The Iron Ores of Minnesota

N.H. Winchell & H.V. Winchell · 1891 · Iron & Steel

Classic study of the great Lake Superior iron ore districts — Mesabi, Vermilion, and Cuyuna ranges. Geology, discovery, and early production data through…

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I -I . I

Geological And Natural History Survey Of Minnesota.

N. H. WINCHELL, State Geologist.

WfS-4

Bulletin No- 6.

Thk

Iron Ores of Minnesota,

Ti1Kik

Geology, Discovery, Development, Qualities and

Origin, and Comparison with those of

other Iron Districts,

With A

Geological Map, 26 Figures And 44 Plates.

BY X. H. WIXCilKLL AND H. V. WINCHELL.

MINNEAPOLIS: Hakhison & Smith. State Printers.

1H01.

The Iron Ores Of Minnesota.

Contents.

Pago.

Preface vii

Part I.

Their Distribution And Geology.

Reoentneas of the development of the Minnesota ores 1

Changes and Improvements 2

Sketch of what the earlier Minnesota reports have said 4

(1). The magnetites of the Ynrrmlion nrnistn- 6

(a). Nature of the enclosing rocks.

(1). Macroscopic 7

(2). Microscopic 8

(3). Structural features 10

(6). Qualities of the Vermilion magnetites

(1). Chemical 11

(2). Origin of the Vermilion magnetites 11

(c). Probable parallels in other parti of the United States 23

(2). The hematites of the Eeewatin schists.

(a). Nature of the enclosing rooks 24

(1). Macroscopic characters 36

(2). Microscopic characters of the enclosing schists 38

(6). Structures and character of the hematites of the KeewatiD 47

(1). Structural features of the ore 47

(2). Mineral associations 67

(3k Microscopic characters of the jaspilyte 71

(4). Qualities of the Eeewatin hematites 81

(5). Origin of the Eeewatin hematites 105

(3). The ores of the Taoonic .

(a). Reasons for substituting this name for Animike 113

(6). Nature of the enclosing rocks.

(1). Macroscopic 113

(1). The quartzose- horn blende or (olivinitio) magnetite group 117

(2). The impure jaspilitic-hematite-aud-limonite group 120

(3). The carbonated: iron group 121

(4). The gabbro-titanic iron group 128

(2). Microscopic characters of the enclosing Taoonic rocks 126

(3). Structural features of the ores of the Taoonic 130

(c). Nature and origin of the Taoonic ores 137

Chemical composition 138

The use of titauic ores 142

Origin of the Taconic ores 144

(/). Probable parallels of the Taconic ores in other parts of the U. S. 146

(4). The limonites of the Cretaceous v 151

(5). Geographic distribution of the crystalline iron ores of Minnesota. . . 154

6). Comparisons with Michigan and Wisconsin. 157

7). Synoptical review and outlook for the future 161

iv CONTENTS.

Part Ii.

METHODS OP EXPLORATION AND MINING, AND DESCRIPTIONS OP THE VARIOUS MINES

Early methods of exploration 165

O u tfit 168

On the ground 171

The diamond drill 171

The first test-pitting and mioirg 175

Methods at the mines 176

Drills 178

Explosives 179

Hoisting apparatus 180

Timbering 181

Ventilation 182

Equipment 182

Methods of sampling and analyzing 186

Distribution of phosphorus in the ore 191

The Minnesota mine 193

The Chandler mine 196

The Pioneer mine 198

The Zenith mine 200

The Anderson mine 201

The Mallmann mine 202

The Diamond mine £05

Part Iii.

The Transportation Of Minnfsota Ore.

Duluth & Iron Range R. R 208

Facilities at Two Harbors 209

Market prices of iron ore 21 1

Profits. 212

Part Iv.

Origin Of The Orbs Of Iron.

Growth of theories 213

Bog iron ores 221

Crystalline iron ores. A 223

Classification of theories 224

Discussion of theories 225

Concluding observations. 255

List of advocates of the various theories 256

Part V.

Bibliography of the origin of iron ores 258

Part Vx

List of mining companies incorporated under the laws of Minnesota 335

Leases of mineral lands under the law of 1889 350

Part Vii.

Mining laws and regulations 356

PART vni.

Glossary of mining and geological terms. 362

Appendix A.

On a possible chemical origin of the iron ores of the Keewatin in Minne- sota 891

Appendix B.

The Taconic iron ores of Minnesota and western New England 400

Appendix C.

The eastern equivalents of the iron ores of Minnesota 411

Appendix D.

List of rook samples referred to in this bulletin 420

Index 423

List Of Plates And Their Places.

To face page- Plate I. Crumpled green schist, Tower mine 38

Plate II. Contorted jaspilyte, north slope of the north ridge 54

Plate III. View north of Tower, to show the gradual interst ratifi- cation of the jaspilyte and schist, and the stretched condition ofboth 56

Plate IV. "Tributary dyke" of hematite, Stone mine (No. 3), Tower, 57

Plate V. Microscopic characters of the Vermilion and Keewatin

schists* 46

Plate VI. View in the Stone mine (No. 3), showing vertical transi- tion from jasper to hematite 63

Plate VII. Shapes and disposition of the silica grains in jaspilyte

( Rock 867 ) 73

Plate VIII. Microscopic sections of jaspilyte. Figure 1 is from rock 876, magnified 250 diameters, showing the appearance between crossed Nicols. Fig. 2 is from rock 1565, magnified about 300 diameters, showing supposed dolomite grains mingled with the silica grains 76

Plate IX. Microscope sections of the siliceous green schist from north of the Tower mine, showing cotemporaneous deposition of the elements of the jaspilyte and of the green schist. Rock 1571, 80

Plate X. Map embracing the vicinity of the Vermilion iron mines.

In the cover Docket.

Plate XI. Breccia of jaspilyte cemented by jaspilyte. To face page 58

Plate XII. Plan of No. 3 pit, Minnesota iron company. vOld Stone

mine) 66

Plate XIII. Plan of No. 5 pit, Minnesota Iron Co. (Old East Ely

mine) 66

Plate XIV. Plan of the Pioneer mine, Ely In the cover pocket- Plate XV. Generalized section from Vermilion lake to Penokee Gap.

To face page 157

Plate XVI. Pioneers of the iron discoveries 165

Plate XVII. Alexander Baker starting for Fort Francis. Style of

winter supply train, 1885-6 166

Plate XVIII. Portage scene between Mud and Burntside lake, Sept. ,

Plate XIX. Shafting drill. American Diamond Rock-boring Co.. . 173

Plate XX. First blast in the Vermilion Iron range. Stuntz and

MallmanD, near the Lee mine 175

Plate XXa. Hoisting plant. E. P. Allis and company, Reliance

Works, Milwaukee, Wis 181

Plate XXI. Inclined hoist from the open pit, and shaft timbers for

perpendicular hoist, Chandler mine, Ely 176

Plate XXII. Open pit of the Chandler mine, Ely, showing drifts

from which ore is being taken 176

Plate XXIII. Chandler mine, Ely, showing open pit, and entrance

to the underground work 176

Plate XXIV. Self-dumping car, Tower 176

Plato V contains six figures, three of which, on the left, are from rooks 417 (II), 41* (II). and 1446, from the Vermilion schists. The three on the right are from rooks 9W. 998 and WJ8 A. and are from the Keewatin schists.

