of the eminently hydraulic character of one of them, mention has already been made, and I may add that judging by the appear- ance of the rock of some of the other bands, it is probable that the experiments yet to be made, will show them to possess similar value In the production of a water cement.

Uppeb Goal Gbodp, Ob Fobmatiok Zy.

No. 1.

Coal. — Main Seam of the Upper Grovp, — Considered in regard to its thickness and the quality of the coal, as well as the eztendve area over which it is found, and the facility with which it can be mined and conveyed to market, this is unquestionably the most valuable seam in the coal measures, either in Virginia or FenmyU vania. By careful tracings conducted in both states, this seam, ex- tensively exposed in the valley of the Monongalia from a point some distance above Clarhurg to the state line, has been sliewn to be identical with that which is so largely developed in the northern part of the same valley in its prolongation in PennsyhaniOy and which is disclosed so extensively in the vicinity of PitUhurg, It has been further proved, that continuing towards the west, this seam, coming to view on the Ohio river, constitutes the main coal stratum displayed in the hills at Wheeling and for many miles be- low ; and that still further down the river, it forms the Pomeroy or Carres run seam in Ohio and the corresponding bed on the Virginia side. "While prolonged in a southwesterly direction from the upper

Eort of the Monongalia valley, it crosses the Little Kanawha near eading creek; displays itself on the Great Kanawha below the mouth of Pocotalico, and on this latter stream, and is continued to the Big Sandy on the Kentucky line.

On the line of the present section, the most eastern outcrop of this seam is about a mile and a half southeastward of Morgantoun where it lies at a height of between 400 and 500 feet above the Monongalia river. Dipping very gently towards the northwest, its height at Morgantown is about 400 feet, and at the mouth of Scotts run, three miles further towards the northwest, is reduced to about 170 feet, making an inclination of about 75 feet to the mile. It sinks below the bed of Scotts run about one mile above its mouth, with a dip which there is reason to believe is steeper than from Morgantown to that point.

In ear Morgantown the thickness of the seam varies from to 8 feet. Between this place and the mouth of Scotts run, the hills on the east side have not sufficient height to include the coal, but those on the opposite side contain it at GrantilUy where it has been opened, as well as at otlir points.

As exposed at Morgantown it is overlaid by a thin band of shale, upon which rests a stratum of sandstone about 80 feet in thickness. This rock is coarse, felspathic, and contains a few quartz pebbles. On the east side of the river, it serves as a good index to the posi- tion of the coal, but in a northwestwardly direction it thins out or changes its character ; and on Scotts run there is not a trace of the sandstone remaining.

At Boyere mine, near the mouth of 6cott*s run, the main coa of this seam attains the great expansion of nine and a half feet, and is accompanied by other layers as exhibited in the following meas- ured section, in the ascending order :

1st. MaiD coal seam, 9 feet 6 inches.

2d. Black bituminous shale, 1 foot.

8d. Coal, tolerably good, 1 foot.

4th. Bluish shale, . 1 foot 8 inches.

6ch. Coal, 8 inches.

6th. Thin band of bituminous shale.

No. 2.

Shale, — Argillaceous; partially concealed ; grain fine; structure laminar. Farts of this bea are bituminous Thickness 10 feet.

No. 8.

Limestone. — This is the first of a series of beds of limestone, which, associated with shales, sandstones, and seams of coal, are found extensively developed in this part of the state above the great coal stratum just described, and which, while they furnish a valua- ble resource to the agriculture and the arts of the region in which they occur, impart naturally an unusual degree of fertUity to its soil. Traced towards the southwest, they are seen gradually thinning away as we iascend the valley of the Monongalia. Though of very considerable thickness at Clarksburg and for some distance beyond, they are almost lost on reaching the Little Kanawha river, where their place is occupied by extensive beds of richly productive cal- careous shales. On the Great Kanawha they are reduced to a few layers of calcareous nodules included in the shales lying above the Pocotalico.seam of coal.

The limestone No. 8, as seen in the present section, has tlie fol- lowing characters : Colour, when freshly broken, bluish grey; grain fine; compact; fracture oonchoidal. It is subdivided into three principal layers, having an aggregate thickness of 12 feet. Place of observation about a quarter of a mile above the point where the main coal sinks below the bed of the run.

No. 4.

Coal and Shale, — In this interval the strata are very imperfectly revealed. The coal, disclosed at one place only on the section, is of pretty good quality, and has a thickness of from three to four feet.

The rest of the space is occupied by shale with perhaps a little limestone — making together a thickness of about 7 feet

No. 5.

Limestone, — In two layers. Lower layer, colour grey ; weathered surface yellow; compact; fracture irregular. This is an impure limestone. Upper layer, colour grey ; weathered surface compara- tively unchanged ; grain fine ; fracture conchoidal. This is purer. Aggregate thickness 6 feet 4 inches.

Kos. 6 And 7.

Limestone, — Between this and the preceding bed of limestone, the strata are concealed for about 3 feet. This limestone has the following characters: Coloar bluish grej; grain fine; compact; fracture conchoidal. Thickness 8 feet. Aggregate thickness 6 feetw

No. 8.

Zimeitone, — Colour dark blue, nearly black; grain moderately fine ; fracture irregular earthy; structure slaty; thickness about 18 inches. It is included between thin beds of shale, making the ag- gregate thickness 5 feet 18 (8? £d.) inches.

No. 9.

Sandstone, — Micaceous, grey and fine grained. Thickness about 4 feet

No. 10.

Limestone, — Colour light drab, some narts bluish; grain fine; compact; fracture conchoidal; weathered surface yellow. It oc- curs in layers of from 4 to 8 inches thickness. Thickness of the stratum 6 to 7 feet

Nos. 11 and 12.

Coal and Shale, — This seam, second only in importance, as dis- closed in the neighbourhood of our section, to the main seam (No. 1,) is here seen resting upon a bed of shale (No. 11,) imperfectly disclosed. The shale is about 5 feet in thickness.

The coal was seen on the line of section only at two localities, to wit: at Wade'Sj nearly two miles above the mouth of Scotts run, and on a branch of that stream on the right in ascending about half a mile from its confiuence with the main run. At Wade's it displays itself in ajine seam Jive and a half feet thieky at a height of about 10 feet above the bed of the run ; and dips below it a lit- tle further up and about two miles distant from the river. At the other locality it is found in the bed of the stream, where it has been slightly wrought for the use of the neighbourhood.

At both mines the coal is of very good quality, containing but little sulphnret of iron.

The eastern outcrop of this bed is somewhere about the mouth of Scotts run, in which vicinity the hills on the western side of the river are of suflSclent height to contain this and the other seams of the upper coal group thus far described. Thickness of shale 5 feet ; ooal 6 feet 6 inches.

No. 18,

Shales. — Argillaceous ; colour bluish and grey ; grain generally fine ; slightly micaceous ; structure laminar. In the layers resting immediately above the coal, a few very imperfect impressions of ferns are seen. Place of observation Waders ooal bank. Thickness 20 to 25 feet

No. 14.

ScmdsUme. — Micaceons ; colour light grey ; grain fine ; strao- tare laminar. Place of observation same as above. Thickness about 10 feet.

No. 15.

Shales. — Argillaceous ; colour brown and blue ; grain fine ; structure laminar. The lower part contains a few lenticular nod- ules of moderately good iron ore of the Tariety usually found in the coal measures; the upper includes embedded masses of lime- stone of irregular form from a few inches to more than a foot in diameter, and which at other points may coalesce into a regular stratum. Thickness 12 feet

No. 16.

Limestone, — Oolour grey ; grain moderately fine ; fraicture con- choidaL Approximate thickness 2 feet.

Nos. 17 and 18.

Limestone and Shale, — Immediately above the preceding bed of limestone, we find a stratum of shale but imperfectly disclosed, having a thickness of 2 feet.

The limestone has the following characters : Colour light grey ; weathered surface yellow ; grain fine ; compact; fracture somewhat irregular. Towards the bottom of the stratum, there occurs a layer of about 2 feet thick, containing fragments of another lime- stone of the same colour. This layer bears the appearance of a Mag- nesian limestone. The subordinate beds are at this point so imper- fectly disclosed as to render a minute description of them at present impracticable. But there is little doubt that the entire thickness of these beds may be safely estimated at 7 to 8 feet.

No. 19.

Shale and Shaly Sandstone, — Shale, colour blue; structure lam- inar; argillaceous sandstone, colour grey; grain fine; structure laminar ; micaceous. Thickness 10 to 12 feet.

No. 20.

Limestone, — Colour variable, grey, blue, and drab ; grain fine ; compact ; fracture irregular. This stratum, exposed in a thickness of about 5 feet, appears to be extended along the run but little above its bed, as far as JaehsonviUe. A short distance below tlie viUage this, or a limestone having the same characters, is exposed to a depth of 7 feet, and may be of still greater thickness, extend- ing beneath the bed of the stream. It is here of a light drab col- our, and a portion of it (as in No. 18,) contains small fragments of embedded limestone. Another portion presents the very peculiar aspect of the magnesian limestone which occurs at Wheeling above tiie main coal seam, and which was found by my experiments last

:pllr,

These knotta and dkes, though Dot nsaall; of great extent, are exceedinglj onuierouB in loanj parts of the tract, giving a rugged- Dess to tne surface which it wonid not otlierwise present. Where appearing in the form of trne dykes or walls of Trap, rising through the strata in a ncarlj vertical directicm, they ma; some- times be traced loagitndinallj for a distance of a few miles, and a: then seen to have directions, which, thongh by no r are generally towards the west of north. But few ii ever, occnr, of their being prolonged with sufficient distinctnesa to admit of determining their bearing in a satisfactory manner, and (for the most part) they present themselves as isolated knobs or short ridges, with no traceable connection on the snrface.

The modifying influences of these igneous rocks upon the ata- cent strata, eiempliBed in my report of last year, with reference to certain localities in the southern tract, are observable also in nn- merous places in the northern area, the strata in the immediate vi- cinity of the kDol>s or dykes of Trap, though but little disturbed in pKwition, displaying in such cases various remarkable changes as to textnre, colour and composition. In most cases, the uteration thus produced does not extend beyond a change of colour and in- creased hardoess and density of the modified mass, but at some lo- calities it is marked by the development with the sulntance of tlie altered rock of various crystalline minerals, among which Epidote of frequent occurrence, sometimes distributed through the mass, but more commonly collected in the form of oval or spherical ker- nels, like those of an Amygdaloid As locallr illustrating the order

of tie f the 1

iiddle secondary strata and the mode of c

brief descripti

Taking as our tir the road leading t breadth of upwar i ary and igneous ro I-

Immediately w<, I and which is comp sandstone of the in hard and soft and alternating with gr . Broad run. Mam sufficient firmness n accordingly been e land creek. Tlie g numerous other local mains of vegetable si as converted

!)lnces with green cnri nnle of ng thin films and di.'eminnted Broad 1

the stream obliquely, with a benri] of sixty degrees to WSW, rises like a great

I r r'i hi c marked ont by

' He to Leahurg comprismg a I we find the nuddle econd- n i e f Unwmg Buoceasion mil r de on whicli Dranttrtllf stands eous slates we meet will the rvA Inrr consisting of layers allernAtelj some conglomerate "" ' stnl san Istone and jp* ie ti-ds presontei" ir 1 ilitrtobe ui "

to Iwo ftft in Ihicknesa, and

pcl of bard Sandstone or Gnde. lu nidUi If

Bod on tbe w£tm aile it displaja the usual L

lorfono. Beyond this, iih some reJdish da: ,

sb tolonred ilaty sandstMie; and fll>out a mfle before r

Gooae creek, we coidd upon anolber range of tmb Mttmc,

wliich we are again presented ttitli tbe reddish and Eght e

ahales and eandstones. At Gc>06e creek, the (iTeen aoae it m-

peated, forming a broad iyVe running N. a little V. and amij cm>-

tieaJ, and in about a toarth of a mile fbrlber on we bare aaffco-

dfke of tbe same materia), about 20 yards in width, rioag tinftis

on the soDth aide of tlie road like a aolid wall. Betwec* tk

dykea last mentioned tbe sandstone gives striking evidenecatf

toralioD, presenting itself as a bard, compact, fine-grained n

mottled and grey aspect, at first view beario);

a (iruco stone. It also esbibite a jointed bItqi

that of tbe igneous masses in tbe neighboarhood. and d

its original airatification. Beyond this we bsve altered a

and shalos. with green alone, to Leahurg. 'Within the toVB If small range of green stone, and in various directions ia the ari- bonrhood arc atmndant eiposares of tbe conglomeralfc Tk Iiv rock is cbaractrized in this part of tlie tract, 1tma sn tloDed, by tlio large proportion of limestone pebbica ii mmma,w wnll as tbe nmnnnt of caleareons mnticr diffoaed tliiiii,fc Ar rial by which they are cemented togiber. At fa/. Shat. s gi lr of a mile from tlie town, in a MUthem diredloa. Il k rt in oorbonale of lime as to be qnarried und burnt a fMiiaiiiii tf. fording a lime well sniteil for building and iik'<"''v pwyMta.

Tokinc as uiioiljur iltastrative section, the line of iW toiiA> road I. '.'J- ooiirtbonso to AldU, i

mil' I' :uiiiu7 region abool funr i

wn: . ijie. ftod imniedialcl* eU

die-

year to f arnish a lime possessed of h jdraalic properties. [ Vide re- port of last year, page 152 (400).] Gbemical examinations now in progress will determine this point. Thickness 7 feet.

No. 21.

Shalej Flaggy Sandstone and 0 little Limeetane at bottom. These strata, including a thickness of from 90 to 100 feet, though partly oonoealed, and therefore incapable of being accurately de- Mribed at present, display the following general characters :

Firet — The strata resting immediately on No. 10 are chiefly shales. They are argillaceous, and of bluish and brown colours, and near the centre include a band of limestone about one foot thick. It is a bluish grey rock, of a fine grain and conchoidal frac- ture, and acquiring a yellow surface by weathering. Thickness of these strata 40 feet.

Second, — Immediately above the shales we find a stratum of sandstone, grey, micaceous, flaggy, and of moderately fine grain. Thickness about 15 feet.

Third, — Above this sandstone is a space occupied by soft flaggy sandstones very partially dbclosed. Thickness 35 feet.

No. 22.

Limestone. — In layers from 4 to 18 inches thick, presenting marked differences of character.

Lower portion, — Colour very light drab, nearly white; gnun fine ; fracture conchoidal ; contains specks of white calcareous spar. This is a very pure limestone, and having a texture admitting of a good polish, and being variegated by the included spar, would form a pretty marble.

Middle portion, — Colour light brown; grain rather fine; com- pact; fracture irregular. Of less purity than the preceding.

Upper portion. — Colour bluish, in some places very dark blue, or neariy black; grain moderately fine ; comnact; fracture irregu- lar. This rock is disposed to break in small rhombic masses, and is inferior in purity to the lower portion. Locality Scott's run, near it head, on the right of the road above Jacksonville, Aggregate thickness 5 feet.

No. 23.

Shale with hands of Flaggy Sandstone, — Shale, argillaceous; brown and sometimes blue. Sandstone, grey. Thickness from 20 to 25 feet.

No. 24.

ConL — This is the highest workable seam met with in the line of our section. Indeed, in no part of the great coal basin, either in our own state or in Pennsylvania or Ohio, has any large seam yet been discovered, occupying a higher place in the coal measures. Even this, over a large portion of the basin, is comparatively thin and unimportant, and appears to attain its greatest development

west of the Monongalia in the neighhonrhood pf oar line of section, and on the Ohio river at some points between Fishing creek and Middle island.

On onr present line it rnns out on the tops of the hills some two miles below Jaeksont>Ule and descending towards the west, shews itself in the bed of Scotts run, between a half and three fourths of a mile above that place. At the place of observation, a mine about half a mile above Jacksonvillej the following measurements were taken, in the ascending order :

1. Coal; main seam containing a considerable amount of sul- phuret of iron, but of prettj good quality, 5 feet

2. Bituminous shale ; black, laminated, 1 foot 4 inches. 8. Goal ; tolerably good, 1 foot.

4. Shale ; Argillaceous, bluish, 9 inches.

6. Coal ; tolerably good, 1 foot 5 inches.

6. Bituminous shale, 8 inches.

The shale, No. 6, forming the uppermost of these layers some- tiroes expands to a thickness of 15 or 20 feet, and iu this case mer- iting a special description, may be designated by

No. 25.

Shale. — Sometimes bituminous ; colours bluish black and bluish ; Argillaceous; grain fine; structure laminar. As just stated, this stratum varies in thickness from 8 inches to 20 feet.

No. 26.

Sandstone. — Colour generally grey; grain coarse and siliceous, but contains some felspathic sand. This stratum runs out towards the southeast on the tops of the hills between two and three miles below Jacksonville, It is the highest rock of the upper coal group on Scotts run, its upper surface being about on a level with the head of that stream, and it therefore terminates the series of the Deckers creek and Scotts run section. Above this are a few beds of sandstone and shale, together with one or more inconsiderable seams of coal, and perhaps a layer of limestone which should be added to our description to complete the section so as to compre- hend the whole of the upper coal group. These, however, are not disclosed along the line of observation which terminates at the dividing ridge between the waters of Scotts run and Dunkards creek.

From what has already been stated in regard to the mutability of the strata as prolonged from place to place, the above section cannot be looked upon as indicating exactly the thickness and char- acter of the different beds as displayed in a vertical section at any one locality. It will, however, Ornish a useful picture of the gen- eral features of the different groups of strata which usually preserve some predominant character over a wide area, and will suffice to exemplify the extraordinary mineral wealth through which it im- mediately passes, as well as of the fertile valley of the Monongalia in general.

The following brief snmmary of the more important contents of the upper coal gronp as disclosed along our section will serve to shew the great afflaence of this portion of the coal measures as re- gards those Talnable materials, coal and limestone, along the valley of the Monongalia:

Coal in the Upper Coal Group,

First or main seam. No. 1, 9 0

Second seam, No. 4, 8 6

Third " No. 11, 6 6

Fourth " No. 24, 7 0

25 0

Making a total thickness of workable coal in this group along the line of our section and the vicinity of 25 feet

Limestones in the Upper Coal Group,

First or lowest bed, No. 8,

Second " No. 5,

Third " No. 7,

Fourth No. 8,

Fifth " No. 10,

Sixth No. 16,

Seventh " No. 18,

Eighth " No. 20,

Ninth " No. 22,

50 10

Making a total thickness of limestone in this group, along the line of section, of 60 feet. Adding to these the 5 feet of coal and 24 feet of limestone in the lower shde and sandstone group, and the 0 feet of coal and 3 feet of limestone of the lower coal group, we have Jbr the whole extent of coal measures embraced in our section, a thick- ness of about forty feet of coal and seeenty feet of limesUme a result wliich, making all allowances for fluctuations in particular strata, is well calculated to shew, in a striking point, the ample natural re- sources of this highly favoured portion of our state.

Section III.

Strata Displayed On The Ohio River.

From the mouth of Little Beater Fiver in Pennsylvania, to the mouth of Big Sandy on the Eentuehy line.

The strata disclosed along this line of observation, embrace : 1. The lower coal group, with the exception of those beds

which lying near its base, have their outcrop further towards the

north, in Pennsylvania and Ohio,

reet.

InchM.

2. The lower shale and sandstone group.

8. The npper coal group.

4. llie upper shale and sandstone group, excepting those heds which the river hills are not high enough to contain.

At the northern extremity of our section, near the mouth of Lit- tle Beaver, the Ohio river flows in the inferior part of the lower coal group, the outcrop of which is further towards the north. Descending the river from this point to the mouth of Fishing creek, the dip of the rocks is towards the south.

Throughout this distance, the course of the stream deviates hut little to the west of south, while the principal diameter or axis of the great coal hasin, having a direction more nearly approaching to N£. and SW. is prolonged from its northwestern termination in Pennnfhania, in a direction lying to the east of this reach of the Ohio. The river is thus made to approach this central line as it descends towards Fishing creek, and is there near, hut a little west of the axis or centre of the hasin. Below this point, assuming a direction more tow-ards the west, it continues to now nearly paral- lel with the axis, though a little west, as far as the hend helow Mill creek in Jaekaon county. It now hy a sudden turn penetrates some distance into the western side of the hasin, and the rocks having a dip towards the axis, that is towards the southeast, the strata which, during its previous course, were hurled helow its hed, are now seen in succession emerging to the surface.

Resuming its southwesterly course at Eerrs run, and preserving that general direction as far as Guyandotte, it continues to expose nearly the same strata appertaining to the western side of the hasin throughout the whole distance. Then hending away to the west, it enters the lower coal group ahout three miles ahove the mouth of Big Sandy, on the southern boundary of Virginia whence, taking a northwesterly direction, it passes directly across the western side of the basin, and finally, a few miles above ForUmouth in Ohio passes beyond its margin.

It is obvious, from this sketch of the general directions of the Ohio, in its passage longitudinally through the basin, that it presents a line of observation of great interest, comprising nearly the whole of the strata of the coal measures. Our observations along this line having been chiefly directed to the examination of the three upper groups, are as yet too incomplete to admit of an accurate section, in detaiX of the beds appertaining to that portion of the lower group which lies within the limits of the state. I shall, therefore, in the following description, confine myself to a general account of the lower group, as disclosed near the northern extremity of the state, accompanied with the details of one of several approximate sec- tions which have been made in that region, as preliminary to further more minute investigation — after which I will proceed to the de- scription of a second and third, and a portion of the fourth groups.

Section IV.

Lower Coal Group,

As dUelosfd on the Ohio Fiver, near the Northern extremity of the

State.

A 8 already mentioned, the inferior members of this group ore not disclosed on the Ohio river, at the northern boundary of the state, their outcrop being north of this in Ohio and Pennsylvania,

The whole group sinks below the bed of the river, a little above SteubenvilU at a point which we have determined and laid down on a profile section of the strata of this region. Occupying the zone nearest the margin of the great coal basin of Virginia , Pennsyltania and Ohio this group extending from the state of Ohio into Brooke county Virginia, and Washington county Pennsylvania, stretches in a broad curve around the northern end of the basin, embracing the coal and iron region east of Pittsburg, and thence continues along the western flank of Laurel II ill, in a southwesterly direction into Virginia, crossing Cheat river near Ice's ferry, Decker's creek a lit- tle above Morgantown, and the Valley river near the falls. Here the axis of Laurel Hill becomes so flattened near its southern ter- mination, that the group of strata we are describing extends over it unbroken. Continued in a southwesterly direction from this point, it crosses the Little Kanawha near Bulltown, the Big Kana- wha between Charleston and the falls, and the Big Sandy in a space extending some distance above and below the Burning spring.

This group being the great repository of the iron ores found so abundantly in the coal regions of Ohio and Pennsylvania, at no great distance from the Ohio river, will, on that account, as well as from its valuable beds of coal, demand future minute investigation. At present, as already intimated, I can only indicate the general order of stratification, as exhibited in preliminary sections — and for this purpose, I propose first to present a section taken near the month of Little Beaver in Pennsylvania; and secondly, two sec- tions taken in the vicinity of Wellsville, the one on the Ohio, and the other on the Virginia side of the river.

Section on the Ohio River, about one mile above the mouth of Little

Beaver,

This section, though not taken in Virginia, is here introduced as indicating the series of strata which would be found exposed at the northern extremity of Brooke county, the various beds at the two places differing in no important particulars.

No. 1. Sandstone. — Colour generally grey, grain moderately coarse ; quarries into blocks suitable for building purposes. Parts of this rock are so hard and compact, as to be wrought with great difficulty, and have hence been rejected in the construction of the locks on the Sandy and Beaver canaL Estimated thickness 25 feet.

No, 2. Shales. — Argillaceous, colour dark blue and black, some-

tiroes bituminous; grain generally fine; stractnre laminar. This Btratam in some places contains courses of nodular iron ore of the variety usually found in the coal measures. At the mouth of Little Beaver, these nodules vary from 8 to 8 inches in diameter. Thick- ness 30 to 40 feet.

No. 8. Coal, — Of tolerably good quality. Thickness from 12 to 22 inches.

No. 4. Shale. — Partially concealed. Tliickness 4 feet.

No. 5. Coal. — Of tolerably good quality. Thickness 2 to feet.

No. 6. Shale with nodules of iron ore. — Thickness 15 feet.

No. 7. Sandy Shale and Shaly Sandstone. — Colour generally grey. The inferior part of this bed, a little west of the line of sec- tion, passes into a coarse grained sandstone, which is probably the general character of this part of the stratum. Estimated thickness 40 feet.

No. 8. Shale. — Colour generally bluish, or dun ; argillaceous ; contains, towards the bottom, nodules of iron ore, though apparently not in large amount. Thickness 86 feet.

No. 9. Concealed Strata, — Thickness about 16 feet.

No. 10. Coal. — Quality pretty good, but contains some sulphu- ret of iron. This seam is in general overlaid immediately by the stratum of sandstone to be next mentioned, but in some a thin band of shale is interposed. At the place of section, the coal is about 5 feet thick, but traced under the sandstone a little towards tiie east, it rapidly diminishes to about 20 inches.

No. 11. Sandstone, — Colour rather variable, but generally light grey and brown ; grain in some places fine, containing felspathic sand and some mica, the latter producing a slaty cleavage. In other situations, the rock is more massive, and is composed of coarse sili- ceous sand, with some quartzose pebbles. It is, however, friable, and rapidly disintegrates by exposure to the atmosphere. Thick- ness estimated at 45 feet.

No. Shale, — Argillaceous; structure laminar ; contains some nodules of iron ore, and a thin seam of black bituminous shale. Thickness 6 feet.

No. 18. Sandstone. — Colour grey or brown ; grain moderately fine ; structure slaty ; the inferior part rather compact. Thickness 10 feet.

No. 14. Shales. — Argillaceous; colour dark blue; grain -fine; structure laminar. Portions of this heavy stratum are concealed by debris. Thickness 60 feet.

The shale No. 4, of this section, has a character that would seem to adapt it for the manufacture of pottery. At the place of section, it is about seventy feet above the river. Here the subja- cent strata are entirely concealed. But at the mouth of Little Beaver, they are disclosed nearly to the bed of the river, and there being no perceptible dip between the two points, the description of these beds in the section was made with reference to the latter place.

No. 8.

Skale. — Colonr very dark grey ; often sandy ; sometimes mica- ceous. Thickness 25 feet.

No. 9.

Sandsttme. — Colonr generally grey, bat in some places brownish from oxide of iron. Grain siliceoas and moderately coarse ; occa- sionally felspathic and micaceous. Thickness about 40 feet

Above this sandstone, at the place of our section, the strata are mostly concealed, until we reach the upper coal group which here caps the summits of the hills. Within this space, however, shales and sandstones were partially seen at several points, and limestone was met with near the top of the series.

The strata occupying this part of the group being well disclosed near the mouth of Wheeling creek, a little below the city of Whel- ing the section may be continued by annexing to the preceding col- umn the results obtained at the latter locality. Though not agree- ing in all details with the unfinished portion of the section near SteubenviUsy it will convey a correct impression of its more impor- tant features.

Oontinuation of the preceding section as disclosed near the mouth of Wheeling creek :

No. 10.

Shale, in thin layers intcrstratified with bands of sandstone. Shale argillaceous, olive coloured, and laminar; sandstone olive coloured. The lower surface of this stratum is about seven feet above the low water mark of the creek. Thickness 10 feet

No. 11. Shale, of a reddish or purple colour. Thickness 0 to 8 inches.

No. 12.

Limestone. — Colour grey; grain fine; compact Thickness 1 foot 6 inches.

No. 13.

Shale. — Colonr bluish ; indistinctly laminar. The upper portion is argillaceous, containing some impure calcareous nodules; the lower is inclined to be sandy. Thickness 17 feet

No. 14.

Sandstone. — This rock as quarried on the south side of Wheeling creek, near the city, presents much variety of character. The upper portion at the quarry where these observations were made, has a light drab colour and a fine grain, and contains felspathic sand and scales of Mica. The middle and lower portions consist of the same materials, but in different proportions, and therefore differ from the preceding in texture and colour. Colour yeUowish and bluish;

stractare sometimes finely laminated tLo lines of cleavage being formed by the scales of Mica.

Near the base of the stratum, some bands of the rock are calca- reoas, and are rendered so hard by the cementing power of the car- bonate of linie as to be unfit for use. In this calcareous portion are contained vegetable remains in an imperfectly carbonized state, some of them retaining their structure though converted into bi- tuminous coal. The whole stratum, as measured at the quariy, has a thickness of 26 feet.

No. 16.

Shale. — Colour bluish; sandy; passing into slaty sandstone. Thickness 11 feet.

No. 16.

ShaU, — Colour yellowish; arlaceous; laminar. This bed contains some nodules of iron ore. Thickness 8 feet.

This forms the highest stratum of the lower shale and sandstone group at Wheeling. Continued down the river, it disappears be- neath the bed of the Ohio a little above the mouth of Weegee creek.

Section VI. UPPER COAL GROUP ON THE OHIO RIVER.

The inferior members of this group, embracing all the most valu- able beds of coal and limestone, dip below the bed of the Ohio river, near the mouth of Sunfish creek. Still lower down the river, the dip becomes more gentle, and so continues to the mouth of Fishing creek. Passing this, the general course of the stream lies a little west of the centre of the basin, along the counties of Tyler Wood and Jaeieon, Throughout this distance, there being scarcely any dip in the direction of the river, the inferior members are retained beneath its bed ; but further down the course of the river, changing to the northwest, the whole series rises above the surface near Sliding hill, about three miles below Kerr's ran. Below this, they do not again sink below the surface, but form the mass of the strata in the hills as far down as the westerly bend in the river a few miles above Guyandotte. Below this, the whole group soon crops out on the river hills on the western side of the coal basin.

The following section, taken near Wheeling will indicate the nature and order of the strata constituting this group :

No. 1.

Main Coal Seam of the Upper Coal Orovp, the lowest stratum of this series. The quality of the coal is in general good, the sul- phnret of iron contained in it, not being in sufficient amount to in- jure it for ordinary purposes.

The following measurements, indicating the contents of the stratum, were made on Coal run, the stream uniting with Wheeling creek near the southeast corner of the city :

1. Main coal seam. Thickness 5 feet 8 inches.

2. Argillaceous shale. Thickness 1 foot.

8. Coal of pretty good quality. Thickness 2 feet.

No. 2.

Main LimesUme depoHt. — This groap of calcarcons rocks is here more fully developed than at any other point in the coal measures, and forms one of the most interesting features of the economical ge- ology of the region.

The subjoined measurements were also taken on Coal run :

1. Resting immediately upon the coal we have calcareous shale, succeeded by impure limestone. In some localities, the limestone itself is in contact with the coal, the shale being absent. Thickness 11 feet 4 inches.

2. LifMstone, — Colour very dark brown, inclining to blue ; com- pact. Thickness 9 feet 6 inches.

8. Calcareous Shale. — Colour bluish, embracing near the middle a few inches of very inferior bituminous coal, accompanied by a lit- tle bituminous shale. Thickness 6 feet.

4. Limestone, — Colour very dark bluish black; grain rather coarse; quite impure; exfoliates on exposure to the atmosphere. Thickness 4 feet 2 inches.

6. Limestone. — Colour grey; compact; consists of three layers with thin laminsB of argillaceous shale interposed between them. Thickness 6 feet 8 inches.

6. Calcareous Shale. — Rather dun coloured. Thickness 1 foot 6 inches.

7. Limestone. — Part of this is of a light drab colour; grain mod- erately fine ; fracture earthy. Probably hydraulic, and to be ex- amined with this view. Thickness 17 feet 6 inches.

The entire thickness of this group of limestones (No. 2,) is 53 feet 8 inches.

The remaining part of the present section is derived from ob- servations and measurements made at Wheeling hill, near the Na- tional road.

No. 8.

Shale, — Calcareous and bituminous, or carbonaceous; colour very dark grey, inclining to black; rather compact; effervesces briskly with acid; contains some beautiful impressions of fern. Thickness 1 foot.

No. 4.

Coal. — Bituminous, of moderately good quality. Thickness 4 to 6 inches.

No. 6.

Slaty or Shaly Sandstone.— CoIomlt grey. Thickness 8 to 10 feet.

No. 6.

STiale. — Argillaceous; colour bluish; contains some calcareouB nodules. Thickness 8 feet.

No. 7. SJuile, — Calcareous ; ooloor yellowish. Thickness 7 feet.

No. 8.

Coal, — Structure slaty, quality not good. Thickness 4 to 6 inches.

No. 9.

Shale, — Argillaceous, and sometimes sandy. Thickness 10 feet.

No. 10.

LnnssTONB. — Colour hloish ; composed of marly limestone, with thin bands of compact limestone alternately arranged. Thickness 50 feet.

No. 11.

ShdU. — Colour olive green. Thickness 8 feet 6 inches.

No. 12.

Limestone, — Colour light grey; grain moderately fine; rather npact. The upper pi Thickness 12 to 15 feet.

compact. The upper part sometimes passes into calcareous shale. "cki

No. 13.

ShaU, — Colour inclining to dun ; upper part argillaceous ; about one foot near the bottom is calcareous. Thickness 4 feet.

No. 14.

Limestone, — Marly ; colour yellowish ; lower part contains some compact bands. Thickness 17 feet.

No. 15.

Sandstone, — Sometimes shaly; colour olive; grain rather fine. Thickness 7 feet.

No. 16.

Shale, — Argillaceous and calcareous; effervesces freely with acid. Colour inclining to dun. Tliickness 9 to 10 feet.

No. 17.

Limestone, — Colour light grey; compact. Thickness 6 to 8 inches.

No. 18,

Shale, — Calcareous and argillaceous near the top; the lower portion of the stratum indistinctly exposed. Thickness 6 feet.

No. 19.

Limestone. — Colour greyish ; impure. Thickness 2 feet 6 inches.

No. 20. Argillaceous Shale, — Thickness 3 feet.

No. 21.

Shale. — CalcAreons ; lower portion includes some thin bands of limestone. Thickness 18 feet.

No. 22.

Limestone. — Dove colonred; grain fine; compact; consists of kyers from 8 to 16 inches thick, separated by lamimo of argiUa- cvous she. Thickness 10 feet.

No. 23. Shale. — Bitaminons ; colour nearly black. Thickness 1 foot

No. 24.

Coal, — Of moderately good Quality; imperfectly disclosed bt place of observation; used as fuel in vicinity; and said to have an average thickness of 2 feet 6 inches.

No. 26.

Limeetone.Ot pretty good quality; compact. Thickness 2 feet.

No. 26.

Sandstone. — Colour greyish, and sometimes tinged with oxide of iron ; occasionally coarse and felspathic ; passing into slaty sand- stone and more rarely into sandy shale. By estimation thickness 40 feet

No. 27.

Shales and Limestone Bands. — Partially concealed. Thickness 40 feet

No. 28.

Coal. — Opened in the vicinity ; but only partially disclosed at the place of observation. Thickness 8 feet.

No. 29.

Shales and Sandstones. — Towards the top the sandstones pre- dominate and are felspathic ; but beneath we meet with shales to- gether with thin bands of limestone. These strata extend to the summit of the hill, at the place of observation, viz : on the farm of Mr. Nichols. Thickness 80 to 90 feet.

The above series of strata* embrace all the beds of the upper coal group. A glance at the detiuls as here given, will be sufficient to indicate the immense economical valne of this group in the am- ple development which it attains on the Ohio in the vicinity of Wheeling. Leaving out of consideration the numerous thin bands of limestone associated with some of the strata of shale, the aggre- gate thickness of limestone here disclosed in the upper coal group is not less than one hundred and fifty feet. Of this, much is of a quality suited for the manufacture of lime for architectural pur-

poseS) and nearly all is capable of being made available in agricnl- tare. And it may be added that some bands are likely to proye valaable as a source of hydraulic lime.

The great economical importance of the main coal seam as well as the smaller beds above noticed, must be felt by all who are inter- ested in the progress of this enterprising and prospering portion of the state.

The following observations will serve to illustrate the position and character of the main coal seam, No. 1, of the preceding sec- tion, as disclosed at varions points along the Ohio river. Cropping out on the hUls near SteubenviUe at a height of between three and foar hundred feet above low water mark, its southeasterly dip car- ries it below the bed of the river a little above the mouth of Wee- gee. Between these points it has been wrought in numerous places on both sides of the river, displaying a thickness varying from four and a half to five and a half feet.

Below the month of Weegee, the course of the river being a lit tie east of south, the coal continues to sink still deeper below the bed of the river, as far as the mouth of Grave creek, where it lies at from 60 to 100 feet below the surface. Here, the river turning towiurds the northwest, and the dip being towards southeast, the coal approaches the surface, and is seen at the mouth of Pipe creek a few feet above low water mark. But below the mouth of Pipe creek, the river resumes its general direction and the coal again sinks beneath the surface. From this point downwards it contin- ues below the bed of the Ohio, at no place probably at a greater depth than 250 feet, to Sliding hill about three miles below Eerr*s run. At the base of this hill on the Virginia side it has been wrought at low water mark.

Between Sliding hill and Pomeroys landing, the coal has not been opened on the Virginia side on account of the low bottoms which intervene between the hills and the river, but on the opposite side it has been mined in numerous places. In Ohio at Kerrs run and Pomeroy's landing, it has been wrought extensively for exportation, more than one million of bushels being annually sent from these mines to Oineinnati. Here the average thickness of the seam is something short of five feet.

On the Virginia side it has been opened in but few places, though it is easily accessible throughout a distance of from six to eight miles below Pomeroys landing, after which the hills again recede from the river. As, however, the strata dip towards the southeast the mines admit less readily of being drained here than on the Ohio side.

At Berthesays bank, about one mile above the month of Lead- ing creek, where particular examination was made, the coal was found to lie at a height of about 60 feet above the river at low wa- ter, being of pretty good quality, and having a thickness of four feet four inches. Above the coal is a bed of arnllaceous shale, from four to five feet thick, containing between the lamime numerous vegetable impressions, which, however, are too imperfectly pre-

served to afford good specimens. Sarmonnting the shale is a heavy sandstone about fifty feet thick, of a greyish coloar, and composed of coarse siliceous sand with some scales of Mica, and some fel- spathic earth. Along this portion of the Ohio the sandstone here refeiTed to is a good index to the position of the coal, and is well nuirked by the mnral escarpment which it frequently forms in the hills above the coal. Ascending the river above Eerrs run, the lower surface of this sandstone sinks to the water level near Slid- ing hill, but the stratum does not wholly disappear until we proceed upwards a mile or two above Grahams Station. Hence for many miles along the river the coal can be reached by merely sinking through a part or the whole of this sandstone. Including this space, therefore, the Wheeling seam is accessible along this part of the Ohio on the Virginia side, for a distance of nearly fifteen miles.

On Ten Mile creek, below where the hills recede from the river, the coal has been opened on the land of Mr, Mitchell and is here said to be about six feet thick. Between this creek and Point Plecuant are wide bottoms extending back into plains or rather second and third terraces of nnnsual width, in the rear of which the hills are low and the strata much concealed. Along this part of the Ohio no thick beds of coal have been opened, although thin seams have been discovered in several places. The same is true of the hills below the month of the Kanawha. As the inclina- tion of the strata is such that this coal if continuous must lie in the river hills in this region, it is probable that the seam has greatly diminished in thickness, and is identical with a thin bed which has been opened at numerous localities of which the fol- lowing are some of the most important.

At Mr. Jame Swanks, near the lower end of Eight Mile island, is a seam about two feet in thickness, overlaid by a heavy bed of coarse sandstone, and lying at an elevation of about 180 feet above the river. A similar seam has also been discovered on the planta- tion of Mr. Charles Lewis, on Oldtown creek.

In the hill three fourths of a mile N£. of Point Pleasant, is a seam of good coal, feet thick, lying at an elevation of about 18 feet above high water mark (of 1832.)

A coal seam of from 2i to 8 feet thick has been partially wrought at several places between Point Pleasant and Gallipolis, on the Virginia as well as the Ohio side.

On the land of Gen. Steinbergen one and a fourth miles from the Ohio a seam has been opened having a thickness of between two and three feet. It is overlaid by a thin band of shale upon which rests a heavy coarse grained sandstone of a greyish colour, closely resembling that resting above the coal at Kerr's run. The coal lies at a height of about twenty-two feet above high water mark.

Below Steinhergens the course of the river is a little east of south for about twelve miles to the bend in the river below Eighteen Mile creek. In this distance, however, the dip of the rocks is very

Blight, ar.d the coal may generally be readily traced in the river hills. This is also the case with the superincnmbent sandstone, though somewhat variable in character and thickness. The coal has been disclosed by Mr. Menager between one and two miles below Grab creek. It is here separated near the centre by a band of shide, giv- ing the following section :

1. Coal, of good quality, 1 foot 10 inches.

2. Shale, 1 foot.

3. Coal, 1 foot 8 inches.

Descending the river, the coal continues to increase in thickness

so that about three miles or a little more below Menagers it is about four feet thick, and has been opened on the Ohio side of the river nt various places, on a level but little above the high water mark of 1882. On the Virginia side, the hills recede from the river, leaving wide intervening bottoms — and hence the seam has here not been explored.

Below Eighteen Mile creek the strata again rise in the hills, and though in some places pretty well disclosed, present no coal seam of important thickness. Thin bands, varying from eighteen inches to two feet, are found in the hills from Green bottom to Guyandotte — bat under such variable circumstances as to render their identifi- cation at distant points impossible.

In the river hill, four miles above Guyandotte is a thin coal seam, wliich, as exposed thence to Gvyandotte, appears to occupy the same geological position as the Pomeroy bed, and is, like that, overlaid by a coarse heavy sandstone.

Passing the mouth of Guyandotte river, the strata of the upper coal group soon crop out on the summits of the river hills, and as before mentioned, are succeeded, as we descend the river, by the lower shale and sandstone group, and then by the lower coal group, from the base of which the river emerges in the neighbourhood of Portsmouth in Ohio.

Chapter Viii.

Chemical Details,

Section I. Limestones from the Primary,

1. Limestone from Whitley's quarry, burned for lime. Colour bluiah grey; appearance vitrious; structure compact fine grained; fracture irregular ; traversed by thin veins of Calc spar.

Carbonate of lime,. 75.56

Carbonate of magnesia,. . 12.44

Alumina and oxide of iron, 0.40

Silica, 11.20

Water, 0.40

2. Limestone from Gibson's vein. Colour deep pink, with spots of grey white ; structure compact ; crystalline ; surface rough.

Oarbonate of lime, 77.48

Oarbonate of maesia, . ., 5.20

Alumina and oxide of iron, ' 1.20

Water, 0.40

Snioa, 15.72

8. Limestone from Qibson's quarry, soatb side of Rapidanne river.

Colour greyish blue, traversed by wbite veins ; structure compact ;

semi -crystalline ; vitreous appearance ; fracture irregular, rougn.

Carbonate of lime, 90.40

Carbonate of magnesia, 6.44

Alumina and oxide of iron, 0.52

Silica, 2.00

Water, 0.64

4. Limestone from Colby Cowherd miles from QordonmsiUe.

Colour deep blae ; surface of cleavage shining ; structure slaty ; fine

grained ; crystalline in places.

Carbonate of lime, 79.20

Carbonate of magnesia, trace.

Alumina and oxide of iron, 0.80

Silica, 19.60

Water, 0.40

6. Limestone from Rawlings' quarry, i mile SE. of meeting house, near Orange courthouse. Colour dark blue ; structure slaty ; crystalline in veins; fine grained compact; surface shining.

Carbonate of lime, 78.68

Carbonate of magnesia, 9.28

Alumina and oxide of iron, 0.80

Silica, 15.60

Water, 0.64

6. Limestone from Rapidanne river, 800 yards east of Gibsons vein; colour deep blue; aspect vitrious; structure compact; sur- face scaly ; angles acute.

Carbonate of lime, 75.44

Carbonate of magnesia, 5.04

Alumina and oxide of iron, 0.92

Silica, 17.92

Water, 0.68

7. Limestone from Todd's quarry, 5 miles from Gordonsville, near blacksmith shop. Colour beautiful pink, traversed by minute white veins ; structure compact, granular ; semi-crystalline ; frac- ture irregular, sharp angled.

Carbonate of lime, 51.72

Carbonate of magnesia, 42.72

Alumina and oxide of iron, 1 .28

Silica, 8.28

Water, 1.00

8. Limestone in thin layers in mica slate. Colour pink, rib* banded; veined with dark crystalline spar; structure granular.

Oarbonate of lime, 80.73

Carbonate of magnesia, 7.12

Alumina and oxide of iron, 0.44

SiUca, 11.04

Water, 0.68

Section II. Limestones of Formation 11.

1. Limestone from near Winchester on the turnpike west of the town. Colour bluish grey, spotted and streaked with dull grey ; structure hard and compact; fracture conchoidal ; surface smooth.

Carbonate of lime, 80.60

Carbonate of magnesia, 14.48

Alumina and oxide of iron, 1.68

Silica, 2.68

Water, 0.66

2. limestone fom Danlaps creek, near Sweet springs, Monroe count J. Colour bluish grey ; traversed by minute veins of white spar, structure compact ; surface rough and irregular.

Carbonate of lime, 86.52

Carbonate of magnesia, 9.52

Alumina and oxide of iron, 0.52

Silica, 2.96

Water, 0.48

3. Lime from Page county. Colour blue, with a dull ash lustre ; structure compact; fine grained; fracture irregular, with smooth surfaces, acute angled.

Carbonate of lime, 70.16

Carbonate of magnesia, 25.96

Alumina and oxide of iron, 1.60

Silica, 1.48

Water, 0.80

4. Limestone from near Harper's Ferry. Colour delicate flesh ; aspect semi-crystalline, structure slaty, compact, fine grained, sur- face irregular.

Carbonate of lime, 81.16

Carbonate of magnesia, 10.80

Alumina and oxide of iron, 0.52

SUica, 6.68

Water, 0.84

5. Limestone from Stage road, Shenandoah county. Colour blu- ish grey, aspect vitrious, compact, surface rather rough, angles sharp, splintery.

Carbonate of lime, 49.00

Carbonate of magnesia, 88.80

Alumina and oxide of iron, 0.84

Silica, 10.80

Water, 0.66

6. Limestone from Shenandoali river, Page county. Colour lead grey spotted with white ; structure crystalline ; fracture irregular, with rough surface ; compact.

Carbonate of lime, 47.48

Carbonate of magnesia, 45.80

Alumina and oxide of iron, 0.80

Silica, 5.40

Water, 0.56

7. Calcareous sandstone from the Woodstock road leading into Big Fort valley. Colour dark bluish grey, with a light yellow tinge veined with spar ; compact, irregular fracture, with minute scales of mica.

Carbonate of lime, 11.24

Carbonate of magnesia, 5.40

Alumina and oxido of iron, 9.86

Silica 73.20

Water, 0.80

8. Limestone from Page county. Colour bluish grey ; structure compact ; very fine grained ; fracture irregular, scaly.

Carbonate of lime, 60.92

Carbonate of magnesia, 36.48

Alumina and oxide of iron, 0.60

Silica, 1.44

Water, 0.56

9. Limestone from New Market, S/ienandoah county, near the junction of IT. and III. Colour greyish blue, traversed by veins of dark crystalline spar; structure compact; fine grained; fracture irregular ; surface waving.

Carbonate of lime, 81 .00

Carbonate of magnesia, 10.60

Alumina and oxide of iron, 0.28

Silica, 7.60

Water, 0.62

10. Limestone from two miles southwest of Harper's Ferry, Colour light grey, clouded with blue, dull pale streak; structure very compact, granular, semi-crystalline; fracture irregular, con- choidal.

Carbonate of lime, 53.88

Carbonate of magnesia. 43.40

Alumina and oxide of iron, 0.48

Silica, 1.68

Watr, 0.56

11. Limestone from Northwest turnpike, west from Winehegter. Colour dirty pale grey, clouded with blue; structure compact, granular, somewhat crystalline ; fracture irregular, rough, angular.

Carbonate of lime, 88.64

Carbonate of magnesia, 9.60

Alumina and oxide of iron, 0.12

Silica, 1.30

Water. 0.44

12. Limestone from Chestnut ridge, north fork of Holston river. Colour light grey, with a dull lustre; stractare compact; semi* crystalline; fracture irregular, angular.

Carbonate of lime, 60.9G

Carbonate of magnesia, 89.20

Alumina and oxide of iron, 0.80

Silica, 8.48

Water, 0.66

1 3. Limestone from east base of North mountain, Price's road. Colour rather dark grey, slightly tinged brown ; surface scaly, com- pact ; aspect vitrious.

Carbonate of lime, 52.20

Carbonate of magnesia, 88.40

Alumina and oxide of iron, 1.16

Silica, 7.44

Water, 0.80

14. Limestone from Page county. Colour blue, traversed by thin veins of spar ; appearance vitrious ; structure compact ; frac- ture concboidal.

Carbonate of lime, 69.60

Carbonate of magnesia, 27.04

Alumina and oxide of iron, 0.40

Silica, 2.60

Water, 0.36

15. Limestone from Northwest turnpike, 1 mile west of Winekes- ter. Colour grey blue; aspect vitrious; structure compact; semi- granular ; surface scaly ; fracture smooth, corners sharp.

Carbonate of lime, 67.24

Carbonate of magnesia, 28.80

Alumina and oxide of iron, 1.56

Silica, 11.68

Water, 0.72

16. Limestone from Stage road, Shenandoah county. Colour dark blue; contains crystalline spar; structure compact; fine grained ; fracture irregular.

Carbonate of lime, 75.96

Carbonate of magnesia, 9.12

Alumina and oxide of iron, 0.92

Silica, 18.60

Water, 0.40

Section IIL

Limestones of Formation XL

1. Limestone from Muddy creek mountain, GreenbrieT county. Colour pale lead, tinged with brown; spotted with ferruginous matter ; oolitic ; structure compact, semi-crystalline ; fracture con- cboidal.

Carbonate of lime, 88.64

Carbonate of magnesia, 9.60

Alumina and oxide of iron, 0.12

Silica, 1.20

Water, 0.44

2. Limestone from gap of Little North moimtain, between Crim- son snlphnr spring and Union. Colour grey blue, tinged witJi brown ; partially crystalline ; structure compact ; fracture irregular.

Carbonate, of lime, 78.48

Carbonate of magnesia, 9.20

Alumina and oxide of iron, -. 1.00

Silica, 10.80

Water, 0.62

Section IV.

Limestones of the Goal Measures.

1. Limestone from Ten Mile creek, KanawhOj one mile from its mouth; bed from eighteen to twenty-four inches in thickness. Colour pale lead, with a brown tinge ; structure moderately com- pact ; fine grained ; fracture splintery.

Carbonate of lime, 86.80

Carbonate of magnesia, trace.

Alumina and oxide of iron, 1.92

Silica, 10.88

Water, 0.60

2. Limestone from Two Mile creek, Kanawha lower stratum one to two feet in thickness. Colour lead brown, with a yellow tinge ; structure compact ; fine grained ; fracture scaly.

Carbonate of lime, 83.92

Carbonate of magnesia, 2.80

Alumina and oxide of iron, 0.80

Silica, 1.76

Water, 0.72

8. Limestone from Coal river at lowest falls, Kanawha, Colour dull brown, with a yellow tinge, spotted with Calc spar ; structure compact ; fine grained ; fracture irregularly conchoidal.

Carbonate of lime, 83.96

Carbonate of magnesia, 13.20

Alumina and oxide of iron, 0.48

Silica, 1.68

Water, 0.68

4. Limestone from Ten Mile creek, one mile from its mouth. Colour pale lead, tinged with yellow; structure compact; fine grained; fracture irregular.

Carbonate of lime, 84.40

Carbonate of magnesia, trace.

Alumina and oxide of iron, 1 .68

Silica, 13.28

Water, 0.64

5. Limestone from Little Buffaloe, Kdnatoha bed 18 inches in thickness. Colour pale yellowish red; structure compact; fine grained ; surface smooth ; fracture conchoidal.

Carbonate of lime, 72.52

Carbonate of magnesia, 6.80

Alumina and oxide of iron, 1.40

Silica,. 18.72

Water, t.. 0.56

6. Limestone from Eighteen Mile creek, KanawJui, three miles from its mouth at the saw mill. Colour pale lead, tinged with yel- low ; fine grained ; compact ; fracture irregalar ; comers sharp.

Carbonate of lime, 65.96

Carbonate of magnesia, 7.60

Alumina and oxide of iron, 8.68

Silica, 81.92

Water, 0.84

7. Limestone from Two Mile creek, KanawJia upper stratum, bed from 1 foot to 2 feet thick. Colour light yellow, with spots of dark coloured Calo spar; very fine grained; compact; surface waving.

Carbonate of lime, 96.20

Carbonate of magnesia trace.

Alumina and oxide of iron, 1.60

Silica, 1.60

Water, 0.60

8. Limestone from Tylers creek, Kanawha bed 1 foot thick. Colour yellowish light brown ; compact ; tine grained ; fracture ir- regular ; comers sharp.

Carbonate of lime, 76.80

Carbonate of magnesia, trace.

Alumina and oxide of iron, 5.20

Silica, 17.00

Water, 2.00

9. Limestone from Big Buffaloe, Kanavolia bed 2 feet thick. Colour fresh; fracture lead; aspect earthy; compact; rather fine grained.

Carbonate of lime, 73.44

Carbonate of magnesia, 6.82

Alumina and oxide of iron, 2.16

Silica, 18.48

Water, 0.60

10. Limestone from Crooked creek, Point Pleasant Mason county. Surface variegated ; curiously spotted with beautiful dark coloured spar ; fine crystallized ; compact.

Carbonate of lime, 79.84

Oarbonate of magnesia, 6.28

Alumina and oxide of iron, 3.62

Silica, 9.68

Water, 0.68

11. Limestone from Two Mile oreek, Kanawha county, upper Btratam one foot in thickness. Colour grey brown, with a tinge of yellow, spotted with white spar; compact; fine grained; surface waving.

Carbonate of lime, 89.72

Carbonate of magnesia, trace.

Aluminand oxide of iron, 2.00

Silica, Y.20

Water, 1.08

It should be remarked that most of the limestones of the coal measures exhibit traces of carbonaceous matter, which, however, is burned off in the kiln, while those which contain a considerable amount of oxide or carbonate of iron make a dark lime. In many cases they yield a lime which is hydraulic as in the instances men- tioned in my last report, as well as in others, now in course of ob- servation.

Section V.

CoaUfrom Formation XIIL

1. Coal from Jud>ge Summers' bank. Coal creek, Kanawha. Somewhat compact, cleaves into thin lamino, striated, cleavage sur- face has a charred appearance; afresh fracture, shining jet black.

Carbon, 66.55

Volatile matter, 41.85

Ash, 2.60

2. Coal from Judge Summen vein, Grand creek, Kanawha. Compact, fracture irregular,, surface smooth, jet black and irrides- cent, strisB indistinct.

Carbon, 62.75

Volatile matter, 48.20

Ash, 4.05

8. Coal from Wolf creek, mile above the Burning spring, Big Sandy. Laminated, surface brilliant shining jet black, easily frac- tured, and when broken, exhibiting an irregular pitted surface, striaa indistinct.

Carbon, 47.15

Volatile matter, 48.00

Ash, 4.86

4. Coal found in the bed of Big Coal river, 5 miles above the junction of the two branches, Mr, Jno, Lewis. Cleaves into lami- nsa, the surface of which is covered with films of charcoal, cross fracture jet black shining, irregular ; striae distinct.

Carbon, 50.20

Volatile matter, 47.10

Ash, 2.70

5. Coal from Mr. CartreWs property, Three Mile creek, Kanawha oonnty. Semi-compact, somewhat laminated ; fracture irregular ; snrface dull black, with spots of shining jet black.

Carbon, 46.96

Volatile matter, 60.80

Ash, 3.76

6. Coal from Friend Welsh db CoJ*s roines, Elk river, Kanmoha county. Massive, fracture irregular, lustre dull black, sometimes shining jet black; stnaa distinct.

Carbon, 64.90

Volatile matter, 89.90

Ash, 6.20

7. Coal from Mr, LawsorCs opening, Logan courthouse, 8 feet thick. Massive, cross fracture shining jet black, striss indistinct.

Carbon, 68.85

Volatile matter, 89.60

Ash, 2.16

8. Coal from Traa fork, Guyandotte, 6 feet thick. Massive, ten- dency to columnar structure, dull black irregular fracture.

Carbon, 66.60

Volatile matter, 42.00

Ash, 1.60

9. Coal from Pigeon creek. Big Sandy river. Shining jet black, surface of lamin charred, fracture irregular.

Carbon, 65.00

Volatile, 41.00

Ash, 4.00

Section VI.

Iron Ores from the Primary,

1. Iron ore from Ross furnace, Hopewell creek, hematitic brown oxide. Structure somewhat fibrous and cellular, interior of cells coated with a bluish crust; colour clove brown, lustre glimmering and resinous.

Composition in 100 parts.

Peroxide of iron, 81.11

Alumina, 0.28

Silica and insoluble matter, 6.54

Water, 11.10

Loss, 0.97

Per cent metallic iron, 56.77

2. Iron ore, from Yeatman's, Stonewall creek, composed of brown hematite and siliceous brown oxide. Structure externally hematitic, fibrous; internally amorplious, granular; colour blackish bro'n, lustre glimmering.

Composition in 100 ports.

Peroxide of iron, 76.00

Alumina, 0.50

Silica and insoluble matter, 18.00

Water, 10.00

Loss, 0.50 I

Per cent metallic iron, 58.20. ,

8. Iron ore from Elk creek, half a mile above mouth.

Structure amorphous, cellular; colour chestnut brown; general aspect earthy, in spots glimmering.

Composition in 100 parts.

Peroxide of iron, 84.00

Alumina, 0.85 '

Lime, mere tracu. I

Silica and insoluble matter, Y.60 i

Water, 7.10

Loss, 0.45

Per cent met. iron, 68.80.

4. Iron ore from Colonel Bancoeh*s farm, east side of Falling river.

Structure amorphous; compact; fine grained; fracture some- what conchoidal ; colour chestnut brown, without lustre.

Composition in 100 parts.

Peroxide of iron, 84.20

Alumina, 0.56

Lime, trace.

Silica and insoluble matter, 4.50

Water, 10.00

Loss, 0.74

Per cent. met. iron, 58.94.

5. Iron ore associated with Taloose slate, from bank six miles southwest of New Canton.

Structure massive, compact and siliceous ; colour clove brown ; surface presenting glimmering points of quartzose particles.

Composition in 100 parts.

Peroxide of iron, 64.95

Alumina, 2.65

Oxide of manganese, a trace.

Silica and insoluble matter, 28.80

Water, 10.00

Loss, 0.20

Per cent. met. iron, 45.49.

6. Iron ore from same locality as above.

Structure cellular; cells minute; colour light brown ochreous; contains small specks of Quartz.

Composition in 100 parts.

Peroxide of iron, 72.00

Alumina, 1.38

Silica and insoluble matter, 16.47

Oxide of manganese, a trace.

Water, 10.04

Per cent. met. iron, 60.40.

Skotion VII. Iron Ores from Formation I.

1. Honeycomb ore, Graham's bank, Reed creek, Wythe county. Structure somewhat cellular ; walls of cells compact and close

grained; aspect of surface eailhy, of interior slightly resinous; colour chestnut brown. Composition in 100 parts.

Peroxide of iron, 79.49

Alumina, 0.75

Silica and insoluble matter, 8.46

Water, 11.00

Loss, 0.30

Per cent. met. iron, 54.94.

2. Iron ore from Forrer's bank, Page county.

Structure cellular and hematitic, filled with reddish oxide, very tenacious and rough.

Composition in 100 parts.

Peroxide of iron, 79.74

Alumina, 0.76

Silica, 7.67

Water, 11.58

Loss, 0.26

Per cent. met. iron, 66.81.

3. Forrer's bank, Page county.

Structure hematitic, in slender stalactitic columns ; colour bluish black ; spans between the columns occupied by a rich orange red oxide ; lastre resinous and iridescent.

Composition in 100 parts.

Peroxide of iron, 74.66

Alumina, 4.60

Lime, trace.

Silica and insoluble matter, 6.80

Water, 16.00

Loss, 0.14

Per cent. met. iron, 62.19.

4. From shales of F.I, Augusta county.

Structure somewhat crystalline; hematitic, compact; colour dark chestnut brown.

Composition in 100 parts.

Peroxide of iron, 85.87

Alumina, trace.

Silica and insoluble matter, 2.60

Water, 10.90

Loss, 0.73

Per cent. met. iron, 60.10.

5. Iron ore from Poplar Camp famaoe, Wythe connty.

Structure irregular nodalar; oloee grained, somewhat cellular; oolour dull brown, without lustre, earthy.

Composition in 100 parts.

Peroxide of iron, 72.04

Alumina, 1.55

Silica and insoluble matter, 4.45

Water, 11.36

Loss, 0.61

Per cent met. iron, 50.42.

Seotioit Vin.

Iran Oreifi'Ofn Formation IL

1. Iron ore from Cedar Creek works, 2 miles from Ruuell court- bouse.

Structure hematitio, cellular ; brown black, interior of cells lined with a dull brown oxide.

Composition in 100 parts.

Peroxide of iron, 72.65

Alumina, 8.75

Peroxide manganese, trace.

Silica and insoluble matter, 11.50

Water, 12.00

Loss, 0.10

2. From near Miller's now Kenagay% iron furnace. Mossy creek, Aiffusta county. Structure cellular, celb ochreous, compact fine grained semi-crystalline; colour chestnut brown, bright.

Composition in 100 parts.

Per-oxide of iron, 81.00

Alumina, trace.

Silica and insoluble matter, 9.50

Water, 9.27

Loss, 0.28

Per cent metallic iron, 56.70.

8. Iron ore, from Silver creek, used at Kenagays- furnace. Struc- ture compact, fine grained, surface smooth ; colour dark reddish brown.

Composition in 100 parts.

Peroxide of iron, 82.00

Alumina, trace.

Silica and insoluble matter, 8.14

Water, 9.27

Loss, 0.59

Per cent, metallic iron, 57.40.

4. Iron ore from Wythe county, base of Iron mountain. Struc- ture cellular; oolour dark dull chestnut brown, semi-crystalline. Composition in 100 parts.

Peroxide of iron 92.00

Alumina, trace.

Silica and insoluble m&tter, 4.00

Water, 8.29

Loss, 0.71

Per cent, metallic iron, 64.40.

Section IX. Iron ores from Formation V.

1. Iron ore from Poor Valley ridge, near Cumberland gap. Structure slaty, laminated, fossiliierous. Colour rich brown, with a semi-metallic lustre, arising from the micaceous character of the fossil casts which cover the surface.

Composition in 100 parts.

Peroxide of iron, 76.60

Alumina, 7.60

Ox. manganese, trace.

Carbonate of lime, 1.00

Magnesia, trace.

Water, 8.00

Silica and insoluble matter, 11.80

Loss, 0.60

Per cent. met. iron, 58.55.

2. From the Bloomary, south of road on western side Capon mountain. Structure cellular, cells lined with hematite; colour dark chestnut brown.

Composition in 100 parts.

Peroxide of iron, 84.80

Alumina, trace.

Silica and insoluble matter, 8.50

Water, 11.12

Loss, 0.58

Per cent. met. iron, 59.86.

Section X.

Iron Ores from the Western Coal Measures.

1. Iron ore from Eelleys creek, interspersed in shales, Kanawha, Nodular iron ore ; structure nodular, compact, close grained ; col- our of the mass dull reddish grey, of crust reddish brown ; fracture somewhat conchoidal.

Composition in 100 parts.

Carbonate of iron, 82.55

Alumina, 1.00

Lime, trace.

Silica and insoluble matter, 12.05

Water, 8.50

Loss, 0.90

Per cent. met. iron, 89.85.

2. Iron ore on Hamilton Place, NickolM conntj, oocun on top of hill in rounded masses. Structure irregularly nodular ; texture brittle and somewhat close grained ; colour chestnut brown, with blackish spots of a dull, resinous lustre.

Peroxide of iron, 80.75

Alumina, 1.25

Silica and insoluble matter, 7.40

Water, 10.00

Loss, 0.60

Per cent. met. iron, 56.52.

8. Iron ore in the red shales, above the blue sandstone at Ked Ilouse shoals, Kanawha, Structure compact and somewhat slatj; close grained ; colour cinnamon brown, without lustre, except a few glimmering points.

Composition in 100 parts.

Peroxide of iron, 58.41

Alumina, 8.45

Silica and insoluble matter, 82.44

Water, 4.60

Loss, 0.20

4. Iron ore, found on dividing ridge between Eighteen Mile creek and Kanawha river, one mile from latter, back of Mr, Heneys Kanawha. Structure massive, close grained; fracture somewhat conchoidal ; colour dull brown, with glimmering micaceous points.

Composition in 100 parts.

Peroxide of iron, 83.00

Alumina, 5.45

Ox. manganese, 0.25

Silica and insoluble matter, 10.90

Loss, 0.40

Per cent, metallic iron, 58.10.

5. Iron ore from the Chesterfield coal basin. Structure massive, somewhat slaty; texture coarse; colour brownish black, with glim- mering quartzose points.

Composition in 100 parts.

Peroxide of iron, 66.00

Alumina, 7.10

Silica and insoluble matter, 14.30

Water, 12.50

Loss, 0.10

Per cent. met. iron, 46.20.

Seotion XI.

Coali of the Chesterfield Powhatan Goochland and Henrico Basins,

The following results have reference chiefly to a series of speci- mens collected at an early period of the survey, from working which in many cases have been discontinued. A still ampler suite

of all the coals of this region, collected more recently, and now under examination, will furnish an additional body of details, suffi- cient, when connected with those now given, to illustrate fully the chemical character and economical value of all the coal seams of this poi tion of the state.

CoaUfrtfm South Side of Jama JSiver,

1. Coal from Stonehenge. Colour of ash, light reddish.

Carbon, 68.70

Volatile matter, 36.50

Ash, 4.80

2. Coal from Engine shiuft. Maidenhead. Colour of ash, strong red.

Carbon, 68.97

Volatile matter, 82.83

Ash, 8.20

8. Coal from Engine shaft, worked by ffeth, PoWs dk Co, ; col- our of ash, reddish yeUow.

Carbon, 62.85

Volatile matter, 87.65

Ash, 2.80

4. Coal from Mills dk ReitTi Creek pit. Colour of ash, buff.

Carbon, 67.80

VolatUe matter, 88.60

Ash, 8.60

5. Coal from WiW$ pit. Colour of ash, light brown.

Carbon, 62.90

Volatile matter, 82.50

Ash, 4.60

6. Coal from Greenhole shaft. Colour of ash, light red.

Carbon, 67.88

Volatile matter, 80.17

Ash, 2.00

7. Coal from Col, Beth* deep shaft, where the explosion oc- curred. The seam is between thirty and forty feet in thickness. These specimens were selected for analysis, and gave the following re- sults:

Specimens from the bottom of the seam. Colour of ash, liglit- pinkish brown.

Carbon, 68.86

Volatile matter, 85.82

Ash, 10.82

Specimen from the middle of the seam. Colour of ash, light brownish yellow.

Carbon, 66.60

Volatile matter, 28.40

Ash, 5.10

Specimen from the top of the seam. Colour of ash, light pink, inclining a little to brown.

Carbon, 61.68

Volatile matter, 28.80

Ash, 9.62

8. Ooal from Powhatan pits, formerly worked by Copt, Finney. Ooloor of ash, pale baff.

Carbon, 69.87

Volatile matter, 82.88

Ash, 7.80

Coals from near the Appomattox River,

The snccessfol explorations of Mr, Cox on Winterpock creek, near the southern termination of the Chesterfield basin, have of late given great interest to this portion of the coal field. The qual- ity of the coal at Mr, Cox's opening, as indicated by analysis, and proved by its use in the grate, is sach as to ensure its extensive em- ployment, and combined with the favourable attitude of the seam, and its ample thickness and extent, cannot fail to confer much im- portance upon this part of the basin.

The following analysis will convey an idea of the composition of the coal. Additional chemical examinations are still required to give a fair average of the several varieties found in this portion of the field.

9. Coal from Mr, Cox's mine, Winterpock creek.

Carbon, 66.62

Volatile matter, 29.12

Ash, 6.36

Coals from North Side of James River,

10. Coal from Capt Thomas M. Randolphs, Colour of ash, light red.

Carbon, 66.16

Volatile matter, 80.50

Ash 8.35

11. Coal from Coalbrook dale. Second seam. Colour of ash, light grey.

Carbon, 66.48

Volatile matter, 29.00

Ash, 4.52

12. Coal from Anderson's pit. First seam in shaft where the upper seam only was wrought in 1836. Colour of ash, light grey.

Carbon, 66.78

Volatile matter,., 28.30

Ash, 4.92

13. Ooal from Bwrr*s pits. First seam. Colour of ash, fiiint rod.

Carbon, 70.80

Volatile matter, 24.00

Ash, 6.20

14. Coal from Jiirr'* piu. Second uam. Colonr of ash, strong red.

Carbon, 64,97

Volatile matter, 22.88

Ash, 22.20

15. Cool from Barr't pits. Third team. Colour of aah, light browD.

Carbon, 6S.G0

VolalUe matter, 34.70

Ash, 9.80

16. Ooal from Barr't pita. Fow team. Goloar of asb, stroog

Carbon, 66.07

Volatile matter, 21.83

Ash, : 22.60

17. Coal from Croueh't lower shaft. Upper Beam 110 feet be- neath snrfaoe.

Carbon, 64,60

Volatile matter, 30.00

Ash 6.40

18. Coal from Seott't pit, formerly Woodward't. Colour of ash, light grej.

CarlHin, 60.86

Volatile matter, 83.70

Ash 6.44

19. Coal from Waterloo shaft.

Carbon, 66,20

Volatile matter, 26.80

Asb, 18,00

SO. Coal fh>m the Deep ran pits.

Carbon, 89.84

Volatile matter, 26.16

Ash, 6.00

CoUfiom ChetterJUld. This curioQS material, oecnrrinjt in a verj beaTj bed at the east- ern margin of the basin, towards the river, has the aspect and com- poNUoD of a cool which lias been in great port deprived of its vola- tile ingredienta by heat, accompanied by such a pressure of the overlying strata as woold prevent the puffy cellalar teiture usaallj assumed by coke. Its geological position, and the probable agenciea to which it owes its present form, will claim a detailed illustration at a future time. For the present T may remark, that retaining all the carbon of the original coal, this material has great value as a combustible, yielding the intense and steady heat of anthracite, at the same time that, from its less compact teiture, it is more readily iKnited than coal of that description. The following is the oompo- ition of 100 grwns of the more compact variety :

Carbon, 80.80

Volatile matter, 8.9S

Aah, 9.73

E E P O R T

or THB PROGRESS Of

The Geological Survey

or

The State Of Virginia

FOB THE YEAR ISiX.

Officx of tbb Board of Pubuo Woskb, 80th Dtetmber, 1641.

Sib, I bare the bononr to transmit herewith the report of pro- fessor Rogers to the Board of public works, respecting the progress of the geological sorvej of the state under his direction during the past season.

It is no doubt in the recollection of the legislature, that the act authorizing the survey was repealed at their last session from and after the 1st January, 1842. The board respectfully represent, that by the operation of that act, there is, in their opinion, a strong prob- ability that the great benefits which were so confidently anticipated from the survey, will in a great measure be lost to our citizens. It is only the final comprehensive report, systematically arranged, and embodying the results of nearly seven years laborious investi- gation, which can display in a proper manner, the new, various and valuable developments made in regard to the geological structure of the state, its rich and inexhaustible mineral wealth, and its vast ag- ricultural resources. To enable him therefore to present such a report, to arrange the numerous mineral specimens, and to prepare the necessary drawings and maps, professor Rogers recommends that the services of his corps, as at present organized, be continued until the regular close of the geological year in April next, and that an additional appropriation of $2500 be made for the purposes above mentioned.

The reasons adduced by professor Rogers are in the view of the board so unanswerable, that they do not hesitate most respectfully to recommend the passage of an act in accordance with his sugges-

With the highest respect,

John Rutherfoobd, President of the Board of Public Works,

To the Honourable

2%e Speaker of the Home of DdegaUs.

Report.

Id compliance with tha law, I bog le&ve to present tlie foUowiDg report of the progress of the geological surve; duriug the past season.

BOOFE or TBE PBB8BST KEPOBT.

The near approach of the SDrvej to Its oompletlon, renders it necessary that I shoald at ODCe devote my attention to the various and arduous dntles connected with the preparation of the final re- port. I conceive therefore that I shall best promote the interests of the work by confining myself on this occasion to a very brief sketch of onr investigations during the past season, omitting all such details of our operations in the field and lahoratory as Imve been nsnal in my jirevions reports.

In this view of my duty to the board and the public, I purpose to present no further account of the labonrs of the past season than a hasty notice of the general course of research in each of the dis- tricts in which we have pursued onr enquiries, lesving the full ex- position of what bas been done to be incorporated with the results of all our previous investigations in the comprehensive final report for which I am now actively preparing. This report, the crowning work of the survey, from which alone a jnst estimate of its high economical and scientific value can be formed, it shall be my anx- iona endeavour to present to the legislatnre at tlieir next session.

The death of my valued assistant, Dr. George W. Boyd, towards the close of tlie preceding season, and the withdrawal from the sur- vey of Ur. Samuel Lewis, who had rendered efficient service during the same year, created two important vacancies in the corps, one of which, as the board is aware, was supplied early last spring by the appointment of niy brother, professor James B. Rogers, to wliose aid in the chemical as well as geological part of our w<irk the survey is indebted for many valuable results. Finding great difficulty in filling the otlter vacancy in a suitable manner, and believing that with the corps as already organized, aided by ocoasional services temporarily obtained from others, the field work of the sciv-.'v luuld

be advanced as rapidly as had been anticipated in my last report, I conceived it best to relinqnish the idea of any further appointment for the year, and I may add that I the more readily adopted this course from the belief that the portion of the annual appropriation thus reserved could be expended with far more advantage to the survey in assisting to provide such aid as would be necessary after the expiration of the present geological year, in arranging the cabi- net, and furthering my exertions in preparing for publication the final report with its accompanying maps and sections.

Allotting to my assistants, as usual, those scenes of operation in which from their prior experience they were best prepared to con- tinue their respective labours, I assigned to Mr. C. Briggs, assisted by Mr. T. Bidgway, the task of finishing the exploration of the great coal reffion of the west, to Mr. I. Slade that of making the further researches required to complete our knowledge of the Appalachian belt, and to professor J. ii, Rogers the examination of those por- tions of the middle secondary region between the Potomac river and Albemarle county, and of the upper secondary and tertiary tracts lying along and near the Potomac, which as mentioned in my last report, had been hitherto but imperfectly explored.

In pursuance of the duties thus prescribed, Messrs. Briggs and Ridgway, assisted during a large part of the season by Mr. M. Wells, commenced their investigations by carefully tracing the more im- portant members of the coal series in the southern portion of the valley of the Monongoliela, uniting their work with the results of previous investigations in the neighbouring regions towards the north, and east, and west. Thence they continued their examina- tions to Tygarts valley, tracing the important coal seams of this region from Weston through and across the valley of Buchanans river, and marking the eastern outcrop of the great system of coal measures along the summit and western flank of the Rich mountain. After bestowing the requisite attention upon the structure and com- position of the great parallel ridges in Randolph county, between the Tygarts valley and the front ridge of Alleghany, and marking the general limits and contents of the narrow coal basin included between the Cheat and Shavers mountains, they proceeded to con- nect these observations with those previously made on the Little Kanawha, and in the region lying between this stream and the northern boundary of the state, by additional sections and other in- vestigations extending from the eastern escarpment of the coal rocks to the Ohio river.

Having thus completed the examination of the northern half of the coal region as regards all its important geological features, we continued a similar series of researches towards the south as far as the Great Kanawha, including an investigation of the strata along the Elk river from its head waters to its mouth, and various ex- plorations in Greenbrier, Nicholas, Fayette and Kanawha counties in extension and correction of the results of previous observations.

In the region south of the Kanawha river, careful explorations were made along the three great lines of section formed by the

Gnyandotte river, and the Tug and Lonisa forks of Sandy river, embracing the entire distance trom the eoutheastem escarpment of the coal rocks on the Great Flat Top mountain in Fayette, Tazewell and Bossell counties to the Ohio river, and in connection with these and the researches of former years, various additional observations were made in other lines, with a view of tracing the more impor- tant coal seams over the intervening tracts, and marking the influ- ence of the several axes which are prolonged in a southwesterly direction across this region.

Among the various interesting results developed in the course ot these enquiries, may be mentioned the discovery of the wide exten- sion eastward and southward from the upper part of the Mononga- hela river of the great upper coal seam, known farther towards the north as the Clarksburg or Morgantown seam. Lower down the river this, the most valuable bed of coal embraced in the northern half of our coal region, makes, as mentioned in my last report, its moat eat- ern outcrop along the western base of Laurel bill, and with the ex- ception of one or two narrow tracts, is no where met with in the region eastward of this ridge. But in its extension towards the south, it is permitted by the gradually flattening dips connected with this axis to spread itself widely towards the southeast, and is thus continued in the hills over an extensive district towards Buclianans river, making its final outcrop in the dividing ridge westward of that stream. I may add that the same important seam has also been traced into the hills bordering the Elk river near Suttonsville, and over a district in that vicinity of considerable extent.

While thus adverting to the mineral riches of this portion of the state, I would call attention to the fact, that throughout a large part of the region referred to, as well as much of that lying towards the north and west, the vallies and steep hill sides occupied by the calcareous shales of the coal measures, are covered with a riclily productive soil, whose fertility is continually recruited by materials from the adjoining rocks. In view of this important fact, I may be allowed to express the earnest hope, that the cheering invitation thus proffered to agricultural enterprise, seconded as it now is by an easy communication along the great highways recently con- structed across this region to the Ohio river, will ere long lead to the rapid peopling and cultivation of a valuable, but hitherto ill- appreciated portion of the state.

Results of not less interest have attended our investigations in the region south of the Great Kanawha, where the lower coal meas- ures, retained above the water level by a series of low axes, are extended with almost unbroken continuity over a large part of the area lying between the Flat Top mountain and the Ohio river, and are thus permitted to display their valuable contents in the noble sections formed by the Kanawha, Coal, Guyandotte and Sandy rivers, as well as in an immense number of intervening situations.

In the Appalachian belt, the examination of which was commit- ted to Mr. 1. Slade, our observations though chiefly directed to a review of previous results and the correction and extension of the

seotionol drawings previoualjr formed, as well as the constroction of new sections along other lines of exploration were also in part de- voted to the longitudinal tracing of some of the important lines of dislocation hitherto bat partially followed out, and an examination oontinuonsly of the mineral character of the formations in the grad- ual modifications which they undergo as the j are prolonged towards the southwest. With these researches were associated fiuther meas- urements of the thickness of several of the formations, and obser- vations for determining the heights of important ridges and knobs, not hitherto ascertained.

Of the economical results of our labours in this region, it would be useless to speak at this time, as from their necessary connection with the complex features of the country, they could not be referred to intelligibly without the assistance of a map and sections.

Our researches in the region east of the JBlue Ridge, conducted by professor J. B. Rogers, were in the first place directed to the completion of the several sections from the summit of the ridge to the western margin of the tertiary, which had been left in an unfin- ished state the previous year, and to the construction of additional partial sections m the intervening tracts. They were thn devoted to that portion of the middle secondary region between the Potomac river and Albemarle county, which had been hitherto but partially examined, and while completing the task of tracing the margin of this formation we followed it into Maryland and connected the geology of the adjoining parts of the two states by appropriate sec- tions. A further examination was also made of the upper secondary sandstones from the neighbourhood of Mt Vernon to the Rappa- hannock river, with a view of determining more precisely the limits of the formation, and in aid of this as well as more general objects our observations were carried to some distance within the adjoining primary and tertiary tracts.

By these and collateral researches in the coal measures of Hen- rico, Goochland, Chesterfield and Powhatan, additional light has been cast upon the geological relations of these two closely allied formations to each other, and to the middle secondary rocks, and I may mention as a result of much interest in American geology, that all my observations in these various tracts lead to the conclusion, that while the upper secondary sandstones appertain to the Oolitic period of British geologists, the coal measures, somewhat more an- cient, connect themselves with the Lias, and the middle secondary rocks with the New Red Sandstone.

In the chemical department of the survey, in which I have been chiefly aided by my brother, our progress has been quite satisfac- tory, but the analyses remaining to be executed, make it necessary to continue this branch of our labours throughout the winter.

Numerous sections, framed from observations made during the past season, are now in progress, which together with the detailed reports relating to our labours in the field, will furnish employment for my assistants for some time to come.

From the above sketch of our operations in the field daring the

past aeason, the board will perceive that the progreas of oor re- Bearchea baa been full? coiimieDaQrat witb tbe aoticipations on thia subject eipresaed in my last report, and I take great pleasure in announcing tbe fact, tbat witb the exception of the two counties on tbe Eastern Shore, our field work baa been in all important points completed. In thaa postponing the examination of the coancies east of tlie ChesApeabe, I have t>een gaided bj tbe wiab to advance oar labonrg witb all procticable speed in the other and more difficult parts of the field, which could onlj he dono bj ttjaintaining an an- broken continuity of observation, and that from tbe knowledge al- ready possessed of the very simple geology of tbe district in qnes- tion, I feel quite assured that the requisite explorations can be mode with comparatively little labour. To this remnant of our work, aa well as certain other local examinations ia the marl region and other parts of tbe state, 1 purpose demoting the necesaory attention during the coming season.

OOMPLimON OF THB flURVKT ASI> PBBPARATION OF THK PISAL SEPORT.

Having brought the active labours of the survey thus near to their completion, 1 am now entering upon the task of preparing the final report. Those who like tbe board have been able to follow me and mj aaaiatanta in the diverMlied and ialmrioos reaearches in which we have been actively engaged for nearly aii years, and who reflect upon the iiomecge extent of ground over which onr eiplora- tions have been carried, tbe largest area ever subjected to systematic geolfcol examination in any part of tbe world, will be at once prepared to form a just idea of the number and extent of our re- sale and of the magnitude of the task of producing a full report on the geology of tbe state. To those interested in tbe survey who may not be thus prepared to conceive the extent and nature of such a report, it may euSce to say, tbat liesides embodyiug in a digested form every important result, genera! or local, attained in tbe prog- ress of the work, and of which but partial and unconnected notices have been given in my annual reports, it will comprise an ample series of sections and other drawings illustrating tbe geology of every part of tbe state, together with a geological map of its entire sorfooe, exhibiting eacb formation in its appropriate place.

Snch being the task before me, I feel that it would he qnite im- possible to complete it even in two years from tbe present time, nnlese I am allowed the assistance of my corps until tbe close of tbe geological year in April next, and even with thia asaietance there wilt still remain to be performed so large an amoant of labour con- nected witb the arrangement of the cabinet, tbe preparation of tbe sections and map to accompany ibe final report, and other tasks collateral to that work, and which ought to ho in progress while I am engaged upon it, tbat nnless eomo aid for these purpose's be al- lowed me, it will be impracticable to have the repoit in readiness to he TU'esented to the legislature at ita next session.

The necessity of thus continuing my present ootps in MrricQ

nntil April, will at once appear from considering first that the lahonr of drawing up in systematic form the observations made in the field during the past season, and of constmcting the corresponding sec- tions and maps, is of itself sufiScient to keep my assistants busily employed until near the close of the winter; and, secondly, that these materials if thrown upon my hands in an undigested shape, and unaccompanied by the detailed explanations which the observer alone can give, would be so little available for the purposes of final publication, as to make such a premature disbanding of the corps tantamount to the sacrifice of a large part of the labour and outlay of the last season.

It should moreover be borne in mind that the large mass of de- tails collected in previous years, and out of which I am to construct the final report, will in many instances require to be corrected or modified in accordance with later examinations, and in this impor- tant work it is in the highest degree desirable to have the oppor- tunity of conferring witib those by whom the observations were actually made.

I would therefore respectfully urge upon the board as indispen- sably necessary to enable me to draw up my final report in a form at consistent with the great magnitude and importance of our labours, and within a reasonable time, that the services of my corps as at present organised he continued until the regular close of the geological year in April next.

In connection with this request, it is but proper to remark, that as our first geological year in the beginning of the survey commenced on the 2d of April, and as all the succeeding annual appropriations have been regarded as applying to the successive periods of twelve months from that date, we have always, as the board is aware, em- braced in our year the whole circle of the twelve months terminat- ing at that time, thus giving to the geological a different position from that of th fiscal year though still embracing an ecual amount of time. Presuming that a natural misconception on this point led to the action of the legislature during the last session, arresting the appropriation before the close of our year, and having full confi- dence in the wise economy as well as liberality of that body, I can- not doubt their ready acquiescence in the request above made for the continuance of the appropriation nntil the 2d of April next.

But as already intimated, even after that date and while I am preparing the report, there will remain to be performed other im- portant duties collateral to those of authorship, and essential to the great objects of the survey, which if devolved upon myself alone, would so retard my labours as to. render it impossible, however earnestly I might toil, to have the report in readiness for the legisla- ture during their next session Among the duties here referred to, I would beg leave to specify

1st. 'The arrangemeut and labelling of our large collection of specimens, the gatherings of many years, according to a systematic plan, and in reference to the report-itself a work demanding much time and labour.

2d. The ooropletion and final arrangement of oar namerons sec- tions and other drawings, and the construction and coloaring of a geological map of the state from the varioos partial maps completed or in progress.

dd. The exploration of the Eastern Shore, and snch further ex- amination of certain localities in other quarters of the state as may be demanded in the progress of the report.

Nearly all these labours it will be readily perceived are essen- tially connected with the arrangement of the report and eould <mly he carried on consistently, with the desirable harmony of plan, at the same time that I am engaged upon that teorh.

Thus impressed with the magnitude of the task I have to per- form, and earnestly desirous of completing it at an early day, I feel it my duty to request of the legislature a further small appropriation to be applied after the close of the geological year, in aid of the col- lateral duties above described. The least amount adequate to these purposes on the most restricted scale of expenditure, would, I con- ceive, be $2500, out of which I would propose paying the salaries of those employed, and defraying other necessary expenses.

In calling upon the legislature for this special appropriation, I would particularly ask attention to the fact, that the sum required falls short of the unexpended portions of the two last annual appro- priations, and that therrfgre ite devotion to the purposee of the eurvey has in effect been already authorized, and I would wish it to be borne in mind that in organizing my corps for the last two years on such a scale as to make the annual expenditure less by more than a thousand dollars than the sum allowed by the legislature, I have had steadily in view the necessity of aid such as that now requested, collateral to the preparation of my report, and essential to a proper comple- tion of our labours.

In making this request, therefore, nothing more is asked than the anthority to apply, to purposes essential to the completion of our work, a part of the sum providently ived out of the previous ap- propriations, through an anxious regard to the most efficient and economical application of the funds of the state.

It gives me great pleasure to be able to add, that with the ap- propriation for the present season continued to the end of the goo- logical year, and with the authority above requested for the em- ployment of $2500 dollars of nnexpended appropriations, the entire expenses of the survey from its regular organization in 1836 to the completion of the final report, will still not amount to more than $45,000.

This sum, as the board is aware, falls short by about 5000 dollars of the amount mentioned in my report of 1836, as probably neces- sary for the execution of the survey, and bears but a small ratio to the sums devoted to similar surveys in other states of less area and of more simple geological structure.

In conclusion, I would remark, that while I am duly sensible of the magnitude and difficulty of the tasks I have still to perform, before the fruits of our researches can be made available to the

public and men of science at home and abroad, I am cheered by an increasing sense of the permanent benefits which are co flow from our own and the other great surveys now approaching their com- pletion. Regarding with friendly emulation the labours of all who are united in the grand enterprise of making known the geology, and through it, the native resources of our common country, I may be indalged in expressing the satisfaction with which I reflect upon the peculiar productiveness and grandeur of that portion of the field which it has heen my province to explore ; nor can I close the pres- ent report without renewing the earnest wish, not nnmingled with patriotic pride, that I may he enabled to give to the world the em- bodied results of our labours in a form worthy of the magnificent truths disclosed in the geology of our state, and of the noble aspira- tions of its liberal and enlightened citizens.

Wm. B. Rogbbs.

Analyses

or

WATERS OF THE PELNCIPAL MmERAL SPRINGS

or

Virginia.

Results Of Analyses.

In view of the cliaracteristio or typical ingredients of mineral springs, they may be divided into :

1. Carbonic or Addulotu, in which Carbonic Acid and Carbonates

give' character to the water, particularly Carbonates of Lime and Magnesia.

2. Sulphurous, in which Sulphuretted Hydrogen or Hydrosulphates,

or both, are predominant.