Vi List Of Plates.

Plate XXV. Hoisting shaft. Pioneer mine, Ely, showing a loaded

car on the way to the dump 176

Plate XXVI. Stock piles. Chandler mine, Ely 176

Plate XXVII. Ore pocket, Tower mine 176

Plate XXVIII. Loading iron ore at the Chandler mine. From the

pocket to the railroad car - 176

Plate XXIX. Reynolds' improved air-compressor, E. P. Allis& Co.,

Milwaukee 176

Plate XXX. " Slugger " rock-drills, Rand Drill company 176

Plate XXXa. Ideal perpendicular section of a mine, showing shaft, levels, timbering, engines for hoisting and compressing air, and method of drilling by power-drills. Rand Drill company 182

Plate XXXI. "Ingersoll Eclipse" rock drill, Ingersoll-Sergeant

Rock Drill Co 176

Plate XXXII. Little Giant rock drill, Rand Drill Co 176

Plate XXXIII. Sinking a large shaft with Ingersoll drills 176

Plate XXXIV. Excavating for a tunnel or driving a gallery with

Ingersoll drills 176

Plate XXXV. Sectional view of Ingersoll Eclipse drill 176

Plate XXX Va. Miner's candle, with jaspilyte breccia 17!>

Plate XXXVI. Double cylinder reversible link-motion hoisting engine, with fixed drums and double band brakes. Ingersoll- Sergeant company 176

Plate XXXVI. Condensed profile of the Duluth and Iron Range

railroad, from Duluth to Ely 208

Plate XXXVIII. Ore-car. Duluth and Iron Range RR., Tower. . 208

Plate XXXIX. Locomotive of the ore trains, Duluth and Iron

Range R . R 208

Plate XL. Section of the Kiowa (Kansas) meteorite— a pallasite. . . 225

Plate XLI. View of a mass of the Disco native iron 236

Corrigenda.

Page 39, seventh line, for "eruptions" read eruptives.

Page 39, tenth line, for "this" read thin.

Page 71, fifth line from the bottom, for "microscopic" read macroscopic.

Page 76, tenth line from the bottom, for "deposition'' read disposition.

Page 77, second line from the bottom, for "microscopic" read macroscopic.

Page 78, seventeenth line, for "scabs" read scales.

Page 106, fifth line from the bottom, for "distributed" read disturbed.

Page 209, thirty-first line, insert .45 in the blank space at the right.

Preface.

This bulletin is the direct outgrowth of a law passed by the Minnesota Legislature in 1887 requiring the state geologist to make special examinations for the discovery of any economic product, which he might hava reason to believe existed at any place in the rocks of the state, and to report thereon for the information of the citizens of the state. Ten thousand dollars were appropriated for these special researches and tests. There was first an effort made to find natural gas, and the report thereon is published in bulletin No. 5. Attention was then directed to the northern part of the state with a view to make such drilling- tests as would throw light on the extension of the Mesabi range through the region between Mesabi station and Pokegama falls on the Mississippi river. It became at once apparent that the entire sum of money appropri- ated would not pay the cost of any such special, thorough, and practical testing for iron ore as the law contemplated, and that therefore it would be necessary, in order that the law and the ap- propriation be not defeated in their purpose wholly, to make a more general survey and report on the iron ores of the state. This examination was expanded rapidly into a very important and far- reaching investigation, and the report herewith, while employing all the data that had already been gathered by the survey directed solely to this object, is based very largely on new facts and sur- veys made available through this special law. Therefore, while embodying one of the results contemplated by the general law of the survey, it appears now as a diversion from the regular course of the work of the survey, and should not be considered as its final statement on the iron ores of the state.

We have attempted to give, in this bulletin, such information concerning the iron ores of MinDesota as might be wanted by the explorer, the miner, the geologist and the citizen of the state. There has been a great demand recently for such a discussion of the iron ores of the Northwest. As the discovery of new mining grounds has, year after year, extended the interest in iron mining among a greater number of individuals and corporations who nat- urally look to the official survey for information and guidance, so have the number and complexity of the problems involved in- creased. We have not essayed the settlement of all the scientific

Vill PREFACE.

questions that have arisen through this extension of the field of observation. We have simply collected the new facts as we have learned them and have made an initial effort to group all of them, both old and new, under a classification intended to make them in- dicate some general principles. Our results are not wholly in ac- cord with those of some of our predecessors — as theirs were not with theirs. We would have been glad to have taken more time for further field and laboratory work. It is evident, however, that we should never reach perfection. It was equally evident that justice to a large and expectant constituency required the prepara- tion of a report on the iron ores, however far it might fall short of rendering justice to the subject. It is only through successive partial studies, and the publication of the incompleted results that some additions are made to our knowledge of the geology of the ores of iron. Our contribution to that fund of knowledge will go with others, both earlier and later, to enable some fortunate future geologist to prepare an exposition that will be both thorough and complete. We shall be satisfied if we may be able to add a small quantum to that end.

We may, however, mention those parts of this report which we consider as presenting features that embody original views, or new combinations of well known facts, or that will be found to be of particular value to the geologist or the practical mining man.

1. The separation of the ores of the Northwest into two geolog- ical formations, and those of Minnesota into four formations, and the special description of each. This has never before been done except by us in some of our preliminary papers.

2. The differentiation, and yet the genetic derivation, of the crystalline schists and their ores from the greenish, fissile schists of the Keewatin and their ores.

3. The demonstration of the chemical precipitation, in Keewa- tin time, of the chalcedonic silica of the jaspilyte, in the bottom of the Keewatin ocean.

4. The deep-sea origin; as a chemical precipitate, of the asso- ciated hematite of the mines of the Vermilion range, and to a large extent of those of the Mesabi range.

5. The primordial, i. e., Taconic, age of the ores of the Mesabi range.

6. The primordial, i. e., Taconic, age of the gabbro of the Mesabi range, and hence of the associated granites and the con. tained titanic magnetites.

7. The theory which is maintained for the origin of the iron ores of Keewatin age contains some new elements, and is essentially

PREFACE. iX

a new theory. Bat we advance it confidently, believing that the evidence abundantly justifies the conclusions.

8. The bibliography of the origin of iron ores is something which we have not seen elsewhere, and which we believe future students will find particularly useful.

9. The lists of mining corporations and land leases for mining, and the glossary of mining and geological terms, will be found useful and convenient by all mine operators and interested capital- ists— more especially those of Minnesota.

10. Although the general trend only of the geological forma- tions is shown on the accompanying map in the western part of the area included in it, still as a whole the map is an advance on all previous maps, and in the eastern part it is largely based on positive facts of observation.

We cheerfully acknowledge assistance that we have received in the preparation of this report. Everywhere we have been received by mining communities and by representatives of railroad and mining corporations with the utmost cordiality, and have been afforded every facility to make such examinations as we desired* We wish specially to thank the Minnesota Iron Company, the Chandler Iron Company, and the Duluth and Iron Range Bail- road Company. Personal favors, and special information have been afforded by Mr. George C. Stone, St Paul, Superintendent D. H. Bacon, Tower, T. B. Hoover, Duluth, G. C. Greenwood, Duluth, John Mallmann, Mesaba, H. A. Wilcox, C. T. Waters and Capt B. J. Williams, Tower, Superintendent Jos. Sellwood, Capt. John Pengilly, Capt. Henry Roberts, Capt. Philip Scadden and Superintendent McQuade, of Ely, Mr. Eli Griffin, Minneapolis, and Henry Mayhew, of Grand Marais. We have also to acknowl- edge favors from the American Diamond Bock -boring Company, Chicago, E, P. Allis and Company, Milwaukee, the Ingersoll-Ser- geant Bock-drill Company and the Band Drill Company, of New York.

N. H. WINCHELL and H. Y. WINCHELL.

Minneapolis, March 10, 1891.

The Iron Ores Of Minnesota.

Part I.

Their Geology And Distribution.

Introduction And General Considerations.

Recentness of the development of the Minnesota ores. The de- velopment of the iron ores of Minnesota is of recent date. It is so recent, and has been so rapid and so great that the importance of the industry has not yet come to be realized except by a few who are closely associated with it, or who are themselves interested in other iron districts and have consequently felt the impress it has produced on the iron industry, in general, of the whole country. Although iron ore was known to exist in considerable quantities in the northern part of the state since the official announcement of the same by the state geologist in 1865,* no practical mining of it was attempted till 1884. The shipments of ore from Two Harbors on the north shore of lake Superior, for the six seasons during which the mines have been worked is as follows:

Shipments for 1884f 62,124 tons

Shipments for 1886 225,484 tons

Shipments for 1886 307,948 tons

Shipments for 1887 894 910 tons

Shipments for 1888 511,968 tons

Shipments for 1889 844,638 tons

Total product of the six years 2,847,057 tons

This product, prior to 1888, was the output of a single company, from the Minnesota mine, at Tower; but in the years 1888 and 1889, the Chandler mine, at Ely, produced 56,712 tons and over 306,00J tons respectively, and in 1889, the Pioneer mine, also at Ely, shipped 3,100 tons. Of all iron districts in the country the lake Superior district is the most productive, and has shown the largest results from short exploitation; yet in the lake Superior region in its whole history no mine has produced in the third year of its operation as large a tonnage as the Chandler produced in its

*H. H. Eames, Report on the metalliferous region bordering on lake Superior, 1880, p. 11.

tShlpments of Iron ore are In long tons of 2240 pounds.

2 Bulletin No. Vi.

second year, and there are no two mines in the entire lake Superior

region whose combined product for any one year equals that of the

Minnesota and Chandler mines. For these six years there has

been a consecutive increase over the previous year's product as

follows:

Increase of 1885 over 1884 259 per cent.

Increase of 1886 over 1885 36 per cent.

Increase of 1887 over 1886 28 per cent.

Increase of 1888 over 1887 30 per cent.

Increase of 1889 over 1888 65 per cent.

The increase in the Marquette district during the same six

years was as follows:

Increase of 1885 less than 1884 8 per cent, (decrease)

Increase of 1886 over 1885 14 per cent.

Increase of 1887 over 1886. . , 14 per cent.

Increase of 1888 over 1887 3% per cent.

Increase of 1889 over 1888 26 per cent

The increase in the Menominee district (Wisconsin and Michigan) for the same years was as follows:

Increase of 1885 less than 1884 20 per cent, (decrease)

Increase of 1886 over 1885 26 per cent,

Increase of 1887 over 1886 34 per cent.

Increase of 1888 less than 1887 3 per cent, (decrease)

Increase of 1889 over 1888 43 per cent.

For the Gogebic range (Wisconsin and Michigan) the corres- ponding ratios are expressed as below:

Increase of 1885 over 1884 11,601 per cent

Increase of 1886 over 1885 541 per cent.

Increase of 1887 over 1886 70 per cent.

Increase of 1888 over 1837 11 per cent.

Increase of 1889 over 1888 23J per cent.

It appears, therefore, that during the four years prior to 1890 there was a loss in the average rate or increase in all the lake Su- perior districts, except the Vermilion district, and that in 1889 the rate of increase in the Vermilion district was more than double that of the same year for the Marquette and the Gogebic ranges and was more than one-third faster than that of the Menominee district*

The development of such an iron product in so short a time is an event of more than local significance, and demands the atten- tion of all who are interested in the iron industries of the country.

Changes and improvements. The iron ores of the Northwest,es- pecially known as those of the lake Superior district, were discov- ered by surveyors employed under the state geologist of Michigan,

Owing to delay in the printing of this report it is now possible (December 8, 1890), to add the aggregate shipment of the Minnesota mines in the season of- 1890. It amount- ed to 880,200 tons.

Iron Ores Of Minnesota. % 6

Douglass Houghton, in 1844 In 1846, a short account of the iron deposits near Negaunee was published by Jacob Houghton, Jr., and F. W. Bristol.* In 1851, two United States geologists, Messrs. Foster and Whitney, made the first systematic examination tod report on the geology of the iron ores of Michigan.f In 1873 was published the report of T. B. Brooks, as one of the state geologists of Michigan, on the iron-bearing rocks of that state, and a few years later that of Dr. C. Rominger, of the same survey, on the rocks of the same region.}! These valuable and reliable reports, it is needless to state, have served as authority on all the questions therein discussed, and have aided, in many ways, in the material no less than in the scientific development of the iron ores of the Northwest At still later date, though before the practical exploi- tation of the iron ores of the Gogebic district, the geology of the rocks of the Penokee-Gogebic range has been presented system- atically by the Wisconsin geological survey concluded by Prof. T. C. Chamberlin.||

As time has passed, since the publication of the report of major Brooks on the ores of Michigan, changes have taken place both in the mining methods and in the market demands, and discoveries have been made in the geological environments of the ore bodies. New competitive iron districts have been opened up and new cen-

Mineral region of lake Superior, by Jacob Houghton, Jr., and F. W. Bristol, 109 pp. and map. 1846, Detroit, contains reports by Burt, Hubbard, D. Houghton and Stan- nard.