8. Alkaline, characterised by Carbonate of Soda.

4. Chalyheate, marked by the prevalence of Oxide of Iron or Car- bonate of Iron. In the latter case the Carbonic Acid which holds np the Carbonate of Iron is often in sufficient amount to render the spring decidedly acidulous. Such waters might be termed Acidulous- Chalyheate, The Oxide of Iron in the ordi- nary Chalybeate is combined with Crenic and Apocrenic acids.

6. Sulphuric or Alumino-Chalyheatc, containing chiefly Sulphates of Alumina and Iron with free Sulphuric Acid. These are the Alum and Copperas Springs of some parts of our Appalachian belt.

6. Brine Springs, marked by the predominance of Chloride of So- dium.

Pbikoipal Ingredients Found In Mineral 8Prin08.

Carbonate of Lime,

Iodides,

" of Magnesia,

Bromides,

" of Soda,

Silica,

" of Iron,

Caustic Soda,

of Alumina,

Ilydrosulphuret,

Sulphate of Lime,

Sulphides of Sodium and Magnesium,

" of Soda,

Organic Matter,

" of Iron,

Carbonic Acid,

" of Alumina,

Sulphuretted Hydrogen,

Chloride of Sodium,

Oxygen,

" of Calcium,

Nitrogen,

of Magnesium,

Carburetted Hydrogen.

WUte Sulphur Sprincs, Greenbzier Co., W. Va.

Temperature variable but always thermal — from 61° to 65° Fahr- enheit.

Solid matter procured by evaporation from 100 cubic inches, weighed after being dried at 212°, 65.54 grains.

Quantity of eadi solid ingredient in 100 cubic inches, estimated as perfectly free from water :

Sulphate of Lime, 81.680 gruns.

Sulphate of Magnesia, 8.241

Sulphate of Soda, 4.060 "

Carbonate of Lime, 1.580 "

Carbonate of Magnesia, 0.506

Chloride of Magnesium, 0.071 "

Chloride of Calcium, 0.010 "

Chloride of Sodium, 0.226 "

Proto-Sulphate of Iron, 0.069 "

Sulphate of Alumina, 0.012 "

Earthy Phosphates, a trace.

Azotized Organic Matter blended with a pro- portion of Sulphur, about 5 grains.

Iodine combined with Sodium and Magnesium.

Volume of each of the gases in a free state contained in 100 cubic inches :

Cubic locbes.

Sulphuretted Hydrogen, 0.06 to 1.30

Nitrogen, 1.88

Oxygen, 0.19

Carbonic Acid, 8.67

While the proportion of the saline ingredients has been found to suffer but little variation with the season and weather, that of the Sulphuretted Hydrogen and the Sulphur united with Azotized Or- ganic Matter has been observed to show very marked fluctuations.

Salt Sulphur Springs, Konroe Oc, W. Va.

Old Spring.

Temperature variable, from 49° to 56°.

Solid matter procured by evaporation from 100 cubic inches, weighed after being dried at 212°, 81.41 grains.

Quantity of each solid ingredient in 100 cubic inches, estimated as perfectly free from water :

Sulphate of Lime, 86.756 grains.

Sulphate of Majniesia, 7.888 "

Sulphate of Soda, 9.682 "

Carbonate of Lime, 4.445 "

Carbonate of Magnesia, 1.434 "

Chloride of Magnesium, 0.116 "

Chloride of Sodium, 0.638 "

Chloride of Calcium, 0.026 "

Iodine probably combined with sodium, a minute but distinct trace.

An Azotized organic matter blended with

Sulphur, 49.000 grains.

Peroxide of Iron derived from Proto-sul- phate, 0.042 "

Earthy Phosphates, a trace.

Volume of each of the gases, contained in a free state in 100 onbio inches :

Cnbic ioches.

Salpburetted Hydrogen, 1.10 to 1.60

Nitrogen, 2.05

Oxygen, 0.27

Carbonic Acid, 6.75

The bubbles of gas that are seen adhering to the sides of the spring are composed almost entirely of Nitrogen.

New Spring.

Temperature variable.

Solid matter procured by evaporation from 100 cubic inches, weighed after being dried at 212", 76.87 grains.

The foregoing list of ingredients in the Salt Salphur water ap- plies to the New as well as the Old Spring, the former having a rather smaller amount of saline matter in general, though in some ingredients surpassing the other. It has been very minutely analysed, and is the first of all the waters in which I was enabled to detect traces of Iodine, which it contains in larger amount than the Old Spring, and indeed than most of the other waters in which I have been so fortunate as to discover this material.

Humphrey's Spring, Uomroe Oc, W. Va.

(Between the Salt Sulphur and Red Sulphur.)

Temperature variable, ranging between 50° and

Solid matter procured by evaporation from 100 cubic inches, weighed after being dried at 212"*, 49.91 grains:

Quantity of each solid ingredient in 100 cubic inches, estimated as perfectly free from water :

Sulphate of Lime, 8.730 grains.

Sulphate of Magnesia, 4.232 "

Sulphate of Soda, 15.540 "

Carbonate of Lime, 6.380

Carbonate of Magnesia, 1.010 "

Chloride of Sodium, 2.734 "

Chloride of Magnesium, 1.610 "

Iodine probably combined with Sodium. ... a trace. Peroxiae of Iron derived from proto-sul- phate, a trace.

Sulphur mingled with organic matter, in considerable amount.

Gases contained in this water, in quantities not yet determined :

Sulphuretted Hydrogen, Carbonic Acid, Nitrogen, Oxygen.

Bed Sulphur Spring*, Monroe Co., W. Va.

Temperature variable, from 50* to 54°.

Solid matter procured by evaporation from 100 cubic inches, weighed after being dried at 212°, 7.587 grains:

Quantity of each solid ingredient in 100 cubic inches, estimated as perfectly free from water :

Sulphate of Lime, 0.923 grains.

Sulphate of Magnesia, 0.064 "

Sulphate of Soda, 1.241 "

Carbonate of Lime, 2.493 "

Carbonate of Magnesia, 0.788 "

Chloride of Sodium, 0.042 "

Chloride of Magnesium, a trace.

Sulphides, in minute quantity.

Sulphur mingled with a peculiar organic mat- ter, 8.000 grains.

Peroxide of Iron, a trace.

Iodine, a very faint trace.

Volume of each of the gases, contained in a free state in 100 cubic inches:

Cable incheB.

Sulphuretted Ilydrogen, 0.616

Carbonic Acid, 8.190

Nitrogen, 2.320

Oxygen, 1,000

Oobreoted.

Sulphuretted Hydrogen, 0.462

Carbonic Acid, 2.856

Nitrogen, 3.115

Oxygen, 0.420

Sweet Sprinffs, Konroe Co. W. Va ,

(Drinking spring, near the Hotel.)

Temperature, 74°.

Solid matter procured by evaporation from 100 cubic inches, weighed after being dried at 212°, 32.67 grains:

Quantity of each solid ingredient in 100 cubic inches, estimated as perfectly free from water :

Sulphate of Lime, 5.703 grains.

Sulphate of Magnesia, 4.067 "

Sulphate of Soda 2.740 "

Carbonate of Lime, 13.013 "

Carbonate of Magnesia, 0.357

Ohloride of Sodiuo, 0.060 grains.

Chloride of Magnesium, 0.186 "

Chloride of Calcium 0.065 "

SiHoa, ; 0.076 "

Organic Matter, in considerable amount.

Earthy Phosphates, a trace.

Peroxide of Iron, : 0.161 grains.

Volume of each of the gases contained in a free state in 100 cubic inches of the water :

Onble inches.

Carbonic Acid, 87.17

Nitrogen, 1.87

Oxygen, a trace.

Sulphuretted Hydrogen, a trace.

Compoffltion of 10 Cubic inches of the mixed gases rising in the form of bubbles in the spring :

Cubic inches.

Nitrogen, 7.17

Carbonic Acid, 2.83

Sweet Sprizurst sontlini border of Alleffluuiy Ck>., Va. New Red Spjeono, ob Champagne Chalybeate. (P. Roger8\)

Temperature of eastern stream, 78° ; western stream, 75°.

Solid matter procured by evaporation from 100 cubic inches weighed after being dried at 212°, 40.76 grains.

Quantity of each solid ingredient in 100 cubic inches, estimated as perfectly free from water :

Sulphate of Lime, 14.228 grains.

Sulphate of Magnesia, 8.107

Sulphate of Soda, 1.400 "

Carbonate of Lime, 9.411 "

Carbonate of Magnena, 1.166

Chloride of Sodium, 0.037 "

Chloride of Magnesium, 0.680

Chloride of Calcium,. 0.010 "

Peroxide of Iron, 0.320 "

Silica, 0.180 "

Volume of each of the gases contained in a free state in 100 cubic inches of the water :

Cubic inches.

Carbonic Acid, 46.10

Nitrogen, 2.57

Oxygen, 0.20

Sulphuretted Hydrogen, a trace.

Composition of 10 cubic inches of the mixed gases rising in the form of bubbles in the spring:

Coble lochei.

Nitrogen, 6.26

Carbonic Acid, 8.76

Ooroposition of 100 grains of the ochreous deposit which collects in the basin of the spring:

Hjdrated peroxide of Iron, 66.9 grains.

Carbonate of Lime, : 8.7 "

Silica, 17.4

Alumina, 1.6 "

Uncombined Water, 5.4 "

In this deposit it is not improbable that a part of the peroxide of Iron is united to the silica forming a silicate similar to that de- scribed by Davy as occurring in the water at Lncca.

Old Red Sprikg.

Temperature,

Solid matter procured by evaporation from 100 cubic inches, weighed after being dried at 212°, 88.84.

Quantity of each solid ingredient in the 100 cubic inches esti- mated as perfectly free from water :

Sulphate of Lime, 9.18 grains.

Sulphate of Magnesia, 6.76 "

Sulphate of Soda, 1.44 "

Carbonate of Lime, 10.26

Carbonate of Magnesia, 1.82

Chloride of Sodium, 0.30

Chloride of Magnesium, ( .

Silica, 0.12

Peroxide of iron,

Organic Matter,

Gases contained in a free state in 100 cubic inches of the water: Carbonic Acid, Nitrogen,

Sulphuretted Hydrogen. The amount of each of these gases in the water has not yet been

determined — nor has the presence of oxygen been ascertained.

Composition of 10 cubic inches of the mixed gases rising in the form of bubbles in the spring :

Cable inch8.

Nitrogen, ... 7.78

Carbonic Acid, 2.27

Sweet Spbinq No. 2, ob Field Spbino.

A very copious spring — situated in Mr. Rogers' field further down the valley than any of the others. Temperature, 72°.

Solid matter procured by evaporation from 100 cubic inches weighed after being dried at 212°, 41.20 grains.

((

J

Volame of each of the gases contained in a free state in 100 cubic inches of the water :

Cubic inches.

Carbonic Acid, 30.66

Nitrogen, 1.66

Oxygen, a trace.

Composition of 10 cabic inches of the mixed gases rising in the form of bubbles in the spring :

Cable inches.

Nitrogen, 7.7

Carbonic Acid, 2.3

Bubbling ForKTAiN.

About 200 yds. below the New Red Spring ; issues from the soil accompanied by a very copious discharge of gas. Temperature, Composition of 10 cubic inches of the mixed gases:

Nitrogen, 8.13

Carbonic Acid, 1.88

Oxygen, 0.54

Hot Spxixiffs, Bath Oo., Va.

BOILEB BaTD.

Teraperatare, 106°.

Solid matter procured by evaporation from 100 cubic inches, weighed after being dried at 212", 13.26 grains.

Quantity of each solid ingredient in the 100 cubic inches, esti- mated as perfectly free from water :

Sulphate of Lime, 1.750 grains.

Sulphate of Magnesia, 0.890 "

Sulphate of Soda, J.437 "

Carbonate of Lime, 6.567 "

Carbonate of Magnesia, 1.153

Chloride of Sodium with traces of Chloride

of Magnesium and Calcium, 0.570

gilica, 0.703 "

Peroxide of Iron, 0.020 "

Organic Matter, in small amount.

Volume of each of the gases contained in a free state in 100 cnbic inches of the water :

Cable inches.

Carbonic Acid, 11.007

Nitrogen, 1.790

Oxygen, 0.220

Sulphuretted Hydrogen, a trace.

Composition of 10 cubic inches of the mixed gases rising in the form of bubbles in the spring :

Cobio Indiea.

Nitrogen, 8.48

Garbonio Acid, 1.02

Oxygen, 0.50

Red Spbing.

(O

Temperatnre — on one side 105**, on the other 96*

Solid matter procured by evaporation from 100 cubic inches, weighed after being dried at 212% 15.61 grains.

Ingredients the same, and in nearly the same proportions as the preceding. The chief difference is in the larger amonnt of Peroxide of Iron, which in the 100 cubic inches is 0.84 grains.

Volume of each of the gases contained in a free state in 100 cubic inches of the water :

Cable inches.

Carbonic Acid, 11.60

Nitrogen, 1.60

Oxygen, 0.24

Temperate or Pleasure Bath.

Temperature, where the spring enters the east side, 102**. Composition of 10 cubic inches of the mixed gases rising in the form of bubbles in the spring:

Cable fnchea.

Nitrogen, 8.75

Carbonic Acid, 1.26

Spout.

Temperature far up the tube, 108®.

Solid matter procured by evaporation from 100 cubic inches, weighed after being dried at 212°, 12.73 grains.

Cubic inches.

Free Carbonic Acid in 100 cubic inches, 11.82

Hot Chalybeate in Barrel.

Temperature, 102i°.

Solid matter procured by evaporation from 100 cubic inches, weighed after being dried at 212°, 13.12 grains.

The same ingredients, in very nearly the same proportions as in the Boiler Bath, the Oxide of Iron being in rather greater quantity. Volume of each of the gases, contained in a free state in 100 cubic inches of the water :

Coble Inebes.

Carbonic Acid, 11.5

Nitrogen, 1.8

Oxygen, 0.2

Composition of 10 cubic inches of the mixed gases rising in the form of bubbles in the spring:

Cable iDcheai

Nitrogen, 7.5

Oxygen, 0.6

Carbonic Acid, 1.9

SWKET SrKINO.

Temperate, 93

Solid matter procured by evaporation from 100 cnbic inches, weighed after being dried at 212°, 14.5 grains.

Ingredients the same and nearly the same proportions as the pre- ceding.

Volume of each of the gases, contained in a free state in 100 cubic inches of the water:

Cable incbes.

Carbonic Acid, 11.70

Nitrogen, 2.10

Oxygen, 0.85

Warm Bpxiagn, Principal Bath, Bath Co.t Va.

Temperature: of the spring generally, 96®; of the principal stream as it enters, 97''.

Solid matter procured by evaporation from 100 cubic inches, weighed after being dried at 212 10.64 grains.

Quantity of each solid ingredient, in the 100 cubic inches, esti - mated as perfectly free from water :

Sulphate of Lime, 6.128 grains.

Sulphate of Magnesia, 0.462 "

Sulphate of Soda, 0.180 "

Carbonate of Lime, 2.098 "

Carbonate of Magnesia, 0.694 "

Chloride of codinm with faint traces of Chloride of Magnesinm and Calcium, or- ganic matter probably Crenic Acid, Silicft, Oxide of Iron in part nnited with organic matter.

Volume of each of the gases, contained in a free state in 100 cubic inches of the water :

Cable inohefl.

Sulphuretted Hydrogen, 0.19

Nitrogen, 1.62

Carbonic Acid, 2.64

Composition of 10 cubic inches of the mixed gases rising in the form of bubbles in the spring :

Cable ladieB.

Nitrogen, 9.88

Carbonic Acid, 0.12

Sulphuretted Eydrogen, a trace.

Oxygen, a trace.

The drinking spring presents the same ingredients in the same proportiun.

Blue Sulphur, Greenbrier Co., W. Va.

Temperature variable from 49° to 66°.

Solid matter procured hj evaporation from 100 cnbic inches, weighed after being dried at 212°, 44.62 grains.

Sulphate of Lime, 20.152 grains.

Sulphate of Magnesia, 2.760 "

Sulphate of Soda, 7.021

Carbonate of Lime, 2.185

Carbonate of Magnesia, 0.481 "

Chloride of Magnesium, 0.407 "

Chloride of Sodium, 1.868 "

Chloride of Calcium, 0.005

Iodine probably combined with sodium, ... a trace. Sulphur mingled with a peculiar organic

matter, in considerable amount — say, 5.000 "

Peroxide of Iron derived from Protosul-

phate, 0.015 "

Volume of each of tbo gases contained in a free state in 100 cubic inches :

Cubic Inches.

Sulphuretted Dydrogen, 0.573

Nitrogen, 3.250

Oxygen, 0.500

Carbonic Acid, 2.750

The gas adhering to the sides of the spring is nearly pure Nitro- gen.

SPBIiYGS CO.WTALVING FREE SULPHURIC ACID, Alum Spring— Bookbridffe Co.* Va. Temperature varying from 50° to 56°.

Contents in 100 cubic inches.

Sulphuric Acid, 14.398 grains.

Sulphate of Protoxide of Iron, 2.035 "

Sulphate of Alumina, 6.916 "

Sulphate of Lime, 0.150 "

Sulphate of Magnesia, a trace.

Brinkley's Alum Spring, at the eastern foot of Warm Bprixkg fountain (now Bath Alum. Bath Co., Va.).

Temperature varying from 50° to 56°,

Contents in 100 cubic inches.

Sulphuric Acid,

Sulphate of the Protoxide of Iron,

Sulphate of Alumina,

Sulphate of Lime,

Sulphate of Magnesia,

Sour Sprinff at White Sulphur— Marsden's, Greenbrier Co.* W. Va.

Ccntents in 100 eiibie inches.

Sulphuric Acid,

Sulphate of Protoxide of Iron,

Sulphate of Alumina,

Sulphate of Lime,

Sulphate of Magnesia, . .

Alnm Sprlnar, Bookbridse Co., Va. Temperature varying from 50" to 56°.

Contents in 100 euhie inches.

Sulphuric Acid 18.508 grains.

Protoxide of Iron, 0.967 "

Alumina, 8.875 "

MSeaia,':;::::: :;;':::::;.:::: i minute quantity.

Brinkley's Sour Sprinar, at the eastern foot of the Warm Springr Kountain (now Bath Alum, Bath Co., Va.).

Contents in 100 cubic inches.

Sulphuric Acid, 17.620 grains.

Protoxide of Iron, 1.296 "

Alumina, 2.850 "

Lime, 0.020 "

Magnesia, a trace.

Sour Spring near the White Sulphur-Oreenbrler Co., W. Va.

Contents in 100 eubie inches.

Sulphuric Acid, 48.830 grains.

Protoxide of Iron, 12.120 "

Alumina, 16.206 "

Lime 5,648 "

Magnesia, a trace.

Bawley Springs, Bookinfirham Co., Va.

Temperature of the larger of tlie two adjacent springs, 52°. " " smaller " " 54 " " spring higher up the hill, 52°.

Solid matter procured by evaporation from 100 cubic inches of the water from the larger spring yielded :

Peroxide of Iron, 0.368 grains.

Carbonate of Lime, 0.050 "

Chloride of Sodium, )

Chloride of Magnesium, V 0.860 "

Sulphate of Sodium,

Organic Matter, in considerable amount.

No free gas rises in either of the springs, nor is it ascertained that the water contains Carbonic Acid. It yet remains to be deter- mined whether the Iron is in a state of Protocarbonate or of Crenate.

Gmy Stilphur Aperient Sprisflr, Va.

Temperature variable from 60" to 68°.

Solid matter procured by evaporation from 100 cubic inches, weighed after being dried at 212°, 10 02 grains.

Quantity of each solid ingredient in 100 cubic inches estimated as perfectly free from water :

Carbonate of Soda, 1.746 grains.

Sulphate of Soda, 0.365 "

Chloride of Sodium, 0.885 "

Chloride of Potassium, a trace.

Carbonate of Lime, 2.078 "

Carbonate of Magnesia, 2.468

Silica held in solution bv the Carbonate of

Soda, 0.750 "

Peroxide of Iron derived from Protocarbon- ate, 0.090 "

Organic matter containing Nitrogen, a large amount.

Carbonate of Ammonia, a trace.

Volume of each of the gases contained in a free state in 100 cubic inches of the water:

Cubic inchoa.

Carbonic Acid, 6.182

Sulphuretted Hydrogen, 0.410

Nitrogen, 3.000

Oxygen, 0.400

The bubbles adhering to the sides of the spring consist almost entirely of Nitrogen.

Gray Sulphur Antl-dyepepUo Spring, Va.

Temperature variable from 50° to 58°.

Solid matter procured by evaporation from 100 cubic inches, weighed after being dried at 212°, 9.98 grains.

Quantity of each solid ingredient in 100 cubic inches estimated as perfectly free from water :

Carbonate of Soda, 2.462 grains.

Sulphate of Soda, 0.432 "

Chloride of Sodium, 0.210

Carbonate of Lime, 2.840 "

Carbonate of Magnesia, 1 .682 "

Silica held in solution by the Carbonate of

Soda, 0.823 "

Peroxide of Iron derived from Protocarbon- ate, 0.050 "

Organic Matter containing Nitrogen, a large amount.

Carbonate of Ammonia, a trace.

Chloride of Potassium, a trace.

Volume of each of the gases contiuned in a free state in 100 cubic inches of the water :

Cabio Inches.

Carbonic Acid, 6.537

Sulphuretted Hydrogen, 0.203

Nitrogen, 8.070

Oxygen, 0.400

The bubbles adhering to the sides of the spring consist almost entirely of Nitrogen.

Howard's Idok-in Haxdy Ooimtyt W. Va.

A quantity of the water not very accurately measured, but be- lieved to be about 200 cubic inches, yielded of solid matter, 8.63 grains. This contsdned :

Carbonate of Soda, 5.832 grains.

Chloride of Sodium, 0.460

Sulphate of Soda, 0.189

Carbonate of Lime, 0.441

Carbonate of Magnesia, 0.200

Peroxide of Iron, 0.120

Silica held dissolved by the Carbonate of

Soda, 0.370 "

Organic Matter, in considerable amount.

The gases contained in this water are chiefly Carbonic Acid and Sulphuretted Hydrogen.

ZMokBon's Solphnr Spxlncr in AUoffhany Ooimty, Va.

Temperature variable — abont 54 200 cubic inches of this water yield by evaporation of solid matter, 7.47 grains. This contained:

Carbonate of Soda, 2.255 grains.

Chloride of Sodium, 0.050

Chloride of Potassium, a trace.

Carbonate of Lime, 2.480 "

Carbonate of Magnesia, 1.500 "

Peroxide of Iron probably derived from

protocarbonate, 0.030 "

Silica partly held dissolved by the Carbonate

of Soda, 0.960

Organic Matter, in small anoount.

The gases contained in this water are chiefly Sulphuretted Hydro- gen and Carbonic Acid.

I>ibbrell*s Spring, (now Danrer'a, Botetoazt Co., Va.).

Temperature variable, from 50® to 68°. Solid matter procured by evaporation from 100 cubic inches, weighed fter being dried at 212% 14.75 grains.

Quantity of each solid ingredient in 100 cubic inches estimated as perfectly free from water :

Carbonate of Soda, 2.486 grains.

Sulphate of Soda, 0.914

Chloride of Sodium, 4.116

Chloride of Potassium, a trace.

Carbonate of Lime, 8.435

Carbonate of Magnesia, 0.875

Peroxide of Iron derived from Proto-carbon-

ate, 0.4C0

Silica, held dissolved by the Cai'bonate of

Soda, 0.570

Organic matter containing Nitrogen not culpa- ble of very accurate determination, about 2.000 Carbonate of Ammonia, a trace.

Volume of each of the gases contained in a free state in 100 cubic inches of the water :

Cobic iocbet.

Carbonic Acid, 11.356

Sulphuretted Hydrogen, 0.910

Nitrogen and Oxygen, in minute quantity.

The above amount of Carbonic Acid is more than sufficient to convert the Carbonates into Bi-carbonates. The additional dose of Carbonic Acid required for this, and the remainder which is un-

combined are as follows :

Cnbte tncbtt.

Second dose of Carbonic Acid, 6.546

Uncombined, 4.810

The gas which rises from time to time in the spring is a mixture of Carburetted and Sulphuretted Hydrogen — chiefly the former.

UoHenry'B Thermal, Soott Co., Va.

Temperature, 68".

Solid matter procured by evaporation from 100 cubic inches, weighed after being dried at 212'\ 26.04 grains.

Quantity of each solid ingredient in 100 cubic inches, estimated as perfectly free from water :

Sulphate of Lime, 7.827 grains.

Sulphate of Magnesia, 0.248 "

Sulphate of Soda, 8.771 "

Carbonate of Lime, 6.343

Carbonate of Magnesia, 1.544

Chlorides of Sodium, Magnesium and Cal- cium, 0.680

Peroxide of Iron, a trace.

Organic Matter, a minute quantity.

Amount of free Carbonic Acid, very considerable, but not yet accurately determined. Little or no gas rises in bubbles in the Blaring.

Bdmondson'B Spriziflr- Jexmlnflrs Ghtp Boad, Augusta Co., Va.

Temperature from 50° to 54°.

Solia matter procured by evaporation from 200 cubio inches, 7.88 grains.

Quantity of each solid ingredient in 200 cubic inches estimated as pectly free from water :

Carbonate of Soda, 1.322 grains.

Bulphate of Soda, a trace.

Chloride of Sodium, 0.122

Carbonate of Lime, 2.768 "

Carbonate of Magnesia,

Peroxide of Iron probably derived from

Proto-carbonate,

Silica held dissolved by the Carbonate of

Soda,

Organic Matter,

The gases contmned in the water are chiefly Sulphuretted Hy- drogen and Carbonic Acid.

Wilson's Tliennal, Botetourt Ck>., Va.

Temperature, 65°.

Solid matter procured by evaporation from 100 cubic inches, weighed after being dried at 212°, 22.85 grains.

Quantity of each solid ingredient in 100 cubic inches estimated as perfectly free from water :

Sulphate of Lime, 8.090 grains.

Sulphate of Magnesia, 1.295 "

Sulphate of Soda, 3.582 "

Carbonate of Lime, 5.000 "

Carbonate of Magnesia, 0.520

Chlorides of Magnesium and Sodium, . . . minute quantity.

Peroxide of Iron, a trace.

Organic Matter,

Silica,

The amount of free gft contained in this water has not yet been determined. There is little doubt that it consists of Carbonic Acid with a small admixture of Oxygen and Nitrogen gases.

The bubbles occasionally rising in the spring, are composed of the same three gases — the Nitrogen being in much larger volume than either of the others.

Tellow Sulphur Springs— Kontffomary County, Va.

Temperature, 54°.

Solia matter procured by evaporation from 100 cubic inches weighed after being dried at 212°, 48.21 grains.

Quantity of each solid ingredient in 100 cubic inches estimated as perfectly free from water :

Salpbate of Lime, 27.42 grains.

Sulphate of Magnesia, 8.10 "

Sulphate of Soda, 0.31 "

Carbonate of Lime, 4.32

Oarbonate of Magnesia, 0.85 ''

Chloride of Sodium, 0.72 "

Chloride of Magnesium, a trace.

Peroxide of Iron, quantity small, not yet determined.

Organic Matter, somewhat abundant

The gases contained in the water are Carbonic Acid, Nitrogen and Oxygen, with a faint trace of Sulphuretted Hydrogen.

Preston's Springr- Uontsomery County, Va.

Temperature, 64®.

Solia matter procured by evaporation from 100 cubic inches, weighed after being dried at 212°, 60.87 grains.

A complete analysis of this water has not yet been made. So far as examined, its composition has been found almost identical with that of the preceding.

Temperatures of the Warm, Hot, and Sweet Springs, as ob- served by J, A. ChevaUie, Esq., in 1806, and by my- self and Dr. J. B. Rogers in I8SJ1. and 1838.

Particular Spru9C9.

Warm Springs, Bath,,

96*

ditto, Drinking Spring,. Hot Springs, Spout, i 108'

ditto. Ladies' Boiler, when ttiU, '

ditto. Ladies' Boiler, m en- tering stream, ... . I

ditto, Gentlemen's Boiler, entering stream,. .

ditto, Besenroirmto which , the Spout empties,

ditto, Chalybeatein Barrel,

ditto. Bed spring in mead- ow near Boiler. .

ditto. Warm Spring adja- cent to Barrel Spring,

ditto. Temperate, or Pleas- ure Bath,

ditto. Limestone Springun-

der the hill,

ditto. Freestone Spring...

Sweet Springs, Bath

ditto, Rogers' Red Spring,

cUtto, Old Red Spnng at

mill,

102*

98*

92*

68* 58*

74*

75*

11)34 Miil 1838.

96* and 97*'

96" 108*'

105' and IOC'

107*

108*

102* 102*

96* and 105*

92* 102*

64* 68* 74*

Rcmaritc

The former the gen- eral temperature of bath, the latter of the principal stream as it en- ters.

The latter taken highup the spout, temperatureat its mouth 108*.

At opposite sides.

At the entrance of stream.

76*

Table of mean temperature of the air at the Warm Springs and at Richmondy for each month from November 1834, to October, 1835, inclusive.

1835!

November,

December,

Janiuuy,

Februaiy,

March,

June,

July,

August.

Septemoer,

October,

Mean of 12 months.

Wann Spring!.

lUclUMBd.

45.4 86M 34'.4 26.6 49.6 61'.0 65.4 70.6 69.7 68.8 65.4

50*.9

47*.86 89'.67 38'.86 82M0 46*. 6 66'. 8 66'. 0 76%60 78'. 6 62". 6 60'.67

W. 8

Subteeeanean Temperatuee

In Toe

Coal Mines Of Eastern Virginia.

ObSEBVATIONS of SlTBTEBRAlTEAN TeHPERATUBE IN THE

Coax Mines op Eastern Virginia.

Fkox Tkaxs. op thb Absoo. op Aubbioak Oeolooibib akd Natusalibts, liMO-1842. !

Thb important law of an angmenting teraperatare as we descend I

to considerable depths beneath the surface of the earth, has, it is well known, been amply demonstrated in regard to Earope, by the nnmerous observations made in the mines and artesian wells of that portion of the globe, but with the single exception of Ilamboldt's observations in Mexico, no direct recorded proof has yet been fur- nished of its direct applicability to the Contment of America. The results detailed in the present communication, forming the first pub- lished confirmation of this law as regards any part of the United States will, therefore, it is conceived, be viewed as an important contribution to our knowledge on the sabject and will, it is hoped conduce to more extended observations of the same description in other parts of our country, where the requisite opportunities exist.

The mines in which these results have been obtained, lie in the most productive part of tlie Oolite coal-measures of Eastern Vir- ginia, and are of various depths from 100 to nearly 800 feet. These coal-bearing strata rest upon an irregular basin -shaped floor of sienitic and gneissoid rocks, which forms the lower limit of the workings, and is penetrated for a few feet by some of the deeper shafts, as well as by the shallow ones nearest the margin of the field. They consist in great part of felspathio and micaceous sand- stone, the coarser beds of which, formed of the almost unworn ma- terials of the neighboring crystalline rocks compactly reunited, are sometimes scarcely distinguishable from the weathered portions of the parent mass.

The coal, consisting of a single seam, or of two contiguous seams, having an aggregate thickness varying from twenty to fifty feet, lies within a few feet and sometimes a few inches of the undulating floor, separated from it by bituminous slates and shales. Beds of the latter material, abounding in impressions of plants, and in some localities with those of flsh, rest directly upon the principal mass of coal, and occupy the interval between the seams, where there are two.

The most common dip is towards the west, often at a very high angle, but owing to original irregularities in the gneissoid floor, and enormoDs dislocations subsequent to the filling up of the basin, the strike and inclination of the beds ai*e subject to sudden and great transitions.

The open texture, high inclination, and fractured condition of the strata, favoring the descent of streams from above, cause a large influx of water into many of the workings. This forming part of the liquid collected in the wells at the bottom of the principal shafts, prior to its removal by the buckets, imparts as I have always found, a lower temperature to the mass of water there accumulated than is proper to the bottom strata. The small streams flowing from be- tween the surface of the granite and the ooal, or from the rocks above the coal, have, on the contrary, always presented a close ap- proximation to the temperature of the strata from which they make their escape. I have therefore whenever practicable, resorted to such streams, occasionally comparing their temperature with that of the aoining rocks, by a thermometer, duly inserted in the mass.

8ome of the following observations, it will be seen, were made in workings in active operation, and where the heating effects of the workmen, mules, and lamps, miht be supposed to have made the results too high. The amount of their influence, however, could not have been considerable, as the temperature was determined by plunging the thermometer into a body of water continually replen- ished from the rock. Indeed, as will bo proved in the sequel, this influence upon the average result was more than compensated by the cooling effect of the drippings from above.

The remaining observations were made in shafts just completed or in progress, and where the chief modifying influence was the cooling agency of the drippings from the higher beds.

I. Obsebvations made in Mines actually ob but lately in

Opebation.

1. At MilVs and Reed* Mine, called the Creek pit, the tempera- ture was taken at three different levels, by plunging the thermometer for some time into the water collected at the bottom of the main shaft, and the shafts connecting the lower levels. The amount of water accumulated at these points was very considerable, and the liquid was continually drawn off by the engine and replenished from the galleries of the mines. The following were the results:

Depth. Temperature.

318 feet, 595

375 " 61

420 " 63

2. Oreenhole Pit. This is one of the comparatively shallow mines at the margin of the field. When the observation was taken there were but few hands employed in it. The temperature ob-

served was that of a ooUection of water at the bottom of the shail, about a foot in depth. Result :

Dh, Temperature. 100 feet, 58

8. Engine Pit belonging to the Black Heth Co. — The air of this mine was obviously a good deal heated when the workings were in active progress, and I therefore selected for my observations a gal- lery remote ft'om any present operations, and in which no work had been done for some time. The thermometer was immersed in a pool of water about 18 inches deep continually supplied from the neighboring strata. It was afterwards inserted for some time into the rock of the floor, and with the same result, which was — Depth, Temperature, 412 feet, 63°.

The temperature of the water at the bottom of the main shaft of this mine was found to be 61.5 ; but in this case it was evident that a large amount of liquid flowed from the upper strata and thus reduced t£e temperature of the whole.

4. WilU and MiehaeVs Pit, — The works were in active progress

in this mine when the observations were made. The temperature

first noted was that of the water at the bottom of the main shaft ;

the second, that of a similar pool in the lowest level. The resalts

were —

Depth, Temperature,

886 feet,

670 " 655

II. Obsebvationb made in Shafts kitheb just completed ob in

Pboobess.

1. Black Heth Nevo Shaft (1886).— This shaft, which was in prog- ress at the time of my observation, had Teaclied the depth of 880 feet. The water at the bottom, which collected rapidly, was de- rived in part from the small streams flowing? in from the adjacent rock, and partly from that which dripped from the edges of the higher strata. The temperature of the liquid in a small pool was 60°. That of the rock, as shown by a thermometer inserted deeply into a crevice on one side, was 61°.5. But the free access of moist- ure and air had no doubt depressed the temperature slightly, even in this position. Upon exposing the bulb to a stream of drops coming from some distance above, it indicated a temperature of 59°. It is therefore evident that the true temperature of the rock, at the bot- tom of this shaft, is somewhat over 61°.5.

Depth, Temperature, 380 feet, 61°.5

2. Midlothian New Shqft (1839).— This shaft cutting through a seam of coal 86 feet thick, penetrated a coarse grit for a few feet, and then struck into the sienitic floor. Immediately above and be-

neath the coal, and from the rock in contact with the sienite, nn- merooB small streams were flowing out into the shaft. In the low- est of these the thermometer was exposed nntil its temperature be- came stationary. The following was the accordant result of scTeral such observations:

Depth, Temperature,

780 feet, 6876

8. Midlothian New Shqft (1842).— This shaft, in the same field with the preceding, and near it, had at the time of ray observa- tions reacued the depth of 600 feet. Near the bottom it passed through a thin seam of coal and coal shale, in all about six feet, and beneath this to the bottom, a distance of about ten feet, it exposed dark argillaceous slates, the main mass of coal not havmg then been attained.

At a point 880 feet below the top of the shaft, a beautiful and rather bold spring issues from the sandstone, which is conducted downwards by a gutter cut in a spiral form around the shaft. The temperature of this stream, where it first appears, was carefully measured, and found to be 61°.75. At the bottom, numerous very small streams come in from the rock. These all agreed in giving the temperature 66°.25, wliich I therefore infer to be very nearly the temperature of the strata at that depth. The very copious drippings from above, together with the spring before noticed, blending with the infiltration from the strata near the bottom, formed a con- siderable pool, requiring the active use of the buckets. The tem- perature of this mixed water I found to be 68°.5.

At the time of these observations only two bands were at work in the shaft, and there had been no blasting for some time before I descended. I therefore consider the observations on the spring at 880 feet, and the small streams at the bottom, to be as accurate in- dications of tiie temperatures at those depths as this or perhaps any other method of examination admits of. We have therefore in this shaft —

Depth, Temperature.

830 feet, 6V,76

600 " 66°.26

The former of these results, it will be seen, is slightly above the temperature of the Black Heth new shaft, previously cited, though this shaft was fifty feet deeper. This difference is doubtless owing to the very large amount of cooler water which descended in drip- pings to the bottom of the Black Heth shaft, causing a decided re- duction of temperature in the rock, in which the thermometer was inserted.

Assuming 56°.75, the mean temperature of Shockoe hill, Rich- mond, as a sufficiently near approximation to that of tiie region of these mines, which is only about twelve miles from the city, the fol- lowing Tables will exhibit the results of my observations, together with the excess of the subterranean temperature, at each depth, over the average heat of the surface :

5Y3

Table I.— Obsebyations ts Mines in Opebation at the Time.

Greenhole Pit,

Mills and Keed's Pit,

ditto,

ditto. Black Heth Engine,. Wills and MicbaePs,.

ditto,

Exocm*

r.25

2*.75 4*.25 6'.25 6'. 25

Table II. — Obsebyationb in Shafts either just completed ob

IN Pboobess.

Black Heth, new shaft, Midlothian (spring),. . . ditto, (bottom), ditto, (deep),..

Depth.

Tempmtore.

880 feet. 880 " 780 "

or .5

61*.75 66'.26 68*.75

Ezom*.

4*.75

9*.50 12*

Making no deduction for the depth of the intariahle plane, the results embraced in the first table give, as the rate of increase of temperature with the depth, 1° for 74 feet.

Aseaming sixty feet for the deptb of this plane, a distance which, from the open and moist condition of the rocks, I think more likely to fall below than to exceed the truth, and calculating the ratio of increase beneath this point, I find it to be 1° for 62 feet.

Making like computations in reference to the second table, the results are —

1st. Estimated from the surface down, 1° to 66 feet.

2nd. Estimated from the invariable plane down, to 59 feet

Comparing the numbers deduced from the two classes of obser- vations together, it will be seen that the diminution of temperature in descending is slower in the mines in active operation than in recently opened shafts; so that, whatever may be the extraneous heating influences affecting the former, they are more than counter- balanced by the permanent cooling due to the descent into all parts of the mine of the cooler water from above.

Gompariug the three last observations in table second, the two former of which were made in the same shaft, and the last in one only a few hundred feet removed, there is ground for inferring that the rate at which the temperature increases grows less as the depth augments. In descending from 880 feet to 600, that is through 270 feet, the rise of temperature is 4°.5 ; while in descending from 600 to 780, or through 280 feet, the rise is only 2°.5. This difference would, I think, have been less, could I have obtained the tempera- ture at 780 feet free from the cooling influence of the copious drip- pings from above. Yet even with the most liberal allowance, there would still remain evidence of a diminishing rate of increase with

the depth, such as has already been remarked by Mr. Fox and other European observers.

OoDsidering the observations in the Midlothian shaft at 880 and 600 feet, as the ones most exempt from any known source of error, and deducing the rate of increase from them, I find the resalt to be almost precisely that inferred from table second, that is for every 60 feet.

I may therefore, I think, in conclusion, affirm as approximately true, for the region in which these mines are situated, that from the invafidble plane downwards for many hundred feet, the temperature augmentt at the rate o/V/or every 60 feet qf depth.

Connection

or

Theemal Springs

In

Virginia

With

Anticlinal Axes And Faults.

On the Connection of Thermal Springs m Virginia, WITH Anticlinal Axes and Faults.

Fbox nuxaAonoim or Tta AuooiATion of Amkbioax Qiologuts ahd Hatubal-

18Tb, 1840-1S42.

The proximity of somo of the noted Thermal Springs of Enrope to lines of remarkable disturbance in tlie stratification, appears to have been early noticed. Whitehurst long ago, in his Theory of the Earth, alluded to this peculiarity of geological position, when speaking of the waters of Matlock. In recent times similar ob- servations have been greatly multiplied. 6tifl% has made particu- lar mention of saddle-Siaped elevations of the strata, often accom- panied by fractures, as marking the position of the thermals of Nas- sau. Hoffman has described the waters of Pyrmont, as flowing out in a valley of elevation of a nearly circular form. Oonybeare and Bnckland have called attention to the remarkable didocation in the neighbourhood of the Bristol hot wells, and Lyell and Murchison have noticed similar phenomena in the vicinity of Aiz, in Provence; while Forbes has made known the important fact, that a large class of thermals in the Pyrenees, and probably elsewhere, flow out at the common boundary of the hypogene and stratified rocks.

Further instances of the association of thermal springs with dis- locations of the strata, and other marks of uplifting and intrusive action, are mentioned by Dr. Gardner in his valuable treatise on mineral and thermal springs, and still more lately by Dr. Daubeny, in his lucid and comprehensive report on the same subject to the British Association. To the latter distinguished geologist we are indebted for many interesting speculations founded on these and other peculiarities of thermal springs, viewed in their connection with the theory of volcanic agency, of which he has long been the ingenious and zealous advocate ; and to Professor Bischoff, of Bonn, we are under equal obligations for an elaborate and masterly analy- sis of the mechanical, geological and chemical conditions connected with the flow of such waters, together with an explanation of their temperature and impregnation, deduced from the theory of a gen- eral subterranean heat.

With the exception of brief and rather incidental notices pub-

lished by myself and others, and the communicatioDS of Dr. Daa- beny to SilUman's Journal and the Ashmolean Society, no account has yet been given of the peooliarities of geological stmctare, asso- ciated with the thermal springs of the United States. Indeed, the supposed rareness of their occorrence in this conntry, compared with many parts of Europe, and their comparatively slight excess of temperature in most instances over the ordinary springs, have naturally rendered them less inviting as subjects of observation. It is hoped, however, that the details about to be presented, by prov- ing their frequency in a part of the Appalachian chain, in which until of late years only a few were believed to exist, will encourage a search for them in other parts of this extended mountain belt.

My objects in the present communication are Jtrst to call atten- tion to the YQTjJrequent occurrence of thermal springs among the axes of the Appalachian chain in Virginia; secondly to indicate certain Iowm o/pasitiony by which I have found them to be governed, and thirdly to point out the important bearings of those facts when connected with the peculiar geology of the region, upon the theory of a generally diffused internal heat

According to the views of Professors Daubeny and Bischofl every spring is to be regarded as Thermal whose temperature ex- ceeds the atmospheric mean of the region in which it is situated : and in conformity with this definition, the former of these philoso- phers has proposed, in constructing a scale of temperature in re- gard to them, to cidculate it not by tiheir actual warmth, but by the degree of their excess above the mean of the climate." The pro- priety of this suggestion, which he has himself carried into execu- tion in the very valuable Table appended to his Report on Mineral and Thermal Waters,* is obvious upon a moments consideration. Thus we know, that the ordinary superficial springs under the equa- tor have a temperature as high as some of the ebrated thermal waters of Europe and America. In Mexico the temperature of sev- enty-two degrees, corresponding with the mean of the climate, be- longs to the common springs, while in Virginia the same temper- ature renders decidedly thermal the well Imown fountains of the Sweet Springs Valley, which rise in a region whose average is about fifty- one degrees.

Admitting that the elevated temperature, observed in mines and Artesian wells, is dependent upon a generally diffused internal heat, increasing with the depth, and not upon chemical or volcanic agen- cies of local operation, the class of thermal waters, as above de- scribed, ought to include a large proportion of such springs as are not of superficial origin. Indeed, under any view of the sources of their temperature, all springs ought to be included in this class whose heat is invariable, or when liable to change never sinks below the atmospheric mean of the place.'* Some decidedly thermal springs, as, for example the White Sulphur Springs of Virginia, display con- siderable variations of temperature with the change of seasons or ot

♦ Of course this is not intended to include springs originating in glaciers or neiu* tho tops of high mountuins.

weather. It would, therefore, not be correct to assnme permanency of heat as the criterion of thermal character, however completely, in the ordinary circumstances of springs, such permanency would seem to prove that the waters in which it is observed belong to the thermal class. It may be fairly assumed in general, that a spring presenting a uniform temperature, or one which, in its fluctuations, never descends below the atmospheric mean, cannot be dependent for its heat upon the atmosphere and superficial strata. Hence the general dissemination of such springs over a widely extended region, furnishes the strongest evidence for the existence qf a perennial source of heat vnthin the earth.

As remarked by Bischoff, the coldest springs of uniform temper- ature, provided they do not derive their waters from a neighboring mountain, will exhibit the nearest approximation to the average temperature of the country ; but will always be a little, though it may be a very little higher. Guided by these views, he has shown, from extensive observations in Germany and other parts of Europe, that thermal springs are of far more frequent occurrence than had been supposed, and indeed, that nearly all the copious mineral springs there, and probably, by inference in other parts of the continent, are of this denomination. Out of twenty mineral springs in the vicinity of the Lacher See, which he continued to observe at different sea- sons for several years, the coldest always exceeded the mean of the place by about two degrees and a quarter, thus proving them all to be unquestionably thermaL Similar observations on the springs of the Dippe, Jordan, Pader, and Heder, flowing from the foot of the chalk rocks of the Teutoburges-wald, brought to light the fact that out of sixty-six running fresh water springs, only three had a tem- perature below forty-seven and three quarters degrees, the mean of the place, making sixty -three to jbelong to the thermal class. In like manner Prof. Forbes found the temperature of a number of copious springs upon the Rhine, not before supposed to be thermal, to ex- ceed by several degrees the mean of the place.

Observations of these slightly thermal as well as of warmer springs, though thus numerous in some parts of Europe, have per- haps been too much confined to such regions as are known or may be supposed to have been at one time the theatre of local fwleanie ac- timty to admit of our inferring, with confidence, that the elevation of temperature thus observed, is the result of a generally pervasive heat within the earth. Indeed, the very frequent occurrence of in- trusive igneous masses, among the rocks of a large part of Europe, is calculated to weaken the force of such an inference generally, as applied to that portion of the earths crust.

In this country, the vast belt of mountains ocrupied by the Ap- palachian strata, presents, as I conceive, a region peculiarly favorable for unambigiwus observations of this class, in consequence of the absence, excepting along its eastern border, of trappean or other erupted rocks. It is therefore greatly to be regretted, that so little has been done towards an accurate determination of the temperature of the perennial springs of this region, more particularly of such as

are situated near conspicnons axes and lines of f aalt. From my own observations made from time to time daring the last eight years, chiefly in Virginia, I am led to conclude that a great proportion of the copious and constant springs of this belt, and more especially those of our great limestone vaJ&ey, are truly though slighuy ther- mal, and that they owe to a deep subterranean source the remarkable uniformity of temperature they exhibit. As, however, accurate de- terminations of the atmospheric mean, as well as minute observationa on the springs at various seasons, are requisite in deciding with cer- tainty upon their thermal character, and as we are yet very imper- fectly provided with these data, the question, with regard to a great number of our bold springs, must still remain unsettled. I therefore restrict myself in the present paper to a notice of such as are de- cidedly unequivocally thermal.

The following Tables comprise all the well-marked thermal Springs of Virginia, either previously known, or which have been brought to light by myself and my assistants, in the survey of the State.

Table I, relating principally to the thermab which are best known and most resorted to by invalids, includes, in regard to most of them, a statement of the names and relative quantities of the evolved gases, with the names of the gaseous and principal solid ingredients.

In Table II, these particulars are omitted, as being of less pres- ent interest with regard to most of the springs it embraces, but oc- casional notices are annexed of the evolved gases and of the contents of the waters. I may add, that a minute account of the ingredients of our thermal and minerd springs generally, derived from a long series of analyses in which I have been engaged for many years, wiu be made public in another form. It will be seen, that some of the springs, embraced in Table II, have a temperature but little above the atmospheric mean, yet their thermal character is believed to have been fully established by the permanency of this excess.

Oatalogue of the Thssmal Spbinob of Viboinia.

TahUL

S

Kamt of Sprfaif .

Warm SpringBy

1. Principal Bath,..,

2. Drinking Spring,.

Bci Springty

1. Gentleman's Boiler,.

2. Spout Bath,

6 I 8. Bed Spring,.

Gosnplilad podtkia.

Warm Spring Valley, Bath county,

Same valley as above, in Bath county, . . .

In anticlinal axis of formation 11. , of Va. and Pa. repoita,

In name axis as above,

Talble I. — Continued,

of SjiriBs*

4. Ploasure Bath,

5. Barrel Spring,

6. Sweet Spring,

7. Gents* Lower Spout, .

8. Ladies' Hot Spout,..

Gap Sprinffy

8w€d Alum 8pri7ig$..

12 1. Toothache Spring,. IB ! 2. Healing Spnng, . . .

14 8. Spring near Boad,.

15 FdlUng Spring

Sweet SpringSy

So

Si S2

S5

1. Drinking Spring near

hotel,

2. Old Bed Spring,

8. Bogers' Bed Spring,

or Champaigne

Spring, bbl

4. Bubbling Founttdn,.

5. Western Spring, . . . .

Snaie Bun Springe,.

1. Two large Spring, . .

2. Lea8,butColaSpnng8,

Balh Springe,*,,,

1. Spring near hotel,.

2. Southwest of (1),. 8. Southwest of (2), .

White Sulphur,.,,, Wileon'e Thermal,,

MeHnry*e Spring,.

N. W. of Warm Spring, on road to Bull Pasture,

8 miles S. W. Hot Springs,

Near Covington,.

Sweet Springs V allej, Alleghany county,.

Near N. E. end Sweet Springs Valley, . . .

Warm Spring Bidge, Bath, Morgan coun-

ty,

Greenbrier county,..

Near Long's Entry creek, Botetourt

Near N. fork of Hol- Bton river, Scott county,

In the above axis near N. W. termination of expos. For. XL

In above axis, For. II.

Near S. W. end of same

axis For. II. Anticlinal axis passmg

into fault N. W.

side of II.

In same axis, termina- tion of For. IL

S. £. flank of anticli- nal axis of Capon Mt. in For. VIL

In anticlinal axis of

For. VII. In antid. of For. VII.

N. W. of axis of

Biggs' Mt.

Near fault, bringing For. II. in con. with For. XI, in XL

For modem names see Appendix.

Oatalooub of thb Thermal SpsmoB of YntGrniA.

Table I. — Continued,

Ttnp. of

of

GkuM rrolTcd.

CtaMou lagndlcDU.

100 enbic iaehM oostaip

Total in 100 enbic lochM.

qiriog.

97*°

61'

2.6 f . i 1.62 Trace

10.64 gre. cone'iBt of Sul. Lime, S.Mag.

6. Soda, Carb. of

Lime.

(t

((

(t

(i

((

(1

u

t(

C. Magnesia, etc.

It

1.79 0.82 111.

Trace

18.25 giB. do., with

a decided amt of

carbonate of iron.

i(

- 1 tT n Qfl

12.78 grs. same. 15.61 gn. same.

it

84. 1 6 iii'l" i.'so o.'S

6: 102

87.5 0 12.5

102*

... iiso 6!2*

18.12 grs. same.

t(

..Jo 1ft A ftK

14.5 grs. same. 42.76 gTB. same. 18.8 grs. same. Chlorides of Sodinm, Calcium and Maff.

It

exist in all these

waters in small

amount; also very

faint traces of Io-

dine. The same

is true of those

which follow as

far as 26.

t(

Ig

Trace

82.67 jBTTB. main in- gredienta same as above.

t(

88.81 grs. same, with more Carb. iron.

lb

40.76 grB.same, with more Carb. Iron.

Trace

41.21 grs. same.

2a

52?

t(

tk

(t

"i.i

(1

t(

.

4.75 grs. chiefly Carb. Lime and

((

(i

ti

i(

u

((

Mag. and Sulph.

J

of same basis.

Table 1. —Continued.

rrtof.

z

Q-mtmH

—

'I

J

TultainaUclHbu.

2.0T

OS.M gm. Carb. of Lime and Mas.; Sxlph. Lime, Mag., and Soda cblondo of So- dium. Mnen. and CpJcium,&cn;Sul. Uyd. oi Magne- BiumjSulph.rron: a marked amt. of Iwlins. Sulphur

2fi.Mgra.Bame.

63t

1. Kndoaed Hprinii. 3. Open ipring. S. Open Bprinjj.

Gmtm or Ostnpon. 1. rrinaipalsprinic. S. Spring hlgh<

S. Spring

than (2). 4. Bpring higher

than (3).

KiDjiat Thrrmal.

Knijtra

In Bteep anticlinal axis of For. VI. Springs bold and constimt. Soma

N. W. Bide of anticlinal axis of hnddy'a Mt From verticiil gtrata of For. VII. Copious ond

S. E. aide of anticlinal of Kloh Patch Mt. From For. VI. CopiouBond

Anlidina! niB of North Kiver Ml. from For. VI. Verv bold and

SSi

TahU ILCantinued.

Tflinp.

of spring.

Tamp*

of pboa.

52?

Nam* of Spring.

PaaroM Spring,

Spring* near War- deneville.

Busby' 9 Spring,

Nap' tOreek Spring.

Walker't Valley Springe.

1. Larg:est npring.

2. Less Bprings.

Springe near Qdl- hratthe.

1. Lower spring.

2. Upper Bpring.

Springe. A great group of ther- mab covering nearly half an acre.

Kmherling epring

Edmonaone Big epring.

Limesione epring.

Limeetone Spring.

StruMer'e Spring

Buf&re Gap

Springe. 1 St Spring. 2d Spring. 8d Spring.

GcognUoal podlloB.

Near Peaice's iiimaoe, N. W. side of Paddy's Mt.

Hardy county.

W.ofWardens- ville, Uardy

Near Hunters- ville, Poca- hontas 00.

Valley of Walk- er's Creek, Wythe CO.

On Hunting Camp creek, near junc. with Wolf creek, Giles 00.

Rimberling fork, Giles co.

Near Koanoke river, Floyd(?)

Co.

Near east base of Little North Mt., Shenandoah

Near Afilford, Page CO.

Entrance of Stricklers Gap, Rook- bridge 00.

Ridfire,atBu- ford's gap, Bedford co.

OMloglnl poillkB.

N. W. side of anticlinal of Paddy's cove. Junction ofFor. VLandVIL

N.W. sido of anticlinal of Chestnut Bidge, from For. VU.

N. W. sideof anticl. of Big Sandy. From Junc. oi For. Vn. and VUL

AntlcL axis of Brown's Mt, For. VL Much gas, Nit. C. add.

Axis in For. 11. Bocks nearly verticaL Bold. Gas.

No gas.

Steep beds of For. IL Near fault of Draper's valley. Very bold springs. Gas.

Near N.£. end of anticL of Burk's Garden. From For. VIL

Anticl. of Little Flat Top Mt. For. VL

Fault in F. II. Copious. Much gsA, Nit., &C.

Inversion of For. II. on 111. with fault. Flows from IL Bold : no gas. Inverted axis of For. IL Very copious.

Inverted axis of For. IL Very copious.

Inversion of For. II. on III. with fault. Flows fh)m n. Bold. Nit., Ox., and C. acid.

S. E. of Blue Junction of For. I. with

Uypogene rocka.

58&

The details embraced in the preceding tables of our thermal springs, will, I think, Justify the assertion, that in no region hith- erto described is the connection of springs of this class with tibe structural features of the district in which they occur, so uniformly and extensively displayed as in our Appalachian belt. Hhefiftysix springs here enumerated embrace twetUy-Jha distinct lines and indi- viduid localities, situated in various and remote parts of the Valley, and the mountainous belt adjoining it on the northwest, making in all an area of about fifteen thousand square miles. Fortp-tix of these springs are situated on or adjacent to anticlinal axes, seven on or near lines of fault and inversion, and three the only group of this kind yet known in Virginia, close to the point of Junction of the Appslachian with the Hypogene rocks.

It may therefore be announced as the prevailing law as regards the more decided thermals of Virginia, and I have reason to be- lieve of other parts of the Appalachian belt, that they iaeue from the Unes qf anticlinal aae$, or from pointe very near weh lines,

A glance at the several short sections accompanying this paper, aided by the following brief comments, will serve more particularly to illustrate the conditions under which they thus generally occur, and to impart just conceptions of the structure of the districts in which they are situated.* (Plate No. 11.)

Bbotion L lYom the Warm Springs to the Little North Moun- tain.

Seotiok II. Passing through the Hot things,

SsGTioN III. Passing through the Gap J>ring and. Ebbing Spring,

Sbction IV. Through aads at Kayser's Springs,

In the first of these Sections are embraced three thermal locali- ties, presenting distinct geological conditions. In the most western, that of the weU known Warm Springs, the water comes to the sur- face in the line of an anticlinal axis. In the next, that at the Mill mountain, it flows out on the southeastern side of the axis, and in the third it issues from rocks presenting a great inversion, accom- panied by a fault.

Hie Warm Springs rise to the surface through fiisnres, in a mas- sive bluish limestone, a part of Formation II, of the Virginia and Pennsylvania Reports, and corresponding to the Black river lime- stone of the New York geologists. This rock forms the surface of a long and narrow anticlinal valley, extending from beyond the Gap Spring (Section III) to the neighbourhood of the Falling Spring (Table I, No. 16,) a distance of about thirty miles, nearly in a direc- tion from northeast to southwest Beyond tliis, towards the north- east, the higher formations close over the limestone, forming a lofty unbroken mountain, in the prolongation of which the axis gradually dies out. A similar though more rapid change terminates the axis at the southwest, its entire length being about siity miles.

The rocks on the northwest side of this axis, forming the Little Warm Spring mountain, are in general either vertical or overturned,

The scale of the Sections ifl 21 miled to the inch or twice that of the large State map. The eastern part of Sec VIII is by mistake, too much expandecL

while those on the sontheast, constitating the lofty and massive range of Wartn Spring mountain proper, present a moderate sontheast- em dip, excepting at a few points where the inclination for a short distance is much steeper.* The line of thermals situated in this axis, includes those of Table I, from 1 to 16 inclnsive. Of these, the least thermal, the Gap Spring and Falling Spring, are found to- wards the extremities of the anticlinal valley ; those nearer the cen- tre of its length, the Warm Springs and Sweet Alum Springs, have a much higher temperature, and the Hot Springs, occupying a central position, are the warmest of all. At the latter point the flexure of the strata appears to have attained its maximum, and is of the folded kind, the rocks of the northwest side of the valley, and of the Little Warm Spring mountain, being inverted for a thick- ness of about three thousand feet.

The amount of water issuing from these springs is so great as to form the chief part of the Warm Spring creek. Cedar creek, and other streams flowing out of the valley towards the northwest At all these points nmch gaseous matter is evolved along with the water, consisting in great part of nitrogen, with some carbonic acid, a very little and in certain cases no oxygen, and at two or three points a slight admixture of sulphureted hydrogen.

The position of this valley between two lofty ridges, which uniting at its opposite extremes form a complete enclosure around it, and the steep inclination of the strata along the western part of its surface, are just such conditions as might be expected to give rise to a large accumulation of water at great depth, and to furnish a hydrostatic force capable of raising it to the surface. It appears to me, therefore, that in speculating upon the mechanical agencies concerned in the emissions of these thermals, we are not called upon to imagine any other force than that of the simple pressure of aqueous columns, either continuous or interrupted by gases accumu- lated in the same fissures or cavities within the earth. Nor in trac- ing to their origin the temperature, evolved gases, and the chemical ingredients of these waters, do I conceive that any further condi- tions are required, than the access of the air and meteoric waters to rocky masses at a great depth below the surface, and whose temper- ature, due to that depth, sustains the chemical actions necessary to give the proper impregnation to the springs.

In glancing the eye along Section I, it will be seen that the flexures of the strata are such as to give the axis-planes an oblique position, dipping towards the southeast; a structure equally distinct also in the other sections, and which is in conformity with a general law, already announced by my brother. Prof. H. D, Rogers and my- self in a joint paper On the Structure of the Appalachian Chain read to the Association.! In consequence of such a flexure, the

This unusually Bteep inclination on the southeaet side of the axis, is seen opposite the Warm Spring on the main road.

t To this paper, and the accompanying Sections and Diagrams I would refer for a full exposition of this law, and for explanations of the terms normal and folded JUxurea, axii-planesy &c., used in the present article.

strata of the Mill monntain, on the western side, are thrown into an inverted position; those on the east, in which tne Thermal/ Pan- iher Gap rises, preserving a moderate dip towards the southeast. This bold spring, accompanied by a good deal of gas, chiefly nitro* gen. issues from beds of limestone belonging to onr For. VI, nearly equivalent to the Pentamerns limestone of New York.

The same conditions accompany the group of thermals marked on Section IV. The strata here are more slightly inverted on the northwest, and their ctirvature is so well preserved, even in the massive beds of sandstone, (For. IV, Shawangnnk grit of New York,) as to present, in the grand exposure at Clifton forge, a vast rocky arch of more than half a mile in span.

The thermal at the southeastern extremity of Section I, is asso- ciated with a different structure. The limestone (For. II) of the great Valley is here, as in most places near the foot of the Little North mountain, thrown over upon For. IIL This inversion, due to a folded axis lying parallel to and southeast of that ridge, though it often extends entirely through the mountain, at this point ceases with the eastern outcrop of the lower beds of For. IV. At the junction of Formations II and III, the latter is much crushed, and a slight fault occurs. It is near this spot, in the limestone, that the warm waters make their escape. The thermal, marked at the southeastern extremity of Section X, occurs under precisely the same conditions, rising in the same rocks, thrown into the same inverted attitude.

Section V. Across the Sweet Spring Valley,

The structure of this valley, like that of the Warm Springs, is due to a great anticlinal axis. Commencing at a point south west- wu of the termination of the latter, this valley extends for about fifteen miles in a nearly west-southwest direction, bounded by the Sweet Spring or Peters's Mountain on the southeast, and by the Snake Run or Little Mountain on the opposite side. Where the limestone. For. II, begins to be exposed by the opening of a great anticlinal range of For. Ill and IV, and for a short distance towards the southwest, the strata have a normal flexure those on the north- west side of the axis dipping steeply towards the northwest. But as we proceed towards the southwest, the flexure increasing, causes an inversion of the strata on the northwest side, accompanied by an occasional crushing and partial concealment of the slate rocks of For. III. These conditions, first seen at the group of thermals on Snake Run, (Table I, Nos. 21, 22,) continue, with some fluctuations, to near the southwest end of the valley, the amount of dislocation gradually but irregularly auirmenting as we trace the Little Moun- tain in that direction. Beyond this point the fault rapidly increases, so that in the distance of a few miles not only the rocks of the Littie Mountain, bnt all the strata intervening between For. II, and For. XI, (carboniferous limestone) have been swallowed up. In this condition, occasionally varied by the intrusion of in- wedged

knobs or masses of the ingulfed strata, we may trace this extraor- dinary dislocation along the northwest base of the Peteri's and East River mountains for more than fifty miles, after which it is still fnrther continued with a new topography.

The Sweet Springs flow out from the steep-dipping and inverted limestone near the centre of the valley ; the Med Springe and Snake Bun group from points nearer the junction of this rook with For. Ill, of the Little Mountain. The streams fed by these copions foun- tains, flowing towards the northwest by narrow transverse valleys through the Little and Snake Run mountains, have accumulated a great thickness of tufaceous deposit, forming in the neighborhood of the Red Springs a succession of picturesque cascades.

Gas, consisting of nitrogen with a considerable amount of car- bonic acid, escapes freely from all these springs, rising from the Sweet Springs m- copious streams. Much dissolved carbonic acid is also present, rendering most of these waters decidedly acidulous, and enabling them to retain in solution a marked proportion of car- bonate of iron, as well as the more usual ingredients, carbonates of Uine and magnesia.*

Sbotion VI. Through the White Sulphur Springe,

The axis in which the White Sulphur Springs arise, and that of the thermal of Browns mountain, (Table II, No. 43,) are nearly though not exactly in the same line. They are further from the southeastern margin of the Appalachian belt than any others re- ferred to in the tables, their distance from the Blue ridge, in a direct transverse line, being about forty miles. The White Sulphur axis, exposing For. VII, at the springs, dies out in a short distance towards the southwest ; but, traced in the opposite direction, ex- pands into a considerable rid go, bringing into view the upper part of For. VII, here of considerable thickness, and eventually terminates in a roll of the slates of For. VIII, near Anthony's creek. In the neighborhood of the springs the flexure of the strata is remarkably abrupt, the gentle slope on the southeastern passing into a verticid or slightly inverted dip on the opposite side of the axis. With the exception of this and another adjacent but very inconsiderable line of exposures, the sur&ce for many miles on either side is occupied by the slates and sandstones of Fors. VIII and IX, bent and con- torted by numerous lesser axes, and in the Allegheny Moantain and the numerous adjoining hills, carved by denudation into a variety of picturesque forms.

The winters of the White Sulphur are copious, but accompanied by very little evolved gas. The few bubbles I have succeeded in entrapping, proved to be nearly all nitrogen, but it is uncertain whether they arose with the water from the depths below, or were developed in the basin of the spring.

Though decidedly thermal, these waters have a fluctuating tem-

These are the only decidedly ncidulous springs in Virginia, and I believe in the (J. S., excepting a few which, like Saratoga, contain also a large amount of chloride of sodium.

peratnre, never, however, as I think, approaching nearer than ten degrees to the atmospheric mean.*

They form the only instance within my knowledge of a strongly snlphnreoas and at the same time thermal water in the United States ; and in these respects bear a close analogy to certain thermals of the Fyrenee8.t

Section YII. Through Wilson'* Thermal and across Garden Mountain,

This section includes a partial view of the great anticlinal of the Garden Mountain, exhibiting a striking example of the folded form of flexure, with an extensive inversion on the northwest side. Be- hind this, towards the northwest, lies the aotidinal of Biggss Moun- tain, separated from the former by an irregular trough of folded slates (For. VIII); and at the western base of Biggss Mountain occurs the lesser axis, in which the thermal here referred to rises to the surface. While the axis of Biggss Mountain brings up the whole thickness of For. JII, doubled upon itself that of Biggs s Mountain exposes no strata lower than For. Y, (Medina sandstone and Clin-

Dr. Daubeiiy, who viBited theae Bprings when in this oountry, did not advert to their bg thermal. See SilhmairB Journal, April, 1889.

t The plumose, Jilamentotu growth, involving a lai amount of hrdrated sulphur, which lines the boain and outlet of those waters, and which n-om its color has given rise to the name of White Sulphur, is alao found in other sulphureous spring in the State, and has caused the adoption of this name as descriptive or such springs as a eUutj notwithstanding their want of agree- ment m other and far more important particulars. Organic products ox an- other kind, developed in the enclosures of the Red, Blue, Gray, Crimson and Green Sulphur SpringSj and whoso true nature was also first suggested by mv- self, (see Hare's Chemistry, 1888,) have by a like connection originated tne names by which these springs are respectively known. Observations beyond, as well as in the State, have satisfied me that similar orcranio products are to be met wiUi, in Bome one or more forms, in all tha tulpKurtow waters of the Appalachian beltj and that they vie peculiar to waters of this class. Having read with great mterest Dr. Lankester's notice of the plants and animals found in the sulphureous waters in Yorkshire,*' as given in the Report of the British Association for 1840, I have been much gratified at finding these opinions corroborated by the observations of that eontleraan in regard to the sulphureous waters of Harrowgate, Askema, ana the neighboring district, ana I have enjoyed no little surprise in recognizing in tnc conferva which at those places collects in large quantities around the sides of the wells," and in the animal deposit. varying from a light pink to a rose color,'' the objects which impart sucii beauty to some of our celebrated sulphureous springs, and which six years ago I pronounced to bo of vegeto-animal " ori-

the collecting

the liquid in an adjoining cavity in the dark sulphureous mud--and I re- marked that hore the material of the rosy film collected on the surface be- neath, it continued diffused in the liquid for some time like a faint pink cloud, changing its position and its density. This, with other observations, sug- gest tne idea of its heing due to animalculae, which under certain favorable conditions as to light, and perhaps temperature, quiescence, and the contact of particular substances, would always display themselves in our sulphureous waters. For tJie distinct determination of the forms and relations of these or ganic objects by the microscope, we owe our thanks to Dr. Lankester.

ton group of New York,) over which the beds of VI and VII are seen bending in rather steep normal flexure, to be again elevated in part in the low ridge of VII, (Oriskany sandstone of New York,) rrom which the thermal issues. The point of exit of the waters is in nearly vertical strata, a little west of the axis-plane. Beyond this, towards the northwest, is a wide expanse of For. VIII, greatly folded and contorted, in which, at no great distance from the ther- mal, occurs Dibbrell*6 Spring, a cold alkalino-sulphureous water, such as characUrisM the lower and more calcareous portion of these slaty rocks.

The discharge of water at Wilsons thermal is abnndant, but is accompanied by very little gas. The spring contains a small amount of uncombined carbonic acid, together with a considerable propor- tion of saline matter.

Section VIII. From Bath acro%a the Cacapon Mountain.

The Cacapon or Capon mountain, formed by the union of several contiguous parallel axes, which arise at various points within a distance of fifty miles from the Potomac river, attains its greatest altitude and breadth about eighteen miles soathwestward of the line of ou,r Section, beyond which, in its prolongation towards the river, it gradually declines. Where most largely developed, a slight roll of the strata makes its appearance near its southeastern base, which soon assum- ing more importance, forms the distinct anticlinal of Warm Spring Kidge. This, in its prolongation towards the northwest, gradually loses its anticlinal character by the obliteration of the narrow trough between it and the Cacapon axis, and forms at the Potomac a low flanking hill of southeast dipping rocks. Where the tbermals of Bath arise, the anticlinal flexure is still in part preserved in a sharp but transient change of dip in the rocks a little westward of the Springs. Owing to an error in reducing this Section, the space be- tween the centre of the Eastern Cacapon axis and the position of the springs is much too great. Contracting this interval, it will appear that the position of these tbermals agrees in all important

Soints with that of the springs on the southeastern flank of the Mill [ountain, Section I, and of the group in Section IV.

These copious springs make their appearance near the junction of Fors. VII and VIII, at the southeostern base of the Warm Spring Ridge, here faced by the massive jointed sandstone of the former. The gas which accompanies the water, though consisting mainly of nitrogen, contains a rather larger proportion of oxygen than is found in the other principal tbermals of the State. The amount of solid matters present in these waters is extremely small.

Section IX. From the Caca'pon Springs to the Little North Mountain,

Section X. From the Great North to the Little North Moun- tain through Bond Springs,

In the former of these Sections, we have a view of the folded or inverted- form of flexure, both in the anticlinal of the Paddy and Great North Mountain, and in the trongh between the former and the Little North Mountain. In the narrow anticlinal valley hemmed

in by the wild and ragged heights of the Paddy and Great North monntains, no decidedly thermal springs have yet been discov- ered, thongh the stractore and topography of the place would seem highly favorable to their production. Perhaps their absence may be explained by peculiarly shattered condition of the strata oconpying the snrface of the valley, and forming the enclosing mountains, especially that on the northwest, in virtue of which ready channels may be furnished conveying them to other and re- mote points of discharge. This opinion is, I conceive, supported by the conditions under which the Gacapon Springs occur. These thermals, as indicated on the Section, make their appearance on the northwest side of the Great North Mountain. They are four in number, and situated at different levels, the lowest, which is also the warmest, flowing from For. YII, near its junction with YIJI, and the others successively lower in temperature and higher in position, issuing from VI and V. They are all copious and con- stant and yield but little gas. In the lower or principal spring, the chief ingredients are carbonates and sulphates of lime and mag- nesia, and sulphate of soda.

Seotion a, parallel to the preceding, and a few miles north- eastward of it, includes, it will be seen, three separate localities of thermal springs, the first or Pearce's Spring, (Table II, No. 40,) at the western base of the Great North Mountain, the second or Bond Springs, (Nos. 29, 30, 81,) in the Cedar Creek Valley, and the third, an unnamed spring, (No. 51,) rising near the eastern base of the Little North Mountain, all comprised in a distance which, in a di- rect line, is less than six miles.

On comparing the two Sections it will be seen, that the anticlinal valley of the Paddy and Great North mountains contracts towards the northeast, the inversion on its northwestern side being at the same time replaced by steep northwestern dips. This change goes on augmenting, until, at no great distance northeast of the present section, the valley terminates in a great anticlinal mountain of nor- mal flexure, formed by the now united rocks of the Paddy and Great North mountains. While this change is in progress, two stnaU axes, commencing a little northeastwards of Section IX, make their appearance in the Cedar Creek Valley, lifting For. VII and then VI, from beneath the slate, and forming the low range called the Sugar Hills. It is on the more important of these axes, that the Bond Springs are situated. This is a sharp anticlinal, giving exit to the water through For. VI. The spring to the east of this flows from the limestone through For. VI. The spring to the east of this flows from the limestone near the southeastern base of the Little North Mountain, i&suing as before noticed from a line of inversion and fault. Pearees thermal agrees in position, as regards the axis, with the Cacapon Springs, rising near the junction of steep- dipping VI and VII.

All these springs evolve more or less gas, chiefly nitrogen, and the Bond Springs contain a considerable amount of calcareous and magnesian salts.

Deeming tlie nrecediDg details sufficient to illustrate the oondi- tioDS under which the varioas classes of thermals in Virginia pre- sent themselves, it would be unneoessary, as well as tiresome, to enumerate similar particulars in regard to' the numerous other warm springs referred to in the preceding tables. I may here, however, remark, that but few of our thermals, not flowing in axes, rise, as in the case of the Mill Mountain and Eajser's Springs, on the iouth ecutern Me of the axis plane. Indeed, out of the whole number included in the tables, I know of but three groups so situated, and these are exhibited on the sections. All the othen ieme from the eteep-dipping or inverted strata on the northweet eide qf the aniieli' nah, and this may be laid down as the general law of their poei- tion.

Of the mechanical and ehetnieal agencies concerned in the pro- duction of some of these thermal springs, I have already briefly expressed my views, while describing the structure of the Warm Springs Valley, and its enclosing mountains; and I need hardly add, that the same general explanation is equally applicable to the other thermals, situated in anticlinal valleys. In carrying out this view more in detail, and especially in applying it to cases like that of the Sweet Springs VaUey, where the anticlinal axis passes into a pro- longed line of fault, it has appeared to roe to be necessary as well as reasonable to adiiiit Jiretj that the subterranean channels which operate both in furnishing the requisite supplies of water and air to the depths below, and in forwarding the thermal stream under hydro- static pressure, must have a direction conforming in general to the strike of the rocks ; and secondly that the direction of the down- ward flow of the meteoric waters, is in a great degree determined by the natural partings of the strata, or, in other words, by the plane of dip.

These conditions granted, it will at once appear, that in a doted anticlinal valley, like that of the warm and hot springs, thermals, if occurring at all, might be expected to appear along its whole length, in a linear arrangement, and near its western boundary. It would also seem, in this case, that the height of the comparatively ele- vated ground at the two ends of the valley would determine the hydrostatic column employed in bringing the water to the surface.

Where, however, the valley is dosed only at one endj as in that of the Sweet Springs, the case is, I think, different Thermals may of course be looked for towards the closed end, and in this position they are found; but it is a remarkable fact, that the line of fault constituting the prolongation of the axis of the Sweet Springs, though continued to a distance of more than fifty miles, does not disclose a single thermal throughout its whole extent, nor have I yet succeeded in discovering more than one spring of the kind, in other parts of the Appalachian chain, where similar geological conditions prevail. On the other hand, in the prolonged lino of fault running along the southeastern base of the Little North Mountain, close to the northwestern margin of our great Limestone Valley, and at other points, where the same structure exists, many thermals have

been detected, seyeral of which, from their marked elevation of tem- perature, are included in the preceding catalogae.

These resalts are, I think, sufficiently explained by reverting to the two conditions above specified, in connection with the form of the surface, and the position of the strata in the vicinity of these faults. In the first case, where For. II rests upon the overturned beds of For. XI, the strata composing the narrow belt of the former, along the northwest base of the great range of Peterss and East River Mountain, and southeast of the line of faillt, as well as the rocks of these ridges, dip at a moderate angle towards the southeast, and therefore away from the fault. On the opposite, or northwestern side of the fault, the country is comparatively letel the Little Moun- tain, which formed the western boundary of the Sweet Springs Val- ley having been ingulfed in the vast hiatus. Hence, tnough the rocks of XI, for a short distance northwest of the dislocation, (through the breadth over which this formation continues inverted,) actually dip towards the fault, the flat topography on the northwest is not such as naturally affords a hydrostatic column sufficient to raise the water from a great depth to the surface, along the line of fracture. Nor could we expect the heights of Peterss Mountain on tiie southeast to furnish such a column, since the southeast dip of the strata there would rather appose than facilitate the passage of the liquid towards the fault, and would most probably convey it to sub- terranean tracts lying towards the southeast. There is also another feature, to which, as I conceive, some influence is to be ascribed in preventing the occurrence of thermals along this line. The strata of For. XI, although overturned where they are in contact with For. II, continue in this position across but a narrovo belt towards the northwest, and by a rapid curvature below are soon brought into a very gentle northwest dip, or into a horizontal attitude. Their up- turned edges could receive directly from the atmosphere but small supplies, and these, most probably, in part at least, would be con- veyed away towards the graduaUy declining level on the north- west.

Turning now to the second ease of which we have an example in the fault adjacent to the southeastern base of the Little North Mountain, we at once discern this important difference, that while the direction of the dip and inversion is the same as in the preced- ing, the high grounds of the Little North Mountain lie to the north- west. Hence the downward drainage between the strata on the flank of this ridge, conforming to the southeastern dip of the rocks, must be towa/rds the faulty and the hydrostatic columns communicat- ing with the heights, and following the plane of dip, will in many cases have sufficient power to force up the heated water to the sur- face, at certain points along or near this line.

The numerous class of thermals whose point of issue is exterior to the bounding ridges of an anticlinal valley, owe their origin, as I conceive, to the same general agencies as have been above con- sidered. Bearing in mind, that in the great majority of cases they flow out from the northwestern boundary, the vertical or inverted

rocks of which are greatly shattered, and that their point of exit is generally hehw the level of the valley, it is reasonable to suppose that, in many instances, they have been conveyed away from be- neath the surface of the valley, when, in a less fissured condition of the strata towards the northwest, they woald have been forced to rise at some point within its confines. In many cases too, the downward drainage of the northwestern ridge itself is fully ade- quate to carry the requisite amount of fluid to the seat of heating and chemical action, and by hydrostatic power, to raise it again to the surface at a much lower level.

In speculating with regard to those therm als which issue at or near the base of a continuous anticlinal mountain, it is important to bear in mind, that while cracks and partings are found generally attendant upon flexures of the strata, these openings are by far the most numerous and extensive in that part of the curve where the change of direction is most abrupt. Hence they will be found de- scending in the interior of the mountain, much in the direction of the axis plane, and will He nearer to the northwestern than the south- eastern side. The meteoric waters supplied through these channels will find an exit either by the natural slope of the gently dipping rocks on the southeast of the anticlinal, or through the fissures of the shattered and steeply inclined or inverted strata on the northwest. Where but little of this fissuring occurs on the northwest side, they would meet with least obstruction by flowing in the opposite course, and might therefore, be looked for on the southeast. Such would seem to be the case with the thermals of the Mill Mountain and Kaysers, (Sections I and lY,) where the steeply inclined strata are comparatively entire. But, as formerly remarked, the usual posi- tion of thermals is on the opposite side of the anticlinal axes.

It may here be added, that where such springs present a tem- perature but little above the atmospheric mean, it is unnecessary, in accounting for their heat, to suppose that the water has been conveyed to any very considerable depth below the base of the mountain, as the subterranean line of equal temperature (chthon- isothermal line), deflected upwards by a massive and steep anti- clinal range, would come nearer to the general surface.

Such is a sketch of the views to which I have been led in con- sidering the positions occupied by our thermals, in connection with the probable mechanical agencies by which their waters are ac- cumulated and brought to the surface. Though in some degree hy- pothetical, as must be all attempts at explaining the unseen mechan- ism of nature, they are, I think, in harmony with observation, and at all events possess the merit of agreeing in general principles with doctrines sanctioned by the authority of such names as JiTBgo and Bischoff.

As regards the evolved gases and the ehemieal ingredients of these springs, my opinions, like those of others who have speculated on tnis subject, are, confessedly, far from satisfactory. While I am inclined, in some respects, to agree with the views which have been BO ably advocated by Dr. Daubeny, in relation to the origin of the

gases and other matters associated with thermal waters, I am by no means prepared to adopt the hypothesis that such impregnations are chiefly due to the chemical action of the metallic ha of the alkalies and ea/rths ; much less can I accede to the opinion, that the heat of our thermals, as well as that of the rocks from which it is directly derived, is due to what is usually termed volcanic action.

Deferring my objections to these views to a later head, I would venture to throw out a suggestion as regards the evolution of nitro- gen from these and other thermals, which appears to me not un- worthy of consideration. Admitting, with Dr. Daubeny, what I think extremely probable, that thi gas, as it appears in thermals, is hxASkVeeiduum of the atmospheric air which, conveyed from the sur- face to the source of heat below, has there been partially or entirely deprived of its oxygen, I would inquire, whether the composition of the rocky beds through which the atmosphere is thus conducted is not itself capable of explaining the result.

The lijnestone For. IT, and the slates forming a part of For. I, always contain more or less protoxide of iron and carbonaceous matter, even after long exposure to the action of the weather. Where freshly taken from a new excavation at some depth, the lat- ter rocks abound in the protoxide, and the limestone exhibits nearly all its iron in that stage of oxidation. It would therefore seem probable, that these and tlie other strata deposited beneath the Ap- palachian sea, contain, at great depths, this oxide to the exclusion of the sesquioxide. Looking to the large accumulation of the latter in a hydrated state, segregated in various parts of these several for- mations, it is not unreasonable to infer an even greater proportion of the protoxide in the deeply buried strata than would correspond to the whole quantity of iron combined in the rock above. That the presence of diffused organic matter, such as we know to have been deposited with the other materials of the strata, would se- cure the protoxide from further oxidation, while still in contact with the waters of our great Appalachian ocean, is a result in harmony with what we witness in our present seas, and with the known chemical relations of the substances concerned. Conceding, then, the existence of the protoxide in due proportion to these older formations, and imagining the air to obtain access to these strata at a depth at which the temperature is sufficiently hih to cause a rapid absorption of the oxygen by the protoxide, we should have a large amount of the residuary nitrogen evolved. The cai'bonaceous matter also would help to rob the air of oxygen and aid in the pro- duction of the carbonic acid, by which the nitrogen is uniformly accompanied, although it is to the calcination of calcareous rocks

Quickly volatilized and combined with ojsen, its power to arrest the oxidation of 'the protoxide, or to reduce the roxidB when rormed, would not. I oonoeive, be called into piay . But even if it were, the difficulty would not oe 8o great as where potassium and sodium are regarded aa among the chief oxi- dizing agents. For in this latter cafte, what becomes of any carbonic acid which, evolved at the focus of activity, is brought in contact with these metals ?

that, in common with others, I would refer most of the carbonic acid which oar thermal waters contain.

The conjectures thus thrown out, though, as I think, not entirely useless, are offered with that distrust which must always attach to speculations that cannot be brought to the touchstone of actual ob- servation, and more especially, too, from the fact, that they do not appear to have suggested themselves with any force to the able

Enilosophers who have investigated this subject. That I may not e misconceived, I here beg to remark, that I have no disposition to deny the hypothesis of the metallic bases, as applied to volcanoes, or even to some thermal springs. On the other hand, I would adopt it, as a part of the general theory qf the causes concerned in the for- mation of the early crust of the globe from a molten, and chiefly metallic mass. But, in ihi$ later stage in the history of our earth, I would venture to doubt the propriety of resorting to it in explaining the phenomena of thermal waters in general, and more particularly of those to which my own observations have been directed ; and I would give a hearty welcome to any theory which, dispensing with the necessity of penetrating to such enormous depths m dearch of the unoxidated metals, would explain the chemical characters of these waters by the known properties qf the roeks in connection with a generally diffused internal heat.

In consideriog the bearing of the preceding details respecting the thermals of Virginia upon the doctrine of a general subterranean heat, as compared with that of local foci of volcanic action, there is one fact in the geology of our Appalachian region, particularly de- serving of attention. I mean, the (dtnost entire ahseneey over its eaU surface of igneous or tolcanie rocks. These occur at only four or five points, without any observable relation to axes, and away from the neighborhood of any known thermals, and are in such small amount as together not to cover an area of more than ten acres. Add to the preceding this further fact, that our thermals are not confined to particular lines or axes, but are scattered at remote points oter the whole region and it will at once appear, with how mndi more reason they may be referred to a pervasive subterranean beat, than to points or lines of volcanic action. To apply the latter explanation, we must ve to these local foci a diffusion beneath the surface, which would, in fact, amount to abandoning the doctrine of merely local heating action, and admitting that of a general internal heat ; while, in adopting this latter, we see in the peculiar positions of our thermals in reference to axes, simply those mechanical condi- tions which fanor the access of air and water to the deep-seated and there/ore hot strata in the interior and their expulnon at the twr/ace.

Adopting the language used by the eminently philosophic Phil- lips, when referring to arguments urged in faor of the hypothesis of local volcanic action, as the cause of thermal springs in general, I would say, " These arguments, when taken in connection, appear to us to prove, that the heat of the springs is derived from the depths of the Channels in which they fiow below the surface," and " it seems

mmeceasary to appeal to local volcanic excitement for an effect which spreada, both in time and area, far beyond the traces of purely volcanic phenomena." Such being the inferences of one of the ablest of geologists, from a comparison of the chemical and geologi- cal relations of the thermals of the old world, with what augmented force may they not be reiterated, after the preceding developement of these relations in a region which, like oar Appalachian cnain, is almost destitute of even a trace of proper volcanic action I

The Physical Structure

Of Thb

Appalachian Chain".

On the Physical Stbuctube of the Appalachian Chain, as exemplifyino the Laws which have

BEGULATED THE ElEYATION OF GbEAT MoUNTAJN

Chains generally. By W. B. Rogebs and H. D.

' Kogebs.

Fkom TBAKSAcmoirs of trs Assooiatton or Amcsican Gbolooistc aivd Natitbai ms, 1640-1842. Illv8TKAtu> bt Platvs Noa. Ill, IV, and T.

Hating, in the prosecution of the State Geological Surveys of New Jersey, Pennsylvaniaf and Virginia, arrived at certain general &cts in the structure of the Appalachian chain, involving some new considerations in Geological I)ynamics, we propose, in the present memoir, to offer a description and thQory of the phenomena. As similar structural features would appear, upon comparison, to pre- vail in many of the disturbed regions of other countries, and among strata of all geological dates, an exposition of their laws cannot be uninteresting at this time, when every question connected with the elevation of the earths crust, is receiving so generally the attention of geologists.

To render our details intelligible in the absence of a geological map, we must first enter upon a brief geographical description of the extensive zone of country where these structural conditions exist. Such a preliminary sketch is the more essential, since in no region yet described, does the topography or physical relief of the surface, afford as accurate an index to the positions and relations of the strata, and to the movements by which they have been uplifted.

The Appalachian chain rises in the form of a broad belt of mountain ridges east of the St. Lawrence, in the northern part of New England, and taking a southwesterly course, terminates in Alabama. Its total length is about one thousand three hundred miles, and its greatest breadth about one hundred, if we exclude from this description the high insulated tracts of the White Moun- tains in New Hampshire, and that west of Lake Ohamplain, in New York. From the northern border of Vermont, the main chain gradually expands in width to the region of the Juniata and Poto- mac rivers, beyond which, in its progress to the southwest, it slowly and steadily contracts to its termination. While the great chains of many countries contain a principal central mountain axis, to which all the minor ranges more or less conform, this system con-

sists of a broad zone of almost innamerable parallel ridges of nearly equal average height. These seldom reach an elevation of four thousand feet above the sea; nor, if we except the great eastern range, the Blue Kidge, do they often rise more than two thousand feet from the level of the adjoining valleys, the more usual height being from eight hundred to one thousand five hundred feet. The general plain, supporting this broad mountain belt, gradually de- clines in level from the head waters of the Holston and Clinch rivers, in Virginia, towards both extremities.

The characteristic features of the Appalachian ridges, are their great length, narrowness, and steepness ; the evenness'of their sum- mits, and their remarkable parallelism. Many of them are ahnoel perfectly straight for a distance of more than fifty miles ; and this feature, combined with their steep slopes, and sharp, level summits, gives them the appearance, seen in perspective, of so many colossal entrenchments. Some groups of them are curved, but the outlines of all are marked by soft transitions and an astonislung degree of regularity. It is rather the number and great length of the ridges, and the magnitude of the belt which they constitute, than their individual grandeur or height, that places this chain among the great mountain systems of the globe. From the latitude of the Mo- hawk river in New York, to the northern boundary of Alabama, the chain in general consists of four parallel belts, the separate fea- tures of which it is convenient we should define.

1. The first or sontheastem subdivision is the relatively narrow, undulating mountain range, which in Vermont, is called the Green mountains, in New York the Highlands, in Pennsylvania the South Mountain, in Virginia the Blue Ridge, and in North Carolina and Tennessee the Smoky or Unaka mountains. This is rather a zone of closely united ridges, than one great mountain axis, though the latter is somewhat its character in Virginia, North Carolina, nnd Tennessee, in which States it has its greatest breadth and elevation. The average width of this belt may be stated at about fifteen miles, and its height, which is more variable than that of any other por- tion of the general chain, undulates between about one thousand and ve thousand feet above the sea.

The rocks of this tract consist for the most part of the older metaroorphic strata, including gneiss, and micaceous, chloritic, talcose, and argillaceous schists, together with masses referable to the earliest Appalachian formations, sometimes in a highly altered condition. Throughout nearly the whole distance, from Tennes- see to the Susquehanna, these latter rocks occupy the northwest* ern slope of the main ridge, and form the ranges of hills, sometimes of great height, flanking it on the northwest ; while in Pennsylvania, New Jersey, Massachusetts, and Vermont, besides presenting them- selves in this position, they form narrow belts and ridges among the older metamorphic strata towards the southeast.

Innumerable dykes and veins of all dimensions, and consisting of a vast variety of igneous materials, penetrate tliis belt, disturb- ing and altering its strata in a remarkable degree.

S. Immediately to the northwest of t)iis monntain range is a broad valley, which constitutes by itself a well-defined belt throngh- out the entire length of the chain, displaying a remarkable constancy in its structure and physical features. This, which we shall call the Great Appalachian Valley ranges from Vermont to Alabama, under various local names, being known in New York as the Valley of Lake Cham plain and the Hudson river, in Pennsylvania as the Kit- tatinny or Cumberland Valley, and further south successively, as the Great Valley of Virginia and the Valley of East Tennessee. Its average breadth throughout, is about fifteen miles, forming an un- broken and nearly level plain, except in Virginia and eastern Ten- nessee, where several long insniated ridges rising in it, separate it for a greater or less distance into two or more narrow parallel val- leys. Tlie stratification everywhere in this great belt is exceedingly disturbed, the rocks consisting principally of the three lower Appa- lachian formations, being, only in a very few instances, invaded, however, by igneous dykes.

S. Beyond the Oreat Appalachian Valley on the northwest, is a wide belt of long, narrow, parallel ridges, and included valleys, spreading northwestward to the foot of the great plateau of the Allegheny and Cumberland mountains. This, which we propose to call the Middle Mountain-helt has a breadth varying from thirty to sixty miles, its greatest expansion being in the curving region of the Juniata in Pennsylvania. It embraces all the Appalachian forma- tions to the coal inclusive.

4. The fourth or most northwestern of the belts into which we have divided the Appalachian chain, commences with the southeast- ern escarpment of tfie great table -land of the Catskill, Allegheny, and Cumberland mountains, and spreads northwestward with a gen- tle declivity, as far as the limits of the lant feeble axes of elevation. The average breadth of this belt, measured from the southeastern es- carpment of the plateau, to the plain which bounds it on the north- west may be stated at about thirty-five miles. This portion of the chain embraces all the upper Appalachian formations, including the whole of the carboniferous group.

Following the course of this great mountain bolt from Canada to Alabama, it will be seen to consist of a series of nine straight and curved portions in alternate succession, distinguished from one another by important topographical features, as well as by pecul- iarities of geological structure, and forming nine distinct ditieions,

1. Of these the first or Hudson Hiter Division extends from Canada to New Jersey, following the general course of the Hudson as far as the Highlands in New York, and comprising not only a large area in the eastern and northern parts of that State, but a considera- ble tract in western Vermont and Massachusetts. Along the great valley, from the northern port of Vermont to the passage of the Hudson throngh the Highlands, the strike of the rocks, and the di- rection of the axes, is about north fifteen degrees east, and south fifteen degrees west.

2. From where the Hudson crosses tlie Highlands, to the Lehigh

river in Pennsylvania, the whole chain hend gradnallj westward, taking a long regnlar sweep concave to the northwest. This por* tion of the chain we propose to call the Delaware DivisiorL

8. The next is a nearly straight part of the chain, extending from the Lehigh river to Cumberland county, in Pennsylvania, and may very properly be named the Susquehanna Division. Throngh- ont this tract the stnke is from east- northeast to west-south west.

4. To the southwest of the foregoing is the highly interesting curving portion of the chain, which we shall call the Juniata Di- vision. This diversified region extends from about twenty miles west of the Susquehanna, to nearly the same distance north of the State line of Maryland, and is characterized by a regular and very decided curvature, convex towards the northwest. The formations, in ranging between the above limits, change their strike from south seventy degrees west, to south thirty degrees west, undergoing thus a deviation in their course of forty degrees.

5. The next division is one of straight or nearly straight axes. It extends from the southern counties of Pennsylvania, to the southern side of Augusta, Pendleton, and Randolph counties, in Virginia, with a strike of the rocks about north thirty east, or south thirty west. This we call the Potomac Division,

6. The portion of the chain next succeeding has a decided sweepj concave towards the northwest. It extends from the southern limit of the previous one to the New river, and being extensively watered by the tributaries of the James river, may be designated as the Jamss River Division, The belt here referred to differs from the three last, in possessing a less symmetrical topography, and a less regular strike in its strata. Its axes are also shorter and less perfectly parallel, and the whole tract is considerably narrower, the width, from the Blue Ridge northwestward, across which the undulations of the strata extend, not exceeding sixty miles.

7. The division next in order, which is one of straight axes, com- mences northeast of the New river, in Virginia, and extends nearly to the month of the Holston, in Tennessee. Being watered for a great distance longitudinally, by the latter stream, it may be appro- priately named the Holston Division. Both in the style of the topog- raphy, and the phenomena connected with the dipping of the strata, this is one of tlie most remarkable parts of the chain. The direction of its axes and faults is about north sixty-seven east, and south sixty- seven west. Its length exceeds two hundred miles, but its breadth is somewhat inferior to that of any of the previous divisions, not amounting to more than fitlby-five miles from the Blue Ridge to the most northwestern axis.

8. At the southern termination of the belt above described, near the mouth of the Holston, commences the next division of the chain. This has a curving outline, concave towards the northwest, the di- rection of the axes and the strike of all the strata, gradually changing from south sixty-seven west, to south thirty-five west, making a de- flection of thirty-two degrees. Traversing the central parts of east- ern Tennessee, and including in it the well known town of Knoxville,

it may be entitled the Knoxtille Dituion, In this, as in the division last mentioned, the whole distarbed space is comparatively narrow. 9. The last or ninth division of the chain extends from the south- em termination of the Knoxville section, near the moutli of the Clinch river, to the neighborhood of Tuscaloosa, in the centre of Alabama. This we propose to call the Alabama Diviiion. Unlike the district jnst preceding, it exhibits almost perfect Btraihtness in its axes; the strike, which is about south thirty *five west, continuing un- changed until the strata disappear beneath the horizontal formations of the cretaceous and tertiary systems of middle Alabama.

Phedomtnancb op Southeastern Dips.

While tlie general direction of the Appalachian chain is north- east and southwest, there is a remarkable predominance of south- eastern dips throughout its entire length from Canada to Alabama. This is particularly the case along the southeastern or most disturbed side of the belt, where it is strikingly exhibited in the great valley, and in the extensive mountain ridges that bound it on the southeast. But as we proceed towards the northwest, or from the region of greatest disturbance, the opposite, or northwest dips, which previ- ously were of rare occurrence, and always very steep, become pro- gressively more numerous, and, as a general rule, more gentle.

Of the prevalence of this interesting general law throughout all the part of the chain extending from western Massachusetts into eastern Tennessee, we have convinced ourselves by a personal ex- amination of the entire tract, during the last six years, and have partially announced it in various passages of our Reports on the Geology of New Jersey, Pennsylvania, and Virginia. We learn from Dr. Charles T. Jackson, and other sources, that the prevailing south- eastern dip extends to western Vermont, and the valley of Lake Champlain.

Upon the correctiinterpretation of this singular feature depends, we conceive, the clear elucidation of whatever relates to the dynam- ical actions which the region has experienced, to the stratagraphical arrangement of the rocks, and as immediately connected with this, to the distribution of their organic remains. The object of the pres- ent paper is, to exhibit those general laws of structure, of which the feature in question is but a simple and immediate consequence, and to develope what we have for several years past regarded as the true theory of the flexure and elevation of the Appalachian rocks.

History of the PREViors Explanations of the General South- easterly Dip in the Great Appalachian Valley.

The first published attempt at explaining the seeming anomaly of a general southeasterly dip across tlie great valley, was made by Prof. Hitchcock, in the first edition of his Report of the Geology of Massachusetts, in 1883. This explanation, which was confined to the phenomena of western Massachasetta, supposes a series of ua-

oonforraable deposits all dipping to the east, at different angles; but Prof. Hitchcock does not suggest the idea of either an inversion or a folding of the rocks.

At an early period in the geological surveys of New Jersey, Penn- sylvania, and Virginia, we were struck with the great prevalence of the southeasterly dip of the strata throughout the portions of the Appalachian chain traversing those states, and recognized its de- pendence on the oblique or inverted folding of the strata. This will appear from the descriptions we have given of the phenomena, in our Annual Reports for 1837 to 1889. The important general law of a greater steepness of the dip on the northwestern than the south- eastern sides of the anticlinal axes, became known to us at the same stage of our inquiries, and was first announced in the Final Report on the Geology of New Jersey, written in 1839, and pub- lished early in the spring of 1840.

Our solution of this question of the southeasterly dips, which we have long supposed to constitute the only key to the structure of our great mountain chain, was communicated in conversation to Professors Hitchcock and Emmons, at the first Annual Meeting of the Association of American Geologists, in the spring of 1840.

The next notice in the order of time of this structure is, that given by Prof. Hitchcock in his Elementary Geology, published in August, 1840. In this work. Prof. 11. refers to our published ob- servations respecting the extensive inversion of the strata in Penn- sylvania and Virginia, and proposes to explain the prevailing south- easterly dip in western Massachusetts, and the Hudson river dis- trict, by the hypothesis of a simple but vast inversion of all the rocks extending entirely across the region in question. This explanation, accompanied by a short section through the Hoosic and Taconic mountains, is given as an instance of intenion and not of the fold' ing of strata, the latter subject being discussed separately on an- other page.

At a meeting of the American Philosophical Society, on the first of January 1841, one of us communicated the results of some obser- vations upon the geological structure of Berksliire, Mass., and the neighboring parts of New York, which we had made during the month of August previous, and gave an outline orally of our theory, explanatory of the phenomena. Afler adverting to the statements of previous writers, that all the strata between the Hoosic mountain and the Hudson river, lie in an inverted order, drawings were ex- hibited, proving the existence of numerous closely-foldeii anticlinal and synclinal axes; and the inference was drawn, that the inverted dip of the rocks is the result of a folding of the beds at short inter- vals, and not of one general turning over of the whole series, as sug- gested by Prof. Hitchcock. Subterranean igneous action was re- ferred to as having caused this compression and folding of the rocks, and its energy was shown to have been greatest along the Berkshire Talley, and tFie ridges lying to the east. To the same agency was attributed the crystalline condition of the Berkshire marble, and of the aaeociated schists and semi-vitrified quartz rock, the first being

regarded as merely tbe blue limestone of the Hadson vallej, exten- sively altered, and tbe last a higbly altered form of the white sand- stone at the base of the Appalachian formations.*

In the following April, Prof. Hitchcock, in his yery able address to the Geological Association, speaking of the remarkable apparent inversion of the dip, along the western side of New England, and through the Appalachian chain, no longer ascribes the phenomena simply to a toss over of the strata, but to a succession of folded axes, causing a high or more frequently an inverted dip on the west- ern side. In another part he states, that although he does not fully adopt, he cannot but look with a favorable bias upon this solu- tion of the problem.' In explanation of the manner in which the strata acquired this folded structure, he supposes that while yet in a plastic state, and but slightly elevated, they were acted upon by a force exerted in opposite directions, from near the Hudson and Con- necticut rivers; and observes, that this force, Mf powerful enough, might cause them to be folded up into several ridges, and if more powerful along the western than the eastern side, they might fall over so as to take an inverted dip without producing any remark- able dislocation."

In the second edition of his Elementary Geology, published in August, 1641, Prof. Hitchcock, in discussing the phenomena, refers again to the theory of two forces acting in opposite directions at the two extremities of the strata, and suggests in addition the elevating action of gaseous, or melted matter beneath, omitting, however, to account for the general southeasterly direction of the dip.

As the priority of our views in respect to the fact of an inverted and folded structure throughout the chain from Virginia to western Massachusetts, is, we think, clearly established, by our several publi- cations above cited, we can only ascribe the omission on the part of our esteemed friend Prof. Hitchcock, distinctly to recognize it, to the insulated manner in which our descriptions and general views have appeared in our Annual Reports and other occasional publications.

Of the Flexures of the Strata, and tite Law of theib Gra- dation, FROM Southeast to Northwest.

The above described phenomena of the dips in the Appalachian range may, we think, be readily accounted for by the peculiar char- acter of the flexures of the strata. These flexures, unlike the sym- metrical curvature usually assigned to anticlinal and synclinal axes, present, in almost every instance, a steeper or more rapid arching on the northwest than southeatt side of every convex bend ; and as a direct consequence, a steeper incurvation on the southeast than the northwest side of every concave turn ; so that, when viewed together, a series of these flexures has the form of an obliquely un- dulated line, in which the apex of each upper curve lies in advance of the centre of the arch. On the southeastern side of the chain, where the curvature is most sudden, and the flexures are most closely

See Proceedings of American Philosophical Society for Jan. 181L

crowded, they present a snccession of alternately convex and con- cave folds, in each of which the lines of greatest dip on the opposite sides of the axes, approach to parallelism, and have a nearly uniform inclination of from forty -five to sixty degrees towards the southeast. This may he ex[)res8ed, in other words, as a doubling under or inter- 9ion of the northwestern half of each anticlinal flexure. Crossing the mountain chain from any point towards the northwest, the form of the flexures changes, the close inclined plication of the rocks pro- ducing their uniformly southeastern dip gradually lessens, the folds open out, and the northwestern side of each convex flexure, instead of heing ahruptly douhied under and inverted hecomes either ver- tical or dips steeply to the northwest. Advancing still further in the same direction into the region occupied hy the higher forma- tions of the Appalachian series, the arcnes and troughs grow suc- cessively rounder and gentler, and the dips on the op(K>8lte sides of each anticlinal axis gradually diminish and approach more and more to equality, until, in the great coal-field west of the Allegheny mountain, they finally flatten down to an almost ahsolnte horizon- tality of the strata, at a distance of ahout one hundred and fifty miles from the chain of the Blue Ridge or South mountsin.

These general features in the physical structure of the Appala- chian region, will he hest understood hy consulting the Ideal sectiany Plate No. Ill, intended to emhrace the prevailing character of the different portions of the chain from the Blue ridge to the western coal-field. Along with this diagram, which embodies the general results of our observations, will he found several actual seetums comprising the principal details of structure and topography ob- served in different parts of the chain, from New Jersey to eastern Tennessee. These cross the belt at nearly equal intervals, and have been selected from a number, all of which equally exhibit the general conditions of structure above described.

To assist in conveying clear conceptions of the diversified and sometimes complicated modes of structure, occasioned by the flex- ures and foldings of the strata, we deem it important to introduce here two or three new descriptive terms, which seem called for by the necessity of possessing a phraseology adapted to the relation- ships of the strata about to be detailed. Using the terms anticlinal and synclinal in their commonly accepted sense, we propose to apply the phrases anticlinal or synclinal mountain or range to designate ridges formed respectively by a convex and concave flexure of the atrata. Every flexure, of such degree as to fall short of producing an inversion of the rocks on the northwestern side of the anticlinal, and the southeastern side of the synclinal bends, we shall call a nor- mal Jlexure; and the dips corresponding to such flexures, as exhib- ited in transverse sections, we shall denominate normal dips. While the phrases, anticlinal dip and synclinal dip snfliciently express the directions of the beds, due to the concave and convex flexures, we propose the term monoclinal, to signify a sameness in the direction of the dip, and shall term a mountain or a valley, in which such sameness prevails a monoclinal mountain, or monoclinal valley. As

briefly expressive of the whole concave and convex flexure, we propose to nse the terras arch and trough.

Conceiving a plane to be extended through the apex or most in- curved part of each of the concentric flexures in an anticlinal or synclinal bend, so as to occupy a medial position between the two branches of the curve, we propose to call this plane the aavt-plans. "Where the flexure is perfectly symmetrical on both sides of the plane, and the dip on the pne side, therefore equal to that on the other, it is evidit, that the axis plane will have a vertical position. In the Appalachian region, however, and, as we believe, in nearly all other disturbed chains, where the phenomena of flexure are ex- hibited on a scale of much extent, these planes are inclined to the perpendicular in a greater or leas degree, according to the energy of the inflecting force. In the region before us, the dip of the imagi- nary plane is almost invariably to the southeast, tlie amount of the deviation from the vertical altitude diminishing progressively, as we cross the chain towards the northwest. A corresponding law of the axis-planes will, we believe, be found to obtain, in all extensive groups of axes, the general expression of their relation being, that the aip of the axis-planes is always towards the region of maximum disturbance. From the position thus possessed, by the axis-plane, it will readily appear, that its intersection with a horizontal line connecting the southeast and northwest branches of an anticlinal flexure, will lie nearer to the northwestern branch, and that the re- verse will be the case in a synclinal bend. For these relations, see Diagrams, Plate No. III.

Ohabacter of the Flexures in each of the Nine Divisions of

THE Appalachian Chain.

While the flexures of the strata of the Appalachian chain every- where conform to the general type above described, they display in each of its great subdivisions, some one or more prevailing char- acters, marking, as we think, the degree of energy, and the direo- tions of the disturbing forces. Of these, as exhibited in the several divisions formerly specified, the following is a brief account.

1. Hudson River Division. In this belt, the flexures are for the most part, of the closely folded tjrpe, and the dip is almost invari- ably towards the southeast, the compressed and oblique plication of fehe beds extending equally to the hypogene, or primary rocks, of the mountains bounding the valley on the east, and to the lower forma- tions of the Appalachian system, which occupy the valley itself. Northwestward of the valley, this folded condition of the rocks gives place, as in the vicinity of the Catskill mountain to flexures of tiie normal form, which, as we advance, become comparatively ob- tuse.

2. Delaware Division. In this curving district, the formations of the valley, though still often inverted, are not always so, the flex- ures being less abrupt, and sometimes of the steep normal type. Thus, in New Jersey, in the tract chiefly occupied by the lower Ap-

palachian limestone, the troughs become somewhat open, and admit long, narrow, synclinal belts of the next superior division, the great slate mass of the Hudson river. As we cross this division north- westward, beyond the valley, the flexures soon grow very gentle, and as a consequence, the same rocks spread themselves out over very wide tracts, imparting to both the geology and topography a comparatively monotonous character. In all these conditions of flexure in this division, we detect the proofs of a less energetic up- lifting and bending force, when compared with that which operated on the contiguous straight belts, situated to the north and south, where the close and oblique plications fill the valley, and where the steep normal flexnres range further across the chain.

8. Susquehanna Division. Here the obliquely folded flexure is the prevalent one throughout the great valley, giving a general southeasterly direction to the dip. This inversion extends even to some distance northwest of the valley, so as to reach the first an- thracite basin, in the middle or widest portion of which a southerly dip very generally prevails. The flexures or axes of this division occupy a very broad belt of country, extending from Lancaster county, across to the northern line of Pennsylvania, a space of one hundred and fifty miles.

4, Juniata Division. In this region, the strata are generally in- verted, throughout the whole breadth of the South Mountain and the great valley. The principal anticlinal flexures of the Middle Moun- tain-belt are remarkable for their great height and steepness, and for the frequency with which they bring almost the lowest of the Appalachian formations to the surface. These features, with the unusual breadth of the belt, across which the disturbances of the strata extend, would seem to show, that the forces producing the axes of this region were of unusual energy.

6. Potomac Division, This belt is remarkable for the straight- ness of its principal axes, and for the beautiful manner in which it exhibits the general laws of gradation in the flexnres. Upon its southeastern border in the Blue ridge and great valley adjoining, there exists a general tendency to an oblique folding or inversion of the strata, though this condition is less predominant than in the two before-mentioned straight portions of the chain, namely, the Susque- hanna and Hudson divisions. In other words, the rocks are less completely folded, many perpendicular and some northwestern dips occurring, to form the northwest side of the arches, and as we ad- vance beyond the valley, the normal curvatures become the prevail- ing ones. In accordance with this general condition of things, the great valley contains a long central belt of the middle Appalachian formations, included in a deep trough, a feature that could not exist, if the synclinal foldings were as compressed as in the other more in- verted districts. This less closely folded state of the rocks appears to extend entirely across the whole undulated belt, the breadth of which, from the Blue ridge to the valley of the Monongahela, is about one hundred and ten miles. Such a feature seems to imply a less energetic disturbing force in this belt than in the district of

carving axes ajoiDing it on the north, where the rocks in the vaJ- ley are much inverted ; and this inference is supported hy the fact of the very rare appearance, at the surface, of those lower rocks, the older Appalachian limestone, for example, which occupy anticli- nal tracts in the curving belt, and form a conspicuous feature of it.

6. Jame$ River Ditision. This district, sharing with the rest all their essential structural features, and displaying, as formerly men- tioned, especially in its valley portion, much irregularity in the strike of its strata, and the direction of its generally short axes, is remarkable for a confused blending of the various kinds of flexure, even within a narrow breadth, and for the passage, more frequently than in the previous division, of the folded and inverted flexures into faolts. The great valley is here occupied, in part, by the ex- tensive synclinal range of the Short Tlill, and the wide, irregular trough, including the Catawba and Fort Lewis mountains, as well as by other minor ridges of the superior rocks, and is marked by the occurrence of a long line of fault, accompanied by inversion, along the southeast side of the Fort Lewis mountain, and by the prolongation, in a variety of curious phases, of the great fault which extends along the southeastern base of the Little North or Brushy mounUun, hereafter to be more particularly noticed.

7. Hohtan I/ivision. In tliis region, the folded structure, at- taining its maximum limits, assumes the new condition, (evinced, in a few cases, in the preceding district,) wherein the inverted flexures become a series of dislocations, surpassing, for their length, Btraightness, and parallelism, any other group of faults recorded. By far the greater part of the strata dip in one direction, or to the Bouth-soatheast, the downthrow at the faults being invariably on their northwest side. In crossing this region to the north-north- west, after passing for some distance to older and older formations as we approach a line of elevation, instead of meeting with their counterparts, in an anticlinal arrangement, we step at once from some of the oldest of the Appalachian formations, to beds as recent as the European carboniferous . limestone, and thus behold in near contact, on opposite sides of the closed gulf, strata, which origi- nally occupied positions in the vertical column, eight thousand feet apart. This abrupt transition may be noticed, many times in suc- cession, in the first thirty miles, going northwestward from the base of the Blue ridge.

8. Knoxville Di/cisUm, As in the instance of the district last de- Bcribed, the whole disturbed space is comparatively narrow. Here, too, in consequence of the numerous inverted flexures and parallel lines of dislocation, the strata are extensively inverted, having, therefore, very generally, a dip to the southeast, and displaying the normal form of flexure but rarely, until we reach the northwestern Bide of the district. Of this universal prevalence of southeasterly dip, mention is made by Prof. Troost, in his Annual Reports on the Geologicfld Survey of Tennessee, for the years 1839 and 1840,' and we can confirm his statements by our own observations made in the northern parts of the district. An interesting feature in this

belt is the analogy which it displays to the other convex or Janiata division, in the regular or aninterrapted carving of the axes aad lines of strike ; and on the other hand, the decided contrast, in this respect, which they both present to the two concave belts, where the axes are shorter and less parallel.

9. AlcUfama Division, This disturbed tract, progreseively di- minishiog in breadth, from its commencement in Tennessee to its termination in Alabama, displays the usual inversion of the lower rocks, and the other signs of the presence of oblique fiexures, and of that species of dislocation, which results from them, and would seem, from the best information we can collect, to preserve these features of structure without abatement to its extreme southwest- ern end, where it is finally overspread by the newer secondary and tertiary strata.

Thus, every section of the Appalachian chain, whatever its di- rection or curvature, offers the same remarkable and beautiful fea- tures and gradations in its axes, implying that the cause of these phe- nomena was some grand and simple energy, coextensive with the whole margin of the Appalachian sea, from Canada to Alabama.

Exemplification of the Several Modes of Stbuotttbk.

1st. Normal Flexures, Ilaving presented a general outline of the different divisions of the chain, we shall next enter into a description of the several varieties of structure, which distinguish the different parts of it. Flexures of the normal character, constitute, as we have seen, tlie predominant curvatures of the strata, through- out almost the entire length of this mountain zone, the obliquely folded, or inverted axes, being principally limited to a belt of variable width, along the southeastern side. Of the numerous parallel anti- clinal and synclinal ranges, which strikingly exhibit this normal configuration, wo shall cite a few examples from Pennsylvania and Virginia, and refer to the engraved Sections accompanying this paper, for details of the dip in each respective portion of the chain. In the Knobly mountain, the most westerly of the great anticlinal flexures, situated to the southeast of the coal region, the normal character is maintained with great uniformity, throughout a distance of upwards of fifty miles. It commences with the first appearance of the axis, in the immediate vicinity of Cumberland, and continues, as the mountain augments in breadth and height, in its extension to the southwest. Still further in that direction, beyond the intersection of the axis with the North Fork of the Potomac river, in Pendleton county, Virginia, the dips on the northwestern side of the arch become either perpen- dicular, or slightly inverted ; and this attitude they retain for a further distance of about forty miles. Traced from its first appearance, a little southeast of Cumberland, to its termination in the anticlinal valley of Crab Bottom, this axis offers a beautiful illustration of the prevailing regular gradation in the amount of inflection which the strata have undergone, in different portions of the line, as dependent on the varying intensity of the elevating and bending force. At first,

tbe lowest rooks, which the axis exposes, are the red and calcareous shales (For. Y,) or Clinton gronp. Here the ilexnre, though more abrupt on the northwest than on the opposite side, does not exceed a moderately steep normal carvatare. Further to the southwest, where the next inferior formation (For. IV, Shawungunk grit) emerges to the surface, and expands, as we advance, giving an impos- ing breadth and elevation to the ridge, we find the northwestern part of the arch so increased in steepness, that its dips are nearly vertical. The axis, becoming still more developed as we proceed, the next inferior formation (For. Ill, Hudson slates) now makes its appearance, and rapidly expands into an anticlinal valley, which sepa- rates the broad and lotty mountain range into two distinct ridges. The strata of the northwestern of these crests have a vertical, and even, sometimes, an inverted dip. Btili further, in the same line, a yet lower formation rises, the great lower Appalachian limestone (For. H), and occupies a large portion of the breadth of this anticlioal valley. The dip of the rocks in the northwestern ridge now be- comes, as might be anticipated, very frequently inverted. Passing this culminating portion of the axis, its farther prolongation to the southwest is marked by the foregoing phenomena, in a converse order, until finally, near the head-waters of Back Creek, the divided strata of the higher groups once more unite, to form a gentle normal jBexure, in the inconspicuous ridge at the southwestern termination of the axis.

In the Bull Pmture mountain, which traverses Pendleton and a portion of Bath counties, in a line southeast of the range above de- scribed, we have an example of the retention of the normal struc- ture throughout the entire length of the axis, embracing a distance of more than fifty miles. Here, also, we witness the grual steep- ening of the flexure, as lower and lower groups are elevated to the surface, although the whole amount of the eievatory movement, having, in this case, been less than in>that of the Enobly axis, it has nowhere produced an actual inversion of the dip.

The interesting relation here disclosed between the steepness of the flexure and the amount of actual rise of the rocks, at different pouits in the axis, extends to all the shorter as well as the most pro- longed of these lines, and applies to every part of the AppaJachian chain, constituting a law of structure, connected intimately with the theory of the nature of the folding movement.

Besides tlie above cases, we may cite, for Pennsylvania, the great axis of Wills*s Creek mountain, that of the Black Log anticlinal val- ley, and the still more prolonged one of the Eishicoquillas valley, and Jacks mountain, in all three of which the norroiu type is pre- served, while the relation between the degree of developement of the axis and the steepness of the northwestern dips, as already announced, is uniformly displayed.

2nd. Inr>erUd Flexures, As indicated in the general or ideal Section of the chain, the flexures, accompanied by an inversion of the strata on the northwestern side, are of most frequent occur- rence along tbe southeastern border of the Appalachian chain. In

some districts, however, these foldings extend, for a considerablo distance across towards the middle of the belt, a fact well exempli- fied in the general southeasterly dip of the Pottsville coal-field. The passage from the normal to the closely folded inverted curva- ture, as the developement of the axis increases, is a phenomenon well observed in a number of the principal anticlinal ranges in Pennsyl- vania and Virginia, among which may be instanced the Bald Eagle axis, in the former state, and the Jacksons mountain and the Wolf creek axes, in the latter.

The Bald Eagle axis, commencing some miles south of Hollidays- burg, and ranging west of the centre of Sinking and Nittany valleys, and through the middle of Nippenose valley, terminates south of the Allegheny mountain, a number of miles northeast of Pennsboro*. It thus embraces, in its long and gentle sweep, a distance of about one hundred and twenty miles. For many miles of its length, at each extremity, where it lifts only the middle Appalachian rocks, it displays simply a gentle normal flexure ; but nearer the middle of the line, where it elevates lower and lower formations, and finally brings to the surface the great Appalachian limestone, the arch gradually steepens, until it embraces a vertical, and occasionally an inverted dip, along the Bald Eagle mountain, from the Little Juniata to BcUefonte.

The Jackson mountain axis commences near the northwestern flank of the Fork mountain, in Pendleton county, Virginia, and con- tinues in a nearly straight direction in Jacksons mountain, and the anticlinal valley of the Warm and Hot Springs, as far as Jacksons river in the neighborhood of Covington. This comprises a length of about seventy miles. Traced from its northeastern extremity to within a few miles of the first exposure of the lower Appalachian limestone, the mountain continues single, and displays a normal, regularly increasing arch, with a steepening northwest dip. But further towards the southwest, from the commencement of the anti- clinal valley, in which the limestone rises, to the lower end of the Falling Sprilig valley, the mountain divides itself into two ridges, that on the northwest exhibiting both perpendicular and inverted dips. Beyond the Falling Spring, the valley rapidly closes up again by the subsidence of the axis, and at Jackson's river nothing re- mains of this remarkable range but a low ridge, composed of the higher rocks, arching over in a moderately obtuse normal flexure.

The Wolf creek axis, in Virginia, rises near the head of Stony creek, a little southeast of Peters's mountain, and ranges along the southeast side of Peters's and the northwest side of Wolf creek mountain, and Rich mountain, for a distance of between seventy and eighty miles. Throughout nearly the whole of its length, this axis lies in the lower Appalachian limestone, in which there is an inversion of the dip on tne northwest side of the axis plane, that sometimes passes into a fault. This inversion is strikingly displayed along the southeastern base and slope of the synclinal mountain called Buck-horn ridge, adjoining the axis on the northwest, where the strata of this side of the mountain are folded over so as to lie

in almost parallel posture with the corresponding rocks on the op- posite or northwestern side of the trough.

3rd. Flexures broken or pumng into faults. A feature of fre- quent occurrence in certain portions of the Appalachian helt, is the passage of an inverted or folded flexure into a fault. These dislo- cations, preserving the general direction of the anticlinal axes, out of which they grow, are usually prolonged to a great distance, hav- ing, in some instances, — for example, in southwestern Virginia, — a length of ahout one hundred miles. These lines of fault occur in all cases along the northwestern side of the anticlinal, or the south- eastern side of the synclinal axis and never in the opposite situa- tion. This curious and instructive fact is hest seen hy tracing, longi- tudinally, some of the principal anticlinal axes of Pennsylvania and Virginia. From a rapidly steepening northwestern dip, the north- western branch of the arch pusses through the vertical position, into an inverted or southeastern dip ; and at this stage of the fold- ing, the fault generally commences. It begins with the disappear- ance of one of the groups of softer strata, lying immediately to the northwest of the more massive beds, which form the northwestern summit of the anticlinal belt. The dibslocation increases as we fol- low it longitudinally, group after gronp of these overlying rocks disappearing from the surface, until, in many of the more prolonged faults, the lower limestone is brought, for a great distance, with a moderate southeasterly dip, directly upon the carboniferous forma- tions. In these stupendous fractures, of which several instances occur in southwestern Virginia, the carboniferous limestone being brought into close proximity to the great lower Appalachian lime- stone, a portion of which, even, is occnsionally buried, the thickness of the strata ingulfed cannot be less than seven thousand or eight thousand feet.

The position of the strata along some of these extraordinary dis- locations may be seen in the Sections 0. D. E. (Plate No. V) ac- companying this paper. Sections D. and E. represent (at a) the conditions prevailing in the prolonged fault on the northwest side of the axis of the Sweet Springs Valley. This axis in its normal state, brings up the great lower Appalachian limestone, flanked on the northwest by the overlying slate and sandstone, which, together with the northwestern half of the limestone, have a steep northwest- em dip. More towards the southwest this dip augments; the strata on the northwest side of the axis soon become vertical, and thence quickly pass into the inverted position. At this point, the fault begins, being marked, at flrst by the disappearance of a portion of the slates (For. Ill) and variegated shales (For. V), adjoining the thick-bedded sandstone (For. IV), which forms the framework of the ridge, that bounds the anticlinal valley on the northwest. It presents, as it ex- tends sonthwestward, a continually augmenting hiatus in the geo- logical series, ingulfing in succession nearly all the strata between the limestone of the axis, and the carboniferous limestone, and exhibit- ing an inversion of the latter, for some distance across to the north* west of the line of fault. The inversion of the strata near the dislo-

cation on its northwest side, giTint them a southeasterly dip, be- comes less as we recede from the faiilt. By a gradual transition the dips become perpendicular, then steeply inclined to the northwest, and eventually, at no great distance, very gently so ; after which a few broad and feeble undulations succeed, as we pass into the coal region. Tracing this line of fault, in a south westeny direction, for a distance of upwards of one hundred miles, we encounter, at various points, portions of the ingulfed strata, which occasionally reappear to form isolated knobs or short ridges, inclosed betweoi the two great limestone formations (For. II and For. XI), the crushed edges of which, however, are usually not thus separated. The detached masses, so curiously wedged into the chasm of the fault, consist of small remnants of the thick slate group, which underlies, at some interval the carboniferous limestone, and of the hard white sand- stone (For. IV, Shawungunk grit), which constitutes, as it were, the bony skeleton of our principal Appalachian ridges.

Sections 0, D, and £, show (at c) the conditions usually prevail- ing in a very remarkable line of fault, which extends, with but few interruptions, along the western margin of the Great Valley of Vir- ginia, throughout the chief part of its length. The ridge, which bounds this valley on the northwest, and which, as we pursue it Bouthwestward, assumes successively the names of Little North mountain. North mountain, and Brushy ridge, marks the position of this extraordinary dislocation. With the exception of several inter- vening spaces, some distance south of the James river, in which the nonnal, or northwestern dip of the rocks in this ridge, is in the main retained, its strata assume an inverted attitude, the great lower Appalachian limestone of the valley, lying on the slates of the next superior group, and these, in turn, resting with a southeast dip on the white sandstone, while the adjoining formations of a still higher position in the series, are either partially or entirely swallowed in the fissure. The sandstone itself, which, throughout a part of the Suite, gives prominence to the ridge, and the slates intervening be- tween it and the limestone, are both more or less ingulfed, and in some parts of the line, the whole mass of the mountain has disap- peared; so that the observer may cross, by a single stride from the very ancient limestone of the valley, to beds but little lower in the aeries than the carboniferous limestone. Still further along the line, the formations thus lost are seen partially rising again into view, the white sandstone (For. IV) first showing itself in insulated knobs or patches, and afterwards in a continuous, low, and irregular ridge, in which some of the other missing groups also reappear. Between a point a few miles south of the intersection of the James river with this ridge, and the neighborhood of Abingdon, near the Tennessee line, this fault assumes a more uniform, though, perhapa, a still more extraordinary character. At the passage of the river, the massive range of the North mountain presents no other indications of this line of fault than a partial inversion of the thick beds of sandstone, of which it principally consists, and an entire overthrow and partial bnrial of tiie slates which flank it on the southeast. But a few

miles farther towards tlie southwest, the whole of this enormous monntain mass sinks from view, excepting an isolated knob here or there, of the harder rocks, which, for a short distance serve to mark the irregular progress of the fault. At length the dislocation attains what may be called its maximum intensity; the slate, and not un- frequently, the limestone of the valley, resting in an inverted atti tudp, with a gentle southeast dip, directly upon the southeasterly dipping grits and shales of the formation next beneath the carbonif- erous limestone, here constituting the southeastern slope of the Brushy mountain. The seam of semi-bituminous coal, generally embraced between these strata, is, in virtue of the dislocation, made to assume the anomalous condition of passing under the valley lime- stone at a distance of only a few hundred feet, dipping in the same direction with that rock.

Preserving these features, with but little variation, throughout its whole course to the southwest, this extraordinary fault extends, in an almost perfectly straight line, along the southeastern slope of the Brushy mountain, from near the head of -the Catawba creek, to the vicinity of Smyth court-house, a distance of more than eighty miles. At no point, in this line, are the rocks which originally formed the counterpart to the strata of the Brushy mountain, and which are, in fact, represented by those of the Little North moun- tain, in the northern part of the line, even partially restored to the surface; so that this stupendous dislocation is to be viewed as hav- ing actually swallowed up the rocks of the southeastern half of a large synclinal basin, of which the Brushy mountain remains as the other half.

4th, Of the distribution of the aatei in groups. Wherever, in the Appalachian chain, we become minutely familiar with the undula- tions of the strata, we find it impossible to resist the conclusion that the axes arrange themselves in natural groups, the individual flex- ures showing a close agreement in their length, mutual distance, straightness, or curvature, and in the extent and style of the arch- ing. In those districts which are crowded with normal axes, such as the Susquehanna and Juniata divisions, many such groups attract our notice. Each of these assemblages of axes being generally dis- tinguished by some special character, we are inclined to regard the comparison and analysis of their several features as of the very highest importance, in those investigations of geological dynamics into which the whole subject of flexures must evidently lead us. The limits of the present memoir preclude a detailed description of each group of axes, contained even in the States of Virginia, Penn- sylvania, and New Jersey, where we have principally explored them, and altogether forbid auy attempt to apply our theory of flexures to an explanation of the local features, distinctive of each group. We shall, therefore, content ourselves with describing two or three of these collections of axes, more for the purpose of prov- ing our present general statement, that the axes do thus assort themselves, than with a view to discuss the secondary causes oon nected with their peculiarities.

The great divisions, into which the entire chain ratorally divides itself, are alone abundantly significant of this essential tendency of the axes to form groups. For, upon a general view of the whole chain, each of the nine extensive belts, into which we have divided it, becomes one comprehensive group, in which all the axes display certain common characteristics of straightneas or curvature, as the case may be. Lest, however, it should be supposed that tliis group- ing of the flexures is only to be recognized when we embrace very extensive subdivisions of the chain, we shall refer to smaller tracts, and show, that axes of all dimensions thus associate themselves. An excellent instance of a group is to be seen in a district composed of the northern half of MifQin, and the southeastern half of Centre counties, in Pennsylvania. The axes which belong to the general convex system of the Juniata accord remarkably, in all their essen- tial features. They are either of the normal type, with steep north- western dips, or they have the northwestern part of the arch slightly inverted. They are almost exactly parallel, curving a little in obedience to the general sweep of the chain, while they are sin- gularly equidistant from each other. As each flexure possesses nearly the same transverse form and dimensions, they bestow a strikingly regular and symmetrical topography on the whole region, the grt'at lower Appalachian limestone and slate groups rising to the surface in a series of long and parallel anticlinal valleys, while the overlying sandstones compose so many intervening, steep, straight and regular synclinal ridges.

Another well characterized belt of flexures fills the Lewistown valley in Pennsylvania; applying this name to the whole of the long, natural valley, which extends from the Susquehanna to the Juniata, southeast of Jacks mountain. In a breadth of about six miles, there are here usually from five to six long, parallel, and gently curving anticlinal axes, all of them of the normal form, re- sembling each other very nearly in the steepness of the dips, or average degree of flexure. The lowest rocks, which they Kit to the surface, are the variegated shales, (For. Y, Clinton group,) and the highest, which their intermediate troughs have retained, are the sandstone (For. YIl,) and the overlying slates of For. VIII.

A third very natural group of flexures is to be noticed in the eastern part of the middle anthracite coal-field of Pennsylvania. The axes in question separate that region into an assemblage of small, parallel coal basins, of which the Beaver Meadow basin is one. Like the previous groups, these axes are characterized by their remarkable parallelism, their similarity in length, their exact equi- distance, and their gentle gradation, approaching to equality in the degree of the flexure.* They all of tliem bring to the surface the conglomerate which next underlies the coal, and the troughs, which they form, contain about the same moderate depth of coal measures,

The authors, in a marginal note, have changed this sentence so as to read : Like the previoufl groups, these axes are characterized by their remarkable paralleUflm, their similarity in length, their gradually inoreoMing distanem and their gentle gradation m degree oi the flexure." — £d.

growing shallower, however, to the northwest. This collection of axes, unlike the two groups before described, belongs to a struight system.

If it were desirable, we might extend the enumeration of the groups of axes to every part of the Appalachian chain, but abun- dant evidence has been furnished, to show that our anticlinal axes are not irregularly distributed, but maintain relations with each other, which require that they should be classified and studied col- lectively. Their ffencric resemblances examined, they will be found to exhibit general laws and analogies, that cannot fail to lead to some highly curious results concerning the forces, which from time to time have thus undukted the earth's crust. That this curious and most instructive department of geological dynamics has es- caped, until lately, the attention of the be$t investigators, we can only attribute to the fact, that in Europe, no belt of axes, equal in extent to the Appalachian system, has come within the notice of geologists. Before a philosophical theory of flexures can be framed, large opportunities must be had for classifying their phenomena, and tracing their laws of gradation.

It is a curious and important fact connected with this group of axes, that in certain cases, chiefly, we believe, in wide and deep troughs, the included smaller axes or wrinkles, though parallel to each otfier, are not parallel to the general synclinal axis of the basin, in which they occur. This feature is obvious in all the deep anthra- cite coal-basins of Pennsylvania, especially near their terminations. These lesser, subordinate axes, generally have a strike parallel to that of one of the great flexures bounding the basin ; but, on account of the convergence of the sides of the trough, they are necessarily- more or less oblique to the opposite margin. They are, therefore, 80 many long, parallel warpings of the strata, conforming to one boundary, but abutting acutely against the other. Sometimes, in- deed, they cross the basin very gradually, or pass almost longitudi- nally, from one side to the opposite, and die out, as wrinkles on the slopes which bound the basin. That they have originated in an inequality in the energy of the linear forces concerned in bending and elevating the rooks along the principal flexures, and arise there- fore, from an actual warping of the strata, seems altogether proba- ble. If 80, they are secondary consequences of those more general and extended movements, which give existence to the grander flex- ures, in whose folds they lie. To describe all the phenomena relat- ing to these minor assemblages of axes, the full investigation of which, as it concerns the mining operations of our coal-fields, is, perhaps, the most useful practical inquiry that the geologist can un- dertake, would demand a body of minute details, only to be eluci- dated by a general map of the flexures, not yet ready for publication.

5th. ParallelUm of the axea in each group. The parallelism of the several axes or lines of flexure, which compose a group, either extensive or limited, is one of the most remarkable relations. The descnptiona already furnished show, that it prevails in every portion of the chain, whether straight or curved, and extends even to the

members of the smallest gronps. A striking exhibition of this ma- tual parallelism may be noticed among the inverted and normal ilex- nres in the great valley, in that part of the chain which we have called the Potomac division. Some of the larger axes are there prolonged, side by side, for nearly one hundred miles. The same fact may be equally well seen in the great corving axes of the Juniata division, and amongst those most remarkably persistent flexures, which divide the parallel bituminous coal-fields northwest of the Allegheny mountain in Pennsylvania and Virginia. It is yet more strikingly displayed, perhaps, in the long and singularly straight axes and faults of the Holston region, in Virginia and Tennessee, where the lines, both of flexure and of dislocation, maintain almost exactly the same distance from each other for upwards of one hundred and fifty miles. This parallelism, however, is after all but approximate, though, as many of the adjacent axes of a group in a length of say fifty miles, observing a mean distance of not more £han two or three miles, seldom approach or recede more than a fourth of this space, we are justified in seeking for some theory which shall explain so conspicuous a relation.

6th, Of the great length of some of the axee. Perhaps nothing astonishes the geological traveller in the Appalachian chain, so much as the enormous length and persistency of many of the axes. Tracing these lines of flexure longitudinally, they will not unfrequently be found to range for eighty or one hundred miles, with but little de- viation either from perfect straightness, or from a uniform gradual curvature, narallel to the general inflection of the division of the chain, in which they are included. This astonishing regularity and lengtli is, perhaps, best noticed in the axes of the northwestern side of the belt, where they frequently exhibit a steady curvature, for more than one hundred and fifty miles. Whether the southeastern axes are less prolonged, or whether their crowded condition often conceals the continuity of their range, are points we do not at pres- ent undertake to decide. Among the very numerous instances of long and regular axes of the steep normal type, we must specify, in the Susquehanna region, the straight axis of Montours ridge, which extends about eighty miles ; in the Juniata division, the beautifully inflected axis of Jacks mountain, continuous for more than ninety miles ; in the Potomac division, the straight axis of Wills's creek mountain, ninety miles in length, and also that of the Knobly moun- tain, nearly a prolongation of the last, itself a hundred miles long. To these we may add, for the Holston region, the straight axis of Wolf creek, and that of the Clinch mountain, the former of which is about one hundred miles, and the latter more than one hundred and twenty miles in length.

It is probable that numerous axes of the folded or inverted type, quite as extended, exist in the great valley, and the adjacent belt of ridges on the southeast side of the chain, and we have already seen, that where some of the steep normal and inverted flexures pass into dislocations, they have a length even exceeding that of any of the axes above referred to. If we turn to the more depressed

mal axes of the western coal region, wo shall find, that that which lies next northwest of the Potomao hasin, is at least seventy miles long, that of the Negro mountain ninety miles, that of Laurel hill at least ninety miles, and that of Chestnut ridge, or West Laurel hill, more than one hundred miles in length ; and our geological maps will exhibit, in other less well known portions of the same belt, a series of similar obtuse flexures, of even still more extended length.

7ih. Of ike curving ofaxu. It is needless to add much to what has already been said or inferred concerning the horizontal inflec- tion of the axes in some groups, since the changes of strike men- tioned, wliile tracing the great divisions of the chain, involve a parallel bending of all the principal and most influential flexures individnally. Considering the enormous extent of viarpmg which the omst must have undergone, and which we can infer that it did nndergO; from the evidence afforded in the lesser, or secondary flexures, and also from the nature of the faults, the prevailing con- tinuity and graceful, curving outline, witnessed in many of the inflected axes, are truly remarkable. There are cases, as in that of the Jack's mountain flexure, where a continuous axis sweeps for ninety miles, to undergo a change of strike of as much as forty-five degrees, without once taking on a serpentine or contrary incur- vation, or manifesting any considerable inequality in the bending. Instances of such extraordinary length and regularity, are, however, comparatively rare, and are confined chiefly to the divisions of the chain in which the curvature is convex to the northwest. A more common linear form among the longer curving axes, if we except those, — the longest and most regular of all, — which traverse the great northwestern coal region, is one which embraces a partial discontinuity of the line, at one or several points. This discontinu- ity is, in most cases, only partial, being of the nature of a warp, the anticlinal arch embracing, generally on its southeastern slope, another flexure, which either immediately, or at a moderate dis< tance, becomes the principal, and finally the only, anticlinal crest, while the original summit, in its turn, subsides upon the flank of the other. In such cases, where the two closely overlapping flex- ures are included within one general anticlinal arch of about the same average breadth and height as the parts which contain the flexure in its single state, and where the relative depression em- braced by the warp is comparatively trivial, there seems no impro- priety in considering the whole as one great undulation, locally disturbed, from some inequality in the bending or resisting forces. The warp will, in fact, be found, in such cases, to occur commonly near the central portion of the line, where the maximum degree of flexure and elevation, in all strictly continuous axes, has been experienced, and exactly where we would naturally look for the greatest irregularities in the movement of the strata.

When the bearing of the various phenomena of curving axes upon some of the most interesting questions of geological dynamics is contemplated, the importance of a critical investigation of all their modifications of form cannot fail to be recognized. Besides

demanding their proportion of attention, in any theory which attempts to explain the origin of axes, generally, these curving axes of our Appalachian region merit particular examination in another light. They appear to contradict directly the well known hypothe- sis of the distinguished French geologist, M. Elie de Beaumont, which supposes, that a constant relation subsists between the epoch of elevation, and the directions or strikes of the lines of disturb- ance. These curving axes constitute so many intermediate links be- tween the straight divisions of the chain, in which they terminate at their opposite extremities, and they are demonstrably of the same age with the rectilinear flexures, with which they there alternate. But the different sections of the chain, thus referred to one general succession of elevatory movements, differ from each other in their strike as much, in some instances, as forty or forty- five degrees; and, if we include systems of axes not contiguous, but the sameness of whose date is equally demonstrable, — as when we compare the Vermont and the Holston axes, — the difference in direction is even as much as sixty degrees. Here are extensive mountain belts, each upwards of two hundred miles in length, pos- sessing unequivocally the same epoch, differing in the direction of the elevatory movement much more than some of the European systems of widely different geological age. It is obvious, then, that the generalization of M. de* Beaumont, if in accordance at all with nature, is only so as it relates to the general direction of entire mountain systems, and not to the course of special groups of axes, however extended.

Description of a Series of Sections across the Chain.

Section A, (Plate III.) This section extends from the South mountain in Berks county, Pennsylvania, through the anthracite basins, to the Allegheny mountain, in Luzerne county, and exempli- fies the usual features of structure prevailing in the Susquehanna division of the chain, showing the folded and inverted condition of all the rocks in the South mountain and great valley, also the steep- ness of the northwestern sides of the flexures in the rest of the bolt, and the beautiful grouping of the axes, especially in the mid- dle anthracite region, combined with a general progressive reduc- tion in the abrnptness of all the curves and dips. It likewise shows that the hypogene strata of the South mountain are included in the same general system of flexures with the Appalachian strata.

Section B, (Plate IV.) This extends in a west-northwest direc- tion, from the vSouth mountain, in Cumberland county, Pennsylva- nia, through the Broad Top coal-field, to Chestnut ridge, in Indiana county, and offers a striking illustration of the existence of exactly the same structural features, in the curving region of the Juniata, as the other shows in the straight one of the Susquehanna. The folded or inverted axes occupy the belt of the South mountain, and great valley, northwest of which they are succeeded by a broad belt of Bteep normal flexures, several of which lift to the surface nearly

the lowest formations of the system. This section also displays the manner in which the western coal region is divided by the wide and gentle flexures northwest of the Allegheny escarpment.

Section C, (Plate V.) Onr third section crosses the chain in a direction from the Blue ridge, at Ashbys gap, in Virginia, through TVinchester and Romney, to the commencement of the coal rocks, on the Front ridge of the Allegliany mountain. It exhibits normal flexures everywhere but in the Blue ridge and great valley. In the Short hill and Blue ridge, at the southeast end of the section, the sandstones, forming the lowest group of the Appalachian system, are seen in folded anticlinal flexures, which equally affect the older metamorphic rocks, the whole of the northwestern slope of the Blue ridge presenting an inverted or southeastern dip. The general aontheasterly inclination of the axes-planes, or which is the same thing, the greater steepness of the northwestern, compared with the southeastern dips, is very uniformly exhibited in this section. The rocks of the Little North mountain are here shown to be inverted, presenting (at e) one of the phases of the prolonged fault, formerly alluded to.

Section D, (Plate Y.) This section crosses the chain from a point high up on the south fork of the Roanoke river, in Virginia, to the northwest base of the Peterss mountain, near Union. Lying in the James river division of the chain, it exhibits the rather con- fused mixture of normal and inverted flexures and faults, for which that district is remarkable. On the southeast are seen the hold flexures of the strata of the lowest of the Appalachian formations, here of extraordinary thickness, and forming a lofty mountain range, while, immediately behind them, on the southeast, are seen the nu- merous foldings of the ancient metamorphic strata. A fault (at d) at the southeast base of the Fort Lewis mountain, shows Formation II thrown over upon VII I. Some miles towards the northwest (at e) is the great fault of the Little North mountain, presenting Forma- tions II and X, in contact, the former lieing uppermost. Near the northwest termination of the section (at a) is seen the fault on the northwest side of the Sweet spring, or Peters's mountain axis, here showing the contact of For. II with the upper part of For. VIII; the remainder of the latter, together with the other intervening formations, being lost. In this part of the section may be seen the rapid passage of the higher rocks, from inversion to vertical! ty, and thence into a very gently undulating and horizontal position towards the northwest.

Section E, (Plate V.) This section extends from the Poplar Camp mountain, in Virginia, near the mouth of Reed creek, in a north- northwest direction, to the commencement of the coal rocks, imme- diately northwest of AbVs valley. Lying in the Holston division, in the southwestern part of Virginia, it traverses nearly all the great parallel lines of fault, for which that region is so remarkable. At its southeastern extremity we notice the lowest formation of the Appalachian system, bent over into an inverted position, and resting upon the next superior rock, the great lower limestone (For. II.)

Steep norma], and also folded flexures, extend across the valley to the Cove mountain, at the southeast hase of which we meet a line of fault (at d), bringing in contact Fors. II and VIII, with the usual invention of the former. Beyond this, to the northwest, near the southeast base of Brushy ridge (at c), is the great dislocation re- ferred to on previous occasions, and which here brings together Fors. II and a. Still further towards the northwest, in the valley of Walkers creek, on the northwest side of an inverted anticlinal axis of For. II, a similar fault occurs (at 5), with the same hiatus of the intervening formations. Beyoud this, or northwest of tlie Wolf creek axis, we see (at a) an extension of the great fault previously described as running along the northwest side of the Sweet spring, or Peters's mountain axis. A few miles further, we come upon the last, or most northwestern lino belonging to tliis division of the chain.

Inobeasino Imtebval betwbek thb Axes as we advance Nobtr-

westwabd.

It is an interesting general fact, that the space between the axes, or more properly, the amplitude of the undulations, increases as we cross the chain northwestward. This is represented in the ideal section, and is equally apparent in the actual Sections which ac* company it, being strikingly visible in that (Section B) intended to illustrate the structure of the Juniata region. Although most dis- tinctly noticeable in the northwestern side of the belt, tlie gradation prevails equally in the middle and southeastern tracts, but in the latter the numerous minor flexures, with the interference of groups of different dimensions, prevents our at first perceiving the law in all its simplicity and exactness. Towards the southeastern side of the chain, the flexures become so numerous, and are so often folded or inverted, as, in most cases, to render the comparison of their dis* tanoes impracticable. Yet, even in this quarter, the general truth appears, in the diminished space between the foldings, as we cross the Great Valley, southeastward. Taking in the whole breadth of the chain, the prevalence of the rule is obvious, no matter by what Section we cross it.

Theobt of the Flexure and Elevation of the Strata,

FOUNDED on THE PRECEDING PHENOMENA, — COMBINED UNDULA- TOBT AND TANGENTIAL ChABAOTEB OF THE MOVEMENT.

That the movement which produced the permanent flexures was compounded of a wave-like oscillation, and a tangential or horizontal pressure, both propagated northwestward across the disturbed belt, IS plainly indicated by the oblique character of nearly all the anti- clinal and synclinal curves, both those which are closely folded, and those which are obtuse. This oblique inflection of the strata will, we confidently believe, be found to prevail as the regular form of all anticlinal axes in every part of the world. It appears to imply a

powerfol tangential movement, always operating in tbe same di* rection for the same region, during the e[K>ch of disturbance. A merely vertical force, exerted either simnltaneonsly or successively) along a system of parallel lines, could only produce the same num- ber of symmetrical anticlinal arches, while again, a horizontal or tangential pressure, uncombined with an alternate upward and downward motion, at regular intervals, could not possibly result in a system of parallel folds, or axes, or lead to any change in the position of the strata, beyond an imperceptible bulging of tbe whole tract, or else a confused rumpling and dislocation, dependent on local inequalities in the thickness or resistance of the crust, in dif- ferent spots.

That the toavelihis flexures of our Appalachian strata are the re- sult of an actual onward hilhwp movement proceeding from be- neath, and not of a folding due simply to some great horieontal or lateral compression will appear from the following considerations. In the first place, it is absolutely impossible to conceive, that any force, of an intensity however vast, exerted in the direction of a tangent to the earths surface, could by itself shove a thick and im- perfectly flexible crust into a system. of close alternate folds. Be- yond the imperceptible bulging of the whole tract laterally from the Une of application of the force, no flexure could arise, other, perhaps, than some diminutive, but irregular plications, caused by inequalities in the strata or crust, and these, it is needless to remark, would be destitute of any law of parallelism and gradation, such as that which strikmgly characterizes the Appalachian and other regions. No system of narrow waves of the strata, however flat, could originate from the most enormous lateral pressure, if unaccompanied by some vertical oscillation, producing parallel lines of easy flexure. Pre- cisely such an alternate movement would ensue, if a succession of actual waves on the surface of the subterranean fluid rock rolled in a given direction beneath the bending crust.

The inadequacy of the tangential or horizontal force, as a oanse of the Appalachian axes, is still further obvious, when we consider, that no igneous rocks, of any sort, were thrust to the sniface, ex- cept in the belt of country bordering this broad system of flexures on the southeast, and that, therefore, if the axes or foldings were produced solely by lateral pressure, the whole force must have been propagated from the lines, where the wedging in the igneous matter occurred in this southeastern region, to the remotest of the axes, through all the intervening folds. But, consistently with mechanical analogies, such a transmitted force, instead of producing the gentle gradation of flexure, which we behold, would have expended itself in merely compressing or crushing the contiguous tracts across a narrow belt, a little widened by a succession of these tangential actions. The narrow disturbed belt would abound in irregular con- tortions, and beyond it we should suddenly come to the strata in their original horizontality.

That such would really be the effect of the supposed horizontal action, is clearly proved by the singularly undisturbed condition, al-

readj stated, of the strata immediately, and for some distance north* west of all our great lines of dislocation. Along these lines, the nniform inversion, and the crushed and contorted state of the higher rocks immediately northwest of the fracture, indicate plainly an enormous lateral thrust in that direction from the fault. Yet, even where the greatest energy of this force is manifested, the inversion or other disturbance extends only for a few hundred yards north- west of the fissure ; while a little beyond, the horizontal (KMture of the rocks has been even less changed than in parts of the same re- gion, where no fault exists.

Even granting, that such a force, transmitted to a great distance across the chain, were capable of bending the strata of the remoter tracts into gentler undulations, the flexures on their northwestern sides ought to be relatively still steeper than they are, for in that quarter the curves are almost symmetrical. On the other hand, this near approach to a symmetry of curvature in the remoter axes, is an obvious consequence of the greatly reduced force and size of the nearly exhausted waves.

The widening of the interval between the axes, as we go to the northwest, is another general fact, which, while it finds a ready explanation in the hypothesis of a violent undulation of the strata, would seem to be wholly at variance with the operation of a gradual and prolonged pressure, exerted northwestward. Conceiv- mg the various degrees of inflection witnessed in dififerent parts of the chain to have resulted from a long-continned pressure, we should be compelled to admit, that the southeastern side of the tract had had impressed upon it successively all the different gratia- tions of flexure met with throughout the chain, and thus we should have to suppose, that the closely folded, crowded axes of the great valley were slowly developed by a force that in its earlier stuges, produced everywhere only wide and gentle arches. Yet, if such was the case, why do we not recognize a yet more nniform or gradual transition in the dimensions of the axes, than our Sections show. If the steepness of the flexnres measures thus their age, why, it may be asked, are those of the same group so various in this respect, while their intimate relations to each other, in respect to parallelism, gradation of distance and dip, plainly prove tliem to have a contemporaneous origin ? If a long period was consumed in their production, why did there not take place, by virtue of the simultaneous denudation and deposition which must have been in progress, a constantly unconformable superposition of the new de- posits, as the axes slowly rose above the level of the water.

But, while the observed variety in the magnitude and steepness of the flexures thus makes it incumbent on the advocates of such a theory of the gradual formation of axes, to admit, that the folded and closely crowded ones have arisen out of broader and normal curves, the general tenor of their doctrine of progressive and cumu- lative actions, implies, that the short and narrow flexures were pro- duced first, and that some of them were enlarged into the vastly bolder and longer axes, which abound in many ports of the same

r

region. This, however, seems an insnperable difficulty, since, if we suppose the breadth and length thus steadily to increase, a great number of intervening flexures and foldmgs would be neces- sarily obliterated or reversed.

But, quitting the theory of a gradaal horizontal pressure, another hypothesis suggests itself, as likely, in the present stage of geologi- cal speculation to be offered in explanation of the structural laws we have described. It may be urged, that a prolonged upteard ten- sion or pressure exerted along a single line might gradually create a broad and lofty anticlinal flexure, and might, hy a mere shifting of the line, into nositions always parallel to its first one, accomplish in time the elevation of all the axes of our Appalachian groups. Such a supposition would, doubtless, account for the simple features of a symmetrical flexure ; but it would aflTord no clue to an ex- planation of those beautiful relations, which prevail between the form of the flexures and their position in the groups to which they appertain, or to the fact of their assemblage into groups ; and these are among the most interesting general facts, which a theory of flex- ures is called upon to explain. How could a merely vertical force, applied to the interior surface of the crust, either along a narrow line, or over an elongated elliptical, narrow zone, produce that oblique form of the anticlinal arch, which we And to be its normal configuration; or how could it give rise to the regular Jiorizontal bending of the axis-line, as seen in tiie curving districts of the chain. Again, in what way can it ex[)lain the occurrence of the great lines of fault only on the noi'th western side of the axes, or the close oblique foldings, in all the southeastern side of the belt. But, apart from all these objections, on what principle or analogy are we entitled to assuine, that the supposed successive shifting of the upward force would be in parallel lines? Should the elevation theory be modified so as to suppose the upward force to have been exerted simultaneously along the present anticlinal lines, but not in tiie manner of an undulation, the equally fortnidHble diflicnlty arises of accounting for the production of any fiexures ; since, by the close contiguity of the parallel lines of upward pressure, the sole effect would be a nearly unitorm diffused bulging of all that portion of the crust, upnn which the tension was exercised.

Op the Origin op the Supposed Spbterranean Undulations, and OP THE Manner in which the Strata became permanently

Bent And Dislocated.

The parallel flexures of the crust so strikingly exhibited in the Appalachian chain, and recognizable, we believe, in nearly all dis- turived mountainous districts, we conceive to have originated in the following manner : We assume, that in every region, where a sys- tem of flexures prevails, the crust previously rested on a widely ex- tended surface of fluid lava. Let it be supposed, that subterranean causes competent to produce the result, such, for example, as the accumulation of a vast body of elastic vapors and gases, subjected

62S

the disturbed portion of the belt to an excessive npward tension, causing it to give way, at successive times/ in a series of long par- allel rents. By the sudden and explosive escape of the gaseous matter, the prodigious pressure, previously exerted on the surface of the fluid witiiin, being instantly withdrawn, this would rise along the whole line of fissure in the manner of an enormous billow, and suddenly lift it with the overlying flexible crust Gravity, now operating on the disturbed lava mass, would engender a violent un- dulation of its whole contiguous surface, so that wave would suc- ceed wave in regular and parallel order, flattening and expanding as they advanced, and imparting a corresponding billowy motion to the overlying strata. Simultaneously with each epoch of oscillatiou, while the whole crust was thus thrown into parallel flexures, we suppose the undulating tract to have been shoved bodily forward, and secured in its new position by the permanent intrusion, into the rent and dislocated region behind, of the liquid matter iijected by the same forces that gave origin to the waves. This forward thrust, operating upon the flexures formed by the waves, would steepen the advanced side of each wave precisely as the wind, act- ing on the billows of the ocean, forces forward their crests, and imparts a steeper slope to their leeward sides. A repetition of these forces, by augmenting the inclination on the front of every wave, would result, finally, in the folded structure, with inversion, in all the parts of the belt adjacent to the region of principal dis- turbance. Here, an increased aniouut of plication would be caused, not only by the superior violence of the forward horizontal force, but by the production in this district of many lesser groups of waves, interposed between the larger ones, and not endowed with sufficient momentum to reach the remoter sides of the belt. To this interpolation we attribute, in part, the crowded condition of the axes on the side of the undulated district, which borders the region where the rents and dykes occur, and to it we trace the far greater variety which there occurs in the size of the flexures.

In the progress of this bending and folding of the stata, through- out the undulated district, the continual introduction and consolida- tion in the fissured district, of fresh materials from the liquid mass beoeath, rising in intrusive dykes, and filling the wide interstices of the broken strata, would permanently retain the inflected crust in the new attitudes into which it had been forced, and compensate for the reduction of horizontiil breadth arising from the flexures. Permanent axes might even be produced without the fracturing of the crust being in all cases apparent at the surface, since innumer- able fissures, of sufficient size to permit the sudden escape of an enormous quantity of elastic vapor, could temporarily form, and yet close again superficially, and still the strata be braced and retained in their flexured state by the dislodgement of fragments, and the intrusion and congelation of much lava matter in the lower parts of the rents.

This theory agrees strikingly with the singularly undisturbed con- dition of the strata, northwest of our great lines of fault. When

describing, under a preceding head, some of these enormoas dislo* cations, especially those of southwestern Virginia, an account was given of the gradual transition of structure, from the normal to the folded or inverted form, and thence, to a successive ingulfing of cer- tain groups of strata, into a line of fault, presenting sometimes, for the distance of seventy miles, an actual inversion of the lower Ap- palachian limestone or slate, upon either the carboniferous limestone or the next inferior group. The commencement in all cases of these faults, in the steeply folded synclinal part of the flexure, immedi- ately on the northwest of the finally inverted anticlinal curve, would seem to prove conclusively, that the fracture has been due to a pro- found folding in and inversion of the rocks, carried to the extent of producing an actual snapping asunder of the beds where most in- curved, followed by a squeezing downward of the opposite side of the trough, by the horizontal northwestward thrust of the anticlinal portion, causing the lower strata of the latter to lie directly upon geologically higher groups. The enormous mass of rocky material, thns forcibly pressed down and firmly held there, would, we con- ceive, constitute a vast auhterranean harrier or dam, capable of ar- resting, in some degree, the progress of the succeeding waves, and of protecting Uie region for a moderate distance, towards the north- west, or tlie leeward side of the fault, from the undulations to which it would otherwise have been exposed. In confirmation of this view, it may be stated, that in tracing a line of dislocation toward either extremity, while the extent of strata thrnat down, as indicated by the amount of the hiatus at the fault, is inferred to grow progressively less and less, or, what is the same thing, the sup- posed subterranean dam, presumed to diminish in depth, the region behind it, on the northwest, becomes more and more undulated, nntil, when we pass beyond the extremity of the fault, to where the normal form of the flexure is restored, we find the strata to the northwest reared into bold anticlinal and synclinal curves. 8nch is remarkably the. fact with the fault at the northwest base of the Peterss and East river mountain, in Virginia, as well as with that which lies parallel to, and southeast of, the Cumberland mounUun ; and in a word, with all the faults and crushed axes of great length throughout Virginia, Pennsylvania, and Tennessee. Even where two such lines of dislocation occur, parallel to each other, at an interval of not more than eight or ten miles, the cen- tral parts of the intervening tract exhibit unusually little disturb- ance, notwithstanding their proximity to the lines of violent dis- ruption on each side.

The assumed combination of the wave-like oscillation, and hori- zontal or tangential movement, will explain, we believe, all those general structaral phenomena, which we have described as charac- terizing our Appalachian chain in all its length and breadth, and which obviously exist in many other mountain chains possessing numerous axes. It will account for all the varieties of flexure, nor- mal, inverted, or dislocated, which are any where observable in the chain, since a mere diflference in the ratio of the tangential to the

nndulatory moyement, would produce every grade and form of in- flection we baye had to record.

The theory explains, moreover, the remarkable law of diminish- ing steepness in the flexures, as we cross the whole belt northwest- ward from the region of intrusive veins and dykes, which has evi- dently been the quarter of extensive and violent actnal disruptions of the crnst. It moreover affords a reason for the striking parallel- ism which prevails between the axes in every division of the chain, and the veins and dykes in the corresponding tracts to the south- east. In this rent and dislocated zone of country, beginning with the chain of the Blue ridge, the incalculably numerous and greatly extended dykes and veins that everywhere penetrate and fill the altered and hypogene rocks, comprise, we believe, an ample quan- tity of inwedged material, to balance the horizontal contraction of the whole plicated chain.

The mere fact of a regular gradation in the amonnt of fiexnre, is of itself a proof, that the axes thus related had a common source, while the direction of this gradation, clearly establishes, that the southeast was the quarter from whence the movement pro- ceeded.

The views here entertained of the nature of the elevating action, afford a satisfactory cause for the arrangement of the axes in groups, since we have merely to imagine successive sets of pulsations of varying magnitude and momentum, to have followed each other in the same general period of disturbance, nnd we are supplied with a cause sufficient to produce all the diversity which we behold in the distances and directions of the flexures. The almost exact parallel- ism of these in each group, and the general parallelism of all that enter into the same division of the chain, are the necessary results of that wave-like movement in which we conceive the axes to have originated ; and we confess ourselves at a loss to imagine how any other action, but an undulation of the crust, propagated in parallel lines, either straight or curving, could give rise to this extraordin- ary feature in these enormously extended anticlinal and synclinal lines.

The curious facts connected with the curving form of the axes, in certain districts, are likewise well accounted for by the hypothe- sis. Of those divisions where they are eantex to the northttesty and where the curvature is generally so regular, we have merely to sup- pose that the disturbance began with the production of the axes of each adjoining division, that these terminated towards each other in an obtuse angle, but did not meet, and that, in the angle between them, there was afterwards formed another intermediate belt of undulations. The extremities of these last waves, encountering the flexures already formed in the adjoining straight belts, would be obstructed and re- tarded in their progress northwestward ; but the middle portion of each billow, moving in a tract as yet free from permanent axes, would meet with less impediment, and advance with a higher veloci- ty, so as to impart to the whole of each axis a curvilinear form. It appears, moreover, highly probable, that the fractures of the crust

in the dislocated district in the southeast, would themselves be more or less cnrvilinear in the yicinttj of previously formed rents ap- proaching each other at an obtuse angle, and thus a tendency to that shape might be primarily impressed on all tlie undulations taking their origin in a region so circumstanced.

On the other hand, in those sections of the chain where the axes have a concave curvature n&rthwestwardy and where there usually exists less regularity in their sweep than in the convex groups, we may imagine that the lines of elevation of the two a(\jacent straight belts, terminating nearer and nearer to each other, as the axes re- ceded towards the northwest, would soon mutually interfere, and the undulations originating at the southeast, in tlie space opposite the angle, would find their progress northwestward more and more impeded, as they advanced through the narrowing area between the ends of the flexures previously formed. By unequal and multiplied obstructions thus occasioned, the regularity of the axes in the inter- mediate division would "be greatly impaired.

There is a curious arrangement in chellon, which we notice in many of the groups of axes of the Delaware river or New Jersey division, where though individually nearly straight, they change their strike more and more to the north as we advance northeast- ward. This admits of a simple explanation, if we merely suppose a portion of the flexures in the next straight belt on the southwest to have been first produced, and these to have been followed by those on the northeast, which occupy New Jersey and the contiguous dis- tricts of New York, the undulations starting as usual from the south- east. The latter, originating last, with a more northern strike, would converge upon the former as the waves advance north westw, and coming in contact with the eastern extremities of the previous flex- ures, would encounter a retardation at their southwestern ends, while their remote or northeastern extremities would be free to advance with their whole velocity. The natural tendency of this species of resistance, would be to break the retarded wave, and to ve the northeastern portions a more northerly strike. The whole movement may be likened to the march of a platoon of soldiers in what is called a right oblique order, wherein the advanced files slightly wheel upon the left.

The hypothesis we have advanced, seems also to explain the im- portant fact, that the whole undulated surface, estimated by the average change of level of any given stratum traced across the chain, rises in a regularly inclined plane southeastward, or towards the quarter where we find, by other evidence, that the uplifting and un- dulating action was most powerful. This circumstance, of a pro- gressive rise of the whole belt towards the side which anciently lay near the shore of the Appalachian ocean, accords entirely with the belief, that under the now rent and dislocated margin of the chain, there was a vast accumulation of fluid rock, charged with com-

Sressed gaseous matter, which exerted on the crust an enormous isrupting tension.

Ok the Idenutt of the Undulations which fboduokd the Axes, witu the ways-uke Motion of the Eabth in Eabth- quakes.

That the nndiilatory movements which we suppose to have been tlie primary cause of our Appalachian axes, and generally of all other parallel flexures, were strictly analogous to well-known phe- nomena of the present day, is apparent, when we examine the na- ture of that tremendous agitation of the crust, which we call an earthquake. A wave-like undulation of the ground is of such com> mon occurrence during great earthquakes, that we are inclined to consider it their essential condition. On this subject, we possess the concurrent testimony of the best observers and historians of these events, particularly Michell, Dolomieu, Lyell, and Darwin. Michell, writing on the subject of The Cause and Phenomena of Earth- quakes,'' in the Philosophical Transactions for 1760, says, that the motion of the earth is partly tremulous, and partly propagated by waves, which succeed one another at larger and smaller distances, the undulation extending much further than the tremor. At Ja- maica, in 1687-8, a gentleman saw the ground rise, like the sea, in a wave, as the earthquake passed along, and he could distinguish the effects for some miles, by the waving of the tree-tops on the hills. The same was witnessed in New England, November 18th, 1766. The wave-like motion of the great Lisbon earthquake, which happened on the 1st of November, 1756, was perceived by the mo- tion of water, and the hanging branches in churches through all Germany, among the Alps, in* Denmark, Sweden, Norway, and all over the British islands. This tremendous movement even reached the West Indies, a distance from the seat of principal violence, of nearly three thousand miles. A comparison of the times at which the first shock was felt at Lisbon and at other places, shows the un- dulation to have travelled at the rate of more tlian twenty miles per minute,

Dolomieu, in his dissertation on the great Calabrian earthquake, states, according to Mr. Lyell, that 'Hhe surface of the country often heaved liked the billows of a swelling sea, which produced a swimming in the head like sea-sickness,'' and he further mentions as a well-known fact, that the trees sometimes bent during the shocks to the earth, and touched it with their tops."* This rocking motion of the surface was likewise experienced by Darwin, in South America, who states, on the authority of Acasto, that the earth- quakes of that country extend three hundred, six hundred, nine hundred, and some of them even one thousand five hundred miles along the ooasf.t

That this motion is of the nature of an actual billowy oscillation of the crust, is likewise plainly indicated by the attendant phenom- ena, especially by the uniformity in the direction which the eartli- qnake takes, and by the opening of great chasms and fissures in the

♦ See LyelPs Principles, Boston edition, vol. ii., p. 880.

t See a paper by Darwin, in Transactions of Geological Society of London.

ground, parallel to eacb other, and perpendicular to tbe course of the shock or undulation. Thus it is recorded, that daring the earth- quake that shook the valley of the Mississippi, in 1811, the iohabit- ' ants felt the earth rise in great undulations, and that the ground opened in numerous parallel fissures, having a direction from north- east to southwest This close correspondence between the direc- tion of the cracks, and that which invariably characterizes our Appalachian axes or faults, is a remarkable circumstance, that well demands the attention of geologists. It lends a further probability to our hypothesis, which merely imagines a very much more ener- getic series of undulations to have occurred during the elevation of all this part of the continent. There is reason to think that this agreement in the direction of the forces at periods so remote, is not merely casual ; for it appears, from a statement of Michell, that of five considerable earthquakes, felt in New England before his time, three are known to have come from the northwest, and the other two are supposed to have had the same direction. Recent observa- tions in Scotland indicate that the earthquake which was there felt in October, 1839, consisted of undulations moving from northwest to southeast, or in a direction perpendicular to the strike of all the older axes of that country.

Of the manner in which the wave-like movements in earthquakes may be supposed to originate, Michell suggests, that large tracts of country may rest on fluid lava, which, when disturbed, may transmit its motion through the overlying crust; but he offers the foUowing as the explanation of the mode in which the undulations may take place : Suppose a large cloth, or a carpet, spread upon a floor, to be raised at one edge, and then suddenly brought down again to the floor ; the air under it being by this means propelled, will pass along, till it escapes at the opposite side, raising the cloth in a wave all the way as it goes. In like manner, a large quantity of vapor may be conceived to raise the earth in a wave, as it passes along between the strata, which it may easily separate in a horizontal direction, there being little or no cohesion between one stratum and another. The part of the earth that is first raised, being bent from its natural form, will endeavor to restore itself by its elasticity, and the parts next to it being left to have their weight supported by the vapor which will insinuate itself under them, will be raised in their turn, till it either finds some vent, or is again condensed by the cold into water, and by that means prevented from proceeding any further.'' Now we conceive that there is a simpler view of the origin of the undulation, and one which is more in accordance with sound dynamical considerations, and with all the recorded observations upon earthquakes. In place of supposing it possible fur a body of vapor or gaseous matter to pass horizontally between the strata, or even between the crust and the fluid lava upon which it floats, and with which it must be closely entangled, we are inclined to at- tribute the movement to an actual pulsation Qneudered in the molt-

Miohell, PhU. Transaotlons, 1760.

en matter itself, by a linear disruption under enormons tension, giving yent, explosively, to elastic vapors, escaping eitiier to the surface, or into cavernous spaces beneath. According to this aup- position, the movement of the subterranean vapors would be to- ioardsy and not from the disrupted belt, and the oscillation of the crust would originate in the tremendous and sudden disturbance of the previous pressure on the surface of the lava mass below, brought about by the instantaneous and violent rending of the overlying strata.

It has been denied by some — and the objection seems to be ac- ceded to by Mr. Lyell— that the so-called wave-like moiion of the surface in earthquakes, has any strict analogy with the undulations of a fluid." On the other hand, it has been suggested, that a vi- bratory jar may be produced at a considerable depth, by a sudden fracture of the solid crust, and that the vibrations may be propagated upward through a mass of rock, even several miles thick. The first vibration which reaches the surface will lift the soil, and then allow it to sink again ; immediately after which another, which may have radiated from the same deep-seated point, may arrive ai a contigu- ous spot on the surface, and cause a similar rise and fall, and so others in succession, giving rise to a progressive motion of the ground, very similar in appearance to a wave of the sea," ♦

To the suggestion of a propagated vibrating jar being the cause of the rocking of the surface, we will reply by simply referring to all the authentic accounts of earthquakes, in* which the regularly progressive march of the billowy undulation is so frequently de- scribed by eye-witnesses, and likewise to the statements of Michel), who gives, from abundant data, the verp rate of the passage of the great Lisbon earthquake, across an area exceeding three thousand miles in breadth. As regards the other supposed difficulty, that the radius of each superficial curvature must be very small, we contend that this is by no means a necessary inference from the phenomena, since if we take into consideration the prodigiously high velocity with which earthquakes seem to move, we tind a reason at once, why tall objects, like trees, may rock from side to side with a rapid os- cillation, while the wave which disturbs them may possess an enor- mous breadth. A low and broad wave, if moving slowly, would only tilt the objects under which it might pass, into attitudes per- pendicular to its gentle slopes, but the lowest and broadest billow, passing with the amazing speed of the Lisbon earthquake, might, by suddenly shoving the foundations or pedestals of objects from beneath them, and as suddenly pushing them in the opposite direc- tion, cause them to swing rapidly through arc of almost any extent.

While the evidence, therefore, seems ample, of the existence of a wave-like motion of the earth's surface during earthquakes, facts are not wanting which indicate the recent production, from this cause, of permanent anticlinal axes. Thus we find, in Darwins Journal of Travels in South America, the following interesting statement :

♦ LydPs Principles, Boston edition, vol. II.

Mr. Gill, an engineer, mentioned to that intelligent traveller, that following op the bed of a stream, strewed with sand and gravel, and showing in one place, a channel in the solid rock about forty yards wide and eight feet deep, he fonnd himself suddenly going dovtn hill, the whole descent amounting to forty or fifty feet uf change of level. Here there was a decided arching of the surface, by which the river had been displaced from its ancient valley. Oc- curring in Chili, in a country so frequently visited by earthquakes, there can be little doubt as to the origin of this local anticlinal flexure in the earths crust.

We are inclined to regard the Ullah Bund as another example of an anticlinal axis formed in modem times by an earthquake. According to the description and map furnished by Mr. Lyell, in his admirable account of earthquakes contained in his Principles, this is a long elevated mound, extending from east to west across the eastern arm of the Indus, near the fort and village of Sindree. It is upwards of Jifty miles in lengthy and runs parallel to a line of subsidence along which the previously low and perfectly level plain around Sindree became permanently flooded. It is conjectured to be, in some parts, sixteen miles in width, and to have a height above the original level of the delta, of ten feet, which it seems to preserve very uniformly.

Of the Datb of the Appalachian Axes.

It has been stated already, that, excepting in one or two locali- ties, the Appalachian formations constitute an unbroken succession of conforming strata, from the lowest members of the sv stem, which repose immediately on the primary or metamorphio rocks, to the highest of the carboniferous strata. We must therefore conclude, that the elevatory actions, which lifted the entire chain above the level of the ancient sea, and impressed upon it those symmetrical features of structure which we have described, could not have be- gun, at least with any degree ot intensity, until the completion of the carboniferous formation. That the principal movement imme- diately succeeded the termination of this period of gradual opera- tions, or more properly arrested the further progress of the coal- formation, is, we think, clearly proved, by the fact, that nowhere do we meet with any strata, referable to the next succeeding or new red sandstone period, overlying the highest rocks appertaining to the coal ; and it can scarcely be supposed, that throughout so vast an area, embracing several enormous basins, in which the upper car- boniferous rocks have been preserved, all traces of that newer group, if deposited, should have been so entirely swept away, as not to have left its fragments even in any part of the wide tracts ovei* which the coal-rocks are spread. An additional reason for believ- ing that the elevation and flexure of the strata did not take place as late as the era of the new red sandstone, is to be found in the re- markably undisturbed manner in which a set of rocks of the age, approximately at least, of the European new red group, rest nncon-

formablj on the axes wbicb traverse the Appalachian formations. All the geological relations of these overlying rocks, occupying a very prolonged belt to the southeast of all the carboniferous strata, but especially those of tbeir organic remains, would seem to ally them closely to the new red sandstone group of Europe, and prob- ably to its newest division. Extending almost continuously in a narrow belt from the valley of the Connecticut, to beyond the southern boundary of Virginia, these strata neither contain any axes of elevation, nor do they exhibit even a conformity of strike with the neighbouring Appalachian and metamorphic rocks ; and, although they repose, throughout a great part of the belt, immedi- ately on the folded and inverted older strata, they furnish not the slightest indication of having been disturbed by the movements which produced the numerous axes beneath. We may hence confi- dently infer, that the great undulations which elevated those older formations, from the metamorphic to the carboniferous rocks inclu- sively, were antecedent to the deposition of these newer beds, and therefore that the age of the axes has been correctly determined to be antecedent to the commencement of the new red sandstone period.

That few or none of the principal Appalachian axes originated before the last of the coal strata were deposited, is demonstrably proved by the almost universal conformity or parallelism of all the strata. It is only necessary to consult the several sections appended to this paper, to recognize the important fact, that from the earliest to the latest of these Paleeozoio rocks, extending probably some- what further back than the Silurian formations of Europe,* and terminating with the last layers of the coal, no permanent Hexures or other disturbances of the crust occurred, to interrunt this continnous and amazingly prolonged succession of parallel de- posits.

In thus confining the era ot the principal movement which ele- vated the Appalachian chain to a comparatively short period, at the very close of the carboniferous formation, we are far from implying that a few local elevations, and many minor oscillations of the surface, unattended by permanent flexures, did not occur previously to this final, and beyond all comparison, most energetic effort of the subter- ranean forces. The unconformable superposition locally, of the Uel- derberg strata, upon the Hudson river slates, in the vicinity of tbe town of Hudson, is a sufficient evidence that even at an early period in the history of the Appalachian formations, this part of the region was disturbed by a considerable movement of the strata already de- posited ; and there are indications that similar agitations of the Ap- palachian territory, but to a much feebler extent, were experienced at the same and at other periods, during the progress of these for- mations. But, with the single local exception spoken of, none of these disturbances appear to have interrupted, however partially,

See a paper by Conrad, in Journal Academy of Natural Soionoe, vol. 8, part 21*

the perfect general conformity of the strata thronghout the whole Appalachian system. The occurrence of feeble movements, from time to time, in the earlier ages of the long Appalachian period, is clearly proved hy the presence of fragments of older strata, en- closed in the next sacceeding beds, and also by the coarseness of the materials of which some of the formations largely consist. The phenomena of the coal-measares, at the same time, go to show, as one of us has attempted to argue in another paper, that these move* ments continued to increase in frequency and power as the Appa- lachian period drew near its termination ; the entire coal-formation being the result of alternate quiet accumulations, and sudden parox- ysmal movements, terminating in that stupendous train of actions, which lifted the whole Appalachian chain from the bed of the ancient sea.

The obvions agreement in point of date, between this, which was incomparably the most energetic and extensive change in the physical structure of North America, and the wide-$(pread revolu- tion, which raised the European coal strata from the aqueous bed in which they were deposited, is a result of the highest interest in the comparative geology of the two continents. It would seem that the movement which produced so general and sudden a cessa- tion to the progress of the coal strata, led to grander changes in the earths surface than any disturbance since. Those displacements of land and sea, which severally terminated the Silurian and Devonian systems in Northern Europe, great as they truly appear, were, after ail, but local events; not extending, except in their indirect conse- quences, to the distant Appalachian shores, and, it would seem, hardly to the oceanic tracts of the European basin in Russia. Over how wide a limit these movements were decidedly influential in the organic world, mnst soon become a problem of the highest interest to our science.

Analogous Pbenomexa of Axes in otheb Countbies.

A perception of the important and novel bearings of the carious laws of structure here described, upon many points in geological dynamics, has led us to examine, with deep interest, the valuable and accurate labors of Fitton, Martin, De la Beche, Dumont, Murchison, Sedgwick, Weaver, Hopkins, and other eminent European geolo- gists, in the expectation of finding in the phenomena they describe, evidences of analogous laws.

While studying, with this view, such memoirs, sections, and maps as were within our reach, we have enjoyed no small gratifica- tion in discovering, what we consider numerous striking proofs of the prevalence of similar stnictural features in some of the most interesting geological regions in Great Britain and on the con- tinent.

Among these we would first mention the peculiarly interesting districts of Wales, to which the admirable reseaches of Messrs. Sedgwick and Murchison have, of late years, imparted so high a ge-

ologiofd importance. In the beantifnl and elaborate work of the latter geologist, the publication of which forms one of the great eras in geological science, we think we discern very distinct proofs that the Cambrian and Silurian axes of Wales possess similar strnc- tnral features with those of our Appalachian chain. While the older strata of the Berwyn mountains, as described by Mr. Marchi- son (Silurian System), would seem, by their altered character, and frequently inverted dips, to mark a close proximity to one of the great lines of disturbance of the district, that lying towards the northwest, from which has been propagated a combined uplifting and tangential force ; the contour of the undulations, lying more towards the southeast, when unaffected by faults or local disrupting action, exhibits a general conformity to our law of a steepening flexure, on the side towards which the movement has proceeded. As illustrations of tliis law, we would beg to refer the reader to a few of the beautiful sections appended to Mr. Murchisons work on the Silurian System.