+ Report on the geology of the lake Superior land district. Part n. The iron region, by J. W. Foster and J. D. Whitney, 1851. Much of the information given in this report was gathered under the direction of Dr. C. T. Jackson, who had charge of the survey from 1847 to 1840. His plans and his work seem to have been interrupted and disoarded without sufficient known cause, and the credit of the final report was transferred to other hands which perhaps were not wholly friendly to Dr. Jackson. Some evidence of this is found in that rara avis of American geological publications, Sen. Doc. M Sew. 3l9t Cong. 1843-50, III, pp. 371-935K Jackson directly refers to it in A. A. A S., 1849, Cam- bridge meeting, p. 283. The transfer to Foster and Whitney was owing to a change In the political control of the U. 8. government. There is also another edition of Dr. Jackson's reports and accompanying documents, having paging from 355 to 019. but this embraces, beginning at p. 780, 'Reports on the linear surveys, with reference to mines and minerals in the northern peninsula of Michigan in the year 1845 and 1846," being the report of Win. A. Burt and Bela Hubbard on the work under charge of Dr. Douglass Houghton, state geologist of Michigan for 1845, and Burt's geological report on the same, continued after Dr. Houghton's death, for 1846. See also "Memoir of Dr. Douglass Houghton/' by Alvah Bradlsh, Detroit, 1880, p. 205.

X Geological survey of Michigan, 1860-73, accompanied by an atlas of maps. Vol. 1, Part 1. Iron-bearing rocks, T. B. Brooks, 1873. Also Vol. 2, appendices to Vol* 1, Part 1, T. B. Brooks.

Geological survey of Michigan, Upper peninsula, 1878-1880, accompanied by a geol- ogical map, Vol. IV, C. Rominger, 1881.

I Geology of Wisconsin, In four volumes, 1873 to 1879, with large geological atlas. In sheets. The crystalline rocks are presented In various parts of all these volumes, the contributors being Profs. T. C. Ohamberlin and B. D. Irving. E. T. Sweet, C. E. Wright, A. A. Julien, Arthur Wlchmann, T. B. Brooks, B. Pumpelly, F. H. King and 0. B. Van Hlse

4 Bulletin No. Vi.

tres of iron-making, necessitating new routes of transportation, have been established. These facts alone wonld warrant a new discussion of the iron ores of the Northwest, bat when in addi- tion, one of the most remarkable iron districts has sprung up within the limits of Minnesota, where, less than ten years ago, the country was in its primeval condition undisturbed except by the feeble energies of the aborigines, it is a duty incumbent on the existing geological survey to make known thoroughly all the facts that pertain to the history and geology and improved methods of this industry.

Sketch of what the earlier Minnesota reports have said. It has been one of the objects of the survey, in the prosecution of the study of the crystalline rocks, to furnish from year to year, what- ever information there was that was reliable, relating to the prog- ress of the iron industry in the state. In the seventh, ninth, tenth, eleventh, thirteenth, fifteenth, sixteenth, seventeenth and eighteenth annual reports such fragmentary information is presented.

In the seventh report (for 1878) is given a short account of the Mesabi iron range, the rocks of which are stated to be the down- ward graduation of those that furnish the silver ores at Thunder bay. Two chemical analyses are given, showing the usual char- acteristics of those ores. The ore here included is mainly in the form of magnetic oxide, from towns 59 and 60, range 14, and is shown to be a non-titanic Bessemer ore.

The ninth report gives some details of field-observations at the same place at which the samples were obtained, which were analyzed (as above) for the seventh report (pp. 107-109). This report also contains a sketch and map of the Prairie Biver falls, where the same kind of ore is found, being, indeed, in the west- ward extension of the same strata. (Compare pp. 196-198).

The tenth report gives no special facts relating to the iron ores, but calls attention (pp. 7-8) to some general considerations touch- ing the prospective importance of this industry to the state of Minnesota, in the following words:

"The report of the survey for 1878 called attention to the existence of iron ore in the northern part of the state in large quantities, and to the fact that parties interested in iron from eastern states have made costly surveys and examinations, attesting the value of these deposits by field-exploration and by laboratory assay. Since then others have become interested in the same way, and it is not premature to predict that the iron ores of Minnesota will, not many years hence, be largely wrought, and yield to the state a revenue which will be commensurate with the extent of the deposits and the importance of such industry. It would be well if the capitalists of Minnesota would look after this matter, and by concerted action retain within the state as much as

Iron Ores Of Minnesota. 5

possible of the profits of such development of these ores. The blast furnace which is now in operation at Duluth, using ores from Marquette, should be supplied from Minnesota, and Minnesota railroad companies should see to it that these ores are made accessible. Our iron ores are the furthest west of all the lake Superior deposits, and, being in the midst of timbered lands, are situated favorably for reduction by charcoal; while the great region west and northwest, destitute of the rocks producing these ores, will always have to de- pend on us for iron and its products in the same manner as for lumber. East- ern iron deposits, and eastern furnaces, should not be allowed to find it profit- able to send their products past our doors when we have every requisite and every facility for producing the same. It would be a thing highly creditable to the regents, and to the university, to be directly instrumental in develop- ing this great industry, and I hope that general attention may be called to its feasibility.

The eleventh report (for 1882) contains Prof. A. H. Chester's paper on the Minnesota iron districts, and a note by the writer on the age of the rocks of the Mesabi and Vermilion iron districts. The former announces the results of field and laboratory researches that were made for the Minnesota Iron Company prior to their entering upon the systematic and extensive exploitation of the ores of the state which has marked the past few years, and will always be considered as the initial and most important step in their de- velopment.

In the thirteenth report is a succinct account of the results of the first year's mining by the Minnesota Iron Company, with a description of the various openings made near Vermilion lake, em- bracing numerous chemical analyses of the ore.

The fifteenth report is taken up very largely with the geology of the iron bearing rocks, giving the detailed field-observations made in the season of 1886, with a colored geological map of the region, extending from Vermilion lake to Pigeon point. It also has a more detailed map of the region of Vermilion lake.

The sixteenth report is similar to the fifteenth, but its scope is less restricted. It has a geological map of that part of the state between the Rainy river and the headwaters of the Mississippi, and embraces comparative observations on the original Huronian, north of lake Huron, and on the iron-bearing rocks at Marquette, Negaunee and on the Gogebic iron range in Michigan, as well as the Penokee region in Wisconsin.

The seventeenth report consists of further detailed field-obser- vations made along the iron ranges of northern Minnesota, and a summarized review of the work of the survey on the crystalline rocks of the state, giving some idea of the resultant classification and probable stratification.

The eighteenth report embraces the field-observations of N. H.

6 Bulletin No. Vi.

Winchell in 1888 and 1889. These were made in the iron regions east from Pokegama falls, on the west end of the Mesabi range, and in the region about Tower and Ely. It also embraces some notes made on the crystalline rocks, in the Minnesota valley, and in the region of the typical Huronian. The studies in the field, in L889, were calculated to supplement the field-notes of former sea- sons, and were made, in many cases, on the same rocks at the same points, with a view to arrive at the solution of some of the prob- lems that had arisen, and particularly as to the origin of the jas- pilyte and iron ore. Some of the facts on which the conclusions of this bulletin are based are there given in more detail and with illustrations of the fieJd relations more full than in the bulletin itself.