First. Plate 81, fig. 6. Section across the Ludlow and Brecon anticlinal, exposing the valley of elevation of Wigmore lake.

Second. Plate 84, fig. 8. This exhibits, to the northwest, the lower Silurian on end for some distance from its contact with the Cambrian, after which it passes by a bold sigmoid flexure, in which the southeast dips are tery $teep beneath the upper Silurian.

Third. Plate 34, fig. 7. Shows, on the northwest, inverted Jlex- ures or foldingn in the Llandeilo flags, then steep southeast dipping Caradoc sandstone, and following this, the Upper Silurian and the Old red, with gradually diminishing dips. Fig. 8, of the same plate, presents analogous phenomena, though they are less distinct.

Fourth. Plate 34, fig. 9. Displays an interted and folded fie nre, succeeded by steep southeast dips, in the fiagstones of the Cambrian, following which are two normal arches in the lower Silurian.

To these Sections may be added the Vignette, page 359, present- ing an axis in the Cambrian rocks of Caermarthenshire.

In the eastern portion of this district, bordering the Malvern hills, the flexures would appear to be related, according to the same law, to the great line of elevating action, extending in a north and south direction through that region. The steeper sides of the arches are now towards the irest and the lower rocks are often ov<Jrtumed, so as to dip towards the east, thus exhibiting a direction of flexure, nearly opposite to that of the strata near the Berwyh chain.

As examples of these phenomena, we would refer to Plate 86, 8, presenting a transverse section of the Malvern and Sedbury hills, and figs. 9, 9b, 10, of the same plate, exhibiting the structure of the Woolhope axis.

The same general structural features, will, we confidently be- lieve, be found to prevail in the perplexing stratification of those parts of Devonshire and Cornwall, which, of late years, have drawn out much earnest theoretical discussion among British geologists. An inspection of the sections accompanying Sir H. De la Beohe's

elaborate Report, those, for example, from Combe-martan to Bolt- hill, and from Linton to Bideford, and a careful examination of the descriptions of this renon, given by him in that work, and by Messrs. Sedgwick and Murchison, in their verj able memoir On the Physical Structure and older Deposits of Devonshire, induces us to venture the prediction, that, throughout the region to which they refer, the phenomenon of folded axes will be found of very extensive occurrence, and that this folding and Inversion, together with the general law of steepening flexure in a particular direction, will explain the frequent repetitions of certain groups of strata, and assist in removing much of the obscurity that still hangs round the intricate geology of some parts of that ditriot.

Similar indications are, we think, presented in the structure of the southern and southeastern parts of Ireland, as described by Weaver, Griffith, Hamilton, and Austin. Among these may be in- stanced the great predominance of southern dips, those to the north being only occasional and of short continuance; a result, in our view, naturally arising from a succession of folded and steeply nor- mal flexures, due to a pulsatory movement propagated from the south. The evidences of such foldings and inversions are, we think, quite observable, in the account given by Mr. Weaver, of the parallel bands and patches, in chellon, of the older limestones, while the steepened dii), and extensive folding and inversion among the higher rocks, resulting from the same forces, are strongly im- plied in the section given by the same author, through the Dromagh eoal-field.* Similar phenomena would seem to be referred to, also, by Mr. Austin, when in speaking of the neighborhood of Water- ford, he ascribes the numerous contortions of schistose rocks, con- sidered by him as being of the age of the Silurian, to exeeseire lateral preemre.f

From the delineations and descriptions of the structure of the Alps, and more particularly of the Jura, which we have met with, we are led to believe that precisely similar structural features pre- vail in those disturbed chains. The various sections, illustrative of M. Thurman's work, " Essai sur les Soulvements Jura-siques,' may be appealed to as furnishing conclusive proof, that the axis planes of the numerous parallel anticlinal and synclinal axes of the Jura, are in every case oblique, and that they dip, in a great majority of in- stances, south-southeast, or towards the Alps.

Belgium, and the Rhenish provinces, seem to exhibit features of structure strikingly analogous to those of our Appalachian chain ; and we think we do not go too far, when we aflSrm, that in those extraordinary derangements and disturbances,' and those almost incredible phenomena of dislocation, contortion, and inversion,' re- ferred to by Dr. Buckland, as having been so ably elucidated by M. Dumont, we clearly recognize some of the general laws described

♦ See Memoir on the Geological Relations of the South of Ireland, by Thos. Weaver, Esq. Trans. Gt*6l. Soc. Lond., 2d Series, vol. V. t See proceedings of the Geol. Soc., London, No. 74.

in this paper, and made familiar by onr researches in the Appa- laobiaD belt. On this head we vonld refer to the obserrations of Messrs. Murchison and Sedgwick, contained in their memoir "On the Olassiiication and Distribution of the Older Rocks of Germany,*' of which an abstract is published in the Proceedings of the Geologi- cal Society of London. These distinguished geologists, when speak- ing of the groups of strata beneath the lower Westphalian limestone, thus desciibe the structure of the region northwest of the chain of the Taunus. For many miles south of the undisturbed range of the lower Westphalia limestone, the prevailing dip is about north- northwest ; the country round Seigen is regarded as a kind of dome of elevation, composed of the lower part of this series ; for, still further south, the dip is reversed to the south-southeast, and in a traverse from Seigen to the Taunus, across the strike, (a distance of about fifty miles), the same dip is continued, with very few in- terruptions. Considering their high inclination, this fact seems to give an almost incredible thickness to the deposits in questiott.i But the vertical sections do not give the order of superposition, for at Dillenburg, and on the Lahn, two great Devonian troughs are brought in among the older strata, without any general change of dip; and if we accepted the vertical sections as the sole proofs of superpo- sition, we must place the Devonian, and a part of the carboniferous series, under the chain of the Taunus.'*

If we are correct in our interpretation of the phenomena here described, they present an instance of structure which is of frequent occurrence in the Appalachian belt, where the rocks of the south- eastern portion of a synclinal flexure, are folded over into south- eastern or inverted dips, or where the axis-planes of both anticlinal and synclinal flexures are inclined very obliquely to the horizon, dipping in parallel directions to the southeast. The chain of the Hundsruck, and its continuation, the Taunus, of which they regard the Quartzite and Chlorite slates as " but altered forms of a great Silurian group, under the Eifel limestone,*' would thus appear to occupy a similar position to that of some of the ridges on the south- eastern margin of the Appalachian region, where we meet with very similar phenomena of alteration, accompanied by a large amount of intrusive matter, and aacent to this, on the northwest, many in- versions and foldings of the strata. Including, in one view, the por- tions of Belgium, the Rhenish provinces, the Westphalian coal-field, and the Hundsruck, Tan n us, and Hartz ranges, described by those geologists as displaying an extended series of Cambrian, Silurian, and Devonian strata, we are strongly of opinion, that the relations of dip which they present, will be found reducible, in great part, to the laws of structure we have endeavored to develope, and fairly referable to a similar undulatory movement directed towards the northwest.

From the observations of Dr. Fitton, on the structure of the Wealden and associated formations, as detailed in his admirable memoir on the Strata below the Chalk, and likewise from . the more recent investigations, in tlie same region, by Mr, Hopkins, of which

a sammary is to be seen in the proceedings of the Geological Soci- ety of London, for 1841, it would appear, that in the districts of tbe Wealden and Baa Boulonnais, the namerons aies observe a curved form, and are nevertheless parallel to one another. Mr. Hopkins, after describing several of these flexures, states, that all these lines preserve a remarkable parallelism with each other, and with the carved central axis of the district." It would further appear, from the observations of these distinguished geologists, unless we have given an erroneous interpretation to their sections aud de- scriptions, that a great number, if not all of these axes, present a much steeper dip on one side than on the other, and that this stronger inflection generally occnrs on the same, to wit, the northern side. Speaking of the line from Famham to Seven-oaks, Mr. Hop- kins uses these words : It is a line of flexure,* with a great dip to the north, but without the cx>rresponding dip to the south, neces- sary to form an anticlinal arrangement, except in one or two lo- calities. Towards the west, it runs immediately at the foot of the Hogsback, with a dip, which, near its western extremity, amounts to seventy or eighty degrees." "Tracing it towards the east," he adds, that, " at some points the line assumes a distinct anticlinal character."

Dr. Fittonjn describing the interior of Kent (page 184 and 185), gives several drawings of sections of this or an adjoining axis, in all of which the predominance of the dip on the northern side is dis- tinctly marked. Alluding to one of these sections, he says: "Both sides of the saddle are visible within a few paces ; the beds on the north rising at an angle of about sixty degrees, while on the south, they decline at an angle of forty-flve degrees." As illustrating the same law, we would more particularly refer to the following colored sections appended to Dr. Fittons memoir :

First. The section across the Weald, from the South Downs, "Western Sussex, to the Surrey hills. In this, the dip, on the northern side of the great axis, is represented as slightly greater than on the southern side.

Second. The two combined sections, along the southeastern and southwestern coasts of the Isle of Wight. The axis traversing this island, and continued to Pnrbeck, is represented on the map accom- panying the memoir of Dr. F., as parallel with that of the Weald. The sections referred to cross this axis, and exhibit a much greater steepness of dip on the northern than on the southern side.

Third. The three sections across the vale of Wardour, trans- verse to the axis of that region. In all of these, the preponderance of dip on the northern side is very great.

This series of curved or undulating axes, which are, in the main, parallel to each other, would thus appear to manifest laws of

By the term flexure, as explained by the phrase one-sided taddlet used in the same connection, we infer the auUior to mean, what we denominate (m- Uue flexures while he restricts the term anticlinal, to those bondings which give, approximately, equal dips on tbe opposite sides.

stracture, strictly analogoas to those of our Appalnchian region ; and they serve still farther to confirm ns in onr belief of the preva- lence of siniilar features, among the fieznres, in all regions of ex- tensive disturbance, as well as to increase our reliance on the just- ness of the theoretical views by which we have attempted to ex- plain them.

In ooDclusion, we wonld express our belief, founded on the phenomena referred to in this memoir, and on nnmeroua similar geological facts, of recent as well as ancient date, which cannot be mentioned in this place, that all great paroxywmal aeti&fu from the earliest epochs, to the present time, have been accompanied by a wane-like motion the earthB cruet*

The Age

Ov The

Coal Rocks Of Eastern Virginia.

On the Age of the Coal Eocks of Eastekn VntoiNiA.

FftOM TbAXSACTXONS of TDK ASSOCIATION OF AmKSICAII QbOLOGISTB AND KaTUSAUBTS,

1840-1&12.

The formation here referred to, overspreads parts of Ohesterfield, Powhatan, Amelia, Henrico, Hanover, and Goochland conntiesi ly- ing in basins of granite and gneiss, the principal coal seams being separated by only a few feet, and sometimes by bat a few inches, of carbonaceous shale from the floor of primary rock. In some places near the eastern margin of the field, where it has been most extensively explored, the thickness of this group of strata is about eight hundred feet, but towards the centre of the principal basin it is probably somewhat greater. Throughout much of this depth the strata consist of coarse grits, composed of the materials of granite, so little worn as to have the aspect of this rock in a decomposing state. The coal, which in the northern parts of the field is divided into two and sometimes three distinct seams, separated by consider- able intervals of slates and grits, but all comprised within the lowest one hundred and fifty feet of the series, is in the more productive region, south of the James river in Chesterfield county, collected to- gether into one immense stratum, which, though of very variable thickness, may be generally stated at from twenty to forty feet.*

The curious circumstance, of the grits and coal-bearing strata of this region resting immediately on a floor of granitic and gneissoid rock, appears early to have attracted notice, and connected with the fact, that the coarser sandstones are but the recemented materials of the adjoining primary masses, almost unmarked by aqueous wearing, seems to have led to the prevailing belief of the very high geological antiquity of these deposits. Such considerations, and others, chiefly lithological, would appear to have formed the grounds upon which the distinguished pioneer of American Geology, Maclure, founded his ref- erence of this remarkable series of grits and carbonaceous strata, to

For a particular acoount of the boundaries and contents of this ooal field, the composition of its numerous varieties of coal, and other details, see Re- ports of Geological Survey of Virginia for 1836, 1840. Also, " Memoir of a Section i>as.sing through the Bituminous Ooal Field near Richmond," by Rich- ard C. Taylor. A more copious and accurate account will hereafter appear in the final Report on the Geology of the State.

the period of the old red sAndstone. More recently, Mr. R- C. Taylor, in an interesting paper relating to this region, in the Transactions of the Geological Society of Pennsylvania, expresses himself as rather inclined to assign this independent coal formation to the transition carhoniferous deposits, tlian to the secondary class, on the ground of the absence of any " analogy " between it and the latter, throughout the whole series of saperincumbent strata.*

The further explorations in this region, made in the course of the Geological Survey of the State, aided by new and extended mining operations, having brought to light, more clearly than be- fore, many interesting organic remains, chiefly of vegetable origin, have aflTorded me the opportunity of accumulat'.ng important data for determining the epoch of this isolated and remarkable coal forma- tion. In the absence of such a guide, and judging by lithological indications alone, perhaps no more probable conclusion would have been reached on this subject, than that of the able geologists whose names have just been mentioned.

These vegetable remains, a qroup bear a striking resemblance to those which accompany the Oolite coal of Brora, Whitby, and other European localities. Some of them, as, EquUetum colttmnare Calamites aranaceus PeeopUru WhithientiSj Pecapteris Munsteriana and Lyeopoditea tincifolius are, I think, speciflcally the same with the European fossils, while the rest, among wliich are TamiopterU magntfolia an unnamed Peeopteru and two or perhaps three species of ZamiteSy are very closely allied to certain species of the same genera, found in connection with the Oolite coal of Yorkshire, Sunderlandshire, and other places in Europe.

The most abundant of these remains are, the EqtiUetum colum- nare, also said to exist in great profusion at Brora and Whitby; a large species of Zamiteaf hereafter to be noticed; and a magnificent Taniopteris {T, magnifolia) very closely analogous to T. mttaia and seitaminea of the Yorkshire and Sunderlandshire formation. These four being found in vast numbers immediately upon, and in- terlaminated with the coal, where it is slaty, would appear to have furnished the principal materials of the stratum. No remains bear- ing any resemblance to Stigmaria have been discovered either in the soft carbonaceous slates beneath, above, or in tlie midpt of the seams, or in the other slaty and gritty strata of the series.

With such a striking agreement, as regards not only the general character of the vegetation, but the individual plants .belonging to the rocks now under consideration, and those of the Oolite coal of Europe, it can scarcely be doubted that they were formed during the same or very nearly the same geological period, and I therefore feel no hesitation in referring the coal of Eastern Virginia to a place in the Oolitt system on the same general parallel tcith the carhonaeeous beds of Whitby and Brora — that is, in the lower part of the Oolite group.

This determination possesses, I conceive, no small degree of in- terest in its connection with our geology generally, inasmuch as it supplies a very important link in the great geological succession of

Ibrmations, which had not previously been discovered anywhere with- in the United States. Nor is its importance when connected with the strildng discovery of Oapt. Grant, of an Oolite coal-series in the opposite hemisphere, near the mouth of the Indas, some of the fossils of which appear to be almost identical with plants, from the Virginia coal rocks, hereafter to be described.* With these dis- coveries in view, it can scarcely be doubted that thQ fossil Jlora of even the middle geological periods has sufficient uniformity of char- acter, even in opposite parts of the globe, to furnish a very useful guide in the comparison and identification of great geological groups.

Of Animal remains, so abundant in the Oolite generally, the only traces yet discovered in the Oolite coal series of Virginia con- sist of teeth apparently Saurian, recently found by me in and a little above one of the coal seams in the northern part of the district, and the scales and sometimes entire impressions of a slightly Heteroeercal fish, referred to, doubtingly, by Mr. Nuttall,t many years ago, and lately examined and named by onr able ichthyologist, Mr. Redfield.

The coarser roc1i:8, lying above the carbonaceous strata, and form- ing the greater part of the thickness of the series, contain very few organic remains, and those in so imperfect a condition as to have little or no value for purposes of comparison. There are, however, Btrong reasons for believing that these strata, by a gradual transi- tion, pass upwards into the series of felspathic sandstones, described in my Report of the Geological Survey of Virginia for 1840, under the title of Upper Secondary Strata. The latter, considered by Messrs. Taylor and Clemson, as of 'secondary origin, perhaps coeval with the Oolites," have since been referred by myself and Prof. n. D. Rogers, to the upper part of the Oolite series, so that this great division of the geological column, though still perhaps very imperfectly represented in the United States, comprises a thick- ness of considerably more than one thousand feet of strata.

I may here incidentally remark, that certain fossils (Posidonomya Keuperil <tc,) which I have recently found in a particular division of the new red sandstone {Middle Secondary) of Virginia, have led me to infer the existence in that formation, of beds corresponding to the Keuper of Europe. A more particular account of this dis- covery is reserved for a future occasion.

The following descriptions of .some of the principal fossil .plants, found in connection with the Oolite coal of eastern Virginia, are the results of a careful comparison of the specimens with the figures and descriptions of analogous fossils, in Sternberg, Brongniart, Brown, Lindley and Hntton, Phillips, and the Memoirs of Murchi- son, Grant, and others relating to the subject. These, with others not yet ready for the press, will, I trust, fully sustain my conclusion

See " Memoir to illustrate a Geological Mai> of Cutch." By C. W. Grant, Esq., TnuiB. Geol. Soc., Lond., Vol. v.. 2nd series.

i See Trans. Acad. Nat. Sciences, Pniladclphia, VoL 9.

as to the age of the remarkable coal-formatioD under oonridera- tion.

The details which they include, tliough inconaietent with the elegance of technical description, together with the acoompanjing Plate, will, it is believed, facilitate a jast comparison of these fossils with those of the Oolite coal-formation elsewhere.

mm

Fossil Plants of the Oolitr Coal Books of Eastern Yib-

Ginla.

Equisetuh coluhkabb. Brongn.

Oncylogonatam earbonaHum, Koenig. Equisetites eolumnatHs. Stern- berg.

The fossil referred to under this title, occurs very abundantly in certain slaty and argillaceous rocks met with at nearly all the open- ings in the coal-fields, both north and south of the James river, and appears to have formed one of the chief sources of the material of the coal beds. The specimens in the Blaty rock are generally flat- tened out parallel with the laminie of the slate, and from the con- version of the vegetable matter into coal, give rise to alternations of coal and slaty material, sometimes as numerous as thirty in an inch. On one of these masses of slate in my collection, there is a beautiful impression of a part of the Equisetum, about fifteen inches long, and where widest, seven inches broad, comprising ten distinct articulations, the intervals of which regularly diminish from one extremity of the fossil to the other. Specimens of this fossil are also met with in a dark bituminous clay, and a light brownish, soft sandstone, both of which occupy a place near the coal. In these the rotundity of the stems is pretty well preserved, the rocks im- bedding them being destitute of the laminated structure.

The flattened as well ns the convex impressions agree exactly with the figures appended to Murchison's Memoir on the coal field of Brora, Trans. Geol. 8oc. of Lond., Vol. II, Part II, and corre- spond in every particular with the description of the Brora fossil as given by Eoenig in this memoir. The acute regular furrows of various lengths, gradually diminishing in width, and running out into linear grooves, and " the elevated rays or ribs having a pretty acDte ridge, and gradually tapering into a fine, more or less length- ened raised line, referred to by Koenig, as impressions produced by the flattened stem of the Oneylogonatum, and represented in figures 3 and 4, of Mr. Murchisons Memoir, are facsimiles of the Virginia fossil, as it occurs in innumerable layers in the slaty rocks, or is impressed on the parting surfaces of some varieties of the coal. Nor is the resemblance less perfert between the uncompressed form of the Brora fossil as represented in figures 1 and 2 of the Memoir, and the cylindrical jointed stems marked near the joints with simi- lar grooves and ribs, already alluded to as occurring in certain soft sandstones and argillaceous beds in the Virginia localities. I have

therefore no hesitation in considering the Virginia fossil as identical with that of Brora, as well as with that referred to hy Prof. Phil- lips in his Geology of Yorkshire, as occurring in the sandstone at High Whithy, and recognized bj him to be the Brora fossil. Gnided by the anthoritj of Brongniart, who describes specimens from Brora, AVhitby, and other European localities, I shall hereafter speak of our fossil as the Equiaetum eolumnare.

In all the British localities of this fossil, as Whitby, Haibume, Wyke, and Brora, it occurs in connection with carbonaceous beds appertaining to the lower Oolite, In the neighborhood of Balbronn, Gemonvel, Studtgord, and other localities on the Continent, it is found in geological connections less certainly determined, but which Brongniart inters to be the same as those in which it occurs in Great Britain. In closing his aoconqt of this fossil, Brongniart says : In England, where the secondary formations have been so well studied, no trace of this plant has yet been found in the lias, or in the more ancient beds, or in the Oxford clay and more recent formations ; nor does any thing in the Stonesfield limestone or Til- gate limestone, indicate the presence of this plant, which we may therefore eonsider as characterizing the lower beds qf the Jura lime- stone " (the Lower Oolite,)

Equibetum abundinifobuk.

The fossil for which the above title is provisionally proposed, bears a close resemblance to the stem of a common reed, braised and flattened by pressure. The most perfect specimen in my pos- session is on a light gray, slightly micaceous slate. The stem, which is flattened out, is fifteen inches long, and two and a half to three inches wide, divided by joints about four inches asunder. The sur- face, though entirely destitute of regular ribs or strisB, is marked, especially in the vicinity of the joints, with low, short, triangular plicatures, apparently due to compressing action. At the joints, which are beautifully distinct, ana over much of the surface, the slaty matter is covered with a siliceous coating of a lighter color and much greater hardness than the body of the rock, derived ap- parently from the joints and epidermis of the plant.

The lower and toothless joint, in Plate XaXI, fig. 8, Sternberg, representing Equieetites acutusy bears a strong resemblance to this fossil, as do also the reed-like stems represented along with im- jiressions of Zamitea heterophylluSj in Plate XLIII, figs. 4 and 5, Sternberg.

Calahites arenaoeus. Brongn,

The fossil referred to by this title is frequently met with in the coal rocks of Eastern Virginia, occurring both in the dark laminated slates, and in the soft, bluish- gray sandstones. In the former po- sition it is generally very much flattened, from compression between the layers of slate ; in the latter it is often quite cylindrical, being found in an erect posture in the rock.

On comparing some good specimens in my collection with Bron- gniarts figures and description of G, arenaceus, I am convinced that oar fossil is of this species, or one very closely allied to it, and that it diffeni in many important points from 0, Suekowii. The oalaroite from Eastern Virginia, forwarded by Professor Silliman to M. BrongDiart, and by the latter figured as 0. Suekowii was ob- viously, as he hunself confesses, a very imperfect one, and as will be seen by inspecting his drawings, differs in many respects from the other specimens, referred by him to the same species, all of which were derived from the true carboniferous formation. From Brongniart*s drawing of the Virginia specimen, and his statement that it is nearly or entirely destitute of tubercles at the joints, in which it strikingly differs from the true 0, Suekowii and agrees with the arenaeeus I am fully convinced that the fossil figured by him as a variety of G, Suekowii is the same as that I am now de- scribing, and is the true Galamites arenaceus.

It may, perhaps, be conjectured, without doubting the great skill of this iUustrious naturalist in vegetable Palssontology, that the specimens from Wilkesbarre and Richmond, being presumed by him to have come from the same geological formation, and the very im- perfect condition of the Virginia specimen disguising its peculiari- ties, he failed in bestowing such attention on the subject as would have assured him that the two were of different species.

According to Brougniart, the G. arenaceus occurs associated with Equisetum eolumnare, near Studtgard.

Cala.Mite3 Planicostatub.

The fossil here referred to is usually met with in the platy beds con- taining Equisetum columnare and is, in some localities, quite as abun- dant as that plant The best characterized specimen in my collection has the appearance of a flattened stem, exhibiting several distinct articulations, all entirely devoid of tubercles. Throughout its whole length, this impression is marked by shallow parallel grooves, slightly deepening towards the joints, and distant from one another from the fifteenth to the twentieth of an inch. These grooves are generally prolonged across the joints, so as to be continuous throughout the neighboring divisions of the stem, suffering only a slight flexure and lateral displacement as they cross the articulations, and returning again to the original line. The ribs or ridges between the grooves are smooth and flat, excepting near the joints, where they are slightly but irregularly convex. At many of these joints, are seen small circular scars, like the points of insertion of leaves, arranged at intervals of about half an inch. One or two ex- tremely fine stria) may generally be traced along the middle of each rib.

From the general flatness of the impression, and the great shal- lowness of the furrows, it might at first be readily taken for a large striated leaf; but, upon removing the coaly film wliich conceals the articulati(m, the jointed and stem -like nature of the fossil is indis-

tinctlj shown. The great thickness of the coaly lajer adjoining this impression upon the surface of the slate, and the number of such impressions found in the layers of a fragment of the rock only one or two inches thick, imply that the hollow stem of the plant which produced them, was extremely thin, and easily compressed. Whether it was of the same genus with the plants whose fossil relics have been arranged under the title of calamites, it would be impossible as yet to determine. As far as may be inferred from external appearances, it would seem to be referable to that group. Ranking it therefore, for the present, with the Umg list of dtmbtful fossils included under this generic head, I propose the specific name of planicottatti as descriptive of the remarkable flatness of its ribs.

TiEmOPTEBIS MAGNIFOLIA.

The impressions of this superb plant are found in great numbers in some of the dark gray slaty layers and ferruginous bands above the coal, and even upon the surfaces or partings of certain varieties of the coal itself. This fossil retains so perfectly the delicate mark- ings of the original frond, that I have been able to compare it satis- factorily with the other species of the same genus, figured and de- scribed by Brongniart, Phillips, Lindley and Button, and Sternberg, and have hence been led to consider it as a new species. The partic- ulars in which it differs from the TaeniopteTis vittata Brongn. and T. aeitaminea (Presl.) Sternberg, the two species which it most nearly resembles, will appear from the following description :

i. Tk6 farm of the frond. Although among my specimens there is no large frond, in which both the extremities are entire, the numerous fragments of fronds, exhibiting the ends as well as the middle portions of different leaves, enable me very satisfactorily to trace the figure of the frond, in an advanced stage of growth. This may be described as oval-lanceolate, but with this peculiarity, that while the upper or free end is formed by a gradual curving of the margin, from the wide part of the frond toward the end, so as to present a very regular and nearly elliptical sweep, the lower ex- tremity tapers towards the petiole, in a somewhat irregular and undulating manner, and is greatly reduced in width before it termi- nates. Our fossil thus agrees with the T, vittata in the elliptical outline of the upper half of the frond, but differs from it in the un- dulating margin and more triangular form of the part next the peti- ole. It is also wider in proportion to its length. It is at once dis- tinguished from the T, 8citaminea, which in other respects it very closely resembles, by the apex of the latter having a re-entering, cor* date curvature.

£, The $U6 of the frond, A comparison of the smaller and more perfect fronds with fragments of the larger ones, often amount-r ing to one half or three fourths of the whole, has enabled me to supply the outline of the deficient portions of many of the latter, and has thus afforded data for measuring a number of the fronds. The following are the dimensions of three, greatly differing in sixe;

Frond A. Breadth fi-4 incbes.

Estimated length by several fragments 14 Frond B. Breadth 4 "

Estimated length 24 "

Frond 0. Breadth 6-4 "

Estimated length 40

The breadtlis here recorded were all carefully measured npon the specimens. The length of A was deduced from the measured length of a fragment* twelve inches long ; that of B, from a fragment twenty inches long, and that of C, from several fragments, from six to twelve inches long. The estimated lengths of A and B, are probfr- bly a little less than the true lengths.

5. The Midrib and Petiole, The Midrib is quite robust, having, in some of the larger impressions, a width of from one third to one half an inch, but gradually taperiog towards the upper end, it be- comes extremely slender at the apex. On the upper side it is marked by a somewhat deep groove and numerous parallel strie. The Pet- iole is thick, rounded at the end, and about one seventh the length of the frond. This slendemess of the midrib towards the upper end, forms another feature of distinction between our fossil ana the T, tittata as figured by Brongniart, and in this particular gives it more resemblance to the drawing given by Lindley and Hntton of 71 ma- jor.

4- The Nerturee, As in the T, tittatu T. seitaminea, and a few other species, the nervures of our fossil are nearly or exactly at right angles to the midrib. They are, however, /br more delicate and numerous than in T. vittata. Moreover, after a careful exam- ination of the nervures of more than twenty fragments, I have been unable to discover more than three or four instances of their bifur- cation, either near the midrib, or at any other part of their length ; while on many large and distinct specimeos, not a single example of bifurcation could be found. Simplicity of the nervures is, there- fore, to be ranked as one of the characters of our fossil. In the 71 tittata on the other hand, according to Brongniart, " the nervures are sometimes simple, sometimes bifurcated either towards the base, the middle, or near tiie extremity ; " and in Brongniart's figure, the bifurcated nervures are as numerous as the simple ones, the two be- ing arranged alternately. In Sternberg's definition of the species, a similar frequency of bifurcation is implied by the words tents horisontalibus furcatis cum simplieibus (utemantibus,

6, The position and size of the supposed points of fruetifieatwn. On many of the fronds of the Virginia fossil an irregular row of circular depressions is seen, on each side of the midrib, and not un- frequently on the midrib itself. These hollows would seem, as in the vittata to mark (according to Brongniart) the position of the roundish groups of capsules. They are, however, much larger than in that species, being from one sixth to one fourth of an inch In diameter, and are placed at unequal intervals asunder, and at rather varying distances from the midrib.

The peculiarities above desoribed, especially the form and size of the frond, and the almost invariable singleness of the nervures, would seem to farnigh ample reasons for regarding the Virginia fos- sil as distinct from either the 7'. vittata or T. $citaminea, although nearly allied to both. Looking npon it as forniiog a new species, I have ventured to give it the title of magti\folia,

T, magntfolia. Frond, varying from one to six inches in width, and from seven to forty inches in length, curving elliptically towards apex, tapering with an undulating margin towards base, supported by a thick petiole abont one seventh the length of the frond, and rounded off at the end. Midrib thick, marked on the superior side by a somewhat deep groove and numerous parallel lines ; nervures

Serpendicular to midrib; simple, or very rarely bifurcated; parallel, istinctly prominent, and numbering, in the Large frond, from fifty to sixty to an inch.

The genuB TcBniopterU, entirely unknown in the carboniferous formation, first makes its appearance in the new red sandstone, and still later, forms, in the lias and dolite, an important and ap- parently characteristic group. The species most nearly allied to our fossil, namely, T, vittata, T. seitanUfua T, major, and T, lati- /olioy appear to be peculiar to the lower part of the dolite and the lias, either one or all of them being found in this geological position at Hoer, Neaewelt, Whitby, Scarborough, Stonesfield, and other localities.

Speaking of the HttatOy Brongniart says : This fern is one of the most common in the Jura formations, and may be regarded us one of the characteristic plants of our third period of vegetation. From a citation of localities, it appears that it has already been found in widely distant places, and that it is especially abundant in the Oolite marls of the coast of Yorkshire."

Pbooptbbis WnrrBiBNSis. Brongniart,

Although fossils of the fern tribe are of very rare occurrence in the strata of which I am now treating, I have been fortunate enough to procure several specimens in a good state of preservation. These I find to be referable to three species, closely resembling if not iden- tical with species found in the lower part of the Oolite in Europe. The fossil referred to under the present head corresponds so well with Brongniarts figures and description of P. Whitbiensia, that, notwithstanding a slight disagreement in one or two minor points, I cannot but regard it as of the same species.

The leaf is bi-pinnate, the rachis thick and smooth, the pinnas oblique, opposite, straight, much prolonged and tapering towards the apex. The pinnules are contiguous, but not confluent ; pro- tracted at the upper part of the base, contracted at the lower; they are arcuate-acute, but less so than in Brongniart*s figure of P. Whit" hiensis. The main nerve, starting from the midrib nearly at right angles, bends gradually upwards, the nervnles diverging slowly from this, or springing from the base near the central nerve, are once sod

twice furcated, and both they and the central nerve are very deli- cate. In most of these particalars, it will be seen that onr fossil agrees precisely with P. Whitbiensu, The only points of difference seem to be a somewhat less acute termination of the pinnules, their rather greater breadth in proportion to their length, and their more delicate nervation. These disagreements are, I pre- sume, too unimportant to separate the Virginia fossil from the P. Whiismisy especially when so high an authority as Sternberg has united under this title three of Brongniart's species, presenting much greater diversities, namely, P. WhitbiensiSj P. iteobenaii P. leneris.

The importance of this fossil, in determining the age of the strata in which it is found, may be inferred from the statement of Brong- niart, that this plant is altogether peculiar to the Jura formation, and has no analogy with any of those which appertain to the true carboniferous system.'

Pecoptems Munbteriana. Sternberg,

Of the fossil here referred to, I have met with but one specimen. This consists of a single pinna, with a full array of uncommonly large, and in general, distinctly marked pinnules. The extraordi- nary size of the pinnules, and their proximity and mode of attach- ment to the rachis, might at first lead us to regard this fossil as identical with the Pecapteru in8tgni$ of the Yorkshire Oolite, described and figured by lindley and Hutton; but a closer at- tention to the plan of nervation, and the form and size of the pinnules of the two, discloses very important points of difference. In the P. inngnUy each nervnre, at its junction with the middle nerve, very regularly divides into two branches. In the Virginia fossil, after this forking at the middle nerve, there occurs a further bifurcation of one or of both the branches thus formed. The pinnules of the P. inngnii are larger than those of our fossil; they are, moreover, of a falcated shape, while those of the Virginia species are nearly or quite straight, and have an ovate termination. Among all the species of Pecopteris described and figured by Stem- berg, Brongniart, and Lindley and Hutton, the P. Muruteriana is that with which our fossil most nearly corresponds. In the shape of the leaf, and its mode of attachment to the rachis, and in the peculiar plan of nervation, as shown in Sternberg's drawing of P. Muruteriana the agreement is perhaps as close as could be ex- pected, even in two specimens of the same species. The only point of difference between them, appears to be the greater size of the pinnules in the Virginia fossil. As, however, the disparity is not very great, and the smaller pinnules on the Virginia specimens are quite as large as the larger ones in Sternberg's figure, the inequality may probably be explained by difference of age or of position on the leaf.

According to Sternberg, the P. Mvneteriana occurs at Bullen- reit, near Baruth, in strata, referred to the lAae,

Pbooptkris.

This specimen consists of several incomplete pinnte, evidently appertaining to a large Pecopteris, of a different species from either of the preceding. The pinnas are straight, regularly tapering towards the extremity, nearly at right angles to the main stem, and closely crowded together. The pinnules arranged alternately on the oppo- site sides of the midrib, are nearly perpendicular to it, and are attached by the entire base, but quite separated one from another, having no connecting wing. The pinnules, near the base of the pinncB, preserve a nearly uniform breadth, from the attachment to near the extremity, and are then very bluntly rounded oif. Those more towards the end of the pinna are slightly tapering, curve a little upwards, and terminate acutely. A strong ridge marks the position of the middle nerve. Each pinnule is crowded with the impression of Sort, form- ing a row of dots, or of depressions, from six to twelve in number, on each side of the middle nerve ; but in no part of the specimen can the nervures be distinctly traced. Of the various species figured, that which seems most nearly to approach our fossil is the Pecop, obtuBifolia of the Yorkshire Oolite, as represented by Lind. and Ilntton, plate GLYIII, figs. 1 and 16. According to the description of these authors, however, the Yorkshire fossil is a much smaller and more delicate plant than ourt*.

Ltoopodites Wiluamsonis. Brongn, Prodromus,

Lycopodita unci/oliua, Phillips's Yorkshire.

The fossil impressions referred to this title, comprising different portions of the plant, among which are the head or cone, corre- spond in almost every particular with the figure of Lycop. vncifo- lius given by Lindley and Button, as copied from Mr. "Williamson. " The one, and sometimes two, strongly marked ridges up the cen- tre of each leaf," the oppositely placed leaves, with the smaller ones between,' the scales upon -the stems, the cones with strongly marked rhomboidal spaces like scars," the peculiar claw- like form of the leaf, especially where full grown, are all distinctly exhibited in the Virginia fossil. Indeed the only points in which it seems at all to differ from the figure of Z. unc\foliva given by Lindley and Button, are, that it is smaller in all its dimensions, has apparently a less scaly stem, and has its small leaves less sharply pointed, and less curved than the Yorkshire fossil. Considering these minor differences as affording no sufiScient grounds for rank- ing it as a distinct species, when in other respects the agreement is so striking, I do not hesitate to regard it as either identical with the Lycopodites uncifolius or as a species closely allied to that planC

Zamites obtusifolius.

The beautiful fossil which I propose to designate by this title, is found along with the Lycopodites above described, in a state of good preservation, in a dark-gray argillaceous slate, not far above

the coal. It has the form of fragments of the leaf, or pinna, one of which, in my collection, tliough still incomplete, is about eight inches long. The impression of the midrib is nearly straight, gradu- ally tapering towards the outer end of the pinna, and irregularly and rather finely striated. This, where widest, in the larger pinna above mentioned, is about one tenth of an inch across. The leaflets are attached to the midrib by their whole base, and where they unite with it are nearly in contact one with another, but not confluent. They are about one tenth of an inch wide, preserve a nearly uni- form breadth from the base outward, and are Muntly rounded uflt at the extremity. They are from one to two inches long, becoming shorter towards the upper end of the leaf, and are eitlier straight or slightly falcated. From the lower end of the leaf, to near the upper, the pinnules are placed at an angle of from seventy to eighty degrees with the midrib ; at the upper end they make a more acute angle. Each pinnule is marked by from three to six parallel veins, springing from the midrib, and running to the extremity. As yet I have met with no specimen exhibiting the stem and pinnsB in con- nection, and I am therefore unable to speak of the character of the stem to which these leaves belong.

On comparing this fossil with the figures given by Professor Phillips, and by Lindley and Qutton, of the several species of Cyai- dites or Pterophyllum, found in the Oolite rocks of Yorkshire, &c., it will be found, along with a marked general resemblance, to pre- sent several striking peculiarities. Kor does it bear even as near a specific analogy to the other fossils of the same tribe, figured and described by Sternberg.

The fossil which it most closely resembles is one which I find fig- ured among the illustrations of Captain Grant's interesting Memoir on the Geology of Cutch,' TGeol. Trans, vol. 5,) under the title of Ptilophyllum aeutifoliumr In the latter, however, the leaflets have an acute apex,' and are Mmbricated at the base, and attached obliquely," in all of which characters it differs from the Virginia fossil.

In accordance with the generic characters which appear to have guided Prof. Phillips, this fossil would rank as a Cyc€kiite8. while in obedience to the definition of Brongniart, and Lindley ana Hutton, it should be placed in the genus Fterophyllum, Preferring what ap- pears to me the simpler arrangement of the Cyeadites adopted by Sternberg and Presl, I have rather chosen to place it in the compre- hensive genus Zamites of the latter author, adding the specific name obtusifolius, as descriptive of the mode of termination of the leaflets. The propriety of referring it to this genus will at once appear on comparing the above description of the fossil and the accompanying figure, with that part of Sternberg's definition of the genus which relates to the leaves, comprised in the following words : " Folia pin- natifidaj vel pinnata, pinnis ditichia seasilibus adnatisve, laeiniiague inUgerrimu nervoais nsi'vi plurea parallel in haai pinnarum vel laciniarum jtucta depoaiti

It will be seen that the ZamiUa obttia\folitia, as above charao-

tensed, bears a close resemblance, in most particulars, to tbe fossil figured and described by Brongniart under tbe title of Filicitea vU iarioides, and since described by Sternberg as ZamiU$ blechnoidei. Vide Hist des Veg. Fos. : Liv. 11, p. 391, and Sternberg's Versnch, &c., part 7 and 8, p. 200. Tbougb this fossil is spoken of bj Bron- gniart as haTiDg been sent to him bj Prof. Silliman, from the coal- field of Eastern Virginia, I have been nnable to find it anywhere in this region. The points in which, according to the description of Brongniart, it differs from Z. obtui\foliu8y are the conflaent form of the pinnules where thej join the midrib, and the invariable pre enoe of but two nerves in each pinnule.

Zamites tenuistbtatus.

The impressions of this fossil, which I have thus far met with, are imperfect and rather obscure, consisting of diointed leaflets and incomplete fronds. They are, however, sufficiently distinct to show the peculiar form of the leaflets, their mode of attachment to the midrib, and their nervation.

The leaflets, varying from three fourths of an inch to one inch in length, and from one eighth to one tenth of an inch in breadth, where widest, are sharply elliptical at base, attached directly to the midrib, and taper with great regularity from the place of greatest width (about one fourth the whole length from the midrib) to their termination. The nervures are parallel, numerous, and so delicate as to be but obscurely traceable on most of the impressions.

The fossil to which this appears to bear most analogy, is the Zamites Whitbiensis of Sternberg ; but the leaflets of the Virginia plant are much smaller, more delicate, and of a narrower form, and the nervures much more minute.

ZABfTTES.

One of the most abundant of all the fossil relics found in the dark-colored slates a short distance above the coal, and sometimes in terlami Dated with the upper part of the seam, consists of long flat impressions, covered with straight parallel ribs or veins from thirty to forty to the inch. These impressions lie closely upon each other, between the parallel laminae of the slate, and appear to be of ex- treme thinness. The great distance to which the parallel ribs may be traced, without any indications of an articulation, and the close proximity of tbe impressions, would seem to exclude the supposition of their being compressed stems of a ealamite, while their narrow- ness and nearly uniform width, and some obscure appearances of attachment to a midrib, incline me to refer them to some very large Cyectdeous plant.

The above-described fossils comprise the more important, though not all of the vegetable remains which I have yet been able to procure in a state of sufficient preservation to be of much interest for pur- poses of comparison. Further explorations in which I am now en-

gaged will, it is hoped, add many new ones to the list, and enable me clearlj to determine the characters of a number of interesting, bat as yet obscure plants, of which I now have specimens.

Of animal remains, the only specimens thus far met with, are a single species oiith and the teetk of what was probably a Saurian, The former, which has been accarately described by Mr. Redfield, is referred by him to his new genus Catopteru$ under the title of Catoptertu maorurtu.* Its remains are met with profusely, though seldom in good preservation, in the black bituminous slates and lead- colored argillaceous sandstones, immediately upon, and for some distance above, the coal. In some localities the rhombic scales occur in immense numbers, blended with vegetable impressions, not only in these beds, but in the upper part of the coal itself. The teeth I have found both in the finer grits, and associated with the fish scales, immediately upon, and in, the coal.

Bee American Journal of Science, for 1841, vol. 41, page 27.

Contributions

To The

Geology Of Tue Tertiary Formations

Of Virginia.

CoNTBIBUnONS TO THE QeOLOOY OP THE TkRTIARY FOR- MATIONS OF Virginia, By W. B. Bogers and H.

D. Eogers.

Fbox TEAVSAonoHs or thb Axkeican PHiLOSoraioAL 8ooirr, Philadblpbia, 1885

And 1887.

Desgriftion of Some New Miocene Fossil Shells.*

TurriUlla terstriata.

Whorls strongly anprulated by three principal revolving elevated spiral ridges; the lowest, being about one-third from the base, is the most prominent ; the second, which clbsely adjoins and almost coalesces with the first, is much feebler ; the third, which is nearly one-third the height of the whorl from the summit, is more distiuct and is separated from the second by a deep and wide channel ; next the base of each whorl are three fine spiral stris ; others, to the nnmber of four or five, occapy the space between the principal ridge and the summit; crossing these are very fine indistinct transverse arcuated wrinkles.

This shell is obviously distinct from the variahilia in the great inequality of the three principal ridges, the depth of the central channel, and the greater delicacy of the transverse wrinkles.

Locality, vicinity of Williamsbarg ; in the Miocene shell marl. Length, about two inches.

Turritella quadri-striata.

Shell turreted, regularly conical ; whorls flattened, with four principal revolving equidistant spiral striss ; a fifth, less conspicuous, bounds the base of the whorl ; the whole of these are alternnted with five much smaller interposed striaa ; near the summit of the whorls are traces of others yet more delicate; five transverse ar- cuated wrinkles, not very distinct.

Locality, Williamsburg, as before ; length, one inch. This shell

These descriptions were published in connection with other contribu- tions to the Geology of the Tertiary Formations of Virynnia (1835, 1837, and 1839), which, being identical with certain pages of the Reports for 1885 and 1840, need not be repeated here. (See pagea 29 to 89, Report for 1835, and pages 419 to 487, Report for 1840.)-'£d.

differs from the variabilU in the flatness of the whorls, and the nnm- her and relative proportion of the principal strisB ; it is albo a ranch more delicate and smaller shell.

Natica perspeetiva.

Shell snhglohose, smooth ; suhstance of the shell rather thin ; nrohilicas open, with a rather prominent revolving rib, considerably above the middle of each volntion, terminating at the labrnm in a scarcely distinct callas ; spire somewhat elevated and acnte ; aper- ture semiciroolar, five-eighths the length of the shell. Length, eight- tenths of an inch.

Locality, Williamsbnrg. Miocene. This shell resembles some- what the }f. interna, but it is obviously different in being less de- pressed, and in the form and proportions of tlie aperture ; the general contour of the shell is also different.

Fissurella eatilliformu.

Shell nearly elliptical, slightly subovate, depressed, conic, with approximate very regular longitudinal costae, alternated with inter- vening striffi often very minute, the transverse concentric etrisB giving a very uniform granulation to the costea; foramen, oval, scarcely inclined; inner margin of aperture entire. Length, half an inch.

Locality, Shell-banks, Prince George county. Miocene. This shell has some resemblance in its inner surface to the cavity of a dish.

Area protraeta.

Shell rather thick, very oblong transversely ; ribs about forty, not very prominent, and hardly wider than the intercostal spaces, and longitudinally furrowed by three narrow grooves, the central one much the widest ; a very indistinct granulation on the ribs, aris- ing from the numerous minute transverse lines of growth crossing the longitudinal ridges of the ribs ; beaks prominent and distant, opposite a point less than one- third the length of the hinge margin from the posterior extremity; area wide, with numerous distinct undulated grooves, parallel to the hinge margin ; hinge margin rec- tilinear, with numerous minute straight teeth, those in the anterior half directed a little obliquely towards the anterior margin ; posterior margin rounded tilightly outwards, extending a little further back- ward than the angle ; anterior margin much elongated, extending in an oval curve far in advance of the end of the hinge; basal margin contracted opposite the middle of the hinge, and deeply crenate. Length, three and a half inches.

Locality, Shell-banks, Prince George county. Miocene.

Lfteina gpeeiosa.

Shell sub-elliptical, inequilateral, inflated, rather thin, with equal close-set rather elevated longitudinal ribs, and regular very close con-

centric striea ; Innnle small, yery distinct, and ovate-lanceolate; beaks small, pointed, and slightly prominent beyond the general curve of the margin, placed about one-third the transverse length of the shell from the anterior end ; cardinal teeth small, diverging ; lateral teeth equal, distinct, and nearly equidistant from the anterior cardinal ; hinge margin regularly arcuated, the rest of the margin, especially the posterior side, crenate within; posterior muscular impression elongated and slightly curved. Diameter, three-tenths; length, eleven-twentieths ; height, nine-twentieths of an inch.

This very beautiful shell occurs in nearly all the localities of the Miocene in the James river region.

VenuM cortinaria.

Shell sub-cordate, inflated, with very regular concentric, closely approximate, and very prominent imbricated ridges, which incline towards the beak, except the portion opposite the anterior, basal, and posterior margins, where they decline outwards towards the margin ; beaks moderately prominent, about twice as far from the anterior as the posterior end ; two anterior cardinal teeth, closely approximate above, second one of the left valve thick and snb-bifid ; lunule wide, cordate ; basal margin crenate within ; posterior mar- gin short, straight, and especially at the lunule finely crenate. Length, one inch ; height, nine-tenths of an inch.

Locality, Williamsburg. Miocene. This beautiful shell rarely shows the concentric ridges perfect, from their prominence and thin- ness.

Of the Place us the Geolooioal Series to which these Deposits

Belong.

That the strata here described, and the deposits identical and continuous with them, stretching extensively to the north and south into the aoining states, are referable to the Miocene period of the American Tertiary, will be readily admitted on adverting to the well- marked relations of their organic remains.

A careful summary of the fossils derived from the several locali- ties hitherto examined within The Peninsula, establishes the total number of those at present known to be very nearly one hundred. Of these not more than eighteen are ascertained to belong to species now living; showing a remarkable, though no doubt accidental cioiiir cidence with the average proportion of recent species found in de- posits of the Miocene period in Europe.

Lest it may seem objectionable to institute the comparison be- tween the recent and the extinct shells of several localities taken in the aggregate, the ratio has been examined as it exists in some of the localities separately. Thus in the cliffs at Eings Mill on the James river, the whole number of species whose imalogies are at present satisfactorily established, is about seventy-foar, of which but lourteen are of the present day, or recent. The per-centage here disclosed is therefore about nineteen, being nearly the same with

that above, and still almost identical with the proportions in several of the Miocene localities of Europe.

Making everjr possible aUowance for future discoveries bringing to light as recent, some of the now supposed extinct species, it is still difficult to imagine, with such a ratio as we have at present that the proportions can ever so far change as to make the living species of the deposit to equal or exceed the number of the extinct ; a con- dition necessary of course to entitle it to the name of Older Plio- cene, which it has received.

The circumstance that in Prince George county the Miocene is superimposed directly upon Eocene, from which it seems not to be separated by any features which would mark a long interval attended by abrupt or violent actions, furnishes another, though not a deci- sive argument against its belonging to a period so late as the Older Pliocene. It seems reasonable to infer, that the two would hardly be seen resting together in exact conform ability, as they do, had they been separated in time by the whole interval between the Eocene and the Older Pliocene, during which the surface of the former would be in a condition to undergo changes and irregularities no- where perceived where they are seen in contact.*

Of thb OniGiN of the DRPOsrr ovbblting the Miocene Shell

Mabl.

It is not easy, in the present state of our information, to ap- proximate to the precise era when this overlying deposit was pro-

In a recent publication (Silliman's Journal, vol, 28, p. 106), Mr. Conrad has attributed to a portion of the formation hero under diAcuasion, namely, the localities of Yorktbwn and the James river, near Smithfleld, a date still more recent than the period of the Older Pliocene. He ranks those deposits, to- Bcther with another at Suffolk, Viripnia, and one on the St. Mary's river, Mary- uuid, under a new division, Medial Pliocene; it is stated at the same time that the recent species at those places compose about thirty per cent. A subdivis- ion of the formation as it occurs in Mainland, characterized by Pema maxil- lata and a less proportion of recent species, is referred to the Older Pliocene, while the opinion is advanced that the Miocene is probably altogether want- ing. Now to those familiar with the principles or the new nomenclature of the Tertiary, it is obvious that the beds, so styled, the Older as well as the Medial Pliocene, are entitled, in strictness, to the appellation of Miocene only.

To confer on a formation the name Medial Pliocene, its shells should con- tmn about thirty per cent extinct, and seventy per cent recent, and not the oon verM. We believe, moreover, that the per-ccntage of recent species at Yorktown is even materially less than thirty.

In No. 8, of his work on American tertiary shells, issued a little earlier than the other article Mr. Conrad adopts a somewhat different classification, calling the several locahties in Virginia and Maryland, Older Pliocene, as before, ex- cept that stratum low down in the Maryland formation which is distinguished by the Pema maxillata, and this he denominates Miocene. For reasons before stated, namely, the small per-centagc of recent species throughout them all we believe the whole together to have been produced in the Miocene epoch, and to belong to one formation j and we have been led into this note in the sincere wish to settle the question of the age of this division of our Atlantic Tertiary formations, lest the student of American geolo be difheartened by the pexplezlty which grows out of a shifting and inconsistent nomenclature.

duced, though it appears to have had a date perhaps long anterior to the latest snperncial dilavium with which it is often confounded. We infer this from the verj general ahsence of all those signs which mark a transportation violent causes from a distance, its mate- rials heing finelj comminuted clays and sands usaally arranged in a manner denoting a somewhat quiet deposition. On the other hand, its containing no fossils, its distinct separation from the fossilifer- Otts marl stratum heneath it, the snr£EUie of which is farrowed and deeply channelled, as if an interval of erosive action had preceded it, are facts which may possibly displace it from the Miocene era altogether, and which, for the present at least, throw entire uncer- tainty upon the inquiry as to the position which it should occupy in the Tertiary series.

It is not unlikely, all things considered, that the origin of this deposit is to be traced in the rise from beneath the sea of some of the more western portions of the tide water plain ; in other words, with the appearance above water of the Eocene tract in that quar- ter. This is rendered probable from the circumstance that this superficial bed often abounds near the bottom with grains of the green sand mineral so abundant in the Eocene of Virginia. It is corroborated, likewise, by the fact that the shelly Miocene stratum reposing upon the Eocene, sometimes Rhows tokens of considerable violence over its surface, the shells being, throughout a depth of several feet near the top, in a fragmentary state, and much dis- turbed, as may be seen in Prince George county, and on the Ghick- ahominy river.

If we conceive that tracts in the Eocene district, or above it, were upheaved to near the waters level, or entirely out of it, while tue country to the east was still submerged, we may not only explain the facts here mentioned, but by adverting to the nature of the actions which would supervene, we may account, by the sudden draining off of the uplifted water, for the eroded surface of the Miocene marl, and the sudden and total extinction of animal life which took place. To this would naturally succeed the introduction of nearly the same kind of matter under more tranquil circumstances, brought down from the newly exposed tract by river action, the probable source, we may conjecture, of some of the sands and clays of finer texture which occur so regu- larly and quietly stratafied every where in the upper parts of the dei>osit.

Later than all these operations must have been the diluvial ac- tion, more or less extensive, which grooved the surface of this de- posit throughout the Tertiary region with its innumerable ravines and shallow valleys of excavation. Whether this last change was impressed upon the surface by the final emergence of the whole ter- ritory from the sea to its present level, or by some more universal denuding fiood which has swept the continent generally, we venture not to decide ; though the comparatively small amount of trans- ported superficial pebbles and boulders, and the absence of any which can be traced beyond the nearest rocks at the head of tide,

inoline qb to attribate the denudation in question to the supposed heal action rather than to the other.

Eocene Fobmatio of Viroixia.

Though some attention has been devoted by Mr. Conrad, and other American naturalists, to the Tertiary fossils of several locali- ties in Virginia, as yet their researches have been limited to such as appertain to the subordinate divisions of the Tertiary group, arranged by Mr. Lyell under the head of Pliocene and Miocene ; and though the existence of an Eocene deposit might naturally have been inferred, no locality of this character appears to have been known to them. The existence of an extensive Eocene formation in East- em Virginia is now for the first time announced, as furnishing an interesting step in the progress of the geological inquiries which are now on foot by legislative authority in that state.

This formation appears to have a general meridional direction, traversing the state from the Potomac to the Roanoke. It is inter- sected and exposed by the principal rivers, first making its appear- ance at from twenty to thirty miles below the primary ridge. The most interesting locality which has as yet been visited, and that from which the fossils have been most abundantly obtaine<l, is on the James river, beginning a little above City Point, and extending nearly in a continuous manner to Coggins Point, a distance, follow- ing the flexures of the shore, of about eleven miles. At Coggins Point, Torbay and Evergreen, the cliffs have a height varying from thirty to forty feet. At the base, a stratum of what appears at first to be a blackish clay extends nearly horizontally throughout the whole distance, rising a little as it ascends the river. Its height above the water at Coggins Point is about three feet, at Evergreen upwards of ten, measured to the upper edge of the stratum. It con- tinues downwards to a depth of six or eight feet, and terminates in an argillaceous clay of a bluish-gray colour. This dark stratum consists largely of particles of green sand, or silicate of iron and potash. It contains a great number of Eocene fossils, among which are Cardita planicosta, Fusus longmvis, &c., &c., already known as existing either in the Eocene of Paris or Alabama, or in both. But besides these it also contains a variety of beautiful and new species, some of which will be described in the present paper. These shells are, at some points, almost entirely dissolved, and very perfect casts alone can be procured ; but at other points, though in a soft con- dition, they can, by using great care, be obtained in an entire state.

Above this stratum is a layer of what Mr. Edmund Rnffin, the able editor of the Farmers' Register of Virnia, calls gypseous earth. This stratum appears once to have abounded in fossils, but at pres- ent only casts, and those in a very soft condition, can be found. They are, however, identical with the fossils of the lower stratum. The earth of this layer, besides a considerable proportion of green sand, contains a large amount of sulphate of lime, disseminated in mi- nute grains and grouped in laie and massive crystals. Immediate

above oconrs a thin stratum of white clay, at the junction of which with the former layer the crystallized gypsum is found in great abundance, and almost perfectly pure. Above the clay is a stratum of shells in a very disintegrated condition, but consisting of Ostrea sellffiformis and other Eocene fossils, and immediately above is a stratum of the shells of our middle Tertiary. A few scattered peb- bles of a brown hue, hardly numerous enough to form a stratum, separate these two very distinct formations. In this uppermost layer are found the common Pecten and Pectunculus of our middle Tertiary.* The whole thickness of the Eocene deposit at this point appears to be about twenty feet. At distant points, where this de- posit has been examined, as for instance near the Piping Tree, on the Pamunkey, and near Port Royal, on the Rappahannock, as well as upon the Potomac, much the same arrangement and succession of strata have been remarked.

The section at Coggins Point presents the interesting feature of a juxtaposition in the same cliff, of the Eocene and newer Tertiary formations, and on this account must be regarded as an important locality.

The fact too that in this as well as other places where the Eocene deposit has been discovered, so very large a proportion of the chlo- ritic sand is contained in the matter embedding the fossils, is, we pre- sume, an unexpected and interesting circumstance. Even the New Jersey secondary strata are seldom more abundant in this pecaliar mineral product than the formation referred to, and hence the farmers of Virginia are beginning to apply this material to their fields.

Nkw Fossil Shells of the Eooene of Virginia.

Nueula cuUelliformis.

Shell ovate, ensiform, somewhat inflated, rounded before, much elongated, and tapering behind, the posterior length more than twice the anterior, furnished with very fine, hardly distinct concen- tric striro, and one distinct and one very obscure rib behind ; anterior part with an indistinct fold ; shell thin ; lunule long and lanceolate ; beak small ; anterior series of the teeth gently arched ; posterior series straight ; teeth in both acutely bent, the angles directed to- wards the beak ; margin entire ; cavity of shell shallow, with a ridge passing from the beak to the posterior margin. Transverse length, twenty-eight hundredths; height, eight hundredths of an inch.

♦ Among the interesting fossils of the middle Tertiary above, is an enor- mous specimen of Aatrea, whicli is worthy of being described. This mass was some years disengad fVom the upper part of the oliff at Torbar, and its now lying on the shore, firmly fixed in the sand and olay. Tboufh it has been much reduced in size since its fall, it is still of immense magnitude. Its form is of course very irregular, but its largest diameter mav be estimated at four and a half feet ; and its weight is probably seven or eight nundred pounds. On the shore are likewise found vast numbers of the teeth of sharks, some of them of enormous dimensions.

Locality, Goggins Pointy Prince George comity, in the green sand stratum. This very delicate shell approaches nearest to the N. media of Lea, the jEqualis of Oonrad, but differs in the great elongation of the posterior end, in the ribs, and in the less distinctness of the transverse strisa.

Nueula parva.

Shell ovate, inflated, rounded before, not much produced, but rapidly tapering to a truncated point behind, furnished with about twelve rather coarse concentric folds or ridges, and a longitudinal gently depressed groove or undulation of surface, running from near the beak to the posterior basal margin ; beaks nearly central ; ante- rior series of teeth slightly arched; posterior series nearly straight; margin entire; cavity rather deep. Length, three-twentieths; height, two- twentieths of an inch.

Locality, same as tlie preceding.

Ostrea $inuo§a.

Shell sub-orbicular, or equilaterally sub-triangular; inferior valve moderately convex, with the laminaa of growth profoundly plicated into loops, which are imbricated so as to produce regularlr radiating ribs; hinge-plane depressed, and in a line with the dorsal margin, which is long and straight, the sides of the inferior valve being di- lated into the form of ears ; fosset placed symmetrically and cen- trally in the hinge, and less than one- third its length, and curving suddenly at its termination in a narrow groove; beak slightly curved to the right and truncate ; muscular impression small ; inferior valve very slightly convex or flat, nearly circular, with concentric almost circular wrinkles. Length of the specimen four and a half inches; diameter between the ears five and a half inches ; diameter of flat valve four inches.

Locality, Evergreen, James river, in the lower or green sand stratum of the Eocene This very beautiful fossil oyster will be seen to differ from the 0. campreasirostra in several essential par- ticulars, especially in the structure of the hinge, in the more sym- metrical and profound plications on the inferior valve, in its less convexity, and in its more regular dilatation on the upper margin into partial ears.

Cytherea ovata.

Shell subovatc, somewhat inflated, with concentric transverse striae, very fine near the umbones, but much coarser near the mar- gin ; beaks rather elevated ; lunule very indistinct ; teeth elevated and straight, the two posterior ones of the left valve small, much compressed, approximate, and nearly parallel; the anterior tooth large and grooved by a deep canal; cavity of shell deep; margin entire ; posterior margin straight, and separated from the muscular impression by a fold or groove. Length, one and one-tenth of an inch ; height eighty-five hundredths of an inch.

Locality, Coggins Point, in the Eocene green sand.

Dbscbiptiok of SsrsBAi. Spboiss of MrooBNB AND EooEiTB Shklls,

Not Bbfobb Dbsoribbd.

Turritella fluxionalU.

Speeific cMracter. — Shell elongated, turreted, whorls aboat twelve, slightly convex, subcarinated at base, longitudinally striated with five principal hardly granulated revolving stri, the lowest being doable ; between these are very fine ones, most nnmerons towards the base of the whorl. Very obtuse nearly obsolete transverse strias give to the principal longitudinal stria a sub-granulated undulation. Aperture sub-quadrangular. Length, one inch and two-tenths.

Locality, Williamsburg and the neighbourhood, in the Miocene of eastern Virginia.

Description, — This delicately striated shell has two of its finer class of lines separatingthe twostronger threads of the first, or carinal stria, about six of them between this and the second, about five between the second and third, either two or three between the third and fourth, one between the fourth and fifth, and from the fifth or uppermost to the top of the whorl about two more occur. It is the most convex in its whorls of all our Miocene Tvrritellm if we except the 71 i>aria- hilis, and from this it may readily be distinguished by the greater number, delicacy and remoteness of its principal longitudinal strisd.

Cytherea lentieularis, Plate III., fig. 1.

Specific charcboter, — Shell large, depressed, discoidal, rather thick, length nearly jequal to the breadth; transversely striated; lunule long, ovate, obscurely defined by a very faint impressed line ; um- bones rather depressed ; beaks small, hardly recurved ; teeth straight, divergent ; cavity of the shell not deep ; margin entire. Diameter about two inches.

Locality, eastern Virginia, in the Eocene, where it is a common species.

RernarJcs. — From the extreme friability of this shell it has been impossible, hitherto, to procure a perfect specimen. It differs from all the CytherecB of our American Eocene beds in its nearly orbicu- lar form, and in its slight degree of infiation. The insulated tooth of the right valve is long, straight, and not much elevated. The anterior cardinal tooth in the same valve is slightly bifid. The striso upon the surface of the disc are almost obsolete, where decay has not removed the external laminsQ. The small incurvation in the beaks distinguishes it from C, Poulsonii of Conrad {0. ghhosa Lea), to which species it bears some resemblance.

Cucullea onochela,* Plate III., fig. 2.

Specific cha/tcbcter, — Shell ovate, subtrigonal, subcordate, oblique, the anterior margin nearly straight, inequUateral, inequivalve, thick,

♦ From its resemblance to an asR's hoof. This sholl in my Rnocimen has an obscure ride croasing the cardinal area from beak to beak. ($ee specimen from Potomac

ponderous, globose; longitadinal co8t nnmeroiu, depressed and flat, apon the left valve obsolete; trails verse striee minate, obscnre, except near the inferior margin ; hinge line very straight ; umbones not very prominent; beaks small, slightly incarved, and not distant. Length equal to the breadth, three inches.

Locality, western part of the peninsula of the Potomac and Rap- pahannock, Virginia, in the Eocene.

Deaeriptum. — Alternate longitudinal striffi, very obscure and delicate, divide many of the costes along the centre, and throw them, especially next the anterior side, into pairs. The beak has four-sevenths of the length of the hinge on its posterior side. This species may be known from the C, incerta of Deshayes by its much greater size, its less quadrangular form, by the greater number of its lateral teeth, and the less incarvation of its beaks. It is not less readily distinguished from 0. giffontect a species previuling in the same beds with it, by its less width, compared to its height, by the less obliquity and greater length of its posterior margin, by the beaks being less remote and less incnrved, and by the shell being smaller, but materially thicker, and more inflated near the base. A prominent feature is the great inflation of the valves, especially to- wards their base. The hinge is well marked by from four to five lateral teeth, next the posterior side, and from three to four next the anterior, all being slightly curved, striated by deep irregular grooves on their sides, and of nearly equal obliquity. The central longitudinal teeth are numerous, irregular, and slightly oblique. The area of the ligament is nearly a segment of a circle, the straight hinge line being the chord ; its surface is marked by about six deep, rather waved grooves. The right valve is the largest, overlapping the left on the lower margin, which is moderately crennlated in both. In the cabinet of the Academy of Natural Sciences of Phila- delphia there are, besides three large casts of C, giganUa two ap- parently of the present species, somewhat larger than the shell now described. These latter, I have satisfied myself, belong to Cpno- chela as an internal cast of this made in wax is precisely like them, though very different from the casts of G, gigantea.

Cucullea trajiscersa, Plate lY., fig. 1.

Specific character. — Shell subovate, subtrapeziform, oblong, ob- lique, inequilateral, inequivalve ; longitudinal strisB numerous and delicate, the alternate ones nearly obsolete, dividing the costs into pairs ; transverse striss very minute ; hinge straight, area of ligament narrow, with from three to four furrows; beaks small, somewhat incurv, and not distant. Length four-fifths of the breadth, but these proportions variable.

Locality, King George county, Virginia, in the Eocene, near the Potomac river.

Description. — The division of the cost® into pairs, the great ob- liquity of the posterior margin, and its great breadth, are among the characteristics of this shell. The area of the ligament rises from

the hinge at a more obtase angle next the anterior side than at the posterior, so that it corves upon an axis not coincident with the hinge line. The transverse lateral teeth are very slightly oblique, they are on the anterior side three, and on the posterior four ; fine acute grooves or strira mark both sides of these teeth. The central longitudinal teeth are few, irregular and rather oblique. The ante- rior and inferior margins of the right valve, especially, are strongly crenulated on the inner edge. The anterior muscular impression is Bubtriangular and depressed, the posterior one is nearly rectangular, the inner angle being a little elevated. 8hell moderately thick.

Venerieardia aseia. Plate IV., flg. 2.

Specific character. — Shell subovate, subcordate, not thick; costfB much depressed except on the beak ; about thirty ; transverse strisB numerous from the margin to the umbones, nearly obliterating some of the longitudinal sulci; lunule profound, subcordate, triangular and equilateral; anterior muscular impression rather remote from the hinge; cardinal teeth arcuated, oblique; inferior and posterior margins crenulated. Length, three inches two- tenths ; breadth, three inches six-tenths.

Locality, King George county, Virginia, near the Potomac, in the Eocene.

Remarks, — This shell can be confounded only with the V. plani- eosta, to which it is possible we ought to refer it as a variety. They are readily distinguished, however, by the greater length and curva- ture of the whole anterior margin, especially the portion along the ligament ; the hinge is broader and longer, and the teeth are less prominent and more arcuated ; the muscular impression, on the an* terior side, is further from the hinge ; and the whole valve is wider, flatter and thinner. These differences, with the flatness of the costsB, appear to warrant us in regarding this shell as a distinct species from Venerieardia plani408ta. That shell also is found in the Eocene of Virginia, but usually not in the same bed with V, aseia,

Cardium quadrans, Plate V., fig. 1.

Spedfie character, — Shell subtrapeziform, oblique, inequilateral, posteriorly much expanded, compressed anteriorly ; thin and fragile ; longitudinally ribbed, costas about thirty-five, broad, depressed, and slightly convex ; transverse striaj somewhat coarse or squamose near the margin. Umbones small, beaks incurved, lunule long ; posterior cardinal tooth small, and of nearly uniform breadth, posterior lat- eral tooth large: margin crenulated by distinct but not deep undu- lations. Length, three inches seven-tenths; breadth, two inches eight-tenths.

Locality, eastern Virginia, Miocene.

Iiemarks,—OwmQ to the extremely friable state in which this fossil is found, and to its being associated with C, magnnm and C. laqneatttm, its fragments have passed for these species; but its tra- pezoidal form, and the great width and depression of the longitudi-

mil costffi, show a strong contrast to the laqfieatum while, in addition, its less size and less inflation prove it different from the nuignum.

The great expansion of the posterior slope into an almost an- ricnlated margin, is highly distinctive of it as a new species.

Crasaatella capri-cranium. Plate V., fig. 2.

Speeifie charaeter, — Shell ovate, oblong, compressed, sab-rostrate, rather thin, witli coarse, obtnse, transverse wrinkles, and fine trans- verse strisB ; a prominent sinus extends from the beak to the an- terior termination of the inferior margin ; truncated anteriorly, at a right angle to the base ; margin slightly concave at the lunnle, which is deep, wide and ovate ; inferior margin delicately crenu- lated within. Length, one inch four-tenths; breadth, two inches two-tenths.

Locality, peninsula, between the Potomac and Rappahannock rivers, in Yirgiuia, in the Eocene.

Remarhs, — This species may readily be distinguished from the melina, which it somewhat resembles, by its less thickness, and by the crenolation on its inner margin, but especially by its differ- ent outline being much more contracted on its anterior side.

Fa$eiolaria rhomboidea. Place Y., fig. 8.

Specific eharaeter, — Shell tnrreted, fusiform, and nearly smooth, greatest dilatation about the middle, spire conical, whorls convex, with longitudinal, obsolete or interrupted strife, the lower seven or eight upon the body whorl, and those upon the upper whorls, be- ing distinct and slightly undulated. On the body whorl are ten or eleven very faint, brown, narrow, longitudinal lines, three of which are traceable upon the spire. Transverse stria?, distinct, moderately distant, and arcuated. Aperture a little less than two-thirds the length of the sliell, columella arcuated, plicated with three very oblique folds, the middle one the most elevated, labium delicately striated within the edge, beak slightly recurved. Length, two inches four-tenths; breadth, one inch two-tenths.

Locality, Surry county, Virginia, Miocene.

Description, — This is a thin shell, though not difficult to procure entire. From the F, mvtabilis, the only other species of our Tertiary, it will readily be known by the greater length and arcuation of its beak, by its less regularly fusiform outline, and by the difference in the number of its whorls, and of the plications on the columella. The high preservation of the specimen from which the description has been taken, permits us to trace upon its whorls its longitudinal coloured bands, affording a very interesting specific character.

-i

'I

Descbiption of the Plates.

Plats I.

Fignre 1. Turritella terstriata. Figure 2. Turritella quadri-atriata. Figure 8. Natiea pertpeetita. Figure 4. Fiasurella eatUl{farmig Figure 6. Area protracta. Figure 6. Lucina apeeuMa. Figure 7. Venus cartinaria,

Plate II.

Figure 1. (htrea nnuoea. Figure 2. Cytherea atata.

Plate III.

Figure 1. Cytherea lentieularii. Figure 2. CueuUea anoehela.

Plate IV.

Figure 1. CueuUea tranwena. Figure 2. Venerieardia aeeia,

Plate V.

Figure 1. Cardvum quadrane. Figure 2. Craseatelta eapri-eranium Figure 8. Faeeiolaria rhamboidea.

Observations On The Natural Coke

or THE

Oolite Coal Region In The Vicinity Of Richmond

Obsebvations on the Natural Coke and the associ- ated IGNEOUS AND ALTEBED KoOKS OF THE OoLITE

Coal Kegion in the vicinity of Kichmond, Vir- ginia.

Fftox Fboocsdinos or thb Boston Socutt or Natubal Hintwr, 18Slr-*66, Vol. Y.

In the district on tbo north side of the James river, where the most valuable seam of coke has been explored, it is at present wrought by two vertical shafts. In that nearest the outcrop, the coke is reached at 112 feet from the surface ; in the other at 207 feet, the dip of the coal measures being nearly west, and at a low angle. A third shaft, recently wrought, which lies nearer the mar- gin of the basin than either of the preceding, cuts the stratum of coke at the depth of 90 feet. A bed of whinstone, or coarse gray trap, is intercalated in the coal measures of this part of the basin, intersecting the two first mentioned shafts, but cropping out a little west of the third. This bed is met with in the deepest and most western of the shafts, at a distance of about 100 feet from the sur- face, and is more than 80 feet thick where it is cut through ; but in the next shaft it is struck at a depth of less than 80 feet, and has thinned down to about half the preceding thickness.

One of the most remarkable effects produced by this igneous bed is seen in the stratum of carbonaceous fire-clay which lies next beneath. This, which in the second shaft has a thickness of eleven feet, has been greatly indurated, and made to assume a columnar structure, by which the whole mass is converted into a congeries of closely packed five and six sided prisms, often quite regular, usually about half an inch in diameter, and always at right angles to the lower surface of the trap. A portion of this bed, originally occu- pied by impure coaly matter, presents the same columnar structure, but the material is a compact plumbaginous coke, with much earthy matter intermixed. The general aspect of the gray part of this bed strongly resembles that of the coarser varieties of fire-brick after they have been long exposed to intense heat. This is what might be expected, for in the bed in question we have the very materials of fire-brick, and in the overlying trap we have a source of igneous action which, in the originally molten condition of this substance, could not fail to work great changes in the contiguous strata. This

colnmnar indarated clay, or natoral fire-brick, when recently broken, emits a most offensive odor, partly that of snlphoretted hydrogen, and partly, perhapi, caused by a snlphnret of carbon.

At the depth of about seventy feet below the bottom of the trap occurs the bed of natural coke, for the mining of which chiefly these openings have been made. This interval below the fire-clay is occupied by bluish and drab argillaceous and sandy slates, with some worn sandstone, the former abounding in impressions of plants, among which may be noted Enisetum columnare, Zamitcs obtusifolius, and Tieniopteris magnifoha — forms which, many years ago, I pointed out as marking the Oolite age of these coid-bearing strata. The baking action of the trap is curiously shown in all these fossils. The coaly matter of the stems and fronds when closely examined is seen to be blebby or blistered. It is in fact coke, which, while it retains the outlines and stronger markings of the plant, has in its partial fusion obliterated all the finer characteni of the organized surface.

The coke, where it has been successfully mined, forms a bed about five feet thick, including but little ate, and presenting a nearly homogeneous mass of a bluiah-black color, uniformly vesicu- lar, and light enough to float in water. It retains only a minute fraction of the volatile ingredients of the unaltered bituminous coal of this region, but it ignites readily, and burns like the oompacter kinds of ordinary coke. Throughout the bed, but especially towards the top, it presents a partially colnmnar structure. Where this structure is marked, the coke is found to crepitate when heated. In some localities on the south side of the James river, where the whole mass of coal and adjoining thale has been rendered complete- ly colnmnar, the material, in the process of heating, breaks up with explosions like the crack of a pistol, at the same time projecting its fragments to some distance from the grate.

The gradnidly diminishing influence of the trap bed as we recede downwards, is illustrated by the section in one of the shafts which embraces a thickness of fifty feet of strata below the seam of coke above described. After passing through indurated fire-clay, lying immediately beneath the coke, we have a thickness of about twenty feet of slates, followed by a thin seam of semi-coke, or ooky coal — more bituminous below than at the top ; and after this, descending through some twenty feet more slates and sandstones, we come upon a bed of bituminous coal, which appears to have sustained no alteration beyond the development throughout the mass of a colum- nar structure. In the deepest of the three shafts, the seam now wrought, under the intelligent direction of Oolonel Worth, corre- spond to the coky coal above described, the lower layer retaining much of its original bitumen. In all these workings, the gradation of metamorphio infiuence is beautifully marked within a distance of less than fifty feet of strata, from the greatly altered shale or fire- clay, immediately beneath the trap, through the successive slates and coke seams, to the unchanged bituminous coal at the bottom of the section.

Repoet

Oh Tbi

Pridevale Coal And Iron Ore,

West Virginia.

Eepokt.

To the President and Directors of the Pridetale Iron Co,

Gkntlembit : The following report of the mining resooroes of the Pridevale Iron Company, will be found more detailed and spe- cific than was contemplated, when the geological examination of the property was first proposed. This has arisen from the variety and minnteness of the olraervationB which I have found it necessary to make. Ilad I met with a seam of Ore of the great thickness and ex- tent which mmor so often vagnely ascribes to these deposits, I could in a short time, have made all the examinations necessary, to assure the Company of a solid foundation for enterprise, and to guide in the mining operations which would be required. But in the Pridevale tract, as in the coal regions of Virginia and Pennsylvania generally, the seams of Iron Ore are not large, and are fluotnating. I have therefore, felt it to be vital to the interests of the Company, that I should examine every layer of Ore on or near the Companys land, in order to learn, in the first place, whether from these multiplied sources, notwithstanding the absence of any large deposit, an ade- quate supply of Ore could be anticipated ; and, in the second place, by a comparison of their character, thickness and continuity, to form a saie judgment as to which beds are the most desirable for use, and the most to be relied on for permanency.

With these views I have visited every opening of importance within the limits of the property, as well as many in the neighbor- hood, and I have included in my examinations the Coal seams, and beds of Fire-clay and Limestone of each locality. The result of this extensive exploration, has been the conviction that the Anna, Henry Clay and Woodgrove furnaces, can each command an adequate sup- ply of Ores of various composition and richness, and that by a judicious mining of the better varieties, the products of the Furnace and Rolling-mill may be impressed with the best qualities which the several uses of the metal aemand.

As a knowledge of the geological place in the associated rocks, of the several layers of Iron Ore, Coal, or Limestone, is essential to the successful tracing of their outcrop, and therefore to the de- termination of their continuity, and the area which they cover, I have made it an object of prominent importance to ascertain the

sQccession, and, as nearly as time and means vroold permit, to meas- ure the thickness of each band of Sandstone, Slate, Shale, or Lime- stone, included in the tract, and to locate in their proper places the lajers of Ore and beds of Coal and Fire-clay.

The results I have embodied in a graphical form, in two Oeolo eal Sections representing the several beds of rock, and their included valuable deposits.

Section A is intended simply to show the succession and relative thickness of the several strata, from the great Limestone beneath the Goal-Measures, up to the Sandstone which lies over the Big Coal. This, I believe, includes all the important bands of Rock, Ore, Coal, Fire-clay and Limestone, within the limits of the Pride- vale tract. In this section, the strata are represented as lying layer upon layer, in horizontal beds, so as together to form a vertical column. In reality, however, such is not their position. "While they maintain the order of succession exhibited in this vertical sec- tion, or geological eolumit, they are placed in positions more or less inclined having, with a few exceptions, on the Pridevale tract, a descending slope or dip towards the northwest.

Section B is designed to represent the altitudes, as well as the dimensions and order of the strata. It indicates the general con- tour of the land on the north side of the Cheat River, and includes the geological structure of the tract, extending from the centre of Laurel Hill to the hill containing the Big Coal at the western limit of the Companys property. In this section will be found indicated the place at which the several bands or seams of Ore and Coal come to the surface, or crop out and the points where, in virtue of their sloping position, they are made to dip beneath the level of the river. For the sake of clearness, and to avoid the inconvenience of great length, a less scale has been used for the horizontal than for the vertical measures. This has the effect of steepening the dips, and thus ving the desired prominence to the structural features of the section.

It should be understood that neither of these SeetioM claims to be minutely accurate or complete. A much longer time, with all the resources of a topographical survey, would be requisite to furnish the materials for a really exact picture of the economical geology of this region. The want of even an appropriate topographical map has added greatly to the labor of compiling in the field the repre- sentations here given of its geology. But it will, I think, be found, that a great practical object has been secured in determining the order of succession of the strata and their valuable contents, in trac- ing many of them along their outcrop, and in measuring their thicknesses and distances asunder.

It must be remembered, that the sections have been constructed with reference to the formations as they present themselves on or near the Cheat River above and below the Anna Furnace — and will not, in all their details, be found applicable to the vicinity of the Woodgrove Furnace. Even in this short interval, some of the sub- ordinate divisions of the Coal-Measures undei*go important changes

of oompositioii and thickness; and these alterations affect also the Goal, Iron Ore and other materials associated with them.

Hereafter, should a more thoroogh and detailed sorveT of the whole tract be undertaken, I would recommend, as of much practi- cal value, a vertical and a transverse geological section for this vicinity; but, meanwhile, some of the more important chunges which present themselves at Woodgrove will be found noted in the body of this Report.

In presenting the result of my observations, it will be conven- ient, as well as useful, to classify them under the following heads : —

Of the General Geological Structure of the District.

Of the several Groups of Ore Beds.

General Remarks on the Ores.

Of the Ooal-Seams.

Of the Limestones.

Of the Fire-Olays.

Of ths Gektebal Geoloot ot tbb Distbiot.

The Laurel Hill range, upon and along the western flank of which the company's land h situated, is a broad, moderately elevated mountain, prolonged from Pennsylvania, in a 8. W. direction, for some thirty miles into Virginia, and forming the last conspicuous swell in the area of the cofld-bearing rocks. The strata comprising this mountain present what is called an antielinal structure — that is. they come downwards from its centre towards the opposite sides of the ridge, and form, when unbroken, a conUnnous arch, tiie flat crown of which corresponds to the centre of the mountiun. This is clearly seen in Section B. The inclination or dip of the strata, on the northwest side of the mountain, is towards the northwest; that on the opposite side, towards the southeast. This structure is clearly revealed, in the grand gorge, or winding transverse val- ley, by which the Cheat River passes through the Laurel Hill.

Here, about midway between the opposite flanks of the range, are seen the peculiar sandstones and slates of a formation geological- ly far below the true Coal Measures, but which sometimes includes a thin and delusive coal seam. These rocks form the upper part of the Veipertine series of Virginia and Pennsylvania geology. In a broad arch, externally concentric with this, is the group of reddish and buff sandstimes and soft red shales, associated with a thick mass of limestone, and terminated above by dark shales, including several valuable layers of Iron Ore. This is the Umbral series of the Virginia and Pennsylvania geology. The limestone and other hard rocks of this group form, on the sides of the reat water-gap of the Cheat River, a line of cliffs in a long arch, high in the face of the hill, but still far below the true mountain summit. Next above, and exterior to this arch of umbral limestone, and overlying red and iron-bearing shales, is the lowest division of the true Coal-Measures — the Serai series of the Pennsylvania and Virginia geology. This is tJie great Serdl Conglomerate or the Millstone-grit of geologists. It is a

ooane and often pebbly grey sandstone, in massive beds ; and wben not removed by denudation, is seen crowning the mountain with lofty mand cliffs, soch as the Raven rocks, the remnants of a con- tinuons mass, which once bent over the mountain in a grand, nnbroken arch. Fortunately for the iron manufacturer, this thick cover of rock has been swept away, over large depressed areas on the top and brow of the mountain, and access has thus been given to the Iron Ores, imbedded in the next subjacent strata.

Above the great conglomerate, the series of strata embraces sandstones, often conglomeritic, slates, shales and limestones, with beds of Coal and Fire-clay, and layers of Iron Ore, all included under the general title of Goal-Measures or the SereU roeh$ of the Virginia and Pennsylvania geology. The general dip of these strata on the western slope of Laurel Hill, is towards the northwest, but becomes more nearly horizontal, and even takes a very feeble oppo- site dip, as we recede in that direction. This flattening and some- times slight reversal of the dip, as indicated in Section B, has evi- dently the effect of maintaining the limestones of the Quarry Hill high in their extension westward into the hill of the Big Coal, and to give that seam a greater elevation above the river, than with an undiroinidhed western dip it would have maintained.

The Goal Measures included In the Pridevale property, consist of the Older Goal group, the Older Barren shales, and the lower part of Newer Goal group. The Older coal group extends from the top of the great Gonglomerate or Gliff rock, to the top of the lesser cliff, which lies above the Four-feet vein of Goal. Within this interval, generally, two or more workable seams of coal are included. The Older Barren shales occupy the interval between the top of the less- er Cliff rock above mentioned, and the Big or Seven-feet Coal. This group is chiefly composed of red or variegated shales, calcareous sandstones and ochreous limestones, and usually contains very little available coal.

The Kewer Goal group contains, at its lower limit, the Biff Coal, over which, as at Eclipse Rock, is usually a heavy mass of sandstone, and still higher in the series, two or three workable seams of coaL But these are geologically too high to be contained in even the lofti- est hills on the Pridevale side of the Monongaliela, and are met with for the flrst time on the high grounds some distance west of that stream.

Of Thb Iron Oses.

For the sake of greater clearness of description, and as a guide for future explorations, I think it expedient to group the several Ore-beds thus far discovered, according to certain geological bound- aries, which are, for the most part, sufficiently marked to be easily determined. It must be borne in mind, however, that this group- ing does not necessarily imply any special agreement in composition or richness of the ores so associated, although in some of the groups such a resemblance actually exists.

TTie Ut or Martin Group of Ores.

The Firit or lotoeit group of Ores of which the Martin Ore may be taken as the type, is embraced in a mass of black, buff and brown- mh. shales, and greenish shaly sandstones, lying beneath the con- glomerate, and having an aggregate thickness, varying from forty to tifty feet. This mass is separated from the conglomerate proper by some twenty or thirty feet of a rather fine-grained and tough sand- stone, of a buff color, which is usually exposed at the base of the great cliffl

The Ores of this group are, of course, accessible where the moan- tain is traversed by the river ; but, in this position, are in general deeply covered and obscured by the accumulation of fragments of the conglomerate which have fallen from the cliff. They are, how- ever, laid bare extensively on the high grounds near the centre of the Laurel Hill range, where, by great denuding action, the arching cover of the conglomerate has been swept off. Such are the con- ditions under which they have been found at the head waters of Quarry Run and its branches, and of Middle Run — the former flow- ing by the Henry Clay, and the latter by the Woodgrove Furnaces. Beginning with the lowest band or bed of Ore included in the group, I shall travel upwards, describing each in succession, as regnrds chemical character, geological position and other particulars bearing on its economical value, as far as these have been ascertained.

The Fint or lowest Ore of the Martin group, is that called by the miners the Red-belt Ore, This lies a few feet above the first de- posit of red shale met with in this region, under the great con- glomerate, and is hence very easily traced and identified. It has been mined along the outcrop quite extensively by benching in the immediate vicinity of the Henry Clay Furnace. It is here chiefly a Hematite and is of fair quality, probably a forty per cent, ore when se]eote<l. In the benches no opportunity was presented for estimat- ing the thickness of the bed. About a quarter of a mile below the Furnace at the Meeting-house, it has been drifted on by Carr, who states its thickness at eighteen inches; but the drift having fallen in, I was unable to verify his statement. At this point the Ore is Nodular Carbonate rather coarse but heavy, and would, no doubt, produce well. It is almost certain that at some distance from the out-crop, and under a thick cover of rock, this bed would consist almost exclusively of the Nodular Carbonate the Hematite found along the outcrop being due to the modifying action of the atmos- phere upon the exposed carbonate.

Besides the line of exposure, and of acce&oible mining of this ore, on the west and northwest side of the Quarry Run, ranging above and below the Furnace, in all about half a mile, the Redrielt Ore, rising with the rocks in an eastwardly direction, shows itself at various places along the slope of the hill on the eastern side of tlie Run, in the neighbourhood of Oarr's dwelling.

The Second Ore of the present group is that known at the mines connected chiefly with the Henry Clay Furnace, as the Martin Ore,

and at those which were wroaght for Woodgrove, as the Oum Spring or Ba$i Ore, These, I have satisfied myself, occupy the same geological pontion, and thej agree in composition and in the associated rocks. This Martin Ote is separated from the Bed-beU by some twenty-fiye to thirty feet of flaggy sandstones and shales, furnishing beds of excellent material for grindstones. It has been wrought by benching in a winding line along the face of the hills aroond the sources of Quarry Rnn and other neighboring streams, through a distance, on the Pridevale property, which, continnoosly measured, would probably amount to two miles. In all these open- ings I found, by the specimens left on the banks, that the ore is of nearly a uniform quality, being a hliie nodular carbonate of iron, of rather fine grain, covered with a rich scale of red oxide. The ore is embedded in black and oofareous shales, and oonsbts partly of nodules, placed at irregular intervals in psrallel horizontal courses, and partly of one or more layers of nodules, thicker and more closely placed. At the locality wrought by Mr. McKelvy last year, where alone I had an opportunity of inspecting the face of the ore, I found, in the npper ten feet of shales exposed in the bench, four courses of nodules, equivalent, I think, to a continuous bed of six inches. Below these, and separated from one another by eighteen inches of the same shales, are the two main courses or layers, amounting together to about twelve inches. In some places, the aggregate thickness would perhaps be greater ; in others, much less.

The shales associated with these layers, so far as seen exposed, are soft and crumbling, and have therefore greatly favored the deep benching which has already been so extensively carried into theuL Along the line of these openings, there are many intervals where the same mode <if mining may yet be continued; but the great body of the ore in these localities can only be reached by a systematic plan of drift mining, for which favorable positions could easily be found.

It is to be borne in mind, thst the Martin Ore along a part of its outcrop on the Pridevale property, hoe not been mined in any way. The long hill-side, where the Hematite Ore is now mined, most, at a lower level, contain this Ore, and would offer a favorable position for reaching it by stripping and shallow benching; and the same remark applies to the slope connected with the former, which lies nearly opposite to, but somewhat further up the turnpike, than the Martin banks, near the old Furnace. It is highly desirable to have this Ore traced and proved along the range referred to, as well as in other blank spaces which have not been benched upon. It is a pro- ductive ore, and seems to have been mined advantageously along the whole extent of the openings.

The Oum Springe or Roee Openinge are chiefly in this Ore. These are situated in the slopes surrounding the head waters of a stream lying between Quarry and Middle Kuns, and being nearer to Woodgrove Furnace, were wrought, I believe, entirely for its use. Judging by the fragments of ore left on the benches, it does not

differ from the material obtained at the Martin Ore Diggingn above described, and its geological position is the same.

The great Cliff Rock is seen on the hill above its ontorop at a level vertically over it of some forty feet. The benches exposed black and ocbreons shales, and are continued along the edge of a deep winding valley, for upwards of half a mile. The scattered nodnles of the upper part of the bench would be equfvalent to a layer of three inches. The lower layers were covered up by the fallen shale ; but according to Carr, who wrought the mine last, they con- sisted of two adjacent courses, in all about twelve inches, a thick- ness probably not overstated.

The Third Ore of the Martin group is what, from its mineral as- sociation, may be termed the Flint Hematite, Its position, geo- logically, is some twenty or twenty-five feet above the Martin bed, and like the latter, it is enclosed in a mass of black and drab and ochreous crumbling shales. The chief mining in this Ore is in a line of benching along the eastern face of the hill, which forms the western boundary of the comparatively level ground marked by the old mines of the Rock and Martin Ores. Here its long line of out- crop affords favorable opportunities for drifting, as well as bench work. It has already been mentioned, that the Martin Ore ought to be explored, in a parallel line in a lower level, and I may here add, that the Rock Ore, or next higher bed, is to be worked for a short distance above it ; but, as yet, the operations in this hill have been confined to the Flint Hematite.

In the drift now advancing in this bed, I found the Ore proper in the form of an irregular stratum, varying from one to two feet in thickness, consisting of a dark brown, rather compact Limonite, or Earthy Hematite includinf nodules or lumps of clay, and resting on a mass some two feet thick, of a nearly flinty rock, which occa- sionally passes into an impure ore. I observed, also, in the overly- ing shales, irregular seams of an earthy variety of pipe Ore. From this line of workings we may count with some confidence on an av- erage thickness of fourteen inches, and 1 think we may estimate the strength of the ore, /ahen properly eulled, at not less than forty-two per cent. But care is needed at the ore heap to prevent too great an intermixture of earthy matter with the good ore. The large lumps obtained from the mine ought all to be broken, to release the ore from much of the included or adhering earth and fiinty ma- terial.

The Fourth Ore of the Martin group is that known variously among the miners as the £oek Ore and England Ore. This occurs also in dark crumbling shales, at a height of from twelve to fifteen feet above the Hematite or thirty to forty feet above the Ma/rtin Ore, It has been very extensively mined by drifts and benches, on the level high grounds, from which the conglomerate has been swept off in the centre of the Laurel Hill axis. In the low hill, at the upper extremity of the railroad to Henry Clay, and near the head of Quarry Run, it forms a nearly horizontal sheet, at a small depth below the surface. Here it has been removed aroond the

oQtorop, and has been entered on nearly every side by drifts, leav- ing, I apprehend, bnt a small fraction of the original mass of ore in its place, and that in a condition difficult to be mined. There are points, however, in this locality, where, perhaps, it may be advan- tageously entered, although the remaining area of ore is certainly not great.

In the old drifl, which was reopened for our inspection, I found the Eoeh Ore to consist of a layer of large nodule$ or tuggafUy as the miners call them, consisting of rich blue carbonate about five inches thick, associated with a dark bluish and purplish Roeh Ore, made up of round granules, of a dark purplish brown color, era- bedded in a bluish paste. This is properly an Oolitic or Fishr roe Ore, a mixture of oxide and carbonate of iron, and passes into an oolitic limestone, with which, without some care, it is liable to be confounded. Excluding the limestone, I could not, from the ex- posure in the drift, form any exact estimate of its thickness ; but the two Ores together may, I think, be set down at ten inches. The miners who have worked in this locality, affirm it to have been much thicker ; but it appears to have been in this respect remarka- bly fluctuating.

The England or Iock Ore cropping higher than either the Mar- tin or Hematite Ores, should be sought for along the whole extent of the hill-sides, where either of these ores have been benched upon ; and should the ore prove as good as in the old mines above described, the extent of accessible outcrop thus exposed will im- part to this bed great value.

The Fifth or last Ore of this group is a meagre, flaggy ore, inter- mixed with some good knots of Br&tcn Limonite, which is obtained by sarface stripping and shallow benching in the neighborhood of the Roch Ore mines, and is found in the olive shales and shaly sand- stones that overlie the dark crumbly shales, in which the Eoeh Ore is embedded. No sufficiently extensive openings have been made in this layer to determine its value. Should it prove of real impor- tance, it would be accessible along a great extent of outcrop.

From the geological position of the group of Ores just treated of, it is evident that they must crop out in all localities where the strata next below the Great Conglomerate have been laid bare by denuding causes. As the lower ledge of the Conglomerate rises from the bed of the Cheat, a short distance below the mouth of Quarry Run, and thence ascends to arch over the mountain, this stream has there carved its channel in strata subjacent to the Con- glomerate, and not far removed from the beds, including the Martin group of Ores. Indeed, it has for some time been known that the Bed-belt Ore shows itself in this immediate vicinity; and in the course of my late explorations, I found beneath the Great Cliff, a considerable thickness of dark shales, exposing nodular Ore cor- responding to the Martin or England beds. This locality is about one-eighth of a mile northwest of the month of Quarry Run, and is undoubtedly the geological place of these ores. But whether the beds would prove as rich and thick here as where the heavy cliff

has been removed, is a point onljr to be settled hj actual mmmg on the spot. On both sides of Qaarry Run, near the Henry Clay Far- naoe, these ores must also take their plaoe. None of them, however, bat the Bed-belt has yet been explorerl or mined in that vicinity.

The Snd or Stratford Group of Ores,

The Second group of Oree, of which the Stratford may be as- sumed as the type, is included between the top of the Great Con- glomerate and the next saperior mass of heavy bedded rocks. This overlying mass is a rather coarse argillaceous sandstone, from twenty to twenty-five feet thick, forming, where weU exposed, a distinct cliff, which, being the first mass of hard rocks above the Stratford group of ores, becomes a valnable guide in following their outcrop. The interval between the Conglomerate and this — which we may call the Stratford Cliff Rock — is occupied by olive, buff and blackish shales, passing into greenish and brown flaggy sandstones, and in* olading thin beds of quite compact gray sandstone.

The lowest of this important group of Ore beds, is that opened at Nick Carres bank and which we may designate as the Carr Ore. Its place, geologically, is some twenty-five or thirty feet above the Great Conglomerate, and its crop is seen on the turnpike, near the horse trough. At Carr's opening, about half a mile northwest of the Henry Clay Furnace, in the upper six or seven feet of the bench, are scattered nodules of rich Carbonate, at the base a course of bluish Plate or Flag Ore, in large oblong masses, from six to seven inches thick. These are regularly laminated, the layers being marked by different tints in the crop fracture, giving the whole mass the appearance of a laminated sandstone, or sandy slate, into which, indeed, the bed occasionally degenerates. The laminar sur- faces of this as well as the adjacent slates and sandstones, are oc- cupied by carbonized remains of leaves and other vegetable im- pressions. The whole mass, including the nodules above, may be estimated at ten inches. It is a heavy ore, found to work well at the Anna Furnace, and promises to be persistent Below the heavy plate is a layer of mnoh poorer Rock or Sandstone Ore, some fifteen mches thick, and a few feet lower is a thin coal seam, the first met with above the Conglomerate.

The Second Ore of the Stratford group, is the Straord Ore proper. This lies about twenty feet higher in the strata than the preceding, and is separated from it by a coal seam, which at some points is siud to be three feet thick — it is certainly, I think, as much as two feet. The ore lies in bluish or lead-gray shales, and where inspected by me, in a drift on the mountain road, consists of three courses o( flat nodules and larger roundish masses of hhts argilla- eeoue Carbonate making an aggregate thickness of about ten inches. A long line of benching has been pursued on the outcrop of this ore, eastward of the drift in question, and from what I heard and observed, these mines have Airnished a large amount of ore. The ore is a compact, sometimes rather rough and sandy Oarbonate Iwl

it will yield well for an ore of this class. The shales along the oatcrop are crnmblj and easily removed ; bat in the drifts examined, they snow a degree of compactness whieh mnst add somewhat to the cost of mining. These as well as the Oarr Ore have a long line of outcrop yet nntouohed, to which hereafter attention may he properly directed.

Above the true Stratford bed, at a distance of about twenty-five feet, we met with the Third Ore of the present gronp, the Black- band Ore, This, as indicated in its name, occurs in a mass of black and dark gray shale, the crop of which is seen on the Mountain road, a short distance west of the Strafford drift. This shonld not be confounded with the peculiar black carbonaceons ore found in the Scotch and English ooal-measnres known as the Black-band and which is of a black color. In the present case it is not the ore, but the associated shale, that has that hue. Still further west, or down the mountain, it has been opened below the road, at a point ad- joining the o1<l opening of the Stratford Ore. Here the Black-band discloses itself in two courses of large irregular nodules of good ore, in all about eight inches thick, the upper course consisting of ear* bonate with brown oxide; the lower chiefly of the unaltered car- bonate. This Ore is to be looked for above the Stratford band, along its outcrop generally. At the old opening just referred to, owing to a slip or displacement of the strata, the Ore conld not be confidently pursued.

Above the black shales of this bed are sandy slates, and olive and bluish shales and flaggy sandstones, occupying a thickness of about thirty -five feet. These in the outcrop on the Turnpike give some indications of Ore, and mark, as I think, the general position of the ore beds recently opened on the Duval Greek and on Middle Bun.

The former of these openings, a little more than one mile north- east of the Anna Furnace, exposes a thick mass of bluish-gray sandy shales, the laminiB of which are crowded with the remains of plants. Near the top is a layer of nodular blue earbontUe of excellent qual- ity, below tnis, two courses of large nodular numea or sune of inferior quality, and at bottom another layer of the heaty nodulee making in all about five inches of good and about ten inches of a poorer but still available ore. This mine is near the dwelling of John Ooles, by whom it is worked, and is not on, but adjoining the Pridevale property.

The other opening, known as Sam Colee Mint, embraces both sides of Middle Run, and brings to view a similar series of bluish aandy fossilifcrous shales. In the upper part of the bench are a few small nodules of heavy blue ore ; beneath these a plate, about two inches thick, of sandy but moderately good ore ; and at bottom a layer from twelve to twenty-one inches thick, composed sometimes of large suggans of a rather meagre but probably available shelly ore, in- closed in shale, and sometimes of a rather variable bed of highly fer- ruginous bluish shale, which, taken in the mass, can be of litUe or no value as an ore.

Further op the stream hoth here and at tho preceding looalitj, we should look (or the lower Strafford Orm before meotiuned, and between the openings on Middle Rna and tlie old Stra{ford Minn OD tbe Tarnpike, a distance of more than two miles, there is great scope for mining in all these lajera of ore, by benching as well as b; drirts.

The recent opening on the Honntain Turnpike, near the Horse trough, ia evidently m tbe upper beds u( the Stratford group, and from tlie general richness of the layers exposed, pvea promise of a persistent vslne in these, as well as the Ueer Stratford Oru. This should enoonrage exploration along their outcrop close in towards the base of the btrdtford ClifF rock above described.

The Sd, or KotHm Oroup iff Ore*.

This aasemblejie of Ore-beds is included between the upper limits of the Stratford Cliff rock, and the bottom of the four-feet vein of coal, an interval of abont one hundred and ninety feet, embracing shales and sbaly sandstones aod beds of Coal and Fire-clay, and in some locslicies one or two thin and variable conrses of Limestone.

Tbe loaut of this group, the Norri* Ore, has its place near the upper limit of a mass of shales and shaly sandstones, which, in geo- kioal position, is next superior to tbe Stratford Cliff ruck. This ore is found in and directly beneath the bed of Fire-clay which sup- ports the Norris vein of ooal. It ia ohiefly a frrown oxide or tarthy hematite of good quality. Above the Co, which at some points is a good seam, three to foor feet thick, ia anotlier mass of Fire-clay, of a compact and fine grain, called here Whetstone, end which has been very largely dag for the manufacture of Fire Brick. Keating on this is a thin plate of coal. iJttle ore is found in the upper Fire-clay but I learn that a good thickneaswas mined in the benoties extending through the lower Fire-clay. The openings of the Norris Ore have been thus far confined to so mach of the broad slope of the mountain west of the Stratford Cliff Hock, and lying over it, as intervenes between the Houutnin road and the head of the next great hollow towards tho North. Here the Fire-day and Ore have been benched upon over quite a large snrfaoe. There is still, I think, a good extent of tbe outcrop of this ore, and the aasociated valnable materisls which remain natonohed.

Above the Norrit Ccal, and separated from it by some twenty or twenty-five feet of shales, ooonrs ibe Second Ore bed at the present group, which, from its usual association with limestone, we may call the Limatone Ore bed. It Ues a few feet beneath a thin coal seam, and is associated with Fire-clay, Shale, and a r: ' ' j.mts Limestone, into which, st places, the ore seeme I . . . No

Xrtant opening has, llKlieve, been made in tlil- i,...i. uiai its I remains to be determined by future exploruLiniiH. Paaaing an interval of some thirty feet, oocnpii J by -iliulc's nod shaly sandstones, in which no ore has yet been t>pUiri.'il. we reach the level of another thin coal vein, above which, i

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buff Bandstones and sandy shales, oocnrs the Third Ore bed of the present group — the one recently opened by Olellan in the hollow, about three-quarters of a mile east by north of the Anna Furnaces ; this lies a few hundred yards higher up the hollow than the drift of the four-feet coal once wrought here. In the bench thus far laid bare, are three courses of nodules in bluish sandy shale; below these a thin layer of coarse plate ore, and at the bottom of the bench, a double flag of laminated sandstone, about twelve inches in thick* neas, impregnated with carbonate of iron ; another course of sand- stone, containing still less iron, lies some fifteen inches beneath the latter. The twelve inch flag above mentioned, is in large part nothing better than a ferruginous sandstone, and will I think, be found worthless as an ore. In the mass, it certainly cannot contain over ten per cent of iron. Parts of the npper layer, and all the heavy nodules are of pretty good quality, but, unless the opening should prove more productive of good ore than at present, I would advise its being abandoned. Search should be made in ttie shales some twenty feet above, and as much below, for other and perhiq)s more favorable openings. This interval appears on Deckers Creek to have furnished some good ore.

It is, I think, in the space next above the Clellan Ore, that we are to place the AMy Ore of the Woodgrove tract, which therefore, provisionally, we may designate as the Fourth ore of the present group. The Aehby Ore has been extensively mined, by benching around the face of the hill, on the south side of the valley of Middle Run, between one-quarter and a half mile from Woodgrove Fur- nace. It occurs in a drab ochreous shale, associated with black, crumbling slate, and probably a thin plate of coal. The mining having been discontinued some years, no opportunity was afforded for determining the thickness of the bed. From the miner who had wrought in this ore, I learned that it lay irregularly in the shale, sometimes a foot, and sometimes much less in thickness. The frag- ments left on the benches, prove it to have been a brown oxide ore of good quality. The old benching has, I think, removed as much of the ore from this line, as can be conveniently or cheaply reached by this method ; but the line of benching admits of being extended, and this ore merits an early exploration, as its quality, and ita vicin- ity to Woodgrove, would give it, if in sufficient quantity, very great value.

A Hematite has been opened on the face of the hill, on the oppo- site side of the run, which seems to correspond in geological position to the Ashby Ore. The extent of this will probably soon be made known.

Returning now to the section in the vicinity of the Anna Fur- nace, we meet, at the height of some fifty feet above the Olellan Ore, a bed of Fire-clay, containing at bottom nodules of ore, and overlaid by the small coal seam known as the Blacksmith vein. These are immediately overlaid by a mass of heavy bedded argillaceous sand- stone, which, at a short interval is capped by the Four-feet Coal. The ore beneath this ledge, and associated with the Blacksmith vein,

18 now being explored along the turnpike, at a short distance below the ledge in qnestion, and was formerly dag into farther np the road, a little below its level. It here furnished some good brown oxide.

Above the sandstone jast mentioned, which was here a thickness of upwards of twenty feet (although entirely wanting on Deckers Creek,) we meet the tire-day and shales subjacent to the Four-feet Goal. In these there occurs what here, as well as at Decker's Creek, has long been known under the name of the Swuher Ore, This was at one time largely mined on Decker's Creek, where it formed a band of from six to ten inches of heavy carbonate and oxide, and was accompanied by a stratum of limestone. This limestone band is absent in the vicinity of the Anna Furnace.

Considering the coal seam at Woodgrove as the equivalent of the Four-feet vein of the Anna Furnace, the limestone ore which is found beneath that seam would correspond nearly, if not exactly, in geological place with the Swisher Ore. Where examined by me, in the drift near the Meetinghouse a little northeast of the Furnace, this ore forms an irregular bed, lying upon, and more or less blend- ing with, an argillaceous limestone — the two together making a thick- ness of two feet, of which one-third may be estimated as ore. Two feet of calcareous fire-clay intervene between the ore and the bot- tom of the coal, the thickness of which, at this drift, is about three feet. The ore is, throughout, more or less calcareous and argilla- ceous, but in the main it is a rather rich carbonate of iron.

An Ore, corresponding in position and character to the Swisher Ore, has been opened at the head of the hollow in which Clellan's mine is situated, and is known as the Butler Ore. It occurs beneath, and quite near the Four-feet vein of coal which crops out on the ridge at a short distance higher up, and from its richness and re- puted thickness, deserves to be carefully examined along the exten- sive line of outcrop in which it is here accessible.

The 4th, or Haines SnaJce-Den Group of Ores,

This group is included between the Four-feet and Two-and-a- half -feet seams of Coal — an interval of about one hundred and eighty feet — composed below chiefly of coarse and sometimes conglomer- itic sandstones, and above, of crumbly argillaceous and calcareous shales.

At the Anna Furnace, it consists of two belts, the first or lower of which has been for some years mined under the name of the Haines Ore, The Haines Ore lies in a mass of buff and olive sliales, some twenty feet in thickness, interposed between the two very thick masses of sandstone which are largely exposed in the hill-side immediately east of the Furnace. The lower of these masses, about forty-five feet in thickness, forms the cliff next above the Four-feet Coal ; and the upper mass, which is thicker, and includes beds of coarse millstone conglomerate, and which in its western dip sinks below the Cheat, a little west of the Furnace, forms the cliff at a

still greater elevation. The Haines ore bed in this vicinity has been min at several points, and has furnished a bratcn oxide of very good qnalitj. It is accessible at nnmerons places along its ontcrop, in the lowest bench of Lanrel Hill, from the Anna to Woodgrove Furnace. On the slope east of Dnvall's, (the old Post-Office,) on both sides of the stream which flows past John Cole's opening in the Stratford Ore, at a distance of about one-and-a-half miles from the Anna Furnace, this ore has been mined extensively, and some of the benches recently wrought have been found quite productive both as to the quality and thickness of the bed.

In the immediate neighborhood of the Woodgrove Furnace, the Ore which I deem geologically equivalent to the Haines Ore, may be traced for a considerable distance along its outcrop. It lies in the shales separating the two cliffs of sandstone, which display them- selves in parallel ranges in the hill, extending from opposite Wood- grove, in a northeast direction, along the margin of the northern fork of Middle Run. Here I found the shales to contain nodular Carbon ate qf Jron and I have no doubt that some ore of this description has been mined in the benches of the vicinity ; but most of the Hames ore here, as well as near the Anna Furnace, is the brown oxide produced by the decomporition of the carbonate. In the re- cent explorations, from one-third to one-half a mile above the Wood- grove Furnace, in this line of outcrop, the Oxide or coarse hematite is exposed in a thickness of from six to fourteen inches.

Near the Anna Furnace this ore appears to have been uniformly of good quality, often in very large irregular lumps, spproaching the character of hematite, and in beds varying from six to twelve or fourteen inches. Hitherto it has been mined exclusively by strip- ping and benching.

As the Hainei Ore is one of the most persistent in thickness, and one of the purest and richest brown ores met with in this re- gion, it deserves to be systematically pursued throughout its entire outcrop, and in suitable places to be explored by drifting.

The Utt Ore of the Woodgrove neighborhood, occurs at a lower level in the rocks than the Haines Ore. At the old diggings, about one mile northeast of the furnace, this ore is seen in a fire clay shale, a few feet below a heavy bedded sandstone, corresponding, I think, to the lower of the two cliffs before mentioned. Twelve or fifteen feet below the ore, a coal seam about three feet thick has been opened, which I am inclined to regard as the main Woodgrove vein. The Utt Ore would, in this view, be in the shales immediately above this coal, and beneath the lower of the two cliff rocks. Where exposed, it is a meagre brown oxide, and would seem scarcely wor- thy of further pursuit.

The Second Ore within the geological limits now treated of, does not present itself clearly at the Anna Furnace, but forms a very important bed at Woodgrove, where it is known under the title of Snake-den Ore. The position of the Snahe-den Ore at Woodgrove, is at a level some twenty feet above the upper cliff rock, at the Woodgrove Furnace, and about fifty feet lower than the coal seam

of that yioinity, which I regard as identico] with the Two>and-a-haIf feet vein of the Anna Fnmace.

The Snak&'den Ore at Woodgrove has been traced and partially- benched on the hill westward of the fhrnace, following, at a short interval, the apper level of the cliff rock, and with this descending westward, nntil it sinks below the bed of Middle Rnn, about half a mile below the fnmace. It consists nsnally of a single coarse of roassive rock-ore, varying from five to ten inches in thickness, over- laid by ommbling shales and clay. It is divided by rectangular joints or natural partings, into blocks of a square form, which in mining are readily separated from the bed, and lifted without any mixture of impurities. The ore is in reality a bluish rock, at times sandy and micaceous, highly charged with carbonate of iron, which for some depth, and often throughout, has been converted into red oxide of iron. In the unchanged interior it contains quite a con- siderable proportion of carbonate of lime, along with carbonate of iron, and taken in mass, as presented in the ore heap, is to be re- garded as decidedly calcareous ore. It is unquestionably well charged with iron, bat deserves a very careful analysis for its lime and other ingredients. The form of the land along and near its outcrop, will render it accessible by shallow and easy benching over a large sur- face, and its persistency throughout the extensive Kne over which it has been explored, gives assurance of its abundance. From the gen- eral shallowness of its cover throughout this range, we may antici- pate no material diminution in the oxide crust, or shelly portion of the ore.

A careful examination of the geological place occupied by this belt of ore at Woodgrove, both in regard to the small coal seam above, and the cliff saudstone below it, leaves no doubt as to the position in which it should be found in the neighborhood of the Anna Furnace. This would place it among the olive shales and shaly sandstones on the river road, beneath the store, a short dis- tance lower down the river than the Furnace. Here, however, it does not present Itself in a regular bed, as at Woodgrove, but in the form of nodular masses, bluish within, and deeply covered with a brown scale, occurring rather sparsely in one or more thin beds of whitish fire-clay shale. The ore, both internally and externally, re- sembles the best of that which is mined near Woodgrove ; but thus far, at this point, it has not disclosed itself as an available bed or seam.

As the Snaie-d&n Ore has been clearly traced from the Spring Hill Furnace to Woodgrove, and from the latter point to within half a mile of the Anna Furnace, its absence, in any available amount, directly at the Furnace, should not discourage efforts to fiud it on the property of the Company, within this as yet imperfectly ex- plored interval. There can be no doubt that the ore formerly dug at Baker's, half a mile distant, belongs to this band. The Two-and- a-half-feet Goal, which forms a valuable guide in this tracing — lying high in the shaly hill facing these openings on the west — shows it- self in a field somewhat nearer the Furnace, and is evidently caught

just at its oatorop, in the slope of Meeting-Honse Hill, as it descends towards the brook north of the railroad. The form of the in this vicinity is such as to make it certain that the strata, inclad- ing the Ore — and we may hope, therefore, the Ore itself crops oat in the hollow of this brook, at a lower geological level, however, and therefore somewhat further west than the hill-slope on which the- coal- wash has been ei posed.

It is a point worthy of special note, but which seems hitherto to have escaped detection, that the Snake-den Ore, in chemical and mineralogioal characters, bears the closest resemblance to the Scott ore, which, on Dockers creek, and at the Clinton Furnace, has proved so permanently productive. Their identity in regard to geological position is not so susceptible of exact determination; but my observations on Booth's creek, near the Clinton Furnace, were sufficient to prove that the Scott Ore lies in the same general belt of rocks with the Snahe-den Ore and is truly, in that region, its equivalent. A systematic and thorough exploration of the ground here referred to, by means of ditches, or costines, ought early to be made, as the vein of ore, if in force here, would, from its proximity to the Furnace, be of very great value.

The deoosits of Ore next to be mentioned, are strictly speaking, partly within and partly above the limits of the present group. These deposits consist of an earthy and sandy brown oxide, found very near the surface of the level tract which extends from the Anna Furnace, for some distance along the base of Lanrel HiU. The ore has been dug at several points ouite near the Furnace, and at Bowers and other places in the neighborhood. At all these localities it occurs in the loose sand and gravel which overspread the flat, and it is not directly associated with any of the subjaoent strata. Considered in regard to its origin it belongs to the class of hog oreSj formed by the infiltration of water, charged with iron, into the loose surface materials. Deposits of ore of this kind natu- rally suggest the proximity of ore beds of original formation, from which the water has derived its charge ; and in many cases bad ores are actually traceable to this source. But it even more fre- auently happens that the infiltration comes, not from seams or deposits of ore, but from shales and slates containing much diffused sulphuret of iron, which, through the action of the air and water, furnishes soluble compounds of the metal to the percolating rains. The ore of these superficial diggings near the Anna Furnace, is often quite rich, and being accessible over quite a large area, is of some value as a local resource.

The 5thy or Big Coal Group of Ores,

The Fifth and last group of ores included in the Pridevale prop- erty, lies in the interval between the Two-and-a-half-feet Coal and the bottom of the Big Coal or Seven-feet vein. With the exception of bands situated near the bottom of the Big-Coal, these ores are

all Hroestone ores, or have been derived by oxidation from ores of that class.

The First of this group of ore beds has not yet been distinctiy recognized on the northeast or Pridevale side of the river, but is well exposed on the opposite side, on the old Morgantown road, a few hundred feet beyond the lower ferry honse. Its place is well marked by a coal seam of abont twelve inches, lying above and separated from it by eighteen feet of yellowish and brown shales. This ore is a sandy argillaceous knotty rock, forming a bed of about twelve inches thickness, bluish within, but rapidily exfoliating in scales of brown oxide. In quality it much resembles the Snake- den Ore, but it is more calcareous. Proof is yet wanting of its con- tinuity over any considerable space. The same belt of shales, examined on a ridge about a quarter of a mile higher up the river, disclosed to me very little of the ore. Followed under deep cover, it cannot be expected to maintain its character; but from the absence of the oxide crust, will probably exhibit too large a pro- portion of the other ingredients.

This bed merits further search on both sides of the river. Its place in the limestone hill would be near its upper end, at some twenty feet above the Coke-Railroad, and abont thirty feet below a thin ooal, which in the section is marked (A).

Contignous to this coal seam, both above and beneath, a very meagre earthy ore is found, which has been mined at various points in the hollow north of the Coke Yard. This is associated with cal- careous shale and fire-clay and consists of mere shells of ferruginous sand and clay, too poor in iron to be worth mining. I will, there- fore, not enumerate this as one of the available ores.

At a level from twenty to thirty feet higher than the Small Coal, already mentioned, and separated from it by shales, sandstone and a considerable bed of yellowish limestone, we meet with a very remarkable ore bed, which has thus far, however, proved too thin to be of much value. This is wrought by a drift on the east- ern flank of the Big Coal hill. It is associated with calcareous shale and impure limestone ore, but the band itself is a very pon- derous nodular ore of a deep colcothar brown color, so rich and pure, that if reduced to powder, it would no doubt, form a good pigment, similar to Spanish brown. Its thickness thus far, has nnt averaged more than two inches.

Above this level, the limestones and limestone shales which oc- cupy a good part of the next one hundred feet of strata, present, where decomposed by exposure, shelly fragments of yellowish and brown earthy ore ; but this being the product of purely surface action, gives no true evidence of beds of ore. At a still higher level, within thirty feet of the bottom of the Big Coal, occurs another thin plate of coal, below which, in the fire-clay shales, we meet with irregular courses of limestone and of ore. These materials are exposed in numerous diggings near the crest of the limestone hill, and agam on the road approaching the Big Coal. Some thin plates of rich carbonate nave been found in the shales occupying this

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podtioD, at one or two points in the limestone bill ; but here, and at the openings near the Big Coal, the ore is principally made np of concentric shells of earthy brown oxide, with large interRpaces occa- pied by yellowish clay and sand. Where freed from the great ex- cess of earthy matter, this ore will be fonnd valuable for mixing with heavier and more refractory materials. A similar but richer ore, having the same geological position, has been opened by Moore on his own land, ac(joining Hasties on the opposite side of the Cheat. These ores being, I thinic, in great part the prodnct of a decomposed ferraginons limestone and shale, lying near the sarfaoe, will become poorer and more calcareous when followed under a deep covering of rock. But in the localities mentioned, they range for a wide space near enough to the surface to retain their character of oxide ores.

I now come to the last belt of ores of this group : that included in the fire-clay and shales, extending below the Big Goal, through a depth of from twenty to twenty-five feet. This, at some localities, ia a belt of great importance, as well from the persistency as from the richness of the ore. At Oliphant's Furnace, northeast of the Anna, about seven miles, it consists of a fine-grained, compact, rich nodu- lar or plate carbonate of iron, from five to six inches thick, within a few feet of the bottom of the Big OoaL Similar plate and nodular ore has been mined beneath this coal, on the hul of the Eclipse Rook, below Pride vale. Under the mouth of the coal mine, two drifts have been carried for a short distance into the shales under the Big Goal in search of ore. The lower of these exposed a plate of very rich blue carbonate or Oliphant Ore but too thin to encourage further pursuit. In the upper drift, the roof of which is a foot or two below the bottom of the Big Goal, the light bluish arlaoeous shales include several scattered courses of small nodules, and one course of large suggans, all of a bluish white color, and rich in car- bonate of iron. Near the coal openings, these shales have, by strip- pings, fxirnished a large proportion of similar ore ; and at tiie mouth of the coal mine, a ditch recently dug for the purpose of draining the works, in penetrating the fire-clay shales for some three or four feet below the coal, has disclosed the same nodules and suggans. Judg- ing from the amount of ore seen at these openings, I would estimate the contents of the fire-clay shales, in a depth of six feet, in this particular locality, as equivalent to a plate of ore of about eight inches.

On the neighboring coal-hill, at a distance of about' fifteen feet below the cool, benchings are now in progress which furnish a coarser ore of the same description, which, from the name of the operator, may be designated the Golline Ore. These openings dis- play scattered nodules of heavy blue ore, forming from three to five courses in a thickness of five feet of soft, crumbling shale, and be- neath these a mass of flaggy ore separating in thick plates, with rounded edges, sometimes covered with a dark brown scale. The whole thickness accessible in these openings, is from nine to twelve inches, the greater part of which is a moderately rich carbonate ore.

Ab this Ore is obviously a laminated shale, heavily charged with earhimaU of iron, and is therefore part of the original stratification, there is no probability of its being changed in quality when traced inward from the outcrop, more than in any other direction; and there is therefore good indncemcSit for hereafter following it into the hill by drifts.

As the area underlaid by this Ore on the Pride vale property is not very extensive, even supposing the ore to contiuue equally val- uable throughout, I have made some examinations on the opposite side of the Oheat River, on the lands of Hastie, Stilwell, Haco and Coombs, to learn its range and probable thickness in that direction. At Hasties and StilwelPs, a rich nodular carbonate is found, in the shales beneath the Big Coal ; bnt the absence of any regular open- ings prevented my learning anything definite in regard to the num- ber and thickness of the layers. On Haco's land it has been imper- fectly exposed on the margin of a small brook, and is said by the proprietor and others to occnr in two courses, of which however, I could see but one. This is fom one and a half to two inches thick, and is of the very finest quality of blue carbonate. On the margin of another brook, but a short distance from the preceding, on Coombs's property I found, in place of the shales, a band of similar ore, varying from three to five inches, and nnmerons fragments of the thin plate ore, which obviously lies a few feet below the other. In this locality, therefore, six inches of the heavy fine-grained car- bonate or Oliphant Ore, are accessible. The distance of this point from the Anna Furnace is something more than one-and a-half miles. These ores, if present in the neighborhood of Woodgrove, are of course confined to the range of the Big Coal, which lies high in the hiUs adjoining the Cheat River, and therefore beyond the Pridevale tract.

Gekebal Remarks ok the Ores.

It shonld be borne in mind, as a matter of much economical in- terest, that the ore formations consist of shales and shaly sandstones, containing a general impregnation of carbonate of iron, which, in particular layers, becomes the predominating ingredient, forming nags and nodular courses of good ore ; and that as the ore gradu- ates by insensible degrees, into the shaly mass, much skill and vigi- lance will be necessary to prevent the substitution of a merely fer- ruginous rock for the ore, which it so much resembles.

It should also be remembered, that the productiveness of an ore bed along the outcrop, where mined by stripping or shallow bench- ing, does not necessarily increase, as often supposed, or even continue the same, when the ore is pursued by drifting under a deeper cover of rock. As a general rule, the brown oxide ores of the coal meas- ures are the pro<lnct of chemical changes, due to the access of the air and water to the blue nodular or carbonate ore, which appears to have been very generally the orial form in which the iron was accumulated in the carboniferous strata. Henoe, when followed far

onder the rocks, these Brown Orm or Limonites are commonly, al- thougli not always, seen to pass into the condition of blae nodules of carbonate, with ochreous scales, and finally into the solid and unchanged blue lamps.

The Brown Ore when tolerably free from earthy matter, is richer in metallic iron than the best blue lump met with in the ooal measures. The former often contains more than one-half its weight of metal ; the latter is of good average quality when it at- tains to one third. In the case of the Haines Ore and the Snake- den Ore, the form of the ground along the outcrop is such as to afford a comparatively wide belt, under shallow cover, and thus to favor the complete oxidation of the mass, even for some distance within the immediate line of outcrop. Similar remarks are applica- ble to the limestone ores. These oeing principally derived from beds and nodular courses of limestone, highly charged with carbon- ate of iron, are found, at and near the outcrop, to consist of a light brown ore, generally in irregular concentric snells, including earthy matter, the residue of the limestone after the solution and removal of its carbonate of iron. When pursued under deep cover, such ores may be expected to pass into masdve unchanged limestone rocks.

The hhio nodular catenate and plaU Ore being an original con- stituent of ttie strata, is not necessarily subject to change of composi- tion when followed under cover by drifting, but when thus explored, will show only such alterations of thickness and purity as belonged to it when first deposited or collected by segregation in the strata ; such will be found to be the result with the Red-belt and Martin Ores, and with the Oanr and Stratford and Collins beds. In these oases the only change to be anticipated, is the disappearance of the brown oxide scales which usually enclose the lumps and plates, at and near the outcrop, and these, in the cases mentioned, form an inconsiderable part of tlie mass. The Snake-den Ore, being in its unchanged condition, a rocky bluish carbonate of good quality, may be expected, even when pursued far under cover, to retain its value as a carbonate ore ; but will, of course, be less productive than an equal weight of the brown oxide, into which it has been trans- formed, along the outcrop and under shallow cover.

Aft a general rule, it should be remembered that the shales with which te ores are almost always associated, are softer and more easily mined along the outcrop than under deep cover, and hence, usually, the ores can be obtained at less cost by stripping or shallow benching, than by mining in drifts. The relative cost of the two methods will, of course, depend not only on the nature of the ma- terial, but upon the compnrative proximity to the Furnace of the respective mines. It will be seen in the details already given, that many of the principal Ore beds of the Pridevale tract, have already been stripped and benched over a considerable extent of their out- crop. But even in the$e eSses, long lines remain untouched while, regards some other layers of Ore little more than a beginning has been mads surfaces mining. The RedBelt and Martin Ores, the

two principal Stra&rd Orei the Swisher and Hainee Oret, the 8nak&- den and the ColUne Ores, have each in reserve a long line o/outerop portions of which will he within convenient reach of each of the three Furnaces,

The Anna Fnrniioe is more remote than either of the others from most of the productive openings now rained. Bat it will he seen, by inspecting the transcerse section B, that between the Fur- nace and the month of Quarry Ban — a distance not exceeding one mile — the Ores of liie lower and middle groups lie in a series of parellel northwest dipping layers or plates, extending from their outcrop on the brow and slope of Laurel Hill, down to the river level, and therefore presenting their edges along the side of the mountain which fronts the river. Here is an important field for exploration, and should the Martin, Stratford and other Ores at these points, prove as good and abundant as at some of the remoter open- ings, it may be found more economical to obtain the Ores by drifts entering along or near the base of the hill, and near the Furnace, than to transport them, although more chef4>ly mined, from the dis- tant outcrop openings.

Of thb Goal Seascs.

Including the nnmerous thin beds or plates of coal, which, at various intervals, are interpolated in the rooks of this district, we may enumerate twelve and perhaps thirteen distinct Coal Seams. Of these, however, only are to be regarded as of any economi- cal value, vix : the Nbrris vein, the Blacksmith win, the cb-halfFeet vein the Four Feet vein — marked five feet in the section — and the Big Coal, or Seven Feet vein. Among them, the last two mentioned are by far the most valuable. A brief reference to the more marked of the others, however, cannot be without interest and importance, since even a thin plate of coal is often a most valu- able guide in seeiin for ores, and in determining their geological position.

The lowest two seams are associated with the Stratford Orea — the lowest of all being a few feet beneath Carr's Ore, and the other be- tween thb and the old Stratford Ore. Of these, the former alone appears to attain considerable thickness, having at some points, ac- cording to Oarr, a breast of about three feet ; but of this measure- ment I have no evidence from my own observations. The Norris vein, at its outcrop in the ore and whetstone diggings, I found to measure more than four feet ; but this is, no doubt, beyond its aver- age thickness, and is, moreover, inclusive of a good deal of carbona- ceous slate. Of the quality of this coal I cannot speak, as it appears never to have been brought into use; but on the outcrop I found it to be slaty. Tlie Blacksmith vein where mined at the crop on the hill side, southwest of Sheets Hollow, was about eighteen inches thick. It was greatly esteemed for blacksmiths' use, and was re- sorted to before the diiscovery of the larger, or Four Feet vein above it ; of its persistency in quality and thickness I have no means of

foriniDg an opinion. All these coals would descend below the lerel of the Cheat, east of the Furnace, and at distances as indicated on the Hcriaontal Section, more and more remote, in proportion to the lowness of their position in the series of inclined strata. Each of them, howeveTy in ite extension upwardi and laterally , would under- lie a very large area on the Priaeeale estate.

The vein called the Four Feet vein is unquestionably the most important belonging to the property, extending, as I think it does, from the Anna Fnmaoe to wooidgrove, and spreading upwards with the rise of the strata eastward, so as to underlie a zone of many hundred, and probably more than a thousand acres. In the neigh- borhood of the Anna Furnace it consists of two benches, divided by a thin and variable layer of carbonaceous slate — the lower bench measuring three feet two inches, the upper sixteen to eighteen inches. At Barney's, on the flank of the mountain, its thickness appears to have been about the same. In the neighborhood of Woodgrove it is somewhat thinner, and owing to a siight disloca- tion, connected with an undulation of the strata near &e furnace, the coal has been pinched and disturbed by the acljaoent heavy rocks.

At Beatie's drift, adjoining the Furnace, it yielded only two feet of coal. In the drifts northeast of this, it is said to have varied from two-and-a-half to four feet. During the summer, when steam power at Woodgrove takes the place of the water power of Middle River, this coal has, I learn, been found very efficient in driving the engine, and for such an use the supply of coal from it would, I think, be ample, without resorting to the big seam on the river hill, a mile below.

In future mining, however, I would suggest opening the seam some distance up the valley northeast of the Furnace; as by that means, not only would a greatef area of the coal be conveniently commanded, but the workings would be less influenced by the undu- lation which traverses the strata in the vicinity of the Furnace. Like flj] the coals uplifted by the arch of Laurel Hill, the coal of the four feet seam has a strikingly cubical fracture. No andysis has yet been made, to determine its ash, bitumen, etc. ; but, judging by its ap- pearance, I wonld rank it among the coals having from twenty to twenty-five per cent, of volatile matter. Whether it is a sufficiently dry coal to admit of being used in the raw state in the reducing furnace, can only be determined by trial.

Of the extent to which the mining already conducted in it has exhausted this plate of coal, I have no means of ascertidning; but from what I have learned of previous workings, I presume that no great impression has been maae on the mass. Hitherto, the mining has been confined to the lower, or three feet bench, the dividing slate serving as a good roof for the works. The Two-and-a-half'' feet aein lying from one hundred and fifty to one hundred and sev- enty feet higher in the strata, descends to the Cheat River near tiie Foundry, and has been opened by benching, and by drifts in the low, terrace-like hill which is prolonged from the Furnace westward.

70S

The same vein is also wrought for local use, at several points in a northeasterly direction, between this and Woodgrove. It shows itself in a heavy smut on the road three-quarters of a mile south- west of that place, and is, I conceive, identical with a seam which has been drifted on in the valley of Middle Run, half a mile below the Woodgrove Furnace.

Passing over the two or three thin and variable plates of coal that intervene, I come now to consider the Big Coal or Seven Feet vein. This fine coal seam, wherever it occurs in the Monongahela valley, is marked by an overlying thick mass of heavy bedded coarse sandstone, capping the high hills, and in many instances forming a lofty cliff impending over the month of the mine. Its available thickness of coal varies, in different neighborhoods, from six-and-a- half to nine feet. In the drifts below the Eclipse Rock, where I measured it, I found the main or lower bench, at different points, 6*6 feet, 6*8 feet, 6*9 and 6 '4 feet, and on an average in this hill, not less than five feet ten inches. In this bench there are no slaty part- ings, except one very thin film near the top. Generally, above main bench there is another of considerable thickness, with a thin layer of slate interposed, and still higher, two other much thinner plates. By the disappearance of the lower slaty land, the two are thrown into one unbroken mass, and sometimes the upper slates also disappear, and the seam assumes its maximum dimensions. At the mouth of the drift above mentioned, the following measures were taken in the descending order : —

Plate of Coal, 6 inches.

Slate, 2 feet.

Conl, 9 inches.

Slate, 18

Coal, upper Bench, 21 "

Slate, 2 "

Coal, main Bench, 5 feet 9 inches.

The coal of the Big vein is highly bitominons, flames abundantly, and produces a good coke, the value of which has been already tested in the Furnace. The area of this coal seam included in the Company's property is in all about sixteen acres, ten of which are in the Big Hills, and the remainder in the adjacent height above Collins Ore banks.

The river hill, about one mile northwest of Woodgrove Furnace, and beyond the limits of the Company's land, contains an area of about six acres of the same vein, the mining right of which belongs also to the Company. This, in connection with any future exten- sion of the operations at that furnace, must prove a very valuable resource. At the mouth of the mine, on the nill-side fronting the river, I found the bed nearly horizontal, with a slight declension towards the southeast. The face of the seam presented the follow- ing divisions in measure :

Plate of Goal, 7 inches.

Black Slute, 18

Plate of Coal 6 "

Black Slate, 17

Main Coal, 6 feet 2 inches.

Of the Limestones.

Id the lower division of the coal-measnres, indadiDg, as already defined, all the strata from the hase of the great Conglomerate to the top of the Foar feet seam of coal, no considerable masses of Limestone are fonnd anywhere in the coal basin in Virginia or Pennsylvania. Bnt Limestone strata exist at some depth below the Conglomerate, and also in the higher divisions of the coalmeasares, both below and above the main upper coals.

On the land of the Company, the Limestone rocks of both these geological belts exist in ample abundance ; using the ascending order, I shall speak first of the Limestone below the Conglomerate. This lies at a distance of several hundred feet beneath that formation — from which it is separated, as shown in the section, by the group of Martin ores, and the underlying red and variegated shales and sand- stones. It is seen cropping out at some points in the mountain slope, eastward about a mile from Quarry feun, whence it has been obtained for the Henry Clay Furnace, and is well exposed in a low northwest dipping shelf, on the opposite side of Cheat Kiver, about half a mile above the mouth of this stream. It forms a low and very broad anticlinal arch, in the heart of Laurel Hill, rising to- wards the Raven Rocks, in a line of cliff, far below the great Con- glomerate, and then gently descending, further up the stream, to dis- appear below its level, towards the opposite or southeast side of Ijiurel Hill. Where fully exposed, its total thickness would amount to aboat one hundred feet, including in this estimate the lower sandy and shaly beds. But the upper portion of the mass is a pore, light blue compact Limestone, including some beds vhich are crowded with shells and other marine animal remains.

This rock is well suited as a flux, and bams into a pure white lime.

The Limestone of the lower coal-measures consists of irregular thin beds, which are not continuous, usually found in two positions, the one below the so-called Limestone Ore and Coal, and the other below the Four-feet vein ; the former is found in Sheets* Hollow, but is not continued to the road where the Coal and Ore show their crops. The latter is absent in the neighborhood of the Anna Fur- nace, but makes its appearance beneath the Three-feet Coal, (the equivalent of the Four-feet), at and around Woodgrove. As we ap- proach the Two-and-a-half feet vein of Coal, the shales begin to show a marked proportion of diffused calcareous matter, and to contain knots of impure ochreous Limestone, which at some localities, as at Baker's, form one or more continuous bands of a shaly Limestone rock. About eighty feet higher than this, irregular courses of yel-

lowish limestone present themselves, and we now pass into an alter- nation of yellowish and hlnish Limestone, and varionsly colored shales and sandstones, in all, a thickness of limestone rock of ahont twenty feet. Above this, bat still beneath the Big Ooal, are two and sometimes three thin and very variable courses of shaly and ochreous Limestone, associated with the shelly and earthy ore beds of this division of the series.

AH the Limestones of the belt last spoken of, are of the argil- laceous kind, and all qf them contain carbonate of iron. In most of the layers, the latter ingredient is in snch large proportion as to impart an ochreons yellow color to the surface, after exposnre to the air. In many cases, the more thorough decomposition of the rock gives rise to a yellowish brown crumbling earthy mass, which is in fact a very meagre iron ore. The bioish Limestone, which, after being some time exposed to the weather, contracts bat little of this ochreons hoe, is generally the purest of these varieties of the rock, but either will be found to serve well as a flux in the reducing fur- nace.

Judging from some experiments which I made several years ago on limestones from the same belt, in another neighborhood, I think it probable that some of the bands above referred to, would furnish a valuable hydraulic lime.

Of the Fibk-Olay and WnKTSxoNE.

Beneath each of the Coal Seams, small as well as great, is found a stratum of Fire-clay. This, when pure, is a very intimate mixture of Alumina and Silica, (pure clay and sand,) and when of fine tex- ture, is an admirable material for the manufacture of firebricks and erueibUe, A compact variety of very even and fine texture occurs, associated with the Norris Ore and Coal, and has been extensively used in the manufacture of fire-brick at the Ferry. It has some- times a hardness approaching that of rock, and is known in the neighborhood by the title of Whetetone but a more appropriate name would be indurated Fire-day. The bricks made from it have been found of excellent quality.

The Norris bed has as yet been opened only along the face of the mountain, at the distance of more than a mile from the Fur- nace; but its dip must bring it down the side of the hill below the turnpike, within a third of a mile of the Furnace ; and I have already satisfied myself of its existence in this position.

Besides the Norris bed, other strata of Fire-day of available character may be resorted to when needed.

Wm. B. Boobbs.

June 28th, 1854.

The

Gravel And Cobble-Stone Deposits

or

Virginia And The Middle States.

On the Geavel and Cobble-stone Deposits op Yjst amiA AND THE Mn>DLE States.

Fbox Pbockkdihos or Bonoir Socnrr or NATinuL Hibvobt, 1879i

The surface deposits here referred to are extensively exposed in many parts of the belt which marks the junction of the older rocks with the tertiary and npper secondary formations in the Middle States. These deposits, especially in the great river volleys and adjoining slopes, as at Richmond and Washington, consist chiefly of layers of qnartz gravel, like the surface gravel of the adjoining pri- mary region, and of larger smoothly rolled masses derived from the silicious slates, qaartzites and sandstones of remoter tracts lying to the west and northwest, mingled and interstratified with ferraginous sands and clays, wMch impart to the mass a more or less reddish color.

In most localities, the larger pebbles are found in the upper part of the deposit, often strewing the surface thickly where the nner matter has been removed either by natural erosion or in the prog- ress of improvement) as may be seen at numerous exposures in and around Washington. In other cases, as at Alexandria and at Rich- mond, the oobble-stone deposit is usually overlaid by stratified sand and gravel of considerable thickness. It is from these sources that the cities of Richmond, Washington, Baltimore and Philadelphia, have been supplied with the paving materials at one time so gen- erally in use.

In a pile of such paving stones in Richmond, Yirginia, many years ago, I found a large pebble of compact vitreous sandstone, containing distinct impressions of SeolithuB linearu the well-known characteristic fossil of the Primal or Potsdam formation, having its nearest outcrop on the western side of the Blue Ridge. In subse- quent observations, especially those recently made in and around Richmond, Washington, and Georgetown, I have found that a con- siderable proportion of this pebbly or cobble-stone deposit consists of fragments of the harder silicious Paleozoic rocks and has therefore been derived from the Appalachian belt. Lideed, so common are the fossiliferons fragments, that an observer can hardly fail to discover them at any excavations where the coarser materials are exposed, as well as in the piles of cobble-stones in the neighborhood.

In the specimens exhibited to illustrate this paper, collected

chiefly at Washington and Richmond, it will he seen that the casts of Soolithns are very distinct and ahnndant. These masses are from two to six inches in diameter, hnt in some of the localities much larger specimens may he seen crowded with the fossil. Along with them are occasionaUy fonnd ronnded masses or cohhles of fossilifer- oas sandstone and of conglomerate, referahle to higher positions in the Appalachian series, ranging probahly to the carboniferous rocks. The absence from these deposits of fragments derived from the lime- stones, shales and argillaceous slates of the Appalachian belt, is readily accounted for by the comparative ease with which such ma- terials would be disintegrated by the mechanioal and chemical ac- tions concerned in their transportation and deposition, and the same explanation accounts for the fact that so few fragments of the gran- ites, schists, and gneissoid and hornblendio rooks of the wide inter- vening belt have been preserved in this formation, and that it re- tains little distinctly representing these rocks, except an abundance of quartz gravel and cobbles, derived from them.

The deposit in question extends at Washington over the entire plain on which the city is built, having an average elevation of seventy-five feet, and rising on the north to about one hundred feet above mean tide. Thence it spreads over the adjoining slopes, covering the high ground on which Columbian Oollege is situated, and the still higher hill of the Soldiers* Home, which is more than two hundred feet above tide. At the latter locality the roUed fragments have a less average size than at the lower level, though still often several inches in diameter. In the neighborhood of the Capitol, and in the railroad cutting near the Navy Yard, they are often as much as a foot in di- ameter, and a recent excavation near Georgetown, some forty feet above the creek, has brought to light masses of these transported rounded rocks of still greater dimensions, some of them large enon to be called boulders.

Although the surface formation in question shows itself in, and adjoining, the valleys of all the principid streams in the Middle States, the fragments of Paleozoic rocks have tbns far been observed only in the deposit as exposed in those river valleys which penetrate westward and northwestward as far as, or into, the Appalacnian belt. It is reserved for fhrther observation to ascertain whether they are wholly absent from the shorter valleys, and also to determine to what extent the general deposit is continued from valley to vaJley over the intermediate higher grounds.

Although from the facts thus far observed, it would seem that the transporting agency by which these deposits were accumulated was chieny or wholly operative in the lines of the river valleys, the great height to which, as before stated, the deposit reaches, shows that the relative level of the water, or probably ice, concerned in the transportation, must have been much above Uie water level as it now exists, and that the then actual river valleys were of correspondingly greater width. The distances over which the fragments of Appa- lachian rocks found in these surface deposits have ln carried, may be judged from the following facts.

The distance from Riohmond, in a straigbt line, to the nearest oatorop of the Primal or Potsdam sandstone west of the Bine Ridge, is abont eighty miles ; that following the conrse of the James River is one hundred and sixty miles ; the distance from Washington to the western side of the Bine Ridge in a straight line is abont forty miles ; that along the Potomac River between fifty and sixty miles.

What relation this deposit bears to the drift of the more north- em regions as to the manner and time of its prodnction, is a qnes> tion of great interest. The materials of the deposit are distinctly stratified, and the fragments, instead of being angidar, as so com- mon in the drift prope are well ronnded and smooth. Nor has there been thos far obsenred, any case of that striation of snrfaoe which is so f reqnently met with in the larger fragments of the north- em drift; tracing the formation, however, as it shows itself snoces- sively at Richmond, Washington, and other localities still farther northward, the stratification becomes less perfect, and the coarser materials are more scattered through the mass, and after crossing the Delaware the whole deposit cannot be distingnished from the material considered in that region as a modified drift.

Bpeonlating on the causes by which these deposits have been formed, it may, on the one hand, be imagined that during the glacial period the icy covering of the north and west prolonged itself in the valleys of the great rivers, as far sonth as the James, and even the Roanoke River, bringing down to the belt of land now marking the limit of tide water, debris from the Appalachian rocks, mingled with materials derived from the intervening region, and that the grinding and sorting action of the waters subsequently obliterated glaciu markings, and gave to the whole deposit the distribution and strati* fication which it now presents ; or, on the other hand, it may be conceived that the transporting force of the rivers themselves, swol- len and rapid as they must have been in the dosing ages of the gla- cial period, brought about the same results. But even, in this case, it is highly probable that glacial action had much to do with the original accumulation of the rocky debris on the flanks of the Blue Ridge, and in the Appalachian valleys beyond.

In the belt partially occupied by the surface deposit here referred to, there is exposed another group of strata, with which, at first view, the sanay and argillaceous layers of this formation might readily be confounded. These are the silicious, argillaceous and pebbly beds, which, underlying the tertiary in Virginia, and the well- marked cretaceous formation further north, have, in the latter re- gion, been regarded as belonging to the base of the cretaceous series of the Atlantic States. In Virginia the formation consists typically of a rather coarse, and sometimes pebbly sandstone, in which the grains of auartz and felspar are feebly cemented by kaolin, derived from the dfecomposition of the latter, and of argillaceous and sili- cious clays variously colored, and more or less chamd with vegeta- ble remains, either silicified, or in the condition of lignite. These constitute tiie group of beds designated in the Virginia geological reports as the Upper Secondary Sandstone, and referred by me long

ainoe (1842) to the upper part of the JnnaAo series, oorresponding probably to the Purliok beds of British geolots. From the Poto- mac northward, this group of deposits, as exposed in the deep rail* road cats between Washington and Baltimore, and on to Wilming- ton, is made np of variegated, soft, argillaoeons and siliciooa beds, which, from the preponderance of ferrnginons coloring towards the Delaware, has been called by Prof. Booth the red day formation. At a few points only, towards the bottom of the deposit, it brings to ▼lew a bed of the felspathic sand, or crumbling sandstone, above referred to. Traced transversely, it is seen to dip beneath the cre- taceous greensand at various points in New Jersey, Delaware and Maryland, but in Virginia disappears in its'eastward dip beneath the Eocene tertiary.

How far we may consider this group of sediments in Maryland, Delaware and New Jersey, as merely a continuation of the Virginia formation above described, can be determined only by further inves- tigation. But the discovery in them at Baltimore, by Prof. Tya<m, of stumps of cycads, would seem to bring them into near relation with the formation at Fredericksburg containing similar remains, and to favor their being referred, at least in part, to the horiaon of the upper Jurassic rooks. Possibly we may find here a passage- group analogous to the Wealden of British geologj. Whatever may be the result of further discovery, it would seem to be premature at this time to assume the whole of these deposits from the Potomac northward, as belonging to the cretaceous series.

Where the tertiary or the cretaceous rooks are present in this belt, there is, of course, no danger of confounding the superficial gravel and cobble-stone deposit with the formation just described, bat in their absence, which is usual in the river vaUeys, this deposit rests immediately on the broken and denuded surface of the sec- ondary, and by the intermixture of materials makes it more difficult to discriminate between them.

Excellent opportunities for observing the contact of the super- ficial deposit witn the denuded and much older formation below, are E resented in the neighborhood of Washington, among which may e specially mentioned the vertical cut at the extremity of 16th Street, at the base of the hill occupied by Oolumbian OoUege, and also the continuation of 14th Street, ascending the same hill. At the former locality the crumbling felspathic sandstone, or slightly adhering sand, is exposed to a height of about thirty-fire feet, with a very gentle eastern dip, and having the color, composition and diagonal bedding characteristic of the Fredericksburg and Aqnia Creek sandstone. The gravel and cobble-stone deposit lying upon it descends with the slope of the hill to the general plain below, resting at a somewhat steep angle against the denuded edges of the underlying beds.* From this and other localities, it becomes obvi- ous that the latter formation has been deeply and extensively de-

Since this was written (April, 1875), the excavation tnd grading have greatly changed the ezpoeure by covering up much of the lower depoeit.

nuded before and during tbe deposition of the snrfaoe strata, which lorm the chief subject of thiscommnnication.

At Biohmond this gravel and cobble-stone deposit presents itself at various heights from the river bank to the tops of tne hills, man- tling the irregularly denuded surface of the nnderlying formations; resting at one place on the Upper Miocene, at others, on the in- fusorial stratum, which lies at the base of the Miocene, or on the Eocene, or on the yet older deposit, referable probably to an upper secondary periud. The well-smoothed pebbles are chiefly of quartz- ite and silicious slates, including not a few which are marked with Scoiithus. In the Rappahannock valley, and between it and the Potomac, the formation may be seen resting directly either on the massive secondary sandstone, or on the looser deposit situated next above, or on the Eocene tertiary, which at some points occupies hol- lows in the denuded surface of tne sandstone.

Notes

From

Macfarlme'S Geological Railway Guide.

ViEonoA AND West Vibcikia." (Mixn Of Ruiwm ahd Stutose coBucno to 1B8R.)

Bt Piof. Williu B. Boou*. ImI of rt Geatoffkal Formiilion4 Founil in Viriuia and Wat Virgitu,

I'c.

Lovn Cu uom (U

90. QutiraHT.

lib. lUnwna. 19*. Xoonu.

(17, fC) JoiMM-Trluds.*

Nmn ndipled M

I b. Ldwbt OoU amp I ft OreKt Coqglainmta and Cuglo. CSil monp.

18 b. OitMibriu Bktlw. 18b Onenbrlar"' (Carb.Lli

13ft. MontvanuwTOri'.aftiid

KuoH nf N. T . Sorier chltll

is. Cftuuu

li h. gjilng. 1D' OMllllll'

1. OrUkan;

J: iats.r""'-

it, KUgftTft.

Siuiao.CAiiiwiA'

',4a. HndMO BlTsr. 4b. UtiM 4. Tranun

I 9 b CBiaitwtu. ' : S b. Potodwn Oronp.'

tSA

L VenaUnsBftiid-

X. Foiwnt. nil. IVanaat niL iVarfenl.

Haridlu

Pra-Maridifts.

SoUaBt.

WftUsftl. Hfttiul. JHaUnftL

VIRGINIA. Yaixst Branch of Baiiimobb Ain> Ohio Railboad.

Mile*.!

Uarpers Ferry.

( Altered Cambrian (b) or Archaean B, ( followed west by Cambrian, 2 b., 8 a.

Shenandoah.

Halltown.

Cambrian, 3 a., b.

Charlestown.

" 8 b., c.

Cameron.

u u

Wades ville.

Siluro-Cam., 4 a. and 4 b.

Stepheosons.

Silnro-CanL and Camb. 4 a. and 8 c

Winchester.

'

Kernstown. Stephens City. Vanclnae.' Middletown. Cedar Creek.

The road runs close to bonndary of

Cambrian 8 o., and Sil.-Oambrian, 4 a., of the belt lying east, oompoae laigely of 4 c.

Capon Road.

k

Strasbarg Junction.

Silaro-Cambrian, 4 a. and 4 b., on switch track.

Tom's Brook.

Cambrian, 8 b., o.

Maurertown.

U t(

Woodstock.

Ci C(

Edinbnrg.

it u

Mount Jackson.

Camb. and Silaro-Cam. 3 c. and 4 a.

New Market

(( hi

Broadway.

Linville.

Harrisonbnrg.*

Pleasant Valley.

Cambrian, 8 b., c.

Fort Defiance."

U ((

Stan nt on.

Camb. and Siloro-Cam. 8 e. and 4 a.

1. The term Jurasso-Cretaoeous is chosen to desisnuite the Upper Secondary sandstones of the Viiiniu reports and the associated aands and clays which in their prolongation, northeast through Maryland, Delaware and lew Jer- sey, are found to underlie the Crctaoeous green'Sand formation of those States, because the fossils found in the vicinity of Fredericksburg, &c., in Virginia, as well as near Baltimore, suggest the upper stafre of the Jurassic period ; while it is stated that the sands and clays oi this belt in New Jersey are refer- able to the base of the Cretaceous. The whole group would seem, in the main, to he one of transition, and it is probably best comparable to the European Wealden.

2. The name Jurasso-Triassic is preferred for the Mid-Secondary rocks of the Virrinia reports, as it is thought to correspond best vith the fossil indi- cations thus far furnished hy the several belts included in it Of these, the most western area is in part continuous with the so-called Triassic belt of Maryland and Pennsylvania, and in part with the ooal-beoring rocks of Dan Btver,North Carolina. The middle belt is in the line of proloncion of the Deep Kiver coal rocks of North Carolina ; and the eastern belt, indndin the Qrits and Coal Measures of Chesterfield, Henrico, &c., is topographically

Cbksapeaks and Ouio Railway.

MUm.

62

Richmond.

Atlee.

Hanover C. U, R. F. and P. June.

Noel.

Beaver Doin.

Buinpass. Frederick Hall.

Tolersville."

Lonisa. Gordonsville.

Lindsay. Cobham. Keswick. Charlottesville.

Ivy.

107 , Mechom River. 115 Greenwood.

Waynesboro.

Fishersville.

Stan n ton. Swoope.

North Mountain.

Croigsville.

Goshen." Millboro." Jackson River."

Covington."

221 Alleghany.

W. outcrop of Tertiary and Upper Me- sozoic, all resting on Arch. C. 19. Tertiary.

ti

Upper Mesozoic, Jnrasso-Cretaceous. 1. Archsean, C.

Gneiss and Mica Slates, with veins of

) Granite. 1. Arcbrean, A.

((

Mic. llornb. and Hydro. Mic. Slates,

( with Aurif. Quai-tz. The gold belt

1. Archffian, C. B. Argil. Mic. and Hydro. Mic. Slates, with patches of Slaty Limest. and Steatite, Epidotic, Chlor. and Sil. Grits and Slates of S. W. Mt. fol- lowed west by Gneissoid Sandstone.

1. Archaean, B.

Horn, and Chi. Gnei. Syen. 1. Arch., B, Bl. Ridge Epid. Chlor. Argil. Slates, &c., flanked W. by Camb. I, 2 b. Pots,

Cambrian, 8 a., aoining slates of 2 b.

) Sil. -Camb., 4 a. and 4 b. Edge of slate

I belt.

Camb. and Sil.-Cauib., 3 c. and 4 a.

It

i(

Devonian, 10 a., adjoining Silurian of

the Gapf 5 a., 5 b. to 8, inverted. Silurian, 7., Encrinal Marble. 8. Oris-

kany. Devonian, 10 a. and 10 b., between ridges of Silurian, 5 a. to 8. Devonian, 10 a., near 8 of Sideling Hill. Devonian, 10 a., west side of Rich Patch Anticlinal Silurian, 5 a. to 8. Devonian, 10 a. and 10 b., between southwest end of Warm Spring An- ticlinal, and northeast end of Peters Mountain. (Devonian, 10 to 12, enclosing, near tunnel, belt of Sub-Car. 13 a. Ves- ( pertine.

West ViBGiinA. Chbsapeaks and Ohio Railway. — Continued,

Miles.

White Sulphur

Springs. Ronceverte.

Fort Spring.

Alderson. Taloott.

Ilinton"

294 Qninnimont.

Hawk's Nest.

Cotton Hill.

Kanawha Falls

Coalbnrg.

Brownstown.

Charleston.

St. Albans.

Hurricane.

Milton.

Harbours ville.

Guyandotte.

Huntington.

j

Devon., 10 a. and 10 b. Spring issaes from 8. Ix>wer Sub-Carb.. 18 a. Vespertine. Upper Sub-Carb., 18 b. Umbral liine- ) stone. Upper Sub-Carb., 18 b. Umbral shale.

Upper Sub-Car., overlaid west by Con- glo. Coal group, 14 a.

Upper Sub. Carbon, shales, overlaid by Conglo. Coal group 14 a. The shales disappear west near Ba£falo Creek. CoDgl. Coal group, 14 a.

t(

Great Conglom., overlaid by Lower or main Coal group, 14 a. and 14 b. Main Coal group, 14 b.

Lower barren group, 14 b.

(4

without a oounterpart. The middle and eastern belts in Virjinm, and the western tract in >iorth Carolina, show a close agreement in their foasil flora, which in many particulars has a decidcdlv Jurassic character, and all three belts are connected bv certain species of fitliei-ia, Cundona, &c., held in oom- roon. Collectively tlieso beds reprenont most probably a group of deposits nuijOnfr through upper Triassic and Lower Jurassic time, and are in laige measure of a tmnaitional character.

8. In jrrounlnj the Lower Paleozoic formations, Sedcrewick's classification is used, incluainff as Cambrian and Sifuro- Cambrian, all the formations from the base of the Paleozoic to the top of the Trenton period (4 c), and as SUu- riin tho succeeding formations to the top of the Oriskany (8.) ; these oorrc- spondin: in limits to the Lower and Upper Silurian periods of the table.

4. The Middle Cambrian, or Auroral croun, occupying much of the surface of the Great Valley west of the Blue Ridire, ana exposeii in numerous onticlinals and faults in the mountain belt further west, is marked by a great preixmder- anee of mognesian limestones in the lower two-thirds of its mass, passing below in many cases into Arenaceous and Argillaceous limestones, and fol- lowed above by oolitic and by chertv and sandy beds, these latter giving place still hiher to the more purely Calcareous and Argillo-Calcareous strata ap- pertaining to the base of the Siiuro-Cambrian, Trenton or Motinal group.

YlBGINIiu

ViBonnA MiDLAin> Railway.

Miles.

[37

[60

[78

Alexandria*

Alex, and Fredbg.

Crossing. Springfield. Barkers. Fairfax. Clifton. Manassas. Bristoe. Nokesville. Catlett's. Warren ton June. Midland. Bealeton. Rappahannock. Brandj. Cnlpeper. MitohelPs. Rapid- Anne. Orange.

Madison.

GordonsviUe.

Lindsay.

Cobham.

Keswick.

Bhadwell.

Charlottesville.

Lynchburg Juno. Red HilL North Garden. Covesville. Faber's. Rookfish. Elmington. Lovingston. Arrington. Tje River. New Glasgow. Amherst. Molvor's. Barfords. Lynchburg.** Lncado.

Lawyers Road. Evington.

20. Quat. drift on denud. Upper Mesozoic, Jurasso-Cretaceons.

1. Arobsoan, 0.

A. " A.

A. Mes., 17-16. Jnras.-Tri.

It

(C

u u u u u

1. Archaean, B.

W. margin. S. margin.

ArgiL Hie and Hydro. Mio. Slates, with patches of Limestone and Stea- schist £. of 8. W. Mt, followed by Epidotio and Chloritic Quartzites and Slates of S. W. Mt. and thence W. by Gneissoid Grits.

1. Archiean, D.

From one and a half miles west of Charlottesville to near Lynchburg the prevailing rocks are Syenite, Granite, Protogine, Hie. and Chlor. Gneiss. Near base of S. W. Mt. are belts of Gneissoid sand and steasohist. Mic. and Hor. Slates and Trap.

1. Archffian. C. " B. C Micaceous and Argil. Slates, including patches of Limestone and Steatite, ( Epidotic and Chloritic Quartzitea

YomiNiA. MiDLAKD Bailwat. — Oontumed,

Miles

Otter River.

1. Archffian, G.

LynohB.

StaantoD Riyer.

Sycamore.

Ward's Springs.

Whittle's.

0g

Ohatbam.

Mesozoic, 17-16. Juraaso-Triassic, W. ) mar.

Dry Fork.

((

Fall Creek.

u

Danville.

1. Archaean, 0.

North Danville.

u

The frequent faults, invenions and repetitions of the bed in the Great VaUev, and the rarity of fossils in the Auroral rocksj have interfered with a precise demarcation of formations ; but there oan be little doubt, from fossil ana other evidence, that they cover the period of the formations 8 a., 8 b., 3 c, assigned to them in the Table. Hence, and as indicating the formations near as Veil as the localities, the designation 8 a. b. will be used for these rooks up to the top of the magnesian, without distinguishing between Calciferous and Quebec (or Levis), and 8 b. c, for the remaining strata up to the well defined hose of the Siluro-Cambrian, Trenton or MatinsI group, 4 a. b. and c

5. The Potsdam, or Primal group, includes in Virginia, where complete, besides the Potsdam proper, the femferouB shales next above, and the slates, shaly grits and couglomerates, below this formation. It is exposed in varvinff mass and completeness on the western slope and in the west flanking hills or the Blue Ridge throughout much of its length, often, by inversion, dippiiur to the southeast, in seeming conformity bencatli the older rocks of ue Blue Bidge, but often, also resting uncontormably upon or against them. These older rocks, comprising masses referable probably to Huronian and Laurentian ago, include also a gioup of highly altered beds, corresponding apparently to the copper-bearing or Keweenion series of northern Michigan, ana perhaps to the latoly described Dimetian rocks of Wales.

6. Tne letten A, B, C. D mark four rather distinct groups of Ardhnan rocks found in Virginia, oi whicli the first three may prolMibly be referred to the Laurentian Huronian and Montalban periods respectively, and the fourth to an intermediate stage — the Norian or Upper Laurentian.

7. This belt of Siluro-Cambrian slates extends continuously from the Po- tomac River to a point about ten miles south of Staunton, a distance of 140 miles, beyond which it becomes narrow and discontinuous. In the tract cor- responding to the interval from Strasburg to Harrisonburg, it encloses the complex synclinal of the Massanutton Mountains, consisting of massive rans of Silurian rocks 5 a.. 6 b., with some bands of 7 and a few traces of Devoman 10 a., all resting in the wide undulated trough of the slates. From Strasburg southwest, the railroad keeps generally a distance of from one half to one mile west of the ed of the slates, But sometimes impinges upon it, affording ready access to fossiliferous beds of 4 a., b. and c.

8. About 18 miles west-by-north fh)m this are the Bawley SpHngsand a few miles further the remarkable fissured rocks known as Moravian Town, both in Ponent 18. West-by-south, about 80 miles, are the Dora ooal mines, in Vespertine 18 a., of Narrowback Mountain — anthracite, faulted and crushed. The irrcsar fault which, with many interruptions, extends from near the Potomac River along the northwest edige of the Qreat Valley in the line of the

MAHA88A8 DiTIBION OV YlBOimA MmLANS BaJLVAT.

Mu6A.

Alexandria.

(As before.)

Manassas.

Mes., 17-16. Jara8.-Tria.

Gainesyille.

(i

Uajmarket.

Thoronghfare. Broad Kan.

C 1. Archasan, B, Slaty Qaartzlte, Epid.

i Ghlo. Argil, and Mio. Slates of Ball ( Ran and Pond Moantains.

Plains.

1. Archaean,

Marshall.

((

Rectortown.

Delaplane.

((

Markhain.

C(

Linden.

4t

Happy Creek.

ti

Front Royal.

Oambrian, 8 a. Caloifer.

River.

Sil.-Oamb. 4 a. and b. Tr. and Ut. 4 o.

Bnckton.

Hudson Riv.

Water Lick.

( Fort Mt. Synclinal, (5 n. and b.) ends ( near.

Strasbnrg.

" 4 a. and b. Tr. and Ut

Strasbarg Jane.

iC (i

Little North Mountain for about 120 mileB, is seen near these localities to bring the Siluro-Cambrian 4. of The Valley into juxtaposition with the Devonian 10. to 12.

9. About eight miles east of this are Weyer's and Madison's eaves, tntuated in a rid of steep dipping limestone, 8 a. b., near the South River.

10. In this part ot the gold belt are situated the old workings known as TindcrP, Boxley's, Baker's, Triple Fork and Walton's Mines.

11. This is a good point of departure for examining the rock structure of Panther Gap. 5 a. b., mostly inverted, and the wild passage of the NorUi River through the same formations at otrickler's Gap, The Goshen Pass." About 10 mues southwest are the Rockbridge Alum sprinff in 10 a. b.

12. About three mile:) north of this, on the Cow-j>asture Kivcr, is the Blow- ing Cave of Bath County, in an anticlinal of 8. Oriskany ; and twelve miles further north-by-west near the same river, is the noted intermitting stream called the £bbmg Spring, in a rid of 7 and 8, on east side of Tower (Tour) Hill, east of Warm Spring Axis. 12 miles southwest to Bath Alum Springs, in 10 a., and thence 5 miles to Warm Springs, 8 o-4 a.

18. Where traveraed by the Jackson River, this anticlinal shows itself as a great arch built up of the successive concentric bods of 6 a. b. c, and flanked by 7. and 8., followed by 10 a., and having a span, as measured by the highest sandstone bed, of about 8,800 feet. The main aroh, 6 a. Levant, or Medina, white sandstone, is regular and unbroken but the outer concentric belts, made up of the hard members of 5 b. c., are distorted and in part inverted on the west side of the axis, where by a slight fault the beds of 7. pass suddenly ftom a nearly vertical to a horizontal position. Towards the southwt, this axis opens, to form the Rich Patch Valley, bringing to view the Siluro-Cam- brian 4 a. , b. , c. , and still further southwest becomes the closed anticlinal known as the Potts Creek Mountain. Heavy beds of iron ore (Hematite) have been opened on both sides of this axis, as at Roaring Ron, Callie, Low Moor, and

Richmond, FBEDEBioKSBUBa and Potomac Bailboad.

Miles.

Washington

(Steamboat.) Qaantico. Richland.

BrookeB.

Potomac Ran.

Fredericksbarg.

Guinea. MUford. Penola. Ruther Glen. Janction. Taylors ville.

Ashland.

Richmond. Manchester Cross- ing. Temple's. Drewry's Bluff. Halfway.

Chester.

Port Walthall J. Petersburg. Keums. Stony Creek.

Jarratts.

Bellfield. Greensville Jan. Pleasant Plill Weldon.

Upper Mesozoio, 17-18. Jurasso-Creta.

" Patches of 19. Ter-

tiary on denuded sarfaoe.

i Falls. 19. Tertiary.

" Resting on Gneiss at

ti

Jurasso-Cretaoeons, 17-18.

S 20. Quaternary, gneiss coming to sor- ( face, Archroan, C. (Same as before.)

1 20. Quaternary, on decomposing ( Gneiss, Archaoan, C.

ti

)W. limit of Upp. Mesozoic and 19. Tertiary.

E. outcrop of Gne. Arch. C.

Gneiss higher up, on creek.

Gneiss short distance W. Tertiary dit-

19. Tertiary short distance E. it

i'. E. outcrop of Gneiss in Riv , 0.

Kayser'B noar Clifton Foiiore, associated with formation 8. OriBkany. The fo8il ore of 6 b. is also mined at several points.

14. The Anticlinal Valley, which includoa the grroup of thermals known as the Warm, Hot. Healing, &c., Sprinirs, closes up about ten miles northeast of this, and its axis subsides towards the southwest in broad Bi)ura whioh reach the river a few miles below Covington, in low ardies of 7. and 8., overUud by 10. The heated waters issue at numerous points throughout a distance of thirty miles, iVom Cambrian and Biluro-Oambrian rocks, 8 c, 4 a., usually inverted and often faulted along the west sie of the valley, the eastern bound- ary of which is formed by the masmve Warm Spring Mountain, 6 a.. 5 b., dip- ping east, while its western limit consists of a narrow, broken ridffe of the same formations in a veitioal or inverted position. Stages to Healing, Hot

Piedmont Aib Link Railboad.

Miles.

Ii

$K)

Richmond.

R. F. and P. Jnoct.

Powhatan.

Amelia 0. H.

Barkeville.

Keysville.

Roanoke.

Scottaburg.

Boston."

Barksdale.

Ringgold.

Danville.

Rnffin, N. 0.

(Same as before.)

4fc

W. edge of Mesozoio ooal field. 1. Archan, A.

i(

1. Archnan, 0.

4(

and Warm Springs, sevenilly 16, 19 and 22 miles. Near the flret is the Cas- cade (200 feet) of Falling Spring Creek, which, cutting through the west wall of the anticlinal, flows over a mass of calcareous tufa, deposited from the waters.

The anticlinal of Peters Mountain, rising a few miles northwest of Cov- higton and exposing at the tunnel 7. and 8., expands towards the southwest, until it opens out mto the valley of the Sweet Springs, containing another group of thermals of lower temperature than the preceding. This anticlinal, extending southwest, does not close uo, but pses into the great Peters Mountain and East Biver Mountain fault, whion for a distance of fifty miles brings the Cambrian in contact with the Vespertine and Umbral formations, Sub-Carb., 18 a., 18 b.

16. -The Upper Subcarboniferous, or Umbral shalct, here include a consid- erable thickness of brown and gray flaggy sandstone, the same which forms the hard rock of Swope's Knobs.

16. About 20 miles northwest of this point (bv canal or road) we enter the gorge which the James River traverses the Blue Ridge, where are exposed fine sections of Archnan rocks, A and B, and of the Cambrian, Primal 2 a., resting unconformablv on the western slope of the former, and occupying the flanking ridges, which adjoin the vallev. The Natural Bridge, the remnant of a former tunnel or cave m 8 a. b., is about 8 miles northwest ftt>m the upper end of the gap.

17. A few miles east of this, between Banister and Dan Rivers, is a small patch of Jurasso-Triassio rocks, 18-17., corresponding to the Farmville or nuddle belt, (see note 2). and oontiunin Eethena, &o.

18. This Qfposit, maae up laily of Diaton, lies near the base, bnt with- in the limits of the Miocene Tertiary. It contains occasional casts of Miocene shells, and is generally overlaid by beds of this formation, and rests cither upon or but little above the top of the Eocene. Having formcrW traced this deposit jfrom the Patuxent River m Maryland to the Meherrin in Virginia. I have lately found by an examination of the artesian borings at Fortress Monroe, that a similar aepodt exists in that region at the depth of 658 feet below the surface, overlaid b)r Miocene and Pliocene beds, and resting unon on Eocene deposit identical with that which underlies it at Richmond. We are thus assured of the great extension seaward of this deposit, and have the means of estimating the thickness of the Tertiary formations as far east as the mouth of the James River.

19. From this point, for manv miles towards the southwest, the railroad runs near .to and almost parallel with the broken syndinal, (about 26 miles long,) of which the lofty Catawba and Fort Lewis Mountains are the principal

Richmond, Tobk Riyeb akd Ohbsapbaks Railboao.

Miles.

Ricbmond.**

Fair Oaks.

Dispatch.

Summit.

Tanstall's. White House. Fish Hall. Sweet Hall. West Point.

(Same as before.)

At Richmond tunnel cuts Tert Infu- sorial bed, 19 b. Miocene.

In this interval both Lower and Upper 19. Tertiarj are accessible above tide leveL Eocene and Miocene.

In this interyal, only Upper 19. Tertiary is accessible above tide level. 19 b. Miocene.

parts. The fonnor, oomposed of loutheast dipping 4 a. b., &c., foitm the rarther or Dorthwest rim of the synolinal, and Mnding abruptly around at its northeast end, beoomes the Tinker Mountain, which closes the basin in that direction. A shorter and gentler bend at the southwest end, terminates in a &ult. The ooiresponding rocks of the southeast, or near side of the syn clinid, are only partially preserved in a narrow inverted ridge at either end, the remainder or this nm pf the synoUnal having been engulfed in the pro- longed fault, which, for many miles along the maigin of the basin, has brought the Siluro-Oambrian rocka (4 a. c.) of The Valley to abut agpnst, and oveinde the Devonian 10. to 12. and the Veaperitne 13 a., of which the Fort Lewis Mountain, the contra! mass of the synclinal, is mainly composed.

20. A few miles west-by-north of this is an area of Vespertine rooks, 18a., including one or more workable beds of oool, mined on Strouble's Bun and else* where. This area, onoe probably continuous with the Vespertine of Fort Lewis Mountain, is almost encompassed by faults. Further to the northwest, and separated from the above by a belt of Cambrian and Siluro-Cambrian rocks S c, 4 a., &0., the Vespertine beds of the southeast slope of the Brushy Mountain, contain a similar coal, mined on Toms Creek, all these seams being more or less affected br the neighboring faults. The dislocation whioh southeast of Brushy Mountain, brings Vespertine and Umbral in apposition with Siluro- Cambrian Matinal, is part of the great &ult which, wi£ some changes of di- rection and character, extends along the northwest of tlie Qreat Valley, from near the James River to the end of the Brushy Mountain, northeast of Abingdon, a distance of about 125 miles. At a distance of 28 miles in a north- west direction, is the sheet of water called Mountain Lake,* situated near the top of Salt Pond Mountiun, at a height of 4,000 feet above tide. Here tiio Potts and Johns Creek Mountains and the other ridges of 5 a. b. coalesce at their southwest termination, into a lofty rugged table-land, overlooking the New Biver, and oommanding wide views.

21. A few miles south, the Lick Mountain range divides The Valley for some miles into two, and in the southern of these belts, on the New Biver, below the mouth of Cripple Creek, are the Austin ville lead mines, in 8 b., near the Primal 2 b. of Poplar Camp Mountain, and about 16 miles distant from Wythe- ville.

82. From this point a short branch railroad leads north into the valley of the north fork of the Holston River, between Walker's Mountain, 5 a., &c., and Poor Valley ridge. Vespertine 18 c, iftc, which flanks the Clinch Moun- tain on the southeast side. Here, near SaltvUle, are the remarkable salt wells, which penetrate into a thick mass of rock-salt ; and in the same vicinity, ana at various points higher up the valley, for a distance of 20 miles, beds of gyp- sum have Doen opened and extensively wrought. These deposits are found near and in a line of fault, along which the Siluro-Cambrian 8 c. 4 a., of the southeast side of the valley, has been made to abut against and sometimes

Atla-NTio, Mississippi astd Ohio Railboad (Nobyolk akd Wsst-

Xkn, 1883).

Mow

Norfolk.

Suffolk.

Windsor.

ZunL

Ivor.

Wakefield.

Waverly.

Disputanta.

Petersburg.

Ohureh Road.

Ford's.

Wilson's.

Wellsville.

Blacks and Whites.

Nottoway 0. H.

BurkeyiUe.

Rice's.

Farmville.

Prospect.

Pamplin's.

Appomattox.

Concord.

Lynchburg.

Forest

Liberty.

Buford's.

Blue Ridgo.

Bonsack's.

Giflh's.

Roanoke.

Salem.**

Big Spring.

Shawsville.

Big TunneL

Ghristiansburg.'*

Oentral.

New River.

Dublin.

Martin's.

Max Meadows.

Wytheville."

Rural Retreat.

20. Quaternary, resting on Upper Ter- tiary 19 0. Pliocene. Up. 19. Tertiary and 19 b. Miocene.

a a

(C

{Lower 19. Tertiarj here probably above tide level

t E. margin of 19. Tertiary and U. 17-18 ( Mes. resting on Gneiss, 0. 1. Archesan, 0.

1. Archcean, A.

(i

((

t4

((

16. Mesozoic, 17-16. Jurasso-Triassio.

1. ArchflDan, A.

i(

1. Archffian, B. 1. ArchfeaDr A.

(t

2-4. Garobrian, 3 a. Oalciferous.

3a.b.

it (i (( (t (( t( It tt

(C

ti

it

and Siluro-Cambrian. 3 c. and 4 a. Oh. and Tr.

3 b. c.

it

tc

tt it tt

!

Fault of Draper's Mt. Silurian and De- vonian against Sub-Carbonif. 2-4. Cambrian, 3 b. c.

it

ATLAimO, Ml08I80IPPI AND OhiO BaXLBOAD (NoSFOLK AZTD WX8T-

BBN, 1883). — Continued,

Hum.

Marion.

Glade Spring.*' Abingdon. Bristol

2-4. Cambrian and Sil.-Cam. 8 c, 4 a.

a u

u

Oonttiiaed u EmI Tennessee, YirgInU sad Oeoivls Ksflrosd.

Skaboabd akb Roanokk Railroad.

Miles.

Portsmouth.

20. Qnat. on 19 Ter. and 19 o. Pliocene.

Suffolk.

20. Qnat on 19 b. Miocene.

OarrsviUe.

4(

Franklin.

Nottoway.

t(

Newsom's.

t(

Boykius.

(1

Margaretsville.

tc

SealKMird.

u

Gary's.

"

Weldon.

Outcrop of Gneiss.

over-ride the Umbral IS b., which, with the Vespertine 18 a. of the Poor Val- ley Mountain, form a belt on the northwest side of the Talley. Both deposits are most probably referable to the Hubcarboniferous period. The fault hero spoken or extencb, with some local changes of character and direction, in a west-by-southwost course, fh>m a point in Giles county to the Tennessee line, a distance of 126 miles, and is prolonged many miles into Tennessee.

WlIXlAM B. BOOKRS.

28. So few details have been published on the geology of Viigixda, that no chapter in this volume will be more welcome to geologists than this, which has Deen wholly and very careftUly prepared by Professor William B. Koffers, late State Geologist of Virginia. J. M.

Wasbriotom and Ohio Baiuioad.

Miles.

Alexandria.

(Same as before.)

GarlinV

FaU's Church.

1. Archfldan, C.

Vienna.

1. Archffian, A.

Hunter's.

it

Thornton.

1. ArchiBan, B.

Hemdon.

Mesozoic, 17-16. Jarasso-Triasslc.

Guilford.

U ii

Farmwell.

u

Leesharg.

" W. mar. Cong.

Clark's Gap.

1. Archaean, 6.

Hamilton.

ti

Purcellville.

C(

Round Hill.

tc

Artesian Boeings

Ax

Fortress Monroe.

Infusobial Deposit of Virginia in the Fort Monroe

Artesian Well.

Fbox Th YiBocaAS, Ootobsb, 18S2.

In 1867 Gen. A. A. HurophreyB, tben Chief of tLe U, 8. Engi- neers, wrote me, asking respecting the probable or coqjectaral verti- cal position of water-bearing strata at Fort Monroe; and again wrote in July, 1869, when this well, begun in 1864, had reached a depth of about 600 feet, and sent me portions of the borings and the contained fossils from different depths. In September of 1869, Gen. Humphreys, in response to my request, again sent an account of the further progress in boring the well to a depth 907 feet, and also samples of the borings down to that depth. That letter stated that at a depth of 699 feet very saline water flowed from the mouth of the well for several days.