Another portion of the eighteenth report presents a conspectus of the progress of opinion among American geologist on the origins and classifications of the crystalline rocks, from the earliest obser- vations to the present time, by Alexander Winchell.

Accompanying these field observations, and enumerated in the corresponding pages of the several reports, numerous rock-samples were collected. So far as any descriptions of rocks, ores or miner- als are given in this bulletin the same numbers for designating them are employed as in the annual reports, and the reader is re- ferred to these reports for more details of the field relations. A list of all the rock-samples referred to in this bulletin, and the lo- calities where they were obtained, will be found in Appendix D. p. 420.

(1.) The Magnetites Of The Vermilion Schists.

The existence of merchantable iron ore in the crystalline schists within the limits of Minnesota, was definitely ascertained in the season of 1889, when opportunity was afforded of visiting an ore deposit north of Long lake. This ore had been reported to exist in that neighborhood two years before, and one of the parties of the survey had made search for it, but being without guide ac- quainted with the region, it failed to find the ore, and its existence was considered one of the many ill-considered rumors that are constantly being started and repeated concerning the discovery of iron ore. The location is lots 4 and 5, sec. 4, and lots 4 and 5,

Iron Ores Of Minnesota. 7

sec. 5, 63-12, and it was through the aid of Mr. John Mallmann and Mr. E. C. Hillbery that samples of the ore were procured. The country rock is represented by 417 (H) and 418 (H).

By reference to the sixteenth report, page 112, it may be seen that a magnetic ore at the north end of White Iron lake was re- ferred to the Vermilion age in 1887, that then being pronounced "the only known iron ore locality in the rocks of that age." The ore here has not been regarded of sufficient value to work, but there was formerly some cutting into the perpendicular quartzose schists for silver, from which the place was known as Silver City. More important discoveries of valuable deposits of iron ore near this place have been reported since.

(a.) Nature of the Enclosing Rocks.

(1). Macroscopic. — These magnetites are embraced in the mica- hornblende schists, or crystalline schists, which constitute the form- ation lying next above the granite or gneiss of the Lauren tian. The rocks contained in this series are various, in some respects, yet they sustain a constancy in lithological ensemble which distin- guishes them, in nearly all places, from the next overlying (Kee- watin) series. Their prevailing colors are dark, sometimes nearly black, shading to dark green when they become massive. Only in limited areas and much weathered, or decayed, conditions does this dark green fade into a lighter green. In connection with the minerals that give these dark colors, (mica, hornblende, magnetite) will be found, in nearly all cases, a percentage of free quartz. When this is abundant enough to make itself seen in distinct lay- ers or deposits, it is very fine grained, resembling the granular jas- pilyte of the Keewatin rocks, but on account of the exceeding fineness of both the quartz and the mica, and because generally the quartz is not in distinct and isolated layers or deposits, very much of the rock embracing this ore becomes a magnetitic and micaceo-hornblendic dark quartz schist, shading from light gray to purple and black as the proportions of the minerals vary. Much of it is not magnetic appreciably. A very evident sedimentary structure is thus brought out, the quartzose lamina) being from an inch or a quarter of an inch thick to less than a thirty- second part of an inch, and in some cases almost disappearing because of the uniform dissemination of the darker minerals. This phase is represented by the schists at the north end of White Iron lake.

There is, however, another phase of this iron bearing rock. It is dark-colored, but greenish, massive and more coarsely crystalline. The magnetite crystals are abundantly scattered through the rock,

8 Bulletin No. Vi.

increasing in such a degree that the rock becomes the ore. Yet in the purest parts of the ore may be seen hornblendic and micaceous masses, giving a greenish, sometimes a mottled aspect. The rock is hard and the surface is hilly and not at all attractive to the ex- plorer. This latter condition exemplifies the supposed igneous characters of the Vermilion series, but these are found sometimes to gradually fade out and a sedimentary lamination to supervene. Sometimes, however, this massive condition is seen to be abruptly replaced, unconformably, by distinctly quartzose and micaceous schists. Cinnamon garnet frequently accompanies both the schists and the massive rock in the neighborhood of such transitions. This massive rock seldom contains quartz in noticeable amount and indeed in nearly all cases it appears to be wanting, unless it be of subsequent (secondary) deposition.

Bocks 950, 951 and 1446, illustrate these schists at the north end of White Iron lake.* Hocks 417 (H) and 418 (H) are from this dark and massive phase north of Long lake.

(2) Microscopic. We have had the assistance of Dr. H. Hen- soldt, of the Columbia College School of Mines, in the prepara- tion of the descriptions of the microscopic characters. The slides were made in the survey laboratory either by us or by Mr. O. W. Oestlund, and the illustrations seen on the microscopic plates have been prepared by us. They are such as will illustrate the descrip- tions. The numbers attached to the specimens in the field are the same as those employed in these pages. The microscopic characters of the Vermilion schists are illustrated on plate v, figs 1, 2 end 3, which are drawings from Nos. 417 (H), 418 (H) and 1446 respect- ively.

Bock 417 (H). This rock (see plate v, fig 1) is essentially com- posed of hornblende and labradorite and must, therefore, be classed among the diorytes. In its microscopical structure it closely re- sembles some of the intrusive coarse-grained diorytes of Essex county, Massachusetts, examined by the writer for the Peabody Academy of Science at Salem, in 1888. In its unweathered condi- tion the rock is dark- gray, with a tinge of green ; weathered sur- faces appear as if daubed with innumerable specks of a whitish paint, these latter having resulted from a complete kaolinization of the labradorite crystals. Hornblende and labradorite are present in about equal proportions. The hornblende scales are full of the

Dr. M. E. Wadsworth's specimens from this locality, so far as they Illustrate the schist, are numbered 1111-1115, 1122-25, 1127. Those of A. Wlnchell are numbered 100- 103 and 080-987. Of the collections of H. V. Wlnchell, No. 543 ( H) Is a sample of the ore from the north side of Long lake, and Nos. 417 (II) and 418 (II) Illustrate the country rock north of Long lake.

Iron Ores Of Minnesota. 9

usual cracks and fissures, and are but slightly affected by decom- position along the marginal portions, where minute fibres are observable, indicating a transition into chlorite or epidote. In color the hornblende presents three shades of green, according to whether a scale is cut parallel, or nearly so, to an axis of greatest, medium or least elasticity* and the scales are remarkably f reef rom enclosures. If tested with the lower Nicol (polarizer) only an in- tense pleochroibm is noticed. The labradorite occurs in the shape of crystals and granular masses, which were doubtless originally colorless and transparent, but which are now more or less turbid and clouded by kaolinization. Some pellucid crystals are still to be noticed, and these show between crossed Nicol s the character- istic twin-striation. A faint twin- lamellat ion is also manifested by many of the clouded crystals, which have not yet been completely metamorphosed by kaolinization. A few brownish scales, free from cracks and bounded by parallel lines, indicate the presence of biotite as a minor accessory. They can be easily distinguished from the hornblende by their form, color and pleochroism, which is even more intense than that of the amphibole. Small grains of magnetite are sparingly distributed over the field; they are in many instances surrounded by a brownish decomposition zone.