The materials of this section of 907 feet, nearly all of it below the level of Chesapeake Bay, were studied by me with great care as probably revealing the concealed geological structure of The Penin- sula. In these were found a number of sharks teeth identical with those discovered by me long since in the section in Amblers Hill, Richmond.

In the Eocene and above it, at a depth of about 558 feet in this well, a stratum of Infusorial Earth was reached, which, on critical examination by the able microscopist, Samuel Wells, Esq., yielded abundance of Diatoms, nearly all identical with those of the Rich- mond beds.

I have thence obtained what I think is proof of the presence of Cretaceous between this Eocene and what has the appearance of Jurasso-Cretaceous of the lower part of the borings, and the evi- dence of the great extension seaward of that deposit, and also the means of estimating the thickness of the Tertiary formation as far east as the month of James River.*

Artesian Boring% at Fortress Monroe Va., beginning at 151 fl. below the level of the Parade. — Materials examined and notes made by me on their fossils, &c., in 1876.

See Macfarlane's Geological Railway Guide, page 182, note 18. In addi- tion to intrinsic value of this contribution to our knotrledge of the extent of the Tertiary fonnation in Virginia by Prof. Roen, it has a special interest, not only as the last published creological investigatioD made by him, but as being in the samejida in which ne began his labors half a century before. — £d.

At

161'. Fine yellowish gray sand, with fragments of shells.

158'. Buff argillaoeoQS marl.

160'. Fragments of Tarritella and Peotens in gray marl mostly.

Conmiinated shells. 164' 6". Fragments of Turritella and Peotens in gray marl mostly.

Comminuted shells. 166' 10". More sandy than last. Fragments of Area. 1 68' 10". Dittowith Balanidao, &o. 170' 10". Gray sand with Area, &o. 192'. Oreenish gray. Sandy. Tarrftella. 194'. Lighter gray. Sandy. Tarritella. 197'. More clayey than 194'. 202'. Ditto.— Fragments of Venns, &o. 204'. Ditto, ditto.

208'. Ditto, ditto.— With Perna, Venns, Ac.

890'. Tenaceous gray clay, with shelly matter* 400'. Gray sandy clay, Artemce, Venus, Ac. 430'. Yellowish sandy clay. 555'. (1). Light clay, gray brown in color. Minute shells since

found to be Foraminifer®. 558'. (2). Infusorial earth containing :

Fragments of Pinnnlaria, peregrinat

Gallionella sulcata.

Ooscinodiscus apiculatus, abundant

Coscinodiscus gigas.

Trioeratium.

Dictyocha crux.

Actinoptychus biternarins.

Navioula.

Actinocyclus bioctonarius.

— Besides those in the list (published elsewhere)

kindly made by Samuel Wells, Esq., from some of

the borings sent him by me. 670'. Miocene down to about this depth. 674'. (2). Cetacean bone.

577'. (8). Concretions of sand, marl and shells, composed of coarse sand, little pieces of milky and smoky and sometimes rose quartz, often sub-angular.

Between 577' and 683' is probably the base of the Mio- cene. Between 580' and 590shark8 teeth, Galeocerda lat- eralis. 683'. (4). Sandy clay, brownish.

690'. (5). Very sandy clay ; about 5 per cent coarse sand. Speci- mens of shark's teeth. 604'. Brownish gray sandy clay. 628'. Ditto. (Less sand.)

640'. Greenish gray, sandy. 670'. Lightest gray clay.

699'. Brownish gray sandy clay; less sand than 604'; same indeed as 628'.

At

907'.

Brownish gray sandy clay, — same as 604',

Gray sandy clay.

Very coarse sand.

Conglomerate of clay, sand and pebbles.

Rather fine clay with a little sand.

Ditto, ditto.

Coarse sandy clay, brownish or reddbh blotches. Clay embedding fragments of granite. Gray clay with occasional fragments of coarse sand.

Ditto, ditto.

Clay and sand in layers with some coarse pebbles and red- dish blotches. Reddish mottled clay with quartz pebbles. Ditto, — with coarse sand. Ditto, ditto.

Total depth of boring below parade ground.

Ths Fasnls.

In 1875, the organic remains of the borings were submitted by me to Samuel WeUs, Esq., and in July of that year I received the following reply : In comparing this material with the Richmond deposit, of which I have several slides from Shockoe Hill and Am- blers Hill, and for which purpose I have examined Ehrenbergs Atlas, I find it deficient in the Melosira (sulcata principally), and in the many-rayed Actinocyclus, both of which are common in Rich- mond. It is also wanting in the Heliopelta and Craspedodiscns which abound in the Nottingham and (so-called) Bermuda deposits. I do not- think that it is identical with either. I cannot learn that these deposits have been examined with reference to a comparison of dif- ferent locations and depths and it would be interesting if the whole of the Richmond and the Maryland deposits could be so compared.*

In October, 1876, Mr. Wells wrote :

I enclose a revised list of Diatoms found and identified in the Fortress Monroe material, 40 in all, of which 29 have been pre- viously found in the Richmond deposit, leaving only 11 not so re- corded, thus establishing the substantial identity of this material with that underlying Richmond."

Rerised list of IHatofM from borings from artesian well at For- tress Monroe. — By Samuel Wells, Esq., Oct. 81, 1876.

Va.

Acdnocydus monilifonnis.

Ral&ii. Va. Actinoptychiu undulatus. Ya. Asterolampra Grevillii, fragm. Coednodisctis apiculatua. Va.

diBciger. Va.

ooncavuA. Vo.

excavatua.

heteroporuB.

genuniferl

Bictyocha triacantba.

istaurodon. Va.

Ponticuluii.

speculum. Va. Euodia Barbadenais. Eupodiscufl Aigus, fhm. Ooniothecium odontella. Va. Melosira sulcata. Va. Odontodiscus Uranus. Va. Podoaiiu macolata.

CoMnnodiflcns lineatus. Va.

minor. Va.

nuuvinatiis. Va.

ommuJanthus. Va.

penonbtufl. Va.

radiatuB. Va.

radiolatus. Va.

etriatua. Va.

velatus. Va. Crapedodiacus CoBcinoducus. Va.

Pyxidioula <*nieiata. Va.

Actinocyolua. Va. StephanopTxia apiculata.

Biadema. Va. Bynedra Ulna. Va. SvBtephania Corona. Va. Triceratiuin Marylandicmn. Va.

aontum.

amblyooeroa. Va. XoDtliioprxis oblonga. Va.

The following is from Prof. Rogers' reply to the above :

117 MAKLBOBonon Street, Boston, NoveTDber 18, 1876.

" Deab Mb. Wells : I thank you for the trouble yon have taken in sending me the list with explanations, and while I am gratified to find that yoar examination confirms my early impression of the sabstantial identity of this deposit with that underlying Richmond, I am sure that you have earned the thanks of all who are interested in our Tertiary Geology for the skill and care with which you have studied the forms of this new and peculiar locality.''

Glossabt of Geological and other Scientific Tebms.*

Fsov Ltslls Pbimoifub or Osoumt.

Alluvium. — Earth, sand, gravel, stones, and other transported mat- ter which has been washed awaj and thrown down hy rivers, floods, or other causes, npon land not permanently submerged beneath the waters of lakes or seas.

Amorphous. — Bodies devoid of regular form.

Amygdaloid. — One of the forms of the Trap-rocks, in which agates and simple minerals appear to be scattered like almonds in a cake.

Analeime. — A simple mineral of the Zeolite family, also called Oa- bizite, of frequent occurrence in the Trap-rocks.

Anticlinal Axis. — If a range of hills, or a valley, be composed of strata, which on the two sides dip in opposite directions, the imaginary line that lies between them, towards which the strata on each side rise, is called the anticlinal axis. In a row of houses with steep roofs facing the south, the slates represent inclined strata dipping north and south, and the ridge is an east and west anticlinal axis.

Arenaceous. — Sandy.

Argillaceous. — Clayey, composed of clay.

Arragonite. — A simple mineral, a variety of carbonate of lime, so called from having been first found in Arragon, in Spain.

Augiie. — A simple mineral of a dark green or black colour, which forms a constituent part of many varieties of volcanic rocks.

Basalt. — One of the most common varieties of the Trap-rocks. It is a dark green or black stone, composed of augite and felspar, very compact in texture, and of considerable hardness, often found in regular pillars of three or more sides, csJled basaltic columns. Remarkable examples of this kind are seen at the Giant's Oauseway, in Ireland, and at FingaVs Cave, in Staffa, one of the Hebrides. The term is used by Pliny, and is said to come from hasal an iSlthiopian word signifying iron. The rock often contains much iron.

" J!aw" of Paris, ''Basin'' of London.— Depositee ling in a hol-

Appended to Virginia Geological Survey Report for 1840.

Y38

low or trongh, formed of older rocks, sometimes used in geol- ogy almost synonymoaslj with "formations," to express the deposites lying in a certain cavity or depression in older rocks.

Belemnite, — An extinct genus of the order of mollnscons animals called Cephalopoda, having a long, straight and chambered coni- cal shell.

Bitumen. — Mineral pitch, of which the tar-like substance which is often seen to ooze oat of the Newcastle coal when on the fire, and which makes it cake, is a good example.

Bituminotu Shale, — An argillaceous shale, much impregnated with bitumen, which is very common in the coal measures.

Blende, — metallic ore, a compound of the metal zinc with sul- phur. It is often foond in brown shining? crystals, hence its name among the (German miners, from the word blenden, to dazzle.

Botryaidal, — Besembling a bunch of grapes.

Bowlden, — A provincial term for large rounded blocks of stone lying on the surface of the ground, or sometimes imbedded in loose soil, different in composition from the rocks in their vicinity, and which have been therefore transported from a dis- tance.

Breccia, — A rock composed of angular fragments connected together by lime or other mineral substance. An Italian term.

Calc Sinter, — A (rerman name for the deposites from springs hold- ing carbonate of lime in solution — petrifying springs.

Calcareous ioel;.— Limestone.

Calcareous Spar. — Crystallized carbonate of lime.

Calcedony, — A siliceous simple mineral, uncryatallized. Agates are partly composed of calcedony.

Carbon, — An uudecomposed inflammable substance, one of the sim- ple elementary bodies. Charcoal is almost entirely composed of it.

Carbonate of Lime, — Lime combines with great avidity with car- bonic acid, a gaseous acid only obtained fluid when united with water, — and aU combinations of it with other substances are called Carbonates. All limestones are carbonates of lime, and quick lime is obtained by driving off the carbonic acid by heat.

Carbonic Acid Gas. — A natural gas which often issues from the ground, especially in volcanic countries.

Carboniferous, — A term usually applied, in a technical sense, to an ancient group of secondary strata, but any bed containing coal may be said to be carboniferous.

Cephalopoda, — A class of molluscous animals, having their organs of motion arranged round their head.

Cetacea, — An order of vertebrated mammiferous animals inhabiting tiie sea. The whale, dolphin, and narwal, are examples.

Chalk, — A white earthy limestone, the uppermost of the secondary series of strata.

Chert, — A siliceous mineral, nearly aUied to calcedony and flint, but

less homogeneous and simple in texture. A gradual passage from chert to limestone is not uncommon,

Chhritie Sand. — Sand coloured green by an admixture of the simple mineral chlorite.

Clinkataney called als)0 Phonolite a felspathio rock of the Trap fam- ily, usually fissile. It is sonorous when struck with a hammer, whence its name.

Coal Formation. — This term is generally understood to mean the same as the Coal Measures. There are, however, ooal forma- tions " in all the geological periods, wherever any of the varie- ties of ooal form a principal constituent part of a group of strata.

CoTformable, — When tbe planes of one set of strata are generally parallel to those of another set which are in contact, they are said to be conformable.

Conglomerate or Rounded water- worn fragments of rock or pebbles, cemented together by another mineral sub- stance, which may be of a siliceous, calcareous, or argillaceous nature.

Contfera. — An order of plants which, like the fir and pine, bear cones or tops, in which the seeds are contained.

Crag, — A provincial name in Norfolk and Sufiolk for a deposite, usually of gravel, belonging to the Older Pliocene period.

Cretaceous. — Belonging to chalk.

Crop Out, — A miner or mineral surveyor's term to express the rising up or exposure at the surface of a stratum or series of strata.

Crustacea. — Animals having a shelly coating or crust, which they cast periodically. CrabH, shrimps and lobsters are examples.

Cryptogamie. — A name applied to a class of plants, such as fema, mosses, sea-weeds, and fungi, in which the fructification or organs of reproduction are concealed.

Crystalline. — The internal texture which regular crystals exhibit when broken, or a confused assemblage of ill-defined crystals. Loaf sugar and statuary marble have a crystalline texture. Sugar candy and calcareous spar are crystallized.

Debacle. — A great rush of waters, which, breaking down all oppos- ing barriers, carries forward the broken fragments of rocks, and spreads them in its course.

Delta. — When a great river, before it enters the sea, divides in- to separate streams, they often diverge and form two sides of a triangle, the sea being the base* The land included by the three lines, and which is invariably alluvial, was first called, in the case of the Nile, a delta, from its resemblance to the letter of the Greek alphabet which goes by that name. Geologists apply the term to alluvial land formed by a river at its mouth, without reference to its precise shape.

Denudation. — The carrying away by tbe action of running water of a portion of the solid materials of the land, by which inferior roks are laid bare.

Ho

Dykes, — When a mass of the nnstratified or igneons rocks, such as Granite, Trap, and Lava, appears as if injected into a great rent in the stratified rocks, catting across the strata, it forms a dyke ; and as they are sometimes seen running along the ground, and projecting, like a wall, from the softer strata on both sides of them having wasted away, they are called in the north of Eng- land and in Scotland the provincial name for wail. It is not easy to draw the line between dykes and veins. The former are generally of larger dimensions, and have their sides parallel for considerable distances; while veins have generally many ramifications, and these often thin away into slender threads.

Diluvium, — Those aconmnlations of gravel and loose materials which, by some geologists, are said to have been produced by the action of a dUuvian wave or deluge sweeping over tlie sur- face of the earth.

Dip, — When a stratum does not lie horizontally, but is inclined, the point of the compass towards which it sinks is called the dip of the stratum, and the angle it makes with the horizon is called the angle or dip of inclination.

DoUrite, — One of the varieties of the Trap rocks, composed of An- gite and Felspar.

Dolomite, — A crystalline limestone, containing magnesia as a con- stituent part. Named after the French geologist Dolomieu.

Dunes. — Low hills of blown sand that skirt the shores of Holland, England, Spain, and other countries.

Eocene, — The great Tertiary era is divided into four periods, the first of which is called Eocene indicating that in the beds of this division, we see the first traces or dawn of the present order of things. The class of fossils most serviceable in determining the relations of the existing to the extinct species, are shells, and it is between these, more particularly, that the comparison has been made. Out of about 1,200 shells discovered in Europe in this lower division of the Tertiary rocks, 88 only are identical with species known to be living. This small propor- tion (about 8 per cent.) varies a little, of course, with the de- posites of different regions ; and the deposites of this formation, like those of any other, are characterized less by the precise pro- portion of their extinct fossils, than by possessing a number of shells peculiar to the particular era, and found in no other Ter- tiary groups.

Estuaries. — Inlets of the land, which are entered both by rivers and the tides of the sea. Thus we have the Estuaries of the Thames, Severn, Tay, &c.

Faulty in the language of miners, is the sudden interruption of the continuity of strata in the same plane, accompaniea by a crack or fissure varying in width from a mere line to several feet, which is generally filled with broken stone, clay, &c.

Felspar, — A simple mineral, which, next to Quartz, constitutes the

Y41

chief material of rooks. The white angular portions in Granite

are Felspar. Ferruginous. — Any thing containing iron. Formation, — A group, whether of alluvial deposites, sedimentary

strata, or igneous rocks, referred to a common origin or period. FomU, — All minerals used to he called fossils, hut geologists now use

the word only to express the remains of animak and plants

found huried in the earth.

Galena, — metallic ore, a compound of lead and sulphur. It has often the appearance of highly polished lead.

Oa/met — simple minerid, generally of a deep red colour, crystal- lized ; most commonly met with in Mica sli hut also in granite and other igneous rocks.

Gault — A provincial name in the east of England for a series of heds of clay and marl, the geological position of which is he- tween the upper and lower greensand.

Onem. — A stratitied primary rock, composed of the same materials as Granite, hut having usually a larger proportion of Mica, and a laminated texture. The word is a German miner's term.

Granite, — An unstratified or igneous rock, generally found inferior to or associated with the oldest of the stratified rocks, and sometimes penetrating them in the form of dykes and veins. It is usually composed of three simple minerals, Felspar, Quartz, and Mica and derives its name from having a coarse granular structure.

Graywaeke, — Grauuxieie, a German name, generally adopted hy geologists for the lowest members of the secondary strata. The rock is very often of a gray colour, hence the name grau, being German for gray, and waeie being a provincial miner's term.

Greensand. — Beds of sand, sandstone, limestone, belonging to the Cretaceous period. The name is given to these beds because they often, but not always, contain an abundance of green earth or chlorite scattered through the substance of the sandstone, limestone, &c.

Greenstone, — A variety of Trap, composed of Hornblende and Fel- spar.

Grit. — A provincial name for a coarse grained sandstone.

Gypsum. — A mineral composed of lime and sulphuric acid, hence called also sulphate of lime. Plaster and stucco are obtained by exposing gypsum to a strong heat. It is found so abundantly near raris, that Paris plaster is a common term in this country for the white powder of which casts are made. The term is used by Pliny for a stone used for the same purposes by the ancients. The derivation is unknown.

HornbUnde, — A simple mineral of a dark green or black colour, which enters largely into the composition of several varieties of the Trap rocks.

Homstone, — A siliceous mineral substance sometimes approaching

nearly to flint, or common Qnartz. It hasaconohoidal fracture, and is infusible, which distingaiehes it from compact Fdspar.

Jura Lime$t(me. — The limestones belonging to the oolitic gronp, eon- stitate the chief part of the moantains of the Jura, between France and Switzerland, and hence the geologists of the conti- nent have given the name to the group.

Lamina. — Latin for plates ; used in geology for the smaller layers of which a stratum is frequently composed.

Lava. — The stone which flows in a melted state from a volcano.

Lias, — A provincial name, adopted in soientiflc language, for a par- ticular kind of limestone, which, being characterized together with its associated beds, by peculiar fossils, forms a particular group of the secondary strata.

Lignite, — Wood converted into a kind of coal.

Lithohgical, — A term expressing the stony struotnre or character of a mineral mass. We speak of the lithologieal character of a stratum as distinguished from its zoological character.

Littoral, — Belonging to the shore.

Loam, — A mixture of sand and day.

Madrepore, — A genus of corals, bat generally applied to all the cor- als distinguished by superficial star-shaped cavities. There are several fossil species.

Mammillary, — A surface which is studded over with rounded pro- jections.

Mammoth, — An extinct species of the elephant, of which the fossil bones are frequently met with in various countries. The name is of Tartar origin, and is used in Siberia for animals that bur- row under ground.

Marl.— A. mixture of clay and lime; usually sofb, but sometimes hard, in which case it is called indurated mnrl.

Mastodon. — A genus of fossil extinct quadrupeds allied to the ele- phant. So called from the form of the hind teeth or grinders, which have their surface covered with conical mammillary crests.

Matrix, — If a simple mineral or shell, in place of being detached, be still fixed in a portion of rock, it is said to be in its matrix. Matrix womb.

Meehanieal Origin Rock of. — Rocks composed of sand, pebbles, or fragments, are so called, to distinguish them from those of a uniform crystalline textare, which are of chemical origin.

Mica. — A simple mineral, having a shining silvery surface, and ca- pable of being split into very thin elastic leaves or scales. It is often called talc in common life, but mineralogists apply the term talc to a diflfcrent mineral. The brilliant scales in granite are mica.

Mica-Slate, Mica- Schist Micticeous Sehistvs. — One of the lowest of the stratified rocks, belonging to the hypngeno or primarv

Y43

class, whioli is characterized by being composed of a large pro- portion of mica, united with quartz.

Mioesne. — This is the period next sacceeding the eocene, and em- braces a krger share of recent or living species among the or- ganic remains. Out of 1,021 shells in Europe, 176 onlj belong to animals now living, making the proportion of the recent species about 18 per cent.

Molhuea Molluscous Animals. — Animals, such as shell-fish, which, being devoid of bones, have soft bodies.

Mountain Limestone, — series of limestone strata, of which the geological position is immediately below the coal-measures, and with which they also sometimes alternate.

Muriate of Soda, —The scientific name for common culinary salt, because it is composed of muriatic acid and the alkali soda.

New Red Sandetone. — A series of sandy, argillaceous, and often cal- careous strata, the predominant colour of which is brick-red, but containing portions which are of a greenish grey. These occur often in spots and stripes, so that the series has some- times been called the variegated sandstone. The European formation so called lies in a geological position immediately above the coal measures.

Nodule. — A rounded irregular shaped lump or mass.

Old Bed Sandetone. — A stratified rook belonging to the Carbonif- erous group (of Europe).

Oolite Oolitic. — A limestone, so named because it is compose<l of rounded particles, like the roe or eggs of a fish. The name is also applied to a large group of strata, characterized by pecul- iar fossils, because limestone of this kind occurs in this group in England, France, &c.

Organic Remain*, — The remains of animals and plants {organized bodies) found in a fossil state.

Orthoeerata or Orthoeera. — An extinct genus of the order of Mol- luscous animals, called Cephalopoda, that inhabited a long chambered conical shell, like a straight horn.

Outlieri, — When a portion of a stratum occurs at some distance, detached from the general mass of the formation to which it belongs, some practical mineral surveyors call it an outlier, and the term is adopted in geological language.

Oxide. — The combination of a metal with oxygen ; rust is oxide of iron.

Oxygen. — One of the constituent parts of the air of the atmosphere ; that part which supports life. For a further explanation of the word, consult elementary works on chemistry.

Pelagian, Pelagic. — Belonging to the deep sea.

Petroleum. — A liquid mineral pitch, so called because it is seen to

ooze like oil out of the rock. PieoUte. — A stone possessing a structure like an agglutination of peaa.

Pit Coal. — Ordinary coal ; called so beoaoac it is obtaiDcd bj sink- ing pits in the gronnd.

PUch Stone, — A rock of a uniform teztare, belonging to the nn- stratified and volcanic classes, which has an unctuoos appear- ance like indarated pitch.

Flioeene. — This is founded upon the existence, in the beds which it embraces, of a greater number of recent than extinct species. The pliocene rocks are referred to two periods, the Older Pli<H ocene and Newer PDocene. In the newer pliocene, the num- ber of extinct species is extremely small.

Plutonic Boek$. — Granite, porphyry, and other igneous rocks, sap- posed to have consolidated from a melted state at a great depth from the surface.

Porphyry, — An unstratified or igneous rock.. The term is as old as the time of Pliny, and was applied to a red rock with small angular white bodies diffused through it, which are crystallized felspar, brought from Egypt. The term is hence implied to every species of unstratified rock in which detached crystals of felspar are diffused through a base of other mineral composition.

Preeipitato. — Substances which having been dissolved in a fluid, are separated from it by combining chemically and forming a solid which falls to the bottom of the fluid. This process is the opposite to that of chemical solution.

Produeta, — An extinct genus of fossil bivalve shells, occurring only in the older secondary rocks. It is closely allied to the living genus Terebratula.

Pyrites, (Iron.) — A compound of sulphur and iron, found usually in yellow shining crystals like brass, and in almost every rock stratified and unstratified. The shining metallic bodies, so often seen in common roofing slate, are a familiar example of the mineral.

Quartz,— K German provincial term, universally adopted in scien- tific language, for a simple mineral composed of pure silex, or earth of flints : rock-crystal is an example.

Sandstone. — Any stone which is composed of an agglutination of grains of sand, whether calcareous, siliceous, or of any other mineral nature.

Saurian, — Any animal belonging to the lizard tribe.

Schist, — Synonymous with slate.

Seams. — Thin layers which separate two strata of greater magnitude.

Secondary Strata, — An extensive series of the stratified rocks which compose the crust of the globe, with certaiu characters in com- mon, which distinguish them from another series below tliem, called primary and from a third series above them called ter- tiary.

Sedimentary Rochs are those which have been formed by their ma- terials Imving been thrown down from a state of suspension or solution in water.

SeUniU.~-€rj8teSl\zitA gjpanni, or BulptuM of lime — a dmple mio-

erd. Strpentine.—A rock naaslly containioff mnofa magneBian eartb, for

the moet part nnstrathied, bat BometimM appeariDg to be on

altered or metamorphio stratified rock. Its name is derived

from fraqnentlf preaentiDg oontraata of colour, like the skin of

some serpoDta. Shale. — A provincial term, adopted h; geologials to oipresa an io-

ilnrated slaty olsj. Shell Marl. — A deposite of claj, peat, and other substances mixed

with shells, which collects at the bottom of lakes. Shingle. — The loose and oompletelf waler-wom graTel on the sea-

Silex. — The name of one of thopare earths, being the Latin word for Jlint, which is whollj composed of that earth. French geologists bare spplled it as a generic name for all minerals composed eniiire]; of that earth, of which there are many of difiereat external forms.

Silieemu.-Oi or belonging to the earth of flint. A sillceoua rock is one mainlj composed ofsilex,

SUl.'— The more comminuted sand, claj, and earth, which is trans- ported by mnning water. It is often aoonmnlated by cnrrenta in banks. Thus the month of a river is silted up when its en- tranoe into the sea is impeded bj such aeon m illation of loose materials.

Simple Jftnerat— Individual mineral substances, as distinpiiiBhed fh>m the rocks, which last are nsnally an aggregation of simple minerals. They are not simple in regard to their natore, for, when sobjerted to chemical analysis, they are foand to consist of a variety of ditFerent substances. Pyrites is a simple mineral in the sense we use the term, bnt it is a chemical componnd of snlphur and iron.

Stalactite. — When water holding lime in solution deposites it as it drops from the roof of a cavern, long rods of stone hang dowD like icicles, and these are called ilalactitre.

Stalagmite. — When water holding lime in solntion drops on tbe floor of a cavern, the water evaporating leaves a crust com- posed of layers of limestone: such a crust is called ttalagmite.

Stilbite. — A crystalltxed rimple mineral, nsnally white, one of tbo Zeolite family, frequently ioclnded in the mass of the Trap

Strata, 5(ra(ffl.— When several rocks lie like the leaves of a book,

one npon another, each individual forms a ttratum; strata is

the plnral of the word. Strike. — The direction or line of hearing of strata, wlil<-)i iAv. .1

at right angles to their prevailing dip. Sj/enite. — A kind of granite, so called becaase it was hroiiiii fi''.iiu

Syene in Egypt, SyneliBal Axle. — wfien the strata dip in opposite direction;' 1

oommon central imaginary line, it is called a synclinal IJu

¥

Talus, — When fragmenU are broken off by the action of the weather from the face of a steep rock, as thej accumulate at its foot, they form a sloping heap, called a tains. The term is borrowed from the language of fortification, where talu$ means the out- side of a wall of which the thickDess is diminished by degrees, as it rises in height, to make it the firmer.

Tertiary Strata. — A series of sedimentary rocks, with characters which distinguish them from two other great series of strata, — tlie secondary and primary, which lie heMOih them.

Testacea, — Mollusoons animals, having a shelly covering.

Thin out, — When a stratum, in the course of its prolongation in any direction, becomes graduiUly less in thickness, the two surfaces approach nearer and nearer ; and when at last they meet, the stratum is said to thin out, or disappear.

Trap and Trappean Roehs, — Volcanic rocks, composed of Felspar, Augite, and Hornblende. — The various proportions and state of aggregation of these simple minerals, and differences in ex- ternal forms, give rise to varieties, which have received distinct appellations, such as Basalt, Amygdaloid, Dolorite, Greenstone, and others. The term is derived from trappOy a Swedish word for stair, because the rooks of this class often occur in large tabular masses, rising one above another, like the steps of a staircase.

Travertin, — A concretionary limestone, usually hard and semi- crystalline, deposited from the water of springs holding lime in solution.

TttffoT Tufa, — An Italian name for a variety of volcanic rock of an earthy texture, seldom very compact, and composed of an ag- glutination of fragments of scorieo, and loose matter ejected from a volcano.

Turbinated. — Shells which have a spiral or screw form structure.

Cnconformable, — See Conformable.

Veins, Mineral. — Cracks in rocks filled up by substances different from the rock, which may either be earthy or metallic. Veins are sometimes many yards wide ; and they ramify or branch off into innumerable smaller parts, often as slender as threads, like the veins in an animal, and hence their name.

Wache, — A rock nearly allied to Basalt, of which it may be re- garded as a soft and earthy variety.

Zeolite. — A family of simple minerals, including Stilbite, Mesotype, Analcinie, and some others, usually found in the Trap or vol- canic rocks. Some of the most common varieties swell or boll up when exposed to the blow-pipe.

Zoophytes. — Corals, sponges, and other aquatic animals allied to them, BO called because, while they are the habitation of animals, they are fixed to the ground, and have the forms of plants.

APPEIirDIX

;

Appendix.

A.

ft

History Of The Survey.

Thb foUowiDg letter and report, published in the Joomal of the House of Delegates of Virginia, Session of 1833-'4, relate to the history of the origin of the Geological Survey of the State of Virginia, the first report on which, that for 1835, was presented to the Legislature Jan. 11th, 1886.

#

Lbtteb fkom the Hon. Pbteb A. Bbowke, of Philadelphia,

GORRESPONDINO SbOBBTABT OF THB GeOLOGIOAL SoOIETT OP

Pennsylvania, to tub Govebnob of Vibqinla.

Philadelphia, Sept. 30th, 1833. To his Excellency John Floyd, Governor of Virginia :

Sib : Although I have not the honour of a personal acquaintance with you, I have no hesitation in making the present appeal to your patriotism and wisdom, not doubting but that I shall find in the great and growing interest of the subject to the country at large, and particularly to that portion of the Union over which you pre- side with so much dignity and discretion, a sufficient apology for occupying so much of your valuable time as will enable you to give the present commanication an attentive perusal.

I have recently returned from a geological excursion to Virginia. I entered the state near the head waters of the Potomac, passed thence to Winchester, followed the course of that fine valley to the Natural Bridge ; retracing my steps, I turned westwardly at Staun- ton, crossed the mountain at Jennings Gap, and visited the justly celebrated medicinal springs in that region ; returning, I went from Staunton through Charlottesville to Richmond, and down the James to its month. When this tour is taken in connection with a former visit to Wheeling, it will be conceded that I have seen enough of tlio state to enable me to form a rough estimate of its geological and mineralogical importance : and 1 do assure yon sir, that al-

thoagh mj anticipations were far from being meagre, I was aston- ished at the yastness and varietj of interesting objects in that department of natural history, that were constantly developing themselves, inviting the mind of man to reflection, and his hands to industry, and displaying at every step the wisdom and beneficence of the great Creator.

I determined npon respectfully suggesting to your excellency the expediency of a topographical, geological, niineralogical, and orgetological survey of Virginia. Should the enlightened represen- tatives of the freemen of voor state concur in this opinion, it will redound to the honor of all concerned, by the encouragement it will -give to the study of the natural sciences — by the enhancement in the value of lands in the interior, thereby euriching the state and its citizens, and giving a very proper check to unnatural migrations to the extreme west ; by bringing to light and usefulness innumerable valuable crude materials, thereby not only enlarging the field of manufactures and the useful arts, but furnishing carrying for the canals and roads already constructed, and assisting in new internal improvements in locations of equal importance. That I may not appear to be too enthusiastic, pardon me for pointing out some of the most obvious features in the geology of Virginia. Whether we consider the comfort and convenience of our species, or the indus- try and prosperity of a state, there is uo mineral prodn<;tion that can outvie in importance with that of eoal. In this country, where we have hitherto always had a superabundance of fuel, owing to the vast extent of our natural forests, the importance of a constant and abundant supply is not felt, and we are too apt to neglect properly to appreciate its value ; but it is not so elsewhere, and a moment's reflection will show that it ought not to be so here. Without fuel, of what use would be to us the metallic ores? for instance iron, which is now moulded, drawn, and worked into thousands and tens of thousands of useful instruments, from a knife to the complicated machinery of a steam engine, would forever remain an indissoluble and useless mass of matter without the aid of fuel. Even the steam engine itself, that colossus of modern machinery, without the assist- ance of fire, would be inactive and impotent.

The Rev. Mr. Conybeare, an eminent English geologist, speak- ing of the coal veins (or coal measures, as they are called) of his country, thus expresses himself:

"The manufacturing iodustry of this island, colossal as is the fabric which it has raised, rests principally on no other bape than our fortunate position with regard to the rocks of this series. Should our coal mines ever be exhausted it would melt away at once, and it need not be said that the effect produced upon private and domes- tic comfort would be equally fatal with the diminution of public wealth : we should lose many of the advantages of our high civil- ization, and much of our cultivated ground must be again shaded with forests to afford fuel to a remnant of our present population. That there is a progressive tendency to approach this limit is cer- tain, but ages may yet pass before it is felt very sensibly, and when

it does approach, the increasing difficulty and expense of working the mines of coal will operate hy successive and gradual checks against its consummation, through a long period, so that the tran- sition may not be very violent; our manufacturers would first feel the shock, the excess of populntion supported by them would cease to be called into existence as the demand for their labor ceased, the cultivation of poor lands would become less profitable, and their conversion into forests more so."

Where is the state in this Union — might perhaps safely ask, where is the country in the world — that can surpass Virginia in the variety of position and abundance of supply of tins valuable com- bustible? She possesses not only in common with her sister states, a liberal quantity of bituminous coal in her western and carbonace- ous regions, where, according to geological calculations, bituminous coal might be reasonably expected to be found ; but in the eastern di- vision of the state, within a few miles of the tide water of a majestic stream which empties its ample waters into the Atlantic Ocean, in a geological position where bituminous coal never would have been sought after, becan bituminous coal could not there have been ex- pected to have been found ; bituminous coal of a good quality, and apparently in great abundance, has been found ; nature seeming as it were, in this instance, to enable her to favor an otherwise highly favored land, to have defied all her own rules and baffled the skill of the gravest geologist, by depositing bituminous coal upon the naked and barren bosom of the uncarbonaceons granite! I have often wondered why this anomaly did not strike the capacious and highly gifted mind of Jefferson ; and why he or some other of the many reflecting men of Virginia, was not led by it to inquire what else there might be in store for the good people of that state ? By neglecting to seek for them, we ungratefully reject the proffered kindness of our Creator ; the laws of inanimate matter are, in this respect, in unison with those that govern animated nature. We are furnished with the material and means, but in order to stimulate us to useful and healthful industry, we must labor in their appropria- tion. God gives us the earth and the seed, but we must plough and sow, or we can never reap; so he has bountifully placed within our reach innumerable invaluable rocks, minerals and combustibles, but to eioy them, we must delve in the bowels of the earth, and having found them, we must by various laborious processes render them fit for our use.

To those who are accustomed to regard these things, it is difficult to determine which cause the most painful sensatims, to observe how few coal mines, in comparison to what might be, are opened in the neighborhood of Richmond, or the want of skill exhibited in the selection and working of those recently opened. Nor is the deposite of bituminous coal upon the granite, the only geological anomaly of this quarter. Proceeding from Charlottesville towards Richmond, almost immediately after you leave the talcose formation of the Bine Ridge, you are astonished at the fertility of the soil ; yon can scarcely persuade yourself that you are travelling over a

oonntry of primitive rocks. Soon, however, you discover that the fertility is not universal, bat confined to patches of a brick-red cover- ing that overlie the disintegrated materials of the primordial forma- tions, and upon seeking further into this carious matter, your sur* prise is not a tittle increased on discovering that this brick-red cover- ing owes its existence to the disintegration of a rock which, in most other places, is exceedingly slow to decompose, and which, when decomposed, forms a cold and inhospitable soil. It is the hornblende iienite. Here it is surcharged with iron, which oxidating by ex- posure to the atmosphere and moisture, the rock freely disinte- grates, and the oxide of iron being set at liberty, imparts its coloring to the ground and fertilizes the soil in an extraordinary degree.

Professor Hitchcock, in his report of a geological survey of Mas- sachusetts, makes the following remarks in relation to the effect of iron upon a soil :

No ore except iron occurs in sufficient quantity in the state to deserve notice in an agricultural point of view. In the west part of Worcester county, the soil for a width of several miles across the whole state, is so highly impregnated with the oxide of iron, as to receive from it a very deep tinge of what is called iron rust. This is particularly the case in the low grounds, where are frequently found beds of bog ore. I do not know very definitely the effect of this iron upon vegetation, but judging from the general excellence of the farms in the Brookfields, Sturbridge, Hard wick, New Brain- tree, Barre, Hubbardston, dc, I should presume it to be good. Certainly, it cannot be injurious ; for no part of the county exceeds the towns just named in the appearance of its farming interests, and nearly all the county, as may be seen by the map, is of one formation. It would be an interesting problem, which in that county can be solved, to determine the precise influence of a soil highly ferruginous upon vegetation.'

Next in geological and statistical importance, I would place the mineral springs of Virginia; und these would form a legitimate subject of investigation to those who should be appointed to con- duct a geological survey.

I am not aware of any portion of the country of the same ex- tent, possessing an equal number and variety of mineral springs as the counties of Bath, Greenbrier and Monroe. This is a subject upon which one might easily compose a book, but I must confine myself to a few lines. The waters are thermal and cold ; the for- mer of various degrees of intensity. They hold in solution a variety of metals, earths, acids and alkalies, combined in various proportions, and suited to relieve the sufferings of invalids from a number of dis- eases. Mineral springs of less interest than these have excited the attention of the learned in almost every age and country, and Vir- ginia owes it to her high mental standing, independently of every other consideration, to assist the cause of science by investigating the causes of the high temperature, and making accurate analyses of these valuable waters. It is the duty of states, as it is of indi- viduals, to furnish their quota to the general stock of information ;

and this is pecnliarlj the duty of a republioan state, whose happi- ness, nay, whose very political existence depends upon an improved state of the minds of its citizens. Mr. John Mason Good, in his *'Book of Nature," after describing the state of society in the middle ages, says : We have thns travelled over a wide and dreary desert, that like the sandy wastes of Africa, has seldom been found re- freshed by spots of verdure, and what is the moral? That igno- rance is ever associated with wretchedness and vice, and knowledge, with happiness and virtue. These connections are indissoluble ; they are woven in the very texture of things, and constitute the only substantial difference between man and man," and I would add, between state and state.

Has the heat of these waters any connection with volcanic phe- nomena? Or is the temperature entirely chemical, originating in the decomposition of sulpharet of iron, as I suggested some years ago in a paper published upop the subject? At the Hot Springs, the hot sulphur water and the cold pure water, issue out of the calca- reous rock at the base of the Warm Spring mountain, within a few feet of each other. One of these Virginia springs makes a copious deposit of oalcareons tufa, and at another, you perceive newly formed chrystals of sulphate of iron. The White Sulphur spring takes its name from a rich white deposite, and the Bed Sulphur from one of that color. If tliis is not an uncommon and a highly interesting section of the country, calling aloud for investigation and meriting legislative interference, then have I taken an entirely erroneous view of the subject.

The Warm Spring mountain is white sandstone. The rocks of the Valley of the Hot Springs are calcareous argillaceous and sili- ceous. They are all nearly vertical. At first the two former and afterwards the two latter, alternate. They have all been deposited in a horizontal position, and between their narrow strata are thin layers of clay covering organic remains. Those of the lime and slate are principally zoophytes. That of the siliceous is the fossil described by Dr. R. Harlan, from a ecimen obtained by me in the western part of the state of New York. He supposed it to be a now extinct fossil of the family Fnooids ; and he has called it Fueoide BrongnidotiCy in honor of M. Brongniart. Bnt I suppose it to be animalj and to belong to the family of the encrinites.

The mountain ranges of Virginia are more numerous, and the valleys consequently narrower than in Pennsylvania, bnt some of them are very interesting. The great valley, as it is sometimes called, or par excellence, the valley situate between the Blue Ridge and the North and Alleghany mountain, is by far the most ex- tensive. The rocks often obtrnde, rendering the soil rather scanty, but nevertheless this is a fine district of country.

I could find no fossils in this rock. In regard to the metallic ores I would observe, that I discovered sufficient indications of their ex- isting in Virginia in quantity sufficient to justify a more accurate examination. Iron abounds in almost every part of the western section of the state ; traces of copper, lead, manganese and chrome,

have also been disooyered near the Blue Ridge ; and the gold found in Orange ooanty is eqaal to any found ia the Carolinaa or Greorgia.

I have never seen anj thing that exceeds the richness and van- etj of coloring of the serpentine of the Bine Ridge. This mineral is easilj cut, and the finenera and closeness of the grain renders it snsceptible of a high polish ; at Zoblitz, in Saxony, several hundred persons are employed in its manufacture. Besides the minerals be- longing to the talcose formation, and generally accompanying ser- pentine, are many of them valuable in the arts, for instance stea- tite, (soapstone,) tfdo, chromate of iron, chlorite slate, and native magnesia. A geological survey would, most probably, lead to the discovery of most of these minerals.

I could make large additions to this communication, but for the fear of trespassing upon your patience. I will, therefore, close my observations with noticing two instances of want of confidence in the mineral productions of your own state, which I am persuaded that a geological survey would tend to correct. I met many wag- ons lojed with sulphate of lime, (gypsum), from Nova Scotia, being taken to the interior to be used as a manure ; but I did not see one wagon employed to bring carbonate of lime (common limestone), from the inexhaustible quarries of the great valley to any other dis- trict to be used for the same purpose. In the beautiful and flour- ishing city of Richmond, I observed the fronts of two stores fitted in the new and fashionable style with granite (so called), (sienite), from Massachusetts, while there exists in the James river and on its banks, in the immediate vicinity of the town, rocks of a superior quality, in quantities amply sufficient to build a dozen cities.

I have the honor to be, sir,

Your obedient servant,

Pbteb a. Bbowitb.

RspOBT from the Selbot CoifMrrm of the Gbnkbal Assembly

of ViBOlNIA, TO WHOM WAS BEFEBBED CEBTAIN MsMOBIALS FBOM

Morgan, Fbedebiok and Shenandoah Oountieb, Pbatino fob A Geolooioal SasvET of the State, with a view to the

Disoovebt And Development Of Fts Geological And Minebal Bbsoubces.*

The select committee to whom was referred sundry petitions from the counties of Morgan, Frederick and Shenandoah, on the subject of a geological and chemical survey of the state, have had that subject under consideration, and respectfully Report :

1. In looking to the example of other countries, as well as of several of our sister states, it would appear that great practical im- portance is attached to the geological and chemical inquiries which

♦ Tbc lanTuace and Bubatancc of this report bear clear evidence of havine been preparryl for the committee by WilHani B. Roirers. at that time Professor of Natural PhiloAophy and Chemistry in William nnd Mary Collcsc, and who was subsequently appointed director of the Qeologioal Survey of the state.

they have respectively iostitnted. In ooDJunction with extensive and minute topographical surveys, many of the govern men tu of Eu- rope have set on foot systematic jsnd detailed inquiries into tlie geological features and mineral resources of their respective do- mains. France, Sweden, Russia, several of the German and Ital- ian states, and Great Britain, have shown great activity in push- ing forward these investigations. The latter government espe- cially, has distinguished herself hy liberal and steady zeal in de- veloping those natural resources of the land, which form the basis of her wealth and power. The ordinance map of Great Britain, which is yet only in part published, and which, besides topo- graphical, contains also geological details, is looked upon as a signal proof of the liberal spirit and practical wisdom of the gov- ernment of tiiat country. In this country, likewise, a growing couTiction of the great importance of such inquiries has led several of the states to make provision for extensive practical surveys, on a plan somewhat analogous to those conducted in Europe. The sur- vey of Massachusetts, under the soperintendence of Profes.'K>r Hitchcock, of Amherst College, has already been completed, and judging from the immense mass of details, under the head of eco- nomical geology, embodied in his comprehensive report recently published in a large octavo volume, there can be no doubt that the community for whose benefit the survey was undertaken has been amply gratified by the important discoveries it has brought to light, and the valuable practical bearinpfs of most of its details. In this report, we behold a fitate possessing but little variety of geo- logical features, displaying an amount and diversity of resources, (in part until now undiscovered, and never before arranged so as to be understood,) which cannot be contemplated without pride and satisfaction. Maryland and Tennessee are following the wise ex- ample of Massachusetts, and there is reason to believe that "New Jersey, Pennsylvania, and New York will, either during the present or the next year, authorize similar undertakings. In the prelimi- nary report of Prof. Ducatel, of Maryland, will be found the most abundant evidence of the practical benefits which are to be an- ticipated from such researches. Though based upon a merely super- ficial reconnoissance of the state, this vsluable docnment develops a number of interesting facts in its geology, of which little or noth- ing has been previously known, and from which new impulses to the enterprise of extensive districts of the state may be confidently expected to proceed. The subsequent report recently presented to the legislature of Maryland, embodying all the details of the first yearns operations in regular survey, has not yet reached us, but from what we learn, the developments which it contains are of a character to enlist the wisdom and patriotism of the state very warmly in the prosecution of the survey. Of the practical utility of the researches now in progress in Tennessee, the published re ports and other documents relating to the subject, speak in the most unqualified and encouraging language. The labors of Professor Troost, to whom this survey has been committed, have already

contribated a large amonot of usefal informatJon relative to the mineral and agricnltural resources of the soil of Tennessee. In the other states above alluded to, adoption of similar measures for the investigation of their natural territorial resources, has been de- layed from year to year by considerations of economy, to which the heavy debts accumulating in the prosecution of public improve- ments, have constrained them to defer. But no doubt appears to have existed of the real utility and highly important practical bear- ings of judiciously conducted geological and chemical surveys. Indeed, notwithstanding the heavy incumbranoes under which some of those states are now laboring, projects of such surveys are at this time under discus!$ion in their legislatures ; and there seems to be no doubt, that either now or at some early day, the necessary provisions will be made for commencing the investigations desired. 2. Witnessing the valuable results of these researches in Europe, and in some parts of the United States, we should of course antici- pate similar benefits from enquiries of this nature conducted within our own territory. Nor would it be necessary, in order to feel con- vinced of the utility of such a survey as applied to Virginia, to refer in detail to those particulars in the physical character of the state, upon which it would bear with the most direct and prominent ad- vantage. All are willing to admit the great extent and value and diversity of our mineral wealth, and at the same time to confess that its distribution through our territory, its precise boundaries in any one locality, its exact nature as ascertained by science, and its susceptibility of economical and proBtabie application to the pur- poses of commerce, manufactures, and the arts of life, are matters of which scarcely anything as yet has been accurately determined. The mere surmises of iguorance or the imperfect observations of the inexperienced explorers who have examined without any ade- quate lignts to direct their investigations, appear to have furnished nearly all the knowledge on these points, of which we have as yet become possessed. To feel thus assured of the existence of a great variety of mineral riches within our territory, and at the same time, except in a few instances, to have availed ourselves of but little of the benefits it proffers, and to know but little of its position, nature or extent, are certainly in tliemselves powerful reasons for the adoption of some scheme of systematic, minute and extensive re- search. But, however obviously the advantages of such surveys might be inferred from these considerations in connection with the acknowledged benefits which other states have derived and are de- riving from them, your committee have felt it incumbent to enquire more particularly into the specific bearing which enquiries uf this nature would have upon all the great divisions of our territory. In attending to this point, a number of interesting particulars have come to their knowledge, some of which are perhaps not generally known, and all of which confirm them in the belief that such a sur- vey as the one in question, cannot fail to prove eminently advan- tiiieous to our state. Most of the facts here referred to have been discovered by mere accident, and by persons seemingly unconscious

of their importance; oonseqnently, little or no improvement of them has heen made, and no researches undertaken to ascertain their real extent or valae. In adverting to the beneficial applica- tion of SQch a survey to the several great divisions of our territory, your committee feel at liberty to touch only on some of the more prominent particulars in which its utility would be felt; and in- deed, it is only in the actual progress, or at the completion of the investigation, that the most important of its practical bearings can be appreciated and understood. Discoveries of great general in- terest and of invaluable local importance, would, there is reason to believe, reward even the earlier efforts of those connected with the enterprise ; and the districts of the state, at present almost deserted from supposed meagreness of resources, would behold, spread out beneath their soil, the rich earths, which were soon to diffuse fer- tility over their hills and plains, or the valuable rocks and ores from which enterprise was to derive new incentives to exertion.

8. Commencing witli the tidewater part of the state, your com- mittee would remark that the vast marine deposits of shells and other calcareous matter which underlie a great part of this region, may be considered practically, as well as in a scientific aspect, as one of the most important features in the geology of the state. The exhausted soils of many of the eastern counties are already exhibit- ing the most astonishing proofs of the fertility which this calcareous matter is capable of bestowing, and it may be confidently expected that when a more extensive and systematic attention to the employ- ment of this manure shall have been adopted throughout eastern Virginia, a degree of agricultural wealth ana prosperity will be real- ized, of which a few years since, or even at this time, it would be difficult to conceive. To the rapid, general and successful extension of this ameliorating system, there can be no doubt that a geological and chemical examination, extended to all the eastern counties, would be in a high degree conducive ; in most of them marl has already been discovered, cliffs of it appear qn all our rivers, and sometimes for miles an uninterrupted bed of this precious manure forms one or both of the confines of the stream. But of the com- position of its numerous varieties, of the districts which they sev- erally occupy, and of the value of ttie various earths with which they are associated, but little general or systematic knowledge has been acquired. To one individual, the able editor of the Farmers' Register, the state is indebted for nearly all that has been done on the subject. But how important would it be to investigate the ex- tent and character of this deposit more minutely ; to trace it up- wards from its first appearance near the mouths of our rivers ; then, by transver:>e lines, to explore all the counties in its range, and at each step of the investigation to ascertain its agricultural value by chemical analyses I

Within the tidewater district also, but in a region to which the common marl does not generally extend, another deposit of even higher fertilizing properties than the former has recently been dis- covered. This substance, called green sand, from its consisting of

granular particles of a green aspect when dry, ia geologically an older depo%ite than that which embodies the ordinary shell marL In the beds of the latter, however, in many sitnatioDs, a very large percentage of the green sand has been discovered, and the value of the marl is believed to be much increased by the presence of this ingredient. The extent of this immense green sand deposit is yet conjectural, but that it reaches, with perhaps no interruption, from the Potomac to the Roanoke, may be confidently a.sertea. It shows itself on our rivers at a distance varying from a few miles to 20 or 30 from the head of tide, and it may be interesting to remark that the geologist of Maryland, guided by the experience of those who ascertained its existence in Virginia, has recently discovered a con- tinuation of the deposit throughout the neighboring state. Of its relative value in the different localities, nothing is yet known ; re- specting the deptli and breadth of the deposit, scarcely anything has been ascertained. Here then would be an important field of geo- logical and chemical enquiry, and one in which the agriculture of lower Virginia could not fail to be deeply interested.

Associated with this deposit, and generally forming the superior stratum, is an extensive formation of selenite or gypsum. Whether this be an invariable attendant of the green sand, is of course unde- termined, since of tliat deposit so little is yet known ; but so far as observation has yet extended, it would seem to be a gen- eral associate of the freen sand, specimens from the Potomac, Rap- pahannock, Panmnkey, and James rivers agreeing in containing some portions of gypsum.

In this region, too, a variety of clays suitable to different species of pottery are known to exist, an examination of which would doubtless lead to the introduction or extension of an important branch of industry. Alvm earth and copperas earthy of which im- mense quantities are found in Maryland, and applied to the manu- facture of alum and green vitriol, exist also in this part of our state, and probably in greats abundance. Bog iron ore, one of the most valuable of all the ores of that metal, would also be met with exten- sively. Bordering on this region, at its upper limit, a variety of valuable products might be expected. In the south, especially, the secondary rocks immediately adjacent to the granite ledge would be deserving of particular attention. In this vicinity might be antici- pated a third deposit of fertilizing marl, identical in position with the gimpowder marl of New Jersey. A stratum of magnesia earth has, within a few years, been discovered at one point along this line, and it is not improbable that its value, cither in agriculture or in the manufacture of epsom salts, may lead hereafter to its profitable employment. Chemical examination would determine the valne of these various matters, and new incentives might thus be given to the manufiicturing enterprise of this portion of the state. The sev- eral varieties of water furnished by springs and wells would also form a subject interesting to health, and in other respects practically useful.

4. The space extending from the granite ledge to the Blue Ridge,

embracing all the yarieties of primary rock, containing the yet imperfectJy traced gold region, the bitaminous coal fields, and a vast variety uf other mineral wealth, is next to be considered. Here, to trace out the gold region entirely through the state, would be an important and useful work. From what is already known of this deposit, there is every reason to augur its great extent and value. Indications of this metal have been found even in Goochland and at other points far removed from the supposed line of the formation. A systematic enquiry on the subject would evidently result in much practical advantage, not only by opening up new discoveries, but by preventing those ruinous expenditures which are occasionally in- curred for want of the proper guides to enquiry and research. The coal field of Goochlana, Chesterfield, and Powhatan, from which eastern Virginia has already reaped so many benefits, would present a most interesting subject of geological examination. To ascertain the dips and convolutions of the various strata overlying and sub- jacent to the coal, ond to investigate more attentively than hos yet been done the line of outcrop connected with the coal, might lead to discoveries of no small importance to the prosperity of the state. That the real extent of those coal beds is not yet accurately known, is evident from the discovery of indications of this mineral in situa- tions at some distance from any of the workings; for instance, on the line of the contemplated Richmond and Fredericksburg rail- road.

In Prince Edward too, bituminous coal is found, and there is reason to believe that the seam from which the specimens have been derived forms part of a very extensive bosin of this mineral. Nor is it improbable that between tlie Richmond and Prince Edward deposits and in the same geological range towards the north, this valuable mineral might be brought to light. Among the granite and feldspar of the region we are now considering, valuable deposits of porcelain clay are already indicated. A stratum of this sul)stanco is known to exist in the vicinity of Charlottesville, and specimens have recently been obtained from a bed in Goochland, which in ap- pearance, give promise of considerable value. That this earth will be found in many places throughout the region referred to, there can be no doubt. The rock feldspar, from which it is produced by the slow action of the elements, is an important constituent of our granite, and exists in some places in a separate mass. It is with this rock that the earth is mingled in certain proportions in the fabrication of porcelain; and tlie very beautiful material of this nature, now so successfully manufactured in Philadelphia, is formed of the clay and feldspar procured in the vicinity of that city and Wilmington, localities in the same geological range with the region in onr state to which we now refer.

In this region too, will be found valuable beds of iron ore of various kinds, some of which are already known and wrought. Serpentine and magnesian rocks also oc-ur, in connection with which the valuable ore from which chrome yellow is manufacture*!, may be expected to exist. In the vicinity of the Southwest and

Baffalo motmtainSf on both sides, a variety of important minerals are embedded. The shale of this ridge iu Amherst and other places yields, by the action of the atmosphere, great quantities of green vitriol, which impregnating the watr as it filters through the rock, gives rise to some of the most powerful chalybeate springs in the United States. To the east of this ridge a belt of blue limestone appears, which would seem to be a continuation of the Potomac marble. From the continuity of this narrow vein through Maryland, high up into Pennsylvania, it would appear to constitute a very im- portant feature of the geology of this district. It crosses the Po- tomac, and rises in one or two places before it appears very dis- tinctly at EverettsviUe, and then shows itself very abundanUy in Amherst, where it is associated with marble of a superior quality. On the eastern side of this belt, is a large vein of flint, which ex- perience shows to be equal to the common gun flint. Copper occurs very abundantly on the west side of the Bufifalo ridge, and would probably be found interruptedly in the same range throughout the state. In the continuation of this line, it is found abundantly in Maryland, associated with iron and manganese. These metals would appear to be associated with it in Amherst. The vein of copper in this county was largely worked prior to the revolution, and the im- pression prevails that a valuable percentage of gold is contained in the ore. Such is the fact in regard to a copper ore which is now wrought in Now Jersey, and analysis might be usefully directed to this point with reference to the Virginia ore. The particulars here stated are only a few of what might be gleaned from the personal observations of intelligent farmers or scientific tourists, wno have paid attention to the geology of this region, but they are abundantly sufficient, in the mind of your committee, to evince the advantages which this section of the state would derive from systematic geologi- cal and chemical enquiry.

5. The valley of Virginia would offer a multitude of valuable discoveries, and among them extensive beds of coal would certainly be numbered. The anthracite recently discovered in the counties of Berkeley, Augusta, and Morgan, and the extensive mines of bitumi- nous coal of Hampshire, indicate what may be anticipated from mi- nute and jjudioious research. If we look to the inexhaustible depos- ites of this precious mineral which the enterprise of Pennsylvania has brought to light, and with which, perhaps, more than any other of her vast mineral resources, she is now building up the permanent fabric of her wealth and power, with what satisfaction should we welcome a discovery which, properly itnproved, may lead to an equally enviable c<mdition of prosperity in one of the loveliest and richest sections of our state. In this region, the noble ranges of the North and Warm Spring mountains, with their numerous subsidiaries, would furnish an almost unexplored field to the geologist. Valuable metallic ores, in addition to those already discovered, and new medicinal springs would here reward his labors. The sandstones, limestones, slates, and nrjarbles, yet reposing unbroken in the hills, would all be subjects of interesting observation. He would also ex-

amine the rich saline deposites of the oaves, and gjpsam with which it is sometimes abundantly associated. The beautifol and copions fountains in the Warm Spring valley, including the Warm, Hot, Sweet, Alum, and other springs, would claim his scientific scrutiny. The other waters, such as those of Bath in Morgan county, and Au- gusta, would also bo examined. These and a variety of other objects to which geological and chemical enquiry might be profitably directed in this region, have an importance which must give peculiar interest to the prosecution of such researches in the great valley of Virginia.

6. beyond the Alleghany we behold a region of almost unparal- leled natural riches, llere we have the vast bituminous coal forma- tion of the went, as extensively displayed as in Pennsylvania; and in addition, salines and a gypseous formation with which even New York cannot compete. The immense strata of this region, sweeping with a gentle inclination from the mountains, extend far west, until they reach the Mississippi in nearly horizontal planes. The ocean that once rested on this vast tract, besides the legible impressions of his former sway, visible in almost every rock, has left deep in tlie earth, and in some places extending to its surface, the rich treasures of salt with which its waves were once freighted. In some places as near Abingdon, this saline matter would appear to exist beneath in massive form. Amid the spurs of the Alleghanies are abundant evidences of coal ; metallic ores, among which may be enumerated lead and iron, are also found in this western region. Here too, are poured out many of those healing waters to which crowds of inva- lids now annually resort. In a word, this portion of the state teems with matter of interesting enquiry. If et it is only at a few points that its treasures have been opened up, and but little certain is yet known of their relative arrangement, of their extent, or their comparative value. This vast territory is destined by its mineral riches alone to become at some future day one of the most prosperous and wealthy districts of the state, and no part of Virginia is more deeply inter- ested in procuring a geological survey.

7. Besides the numerous points of enquiry alluded to in the above brief review of our territory, there is one investigation which would be applicable to all sections of the state, and which would undoubtedly contribute to the general benefit of our agriculture. We refer to a systematic analysis of all the important varieties of soil within the state. This would be a work of great labor, but would unquestionably repay the state one thousand fold.

8. Keeping permanently in view the peculiar practical bearings by which such a survey should be directed, a proper attention should also be paid to those general and scientific relations which the progress of the investigation would disclose. In many instances, the generalizations of science would be found of great utility in guiding observation ; and the determination of many interesting questions of a purely scientific nature, would be incidental to the practical researches of the geological and chemical enquirer. The relative ages of all the great formations of the state, might event- ually be made out; the periods at which disturbing causes, at many

points, broke up and contorted the Btratification, and the relations ' of the varioQs agencies which have formerly been in operation in oar territory to those now in action, both as to quantity and kind, wodld all be elucidated in the progress of the survey. The geolo- gists of Europe are so well aware of the interest that attaches to tins portion of the United States, on account of the diversity and extent of its formations, that they are at this moment looking with impatient anxiety tor some systematic effort to unfold its true phys- ical character, and to bring fully to light treasures that lie hidden beneath its sur&ce.

In the execution of the proposed geological and chemical survey, your committee woold observe, in conclusion, that the mcst advisa- ble plan would seem to be, to divide it into two parts : namely, 1st. A geological reconnoissance of the state, with a view to the general geological features of our territory, and to the chemical composi- tion of its soils, minerals and mineral waters : and, 2d. A detailed geological survey of the various sections of the state. The first part of the plan would possess of itself a separate and independent value, would be attended with but little expense, and would furnish to a succeeding legislature the most satisfactory means of estimating the value of a detailed survey, and of deciding or pausing at the point to which we should then have attained, or of proceeding directly to the execution of the entire scheme.

In conformity to these views, and with the object of advancing directly to the accomplishment of the first part of the plan, your committee beg leave respectfully to report the accompanying bill.

An Act to authorize a. Geological Reconnoissance of the State, with a View to the Chsmioal Composition of itb Soils, Minerals, and Mineral Waters.

(Ab unonded ftom the Mil reported by the committee, and passed hj the OcneFa] As- sembly of VlrcrialA.)

1, Be it enacted by the general anembly That as soon after the passage of this act as it may be convenient, it shall be the duty of the lK>ard of public works to appoint a suitable person to make a geological reconnoissance of the state, with a view to the general geological features of our territory, and to the chemical composition of its soils, minerals, and mineral waters, and to report to tne next general assembly a plan for the prosecution of a geological survey of the stnte, together with such facts as may have come to his knowledge during the progress of said reconnoissance, illustrative of any advantages likely to accrue from a more complete examination.

2. Be it further enaeted That the said board of public works shall have authority to allow to the geologist who may be employed under the provisions of this act such compensation as they may deem reasonable to be paid out of any unexpended moneys in the treasury : Provided That such compensation shall not exceed the sum of fifteen hundred dollars.

8. This act shall commence and be in force from the passing thereof.*

This act was passed March 6, 1636.

B. Assistants Employed On The Survey.

The assistants employed on the survey, some for a single year and others for a longer time, were, 0. B. Ilayden, Geo. W. Boyd, J. B. Rogers, Israel Slade, Caleb Briggs, II. D. Rogers, Dr. W. E. A. Aiken, Samael Lewis, Thomas S. Ridgeway, R. E. Rogers, and for a part of one season Mr. M. Wells.

The following paragraph is found in the author's copy of the Report for 1836, following the fourth paragraph on page 113:

" The composition of this ore, (Iron ore) now not known, would throw great light on this interesting result, and might enable those engaged in the Iron works of the country, to secure a uniform pro- duction of this more valuable form of metal, instead of being sub- ject to the capricious results of having cast iron at one time, and at another, without any apparent reason, a superior quality of steel."

D.

In the original work the paragraphs inclnded in pages 366, 867, and a part of 368 are in a different order from that here given. The present arrangement is adopted in conformity with a correc- tion made by the author in his own private copy.

E.

NITRATES m CAVE EARTHS.

FcoM PftOOKBOiTias or Bostoti Sooibty or Natukal Histobt, Vol. 5, p. 88i, 1S50.

Professor William B. Rogers remarked that from his observa- tions in the Caves of the Middle and Southern States, he was satis- fied that the earthy deposit containing the nitrates, known in some places as Petre dirt, was chiefiy derived from the overhanging and adjacent rocks, and not from sediment brought into the Cave by ex- isting or former streams. The limestone, in which tlie nitriferous caverns are found, often contains a large amount of siliceous and ar- gillaceons matter, and in some instances, a marked proportion of or- ganic substances. The more pervious layers, gradually deprived of their carbonate of lime by the leaching action of the water in filter- ing from above, are reduced to an earthy mass, the mere caput

mortuum, as it were, of the original rock. In some cases this de- composition pervades the stratum for a great distance ; the residu- ary, fine-grained, ashy clay retaining the lamination and bedding which it had before the change. In course of time, the earthy mass falls to the floor by its own weight, aided, perhaps, by occasional tremors of the ground, or it is detached by the load of stalactites suspended from it below, and thus comes within the levelling and transporting action of the streams flowing tlirough the £ave.

As to the proilnotion of the nitrates with which the Petre dirt is more or less imnregnated, Professor Rogers thought that it could not, in any large aegree, be referred to the excretions and other re- mains of animals occasionally found in these caves ; since the quan- tity of nitrogen reauired fur this purpose would far exceed such a means of supply. Besides this, the nitrates are found in the earthy mass while it is still adhering to the roof or walls and far removed from the organic matter supposed to be buried in the floor. Nor can we regard the nitrogen as chiefly derived from organic sub- stances in the decomposing rocks. For, in the case of some caves producing Petre dirt, the surrounding limestone contains only a trace of such ingredients. We must, therefore, refer the formation of the nitric acid, and ultimately the nitrates, to mutual chemical reactions between the porous calcareons earth and the contiguous atmosphere.

F. The Growth Of Stalactites In Caves.

Fbox PBOOBZDXNoa or THB Boston Societt or Natubal Hibtobt, Vol 6, uro 88<L

185S.

A drop of water charged with Carbonate of Lime is seen to form at a ])articular point of the roof and after its descent, another drop, by the same mechanical causes, takes its place. It is not necessary to suppose a hole around which the concretion may col- lect. Usually there is none. At the margin of the drop where it thins away to a film, evaporation and the loss of carbonic acid com- bine to canse a precipitation of part of the dissolved carbonate, which on separating, attaches itself to the rock in the form of a very delicate white ring corresponding to the margin of the liquid. Each succeeding drop deposits a similar ring in contact with and beneath that already formed, until the whole is prolonged down- wards in the shape of a quill-like tube. This, from its. vertical posi- tion, invites the water of the adjoining part of the roof to descend along its outer surface, and now an exterior and more rapid growth begins. Usually the former process continues to operate for a long time after tlie external growth has commenced ; so that the stalac- tite, in some cases, retains its open central canal until it has reached a length of a foot or more, and a diameter at its base of two or three

inches. As the water which flows along the ontside of the tuhe, parts at each step with a portion of its calcareous charge, and thns

Srows oontinnally less capahle of forming the deposit, the rate of epojition must diminish somewhat regularly from the upper to the lower end of the mass. Hence it is that stalactites, formed in posi- tions where their growth on all sides is freely permitted, have always a iharply eonieal or tapering farm.

The drops which fall from these pendants to the floor, still retain a portion of carhonate of lime in solution ; hut as the shocks of the impact and the spreading of the liquid greatly favor the escape of its carhonio acid, a further deposit must he formed in this position, and thns the stalagmite grows upwards to meet the stalactite grow- ing downwards, until, in many cases they unite to form a column reaching from the floor to the ceiling of the cave.

As in general the infiltering water follows the joints and planes of stratification of the limestone rock, the fashion or pattern of the stalactite drapery will he more or less determined hy the position and arrangement of these divisional surfaces. Where, as in parts of Weyer's dive, in Virginia, these planes of hedding are steeply in- clined, and meet the roof in a series of parallel line, the concre- tionary action seems to have commenced hy forming parallel rows of stalactites along these lines. This process, in certain places, has gone on until hy lateral union of the adjoining pendants of each row, they have heen transformed into parallel sheets ofstone which, in some instances, extend from the roof to the floor. From their great extent, and a degree of thinness which in part renders them translucent, these sheets are capahle of being thrown into sono- rous vibration by a blow from the heel near the ground, and under these circumstances they emit a musical sound of great depth and force.

G:

Secondary Formations In Virginia And North

Carolina.

Fboh Peockkdings op THI BO6TOK 60OIETT OP Natvsvl niSTOBT, Vol fi, p. 14, 1854.

Prof. W. B. Rogers exhibited a series of fossils from the middle secondary belts of North Carolina, Virginia, Pennsylvania, and Mas- sachusetts, chiefly, he said, with a view of calling attention to the evidence afforded by some of them, of the close relation in geologi- cal age between what has been called the New Red Sandstone of the Middle States and the Connecticut Valley, first designated by Prof. H. D. Rogers as the Middle Secondary Group, and the coal bearing rocks of Eastern Virginia and North Carolina.

Prof. R. referred to the existence in Virginia of three distinct belts of these rocks. The most eastern of these, extending almost continuously from the Appomattox river to the Potomac, includes

the coal-fields of Chesterfield and Henrico Counties. The middle tract, about tnrenty-five miles vest by south of the preceding, is of much less extent, and has not jet furnished any workable coal seam. Somewhat intermediate in trend to these is a belt of analogous rocks in North Carolina, commencing some distance south of the Virginia line and stretching southwestwardly across the state, and for a few miles beyond its limits, into South Carohna. This area, first mapped by Prof. Mitchell, includes the coal bearing rocks of Deep river. The western belt extends, with two considerable interruptions, en- tirely across Virginia, being prolonged towards the southwest in the course of the Dan river in North Carolina, and towards the north- west through Maryland, Pennsylvania, and New Jersey, forming what is usually called tlio New lied Sandstone Belt.

EisTEnx AND Middle Belt of ViitonfiA and Eastern Belt of

NoBTU Carolina.

From an examination some twelve years ago of the fossil plants of the most eastern of the Virginia belts here designated, Profl Rogers had been led to refer tliis group of rocks to the Oolite series on or near tl>e horizon of the carbonaceous deposits of Whit- by and Scarborough in Yorksliire. Some years later he discovered many of the same plants in the middle belt of Virginia, and in the summer of 1850, he found several of these plants in the coal rocks of Deep river, in North Carolina. In each of the latter districts we meet with Equisetum columnare, Zamites, and a plumose pl.tnt referred to Lycopodites, and strongly resembling L. WUliamtonU of the Yorkshire rocks. These are among the usual forms occur- ring in the easternmost of the Virginia belts.

Besides the fossil f)lants common to these three areas, the.v con- tain two species of Posidonomya and two of Cypris. Of the Cypri- diB, one species has a smooth, the other a beautifully granulated carapace. They are both very small, seldom exceeding an inch in length and in width. Both species of Posidonomya difier in proportion from the P. minuta of the European Trias, but one of them strongly resembles the P. Bronnii of the Lias, although of larger dimensions.

Prof. Rogers remarked upon the uncertainty which exists as to the true nature of the sinall shell-like fossils, which being assumed as molluscs, have been referred to Bronns genus Posidonomya. But, whatever may be their zoological nfiinities, the fossils now under consideration have great interest, as affording further means not only of comparing together the mesozoic belts of North Caro- lina and Virginia, above referred to, but of approximating more justly than heretofore to the age of the so-called New Red Sand- stone, or Triassic rocks which form the prolonged belt lying farther towards the west.

In the report of Prof. Emmons, published in the autumn of 1852, mention is made of the remains of Saurians in the Deep river de- posits, as well as of the Posidonia and Cypris, and of an Equiso-

tjtea, a Lyoopodites and other allied forms, together witii a naked, rather ftpinous vegetable, regarded by him as a cellalar cryptoga- mous plant.

In view of the general identity of the fossils thns far found in the Deep river and the Middle Virginia belts, with those of the most eastern deposit in Virginia, viz.. that including the coal of Chester- field, Prof. Rogers maintained that the general equivalency of these three areas may be regarded as established, and therefore the Deep river belt of North Carolina as well as the Middle Virginia belt ought to be placed in the Jurassic series, not far probably above its base.

"Westehn Belt of Nobth Cabouxa. akd Viroikia and its ex- tension TOWABDS THE NoBTHEAST FOBMINO TUE 60-CAfJ.ED NeW Ked SANDSTONE OF ViBOINIA, PENNSYLVANIA, AND NeW JeRSET, AND FBOBABLT OF THE V ALLEY OF THE CONNECTICCT.

In North Carolina, on the Dan River, where the rocks include one or more thin seams of coal, the same Cypridse or Posidoniie are found in great numbers in some of the fine-grained shales and black fossil slates. The latter were noticed as early as 1839, by Dr. G. W. Boyd, while on the Virginia Geological Survey. Re- garding this fossil, of which specimens were also obtained about the same time from the middle belt in Virginia, as identical with the Posidonia of the Keuper, Prof. Rogers had, many years ago, announced the probability that a part or all of the great western belt was of the ago of the Trias, instead of being lower in the Me- Bozoic series.

Specimens of the Posidoniie and Cypridre, from both belts in North Carolina, and from the eastern and middle belts in Virginia, were exhibited by Prof. Rogers at the Albany meeting of the Ameri- can Association of Science in 1851, for the purpose of showing the close relationship between these deposits in geological time. Among the specimens from the Dan river. Prof. Rogers on the present oc- casion referred to the impression of a Zamite leaf and a joint of Eqnisetum colnmnare. Prof. Emmons, in the report above re- ferred to, speaking of the marly slate of this system, says it dif- fers in no respect from that of Deep river, bearmg the same fossils, Posidonia ana Cypris, in great abundance.*'

In the belt in Virginia, towards the Potomac river, Prof. Rog- ers had lately found immense numbers of the same Posidoniss and Cypridfe, crowded together in fine argillaceous shales, and at sev- eral points he had met, in the more sandy rocks, vegetable impres- sions, which, although obscure, are strongly suggestive of the leaves of Zamites.

In the same belt in Pennsylvania, in the vicinity of Phenixville, early last spring, Prof. H. D. Rogers discovered Posidoniae in great numbers in a fissile black slate, and on subsequent examination, the same beds were found to contain layers crowded with the casts of Cypridse. Along with these are multitudes of Coprolites, appar-

enti J Saarian, resembling in size and form the Ooprolites found in the carbonaceous bedtf on Deep river, and also some imperfect im- pressions of Zamite leaves. Tnese facts Prof. Rogers considers sof- ncient to identify, as one formation, the disconnected tracts of this belt in North Carolina and Virginia, and the great prolonged area of the so-called New Red Sandstoneof Maryland, Pennsylvania, and New Jersey.

As to the geological date of this belt, Prof. Rogers said, that the discovery at various and remote points of its course of Posidonin, OypridfB, and Zainitea, most or all of which are identical with these forms in the eastern middle secondary areas of Virginia and North Carolina, makes it extremely probable that these rocks, formerly referred to the New Red Sandstone, and of late more specially to the Trias, are of Jurassic date, and but little anterior to that of the Coal Rocks of Eastern Virginia.

Prof. Rogers considered the frequent occurrence of Cypridaj hi all these belts as a strong evidence of their Jurassic age. While only a few species of CypridsB, and many of the allied genus Cythe- rina occur in the Silurian and Carboniferous rocks, there is a total absence of these crustacean remains throughout the series of depos- its extending from the base of the Permian to the lower limits of the Odiite. But on entering the latter, the Cypridfo reappear, and become very abundant there, there being no less than twelve spe- cies, known to belong to the Odiite formations of Europe.

Qn comparing the silicified wood, found in the western and east* em belts, Prof. Rogers had found its structure to be the same, and to agree very nearly with the fossils figured by Witham under the name of Peuce Huttonia. As this particular structure does not appear to have been met with below the Lias, and occnrs in that formation, it ftirnishes another argument in favor of the Jurassic age of all these rocks.

Prof. Rogers added that he had not found in the New Red Sand- stone of the Connecticut Valley either the Posidonia or Cypris, al- though he had met with obscure markings which he was inclined to refer to the latter. He had however satisfied himself that one of the plants, from the vicinity of Greenfield in Massachusetts, was identical with the form in the Virginia coal rocks referred to Lyco- podites, and probably Z. Williamsonu; and that among the other very imperfect impressions associated with this was one which he regarded as the leaf of a Zamites.

On the whole, therefore, Prof. Rogers concluded that the addi- tional fossils from the coal-bearing rocks of Virginia and North Carolina served to confirm the conclusion of their being of Jurassic date, and that the fossils thus far foand in the more western beltL and its extension through Pennsylvania and New Jersey, rendered it proper to remove it from the Trias and place it also in the Juras- sic period, a little lower probably than the eastern belt of North Carolina and Virginia; and there could be little doubt, he thought, that the same conclusion would apply to the New Red Sandstone of the Connecticut Valley.

H.

The following extract from a letter addressed by Prof. Rogers to Dr. T. Sterry Hunt, Jnne 8th, 1877, is taken from a volume of the Second Geological Sarvey of Pennsylvania, 1878. Report £, on Azoic Rocks, by T. Sterry Hant, pages 198 and 199.

The sections which I had the pleasure of showing you lately, illustrating the position of the lower Cambrian beds (our Primal conglomerate, etc.) in their contact with the crystalline and meta- morphic rocks of the Blue Ridge in Virginia, form part of a series embracing the results of some forty transverse explorations, made daring and since the Virnia geological survey, at nearly equal distances across the chain, from Harpers Ferry to the North Caro- lina line. In many of these sections the unconformity of the Cam- brian upon and against the crystalline and metamor])hic rocks is nnmistaRable and conspicuous ; the lower members of the Primal being seen to rest on the slope of the Ridge, with northwest undu- lating dips on the edges of the southeastward-dipping older rocks. In other cases the primal beds, thrown into southeast dips in the hills which flank the Blue Ridge, are made to underlie, with more or less approximation to conformity, the older rocks forming the cen- tral mass of the mountain. But even in those instances it is, I think, not difficult to discern the true relations of the strata. As interesting examples of the phenomena referred to, I would men- tion the sections exposed at Vestals, Gregorys, Snickers and Ma* nassas gaps, and Jeremie's Run, in the northern part of the Blue Ridge ; and at Dry Run, Turks, Tye River, Whitens, James River, Point Lookout, Fox Creek and White-top Mountain gaps, in the middle and southwestern prolongation of the chain.'

This letter is of interest as referring to sections, illustrating un- conformity of certain strata, which accompany Prof. Rogers* geo- logical map of the Virginias, edited by Mr. Jed. Ilotchkiss, and pub- lished at the same time with this edition of the Virginia reports.

In the Article on Analyses of Waters of the Principal Mineral Springs of Virginia " —

Page 662, Sweet Springs, Monroe Co., are now colled Sweet Chalybeate."

Page 666, Warm Springs, Bath Co., are now " Warm Sulphur."

Page 667, Alum Spring, now Rockbridge Alum."

In the Article on " Connection of Thermal Springs in Virginia with Anticlinal Axes and Faults " —

Page 681, Sweet Alum Springs are now called Healing Springs," and Bath Springs are now Berkeley Springs."

Page 684, Strickler's Spring, now Rockbridge Baths," and Bofords Gp Springs, now Bine Ridge Springs."

Index. .

Part I.

General Index.

Academy of Natural Sciences, Phila- delphia, % 670. Acidulous springs, 649, 668. Actinocyclus bioctonarios, 734. Actinolite, 291, 469. Actinoptychus bitemarius, 734. Agate, 478. Age of deposit overlying Miocene

marl, 666. Albite, 284. Alkaline springs, 649. Altered rocks in middle secondaty,

Altered rocks of For. I, 461. Altitude of mountain peaks, 416. Alumina in iron ores, 238-242, 309,

401-406, 627-632. Alumina in magnesian and hydraulic

limestones, 231-237,390-401. Alumina in rocks and clay, 70, 283,

Alumina in springs, see Analyses of

springs. Alumina, sulphate, 60, 101, 127, 180,

426, 434. Alumina, sulphide, in springs, 649. Alum earth, 768.

rock, of Jackson's river, 101.

" springs, see Springs. Amber associated with green sand

of New Jersey, 6. American Journal of Science, 666. American Philosophical Soc., 606. Ammonites, 6, 68, 172. Amygdaloid of Thornton's gap, 462.

varieties of, 462. Analyses, see Coal, Iron, Limestone,

Marl, eta

u

Analyses of springs, see Springs. specimens for cabinet proposed, 122.

Analysis not always sufficient to de- termine the value of hydraulic limestone, 94.

Animal deposit in springs, 689.

Animal remains in coal rocks of Eastern Ya., 647, 668.

Anticlinal axes of Great North and Little North mts., 691.

Anticlinal mountain defined, 608. of Peter's mt., 726. valley, including thermal springs, 724.

Anthracite coal, see CoaL

Antimony, 112.

Apocrenic add, 649.

Appalachian chain, identity of the undulations with earthquake waves,

Appalachian chain, origin of the sup- posed subterranean undulations, and manner in which the strata became bent and dislocated, 627.

Appalachian chain, predominance of southeastern dips, 606.

Apparatus for analyzing marl and carbonates in general, 9-11.

Appendix to report for 1837, 186.

Appropriation, continuation of, 644,

Area, 36, 734. " centenaria, 33, 36, 434. idonea,484. incile, 33, 434. protracta, 662. '' stiUiddium, 434.

Arch, Bee Strata.

Ardisan, 717.

rocks of Virginia, note on,

Area of Appalachian zone, 107.

Arsenic, 112.

Artemis, 85, 784.

acetabulum, 88, 434.

Artesian well at Fortress Monroe, character of the materials at dif- ferent depths, 734.

Artesian well, depth attained, 788.

Asbestos, 72, 86, 90, 460, 469. in epidotic rocks, 461. " lignifonn, etc., 464.

Ashraolean Society, 678.

Assistants, arguments for continuing the employment of, 644.

Association of American Geologists and Naturalists, 669, 677, 601, 607,

AsUrte, 887.

undulata, 484. vidna, 484.

Astrea, large spedmen described, (note), 667.

Augite, 71.

Auriferous rocks, see Bocks.

Auroral, 717.

Auroral rodcs, rarity of fossils in,

Auroral rocks, use of the designation in the Table of Formations, 722.

Axes, anticlinal, explanation of, 208. tangential or hori-

zontal force an inadequate cause of, 625.

Axes, anticlinal, theory in regard to elevation of, by M. Elie de Beau- mont, 622.

Axes in For. IX, 860. " " For. IX and X, 226. of Appalachian chain, 624. " " " " analogous

phenomena in other countries, 687.

Axes of Appalachian chain, cunring form of, 621, 630, 631.

Axes of Appalachian chain, date of,

Axes of Appalachian chain, distribu- tion into groups, 617.

Axes of Appalachian chain, great length of, 620.

Axes of Appalachian chain, increas- ing interval between, as we ad- vance northwestward, 624. Axes of Appalachian chain, parallel- ism of, 618, 619, 620, 630. Axes of Appalachian chain, theory of

the formation of, 627, 628-680. Axes of front ridge of Alleghany,

Axes of Massanutten mts., 220.

the Blue Ridge region, 219,

226, 849. Axes of the Valley region, 210, 218,

Axes of Wales, Sir R. Hurchison on,

Axes, synclinal, explanation of, 208. Axis, anticlinal. Warm spring, 719.

at Draper's mt, 228.

White Sulphur springs, 688.

Briery, 369, 860.

" the lowest formation seen in

For. IX, 860. Axis, Kingwood, 862.

" Negro mt., 861.

" of Backbone mt, 860, 859.

'' '' Enobly mt, 848.

'' Laurel hUl, 869, 466.

" " LitUe North mt, 226.

Malvern hiUs, fing., 688.

" Purgatory mt, 222.

'' " Sweet Springs valley, 616.

" Walker's mt, 141.

Warm Springs mt, 174.

" " Will's Creek mt, 847.

plane defined, 609.

" Preston, boundaries of, 868.

synclinal, of Fort Lewis mt,

228, 725 (note). Axis, synclinal, of Fort mt, 728.

Third Hill mts.,

Azotized organic matter in springs,

see Analyses of springs.

Balanidie, 784. Barometer, use of, 198. Barometrical observations of the

heights of mts. proposed, 120. Baryta, carbonate, 97.

'' sulphate, 81, 88, 97, 287,

Basins, see CSoal, etc

Belemnites, 6, 7.

Big coal scam of Monongahela val- ,

fey, dimensions of, '703. Bird'sye maple slate, see Slate. Bittern, absence of, in Brine springs

of Holston valley, 142. Bitumen in coal of Botetourt co.,

Bituminous coal, see Coal. Black flint of Kanawha valley, 878,

Boardof Public Works, 22, 124, 148,

190, 412, 638. Boiling-point thermometer used in

measuring heights of mts., 346. Bog ore, see Iron. Bolanus, 889. Boston Society of Natural History,

Boundaries of ancient sea, H. B.

Sogers on, 166. Boundaries of ancient coast-line, 264,

Boulders of cobble-stone deposit, 710. Boulders, sandstone, 420. Brecda, 472. Brine springs, 142, 649. Bromides in springs, see Analyses of

springs. Bucdnum laequeaturo, 484. Bubr rock, 38, 178. Building material, 132, 178, 479, 491,

497, 606. Building material, Essex co., 81. " " granitic gneiss,

Building material, limestone, 468,

Building material, sandstone, 188,

Building slate of For. X, 183.

Cadent, 717. Calamltes, 183, 661.

arenaceus, 646, 649, 660.

planicostatus, 660.

Suckowii, 660. " Calcareous manures," 41. Calcareous maDurea,Mr.Ruffinon, 19. Calciferous division, 717, 722. Cambrian, 717.

Sir B. Murchlson on, 637,

u u

Candona, 720. Carapace, 766. Carbonaceous strata near Richmond,

Mr. Maclure on, 646. Carbonate of ammonia in mar], 279. " of copper, 464. of lime, crystals of, rcscm*

bling Dog-tooth spar, 34. Carbonate of lime in marls, sec Marls. " in rocks on the

Potomac, 429. Carbonate of lirae in Valley lime- stones, 96. Carbonates, apparatus for analyzing,

Carbonates in springs, see Analyses

of springs. Carbonic acid in springs, see Analyses

of springs. Carbomferous group, 717. Carburetted hydrogen in springs, see

Analyses of springs. Carditas, 436. Cardita planicosta, 18, 666. Cardium, 38.

laequeatum, 671. magnum, 671. quadrans, 671. Caryophyllese, 102. Cascade of Falling Spring creek, 726. Catopterus macrurus, 668. CatskUl Division. 717. Caves in Valley limestone, 97, 764. Cement used for James river canal,

Cenozoic, 717. Chalcedony, 209, 462, 478. Chalk, 439.

absence of, in Virginia and

New Jersey, 6, 17. Chalk, occurrence of, in Europe, 17,

Chalky marl, 271, 426. Chalybeate springs, see Analyses of

springs. Chama, 36, 36, 42, 47, 162, 164, 166,

886, 887. Chama congregata, 88, 889, 434.

corticosa, 434. Chama in Tertiary marl of James

river, 280. Chama, presence of, a guide to vala-

ablc marls, 13, 14.

Character of the flexures in the cUt!- Bions of the Appalachian chain, Charcoal, 445. Chazy DiTision, 717. Chemung Division, 717. Chert, 198, 199, 201, 204, 2ia

" of For. VI, 178. Chlorides in springs, see Analyses of

springs. Chloride of calcium, see Analyses of

springs. Chloride of iron, see Iron.

of magnesia, see Magnesia. Chlorite, 78, 88, 205, 285, 293, 296,

456, 459, 462, 466, 481. Chlorite described, 285. Tcins of, 293. Chloritic sand of £ocene formation,

Chloritic slate of Carter's mt., 466. Chrome iron ore, 46S, 464. Chthonisothcrmal line, 694. Classification and distribution of the older rocks of Germany," Mur- chison and Sedgwick, 640. Classification, Prof. Sedgwick's, used,

Clay, 38, 66.

add, 426, 436. analysis of, 70.

argillaceous, of Eocene forma- tion, 666. Clay associated with infusorial earth,

Clay, calcareous, 260, 429.

containing casts of shells, 446. containing copperas and sul- phur, effect of, on vegetation, 45. Clay containing fossils, 88, 486. . " ferruginous, 126, 260, 426, 428,

436, 448. Clay for bricks, 49, 880. gypseous, 486, 437. in marls, 50, 61, 126, 268, 426. ochreous, 64, 452. pipe, 260, 277, 288. porcelain, 284, 815. rounded masses of, at Os- borne's ferry, 448. Clay, silieeousl 288. sulphate of iron in, 60. sulphurous, 60, 426, 485, 446.

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Cliffs at Stratford and Chantilly,420,

Cliffs at Woodstock, 422. " at Yorktown, 87. fossil shells in, 428.

height of, on Potomac, 428. of Eocene formation, 666. of New river, 842. of Rappahannock, 430. on the Cheat river, 684. Clinton group (For V), 613, 618, 717. Coal, Abraham's creek, 854, 856. adapted to the manufacture of iron, 185. Coal, Allhany and North mt. re- gion, 99. Coal, analyses of , 100, 181, 186, 824,

406<410, 526, 627, 683-635. Coal, anthracite, 87, 98, 94, 98-100.

160, 164,286,824,722. Coal, non-bituminous, near Lcakes-

ville, N. C, 824.

Coal, area of, in Chesterfield, Pow*

hatan, llcnrico, and Goochland,

Coal, area of lower coal measures

south of the Great Kanawha, 541.