R:>ck 418 (H), (see plate v. fig. 2). A rock of practically the same composition as the foregoing (No. 417 S), from which it differs only structurally. It is however more compact and fine-grained, and shows an almost schistose arrangement of the hornblende and feld- spar constituents, so that it might, not incorrectly, be termed a hornblende- schist. The hornblende is darker, and even more pleochroic, than is 417 (H); it contains numerous roundish enclo- sures of a colorless, isotropic substance, possibly a kind of glass. (Glass enclosures are of common occurrence in the hornblende of nearly all crystalline schists.) Such of the labradorite crystals as are not completely kaolinized, show twin-striation, and in many instances the smaller grains have been replaced by secondary quartz. Not a trace of quartz could be observed in 417(H) and from this circumstance, as well as the complete absence of biotite in our present rock, the writer would conclude that 418(H) either represents a more ancient type of the same dioryte or that the modifications which it presents are referable to local differences in the conditions which prevailed during the ages of metamorphism, such as heat- pressure or the effects of contact with contiguous rock-masses

'Sections parallel to a are of a light yellowish green color. Sections parallel to tr show a brownish green tint, while those which approximate to c are uniformly dark- green, almost bluish.

10 Bulletin No. Vi.

This rock, which partakes more of the character of a hornblende- schist, affords an instructive example of the manner in which an "orthodox" dioryte may be transformed into a schistose rock by changes comparatively slight, and if we can follow a rock till it assumes a still more schistose, dense or comminuted character till it passes into a regular slate, many of our present petrographical terms and conceptions will require overhauling.

Book 1446. A greenish-gray, compact rock (see plate v. fig. 3) exceedingly hard and dense, like basanyte, which shows an almost vitreous fracture and which, judging from its megascopical aspect alone, one might well call an aphanitic quartzyte.

The microscope, however, shows it to be composed of innumer- able layers of silica originally deposited in an amorphous condition, in the manner described in No. 867 (see Jaspilyte) but now simu- lating hexagonal quartz crystals. These layers are closely inter- bedded with minute, elongated greenish scales, of a mineral which was, doubtless, once hornblende, but which has been completely transformed into fibrous epidote. It is this mineral which causes the greenish appearance of the rock, as without it the latter would merely present a uniform tint of gray. In addition to the layers of silica and epidote the rock contains a considerable quantity of magnetite, which is distributed in the shape of opaque grains and crystals, showing cubical and trigonal faces. Some of the magnetite layers consist of much coarser crystals than the others and the silica interposed between these crystals is remarkably clear and polarizes in lively tints, yet the joined globules or hexagons usually show several colors, with a marginal zone, and are totally devoid of fluid-cavities, which clearly indicates their chemical origin. The epidote scales are very evenly distributed and although some of them are much larger than others, yet, on the whole, they are characterized by considerable uniformity in size, shape and color. A "half-inch" objective shows each scale to be a mere aggregate of fibres, like a bunch of straw, and this may be still better observed in sections cut parallel to the plane of stratification.

(3). Structural features. — Structurally this ore in its first phase above bears a close resemblance, in its relations to the enclosing rock, to the hematites of the Keewatin series. Its lamination with thin siliceous bands, and its giving place, in various degrees of diminution, to more or less siliceous, parallel, generally contorted sheets, some of which approach pure silica, is quite identical with the behavior of the hematites that accompany the jaspilyte of the Keewatin. This structure is exemplified by the deposit at the

Iron Obes Of Minnesota. 11

rapids from White Iron lake to Garden lake. The perpendicular attitude of the beds is also like that of the Keewatin lodes.

There is, however, so far as known, no Keewatin counterpart for the structural features that are exhibited by the Vermilion mag- nitites seen north of Long lake. Here the ore is apparently a pri- mary constituent of a massive rock, the associated minerals and the non-titaniferous character of the ore alone showing its alliance with the Vermilion rocks, rather than with the magnetitic gabbro of the Mesabi range. The structure here has not been f ally ex- amined by the survey, and the foregoing statement is based on a general knowledge of the country rock in the region, and on sam- ples that have been furnished by Mr. Mallmann. There may be here also a bedded structure that would appear on making a full examination. But taking the facts so far as they are known it may be said that, north of Long lake, this ore is apparently em- braced in a massive eruptive rock in somewhat similar manner as the titanif erous ore is embraced in the gabbro.

(b.) Qualities of the Vermilion Magnetites.

(1). Chemical, etc. This ore was analyzed by Prof J. A. Dodge, of the University of Minnesota, the specimen being one ob- tained from Mr. Mallmann — No. 543 (H) — with the following result:

Analysis Of The Vebmilion Magnetites.

Silica, Siof 10.90

Alumina, Alt O, 5.83

Sesquioxide of iron, Fet O, 70.39

Protoxide of iron, Fe O 8.75

Lime, Ca O 1.20

Magnesia, Mg O 1.50

Sulphur, S 47

Phosphorus, P 022

Manganese, Mn none

Titanium none

Metallic iron 56.08

This shows a Bessemer ore, though not one of very high rank in metallic iron. The absence of titanium indicates that the rock, at least the ore here analyzed, is not in an original eruptive state, but that the ocean had acted on the sediments, whether of eruptive origin or not, sufficiently long to decompose and extract it (if ever present) prior to the present crystalline condition of the rocks.

(2). Origin of the Vermilion magnetites. It seems to be nec- essary to consider these ores as having at least two different methods of deposition or origination. This inquiry goes no f urth-

12 Bulletin No. Vi.

er back than to include their condition immediately before their taking that which they now have; for it is evident that iron can be traced through many changes, mechanical and chemical, due to the vicissitudes of geological history, and that each change might be considered the resultant of forces that preceded, and also the participating cause of those that followed. The ultimate ter- restrial source for all superficial iron deposits, whether native or in the form of chemical compounds, may be accepted, for our present purposes, to have been the central molten portions of the globe, according to prevalent accepted deductions* from physical and mathematical laws, and from the more recent observations of Nor- denskjold on the iron-sheeted basalts of Disco island. Appearing as metallic iron, it has gone through such transformations as its chemical and physical environments have made necessary. Some- times it has maintained the condition it assumed early in its his- tory, and at other times it has been subjected to numerous trans- formations and chemical combinations. The ores that are found in the later strata of the earth's crust have a more complicated his- tory, and more diverse origins, than those contained in the Archean rocks.

The Vermilion ores f are believed to be the result of hydro- thermal forces, acting at considerable depths within the earth's crust, on sediments and on eruptive rocks, and on iron ores that were at first nearly or exactly like the rocks and ores of the Keewatin series, which next succeeds the Vermilion series. It will be prop- er, therefore, to consider the methods of their earlier deposition as Keewatin constituents, at a later stage in the progress of this report, and to discuss here, briefly, only the manner and cause of their having their present condition. It will not even be neces- sary to enter on the geological evidence that these ores were form- erly in the condition of Keewatin ores. We shall assume that, at present, and shall only call attention to the manner in which they have probably been converted to magnetites, and the enclos- ing schists to crystalline schists.

In order that there may take place in a rock-mass of any mineral composition, a slow metasomatic change converting it into a dif- ferent mineral composition, there must be some predisposing causes acting on a favorable conjunction of mineral conditions, and those causes must be brought into activity and maintained

See Volcanoes, J. W.Judd. pp. 318-322. The theory aeems to have originated with Sir Humphrey Davy. See "Iron Manufacturer's Guide." Lesley, p. 357. Principles of Geology; Lyell. Vol. 11, p. 229. (11th Ed. 1872), Phil. Trans. 1828, 244.

+ The term Vermilion here, applies to the Vermilion series not to the "Vermilion iron range."

Iron Ores Of Minnesota. 13

daring long periods of time. This problem is resolved, therefore, into an inquiry for these causes and conditions.

The general characteristic nature of the rocks of the Keewatin series has been stated by Dr. Geo. M. Dawson, Dr. Andrew C. Lawson, f and by the writers.}; But the actual petrographic characters have been more carefully investigated and published in the late report of Dr. Lawson on the region of Rainy lake. In general it is agreed by nearly all who have examined them, whether in the field or in the laboratory, that they are characteristically composed largely of materials that had, at first, an eruptive origin, although they exhibit very generally a stratiform arrangement that can be attributed only to the action of oceanic sedimentation. They vary from very evidently eruptive, almost non-quartziferous, basic materials to very siliceous schists. But in all cases they contain a common element, a chlorito-sericitic paste. This paste or typical character sometimes appears much like talc, and in otitis apparently serpentinousfbut the general term sericitic, or hydro- micaceous, is usually applicable. The individual, characteristic minerals that are embraced in tHe Keewatin rocks, so far as it is necessary to consider them in this inquiry, may be reduced to four, viz: 1. A chloritic mineral. 2. A sericitic min- eral. 3. A feldspathic mineral (generally plagioclastic.) 4. Quartz.

These make up, in their varied proportions, in their various states of alteration, and in their varied structural positions, the great bulk of the Keewatin stratiform rocks. The non-stratiform consist of such as are easily reducible to these by the action of oceanic levigation and distribution. That is, in the massive green- stones of the Keewatin are found prominently augite and horn- blende, in addition to the foregoing. The iron ores, whether magnetic or hematitic (generally the latter) constitute, in limited areas, an important constituent, but they will be considered under a separate head. The various secondary minerals, calcite, epidote, limonite, pyrite, vitreous quartz, siderite, need not be embraced in an enumeration of the principal rock-forming minerals of the Keewatin.

Geology and Resources of the region of the vicinity of the forty-ninth parallel; 1875, p. 52.

tReport on the geology of the Lake of the Woods region, with special reference to the Keewatin (Huronian?) belt of the Archean rocks. Geol. Nat. Hist. Sur. Can. Vol. 1. New Series. 1885. Report C C.

Minnesota survey report for 188G, pp 220-222; ditto for 1888, pp. 38, 132; Am. Geologist, Vol. ill. p. 18.

I Report on the geology of the Rainy lake region. Geol. Sur. Can. Rep. for 1887. F. pp. 57-01). It should bo noted, however, that Dr. Lawson Includes under the term Keewatin most of the crystalline schists which in this report are styled Vermilion schists. His "Goutchiching series" is also apparently the same as the mica-schists of the Vermilion.

14 Bulletin No. Vi.

These minerals, it will be seen, would naturally constitute a rather easily disintegrated rock, and also one through which the metamorphosing forces would be quick to send their agents of metasomatic change. Sometimes felsyte has been mentioned in the field-descriptions, but this is an unhappy, even incorrect use of the term. The rock that has been so designated has been, in nearly all cases, a light- greenish, aphanitic, coarsely schistose, scarcely quartzif erous rock that is rather soft and intimately re- lated to the sericitic and serpentinous portions. It seems to be about what has been named porodyte by M. E. Wadsworth.* The firmest rocks that appear in the Keewatin are crystalline granitoid masses, also porphyries, which are of isolated and rare occurrence, apparently the result of fusion and intrusive flowage from some of the strata of the Keewatin itself. The greenstones are inter- mediate, in hardness and endurance, between the porphyritic and and granitoid bosses, and the sericitic schists.

The general characteristic nature of the rocks of the Vermilion series is also well known, and has been stated by different obser- vers. The rocks are essentially micaceous and hornblendic schists, generally showing a sedimentary stratiform arrangement. They also pass into massive greenstones whose composition and manner of occurrence have not been observed to differ from the composi- tion and manner of occurrence of the greenstones of the Keewatin. They are firmer, as a class, than the schists of the Keewatin. They are invaded by granitoid masses of larger area, of more frequent occurrence and of more crystalline character. They change in other places to gneiss gradually in their lower portions, and to the sericitic and chloritic schists of the Keewatin gradually in their upper portions, Sometimes also along their strike, the siliceous element increases or fades out.

The individual minerals that make up the bulk of the Ver- milion series, irrespective of the smaller variations and of secondary products, may be put under four heads, viz.: 1. A hornblendic mineral. 2. A micaceous mineral. 3. A feldspathic mineral, (frequently orthoclastic) and 4 Quartz. There are augitic con- stituents, also olivinitic, in the massive greenstone areas, but they are reducible either to hornblendic or micaceous, and do not play any independent role as minerals and may be disregarded in this comparison. These minerals are so distributed through the Vermilion that the rocks they compose are sometimes dark colored and basic, and sometimes exceedingly siliceous.

The iron ores that are found in the Vermilion, in Minnesota, are

♦Bull. Mus. Oomp. Zool., V. 280; VII. 60.

Iron Ores Of Minnesota. 15

magnetic in all known instances. They are sometimes in the schists and sometimes apparently in the massive greenstones. If the Keewatin petrographic characters, as above enumerated, now be compared with the Vermilion, after cancelling like elements, there will be found remaining these differences.

On the part of the Keewatin. On the part of the Vermilion.

A chloritic mineral. A hornblendic mineral.

A sericitic mineral. A micaceous mineral.

A feldspathic mineral (gener- A feldspathic mineral (frequent- ally plagioclastic.) ly orthoclastic. )

Hematite iron ore. Magnetite iron ore.