Coal, Springfield and Deep run basin,

Coal, Augusta co., 100. basin of Beaver meadow, 618. " Easterner Potomac, 851- Coal basin, explanation of, 347. of Kingwood, 862. " middle, 866-368. " of Mt. Carmel, 869. " Preston, 868. " Western, 868, 869. " basins between Front ridge of Alleghany and Backbone mt., Coal basins of Preston and Monon- galia COS., 859-862, 368, 408, 409. Coal basins. Will's cr. mt., 848. Coal, beds of semi-bituminous, in

neighborhood of iron ore, 96. Coal, Berkeley, analysis of, by H. D.

Rogers, 100. Coal between Big Sewell and Kana- wha, 406. Coal, Big Sandy, 868, 869. Big Sewell mt., 406.

tt tt

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Coal, big vein at PrideTalc, quality of and measurements in, 703,

Coal, bituminous, 27, 28, IIS, 117, 180, 185, 815-327, 386, 880-882, 437-445, 514.

Coal, bituminous, of Botetourt oo.,

Coal, bituminous, of For. XI, not likely to be valuable, 186.

Coal, bituminous, geological rela- tions of, 118.

Coal, bituminous, of Wheeling, 117. Black Heath mine, 68-65. Boyer's mine, 498. Brantzburg, 868. Brushy mt., Stroublcs run, etc.,

Coal, Caropbeirs creek, Kanawha, 379, 881.

Coal, canncl, 366, 490, 610. Catawba creek, 28. Cheat mt, thickness of, 117. Cheat river, 864, 866, 866. " Chesterfield, Powhatan, Gooch- land, and Henrico basins, 583.

Coal, Chesterfield, thickness of seams of, 68, 69.

Coal, Clarksburg, 410. Cumberland oo., 69. Deep run, 66, 446, 686. " Beep run and Springfield pits,

Coal, Difficult creek, 869. diminished thickness of seam below mouth of Kanawha, 618.

Coal, directions to be followed in ex- ploring for, 841, 845.

Coal, Eastern or Potomac basin, 849,

Coal, Eastern or Potomac basin, thickness of scams, 368, 854.

Coal, Elk-Garden tract, 866.

Coal-field near Richmond, R. C. Tay- lor on, 645, 647.

Coal-fields of Chesterfield and Pow- hatan, boundaries of, 480, 482.

Coal from near the Appomattox river, 634.

Coal, geology of bituminous field of the primary region, 62.

Coal, geological position of, at Big Sewell mt, 842.

Coal, great Importance of main seam

on Ohio, 617. Coal, great upper seam, discovery of

the extension of, 641. Coal, Great Kanawha, in vicinity of

salines, 117. Coal, Great Western field, 113-117,

406, 406. Coal, Great Western field, boundaries

of, 116. Coal, Great Western field, lower

group, 484, 487. Coal, Great Western field, order of

succession of rocks of, 116. Coal, Great Western field, sketch of

operations in, 484-486. Coal, Great Western field, structure

and rocks of, 830-347. Coal, Great Western field, thickness

in upper group, 604. Coal, Great Western field, undis-

turbed condition of the strata of,

Coal, Great Western field, upper

group, 485. Coal, gi*eat width of Western basin,

Coal, grouping of seams in Great

Western coal region, 484. Coal, Henrico and Goochland, com- bustible value of, 181. Coal, highest workable scam in Mon- ongalia section, 602. Coal, Hughees creek, 877.

Importance of preserving speci- mens in boring, 61. Coal, impure bituminous, 446.

in Massanutten range, if any,

anthracite, 98. Coal in shaly strata of For. X, 188.

from the Hampshire and Hardy

basins, 407, 408. Coal, Kanawha valley, 874-883, 406,

Coal, Kanawha valley, position and

character of seams, 873, 874. Coal, Keller's or Kelley's creek, 378.

Kingwood basin, boundaries of,

863, 364. Coal, Kingwood basin, middle seam,

Coal, Kingwood basin, upper seams,

(I

Coal, Lewisburg, 186. " Little North mt., 99. lower group, Western field, 485, 489, 490, 493.

Coal, lower group on Ohio river, 506-

Coal, lower shale and eandstone group, 485.

Coal, lowest seam of Potomac basini

Coal measures of Eastern Virginia, referred to Oolite series in England,

Coal measures of England, remarks on, by Rey. Mr. Conybeare, 750.

Coal measures of the Pridevale re- gion, 684.

Coal measures related to Lias pe- riod, 542.

Coal measures, rocks inferior to, in Meadow mt, 872.

Coal, Middle basin, 866, 857.

Midlothian, 64, 69, 571-578. mines in whidi results in re- gard to temperature have been ob- tained, 569.

Montgomery co., 186. Montgomery and Wythe, probiu bly referable to lowest ooal series,

Coal, Morgantown, 498.

Mr. Harvey's estate, 868. Mr. Yandover*s, 854. " Narrow Back, 228. " near Charleston, 882. " Well8villeontheOhio,508.

Coal, north side of James river, 534,

Coal, no true seam of, lower in the series of formations than X, 230.

Coal not to be expected in Massanut- ten ranges, 159.

Coal of Chesterfield, etc., of more re- cent date than that of Great West- em coal measures, 446.

Coal of For. X, 226, 228, 229, 835, 836, 368.

Coal of For. XI, 866-369, 405-410. " " " XI, near Lewisburg,

Coal of For. XII, 340, 342, 487. " " Xm, 348, 845, 488-490, 526, 527.

it

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Coal of For. XIV, 498, 497.

u u XV, 498-604. Coal of Middle secondary, 822, 479.

" " Primary region, 62-69.

" Monongahela valley, position

of eastern margin of, 870. Coal of Monongalia valley, thickness

of, in upper group, 504. Coal of Secondary, 28. " " " mode of mining,

Coal of Westphalia, Europe, 640.

" on Ohio river, 498, 517, 518,

Coal, Oolite, of Eastern Virginia,

Coal, Oolite, of Europe, 646.

possible depth of, near Mid- lothian mine, 69. Coal of Pridevale Co., extent of, 702. Coal, Preston basin, 868. Coal, Prince Edward oo., 69.

ps!eudo>nthracite, 27.

raw, use of, in other oountrics,

Coal rendered lustrous and striated

by attrition, 100. Coal roserobling coke, 827.

Rider's creek, 876.

Rockingham oo., 100.

rocks of Deep river, 766.

Savage river, 853.

seam, Mr. Wickham*s, 63.

" seams at Guyandotte, 519.

" second and third seams of Poto- mac basin, 353. Coal, sections across the Monongalia

valley, 486. Coal, semi-bituminous, 100, HI, 186,

Coal, semi-bituminous, of region im- mediately west of the Valley,

Coal, semi-bituminous, of Catawba,

136, 225. Coal, semi-bituminous, in neighbor- hood of Iron ore, 96, 108, 164,

Coal, Sleepy creek and Third Hill

mt., 226. Coal, Smither's creek, 875. Coal, south aide of James river, 683,

Coal, Stoney riyer, 866. Stockton's seam, 876-878. thin seam soaih of Prince Ed- ward C. H., 827.

Coal, upper group or For. XY., 498. upper series, 410. upper group on Ohio river, 613-

Coal, upper shale and sandstone group, 485.

Coal, Union mine, 66. " vertical section, 379, 383. Vineyard hUl, 379, 880, 881,

Coal, Westemport, 862. " Witcher's creek, 78.

Coast-line, ancient, 166, 264, 266.

Cobble-stone deposit near lUchmond,

Cobble-stone deposit, difficulty in some cases of discriminating be- tween it and older formations, 712.

Cobble-stone deposit, geological posi- tion of, 709, 713.

Cobble-stone deposit not to be con- founded with the pebbly beds re- ferred to the Upper secondary,

Cobble-stones of the Virginia de- posit not striated as in the north- em drift, 711.

Coke from Chesterfield, peculiar char- actor and composition of, 635.

Coke of the neighborhood of James river, character and thickness of, 677, 678.

Coke produced by intrusion of igne ous rocks, 327.

Collections for cabinet, 645.

Column illustrating strata, 276.

Condition of shells in the Tertiary deposits, 33.

Conferva found in sulphureous wa- ters of Yorkshire, Dr. Lankester on (note), 689.

Conferva in sulphur springs, 689.

Conglomerate, 380, 477.

Conglomerate in Middle secondary exposed on James river canal, 318.

Conglomerate in section near Aldie,

Conglomerate of Albemarle co., 85. Briery axis, 860.

It

Conglomerate of coal measurea of

the Cheat river, 688. Conglomerate of Por. X, 183, 351.

" For. XII, 840, 848,

849, 369, 862, 363, 868, 870. Conglomerate of For. XII, forming

the floor of coal measures, 484. Conglomerate of For. XIV, 494. Conglomerates in Middle secondary,

825, 471, 472, 479, 480. Conglomerates, in Upper secondary,

489, 442, 443.' Conglomerates of Blue Ridge, 815,

Conglomerates of Kanawha valley,

Conglomerate of Eingwood xis, 863. Copper, 88, 184, 479.

caution in regard to, 138, Copper, cupreous rock, 87, 88. early mining of, 87, 88. in Middle secondary, not lik ly to be of economical value, 480. Copper, Taylor's mine, 87.

ores, 75, 87, 183, 285, 297.

of Blue Ridge, 134. carbonate, 133, 134, 463, 464, 476, 477, 479, 480. Copper, phosphate, 480.

'' Bulphuret, 87, 138, 480. Copperas, 45, 50, 127, 180, 279, 310,

424, 486, 758. Copperas, means of detection in clay,

Copperas springs, sec Springs. Coprolitcs, 767. Corbulo, 432.

" inequalc, 429. Correspondence in regard to artesian well at Fortress Monroe by Gen. A. A. Humphreys, 733. Correspondence relating to GeoL re- ports, 22, 124, 148, 190, 246, 412, 638, 749. Correspondence relating to Tertiary

of Virginia, 736. Coscinodiscus apiculatus, 734, 736. concavus, 736. disciger, 735. excavatus, 735. gemmifer, 785. giga8,734.

u tc

u

CoscinodiscQB hetcroponiB, 7S6. lineatuB, 786.

marginatus, 786.

" minor, 736.

omphalanthnSf '186.

" perforatus, 786.

radiatuB, 786.

" rodiolatus, 786.

BtriatUB, 786.

" TelatuB, 786.

Crag of England, the, Mr. Ljellon, 89. CraspedodiscuB CoscinodificuB, 786. Crassatella, 86, 42, 887.

capri-craniom, 486, 672.

" Harylandica, 434.

melina, 434, 672.

Crenic acid, 649. Crcpidola, 88, 86, 87, 88, 164, 866.

coBtata, 87, 484. CrctaceouB formation diaclosed in ar- tesian boringB at FortresB Monroe, CucuUea, 486. CucuUea gigantea, 670. " incerta, 670. " onochela, 669, 670. " transversa, 670, 671. Cupreous rock, see Copper. Cyanite, 72, 286, 288, 291, 806, 814,

Oycadites, 666.

Cycads, stumps of, discovered at Bal- timore by Prof. Tyson, 712. Cylindrical markings in rocks of For- mations I and IV, 171, 176. Cypridae, 766, 768. Cytherea, 164, 886. globoBa, 669. " lenticularis, 669. " ovata, 668. Poulsonii, 669. " Sayana, 87. Cytberina, 768.

Denuding action of currents at west- em limits of Eocene, 426.

Denudation in Great Western coal region, 331.

Deposit marl, see Marl.

Deposits near Paris, observations on, by M. Brogniart, 16.

Deposits near Paris, observations on, by M. Cuvier, 16.

u

Devonian, 717.

Diatoms in infusoria of artesian boringB at Fort Monroe identical with those of tho Richmond beds,

Diatoms, list of, from artesian well at Fortress Monroe, 786.

Dictyocha crux, 784.

istaurodon, 786. PonticuluB, 786. Bpecolum, 786.

Diluvial action on Miocene marl, 666. deposit of James river, 269.

Diluvium, 264, 276, 424, 430, 481, 482, 447, 448.

Diluvium of For. I, 461.

Diluvium of the Northern Neck, 420,

Diluvium of the secondary era, 447.

Dimetian rocks of Wales, 722.

Divisions of Appalachian chain de- scribed, 608-606.

Drift from For. I, 449.

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Earthquake in Scotland, 688. of Chili, 686. of Lisbon, 682. of Ullah Bund, 686. Earthquakes, OaUbria, 682.

Mr. Mitchell on, 632. the origin of anUclinal axes, 684, 686. Earthquakes, ware-like motion of the

earth in, 682, 638. Eastern or Potomac coal basin, 862. Echelon, 98, 681, 689. Echinus of green sand deposit, 6. Elevation in Tertiary, 266. Encrini, 86, 94, 102, 106, 172, 178,

180,888,611. Encrini in marble of senate chamber

in Washington, 86. Eocene, 666-668. Eocene, actual superposition of the

Miocene on, 61. Eocene, casts of foBsils in, 666.

crystallized gypsum in, 1 7, 66. definition of term, 16. deposit, thickness of, on James river, 667. Eocene, description of beds of, 66. Eocene, existence of, beneath the Highlands, etc., 67.

in

Eocene, existence of, throughout whole breadth of state, 67.

Eocene, extent and commodioaa po- sition of, on the rivers, 57.

Eocene formation in Eastern Vir- ginia announced, 666.

Eocene formation of Eastern Va., di- rection of, across the state, 666.

Eocene formation of Ya., new fossil shells of, described, 667-678.

Eocene formation, shells contained in clay of, 666.

Eocene formation, the several beds of, 66.

Eocene, fossils peculiar to, 18.

Eocene, gypseous bed forming the upper boundary of, 260.

Eocene, juxtaposition with newer Ter- tiary, 667.

Eocene, limits of, in tracts south of James river, 269, 268.

Eocene, limits of, on the Peninsula,

Eocene marl district, 28, 20, 48. marl, see MarL

Eocene marls of the Peninsula, 128,

Eocene of Alabama, 16, 10. of the Peninsula, 434.

Eocene of Virginia contains some fossils absent from that of Ala- bama, 19.

Eocene of Virginia, geographical po- sition of, 17

Eocene on the Pamunkey near Piping Tree, 17, 25, 48, 61, 66, 67, 68, 60, 129, 160, 268.

Eocene on the Potomac, 24, 125, 126,

128, 184, 185, 150, 174, 176, 196, 204, 209, 485.

Eocene on the Rappahannock, 17, 80,

56, 121, 126, 128, 160, 261, 263,

266, 424, 426. Eocene oyster, 54.

strata at Woodstock, 422. Eocene strata of James river, 48, 61,

65-68, 68, 77-82, 88, 121, 126,

129, 132, 150, 204, 217, 260-262, 266-269, 261.

Eocene Tertiary, extent of, in Vir- ginia, 17.

Eocne, thickness of strata on the Pamunkey, 63.

Eocene, upper boundary of, 260.

western boundary of, 428.

" western boundary, irregular

line of, 426. Epidote, 84, 00, 206, 286, 201, 816,

827, 829, 860, 861, 862, 868. Epidote, crystals of, 286, 462.

in pinkish felspar, 460.

in slates, 298. Epidotic rocks, sec Rocks. Epidotic rocks of Southwest mt., 461,

465, 466. Epidotic rocks, mineral varieties of,

Epidotic rocks, soil of, 468. Epsom salts, 127. Equisetites, 648.

acutus, 640.

Equisetum arundiniformas, 640.

oolumnare, 646, 648, 649,

660, 766. Erosion, 709.

Erroneous application of term Alle- ghany, 26, 110. Essai sur les Soulivcments Juras-

siques," par M. Thurman, 689. "Essay on calcareous manures,*

Estheria, 720, 726. Euodia Barbadensis, 786. Eupodiscus Argus, 786. Exogyra of green sand deposit, 6, 7. Explorations, plans of, for 1841, 640,

Falcated oyster, 6.

"Farmers' Register," 3, 6, 9, 11, 14,

41, 48, 68. Fasciolaria mutabilis, 672.

" rhomboidea, 672. Fault at Augusta springs and Brock's

gap, 228. Fault at Crawford's mt., 226.

" at Fort Lewis mt, 628.

" great extension of line of, into

Tennessee, 728. Fault in the northwest of the Great

Valley, 722, 726. Fault of Draper mt., 727. Faults, 64, 66, 210, 221, 228.

" definition of, 203.

" at Peters's and East River

mts., 688, 624, 726.

Faults, great extent of, west of Val- ley, 160.

Faults in Appalachlaa chain, 616, 616, 617.

Faults in coals east of Blue Ridge, 42,

Faults, lines of; in the Valley, 210. of western margin of the Val- ley, 616.

Feldspar, 70, 71, 72, 88, 90, 293, 296, 810, 818, 826, 829, 466-469, 462,

47a

Feldspar described, 284.

veins of, in beds of gneiss,

Felspathic day, 446. " sand, 448. Filicites yittarioides, 667. Fire brick, 284, 609.

" at Freeman's landing, on

Ohio, 509. Fire clay, 284, 876, 706.

columnar structure of, 677.

of coal measures of the Cheat

river, 684, 691, 692. Fire clay of Pridevale Co., 706.

" stratum of carbonaceous,

Fish scales, 471, 668.

" In bituminous shales, 818. Fissurella, 33, 432.

" catilliformis, 662. Flag stones, 460. Flexure, explanation of use of term,

by Mr. Hopkins, 641. Flexures broken or passing into

faults, 616. Flexures, examples of, in Appala- chian chain, 618. Flexures, character of, in each of the

divisions of Appaiachian chain,

Flexures in the Lewistown valley of

Penn., 618. Flexures, inverted, of Appalachian

chain, 613. Flexures, normal, of Appalachian

chain, 612, 613. Flexures of Appalachian chain, ori- gin of, 627. Flexures of the strata of Appalachian

chain, and law of their gradation

from southeast to northwest, 607.

Flexures, study of, important in in- vestigating geological dynamics,

FUnt, 377, 378, 882, 886.

forming a line of separation between lower and upper coal series, 846, 346.

Flint, hematite, 687.

or homstonc of Kanawha vai- ley, 877.

Flint rock, associated with coal seams,

Fluor spar, 218.

Foraminifene, 734.

Formations bounding the Valley on the west, 224.

Formations exposed at Jackson river,

Formations met with east of the Primary, 437-439.

Formations of series belonging to Appalachian region described by numbers, 176-185, 197-203.

Formations of the Valley, 204, 206. " of Virginia, table of, 717.

Fossil beds in Surrey ca, 42.

flora of eastern and middle belts of Virginia and western belt of North Carolina, dose agreement in, 720.

Fossil impressions in bituniinous shales, 669.

Fossil impressions in For. IV, 176.

Fossil impressions in shales of Mid- dle secondary, 471.

Fossil impressions in slate and sand- stone of Alleghany and North mt. region, 102, 106.

Fossil plants, culmifcrous, 876. of Oolite coal rocks of Eastern Virginia, 648.

Fossil remains of Deep river, N. C, Prof. Emmons on, 766.

Fossil shells, impressions of, 446. impressions of, distinct in Miocene of the Peninsula, 427.

Fossil shells in shale of Middle seo- ondary formation, 824.

Fossil shells of Acquis creek, 426. " of BappahannodE diffs,

Fossil shells, small proportion of oent, on the Peninsula, 668.

u

FofldU, anmdinaoeocB, 876.

" contained in marl of Nansi- mond riTer, 869.

Fossils, difference distinguishing Eo- cene from Jlioccne, 61.

Fossils, disposition of, in Tertiary de- posits, 35.

Fossils from artesian borings at Fort Monroe, 735.

Fossils in clay, 88.

in cobble-stone deposit of Vir- ginia, 709.

Fossils in Eocene strata, 17. " in For. XI, 184. " in green sand, resemblance of, in different localities, 6.

Fossils in limestone of For. VI, 178. in marl of the Peninsula, 433. " in Middle Tertiary of Lower Virginia, 12.

Fossils in shales of Eanawha Talley,

Fossils in Tertiary, disposition of, 85. microscopic, 488. of Middle Secondary, resem- bling the keupcr of Europe, 647.

Fossils of Tertiary, nature of the ma- terials in which they are embed- ded, 16.

Fossils of the coal measures of East- em Virginia, 648-658.

Fossils of For. I, 172. " King's mill, 85. vegetable, in coal measures, 880, 881.

Freestone, 132, 338, 424, 443, 445. " on the Rappahannock, 182. " at the margin of Eocene strata, 424.

Fucoides, 94, 175, 188.

Fucus, 94.

Fulgur carica, 484.

Fuller's earth, 449.

Fttsus, 88. longsevis, 18, 666. parilis, 434. quadricostatus, 484. tctricus, 38.

Galena, see Lead. Galeocerda lateralis, 784. Gallionella sulcata, 784. Garnet, 78, 287, 288.

Garnet slate, see Slato.

Gases in mineral springs, 649-664,- 586, 688-591.

General Assembly of Virginia, acts of, 762.

Genesee division, 717.

Geodes, 66.

Geographical description of Appala- chian chun, 501.

Geographical description of Appala- chian Valley, 603.

Geological column explained, 266,

Geological description of For, I, 167,

Geological description of For. I J, 1C9,

Geological description of For. Ill, 173, 198.

Geological description of For., IV 176, 198.

Geological description of For. V, 177,

Geological description of For. VI,

178, 199.

Geological description of For. VII,

179, 199.

Geological description of For. VIII,

179, 199. Geological description of For. IX,

182, 200.

Geological description of For. X, 183,

Geological description of For. XI,

183, 201.

Geological description of For. XII,

Geological description of For. XlII,

Geological description of For. XIV,

Geological divisions, boundaries of,

Geological divisions of Great Appa- lachian Belt, 602-612.

Geological divisions of North Ameri- ca, Mr. Maclure on, 26.

Geological epoch of Middle Second- ary, 317.

Geological map, see Map.

Geological position of Thermal springs, 580, 581, 683, 684. I Geological Bailway Guide, 788.

Ys2

(4

Geological Relations of the South of Ireland/' by Thomas Weaver, Esq., 689.

Geological Society of Londoni pro- ceedings of, 640, 666.

Geological survey of Maryland, 19. " " " Penn., 184.

mended by Prof. W. B. Rogers in report of committee, 754.

Geological survey, proposed plan of,

Geological surveys of other countries and states, 766.

Geology, first, second, third, fourth, and fifth general divisions of the state, 26-28.

Geology of Blue Ridge, 26, 166.

Holston valley, 140-143. Little North mt, 728. New Jersey, final report on, 40, 606.

Geology of northern district between the Blue Ridge and head of tide,

Geology of region south of James river, 261.

Geology of region west of Blue Ridge,

Geology of southern district east of the Blue Ridge, 281, 282.

Geology of the Pridevale district, I

Geology of t he Valley, 92, 97, 196, 203, 224, 292, 297.

Geology of west flank of Blue Ridge, 88, 89.

Geology, intricacy of, in region west of the Valley, 184.

Geology of counties east of Chesa- peake bay, 643.

Geology of Great Western coal re- gion, 830-335, 484-486.

Gcolo of Great Western coal re- gion, strata comprised in the three lower groups, 486-604.

Geology of Great Western ooal re- gion, For. X, SS6-S86.

Geology of Great Western coal re- gion. For. XI, 886-839.

Geology of Great Western coal re- gion, For. XII, 340-842, 487.

Geology of Great Western ooal re-

gion. For. Xra, 342-847, 487-

Geology of Great WcBtcm coal re- gion, For. XIV, 491-497.

Geology of Great Western coal re- gion. For. XV, 498-604.

Geology of Appalachian ron, in- tricacy of, 194.

Geology of Appalachian region, rocks of the formations from I to Xm described, 197-208.

Geology of Yorkshire, Eng., 649, 655.

Glacial action, 711.

Gneiss, 66, 71, 73, 286, 288, 466,

Gneiss, arenaceous, 290, 816.

" argillaceous, at Greenway,

Gneiss at falls of the Rappahannock,

Gneiss at Petersburg, alternations in dip of, 468.

Gneiss at Richmond, 71.

" " Willis's mt, 290, 291. " " Woods mt., 290. '' chloritic, 469. described, 286. exposures of, on the James, Appomattox, and Rappahannock rivers, 456.

Gneiss, fcldspathic, 290, 816, -827,

458, 482.

Gneiss, granitic, 289, 466.

highly ornamental variety of, Gneiss, homblendic, 290, 827, 458,

459, 481, 482. Gneiss, kyanitic, 290.

" micaceous, 291, 808, 806, 814. of northern district east of Blue Ridge, 465, 458. Gneiss of Pittsylvania co., 290. the northern district cast of the Blue Ridge, geological posi- tion and character of, 466, 456. Gneiss, pseudo, 294, 459, 465.

" quarries of, 71, 288, 289, 290, Gneiss, quartzose, 291, 314.

" rounded form of hill of, 289. " syenitic, 457. " variety of, at Danville, 289. Gneissoid sandstone 465.

Gneissoid sandstone, decomposition of, 296.

Gneissoid sandstone described, 294. " " of Albemarle

CO. as a building material, 295.

Gneissoid sandstone, quarries of, 296.

Gneissoid sandstone used in locks of James River canal, 296.

Gold belt, 719. caution to be observed in re- gard to, 182.

Gold, locality of, in northern Pri- mary district, 469.

Gold mines, 76, 76. of Buckingliam oo., 814. old workings of, 728. quartz, 74, 77, 80, 809. " region, 27, 78, 79, 181. " veins, 79.

Goniatites, 172.

Goniothecium odontella, 736.

Granite, 721.

chloritic, 818. described, 287. epidotic, 818. near Petersburg, 71. stratified, 66. talcose, 826. unstratified, 288. veins of, in gneiss, 467.

Graphical department, 198.

Gravel and cobble- stone deposits of Virginia and the Middle States, cause of formation of, 711.

Gravel deposit, extent of, at Washing- ington, 710.

Gravel deposit near Richmond, 49. of Washington and

Richmond, 709.

Great conglomerate and Conglomer- ate coal group, 717.

Grecnbriar limestone, 717. " shales, 717.

Green sand alternating with chalk in European localities, 6.

Green sand, analyses of, 8.

Green sand as a manure, 6, 8, 18, 14, 67-69, 119.

Green sand deposit of Maryland, 19.

Green sand, discovery of, in £astern Virginia, 8, 11, 768.

Green sand distinguished from greenish clays, 61.

tt

(C M U

Green sand, general aspect of, 7.

Green sand, general occurrence of, in marl beds, 4.

Green sand, geological period of, 6. " " how recognized, 4.

Green sand in blue and yellow marl,

Green sand in deposit overlying Mio- cene shell marl, 666.

Green sand in Eocene marl, 166, 260, 264, 267, 666.

Green sand in Maryland, Prof. Duca- tel on, 19.

Green sand in Miocene marls, 44, 161-166, 166, 267, 886-889, 482.

Green sand ; its effect on grass and clover crops, 8.

Green sand less abundant in Mio- cene than Eocene, 267.

Green sand, localities of, on James river, 4.

Green sand marl not generally con- taining calcareous matter, 7.

Green sand marls, table showing composition of, 60.

Green sand, M. Berthier on, 8.

Green sand, note on the fertilizing efficacy of, 119.

Green sand not found in all Eocene marl, 68.

Green sand, observations on, by Mr. Ed. Ruffln, 16.

Green sand of neighborhood of New- castle, 64.

Green sand of New Jersey, 6, 7, 15,

Green sand of New Jersey, Prof. 11. D. Rogers on, 69, 119.

Green sand of Williamsburg, 4, 18. " York river, 4. on Potomac, 422. " Rappahannock, 424.

Green sand, quantity used per acre as manure, 8.

Green sand, resemblance to chlorite,

Green sand, Seybcrt of Phila. on, 8.

Green sand, value of, on soil of Pine Barren, 9.

Greenstone, see Trap.

Grindstones, 183.

Grit, Shawungunk, 613.

Grits of Chesterfield, etc., 718.

u ct

(I tt

Grita of coalfields of Eastern Vir-

gmio, 645. GryphsBS, 6, 7.

" of grecQ-sand deposit, 6. Gun flint, 439. Gunpowder marl, 7. Gypseous earth, casts of shells in,

Gypsum, 19, 108, 110, 112, 118, 104,

165, 264, 430, 436, 453, 758. Gypsum as a manure, 60, 127-129,

Gypsum associated with green sand

marl, 66-60. Gypsum, aystallized, 66, 260, 427,

Gypsum in Alleghany and North mi.

region, 108. Gypsum in caves, 108. Gypsum in marl, 19, 127, 426, 427. " in slates of For. Vlll, 182. " in valley of the Ilolston,

141, 177, 726. Gypsum of For. VIII, 180, 182, 200. Gypsum, origin of, in Holston val- ley, 141. Gypsum, spiculie of, in cliffs of Bap-

pahannock, 430.

Hamilton division, 717. Ueight of Peak of Otter, 416.

" " White Top mt., 416. neliopelta, 736, Hcterocercal fish, 647. Highest mt peak, 416. History of the early explanations of

the southeasterly dip in the Great

Appalachian valley, 606. Hornblende, 72, 83, 88, 91, 285, 288,

292, 329, 456. Hornblende described, 285. Hornblende in gneiss east of Blue

Hidge, 468. Homstone, 198, 345, 377, 382. Hot-air blast in smelting with raw

coal, 101. Hot4dr blast, M. Berthier on, 136. House of Delegates of Va., 638,

Hudson River division, 717. Hydraulic cement, 216.

" of For. XI, 339. lime, see Lime.

(C

Hydrogen, carburetted, see Analyies

of springs. Hydrcen, sulphuretted, see Analjr*

ses of springs. Hydrogen in thermal springs, 649,

660, 661, 562. Hvdrographic observations advised,

'121. Hydrosulphuret, see Analyses of

springs. Hypogene rocks, 686, 630.

Ideal section, Plate III described,

608, 609. Igneous action on coal, 635, 677, 678. on rocks of the Hid-

die secondary, 479. Igneous action on strata of South- west mt, 466. Igneous rocks, see Rocks. Igneous rocks, absence of, in Appa-

lachian region, 696. Igneous rocks occurring in Middle

secondary, 828, 476. Illustrations of the strata in the

geological column, 276. Infusoria, 439, 450-452, 735. Infusoria, Ehrenbetgs researches in,

Infusorial earth, 733.

'' described, 439, 460.

Infusorial earth, microscopic forms

in, 450. Infusorial deposit first discovered in

older Tertiary of U. &., 439, 460. Infusorial stratum near Richmond,

Infusorial stratum, geological posi- tion of, 451. Infusorial stratum, thickness of,

Inverted flexures, examples of, in

Appalachian chain, 614. Inverted flexures of Little North mt,

Iodides, see Analyses of springs. Iron, carbonate, 495, 693, 694, 697. Iron, effects of, upon soils, Prof.

Hitchcock on, 762. Iron, hydrated peroxide, 207, 208,

220, 487, 489, 627, 682. Iron ore, 36, 38, 66, 79, 102, 108, 117,

132, 168, 161, 163, 169, 172, 174,

179, 181, 185, 192, 219, 221, 243,

832, 839, 843, 844, 346, 858, 724. Iron ore, ADalyses of, 81, 131, 237-

243, 527-532. Iron ore, argillaoeoiu, 376, 381, 388. Iron oi*e associated with cool of

Chesterfield, 131. Iron ore associated with gold veins,

Iron ore associated with red and va- riegated shales, 159. Iron ore, Bath furnace, 242. " " bog, 311, 6V6. '' " brown oxide, 692, 694. " " chrome, 463, 464. Iron ore, composition of, at Crawford

mt., 241. Iron ore, composition of, at Cotopazi

mine, Rockbridge co., 239. Iron oro, composition of, from For-

rer's ftimaoe, Rockingham oo., 288. Iron ore, extent of, in Appalachian

region, 135. Iron ore, fossiliferous, 117, 200, 867,

531, 724. Iron ore. fossiliferous calcareous, in

For. V, 199, 238. Iron ore, geological position of, at

Woodgrove, Cbeat, 695. Iron ore, hematite, 69, 72, 80, 96,

102, 131, 209, 529-530, 685, 691,

694, 723, 724. Iron ore, hematite, of Bear Knob, 209. Iron ore, honeycomb, 96, 344. Iron oro included in black band

shale, 690. Iron ore in neighborhood of semi- bituminous coal, 96. Iron ore, kidney form, 882, 403,

Iron ore, lenticular, 881. limestone ore bed, 691. Iron ore, magnetic, 69, SO, 87, 810-

812, 463-469. Iron ore, magnetic, near Maysville,

Iron ore, magnetic oxide, 810, 812. Iron ore, magnetic oxide, per cent of

metallic iron in, 810. Iron ore, micaceous, 87, 810, 311. " " oxide, 810.

" near Luray, 217. Iron ore, nodular, 201, 208, 854, 856,

u

865, 871, 880, 432, 493, 507, 580* 532, 692.

Iron ore, nodular carbonate, 685. " " numerous beds of, in Ap- palachian r;lon, 185.

Iron ore, ochreous, 809, 811, 812, 628, 580.

Iron ore of Alleghany region, value of, 161.

Iron ore of Big Sandy river, £69. " Buffalo ridge, 87. " " Decker's creek, 871, 372. " " Deep Hollow run. King- wood basin, 367.

Iron ore of Draper's and Lick mta.,

Iron ore of Orayson and Wythe yielding steel by usual process of smelting, 118.

Iron ore of Henry Clay and Green- ville furnace, Cheat, 371.

Iron ore of Limestone ore belt, Cheat,

Iron ore of Mossy creek, Rocking- ham CO., 218.

Iron ore of neighborhood of Morgan- town, 867.

Iron ore of Poplar Camp and Iron mts., 164.

Iron ore of south side of FowcU's ridge, 242.

Iron ore of west side of SLnobly mt,

Iron ore, pipe, 96, 117, 173, 179, 181, 185, 192, 219, 221.

Iron ore, red belt, 685, 700.

Iron ore, rock or sandstone, 689. " " stalactitic, 529. " " use of hoair-bla8t in smelt- ing with raw coal, 136.

Iron ore valuable for smelting, 87.

Iron ores appertaining to For. Ill,

Iron orefl associated with rocks of For. I, 169, 207, 208, 209.

Iron ores at the junction of Fors. Ill and IV, 175, 222, 228, 224.

Iron ores, brown and ochreous of Buckingham co., 311.

Iron ores from the Primarv, com- position of, 627, 628.

Iron ores. Inferior variety in ForS. VIU and IX, 181, 200.

Iron ores in rocks of For. IT, 178, 198.

" " of For. IV, 198.

" " of For. VII, 179,

Iron ores in rocks of For. VIIF, 181,

200, 724.

Iron ores in rocks of For. XI, 185,

201, 389.

Iron ores of For. I, 238, 289, 529,

Iron ores of For. 11, 217, 218, 240,

530, 531. Iron ores of For. Ill, 220, 221, 240-

Iron ores of For. V, 177, 221, 242,

631, 724. Iron ores of For. VII, 237, 242, 248.

" " of For. Xr, 401, 402.

" " of For. XIII, 848, 344, 487,

488, 489, 490. Iron ores of For. XfV, 491, 493, 494,

Iron ores of Alleghany and North mt.

region, 102, 108. Iron ores of Amherst oo., 311.

" " Campbell CO., 311.

" " Franklin oo., 812.

" " " Kingwood basin, 864,

367, 371. Iron ores of Laurel Hill axis, 369,

371, 872. Iron ores of Laurel Hill, chemical

character of, 696. Iron ores of Little Fort valley, 221,

Iron ores of Massanuttcn mt?., 169.

" " the Cheat river, 864.

u t( ci (( geolog- ical position of, 694. Iron ores of the Cheat rirer, heavy

blue, 689. Iron ores of the Cheat river, ponder- ous nodular, 697. Iron ores of the Cheat river, vegeta- ble impressions in, 371. Iron ores of the Cheat river. Big coal

group, 693. Iron ores of the Cheat river, Haines

group, 698. Iron ores of the Cheat river, Martin

group, 686. Iron ores of the Cheat river, Norris

group, 691.

Iron ores of the Cheat river, Snake- den group, 693.

Iron ores of the Cheat river, Strat- ford group, 689.

Iron ores of the Pridevalo Co., 684, 686, 689, 691, 692, 698, 696.

Iron ores of the Pridevale Co., best method of mining, 700.

Iron ores of the Pridevale Co., gen- eral remarks on, 699.

Iron ores of the Valley, 96, 237-243. " " of western coal measures, 401, 403, 404, 405, 486, 487, 488, 491, 494, 501, 681, 632.

Iron, oxide, in rocks, 30, 284, 286, 286, 287, 809, 312.

Iron, oxide, in limestone, 237, 889- 401, 519-526.

Iron, protocarbonate, 839, 372, 487-

Iron, protoxide, 137, 138. protoxide, in green sand, 14. pyrites,76, 84,88,97, 101,173, 180, 290, 292, 804, 309, 381, 393, 400, 402, 444, 466, 460, 469.

Iron pyrites in gneiss, 290. " " in slate, etc., 180, 809.

Iron rock, see Trap.

Iron, silicate, 82, 666.

Iron stone, condition of fossil im- pressions in, 427.

Iron stone near Stevensbui, 479.

Iron, sulphate, in marl beds, 44, 260, 279, 426, 427, 430, 434.

Iron, sulphuret, in crystals, 97, 290. " works at Buckingham C. H., 78. of Shenandoah, 207.

Isocardia fratema, 86, 429, 434.

Jasper of Thornton's gap, 462.

Journal of Academy of Natural Sd- enoes, 636.

Journal of House of Delegates, 749.

Journal of Science, 46.

Journal of Travels in South Amer- ica," Darwin, 634.

Jurassic age of coal-bearing rocks of Va. and N. Carolina, 768.

Jurasso;retnceous, 717.

explanation of

term, 718.

JurasscMM'ctaccous formation in bor- ings at Fort Monroe, 738.

JuraBso -cretaceous, resemblance of, to Wcalden of Europe, 718.

Jurasso-triassic, 717.

" term used for Mid-

dle secondary rocks of Yirginia,

Kaolin, 73, 89, 711. " analysis of, 78. " forming the cement of sand- stone pebbles of Upper secondary,

Keuper, 647, 767.

Keweenian series of northern Michi- gan, 722.

Kidney ore, see Iron.

Kyanite, see Cyanitc.

Lake at Salt Pond mountain, 109. u a ti u height

of, 726. LaminsD of coal in For. X, 1 83. Law of structure of Appalachian

chain, 605, 609. Law of the position of thermal

springs, 592, 694. Leaf-tripoli, 439, 460. Lead, 110, 165.

mines, 139, 216. " of AustinTiUe, 726. Lcd ore, 27, 75, 88, 139, 140, 164,

178, 218. Lead ore, carbonate. 111, 139.

" " cat's tooth, 139.

" " in For. II, 173, 198.

" method used in smelting,

Lead ore, sulphuret, in veins of chalky

limestone, 112. Lead ore, sulphuret, or galena, 88,

111, 139. Lead ore, sulphuret, containing prob- ably antimony and arsenic, 112. Lead ore, wasteful method of mining,

Lead ores, rarious colored, 139. Lead, phosphate, in crystals 189. Lepidodrcndron, 488. Levant, 717. Levis Division, 717. Lias, 642. Lignite, 6, 7, 70, 865, 429, 487, 445,

Lignite assodatcd with green sand,

6,7. Lignite in slate of Upper secondary,

444, 445. Lime as manure, 91, 94.

carbonate, in clay, 70.

in Eocene marls, 166. in iron ores of For.

XI, 401, 402, 404. Lime, carbonate, in limestone from

Louisville, Ky., 237. Lime, carbonate, in limestones of the

Valley, 92, 138, 169, 170, 172, 231. Lime, carbonate, in mineral springs,

see Analyses of springs. Lime, carbonate, in Miocene marls,

151, 165. Lime, carbonate, in oyster shells, 42.

in rock near Lccs-

burg, 477. Lime, carbonate, percentage in rocks

of the southern district, 390, 391. Lime, carbonate, percentage in blue

marls of the Neck, 127. Lime, carbonate, resembling dogtooth

spar, 34. Lime, fibrous carbonate, 429.

" hydraulic, 27, 68, 93, 138, 169,

193, 199, 211, 217, 230, 308, 339,

363, 365, 367, 396, 837, 492, 608,

Lime in soil of Albemarle, Kelson,

and Amherst cos., 91. Lime, phosphate, in oyster shells, 42.

" sulphate, 893, 424, 428, 430,

434, 666. Lime, sulphate, crystals in Eocene

marls, 666. Lime, sulphate, in mineral springs,

see Analyses of springs. Limestone, argillaceous, 201, 357,

862, 721. Limestone a source of fertility in

mountain valleys, 162, 165. Limestone associated- with grey mica

slate, 306. Limestone at Traveller's Rest, 301. caves of the Valley, 97,

Limestone, cherty, 201, 339.

" conglomeritic, 318, 338. Limestone containing grains of bluish

quartz, CabeU's quarry, 805.

limestone east of Southwest and

Green mta., 80. Limestone, Eifel, 640. Eocene, 436. femiginous,36'r, 492,498,

Limestone, foetid, 860.

" for building and agricul- ture, 477. Limestone, fossilifcrous, 94, 102,

103, 105, 108, 178, 198, 861, 863,

Limestone from east of trap dyke,

Rockingham co., 232. Limestone from LouisyiUe, Ky., 237. " " Natural Bridge, 216,

Limestone near lead mines, Wythe

00., 234. Limestone from near Salt Fond mt,

Limestone from the Primary, 619-

Limestone, hydraulic, used in the

Chesapeake and Ohio canal. For.

VI, 216. Limestone, importance of distinguish- ing between magnesian and non-

magnesian, in the manufacture of

lime, 138. Limestone, iotcrniptGd ranges of, in

Fauquier and Loudoun cos., 468. Limestone, lower Appalachian, For.

11,613. limestone, lower, of the Valley, 616. " magnesian, mode of test- ing, 214. Limestone, magnesian, M. Vieat on,

Limestone, marly, 616.

micaceous, 302, 466, 721. micaceous and taloose, of

Middle secondary, 319. Limestone of Alleghany region, 101,

Limestone of Appalachian region,

Limestone of belt east of the Blue

Ridge, 298, 308, 466-470. Limestone of Cheat river, 397.

" " cool measures, 899,

624, 626. Limestone of For. II forming the

It

u

surface of anticlinal valley in neighborhood of theimal springs, Limestone of Kanawha, 876 624. "" '' Eingwood basin, 866, Limestone of Laurel hill axis, 369-

Limestone of Little Levels, 837.

middle coal basin, 868. Middle secondary, 820. Potomac coal basin, 867, 866. Limestone of Preston basin, 369. " " Prideyale Ca,character and geological position of, 704, 705. Limestone of Tertiary, 44.

upper ooal group in valley of Monongalia, 604. Limestone of upper ooal group of

Ohio river, 614-516. Limestone of Westphalia, Europe,

limestone of Weyer*s cave, 94.

OoUtic, 201, 896, 523. Limestone, patches of, Included in strata of slate, kc, 299, 300, 467- limestone quarries, 70, 187, 188, 169, 178, 199, 211, 213-217, 280, 287, 801, 805, 807, 889, 401, 468, 469, 470, 501, 512, 519, 520, 521, 523, 624, 526. limestone, rotten, 817.

sandy, 199, 860, 861, 87a shaly, 199. shelly, 31.

slaty, SOO, 801, 302, 308, 804, 305, 806, 807, 814, 361. Limestone suited for agriculture

470, 477, 616. Limestone, talcose, 132, 819, 466. " thickness of, in upper

ooal group, 504. Limestone used as a flux in iron

works near New Canton, 302. Limestone used for cement for locks

on James river canal, 188. Limestone, use of, on slaty soils,

81,82. Limestones, analyses of, 82, 137, 138, 16il70, 281-287, 890-101, 519-

a It

LimestoncB and slates, absence of, in cobble-stone deposits of Virginia, aocounted for, 710.

Umestoncs and marbles of James river region, 808.

Limestones associated with primary and metamorphic rocks, 460.

Limestones associated with the mica- ceous and taloose rocks of the southern district east of the Blue Ridge, 38-S92.

Limestones associated with taloose and micaceous slates, 806, 466,

Limestones cast of Blue Ridge, 298-

lamestones near Staunton, 137. of Albemarle co., 300. " of For. II, 169-171, 204, 209-217, 231-235, 892-396, 521- 523, 616.

limestone of For. II, from New York, 236.

Limestone, fossil if erous, of For. Ill,

Limestone of For. YI, 178, 236, 896- 896, 687.

Limestones of For. YIII, 180, 200. " " For. VIII, from New York, 237.

Lhnestones of For. XI, 183-186, 887, 838, 839, 360, 860, 861, 862, 870, 89&-899, 623-524, 616.

Limestones of For. XIII, 843, 489.

Limestones of For. XIV, 492, 493, 496, 496, 497.

Limestones of For. XV, 499, 600, 601, 602, 504.

Limestones of Klngwood basin as- sociated with peculiar clajs and shales, 366.

Limestones of the Valley, 27, 96, 137,

Limonite of Pridevale ores, 687,

Limonites, changes in conditions of,

Lower Barren group, 717.

Lower Cambrian, 717.

Lower Carboniferous, (Lower Sub- Carboniferous,) 717.

Lower Coal group or For. XIII, 484, 487-491, 717.

Lower Coal group on Ohio river,

Lower Ilelderberg Division, 717.

" mesozoic, 717. Lower shale and sandstone group, or

For. XIV, 486, 491-497. Lower shale and sandstone group on

Ohio river, 610. Lucina, 888.

anodonta, 87. " spedosa, 662. Lycopodites, uncifoliuB, 646, 668.

WilUamsonis, 766, 768.

Mactras, 88. Mactra oonfraga, 434. dclumbis, 434. modiccUa, 268, 270, 277, 386-

889, 434. Mactra tellinoides, 33. Madrcporite, 881. Magnesia, 212, 216, 810. Magnesia, carbonate, in clay, 70, 71. Magnesia, carbonate, in limestone of

For, XI, 184. Magnesia, carbonate, see Analyses

of springs, limestones, iron ores,

etc. Magnesia in primary rocks, 286, 286. Magnesia, sulphate, see Analyses of

springs. Magnesia, test for, 218, 214. Magnesium, chloride, see Analyses of

springs. Manganese, carbonate, see Analyses

of iron ores. Manganese of Little Fort valley, 221. Manganese ore, 159, 181.

oxide, 169, 174, 628.

Map, geological, 120, 136, 191. " progress of, 646. Map, state, incorrect topography of,

120, 167, 187, 191, 863, 369. Marble, 86, 98, 212, 818, 466, 469,

Marble associated with irregular dip

of strata, 98. Marble columns in senate chamber

at Washington, 86. Marble, crystalline condition of, in

Berkshire, Mass., 606. Marble, dun coloured, 212. Marble east of Southwest and Green

mts., 80.

((

Marble, cncrinal, 86, 719. fine white, 470. grey, 212, 218. in Middle secondary, 318. Marble, micaceotis and talcose, 298,

808, 466, 470. Marble, mottled bluish, 212.

of Albemarle co., 467.

" of Rapid Anne, 467, 468. Marble of Tye riTer suitable for

sculpture, 88. Marble, Potomac, 133, 818, 472. Marble, Potomac, II. D. Rogers on,

Marble, red, of Giles and Scott cos.,

Marble, shaded, of Rockingham oo.,

Marble, white; of Rockbridge co.,

Marcellus Division, 717. Marine formations in vicinity of

Paris, 16. Marginclla, 387. Marl, apparatus for analyzing, 9, 11,

Marl beds, geological period of, 5. Marl, blue, 82, 48, 126, 130, 256-276,

Marl, blue, described, 268. Marl, blue, probable extent of, east- ward, 228, 258. Marl, blue, species of shells found in,

Marl, blue, richest in fossils, 426. Marl, boring for the shelly strata,

advised, 258. Marl, carbonate of lime in, 17, 44,

46-48, 151-166, 172, 279, 42a Marl, deposit or travertine, 27, 172. " Eocene, at Goggins' point, 260. Marl, Eocene, existence of, beneath

the Highlands, 57. Marl, Eocene, extent of, on the riv- ers, 57. Marl, Eocene, of Pennsylvania, 129,

Marl, Eocene, resemblance to gypse- ous strata of Miocene, 129. Marl, Eocene, tract south of James

river, 259-263. Marl, ferruginous, 43.

from the Pamunkcy, 51-55.

Marl geological position of, 264. " green sand in, see Green sand. " gypsum in, 19, 127, 427.

Marl in cliffs on the Blackwater river, 273.

Marl in Prince Edward co., 70.

Marl in region south of Rappahan- nock, 130.

Marl, Mt Pleasant, 30. odor of, 7.

Marl overlying sandstone, irregular line of contact of, with Primary,

Marl, Miocene, limits of, on Penin- sula, 421-425.

Marl, Miocene, of Neck, upper beds rich in sulphates, 426.

Marl, Miocene, overlying the Eocene,

Marl, peroxide of iron in, 46--48.

Marl, pulverulent white and chalky, 43, 46, 127, 180, 271, 426.

Marl, Rose's method for analyzing,

Marl, sulphate of iron in, 45.

Marl, shelly, 17, 80, 252.

Marl, Tertiary, probable extent of, eastward, 255-259.

Marl, value of, in agriculture, 8, 67, 58, 429, 757.

Marl, value of, compared with barn- yard manure, 119.

Marl, yellow, 46, 264-276, 480.

Marl, yellow and gray, hardening of, by exposure, 272.

Marls, analyses of, 8, 19, 31, 42, 46- 48, 60, 151-156, 127, 172, 279,

Marls, cause of color of, 278.

Marls, light colored, fragroentaiy condition of shells in, 271-273.

Marls, light colored, in irregular patches, 274.

Marls of James river, 19, 65, 150.

Marls of Northern Neck, 126, 130,

Marlmg, kinds of shells best suited for, 42.

Matinal, 717.

Measurement of strata at Jackson river, 838.

Measurements of heights by boiling- point therm., 416.

tt i(

u l(

M

MechAnical and chemical agencicB concerned in the production of thermal springs, 686, 692, 694.

Medial Pliocene, incorrect name for formation containing tertiary shells of the Peninsula, 664.

Medina Division, 717.

Melosira sulcata, 736.

Meridian, 717.

Mesozoic, 717, 767.

Mcsozoic coal fields, western edge of, 726.

Metamorphic rocks, sec Rocks.

Mica, 173, 295, 8U0, 803, 402, 424, 466, 458, 469.

Mica described, 284. in Eocene marl, 61. " Meiocene of Peninsula, 427. rocks of Upper secondary,

Mica in rocks of For. XIII, 348.

sandstone of Kagged mt., 88. " talc slate, 292. " the primary rocks, 71-78 466-69, 464-469.

Mica slate, see Slate.

Micaceous iron ore, see Iron ore. limestone, see Limestone.

Microscopic fossils of Europe,

Middle and Lower Cambrian, 717.

Middle coal basin, see Goal.

CamUrian or Auroral group as exposed in the Valley, 720.

Middle Carboniferous (Upper Sub- Carboniferous), 717.

Middle Mountain-belt, 603.

secondary, appertaining to the New Red Sandstone, 642, 766.

Middle secondary, area of, 473, 474. " absence of calcare-

ous matter in southern portion of,

Middle secondary at Rapid Anne river, 468.

Middle secondary, boundaries of, in northern district cast of Blue Ridge, 472-476.

Middle secondary, boundaries of, in southern district, 320-323.

Middle secondary, carbonaceous mat- ter in strata of, 827.

Middle secondary, certain rocks of

Nova Scotia and Nctv Brunswick

analogous to, 819. Middle secondary, character and con- tents of, in noithem district, 476-

Middle secondary, character and con- tents of, in southern district, 828-

Middle secondary, east of Blue Ridge,

color of strata of, 816. Middle secondary, explanation of the

non-existence of limestone pebbles

in, 819, 820. Middle seoondary,cxposurcs on James

river canal, 818. Middle secondary, its prolongation in

Md., 474, 642. Middle secondary, igneous rocks oc- curring in, 328. Middle secondary, general features

of, 471. Middle secondary in Pittsylvania,

Halifax, and Campbell cos., 321,

Middle secondary in Prince Edward,

Cumberland, and Buckingham cos.,

822, 826. Middle secondary, modifying cfifects

of igneous rocks on, 829. Middle secondary, not adjoining Ap- palachian rocks as in Pennsylvania

and Maryland, 818. Middle secondary of southern district

contains no valuable coal, 326, 328,

Middle secondary on James river,

above Warren, 829. Middle secondary, Potomac marble

in, 818. Middle secondary sandstones and

coal measures, 717. Middle secondary strata, fossils iden- tical in northern and southern dis- tricts, 818. Middle secondary, traced on the map,

Middle secondary, western margin of,

474, 475. Middle secondary, uniformity of dip

in, 319. Middle tertiary of Lower Virginia,

discovery of new species of fossils

in, 12.

Middle tertiary, shells of, 667.

Millstone grit, 288.

Millstones, 98, 173.

Mineral resonrces of Appalachian re- gion, 136.

Mineral resources of Hampshire oo.,

Mineral springs, principal ingredients in, 649.

Minerals found in the Valley, 97. " of Willis's mt., 291.

Mines, observations of temperature in, 670-674.

Mines, see Coal, Iron, Copper, etc.

Mining at Pridevale, best mode of, 700, 702.

Miocene division, 717.

" composition of upper beds of, on Neclc, 127.

Miocene, definition of term, 16. " fossil shells of, 41, 438, 484, 661-668, 669-678.

Miocene marl district, 29, 88.

" " general parallelism be- tween the plane of, and that of the rivers, in southern tract, 266.

Miocene marl, see Marl.

of the Peninsula, 426, 427. " " Umits of,

421, 422.

Miocene shell marl, nature and va- rieties of, 41.

Miocene shells most useful in marl- ing, 42.

Miocene stratum on Governor's Hill, Richmond, 60.

Miocene, terrace of, from the Rappa- hannock to the Carolina border,

Miocene, thickness of strata of, 68,

Miocene which overlies the Eocene,

Monoclinal, term defined, 608.

Montgomery buhr, 178.

" Grits and Coal Measures

(Tucdian?), 717.

Muriate of soda, sec Soda.

Names adopted by H. D. and W. B. Rogers for the Paleozoic forma- tions of Penn. and Va., and used in H. D. Rogers's final report

tt

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tl u u

of the Geology of Pennsylvaniai Natica, 38, 888, 431.

perspeetiva, 662. interna, 662. Navicula, 784. New red sandstone related to the

Middle secondary, 642, 766. Niagara Division, 717. Nitrates in caves, derivation of, 768. Nitrogen, see Analyses of springs. in thermal springs, theory of origin of, 696. Norian or Upper Laurentian, 722. Normal ilip defined, 606.

flexure defined, 608. flexures, see Flexures. Nuculie, 88. Nucula iEqualis, 668.

cultclliformis, 667. limatula, 87, 88. media, 668. parva, 668. Numbers marking the Paleozoic for- mations as used in the Virginia and Pennsylvania reports, 717.

Ochre,49, 64, 811,469.

Ochreotts iron, see Iron.

Odontodiscus Uranus, 736.

Oil of vitriol, see Sulphuric acid.

Old Red Sandstone roclss of Europe,

Oliva, 431, 482.

Oncylogonatum carbonarium, 648.

geological structure in Ireland," by Mr. Tliomas Weaver, 689.

" On the classification and distribu- tion of the older rocks of Ger- many," Murchison and Sedgwick,

" On the physical structure and older deposits of Devonshire," by Messrs. Sedgwick and Murchison, 639.

Oolite coal of Europe, vegetable re- mains in, 646.

Oolite coal of India, fossil plants in, resembling those of Virginia coal rocks, 647.

Oolite formations of Europe, 768. " of Yorkshire, Eng., 664.

Oolitic iron ore, 688. period, 642.

((

lie impremioDfl in ssnclstoiie of For. VII, 179, 19. Organic matter in spriogs, ace Anal- yses of springs. Organic remains in For. II, 178. Organization and operations of the

corps of assistants, 589, 640. Origin of the deposit overlying the

miooene shell marl, 664. Oriskany, anticlinal of, 728. BiTlaion, 717. sandstone of New York (For. Vn\ 790. Orthoceras, 68, 178. Ostrea, 87, 88, 887.

" oomprcssirostra, 86, 484, 668. " seUsBformis, 18, 667. sinuoea, 486, 668. Virginica, 42, 484. Oxford clay, 649. Oxide of iron, see Iron. Oxygen, see Analyses of springs. Oyster, 18. djeicr sheU, analysis of, 42.

Paleozoic, 717.

Paleozoic formations, lower; Sedg- wick's classification of, 720. Panopca reflexa, 83, 86. Paving stones, 709. Pebbles and cobble stones of Wash- ington and Richmond, derived from the Appalachian belt, 709. Pebbles in conglomerate of For. X,

Pebbles marking upper boundary of

Eocene, 68. Pebbles of For. I, 447.

source of calcareous, of Po- tomac marble, 472. Peoopteris insignis, 654.

Ifunsteriana, 646, 664. Nebbensis, 664. teneris, 654. Whitbiensis, 646, 668. Pecten, 86, 86, 87, 88, 42, 885, 887, 667, 784.

Jeffersonins, 484. Hadisonius, 484. Peotnneulus, 88, 667.

pulvinatus, 434.

" subovatus, 434.

Pemdan, 768.

M U

Pema, 84,46, 48, 165, 886, 429,488,

Pema maxillata, 85, 428, 429, 483,

Peroxide of iron, see Iron.

springs, marl, eta

Petie dirt, 108, 768.

Petroleum, 117.

Pence Huttonia, 768.

Phosphates, see Analyses of springs.

Pinnularia, 784.

Pipe ore, inferior quality in For. Vni and IX, 200.

Pipe ore, see Iron.

Plaister, see Gypsum.

Plates of fossil shells, description ofl

Flicatula, 887.

Pliocene, 717, 725.

definition of, 16. of Lyell, 666.

Plumbago, 88.

Podosira maculata, 735.

Polir Scheifer, of Bohemia, 450.

Ponent, 717.

Fopulor errors concerning geological divisions, 26, 114.

Porcelain clay. 284.

Porcelain earth, 78, 457, 458.

Portage Division, 717.

PosidonisB, 767.

Poeidonomya BronnU, 766. Keuperi, 647.

mmuta, 766.

Potash, 82, 284, 810.

in clay of Eocene formation,

Potash in green sand, 8, 11, 14.

Potomac division, 604, 610.

Potsdam group, 717.

Potsdam or primal group, note on,

Potteiy, 456, 607.

Predominance of southeastern dips in Appalachian chain, 605.

Pre-meridian, 717.

Primal, 717.

or Potsdam formation, dis- tance from Washington and Rich- mond of, 711.

Primary, origin of cobble-stonea oft at Washington, etc., 709.

u

Primary and mctamorphic rocks of

north region, between Blue Ridge

and head of tide, 465. Primary, definition of term, 15. formation, 16, 71. at Richmond, 442. narrow belt extending along

the eastern bomidaries of, 437-

Primaiy rocks, see Rocks.

separating Chesterfield

coal-field from coal of Springfield

basin, 488. Primary, south of James river, 266. Productos, 106, 172, 180. Profile section, 24, 97. Protocarbonate, see Iron ore. Protogine, 721. Protoxide of iron, 137, 188.

" " ingreen8and,8,14. Pseudo-gneiss, see Gndss. Fterophyllum, 666. Ptilophyllum acutifolium, 666. Purbeck beds, Virginia Sccondaiy

formation corresponding to, 712. Pyrites associated with slates of For.

Vm, 180. Pyrites, see Iron. Pyxidicula actinocyclos, 736. cruciata, 786.

ti

Quarries, see Limestone, Gneiss, etc. Quart*, 70, 71, 72, 76, 84, 89, 90, 97,

209, 291, 296, 803, 305-307, 816,

826-830, 447, 466, 466, 468. Quartz, auriferous, 74, 77, 80, 88, 86,

288, 809, 814, 469. Quartz, beds and veins of, in gneiss

east of Blue Ridge, 468. Quartz described, 288.

" drusy, 462.

" in epidotic rocks, 461. limestone, 891. pellucid, 97.

slate, see Quartzite.

vein, in diif near Archer's cr.,

Quartz with chalcedony, 462. Quartzite, 298, 466, 469, 464, 721. associated with talcose

slates and limestones, 294. Quartzite described, 293. micaceous, 464.

It

Quartdte of Blue Ridge at Thorough*

fare gap, 464. Quartzite of Nelson co., 294. Quaternary, 717. Quebec group, 722.

Railway stations, geology of, 71

Run, solvent power of, 89.

Reconnoissance, object 28.

Red sandstone of the Middle second- ary, 476.

Report of committee on proposed geolccal survey, 754.

Report of geology of New Jersey,

Reports of geology of Pennsylvania and Yirgmia, 605, 717.

'Report on mineral and thermal wa- ters,'* by Dr. Daubeny, 678.

Report, scope of, for 1841, 689.

Report, subjects and plans of, for 1840, 418, 419.

Researches in region east of the Blue Ridge, 642.

Rhombic scales, 658.

Ripple marks, 102.

in sandstones of For. X, 188.

Rocks, action of currents on, 116. areas occupied by Upper sec- ondary, 489-442.

Rocks, arenaceous, from disintegra- ted limestone, 108.

Rocks, auriferous, 74. Azoic, 769.

Rocks bounding the Valley on the west, 224.

Rocks, calcareous, 477.

Rocks, Cambrian and Siluro-Gam- brian, 724, 726.

Rocks, cause of diagonal lamination of, at New river, 116.

Rocks, conglomerate, of Albemarle CO., etc., 86.

Rocks, crystalline, 84.

decomposition of, 91. epidotic, 461, 466, 478. example of 6chclon in, 98.

Rocks exposed in section from Blue Ridge to Cumberland C. H., 312-

Rocks, ferruginous, 380.

It

1M

Bodn forming the Appalachian

chain, 602. Bocks, fo0ailiferou0, of England,

Prof. Phillips on, 68. Rocks, igneous, 76, 205, 216, 282,

295, 327, 329, 677, 678. Bocks, igneous, of Stoney Man, 205.

hi diff at Lick mt., 223. . Bocks inferior to the ooal measures

in Meadow mt., litlle Sewell, etc.,

Rocks in Middle secondary, 828-30,

Bocks, metamorphic, 85, 282, 295,

Bocks, mineral character and com- position of the more important

Bocks of Alleghany and North mt

region, 97-111. Rocks of the Blue Ridge, 89-92. Bocks of Blue Ridge improperly

termed Primary, 84. Rocks (characterized) of For. 1, 167-

169, 197, 198. Rocks (characterized) of For. II,

169-173, 198. Rocks (characterized) of For. Ill,

178-175, 198. Roclcs (characterized) of For. IV,

175-177, 198. Rocks (characterized) of For. Y,

177, 178, 198, 199.

Rocks (characterized) of For. YI,

178, 179, 199.

Rocks (characterized) of For. YII,

179, 199.

Rocks (characterized) of For. Ym,

179-182, 199, 200. Rocks (characterized) of For. IX,

182, 188, 200. Bocks (characterized) of For. X,

188, 200, 201, 885, 336. Rocks (characterized) of For. XI,

183-185, 201, 836-839. Rocks (characterized) of For. XII,

201, 202, 84042.

Rocks (characterized) of For. XIII,

202, 842-847.

Rocks (characterized) of For. XIY,

Rocks (characterized) of For. XY,

Rocks of For. I hi the Yalley, 204. Rocks of For. Ill in contact with

YIII at Crawford mt., 225. Rocks of For. IV at Streckler's gap,

Rocks of For. IV, curious exhibition

of, in Pendleton co., 176. Rocks of For. X on Cheat rirer,

Rocks of Great Flat Top mt., 373. Rocks of Great Western ooal region,

Rocks of Little Sewell and Meadow

mts., 373. Rocks of Massanutten mt. probably

of later origin than those of the

Valley, 98. Rocks of ridges bounding the YaL

ley on the west, 224. Rocks of Southwest district, 111-1 13.

" the Fort Lewis mt, 726. Rocks of the Little North mt, etc.,

Rocks of the Natural Bridge, 725.

" " the VaUey, 92-97. Rocks, primary, 71, 282, 821, 456,

Rocks, primary and metamorphic, of

Blue Ridge, 455-70. Rocks, Bchktose, of Waterf ord, Ire- land, 639. Rocks, sedimentary, 88, 86, 99, 288,

Rocks, sedimentary, igneous action

on, 88. Rocks, steatitio and serpentine, 468. Rocks, variation of dip marking tho

beginning of Great Western se- ries, 108. Rock structure of Panther gap, 728. Roofing slates, 460. Rotten limestone of New Jersey,

etc, 817. Rotten stone, 450.

Salamander found in Salt pond,

Salina Dirision, 717. Salines, gypsum present in, 112. Salines of Great Western region,

Salmes of Holston valley, 112, 142.

S.W. district of SUte, 112.

Bftlt, 110, 118, 142, 166, 878. " alum of Kanawha, US. Salt and gypsum of North fork of

Holston probably referable to Sub-

carb. period, 728. Salt manufacture in Holston valley,

Saltpetre, 108, 764. Salt pond, 109. Salt region of Holston resembling

Cheshire salt rejon of £ng., 112. Salt wells at SaltviUe, 726. Salt wells of Kanawha Talley, 873. Salt wells, proportion of BiUt in Ta-

riouB, 118. Salts, calcareous and magnesian, in

springs, 691. Sand for glass manufacture, 207.

of Miocene, 29.

white felspathic, 448. Sandstone above the coal on the

Ohio, below Wheeling, 616. Sandstone altered, 880.

Upper secondary, areas

occupied by, 489. Sandstone, argillaceous, 84, 89, tOO,

824, 872, 880, 881, 888. Sandstone as a building material, 70,

84, 86, 168, 206, 444, 491, 497. Sandstone assodated with bed of

limestone on Rapid Anne, 468. Sandstone associated with bitumin- ous coal, 63, 66. Sandstone associated with coal near

Parkersbuig, 882. Sandstone associated with ore at

mouth of Savage river, 868. Sandstone at Morgantown, 491, 494. calcareouSi 824, 861, 864,

479, 618.

Sandstone capping Meadow mt, 116. conglomeritie, 826, 842, 862, 446, 487.

Sandstone, curious character of, at George's creek, 826.

Sandstone, dark greenish blue, Am- herst and Albemarle cos., 91.

Sandstone, epidotic, 90.

" feldspathic, 487, 448,

44648, 461, 463, 486, 611, 612, 616. 618.

Sandstone, ferruginous, 31, 260, 422,

480, 482.

Sandstones, flaggy, 488, 489, 493, 501 Sandstone, fossiliferous, 106, 261. gneisBoid, 294, 466, 469, 460, 466, 470. Sandstone, grey flaggy, of Hinton,

Sandstone, igneous action on, 88, 84. . micaceous, 188, 200, 201, 296, 824, 886, 839, 858, 477, 486, 489, 492, 494-496, 600-02, 618. Sandstone, micaceous, at western

limit of Eocene tertiary, 260. Sandstone, new red, of Europe, 685. of Alleghany and North mt. region, 101. Sandstone of foot-hills west of Blue

Ridge, 167. Sandstone of For. I, 168, 169, 197,

204, 206, 208. Sandstone of For. I, jointed struc- ture in, 167, 168. Sandstone of For. Ill, 178-176, 198. " of For. IV, 176, 198, 220, 587, 616. Sandstone of For. Y, 177, 198. For. VII, 179, 199. " For. VIII, 199. " For. IX, 182. 200. " " For. X, 188, 200, 228,

Sandstones of For. XI, 201. For. XII, 201. valley, 487. Sandstones of For. XIH, 202, 487-

Sandstones of For. XIV, 491-497. " For. XV, 600-608.

Jackson river, anti-

clinal, 728. Sandstones of Kanawha valley, 874,

Sandstone of lower shale and sand- stone group, 486, 610, 518. Sandstones of Ohio river, 506-51 3. Orange co., 182. " Secondary, insulated

locality of, in the bed of Nottoway river, 261. Sandstone of the Middle secondary,

281, 471. Sandstone of Upper secondaiy, 440 446, 446.

It (I

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Sandstone of Wann Spring mt, lOS. western flank of Blue Ridge, geological position of, 168. Sandstone overlying the coal near

Guyandotte, 519. Sandstones overlying thei Primary rocks along their eastern boundary, Sandstone, probably below the Eo- cene strata toward the east, 425. Sandstone, quarries of, 70, &i, 296,

296, 874, 448, 444, 512. Sandstone quarry, Balcony falls, 207. red, 86, 98. resembling millstone grit, Sandstone, schistose, 89.

sbaly, 857, 492, 500. sitictous, 228, 818, 882, Sandstones, slaty, 90, 198, 227, 826, 340, 874, 876, 445, 478, 488, 514, Sandstone, thickness of, at Freestone

point, PotomaCf 440. Sandstone, used in manufacture of

firebrick, 86. Sandstone, yitreous, 205.

yellow, micaceous, 876. Saurians, 766. Saurian teeth, 647, 668. Scalent, 717. Scallops, see Oysters. Schist, 83, 86, 87, 88. micaceous, 84. siliceous, 84. talcose, 81, 84, 86. Schistose rocks, of Waterford, Ire- land, flexure in, 689. Schori, 72, 286, 291.

described, 286. Scolithus, 718.

linearis, 709. Secondary, bituminous coal region

of, 28, 62. Secondary, definition of term, 16. formation, boundaries of, 820, 823. Secondary of New Jersey absent in marl region traversed by the largo rivers of Virginia, 150. Secondary, igneous rocks of, 828, 880. of Europe, 15.

l(

M

Secondai7 of New Jersey, 17, 766. " south district cast of

Blue Ridge, 815.

Secondary, on Appamatox river, 261.

sandstone, forming the

western limit of the TerUary, 420.

Secondary, see Upper and Lower secondary.

Section across the Monongalia val- ley, 486-504.

Section across the Sweet Spring val* ley, 587.

Section at Pridevale, 697.

Stockton*s steam mill, Smither's creek, 876, 876.

Section at Wheeling hill, near nation- al road, 514.

Section crossing Middle secondary formation, 824.

Section from Ashby's gap to Front ridge of the Alleghany mt., 628.

Section from Bath across Cacapon mt., error in reduction of, 590.

Section from fiellfield to Abbeyville described, 482.

Section from Bellfield to Charlotte C. H. described, 481.

Section from Blue Ridge at Tye river gap to Cumberland C. H. described,

Section from Brancsville to Lcesburg described, 476-477.

Section from Elkton to Warrenton described, 478.

Section from Fairfax C. H. to Aldie described, 477.

Section from Falling cr. to Cumber- land C. H. described, 481.

Section from Fork meeting-house to Culpeper 0. H. described, 478.

Section from Petersburg to three miles beyond Ligontown, on the Appomattox, described, 481.

Section from Poplar Camp mt to the commencement of coal rocks, north- west of Abb's valley, described,

Section from Prince Edward C. II. to the Blue Ridge described, 481.

Section from South fork of Roanoke river to base of Peters' mt, near Union, 628.

Section from south of Petersburg to

?98

Prince Edward C. H. described, Section from South mt, Penn., to

Chestnut ridge, 622. Section from the mouth of Little

Bearer rirer, Penn., to mouth of

Big Sandy, on Kentucky line, de- scribed, 604. Section from Warminster to Walker*s

ford described, 801-807. Section from Weldon, N. C, to Hali- fax C. H. described, 482. Section, ideal, in Appalachian ron,

60S. Section in cool near Crab creek, Ohio

river, 619. Section in Formation XI, 837.

mine near Jacksonville,

Section in upper coal group, or For.,

XV, 498. Section, lower coal group, on the

Ohio, described, 60tt, 607. Section near Wheeling, upper coal

group, 613. Section of lower shale and sandstone

in River hill, Ohio river, 611. Section of valley of Shockoe creek

described, 463. Section of Vineyard hill, vertical,

Section on Ohio river above the

mouth of Little Beaver, 606-607. Section on Ohio river, near Wclls-

ville, 608-610. Section, profile, description of, 187. through the White Sulphur

springs, example of flexure, 688. Section, through Wilsons thermal '

and across Garden mt, example of

flexure, 689. Sections across Appalachian chain,

Sections embodied In the general

profile section, from Hampton.

Koads to Guyandotte, on the Ohio,

Sections from geological report by

Sir H. Do la Beche, 639. Sections from Murchison's Siluria,'*

Sections illustrating flexure, 686, 687,

690, 691.

Sections in coal and iron ore of the

Pridevale Co., 682, 701. Sections in south of England, by Dr.

Fitton, 641. Sections planned between Blue Ridge

and head of tide, norUiem district,

Sections proposed, 24, 121. Sedimentary rocks, see Rocks. Selenite, 97, 117, 127, 180,260, 427,

Semipal, 489, 462. Serai formation, 688, 717. Serpentine, 296, 297, 469, 464.

" rock, quarries of, Fairfax

CO., 463. Scrpula, 42, 47, 481.

granifera, 434, Shale, adapted foi* the manufacture

of pottery, 607. Shale, argillaceous, 201, 888, 889,

866, 869, 863, 878, 487-493, 495,

499, 600. Shale associated with nodular Iron

ore, 686. Shale, bituminous, 181, 816, 316, 818,

828, 829, 830, 832, 886, 887, 842,

846, 860, 868, 376, 880, 448, 490,

492, 498, 494, 499, 608, 607, 616. Shale, bituminous, caution in rard

to search for copper in, 183. Shale, calcareous, 839, 844, 876, 479,

486, 614, 616, 641. Shale, calcareous, associated with

iron ore of For. V, 177. Shale, carbonaceous, 106, 2S7, 824,

826, 827, 881, 614. Shale, containing nodular iron ore,

Shale, copperas and alum in, 200.

fossiliferous, 866, 376, 877,

Shale, in Groat Western coal region,

Shale, micaceous, 876, 492, 497, 600,

Shale, ochreous, of For. IV, 176. red, of Bull Run mt, 133. sandy, 607, 60S, 611. siliceous, 864, 877, 882, 496. slaty, 876. Shales, bituminous, of Upper second-

ary, 446.

u

it tl a It

iSbalcfl, calcareouB, xd N. Peon., andMd., 818.

Shales, Greenbriar, 111. of For. II, 206. " For. V, 177, 224. " For. VI, 178. For. XI, remarkable varie- ty of color and crumbly texture of,

Shales of For. XIII, 487, 488, 489,

Shales of For. XIV, 491, 492, 498, 497 498.

Shales' of For. XY, 499, 600, 501, 502, 508.

Shales of Kanawha Talley, 87S, 876. the Middle secondary For.,

Shales of Upper subcarboniferoos at Hinton, 725.

Shales on Ohio river, 510, 518.

Sharks* teeth, 461, 453.

in artesian borings at

Fort Monroe, 783.

Shawungunk grit, 613, 616.

Shell marl, see HarL

Shells, action of sulphates on, 50. casts of, in limestone, 105. casts of, in Miocene marl, 49. change in the species in pass- ing from the Eocene to the Mio- cene, 267.

Shells, condition of, in Tertiary, 83.

Shells in banks of Potomac, 429,

Shells in banks of Rappahannock,

Shells in limestone, 178. in Miocene, 49, 725. " in Tertiary marl, the number examined, 280.

Shells, Miocene and Eocene, not be- fore described, 669, 672.

Shells most useful in marling, 42. new fossil, of the Eocene, 667-

Shells, number of species, on Penin- sula, 39.

Shells of Miocene formation, 661, 662, 668.

Silica, 8, 73, 137, 138, 169, 170, 184, 185, 186, 283.

Silica in clay, 70.

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Siliciain hydraulic limestone, 280

237, 889, 401, 519, 526. Silica in iron ore, 401, 405, 527, 582. in oyster shells, 42. see Analyses of springs. Silicate of iron and pcrtash, 11, 17,

Silicate of iron in Eocene formation,

Silicate of iron, see Iron. Sildous sandstone of Kanawha coal

measures, 882, Silicified wood, 768. ''Silliman's Journal," 42, 678, 664. Silurian, 717.

" of Wales, Sir R. Muichison

on, 640. Siluro-Cambrian, or Upper Cambrian,

Siluro-Cambrian slates, extent of,

SUver,* 75.

Sinks in Miocene marl region, 82. Slate, argillaceous, 74, 89, 182, 198,

292, 300, 813, 826, 867, 445, 448,

460, 469. Slate at Warrcnton, 465.

belt of Massanuttcn mts., 218.

bituminous, 387, 340.

black wafery, having the ap- pearance of coal shales, 479. Slate, carbonaceous, 368.

calcareous, 171, 198, 204, 824,

Slate, chlorite, 74f 75, 88, 816, 459,

460, 465, 466, 469. Slate, conglomcritic, 826.

" epidotic, 465.

" fossiUfcrous, 105, 857, 517.

" garnet, 74, 78, 80.

green, 108.

greenstone, 813.

hornblende, 814, 816, 829, 455,

468, 481. Slate, iron pyrites in, 101.

mica, described, 291. " principal belt of, 291. '' soils of, 292. micaceous, 74, 78, 182, 291, 294, 299, 300, 801, 302, 808, 304, 805, 807, 810, 312, 814, 316, 816, 822, 326, 446, 456, 458, 460, 465,

469, 476, 520.

tt tl tt tt

tt U M M U

Slate, micaoeooB garnet or " birds-eye

maple," 78. Slate of Meadow int., 116. in Augusta oo., 174. pyritous, 99, 101, 141, 180. quarriea of, 460. quartz, see Quartdte. red, 86, 108.

" rocks, west of Southwest and

Bull Run mta., 460. Slate, roofing, 79.

siliceous, 78, 84, 227, 869, 872.

soft blackish, 824.

steatitic, 298, 459, 460.

tolcose, 75, 84, 292, 293, 294,

297, 299, 801, 304, 806, 810, 814,

466, 460, 468, 528. Slate used as an oil stone, 869.

useful for road beds, 106.

Tegetable impressions in, 102.

" varieticfl described, 291-294. Slates and grits of coal field of

Eastern Ya., 646. Slates associated with the gneiss east

of Blue Ridge, 456. Slates, micaceous, of Upper second- ary, 446. Slates of For. I, 168, 206, 208.

u M M ti nitgpgj iy proximi- ty to igneous rocks, 206. Slates of For. in, 175, 209, 210, 218,

218, 219, 222, 228, 613. SUtes of For. YlII, 17-1S1, 199,

221, 224. Slates of For. IX, 180, 188, 200, 228,

Slates of For. XIII, 202.

Alleghany region, 98, 99,

Slates of eastern district, minerals

associated with, 469. Slates of ETmgton, 721.

" Fort Lewis mt., 223.

Massanutten range, 169.

region east of Blue Ridge,

Slates of Southwest mt., 469, 719.

" " the Valley, 92, 93.

" Upper scoondary, 446.

" western coal field, 882, 840,

Slates, Siluroambrian, 722.

suitable for buUding, 78, 479.

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Slates, useful for fiigginga, etc, 460. Soapstone, 27, 79, 297, 814, 469, 482. of northern district east of Blue Ridge, 459. Soapstone (3 Vermont, 87.

rocks, described, 296. Bteatitic, 86, 286. variety of, near Boydton, Society of Natural History, Boston,

Soda, caustic, see Analyses of springs. muriate, from Kanawha wells, Soda, see Analyses of springs. Sodium, see Analyses of springs. Soil, ferruginous, of Goochland, 72. of For. Ill, productiveness of, Soil of Northern Neck, 420. Soils, certain red, not productiye,

Soils derived from mica slate, 292. effect of certain sulphates on, Soils from slates of For. VIII, 182. of Culpcper, Orange, etc., IZSL " epidote rocks, 463. " For. V, 221. " For. XIII, 843. " southern district, east of Blue Ridge, 91, 316. Soils of For. XI, productive, 185. " the primary region, 72. slates east of Blue Ridge, Soils of the northwest portion of the

state, 541. Soils of the primary region, color of,

Soils, presence of limestone rodcs no indication of calcareous matter in, 94, 188. Soils, red, of Bull Run mt., 183.

value of gypsum on, 129. Spar, calcareous, 81, 92, 271, 800,

302, 898, 467. Spar, containing crystals of galena,

Spar, fluor, 218. Spirifers, 172, 180. Spring, Dibbreirs, 226, 395, 561. BidLSon sulphur, 661.

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Spring, Grey sulphur, 106, 109, 894,

Howard's Lick, 661. Humphrey's, 661. McHenry'B thermal, 662, 681. near Milfoid, 684, 724. near Williamsburg, analysis of, 40.

Spring, New Red, or Champagne cha- lybeate, 668.

Spring, Old Red, 664. Preston's, 664. Sweet, or Field, 664. " Wilson's therinal, 663, 681, 689, 690.

Springs, absence of bittern in the brines of Holston yalley, 142.

Springs, acidulous, 649. alkaline, 649. alum, 668, 669. " ammonia in, 40. amount of combined gas in,

Springs, analyses of, 40, 649-664,

Springs, Blue sulphur, 106, 668. brine, of Holston valley, sup- posed origin of, 142.

Springs, Brinkley's, 668, 669. cause of color of, 107, 689. " chalybeate and sulphurous, of slates of Alleghany region, 99, 101, 106.

Springs, classification of, 649. hot, 666. chalybeate, 666. " in For. IH, 178. mean temperature of air at,

Springs, mineral and thermal, Dr. Daubeny on, 678.

Springs, mineral, of For. YIII, 182. near Wardensville, 684. of Alleghany and North mt. region, 101, 104, 106, 107.

Springs of Miocene marl district, al- lied in character to those of the limestone of other regions, 89.

Springs of Shannondale, 101, 173. principal ingredients in min- eral, 649.

rings. Prof. Bischoff on tempera- ture of, 679.

Springs, Prof. Forbes on temperature of, 679.

Springs, Salt sulphur, 106, 108, 109,

sulphuretted, 27, 99, 101, 106, 107, 180, 649.

Springs, sulphuretted, of For. YIII,

Springs, table of temperatures of,

Springs, Sweet, 104, 107, 111, 229, 621, 688, 726.

Springs, thermal, 103, 106, 108, 660. " " at junction of Hypo-

gene rocks with Appaladiian, 686.

Springs, thermal, catalogue of. 680-

Springs, thermal, definition of by Profs. Bischoff and Daubeny, 678.

Springs, thermal, geological position, etc, of, 680-584.

Springs, thermal, of Appalachian chfdn, 678.

Springs, thermal, of Brown's mt,

Springs, thermal, of Europe, 577. " position of, in Sweet

Springs yalley, 692, 726.

Springs, thermal. Prof. Phillips on cause of, 596.

Springs, Yellow sulphur, 668.

Stages to Healing springs, etc., 724.

Stalactites, 764, 766.

Stalactitic ore, see Iron.

Stalagmites, 764, 766.

State cabinet, 122, 193. " mineral resources of southwest- em district of, 111-118.

Staurotide, 293.

Steaschist, 74, 79, 721.

Steatite, 286, 299, 812, 468, 721. chloritic, 88. described, 286. talcose, 286.

Steatitic rocks, of Fluvanna and Loui- sa COS., 468.

Stephanopyxis apiculata, 786. Diadema, 736.

Stigmaria, 646.

Stone used in buildings at Washing- ton, 443.

Strata above Hull's creek, Northum- berland CO., 438.

4t

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t( tl

Strata, arched, 102.

Hrown*8int., 177. of For. IV., 176. Great North mt, Strata, arch of, at Balcony falls, 89.

44 14 44 44 CUftOIl FOIC, 108,

276, 728.

Strata, arch of, at pasts of Calf Pas- ture river through North mt., 103.

Strata at Brock's gap, 224. " Cow Pasture hills, 181. " Draper's mt., 228.

LitUe North mt, 224, 225. Savage mt., 848. '' Warm Sprmg ridge, 690. basin-shaped arrangement of, 173, 174, 181.

Strata, caution against identifying names of, with those of Europe,

Strata, character and contents of Up- per seooudary, 442-449.

Strata, character and contents of Middle secondary and associated trap, 475-480.

Strata, column representing, 264.

Strata comprising three lower groups of Great Western coal region,

Strata, condition of, in which obser- vations relating to subterranean temperature were made, 570.

Strata containing fossil shells, 668.

Strata, diagonal lamination of, 116.

Strata, diagonal lamination of, gen- eral among sandstones of the west,

Strata, definition of terms relating to, 202, 203.

Strata, description of, on Peninsula,

Strata, direction of dip in Great Western coal region, 888, 484-486.

Strata, dip of, in location of thermal springs, 586.

Strata, direction of strike of, in Ap- palacian chain, 619.

Strata, dislocation of, at Crawford's mt., 225.

Strata, dislocation of, in region west of the Valley, 159.

Strau dislocations of, 616-617.

Strata, dislocations of, at Bmshj

ridge, 624. Strata displayed on the Ohio, 504,

Strata, disturbance of, 97. Strata, Echelon arrangement of, 98,

Strata, Eocene of James river, 66.

of the Famunkey, 51. of the Penhisula, 123-

Strata exposed at Rocketts, 448. Strata exposed by denudation, 831,

Strata exposed in ravines in Tertiary

marl region, 264. Strata, faults m, 160, 203, 225, 228. Strata, flexures of, in Appalachian

chain, 608. Strata, folded, 586. Strata in For. XI on Potomac, 837,

Strata, geological position of, on

Kanawha, 888. Strata, greater thickness of, between

lower and upper coal series of

For. XIII, 845. Strata included in southern district

of Middle secondary, 824. Strata in coal of Kanawha valley,

Strata in For. XIV, 494.

in Miocene of the Neck, 427. in rocks of For. VII, 179.

" in section across Monongalia

valley, 486. Strata in Tertiary near Richmond,

Strata, inversion of, at Little North

mt, 224, 225. Strata, inversion of, in Appalachian

Cham, 608. Strata, inverted at Clifton Forge,

Strata in which salines occur, 114. Strata, irregularity of, between Sec- ondary and Tertiary, 261, 262. Strata, law of the gradation of their

flexures from S. E. to N. £. in Ap- palachian cluun, 607. Strata marking the position of tbei

mal springs of Europe, 577. Strata, Miocene, 126.

Strata, nratebility of, in upper ooal

groap, 608. Strata near Portsmouth, 259.

Strata, oblique inflection of, the reg- ular form of anticlinal axes,

Strata of Biggs's mt, 689.

" " Brock8 gap, 224,

" Catawba and Fort Lewis

mts, 222. Strata of ooal basins of Eastern Vir>

ginia, 645. Strata of coal roeamires approadiing

the Ohio, 832, 888. Strata of Eocene of Penlnanla, 434. Strata of gravel and cobble-stones,

Strata of Great Western coal field,

114, 350-851. Strata of Massanutten ranges, 168,

Strata of Middle secondary, 828. Strata of region south of James

river, 268-276. Strata of sand and clay overlaying

beds of marl, 275. StraU of South West mt., 466.

" " the Allegheny mt., 588.

" the Middle secondary, cast

of the Blue Ridge, 471. Strata of the Sweet Springs valley,

StraU on Ohio river, 504, 505.

the Potomac, 428-430, 485.

Potomac associated with

infusoria, 451, 462. Strata on the Rappahannock, 480-

Strata, origin of undulations of, in

Appalachian chain, 881. Strata, position of, preventing the

occurrence of thermals in Sweet

Spring valley, 698. Strata, remarkable exposure of, in

Ilampshire co., 117. Strata, synclinal basin of Ohio river,

described, 882, 888. Strata, terms used in describing,

Strata, theory of elevation of, in Ap- palachian chain, 624-680. Strata, thickness of Miocene, 68, 54.

Strata, thickness of, nearWeetenw

port, 883. Strata, Upper secondary, 440-448. Strata, variation of dips of, marking

beginning of Great Western seriea,

Strata west of the Blue Ridge, oce- anic origin of, 166. Structure and principal rocks of tho

Great Western coal region, 830. Structure of Appalachian chain, 608,

Structure of Appalachian chain. Prof.

Hitchcock on, 606. Structure of the Wealden formation.

Dr. Fitton on, 640, 641. Subcarboniferous period of the salt

and gypsum deposits of the Hol-

ston north fork, 728. Suggans, miners' name for nodules

of iron ore, 688. Subterranean gases, action of, 627,

Subterranean undulations, 627. Sulphate of baryta, see Baryta. " iron in clays, 50. '' iron in mari beds, 44, 45,

260, 279. Sulphate of iron, see Iron. Sulphate of lime, crystals of, in

Eocene, 666. Sulphate of lime in green sand marl,

Sulphate of lime, see Lime.

" magnesia, see Magnesia. Sulphates in cliffs of Rappahannoc]

Sulphates in springs, see Analyses of

springs. Solphides in springs, see Analyses of

springs. Sulphuret of iron, 97. Sulphuret of iron in cool of Ohio

river, 507. Sulphur in clay, 50. Sulphur in Miocene marl, 45, 50, 127,

426, 480, 484. Sulphuric add a test for magnesia in

limestones, 214. Sulphuric add the cause of the dc-

strucUon of shelly matter in marls,

Sulphurous springF, 549.

fittTgent, 717.

Survey, act autborizbf, 28, 762.

Suirey, chemical department of, 192,

Surrey, diemical details of, 384-410.

Surrey, chemical inquiries connected with, 186.

Survey, completion and preparation of final report of, 643-646.

Survey, delays in prosecution Of, 149.

Survey, details not contemplated in annual reports of, 126.

Survey, diflSculties often encountered in geological explorations in, 157.

Survey, graphical department of, 187, 193, 416.

Survey in North Western district,

Survey, laboratory work of, 186, 192. money expended on, 418. number and extent of the re- sults of, 648.

Survey of New York, names of for- mations used in, 717.

Survey of Fenn., names of forma- tions adopted in, 717.

Survey, operations of, in western coal field, 330, 484, 486.

Survey, operations of, in Appalachian region, 641-543.

Survey, operations of, in northwest- cm district, 383.

Survey, operations of, in region west of Oreenbrier river, and in valley of Kanawha, 872-884.

Survey, organization of corps of as- sistants for 1840, 413.

Survey, organization of corps for 1841,639-540.

Survey, plans of operations for, 120, 156, 191-193, 260, 281-283, 413- 418, 453-456.

Survey, progress of, to 1841, 417-

Survey, proposal of, by Hon. P. A. Browne, in letter to Gov. Floyd,

Survey, report of committee on, 754. tasks allotted to assistants, year 1839, 248.

Survey, time required for completion of, 148, 643.

Survey, topographical branch of, 120.

Sosqudumna division of Appalachiaa

belt, 604, 610. Syenite, 721.

" described, 288.

homblendic, 289.

of Harris' branch, James

river, 303. Syenite, porphyritic, 318. Synclinal basin of Ohio river, 382. '' basin of Catawba and Fort

Lewis mts., 725, 726. Synclinal basin of the Massanutten

mts., 722. Synclinal mt. defined, 608. Synedra Ulna, 786. SyStephania Corona, 786.

TaBniopteris latifolia, 653.

'' magnifolia, 646, 661,

652, 658. Tieniopteris major, 653.

Bcitominea, 646, 651.

662, 668. Tsniopteris vittata, 646, 651, 652,

Talc, 83, 285, 288, 291, 293, 801,

306, 310, 466, 459, 462, 466, 467,

Talc described, 285. Talcose limestone, see limestone, serpentine, 464. slate, 468, 464. Talc slate, described, 292. Taunus chain of mts., structure of,

similar to that of Appalachian belt,

Technical terms, explanation of, 202. TellinaB, 33.

Temperature in coal mines of East- cm Virginia, 569-674. Temperature in shafts dthcr just

completed or in progress, 571, 578,

Temperature ; law of its increase as

we descend beneath the surface of

the earth, 569, 574. Temperature, observations of, at dif-

f crent depths, in mines actually or

but lately in operation, 570. Temperature of air at springs, 582-

Temperature of air at Warm springs

and at Richmond, table of, 566.

Tempentare of Bprings, 666, 682-

Temperature of springs in Appala- chian chain, 678, 6V9.

Tcrebratula, 102, 106, 172, 176, 180.

Terms used in describing structure, 608, 609.

Terraces of hilis near Kanawha,

Terrace structure at Vineyard lull,

Tertiary formation, 717.

adjoining Primary on the east, 254.

Tertiary, age of American, 664. as described by Mr. Con- rad, 12.

Tertiaiy, borings in, recommended,

Tertiary, boundaries of, 28, 29, 251,

Tertiary clay containing casta of shells, 446.

Tertiary difls on York river de- scribed, 87-88.

Tertiary, condition of shells in, 88. definition of term, 16. deposit, Mr. Lyell on, 16. at Fortress Mon- roe, 725.

Tertiary of Europe, 16, 16

a deposit of sand and clay transported subsequent to forma- tion of, 257.

Tertiary, description of Miocene dis- trict of, 427.

Tertiary, diatoms of western outcrop of, 726.

Tertiary, diluTial action on, 665. "" discovery of the extension of, at mouth of James river, 725.

Tertiary, disposition of the fossils in, 86-86.

Tertiary, explanation of column rep- resenting strata in, 264.

Tertiary, extent and topographical features of, 419-420.

Tertiary extent of, eastward, 738. Eocene and Miocene shells of, 669-678.

Tertiary, fossils of, 661-673.

Tertiary of Virginia, no traces of fresh-water fossils in, 16.

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Tertiary, geology and topography of,

Tertiary, infusorial stratum in, 449-

Tertiary, in vicinity of Smithfield,

Tertiary, irregularity in western

boundary of, 261. Tertiary, Ihnits of, in tract south of

the James river, 269, 268. Tertiary, limits of Miooene and Eo- cene districts of Peninsula, 421-

Tertiary, lower, in Alabama, 12, " lower, strata of described,

Tertiary marl, see Marl. Tcrtiaiy marl region, defined, 26, 28. railroads from

Carolina to New York following

boundary of, 254. Tertiary, near Petersburg, 448. " Richmond, 442. Middle, 12. Miocene, 28,82,419. no older formation than, on

James river, below Farra's island,

Tertiary, on the Meherrin, Nottoway,

and Blackwater rivers, 276, 277. Tertiary, probability of the extent

eastward of, beneath the plain of

Norfolk and Princess Aime cos.,

267-25a Tertiary shells, Mr. Conrad on, 664. " south of James river, 251. subdivisions of, 16. *'The Cause and Phenomena of

Earthquakes,'* Michell on, 682. Theory of the flexure and elevation

of the strata of Appalachian chain,

Thermal springs, see Springs.

springs in connection with

the theory of volcanic agency, 677. Thermal springs referred to a perva- sive subterranean heat, 596. Thermal springs, temperature of, not

dependent on superficial causes,

Thermometer, use of, in measuring

heights, 193. The tunnel, 91, 719.

8oe

"The Virginia8, 788.

TiUnium, 88.

Topographical map, by Mr. Jed.

HotchkiBs, 121. Topographiod map, flee Map. Topography of Appalachian chain,

Topography of northern portion of

Tertiary of Virginia, 419. Transactions of Geological Society of

London, 632. Trap, 88, 216, 808, 828, 829, 460.

" associated with coke, 677, 678. Trap, greenstone, 476, 477.

modifying influence of, 476. Tniprock associated with Middle seo-

ondary, 476, 480. Travertine, as a substitate for lime- stone in agriculture, 95, 104. Trarcrtine, formation of, by streams,

96, 104. Trayertinc in For. II, 172.

neighborhood of the

Sweet springs, 104. Travertine marl, see Marl.

near Corington Hot springs, 104. Travertine, rocky, 173. Tremolite, 469. Trenton Division, 717. Trias, 767, 768.

of Europe, 766. Trioeratium, 734.

acuturo, 736. amblyoceros, 786. Marylandicum, 736. Trilobites, 94. Trough near Jemiings's gap. Little

North mt., 181. Tufaccous deposit from springs at

Snake Run mt., 688. Tufa of Falling Spring creek, 726. Turritelhi, 87, 887, 388, 784. alticosta, 87, 484. fluxionalis, 669. Mortoni, 486. plebeia, 484. quadri-striata, 661. ter-striata, 484, 661. variabilis, 661, 662, 669.

U

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Umbral limestone, 717. scries, 688.

Umbral shales, 717.

Unconformity of certain strata in Axoic rocks, 769.

Upper and Lower Mesozoic, 717. Barren Group, 717. Cambrian, 717. " Carboniferous, 717, ooal group, 498-604, 717.

Upper coal group, nse of term, 486. secondary, 717. " ancient diluvium

of, 447.

Upper secondary, character and con- tents of, 442-449.

Upper secondary, diiiiculty of dis- tinguishing, from the surface drift,

Upper secondary of the plain, south- east of the Appomattox, 448.

Upper secondary on James and Rap- pahannock, 447.

Upper secondary sandstone of Vir- ginia, belonging to Oolitic period,

Upper secondary standstone of Vir- ginia, dipping beneath the Eocene Tertiary, 712.

Upper secondary strata, variations of dip of, 446.

Upper secondary strata, vegetable impressions in, 444, 446.

Upper secondary, thickness of, 442,

Upper shale and sandstone group, use of term, 486.

Upper subcarbonifcrous shales at Hinton, 726,

Utica Division, 717.

Vegetable impressions in clay asso- ciated with infusorial earth, 452.

Vegetable impressions in shales of coal measures, 876, 878.

Vegetable remidns in eastern ooal field, resemblance of, to those of Oolite coal of Europe, 646.

Vegetable remains in section near Wheeling creek, 613.

Vegetable remains in shales of Pride- vale district, 690.

Vegetable stems, 477. Veins of injection, 76. Veneiicardia alticosta, 88.

ascia, 887, 671. planioosta, 671. granulata, 434. Venus, 887, 784.

cortinaria, 484, 668. deformis, 86, 87, 484. mercenaria, 42, 484. Vergent, 717.

Vespertine of Narrowback mt, 722. series, 688. sandstone and coal, 717.

Woter, action of, in formation of peb- bles, 816.

Water, action of, on shells in marl, 271, 274.

Water, denuding action of, 881. " nature of, in Miocene marl re- gion, 40.

Water, temperature of, in coal mines,

Waters of Pyrmont, M. Hoffman on,

Weald, sections in, 641. Wealdcn of Europe, 718. Wcaldcn period, 712, 718. Whetstone, 77, 78.

or indurated fire-clay for

manufacture of bricks, 705. Whinstone in ooal measures near

Richmond, Va., 677. White sandstone, 616.

Zamites, 646, 667.

blechnoides, 667.

heterophyllus, 649.

obtusifolius, named, 656, 658. Zamites, tenuistriatus, 657. Whitbiensis, 667. Zanthiopyxis oblonga!, 786. Zoophytes, 102, 268.

Index.

Pabi II.

Names Of Persons And Places.

it

AaroQ*s creek, 489, 490, 492. Abb's valley, 195, 623. Abbyrille, 482.

Abingdon, 294, 395, 616, 726, 728. Abraham's creek, 849, 861, 354, 356,

Acasto, M., 632. Accakeek creek, 423, 425, 440. Aocomack co., 417. Acquia creek ; sandstone, 29, 70, 4 23,

436, 440, 443, 712. Adie, Mr., 443. Aestbam river, 466, 474. Aikin, Prof. W. E. A., 166, 191, 192,

247, 763. Aix, in Provence, 677. Alabama, 196, 817, 602.

geological division,606,6 1 2. eocene, 19. lower tertiary, 14. Albemarle oo., 77, 86, 91, 182, 247,

286, 290, 300, 821, 418, 418. Albion, 422, 436. Alderson, 720. Aldie, 464, 469, 477, 478.

turnpike, 476. Alexandria, 121, 454, 474, 709, 721,

728, 729. Alexandria and Fredericksburg cross- ing, 721. Alleghany, 719. Alleghany ; Backbone axis, 840, 360,

Alleghany co., 161, 178, 179, 181. erroneous application of

term, 110, 111, 113. Alleghany; Front ridge, 183, 196,

260, 830, 336, 839 847, 349. Alleghany and North mt. region;

springs, 101, 104, 106, 107.

Alleghany; coal, 408.

mt., 26, 27, 688, 614. " Hampshire oo., 117. " Penn., 348, 622. " range, 106. " ." rocks of, 97-111. Allen, Mr., 260. Alps, The, 639. Alum Spring (Rockbridge AltimX

101, 668. Ambler's, Col., 462. Ambler's hill, Richmond, 738. Amelia co., 286.

" C. H., 481, 726. Amherst, 721.

" ca, 86, 87, 91, 92, 281, 290, 296, 311. Amherst G. H., 481 Anderson's, Mr., 827. mine, 68. pit, 634. Andrew's, Mr. ; limestone, S06. Angel's rest, 109.

Anna furnace, 681, 689, 694, 701,

Anthony's creek, 688. Appalachian axes, 626, 627, 629. belt, 709.

ron west of valley, Applebury's mt, 296. Appomattox, 727.

" mt., wrongly so called,

Appomattox, falls of, 71.

" river, 63, 261, 261, 328,

826, 437, 442, 448, 466, 482. Arago, M., 694.

u

80d

Archer, Mr., 260. Archer's creek, 804, 805, 891. Archershope, 160. Archer's quarries, 307, 891. Amey's town, 7, 8. Arrington, 721. Arthur's quarry, 390. Ashbj's gap, 456, 462.

'" section, 454, 628. Ashbj ore, 692. AshUnd, 724.

Askema mineral springs (noteX 689. Atkinses, Mr.; marl, 168. Atlee, 719. Augusta CO., 27, 98, 174, 207, 529,

Augusta springs, 101, 224, 228 Austin, Mr., 689. Austin's run, 428, 425. Austinvillc lead mines, 726.

Bachelor's Hall, 321. Back creek, 208, 890, 613.

" mt., 161, 179, 247. Bacon's Castle ; marl, 48. Bagby'e, Mr., 168. Baker's, Mr., 469, 704. Baker's gold mine, 728. Balbronn, Europe ; fossils, 649. Balcony falls, 89, 98, 167, 204, 206,

Bald Eagle axis, 614. Baldwin's ridge, 464, 474, 476. Ballinger's creek, 801. Balsam mt, 416. Baltimore, Md., 140, 709, 712. Baltimore and Ohio railroad, 474. Bannister river, 821, 826, 725. Baptist ralley, 196. BarbourSTille, 818, 464, 478, 720. Barksdale, 726. Bam rock, 177. Bamett's ford, Bapid Anne river

461, 473. Barney's, Mr., 702. Banmm's, Mr., (quarries), 296, 314. Barr's pits, 634, 635. Baruth, 654. Bas Boulounais, 641. Basset's, Washington, 62, 54. Bath, 226. Bath Alum Springs (Brinkley's), 569,

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Bath CO., 161, 171, 177, 178, 179,

181, 613. Bath Springs (Berkeley), 581, 590. Battersea, 467. Baylor's run, 478. Beach creek, 446. Beale, Messrs., 609. Bealeton, 721. Bear creek, 861.

creek fumaoo, 867. island, 70. Knob, 208. Beard, Mr., 448. Beatie's drift, 702. Beatty's, Mr. ; coal, 366, 409. Beaver creek, 66, 88, 287, 297, 304,

806, 890. Bearer dam, 72, 441, 719.

" Meadow basm, Penn., 618. Bedford co., 81, 287, 290, 294. Beech island, 474. Bee run, 368.

Belgium ; Geological Structure, 639. Bell creek coal, 881, 406. BeUefield, 4, SO, 38, 724. Bellefield; section, 481, 482. Belle farm ; marl, 48. Bellefonte, 614. Belmont, 480. Bent mt, 196, 482. Bennett's creek, 268, 278. Berkeley, 55, 60, 260.

anthracite coal, 100. CO, 27, 99.

Springs, Bath oo., 581. Berkshire marble, 606. Berkshire valley, Mass., 606. Berks co., Penn., 622. Bermuda Hundred, 260. Bernard's, Mr., 163.

" Wm.; marl, 161.

Berthier, M., 8. Berthesay's coal bank, 517. Berwyn mts., 688. Beverage's, Mr., 162. BeviPs bridge, 482. Bideford, 689. Big Buffaloe creek, 862, 625 " Coal hill, 697. " Coal river, 626. " Fort vaUey, 159, 174, 220, 221, Biggs's mt, 589.

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Big hill coal, 708. Kanawha, 506. '' Lick, 892. " Monocacy, 4*74. " North mt, 204. Sandy ridge, 688. Sandy river, 868, 409, 486, 498,

504, 506, 526, 584. " Sandy, valley of, 486. Sewall mt, 115,840, 842,878, 405, 406. Big Spring, 727.

Big and Little Timber ridges, 182. Tuckahoe creek, 488. " Tunnel, 727. " Yellow creek, 508. Billups's, Mr.; marl, 152, 158. Birdsong, Henry ; marl, 889. Biechoff, Prof., 577, 578, 579, 504. Bizarre Estate, 828, 327. Black creek, 887. Black Heath mines, 63, 65, 482. Bhick Heth Co., 671.

" new shaft, 671, 678. Blackford, Br., 221. Blackford's furnace, 898.

iron mines, 220, 240.

ore bank. Page co., 240.

Black Log anticlinal Talley, Penn.,

Black rircr limestone, New York,

Black rockf), 168. Blacks and Whites, 727. Blacksburg, 170. Blacksmith coal vein, 701. Blackwater creek, 849, 350. " river, 887, 888. Blaettermann's, Dr., 801. Blaky's Col.; marl, 152. Bloomery, The, 396. Blowing Cave, Bath oo., 90, 728. Blow, Col., 277, 888. Blue Ridge, 26, 72, 77, 88, 111, 184, 156, 167, 171, 192, 195, 204, 290, 295, 413, 440, 447, 481, 610, 628, 630, 709, 726, 727, 769. Blue Ridge, rocks of, described, 89-

Blue Ridge; valley slope, 197. sections, 92, 454. Springs (Buford's Gap Springs), 684.

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Blue Stone mt, 837, 840, 878. Blue Sulphur Springs, 106, 558. Blunt, Mrs. ; marl, 889. Boasman, Mr., 877. Bohemia, Polir Scheifer or Tripoli of,

Boiling's bridge, 261, 268, 267. Bolt hill, 689. Bonsacks, 727. Bonn, 577.

Bond springs, 588, 690, 691. Booker's mine, 76. Booth's creek, 490, 491, 6C6. Booth's, Mr., 154, 685.

" mill, 887.

" Mr. George, 482. Booth, Prof, 712. '

Bore Auger mt., 267. Borodmo, 422. Boston, 726.

" Society of Nat. Hist., 677. Botetourt co., 98, 186, 208, 218.

" springs, 101, 222. Borden, Mr. ; marl, 888. Bowers, Dr. ; marl, 887, 888. Bowman's hollow, 381, 882. Boxley's gold mine, 723. Boyd, Dr. George W., 192, 247, 418,

416, 539, 768. Boyd's Hole, 436. Boydton, 482. Boyer's mill, 496.

" mine, 498. Boykin's, 728. Bracken's Ridge, 116. BranamB, Col. Phil ; marl, 151. Branch mt., 181, 182. Brandonville, 409.

road, 863, 868.

Brandy, 721. Branzburg, 862, 363, 854, 866, 405,

Bratton's Ridge, 99. Braxton's, A. ; marl, 162.

" Dr. Charles, 61, 62. " Dr. Corbin; marl, 19, 60. Bream's, Sir., 881.

" coal bank, 407. Bremo, 72, 78, 79. Brcntville, 474. Bridge hollow, 882. Briery axis, 869, 862, 879. branch, 228.

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Briery mt, 360, 861, 863. Brigg8, Mr. C, 418, 640, 768.

Capt. : marl, 888. Brine Springs, 142. Brinkley'8 Sour Spring (Bath Alum),

Bristoc, 721. Bristol, 728.

" hot wellfl, Eng., 677. Broad run, 464, 473, 723.

Top coal field, 622. Broadwater bridge ; marl, 388. Broadway, 261, 442, 448, 718. Brock's gap, 224, 228. Brogniart. M., 16, 647, 649, 660,

661, 667. Brook creek, 172. Brooke oo., 383, 486, 606. Brooke, Mr., 443. Brooke*8, 724.

" run, 468, 4V3, 474. Brook's, 292, 297.

" drift, 381.

" mill, 423, 426, 410. Brookneal, 288, 311. Brora coal field, 648, 646, 649. Browne, Peter A., 749. Brown, Mr., 647. Brown's gap, 89, 204.

" mt., 99, 177, 684, 688. Brown's ridge, 98. Brownstown, 720. Brunswick, 70.

" C. n., 481. Brush mt., 165. Brushy mt, 111, 201, 204, 219, 220,

611, 617, 726. Bitishy ridge, 102, 109, 336, 616,

Bryant Mr. ; marl, 889. Buchanan, 206, 208, 212, 216, 219,

Buchanan's banks, 141. Buck creek, 441. Buck-horn ridge, 614. Buck Island creek, 301, 304, 892,

Buckingham co., 27, 88, 126, 281,

286, 287, 290, 291, 213, 311, 320,

822, 459. Buckingham ; gold belt, 314. C. H., 24. iron works, 78.

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Buckingham road, 483.

Buckland, Dr., 677, 639.

Buck, Mr., 221.

Buckton, 723.

Buddies, The, 140.

Buffalo creek, 216, 268, 307, 823,

366, 720. Buffalo Lick run, 409.

" Ridge, 87, 88, 803.

Ridge spring, 87.

river, 820, 822. Bufoid's, 727.

gap, 206, 684.

" section, 482.

springs (Blue Ridge springs), 684. BuUenreit; Europe, 664. BuU HiU, 442, 448.

(( creek 449. Bull Pasture mt., 161, 162, 178, 181,

Bull Run mt., 133, 134, 469, 460,

461, 464, 476, 723. Bulltown, 606. Bumpass, 719. Burford's, 721. Burke's, 721.

" run, 888. Burk's garden, 684.

" swamp, 277. Burkeville, 725, 727. Burlington, 384.

Burning spring, 874, 378, 606, 626. Burton's, Mr., 158. Burwell's bay, 46, 276. Burwell, Mr. ; marl, 46. Burwell's Mill, 4. Busby's Spring. 684. Butchertown ; infusoria, 462. Butler ore, 693.

Cabell CO., 344.

Cabell's, Mr. J. ; marl, 47, 151.

quarry, 806. Cupon axis, 590.

mt., see Capon mt.

" river, 169. Caermarthenshire, Wales, 688. Ca Ira, 812, 316, 820, 328. Calabrian earthquake, 632. Caldweirs mt., 204, 219, 220, 228. Caledonia, N. Y., 96. Calf Pasture river, 103.

Gallahan'8, 106, 157, 181.

Gallie iron mine, 723.

Calloway's Rocks, 168.

Cameron, 718.

Gamp mt, 218, 221, 222.

Campbell oo., 81, 88, 281, 286, 288,

290, 291, 293, 811, 820, 890. Campbell C. H., 804, 482. creek, 116, 879, 380. creek coal, 406. Campbell, David, President Board of

Public Works, 148, 190, 246. Canada, 608, ri06. Capitol, The, 710. Capon or Cacapon Springs, 688, 690,

Capon mt., 161, 178, 181, 681, 590.

" Road, 718. Caradoc sandstone, 688. Carey's bridge, 277. Carlin's, 729. Carolina border, 426. marl, 6.

" N., 260, 254, 297, 307, 817, 819, 321, 888. Carolina, states of, 816. Carr, Mr., 685, 689, 700, 701. Can's run coal seam, Ohio 498. CarrsTille, 728. Carter's Bridge, 301. Carter oo., Tenn., 209. Carter's creek, 426. Carter's, H. St. L., 486. " miU, 476. mt., 84, 461, 466. Cartrell's, Mr., 627. Carrin's cove, 222. Canrer's, Reuben, 87. Cascade Tillage, 821, 824. Castle Hill, 216. Catawba coal, 100, 136.

creek, 228, 394, 617. furnace, 222, 229. iron works, 220. mt., 97, 99, 118, 166, 169, 219,223,611,725. Catlett's, 721. Catoctin, 134. Catskill mts., 608, 609. Cedar creek, 94, 181, 686, 718. valley, 683, 691. " works, 630. grore, 893.

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Gcdar ran, 474.

Central, 727.

Centre oo., Penn., 618.

Centreville, 474.

Chalk Level, 822, 826. .

Chancellor's, 182.

ChanUUy cliffs, 420, 429.

creek, 428. Chapman's ferry, 218, 217. Charles City, 166. Charles City co., 166. Charleston, 116, 118, 342, 844, 873,

879, 882, 888, 486, 606, 720. Charlestown, 170, 172, 216, 718. Charlotte C. IL, 289, 822, 326, 480. section, 481, 482. CO., 281. line, 311. CharlottesTiUe, 24, 88, 296, 300, 466,

719, 721. Chatham, 722.

Cheat mt., 117, 201, 339, 840. river, 386, 360, 368, 866, 868, 370, 409, 488, 491, 606, 682. Chericoke, 52. Cheny Point, 481. Cherrystone creek, 322. Chesapeake bay, 26, 89, 121, 738. Chesapeake and Ohio Canal, 216. Cheshire, Eng., 112, 118. Chester, 724.

gap ; section, 464. Chesterfield, 27, 63, 66, 69, 414, 718. C. H., 483. CO., 63, 69, 70, 126, 181,

166, 261. Chesterfield ; coal, 480.

coal basin, 446, 633, 684. depot, 442. tunipike, 482. Chestnut ridge, 628, 684, 622. " axis, 621.

" Penn., 868, 888. Chestnut's store, 821. Chevallie, J. A., Esq., 566. Chickahominy river, 80, 446, 484,

Chili ; earthquakes, 686. Childer's, Mr., 377. Chilton's plantation, 806. Chimney rocks, 216, 223. Chingotcague creek, 128, 421. Chinquapin ran, 888.

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Chipoak'B, 160.

'' creek, 269, 886. Ghissel, Col., 88. Ghopawamsic creek, 441. Chowan river; section, 121. Christian, Dr. R. ; marl, 47.

Mr. Robert, 47. Christianas creek, 174, 808. Christiansburg, 111, 170, 727. Chuckatack, 269, 276.

mill, 166, 266.

Church hill, Richmond; infusoria,

Church Road, 727. CSndnnati, 617. Citj Point, 29, 66, 260, 448, 449,

CUrksbui 117, 248, 884, 401. '' cool, 410, 486, 498.

limestone, 499.

Claricsbnrg or Horgantown seam, 641. Clark's gap, 729. CUrksYiUe, 482. Clear's furnace, 671. Clellan ore, 692. Clement's ford, 807. demson, Mr., 647. Clennont, 166, 886. Cliff rock. Cheat, 687. Clifton, 721.

" forge, 688, 687 724. Clinch mt, 620, 726.

" aiis, 620.

river, 602, 606. Clinton furnace, 696.

group, 618. Cloverdale furnace, 208, 222. Clover forest road, 828. Cloverland, 188. Coal creek, Kanawha, 626. Coalbrook dale, 684. Coalburg, 720. Coal river, 117,624.

" run, 100, 614. Cobb's, 448.

creek, 442. Cobham, 719, 721. Cockle-shell branch, 482. Cock's, Mrs. ; marl, 166. Coggin's Point, 17, 28, 66, 166, 166,

260, 889, 666, 668. Col. Ambler's hill, Richmond; in- ' fusoria, 461.

Colchester, 441. Cole's, John, 690, 694.

" Point, 429.

(Sam) mine, 690. Coles, Tucker, Esq., 86, 296, 297. Golesville, 488. College creek, 166, 886.

mill ; marl, 84, 86. CoUierstown, 221. Collin's ferrj, 288.

" ore, 698, 700.

ore banks, 708. Columbia, 24, 71, 72, 77, 268, 289,

464, 466. Columbian College, 710, 712. Combe-MarUn, 689. CompeUtion; section, 822, 482. Concord, 727.

meeting house, 441. Connecticut valley, 817, 686. Conrad, Mr., 12, 14, 664, 666, 668,669. Conjbeare, Rev. Mr., 677, 760. Cook's mill, 826. Coomb's property, .699. Cooper's mt., 228. Corbell's, Col.; mari, 166, 886. Cornwall, Wales, 688. Cotopaxi works, 208. Cotton Hill, 874, 720. Courthouse creek bridge, 168. Covan, Mr. Johnson, 864. Cove mt. ; section, 624. Covesville, 721. Covington, 97, 102, 104, 219, 614,

719, 724, 726. Covington ; section, 24. Cowherd's, Colby; limestone, 620. Cowpasture hills, 99, 181.

river, 179, 728. Cowper's, Mr. ; marl, 164, 886. Cox's (Mr, mine, 684. Cox and Hannah's coal, 407. Crab-bottom, 174.

" valley, 171, 174, 176,

Crab creek, 619.

'' creek, Md., 848.

Orchard road, 868, 867, 868. Crabtree " 849.

Craigsville, 719. Crane, Mr., 866. Crawford's mt, 217, 2i 226, 228,

Creek pit, 588, 570. Gresap'fl, Mr. ; coal, 410. Crimson Balphur spring, 624. Cripple creek, 139, 726. CrockerB, Major; marl, 155, 886. Crooked creek, Point Pleasant, 525.

run, 474. CroeswickB creek, 7. Crouch*s lower shaft, 585.

mine, 63. Crowe's, 105. Cramp, Mr. B. ; marl, 47. Culpeper, 721.

CO., 125, 132, 188, 817, 825, Culpeper C. H., 454, 478, 474, 478. Cumberland, 121, 612.

Co., 69, 73, 281, 284,

289, 820, 828. Cumberland C. H., 812, 815, 326.

section, 480, 481.

gap, 531.

" Md., 847.

mt., 195, 608, 629.

Talley, Penn., 608, 622. Cunningham, Mr , 857. Curratoman, 47.

" river. 426, 480.

Cutch, geology of, 647, 656. Curicr, M., 15. Cyclopean towers, 216. Cypress creek, 276.

Dagger's Spring (Dibbrell's), 661. Dallas river, 821. Dan mt., 836, 848, 849.

river, 821, 822, 324, 725.

river, N. C, 718. Danville, 289, 822, 722, 725. Darst's, 207. Darwin, 632, 634. Daubeny, Dr., 577, 578, 689, 594. Davy, 554. Davy's mt., 115. Day's, Mr. H. ; marl, 158, 886. Day's Point, 164, 268, 269, 272, 276,

Dean, Mr., 80. Decker's creek, 486, 488, 490, 493,

603, 506, 671, 696. Deem's coal, 406. Deep Bottom; marl, 156.

James river, 449.

it

M

Deep Hole, 262, 442.

Hollow creek, 409.

" " run, 866, 367.

river; coal rocks, 718.

run ; coal basin, 446, 535.

" Run church, 484.

" " pits, 65.

'' Shaft mine, 68. De la Bache, H., 637, 688. Delaplane, 728.

Delaware and Chesapeake canal, 6. Delaware; geological division, 604,

Delaware river, 8, 631, 711. Deposit mine, 75. Devil's Backbone, 176. Devonshire, 638. Dibbrell's spring (Dagger's), 225,

890, 896, 661. Dickson's sulphur spring, 561. DtfficuU creek, 349, 351, 859, 463. Dippe; springs, 579. Dillenburg, 640. Dinwiddle C. H. ; section, 481. Dispatch, 726. Disputanta, 727. Dittoway branch of Jones's creek,

Dogwood ridge, 116. Dolomieu, M., 632. Donally (Beypolds and Donolly), 880,

Dora coal mines, 722. Douglas's ; marl, 155, 886. Dover church, 483.

mill, on Little river, 469. Downing's, Mr. S. ; marl, 161. Dranesville, 468, 478, 476. Draper's mt, 166, 196, 219, 228, 727.

" vaUey, 228, 684. Drew, Benj., 388. Drewry's Bluff, 724. Dry creek, 823, 482. " Fork, 722. '' Cheat river, 826, 335, 349,

Dry river gap, 182. run basin, 481. Run gap, 769. Seneca creek, Md., 474. Dromagh coalfield, Ireland 639. Dublin. 727. DucaU Prof., 19.

Dumfries ; eection, 441, 454. DumoDt, M., 687, 63U. Dumpling island, 164, 586. Duncan, Judge, 401. Dunkard's creek, 603. Dunlap's ci*eek, Monroe oo., 621. Duprez*8 bridge, 277. DuTaPs, Mr. ; marl, 163. Duval creek, ore beds, 690, 694. Djer'B mill, 801, 891.

Eaglets nest, 436.

Eastern or Potomac basin, 849,

East Rirer mt., 588, 698, 629, 725. Eastern Virginia, 6, 8, 49, 96, 649. Ebbing spring, 585, 723. Eclipse lock, PrideYale, 698, 703. Edinburg, 718. Edmundson, 216. Edmondson's spring, Augusta co.,

Edmonson's big spring, 684. Edwards's, Mr. ; marl, 168. Edwinton, Mr., 443. Ehrenburg, Prof., 489, 735. Eif el limestone, 640. Eight mile island, 618. Eighteen mile creek, 518, 625, 582. Elie de Beaumont, M., 622. Elk creek, 890, 892, 528.

creek Iron M. Co., 808.

Garden, 864, 355.

Island creek, 802, 805, 811.

" river, 346, 879, 627.

" run, 474. Elkton, 474, 478. EUet's, Mr. ; mari, 168. Elmington, 721. Ely, Mrs., 387. Elizabeth City oo., 156, 272. Elizabeth river, 261. Emmet, Prof., 89. Emmons, Prof., 606. English (Warth and English), 407. Eppes's falls, 482. Essex CO., 81, 163. Etna furnace, 222. Evansville, 368. Evergreen, 55, 155, 260, 889, 666,

Everlie's mill, 861, 897. Evington, 721.

Faber's, 721. Fairfax, 454, 479, 721. Fairfax oo., 459, 463. Fairfax, Col., 865, 400, 408. Fairfax's stone, 348. Fair Oaks, 726. Fall creek, 722.

Hill mt., 295, 296. Falling creek; section, 822, 441,

481, 482. FalUng spring, 104, 681, 585. " " creek, 725. " " valley, 248, 614. " river, 628, 812. Fall's church, 729. Falmouth, 69, 441. FarmviUe, 816, 318, 320, 322, 725,

Farmwell, 729. Farra's island, 442, 448. Faulcon's, Mrs. ; marl, 156, 386. Fauntleroy, T. W. ; marls, 46. Fauquier co., 125, 134, 287, 317,

825, 459, 468. Faure's coal bank, 382, 407.

salt furnace, 882. Fayette oo., 184, 196, 248, 406. Field's creek, 369. Fmcastle, 206, 216, 228, 395. Findlay's mt., 295, 818. Finney, Capt., 534. Fish Hall, 726. Fishmg creek, 121, 892, 506.

" " Ohio river, 568. Fishersville, 719. Fitton, Dr., 637, 640, 641. Fitzgerald, 821. fltzhugh, Mr., 443. Flanigan's settlement, 86 L Flat creek, 806, 807, 891. " swamp, 269, 277.

" Top mt., 196, 248, 541, 584. Floumoy's, 818, 827.

coal pit, 822. Flowing spring, 172. Floyd CO., 168, 171, 173, 196, 209,

Floyd, Governor John, 749. Fluvanna oo., 74, 78, 80, 125, 821,

Folly, The, 86, 88, 281. Folly mine, 297. Forbes, Prof., 577, 579.

Ford'B, 121.

Forest, 727.

Foiee, The, 108.

Fork meeting-house, 478.

ForiL mt., 614.

Foniian*8 plantation, 397.

Robert ; coal, 409. Forrer's bank. Page co., 529. Fort Defiance, 718.

'' Lewis mt, 196, 219, 222, 628,

Fortress Monroe, 725, 783, 735. Fort mt. synclinal, 723.

Spring, 720.

Washington, 14. Foot Mile tree ; marl, 155, 886. Fox Creek gap, 769. Fox's, Mr., 52, 54, 574. France, 136. Fianklin, 297, 887, 388, 728.

" CO., 26, 88, 290, 807, 312. Freeman*8 ford, 474.

(Mr.) bmding, 509. Freestone Point, 440. Frederick co., 27, 95, 99, 104, 174. Fredericksburg, 7, 17, 69. 80, 126, 181, 428, 440, 454, 712, 718,

Frederick Hall, 719. Frederickton, Penn., 508. French Garden, Ridunond ; infusoria,

461, 462. Friend, Welsh and Co.'s mines, 527. Friend, Mr., 381. Front ridge of Alleghany, 628. Front Royal, 723. Frostsbarg, Penn., 348. Fry, Mr., 378. Fulk's, John; marl, 152. Fonks, Mr. ; marble, 12, 13.

Gahiesville, 723. €klbraith's, springs near, 584. Gallahom, Mr., 443. Gallipolis, 334, 618. Gait, Dickie ; marl, 47. Gap, The, 166.

" spring, 581, 686. Garden mt., 219, 589. Gardner, Dr., on mineral springs,

GarUind, Mr., 301.

Garrett's, Mr. R. ; marl, 48.

Gary's, 728.

Gauiey mt, 115.

Ganley river, 117,877.

Gee, Col. ; marl, 389.

Germanna ford, 182, 454, 474.

Gemonrel ; forails, 649.

Genesee ; geological diTisioii, 7l7.

Genito road, 482, 488.

George creek, 822, 825, 879, 880.

Geos, Mr. Warner, 151.

Georgetown, 464, 474, 479, Y09.

Geofgia, 816w

Geraidstown, 226.

German settlement ; iron, 860.

Germantown, 478.

Gibson's vein; limestone, 519.

Giles CO., 162, 165, 184, 196, 218,

894, 728. Gill, Mr., 685. Gilmer, Thomas W., Prest. Board of

PubUc Works, 412. GIsh's, 727. Glade creek, 807.

" spring, 728. Gloucester C. H., 158.

" ca, 43, 46, 152. Goblintown creek, 807, 312. Goldsby's fall, 829. Goochland co., 27, 61, 71, 126, 180,

247, 261, 414, 478. Goochland C. H., 66.

'' coal, 480, 684. Good, Mr. John Mason, 758. Goodall's, 441. Goode's bridge, 488. Goodwin's, W. H. ; mari, 156, 886. Goose creek, 297, 807, 469, 478,

Gooseman's bridge, 487. GordonsYille, 85, 800, 466, 620, 719,

Goshen, 719.

" Pass, 728. Goremor's Hill, Richmond, 60. Governor St., Richmond; infusoria,

Graham's, Mr., 216, 217.

bank, Wythe co., 629. land, 139. station, 618. Grand creek, Kanawha, 626. Grant, Capt C. W., 647, 656.

Granville, 498.

Grassy Hill, 297.

Grave creek, 617.

Grayson co., 110, 121, 126, 189, 196,

Gray's mill, 428. 440. Greaners, Mr., Richmond ; infusoria,

Great Bridge, 257.

" Flat Top mt., 113, 887, 878.

" Kanawha coal, 117, 484.

" Kanawha river, 117, 121, 248,

880, 844, 873, 414, 486, 498. Great Kanawha; salt wells, 118.

and Little Kanawha valley,! 18.

" Levels, 889.

" North mt., 97, 176, 226, 590.

Shenandoah mt., 169, 181.

WilUs river, 828. Greenbrier co., 161, 181, 184, 196,

201, 248, 836, 341. Greenbrier mt., 27, 118, 196, 248,

Greenbrier river, 108, 118, 181, 184,

836, 872. Green bottom, 619. Greenhole pit, 670, 678.

shaft, 633. Green mt, 86, 286, 293, 296, 466.

" mts., Vermont, 602.

Spring, Louisa, 469. gap, 226, 226. lands, 286. Greensville co., 70, 248, 389.

June, 724.

Greenville furnace, 370. Greenway, 288, 294, 803, 806, 890. Greenwood, 719. Gregory's gap, 769. Grenville works, 401, 402. Gresham's, Mr. ; marl, 153. Grey Sulphur Springs, 106, 109, 894,

Gribblo, Mr., 869. Griffin, Major T. ; marl, 48. Griffith, Mr., 639. Ground Squirrel bridge. So. Anna

river, 446. Guilford, 729. Guinea, 724.

Gum Camp run, 868, 397. Gum Spring iron ore, 686. Guyandotte, 344, 606, 618, 619, 720.

it

Guyandotte; section, 24, 121.

" river, 121,196,416,610,

Haco's land, 699.

Hagan's, Mr. ; coal, 867, 899, 409.

Haines and Snake-den group of ores,

698, 700. Haines ore, 698, 694. Hailey's, Gapt. ; marl, 162. Haibume, G. B., 649. Halfway, 724. Halifax co., 281, 288, 820.

" C. H., 289, 480, 482. Halltown, 718. Hamilton, 729.

Hamilton, Mr., on structure in Ire- land, 689. Hamilton Place, Nicholas co., 632. Hamilton; geological division, 717. Hamilton's knob, 223. Hampden Sidney College, 822. Hampshire co., 117, 163, 184, 196,

330, 886, 847. Hampshire coal basin, 407.

" furnace, 396. Hampstead, 62. Hampton ; marl, 166.

Roads ; section, 24.

Hancock, Col., 811, 628. Hancock's quarry, 392. Handsford, Mr. Morris, 877, 378. Hanging Rocks, 179. Hanna coal, see Hannah. Hannah's, Cox and, 407. Hanover co., 50, 61, 61.

road, Richmond ; infusoria, 462.

" C. H., 719.

" section, 464. Hansford's ooal seam, 406. Happy creek, 723. Hardware river, 79, 296. Hardy coal basin, 866, 407. Hardy oo., 126, 161, 177, 181, 198,

248, 330, 386, 347, 350. Hare, Dr., 689. Harlan, Dr. R., 763. Harper's Ferry, 92, 170, 204, 464,

621,522,718, 769. Harrison co., 248, 344. Harrison, Mr. Wm. ; marl, 47. Harrison's, Mr., 827.

mill; marl, 389.

Harrisonbni, 718, 722.

section, 24.

Harrises Branch, 288, 308. Harrogate mineral springs, 669. Harry's swamp, 262. Hartman, Mich'L, 867. Hartman's iron ore, 404. Hartz mts., 640. Harvey's, Mr., 868, 381. Hastie's, Mr., 698, 699. Hat creek, 812. Hawk's Nest, 720. Haycock's Spring, 688. Hayden, Dr., 807.

Mr. Chas. B., 118, 149, 166,

191, 413, 768. Haymarket, 728. Hazel run, 441. Healing Springs (Sweet AlomX 681,

Hedgeman's river, 474. Hedgesville, 226. Hedley'a, Mr., 162. Heder Springs; Germany, 679. Helderberg strata, 636. Hendricks, Mrs., 823, 327. Henkle, Dr., 212. Henry Clay furnace, 371, 488, 681,

686, 687, 704. Henry co., 291, 807, 820.

C. H., 297. Henrico, 718.

Co., 60, 61, 126, 180, 166,

261, 414. Henrico co., coal basin, 446, 480,

634, 636. Hering, Mr., 887. Hemdon, 729.

" creek, SCO. Herring creek, 166, 260. Hervey, Mr., 876, 376, 682. Heth's (Col)., deep shaft, 683. Heth, Potts and Co., 688. Hewitt, Mr., 608. Hickerson's, 474. Hick's ford, 262. Higgins, Mr., 866, 866. Hight Point, 440. Highlands, The, N. Y., 608. High Whitby, £ng., 649. Hill's, Capt., 62.

" Robert, 168. Hinton, 720.

u It u

Hitchcock, Prof., 606, 606, 607.

Hite's mill, 172.

Hocr; Germany, 668.

Hoffman, 677.

Hogsback, The, 641.

HoUeman, Joel ; marl, 46.

Hollow run, 403.

HoUidaysburg, 614.

Holston; geological division, 604,

611, 628. Holston mts., 206.

" ron, 620.

river, 112, 141, 178, 628, 602, 604, 620, 726. Holston river, north fork, 179, 199. south fork, 416. salt region, 112. valley, 140, 142, 177, 178. Hoosic mt., Mass., 606. Hooton's, 862. Hopewell creek, 627. Hopkins, Mr., 687, 640, 641. Homer's, 806.

(Dr.) esUte, 469. Horse rocks, 338. Hotchkiss, Mr. Jed., 121, 769. Hot springs, 104, 566, 586, 724.

valley, 106. House mt, 196, 218, 220. Howard's creek, 108, 115, 188.

Lick, Hardy co., 661. Hoy's run, Md., 361. Huddleston's, Mr., 874, 376. Hudson, N. Y., 686.

river, 603, 606, 610.

river ; geolocal division, 608, 609, 717. Hughes's coal banks, 407.

creek, 874, 876, 377.

river, 117. Hull's creek, 433. Humboldt's observations in Mezioo,

Humphreys, Gen. A. A., 783. Humphrey's spring, 661. Hundsruck mt. chiun, 640. Hunt, Dr. T. S., 769. Hunter's, Mr. ; marl, 153. Hunter's, 729. HuntersvUle, 183, 336, 684w Hunting camp creek, 684. Huntinon, 720. Hunting Quartei 253, 278.

Hurricane, 720.

Hutton, Dr., 647, 651, 654.

Ice's ferry, 606.

lUinois, 317.

Indiana Coal Basins, 317.

Indiana co., Penu., 622.

Ireland, Geology of southern, 639.

Irving's, Mr. H. ; limestone, 306, 891.

Iron mt., 163, 164, 204, 206, 530.

Isabella furnace, 217.

Isle of Wight CO., 46, 163, 218, 386.

Isle of Wight, Eng., 641.

Ivy, Mr., 277, 888.

Ivy, 719.

" creek, 801. Ivey, Mr., see Ivy. Ivor, 727.

Jack's mt, 176, 297, 620.

" Penn., 613, 618, 620.

" " flexure, 621. Jackson co., 844, 510. Jackson, Dr. Charles T., 605. Jackson's mt., axis, 614.

" river, 101, 102, 179, 683,

614, 719, 728. Jacksonville, 601, 602, 503. Jamaica, 632. James City; marl, 11, 43.

" " CO., 82, 40, 46, 156. James river, 4, 12, 17, 48, 204, 262,

269, 276, 288, 297, 820, 384, 414,

434, 442, 456, 467, 481, 534, 616,

711, 726. James river canal, 188, 295, 814,

818, 890, 466. James river ; coke, 677.

" gap, 769.

" " geological division, 604,

James river, lower falls, 150.

" " section, 464. Jarratt's, 724. Jefferson, President, 751. Jefferson, 466.

Jcffries's, R. 0. ; marl, 161. Jenkins's lime kiln, 397. Jennings's creek, 206.

" gap, 181, 225, 227. gap road, 563. Jeremie's Run, 769.

Jerusalem, 887.

Jesse's, Mr. ; marl, 47.

Johnny cake creek, 249, 855, 856.

John's creek mt., 726.

Jones, A. C, 886.

Jones's, A. C. ; marl, 166.

Dr., 151, 430. Jones's mill; marl, 162. Jones, Mr. C. ; marl, 47. Jones's plantation, 38. Jones, Walter ; marl, 46. Jordan's furnace, 102, 243. Jordan's, Mr. S. P. ; marl, 164, 886. Jordan springs, 679. Junction, 724. Juniata ; geological division, 604,610,

Juniata region, 624.

" river, 601. Jura mts. ; strata, 6S(,9.

limestone, 649.

Kanawha co., 118, 143, 844.

" falls, 720.

" river, 116, 342, 877, 883, 406, 618. Kanawha valley, 116, 260, 372. Kayser's, 101, 108, 724.

springs, 683, 686, 592, 694. Kceling's, Mr., 164, 386, 386. Keeny's Knobs, 378. Keezletown, 158, 174, 209, 220. Keller's, see Kelley's.

" creek, see Kelley's. Kelley's, 874, 877, 406.

" creek, 378, 531.

ore bank, 239. Kelso, Mr., 866. KcU's mt., 221. Kenagay's iron furnace, 630. Kent, Eng., 641. Kentucky, 196, 214, 231, 833.

" line, 486. Kemstown, 718. Kerr's run, 605, 610, 617. Keswick, 719, 721. Keysville, 726. Kilmarnock, 433. Kimberling fork, 684. King's creek, 509.

mill, 4, 86, 46, 166, 66&

" river, 820.

'' salt well, 142.

Elng*s tavern, 320. King and Queen co., 153. King George co., 162, 419, 670. King WilUam oo., 60, 163. Kingwood coal basin, 362, 868, 409. ferry, 365. road, 371. Eishicoquillas valley, Penn., 613. Klttoctin creek, 469.

'' mt, 466, 459, 460, 461,

Kltzmiller*ft ; coal, 355, 408. Knobly axis, 613.

mt., 161, 176, 178, 181, 848,

612, 620. Knoxville, 604.

geological division, 606,

Koenig, M., 648. Kurdsville, 323 326.

Lacher See, 679. Lackland tavern, 827. Lahn, The, Germany, 640. Lake Gharaplain, 601, 603, 605. Lancaster co., 47, 151, 419, 430. " Penn., 610. " C. H., 432. Lank enter. Dr., 589. Laurel Hill, 201, 248, 820, 840, 862,

368, 371, 486, 490, 506, 682, 698,

Laurel Hill axis, 370, 414, 621. Lawrence, Mr. ; marl, 387. Lawn's creek, 150. Lawson's (Mr.) opening, 527. Lawyer's Road, 721. Lea, Mr., 668. Leacock, 387.

Leading creek, Ohio river, 408, 617. Leaksville, N. C., 318, 321, 324. Lee, Richard Henry, 429. Lee CO., 166, 196, 216. Lee's mt, 294, 307. Leesburg, 472, 474, 476, 729. Leesville, 294, 297, 807, 390. Lehigh river, 604. Letart's falls, 334. Lewisburg, 105, 108, 116, 136, 186,

Lewisburg valley, 115. Lewis CO., 844. Lewistown valley, Penn., 618.

Lewis, Mr. Charles ; coal, 518.

" Mr. John, 626.

Mr. Samuel, 413, 539. Lexington, 102, 212, 214, 219, 225.

" section, 24. Liberty, 206, 297, 482, 727.

" road, 392. Licking creek. 305.

" run, 478. Lick mt., 196, 219, 223.

Mountain range, 726. Ligon's, 297. Ligontown, Appomattox ; section,

Limestone creek, 467, 476. " place, 801. " spring, 684. Linden, 723.

Lindley, Dr., 647, 651, 664. Lindsay, 824, 719, 721. Lindsay's, Capt., 800. Linton, 689. LinviUe, 718.

Lisbon earthquake, 682, 684. Little Beaver river, Penn. ; section,

604, 506, 507. Little BufFaloe, Kanawha ; limestone,

82& Little Falling river, 288.

" Falls run, 428, 440.

" Fort mt., 896.

Fort valley, 169, 174, 221, 241.

Juniata river, 614.

Kanawha river, 121, 414, 486,

498, 606. Little Kanawha valley, 117, 121.

Levels, 337.

" Lickinghole creek, 66.

Monocacy, 474.

" mt., 687, 688.

" North mt., 27, 97, 100, 201,

216, 219, 224, 228, 584, 690, 611,

616, 623, 723. Little North mt. ; limestone, 624.

" " " ridge, 396.

" river, 442, 445, 469.

" Sandy creek, 362.

" Seneca creek, Marvland, 474.

Sewall mt., 115, 196, 872, 405. Littletown, 4, 86. Little Timber ridge, 182.

Tuckahoe creek, 488.

Little Walker's mt., 16.

Warm Spring mt., 108, 586.

WilliB river, 323. Liverpool, on Ohio, 508. Llandeilo flags, 688. LoclceB tavern, 170. Logan C. H., 527. Lonaconing, Md., 408.

" Penn., 348.

Long Branch, 440.

" creek, 442.

island, Suunton river, 322.

Loudoun CO., 132, 134, 214, 46a Louisa, 719.

" 00., 61, 74, 78, las, 247,

Louisa C H., 454.

" road, 800. LouUville, Ky., 214, 231. Lovingston, 813, 481, 721. Lower Bee run, 870.

Machodoc, 429.

Virginia, 3, 5, 11. Lowerrc's, Mr., 446. Low Moor iron mine, 728. Lucado, 721. Lucca, waters at, 654. Lnckett*s, (Mr.) quariy, 469. Lunenberg, 286.

u C II 481 Luray, 126, 215,' 220, 221. Luzerne co., Penn., 622. LycU, Mr., 16, 89, 677, 632, 666. Lynch's, 722. Lynchburg, 81, 86, 88, 132, 287,

291, 297, 806, 320, 721, 727. Lynchburg June, 721.

Machodoo river, 429. Machadox run; marl, 152. Mack's mt., 206. " run, 164. Maclure, Prof., 646. Macdonald's coal, 408. Macfarlane, James., 733. Madison's cave, 723. Madison, 721. McAfee's knob, 219, 222. Makefree, 276. Maidenhead, 533.

Main St., Richmond ; infusoria, 452. Malyem bills, £ng., 638.

Manassas, 721, 723.

gap, 196, 769. Manchester crossing, 724. Manikintown ferry road, 483. Mann's, Mr. ; marl, 153. Margaretsville, 728. Marietta, 334. Marion, 728. Markham, 723. Marsden's, 659. Marshall, 723. " CO., 610. " Mr. J. ; marl, 47. Marsh run, Rappahannock, 468, 474. Martin group of ores, 685, 687, 700,

Martin, Mr., 637. Martin's, J. ; coal, 409. Martin's, 727. Martinsburg, 170. Martinsville, 307. Maryland, 5, 159, 195, 218, 254, 317,

348, 359, 420, 712, 718. Mason co., 244. Mason*s cove, 222. Mason's, Mr., 389, 422.

" John y. ; marl, 154, 385. Massachusetts, 602. Massanutten mts., 92, 158, 174, 196,

212, 215, 218, 220, 722. Massanutten valleys, 177. Massaponax river, 423, 424, 440,

Massenburg's hill, 887. Mathews co., 152. Mathias point, 128, 421, 435, 436. Matlock, Eng., 577. Mattapony river, 56, 68, 150. Maurertown, 718. Max Meadows, 727. Mayoox; marl, 166. Maysville, 812, 814, 481. M'Call's quarry, 141. McCienna's bridge, 269, 276. McClure, Mr., 26.

McHenry's thermal spring) 662, 681. Mclvor's, 721. McKelvy, Mr., 686. Meadow branch, 227, 423, 440.

" mt., 109, 115,872. Meadows, The, 297. Mechanicsville, 463. Mechum river, 719.

Mecbump creek, 800, 467. Mechunk creek, 80, 81, 82. Mehenin river, 251, 256, 269, 277,

888, 481, 725. Mecklenburg, 286. Mcnager, Mr., 519. Mercer co., 196, 248, 872. Mcrrjweather bridge, 84, 86. Mexico, 569. M'Oaheysville, 174, 220. Michacrs coal, 408. MichaePs (WUls and Michael*8 pit),

571, 578. Michell, Mr., 682, 688. Michigan, 722. Micle, Mr., 856. Middle basin, 849, 856.

" fork of Potomac, 848.

island, Ohio river, 608.

" mt., 158.

" Mountain belt, 610.

river; Cheat, 702.

" run ; Cheat, 685, 690. Middlesex co., 44, 47, 130, 152. Middlctown, 718. Midland, 721. Midlothian mine, 69.

" new shaft, 571, 572, 578. " pit, 64, 69. Miffling CO., Penn., 618. Milford, 584, 724. Millboro, 719.

sulphur Rprfng, 99. Miller's furnace, 530. Mill creek; Cheat, 850. " " coal, 406. Jackson oo., Penn., 606. Milllgan's creek, 109. Millington, Mr., 10. Mill mt., 98, 102, 248, 685, 690, 592,

Mill mt. spring, 688. Mills's mines, 64. Mills and Reid's creek pit, 588, 670,

Millwood, 215. Milton, 720.

Minor's, Dr. ; marl, 153. Mississippi river, 6, 167, 817. Missouri, 817. Mitchell's, 721.

ford, 182. MitcheU's, Mr. ; coal, 518.

(i

Mohawk river. New York, 602. Molly's creek, Campbell oo., 822. Monmouth co., N. J., 119. Monocacy river, Maryland, 475. Monongahela river, 844, 864, 414,

491, 494, 503. Monongahela valley, 117, 870, 486,

498, 508, 610. Monongalia co., 880, 844, 868. " Penn., 248. coal basin, 117, 408. glades, 869. Monroe co., 161, 181, 185, 196, 201,

248, 269, 277, 887, 872, 887. Montgomery co., 94, 99, 126, 186, 189, 160, 170, 196, 209, 216, 218. Montgomery co., Maryland, 468. Montour's ridge, Penn., 620. Montpelier, 466, 467, 473. Monumental church, Richmond; fair

fusoria, 451, 462. Moon's, Mr. J. D., 801. Moorefield, 125, 132. Moorfield, old road, 249, 866. Moore, Mr., 698. Moravian Town, 722. Morgan co., 161.

" ford, 296. Morgantown, 848, 867, 884, 410, 491,

498, 506. Morgantown coal, 486.

" road, 871, 697.

Morton's coal, 409. Morton, Dr., 70. Morton mill, 327. Morton's mine, 76. Mossy creek, 94, 7, 217, 680. Motley's, Mr., 153. Mountain creek, 468, 474. " lake, 726. " run, 182, 462. Mount Pleasant, 80. Mount Jaclcson, 718. Mt. Vernon, 860, 440, 441, Airy, 826. " Carmel, 399. Carmel basin, 369. Crawford, 892. Meridian mills, 94. " Poncy, 479. " Ptuart, 486. " Torrcy, 168, S|07, 208. Muddy creek, 861, 868, 365, 867.

Muddy creek mt., 21, 109, S28.

" run, 466, 474. Hullica HiU, 1, Murohiaon, Sir R., 577, 687, 640, 647,

Murray, Mr. Daniel, 216. Murreil's, Mr., 360. Musquito Point, 431.

KaiiBemond oo., 154, 248, 886.

" river, 150, 154, 261, 266,

269, 273, 276, 886. Kap*B creek, 177.

" " Bprinp, 684. Narrowback mt, 228, 722, Nassau thermal springs, 677. National road, 514.

Natural Bridge, 206, 216, 726. Navy Yard, 710. Neabsoo creek, 441. NeaFs, Mr. ; marl, 168. Negro mt., 359, 861. " " axb, 621, Nelson co., 86, 88, 92, 281, 286, 290,

294, 296, 320, 890. Nelson's (Mr.) estate, 469. Ncuewelt, Germany, 668. NeviPs (Mr.) estote, 356. Newark, 468. New Baltimorei 476. Newbem, 228. New Brunswick, 819. New Canton, 78, 80, 287, 802, 811,

Newcastle, 61, 62, 64. New Creek mt, 161.

creek, 854.

" Egypt, 7, 9.

" Fork church, 442.

Found river, 442.

" Glasgow, 721.

" Jersey, 87, 196, 254, 286, 817,

602, 608, 712. New Jersey greensand, 8, 6, 59.

limestone, 94.

" Kent CO. ; marl, 43, 46.

" London, 297, 482.

Market, 82, 126, 170, 172, 212,

220, 294, 802, 442, 474, 522, 718. New river, 109, 116, 121, 189, 166.

196, 217, 872, 604, 726. NewBom's, 728.

New York, 161, 197, 200, 214. Nichol's, Mr., 616. Nicholson's mill ; marl, 387. Nippenose valley, 614. Nittany valley, 614. Nixon's, Mr., 52. Noel, 719. Nokesville, 721. Noland's fcrrv, 472, 478. NoHTolk, 727.*

CO., 248, 266, 266. Norris group of ores, 691.

coal vein, 701,706. North Anna river, 26, 29, 487, 440,

North branch of Potomac, 869. Northbury, 28, 51, 62, North Carolina, 81, 261.

" eocene, 58.

" Mne, 121.

" Danville, 722. Northern Neck, 126, 180, 419, 426. North Fork mt, 161, 176, 178, 181.

" Garden, 721. Northamptom co., 417. North Holston valley, 140. North mt, 27, 86, 92, 97, 101, 111,

219, 226, 616, 719. North river, 98, 214, 216, Y28. Northumberland co., 162, 419, 482.

C. H., 482.

Northwest turnpike, near Winches- ter; limestone, 622, 628. Nottoway, 728.

" C. H., 481, 727.

river, 261, 266, 261, 273,

277, 887. Nottoway swamp, 263, 273, 887. Nova Scotia, 819. Nowlan*s, 822.

Noyes, Hand and Co.'s coal, 880, 406. NuttaU, Mr., 647.

Oaks's, D. ; marl, 162. Oaks, Mr., 130. Oatland miUs, 469, 476. CXxxxjuan creek, 441. Ohio, 247, 260, 817, 333.

river, 116, 121, 191, 250,330,

844, 374, 388.

river ; section, 606.

" valley, 114, 332, 419, 486, 603. Oldtown creek, 618.

01iphant*s f arnace, 69& Oliver's coal seam, 407.

" F.; marl, 163. Opequon, 172.

Opossum creek, 287, 304, 892. Orange oo., 74, 81, 85, 126, 132, 318,

Orange, 721.

" C. H., 467, 473. 620. Organ% Mr. ; marl, 166, 166, 386. Organ cave, 108.

Osborne's ferry, James river, 448. Otter river, 306, 307, 891, 722. Owens creek, 294, 803. Oxford, Eng. ; day, 649.

Pacham, Ifaj ; marl, 889. Fader ; springs, 679. Paddy's cove, 684.

mt., 684, 590, 691. Paddytown, 348. Pagan creek, 160, 261,267,269, 272,

Page CO., 167, 173, 204, 207, 210, 216,

PalUsades, 317. Palmer's Col.; marl, 161. Mr., 431. Mrs. ; marl, 161. Pamplin's, 727. Pamunkey river, 17, 28, 48, 67, 417,

Pannel's bridge, 322.

" mill, 326. Pannlll, Mr., 468. Panther gap, 683, 687, 728. Paris, 464.

" basin, 16, 17, 19. Paris and Wood's coal bank, 406. Parke, Mr., 422. Parkersburg, 882, 344.

" on Ohio, 486.

Park's mill, 217. Paspi tansy creek, 436.

hills, 420.

Patrick, Mr., 881. Patrick CO., 26, 110, 121, 290, 807,

Patrick, C. H., 297, Pattonsburg, 344. Patterson's creek, 896.

" mt., 161, 178, 181.

Pattcson's quarry, 296, 818, 814.

Patuxent river, Md,, 726. Pcachy's (Dr.) estate, 47. Peak creek, 224.

Peaked knob of Draper's mt., 166. " Mt., 93, 168, 173, 176, 196. Peaks of Otter, 206, 416. Peak, The, 168, 174. Pearoe's furnace, 684.

" spring, 684, 691. Pearisburg, 109. Pedin's, James; marl, 164, 386. Pegram, W. H. ; marl, 388. Pendleton oo., 161, 163, 171, 176,

181, 195, 886, 604, 612. Peninsula, The, 26, 37, 39, 66, 125,

128, 180, 421, 483, 434, 733. Pennsboro', 614. Pennsylvania, 74, 134, 161, 175, 184,

196, 817, 332, 347, 869, 862, 369,

Pennsylvania anthradte, 100. limestone, 94.

line, 486.

Penola, 724. Perrow's, Capt., 390.

" Stephen, 306. Persill's, Mr. R. ; marl, 152. Peter's bridge, 277. Petersburg, 70, 80, 251, 261, 360,

862, 418, 437, 440, 448, 466, 481,

724, 727. Petersburg and Devil's bridge road,

Petersburg and Roanoke railroad,

Peter's mt., 85, 109, 111, 176, 394,

687, 693, 614, 628, 629, 719, 726. Peters's mt axis, 623. Philadelphia, 10, 670, 709. Phillips's, Mr. ; mari, 166, 886. Phillips, Prof., 68, 647, 649, 661, 666. Piedmont, 163. Pigeon creek, 627. Pigg river, 297. Pigsborough crk, 302. Pilot Mt, 168, 171, 206. Pine Barren, 9.

Piney Swamp country, 860, 361, 362. Pipe creek, Ohio river, 610, 617. Piping tree, on Pamunkey, 17, 19,

62, 667. Pittsburg, Fenn., 117, 843, 486, 498,

FinsyWank oo., 281, 290, 820.

turnpike, 306.

PlaiiiB, 728. Pleasant gap, 822. " Hill, 724. " Valley, 718. PocahontaB co., 161, 177, 181, 196,

201, 248, 886, 841, 872. Pooosin, 88.

Poootalico creek ; coal, 486, 498, 499. Pointer's, Mr. ; marl, 162. Point Lookout gap, 769. Point Pleasant, Mason oo., 882, 414,

485, 618, 626. Pollard's, Mr. ; marl, 168. Pomeroj's landing, Ohio river, 617.

seam. Ohio, 834, 498, 619. Pond mt., 464, 476, 723. Poor house, Richmond; infusoria,

445, 451. Poormts., 206. " Valley mt., 728. " ridge, 681, 726. PopUr camp furnace, 139, 209, 630. " " mt, 189, 163, 196, 208, 206, 628, 726. Poplar run, 473.

swamp, X. J., 119. Port Republic, 217. Port Royal, 17, 66, 486, 667. Portsmouth, 269, 334, 728. " Ohip, 606, 619.

Port Walthall junc., 724. Potomac cr., 7, 423, 435, 441, 444. " geological division, 604, 610, Potomac; marble, 86, 133, 472. " river, 12, 17,48, 117, 126, 179, 196, 204, 836, 848, 862, 418, 422, 440, 464, 474, 601, 711, 722. Potomac river ; limestone, 469. coal basin ; iron, 848. lower faUs, 24. " run, 724.

" south branch, 176, 179, 612. Potts (Heth, Potts and Co.), 633. Potts creek mt., 723.

" mt, 726. Pottsville coal field, 614. Pounce's tract road, 483. Pounding mill, 890.

" creek, 802.

Powell's creek, 259, 262.

Powhatan, 481, 726.

" CO., 27, 126, 261, 414. coal, 480, 633, 634. Prentice's, Mr. ; marl, 166, 389. Presl, M., 666. Preston axes, Penn., 868.

" basin, Penn., 868.

coal basin, 408.

CO., 869, 862, 869. Preston's salt well, 142.

spring, 664.

Pretlow, Jos. ; marl, 387.

" Robt, 387. Price, Mr., 866. Price's, Mr. ; coal, 409. Price's mt, 229, 230, 892.

road. North mt; limestone,

Pricket's creek, 491. Pridevale Iron Co., 681.

coal, 701. Prince Edward CO., 27, 69, 281, 284,

289, 818, 820, 826. Prince Edward 0. H., 816, 827, 480,

Prince George co., 47, 61, 166, 261,

262, 889, 662. Prince William co., 182, 817, 469. Princess Anne co., 266, 257. Prop's Gap mt, 161, 162, 178. Prospect, 727.

Prospect Uill creek ; aiarl, 152. Pruntytown, 410. Pughtown, 226. Purbeck, 641. Purcellville, 729. Purdie's, G.; marl, 154, 386. Purgatoiy mt, 196, 20C, 218, 221,

Pyrenees ; thermals, 589. Pyrmont springs, 677.

Quantico, 724.

" creek, 440. Quarry branch, 806. " hill, 684.

" run. Cheat, 371, 686, 686, Quebec ; geological division, 722. Quinnimont, 720.

Raccoon creek, 258, 273. ford, 461, 478, 479.

it

mt., 88, 205.

Point, 430. Raine's tavern, 823, 326. Rand (Xoyefl, Rand and Co.), 880, 406. Randolph*s, Capt. Thomas M., 684. Randolph oo., 184, 201, 248, 836,

860, 417, 604. Rappahannock, 721. Rappahannock clififB, 127, 480. 00., 182, 133. mt.,461, 466, 466. river, 7, 17, 48, 126,

130, 417, 421, 483, 440, 466, 460. Rappahannock, north fork, 474. Rapidan river, see Rapid Anne. Rapid Anne river, 132, 134, 461, 467,

473, 620, 721. Rattlesnake creek, 320, 322. Raven rocks, 491, 684, 704. Rawley springs, 101, 228, 669, 722. Rawlings, Mr., 467. Rawlings' quarrj, 620. Read creek, see Reed. Reams, 724. Rectortown, 723. Red creek, 349, 361. ReUeeld, Mr., 647, 668. i

Red UiU, 721. House shoals, Kanawha, 632. " springs, 107, 688. Sulphur springs, 106, 109, 662. Reed creek, 189, 240, 629, 623. Recve*s, Mr. ; marl, 389. Reid bridge, 322, 326. Reid's creek, 828. Reid's (Mills and Rcid's creek pit),

638, 670, 673. Rennet-bag creek, 88. lietreat, 62.

" furnace, 222. Reynolds and Donally, 380. Reynolds's quarry, 138, 169. Rhenish provinces. The, 640. Rhine creek, 860. Rhodes* gap, 24. Rhodoheaver, Mr., 368. Rioe*s 727.

Riceville, 321, 322, 326. Rioe*8, Walter; marl, 162. Richland, 724. Richmond, 60, 66, 69, 79, 116, 194,

261, 280, 800, 439, 442, 449, 464,

666, 660, 709, 711, 719.

Richmond co., 127, 161, 419, 430. Richmond, Fredericksburg and Poto- mac Junction, 719, 726. Richmond, old road, 804.

" tunnel, 726. Rich mt., 614.

Rich Patch mt, 101, 102, 108. anticlinal, 719. valley, 728.

" Valley, 893. Ridgway, 482.

Ridgway, Mr. Thomas S., 413, 640. Ridley's, Maj. ; marl, 387, 888. Ringgold, 726. Rivanna river, 84, 289, 465. River station, 723.

Hill, 611.

" pit mine, 64. Rives's quarry, 892. Roane's, William H., 52, 64, 60. Roanoke, 725, 727. " CO., 209, 216. river, 482, 684, 623, 711. Roaring creek, 861.

" run, 896, 728. Roberts, Capt., 468. Roberts's mill ; marl, 162. Robertson, Wyndham, President of

Board of Public Works, 124. Robertson river, 461, 473, 474. Robms's Mill ; marl, 152. Robinson's, Capt. Jas. ; marl, 161. Rockbridge oo., 27, 79, 93, 96, 138,

Rockbridge Alum Spring (Alum

Spring), 668, 723. Rockbridge baths (Stricklcr's spring),

Rocketts, 442, 448. Rockfish, 721.

gap, 89, 91, 206, 462. river, 295, 301, 818, 318. Rockingham co., 93, 183, 207, 218. Rock Point, Appomattox river, 448. Rocks, The, 164, 886. Rocky mt., 807, 812, 482.

Point, 442.

Rogers, Prof. H. D., 89, 69, 86, 100,

119, 134, 166, 191, 817, 338, 362,

586, 647. Rogers, Prof. J. B., 166, 191, 248,

846, 418, 589, 666.

ti

Rogers, R. E., 768.

" Prof. W. B., 22, 124, 688,

783, 786, 769. Rogeres coal seam, 406. mill, 899, 492. Roll's, Mrs., 426. Romnej, 179, 628. Ronceverte, 720. Rose, Prof. H., 10, 39, 369, 862. Ross's furuaoc, 88, 804, 811, 392,

Ross iron ore, 686. Round Hill, 729. Rowan's, Dr.; marl, 162. Rucker's run, 296, 813. Ruffin, N. C, 726.

Ruffin, Mr. Edmund, 16, 17, 19, 666. Ruffin's, Mrs., 62, 64. Ruffner, Daniel, 382, 407.

Mr. Lewis, 380, 406. Rural Retreat, 727. RusseUoo., 139, 166, 196, 816, 837.

" C. H., 630. Russia, 687. Ruthcrfoord, John, President Board

of Public Works, 638. Ruther Glen, 724. Ryder's creek; section, 376, 876,

Roland's, Mr. ; marl, 168.

Salem, 727.

Sallna ; geological division, 717. Sailing's mt., 204, 206. Salt Lick, 360. " Pond mt., 109, 726. " Sulphur springs, 106, 108, 109,

Saltville, 726. Sampson's mill, 483. Sandford, Mrs., 463. Sandy and Beaver canal, 608. Sandy bridge, 369.

" ford, 323.

" mt, 181.

" river, 195, 416, 484. Sappony creek, 483. Saunders's, Judge, 306, 391. Saunder's, Mr.; marl, 161, 163, 164,

Savage mt., 848, 349, 360.

" river, 348, 362, 865, 407. Sawratown, N. C, 321.

Sawyer's, Mr., 139. Scarborough, Eng., 668. SchaefFer's, Mr., 860. Scioto valley, 832. Scotland, Great Britain, 186. Scotland Banks, 163. Scott CO., 166, 201, 213, 216. Scottsburg, 726. Scott's creek, 807. " mUl, 276, 306. " ore, 696. " pit, 636.

" run, 871, 486, 494, 498, 600, 602, 608. Scottsvillc, 86, 132, 291, 293, 301,

320, 463, 467. Scrabble croek, 374, 377. " coal, 406.

Seaboard, 728. Seaport's (Mr.) land, 869. " " coal, 409.

Sedgwick, Prof., 637, 640, 720. Seigen, Germany, 640. Selby's Port, 362, 367. " " road, 863. Sample's, Dr. ; marl, 47.

" Judge ; marl, 4, 46. Seneca creek, 184.

" Md., 474. SewellMts., 118, 248. Sewall'8 Point, 262. Seybert, Mr., 8. Shadwell, 721.

Shannondalc springs, 101, 178. Shaw's ridge, 182. Shawsville, 727. Sheet's Hollow, 701, 704. Shenandoah, 718.

" Co., 27, 99, 173, 176,

210, 228. Shenandoah Iron Works, 207. " mt., 182, 183.

" river, 196, 204.

" river, Page co., 622.

valley, 92. Shepherdstown, 93, 138, 169. " quarries, 216.

Shillingberger, Mr., 366. Shirley, 260. Shockoe creek, 442, 450.

" hill, Richmond; infusoria, 460, 461, 452, 736. ShortHm,4&6, 611, 623.

Short HiU mt, 196, 209, 218, 221.

" " ore, 240. ShreeTe*B, Col., 477. Shrewsbury, 7. Shrewsbury, CoL Joel, 878, 879.

" Mr. WiUiam, 380.

Shumate's, 478. Sideling hill, 719. Sigler's mine, 408. Silliman, Prof., 650, 667. Simmons gap, 168. Sims's (Mr.) slate quarry, 79. Sindree earthquake, 685. Singing cave, 108. Sinking creek, 386, 839.

" valley, 614. Skinquarter creek, 488. Slade, Mr. I., 192, 418, 416, 640, 763. Slate river, 79, 814. Sleepy creek, 99.

" mt., 226. hole ferry, 154, 166, 268, 269,

Sliding hill, 613, 617, 618. Smith, Christian, 399.

" Mr. C, 861.

Capt ; marl, 47.

Maj., 806,

Smithficld, 12,' 218, 269, 276, 862,

868, 664. Smith's mt., 807.

" point, 420.

" river, 821, 824. Smither'tf creek, 876, 877. coal bank, 407. Smoky or Unaka mts., Tenn., 602. Smyth CO., 126, 139, 209.

" C. H., 617. Snake-den ores, 698, 694, 700. Snake Run mt., 687, 688.

" springs, 681. Snickers gap, 769. Snow creek, 424, 440. Snowy creek, 860, 861. Snvder's mill, 364, 866, 866. Soldiers' Uome, 710. Sour Spring, at White Sulphur, 669. South America ; earthquakes, 682. South Anna river, 26, 29, 63, 800,

437, 441. South Branch ml, 161, 179, 181. South downs, Eog., 641.

Southampton co., 248, 277, 887. South mt., 608, 610.

" " Berks co., Penn. ; scctioiiy

South river, 95, 208, 216, 723. Southwest mt., 62, 72, 77, 81, 87,

285, 456, 458, 460, 466, 473, 719. Spottsylvania co., 74, 125, 428, 424. Springfield, 721.

coal pits, 446. Springfield and Deep run coal basin,

Springhill furnace, 695. 'Sprisc Hill, 420, 433. Spruce ridge, 849. Stafford co., 129, 132, 419, 423.

" C. H., 424, 438, 441. Stag creek, 441, 446. Stage road, Shenandoah co. ; lime- stone, 621, 623. St. Albans, 720. Stamping creek, 837. Stanardsville, 454, 473. Staunton, 138, 174, 216, 718, 719. river, 288, 807, 811, 822,

482, 722. Steinbergen, Gen. ; coal, 618. Stephens city, 718. Stephens, Dr., 305. Stephenson's, 718.

Sternberg, M., 647, 649, 651, 664, 667. Steubenville, Ohio, 606. Stevensburg, 464, 474, 478, 479. Stevens's creek, 302. Stewart's knob, 312. Stifft, 677. Still Uouse branch, 423, 440.

" " creek, 463. Stillwell's, Mr., 699. Stith's, 166, 886. Stith, Mr. D. ; marl, 48. Stithes', see Stith's. St. Lawrence river, 601. St. Leger farm, 482. St Mary's river, Md., 664. Stockton's coal, 876, 878, 406.

steam mill; section, 875,

Stone Coal gap, 894. Stone, Mr., 443. Stone mt., 196.

" run, 212. Stoncsfield limestone, 649.

Stonehenge, 538. Btonej Han, 184, 205.

Point, Blue Ridge, 464. river, 849, 856, 858, 408. " run, 851. Stonewall creek, 804, 811, 892, 527.

millB, 86, 87, 88. Stonj creek, 614, 724. Strasburg, 94, 158, 172„ 215, 217,

220, 723. Strasbuig Junction, 718, 723. Stratford cliffn, 151, 420, 428, 433,

Stratford group of ores, 689, 691,

Strickler*8 gap, 225, 584, 723.

spring (Rockbridge bath),

Strouble's run. Ill, 186, 229, 726. Stuart, Maj., 172. Studtzard ; fossils, 649, 650. Sufifoik, 12, 154, 886, 664, 727,

Suffolk 00 , 252, 256, 258, 269, 276. Sugar hills, 591. Sugarland creek, 476. Summerduck creek, 468. Summers* (Judge), bank, 526. Summit, 726. Sunderlandshire, 646. Sunfish creek, Ohio river, 518. Surrey oo., 30, 42, 47, 155, 248, 251,

277, 886, 672. Surrey hills, 641. Susquehanna ; geological divisfon,

604, 610, 617, 622. Susquehanna river, Penn., 602. Sussex CO., 248, 277, 388. Suttonsville, 541. Swanks, Ur. James; coal, 618. Sweet Hall, 726. Sweet springs, 104, 107, 111, 229,

521, 588, 725. Sweet Alum springs, 681, 586.

Chalybeate, see Sweet springs,

Honroc oo. Sweet Springs, Alleghany co., 568,

Sweet Springs, Bath co., 565.

Springs, Monroe co., 562.

Spring mt., 105, 687, 628.

Springs valley, 104, 106, 181,

678, 587, 592, 615, 725.

Swift island, 802. Swift creek, 482, 483.

run gap, 134, 205, 454, 456,

Swisher iron ore, 693, 701. Swoope, 719. Swope's knobs, 725. Sycamore, 722.

" creek, 297, 807. Sypole run, 865, 367.

laconic mt., 606.

Talcott, 720.

Taliaferro, Dr. ; marl, 46.

'' Mr. Francis, 444. Tarbay, 17, 55, 60, 155, 260, 889. Tardy, Capt, 807, 891. Taunus mts., 640. Taylor, Mr. Richard C, 645, 647. Taylor's copper mine, 87. Taylorsville, 445, 724. Taylortown, 469. Tazewell, Littleton W., Pres. Board

of Public Works, 22. TazeweU co., 165, 195, 216, 887. Temple's, 724.

Ten Mile cr., Kanawha, 518, 524. Tennessee, 195, 206, 209, 817, 833,

602, 608, 728. Tennessee line, 135, 616. Terrapin creek, 887.

swamp, 887. Teutoberges-wald, 579. The Blooroary, Capon mt., 581. The Horseshoe, 850. The Neck, 126, 130. The Peninsula, 421, 425, 427, 434. The Pyrenees, 577. The Two Pointers (mts.), 395. Third HiU mt., 226, 227. Thom's creek, 136, 490. Thornton, 729.

Thornton's gap, 168, 205, 454, 462. Thoroughfare, 723.

gap, 464, 475. " hill, 380.

hollow, 379.

Thrashly's farm, 424. Three Chopped road, 483.

" creek, 258, 273, 277.

" Fork creek, 364, 369.

Mile creek, Kanawha, 527.

Three Topped mt., 158.

TbunnaxL M., 639.

Thurstons, Mr.; marl, 158.

Thurston's, Mrs. ; marl, 47.

Tilgatc limestone, 649.

Tinker's mt., 196,219, 222, 725.

Tinder's gold mine, 723.

Todd's, Mr. Merit; marl, 154, 885. " quarry, 620.

Tolersville, 719.

Tomlin's, Braxton; marl, 161.

Tomlin, W., Esq., 488.

Tomlin's, Walker, 62, 64, 60. Williamson; marl, 161.

Tomlinson's run, 509.

Tom's brook, 718. " creek, 229, 726.

Tour Hill, 728.

Townhill, 182.

Town Point; marl, 154, 385.

Torbaj, see Tarbay.

Tower Hill, see Tour HilL

Towson, Mr., 448.

Traa fork, 627.

Trabuc's pits, 181.

Trap Dyke, 892.

Traveller's Rest, 801.

Tribbet's mill, 497.

Triple Fork, gold mine, 723.

Triplett, Mr., 73.

Troost, Prof., 611.

Tuckahoc, 66.

" coal basin, 465.

creek, 63, 64, 68, 488.

Tucker, Prof. ; limestone, 806, 807.

Tumbling run, 172.

TunsUll's, 726.

Turkey river, 474.

Turk's gap, 24, 89, 168, 204, 462, 769.

Turner's mill, 462.

Tuscaloosa, 605.

Tutwiler's, 108.

Twelve Pole creek, Ohio river, 611.

Twenty Mile creek, 877.

Two Mile creek, Kanawha ; lime- stone, 624, 626.

Tye river; marble, 81, 83, 302, 818,

Tye River pap, 200, 312, 481, 769.

Tygart's Valley river, 117, 864.

Tyler CO., 384, 610.

Tyler's creek, Kanawha; limestone,

Tyree's coal bed, 406. Tyson, Prof., 712.

Ullah Bund, 635. Unaka mts., see Smoky mts. Union, 109, 524, 623. Union Hall ; marl, 48.

" iron works, 312.

mills; marl, 151,463.

" mine, 66, 76. Untontown, 108, 109, 360, 861, 485. United States arsenal, 482. University of Virginia, 22, 89, 186. Upper GMpoke creek, 165. Urbanna, 47.

Urquhart, Mr.; marl, 388. Utt ore, 694.

Valley, The, 24, 27, 110, 112, 116, 196, 204, 211, 224, 292, 297, 587, 603, 624, 722, 726.

Valley, The ; boundaries, 203. " furnace, 404. " river, 606.

Vandiver, Mr., 355.

Vandover's, Mr. ; coal, 854, 408.

Van-Lew's, Mr., Richmond ; infu- soria, 462.

Van Meter's, Mr. ; coal, 354.

Variety Mills, 88, 314.

Vaucluse, 718.

Vestal's gap, 769.

Vicat, M., 280.

Vienna, 729.

Vineyard hill ooal, 882, 888.

Wade's, Mr. ; marl, 47. " coal bank, 500. Wadesville, 718. Wakefield, 156, 886, 727. Wales, Great Britain, 29, 136, 687,

Walker, Mr., 88. Walker's, Mr. Benj., 151,482.

creek, 141, 179, 684, 624.

" vaUey, 140. ford, 801, 804. rot.. Ill, 140, 165, 178, 204, 726. Walker's Valley springs, 584. Wallace's (Mr.) quarries, 443. mUI, 441.

it (i

Wall's, Mr., 869.

" (Mr.) coal, 410.

bridge, 887. Wallers Mill ; marl, 36. Walton, W. S., 826, 827. Walton's gold mine, 723. Ward's, Mr., 806. WardensYille, 684. Ward's springs, 722. Wardour, Vale of, Eng., 641. Warehouse creek, 162. Warminster, 81, 82, 86, 801, 802,

814, 320, 390, 467, 481. Warm springs, 667, 665, 680, 686,

686, 723, 724. Warm Springs anticlinal, 719.

" " creek, 686.

" mt., 99, 108, 161, 176,

181, 686, 724. Warm and Hot Springs, anticlinal

Talley, 614, 719. Warm Sulphur springs, see Warm

springs. Warm Spring ridge, 690.

" Springs Talley, 99, 101, 106,

171, 174, 176, 181, 692. Warren, 829. Warrcnton, 454, 460, 465, 474, 478.

" June, 721.

Warth and English's coal, 407. Warwick's If t. gap, 296. Warwick co., 166. Washington, D. C, 70, 86, 448, 709,

711,724. Washington co., 126, 209, 216, 219,

226, 229. Washington co., Penn., 606. Waterford, 639. Water Lick, 723. Watery mt., 466. Waterloo shaft, 636. Watsontown, 688. Waveriey, 727.

Waynesborough, 216, 894, 719. Wealden district, 641. Weaver, Mr. Thomas, 637, 689. Webb's, Conrad ; marl, 60. Weegee creek, Ohio river, 610, 618,

Weldon, 724, 728.

" N. C. ; section, 482. Wells, Mr. M., 640,

Mr., 494.

(I

Wella, Samuel, Esq., 733, 734, 786. WellaviUe, 727.

" on the Ohio ; section, 608. " ferry, 608. Welsh (Friend, Welsh and Co.'b

mines), 627. Western branch, 269.

coal basin, 868. Westemport, Md., 196, 336, 337, 848,

862, 408. Westemport, Fenn., 848. Western Sussex, Eng., 641. West Laurel hill, 621. Westmoreland oo., 161, 419. Westphalia, Europe, 640. West Point, 726. Wethered, Mr., 469. Weyer's Cave, 94, 216, 728. Wheeling, 117, 848, 601, 612, 616. coal seam, 401, 486, 498. creek, 612, 613. hill, 614. Whipping creek, 288. Whispering creek, 812. Whitby, Ikig., 646, 649, 663. White Day creek, 490, 491. White House, 726. Whitehurst, on waters of Matlock,

White mts.. New Hampshire, 601. White Oak creek, 821, 326.

" " mt., 821, 826, 826, 878.

" Plains, 172, 469. White's gap, 769. White's, Mr. ; marl, 164, 385. White Sulphur springs, 24, 106, 106,

181, 183, 460, 660, 678, 681, 688,

White Thorn creek, 822.

" tavern, 322. Whitetop mt. gap, 769. Whitely, Mr., 468. Whitley's quarry ; limestone, 619. Whittle's, 722. Wickham's, Mr. ; coal, 62, 63, 68.

" Wm., 66.

Wigmore lake, 688. Wilkcsbarre ; fossils, 660. Wilmington, Del., 712. William and Mary College, 8, 7, 9. Williamsburg, 4, 13, 30, 86, 40, 66L

662, 663, 669. Williamson, Mr., 666.

it

Willoughby's Point, 262. WilPa creek, 847.

mt. azUy Penn. 847,

613, 620. WilU's pit, 683.

Will's and MichaePs pit, 671, 673. Willis's mine, 63.

mt., 69, 71, 80, 286, 290,

812, 814. Willis's river, 820. WUson'B, 727.

Col, 827.

mill, 364, 404.

thermal, 663, 681, 689,

Winchester, 92, 172, 173, 474, 621,

623, 718. Winchester springs, 178. Winding ridge, 361. WindmiU point, 432. Windsor, 727. Winston's, Mr., 441. Winterpock creek, 482, 634. Wintioomack creek, 482, 483. Witcher's creeks, 874, 378. Wolf, Mr., 866. Wolf creek, 394, 626, 684.

axis, 614, 620, 624. mt., 176, 614, 620. run, 860. Wood CO., 844, 610. Woodgrove furnace, 681, 683, 694,

Wood's, Mr., 208, 277, 888.

James S. ; ore bank, 289. Wood's (Paris and Wood's bank),

Wood's mt. (misnamed Appomattox),

Woodstock, 172, 212, 216, 221, 895,

422, 718. Woodstock road, 622. Woodward's, 636.

coal pits, 483.

Woolley, Mr., 119. Worcester co., Mass., 762. Wormley's creek, 37. Worth, Col., 678. Wright's, Mr., 890. Wyke, Eng., 649. Wynn's, Mr.; marl, 47, 166. Wythe CO., Ill, 118, 139, 160, 168,

171, 196, 209, 216. Wythe C. H., 223. Wytheville, 726.

Tancey, Maj. ; limestone, 801. Yancey's diff, 314. Yeatman's, Mr., 311, 627. Yellow Springs, 101.

Sulphur springs, 668. Yerlcy's, Mr. ; marl, 161. York, 88, 44 116.

" Co., 82, 48, 47; 48.

cUff ; marl, 48.

" river, 4, 80, 121, 126, 268, 426. Yorkshire, £ng., coal fields, 68, 64tt,

Yorkshire ; geology, 64, 666. YoriEtown, 4, 12, 87, 271. Youghoganey river, 848, 361, 862.

Zuni, 727.

ZobUlz, Saxony, 764.

The Cnd.

WORKS ON GEOLOGY, Etc.

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