The exact mineral differences. It will be necessary next to ex- amine more closely into these differences, in order to ascertain whether, as supposed, the above different characters as exemplified in the Keewatin are convertible, under the action of any powerful, known, long -continued metamorphosing cause, into those charac- ters that distinguish the Vermilion. It will be found, when the origination of the Keewatin sediments is considered, that the chlo- ritic and sericitic characters are supposed to have been derived from the action of hot, alkaline oceanic waters on the minerals that constituted the lavas and other ejecta from the Keewatin vol- canic vents. We have no better evidence of what those minerals were than what we may infer from an examination of volcanic mat- ter of later ages, and even of the present time. The basic dolerytes which may be supposed to be derived from the deeper portions, probably from below the crust of the earth, consist essentially of augite (a form of pyroxene closely related to hornblende), biotite, or black mica, plagioclase and magnetite. An occasional small amount of free quartz need not be considered. The minerals of this group are closely allied to those that distinguish, above, the Vermilion rocks from the Keewatin. In other words, the supposed change in the Keewatin minerals, which is to be effected to con- vert their distinctive characters into those of the Vermilion dis- tinctive minerals, is one that is to bring them into closer resem- blance to those from which they are at first supposed to have been derived.

Tlie conversion of the Keewatin chloritic mineral into the Ver- milion hornblendic. Is it a possible and natural process to change chlorite to hornblende?

The reverse, or the conversion of hornblende to chlorite, is a well-known and wide- spread change which the microscopic litholog- ist frequently encounters. It is one of the changes to which erup-

16 Bulletin No. Vl

tive basic rocks are specially liable, and the most common cause of their prevailing greenish color.

Chlorite is a compound of magnesia, iron, alumina, water and silica, the magnesia averaging about 34 per cent, and the water over twelve.* It is decomposed by hydrochloric acid, forming a jelly, and is completely soluble in hot sulphuric acid.

Hornblende differs from this in having about 12 per cent, of lime and no water. There are varieties of hornblende that contain some soda, or potash, or manganese, but they bear an insignificant ratio to the great mass of hornblende. The metamorphosing force, therefore, which may convert chlorite to hornblende must be such that it can supply this percentage of lime and remove about the same amount of water. Along with this process the molecular and crystalline structure must be converted from a monoclinic crystal- lization to a supposed hexagonal one.f

It is perhaps impossible, in the present condition of knowledge respecting the reconversion of secondary minerals back to their originals, to show unqualifiedly the actual steps and the certainty of the change here suggested from chlorite to hornblende. To show that it is possible, and that under conditions that may be plausibly supposed to have obtained, it is probable, is as far as we may be able to go. This change has been suggested by Dr. Law- son (Report on Kainy lake, p. 80,) in the following statement: "The darker, harder, more compact, often glistening hornblende schists appear to be in part an altered phase of the fissile green schists."

It will be noticed, again, that the change from chlorite to horn- blende, consisting in the acquirement of lime and the expulsion of water, brings about such an approach toward the composition of originally eruptive augite, that it illustrates the nature of the gen- eral alteration that has been alluded to, and suggests the applica- tion of heat acting in conjunction with water, during a long period of time, at greater or less depths within the earth's crust

It is necessary to find some reason for the loss of water and the supply of lime, and perhaps also a small amount of magnesia, to the hornblende, for in that interchange between lime and water consists the essential difference between the chloritic element of the Eeewatin schists and the hornblendic element of the Vermilion schists.

At this point it is interesting to note that a frequent secondary

♦The study of rocks. Rutley, p. 136.

t Authorities differ as to the crystalline system of chlorite. Apparently some varie- ties are monoclinic and some hexagonal.

Ibon Ores Of Minnesota. 17

mineral in the Keewatin schists, which has not yet been mentioned, is calcite; occasionally it is dolomitic. It appears not only as dis- seminated, often microscopic, grains among the sericitic and chloritic scales, causing a slight effervescence in hydrochloric acid, and as amygdules in some of the vesicular greenstones*, but some- times considerable masses of so-called limestone, or marble, are met with. These constitute lenticular masses of considerable di- mensions.! The existence of this lime, at least in the form of disseminated grains, has been assigned correctly to the degrada- tional change in the original crystalline rocks which is here in- ferred, and is thus spoken of by Dr. J. P. Kimball: J "The pres- ence of carbonate of lime in many of the schistose rocks of this region must be regarded as generally due to the decomposition of silicate of lime in the silicates of the primary crystalline sediment*, whence they were derived." We have here the needed element It is intimately present in the schists. It is necessary yet to find a force that can drive off the water and carbonic acid, and allow, or com- pel the union of the lime with the silicate from which it came.

It has already been intimated that this force was heat encroach- ing slowly, and through long periods acting on these fissile schists. But before considering its source and its cause, it may be best to inquire whether the other differences that have been noted be- tween the Keewatin and the Vermilion schists may be reduced to the same elements.

The conversion of the Keewatin sericitic mineral to the Ver- milion micaceous mineral. The sericites of the Keewatin are its characteristic minerals. They have given the name sericitic schists to these rocks in all of the Minnesota reports. This prevailing, omnipresent element has been designated "Keewatin stuff," and it pervades those parts that are fissile and those that are firm. It is equally characteristic in Michigan and Wisconsin as well as in Canada. It may be divided, on chemical distinctions, into various mineral species, but their general resemblance, both in composition and in crystalline structure, as well as physical and geological associations, warrants us in considering them as a whole under one term. Sericite, damourite, paragonite, talc, serpentine, all of which may be paramorphic products of change from muscovite and biotite, or sometimes from hornblende and olivine, are here included. They are hydrated, very fine fihro-laminate-grained, and have a

♦Seventeenth Minnesota report, p. 06; Fifteenth report, p. 05.

♦Tenth report, p. 01, (Rook Nos. 7-43 and 746); Eleventh report, p. 16ft; Fifteenth report, pp. 337, 371, 04-05; Sixteenth report, pp. 05, 317. *The Iron ores of Marquette, Am. Jour. Sol. May, 1865. Vol. wxi.x. p. 303. I A. Wlncbell. Minnesota sixteenth report, pp. 310, 312, 343.

-a

18 Bulletin No. Vi.

larger percentage of magnesia (when not replaced by iron, alumina or soda) and a smaller percentage of potash, than muscovite and biotite. The scales are light-colored, flexible bat hardly elastic.

The micaceous fnineral that prevails in the Vermilion series of schists is biotite, bat muscovite largely replaces it in many situa- tions, particularly in the typical mica schists, while toward the top it is apparently replaced by some of the hydro-micas, or those that characterize the Keewatin schists.* That is, there is a somewhat gradual transition, stratigraphical and mineralogical, from the typical Keewatin schists to the typical Vermilion schists, and none of the contained minerals evince this more completely than the micas. In the Rainy lake region the same transition takes place, according to Dr. Lawson, between his underlying Coutchiching mica schists and the overlying Keewatin. "For the most part the contact of the two series is one of apparent conformity, and there is even a sort of transition from one to the other, observable in many places, where fissile, green, hornblendic and chloritic schists are interbedded with more siliceous and micaceous ones."f

This is the case in every place at which this interval has been observed in northeastern Minnesota. Conglomerates and agglom- erates occur at various places, and apparently on different hori- zons in the Keewatin, as they do also in the Vermilion.

Throughout the typical mica schists of the Vermilion there is a larger amount of quartz than in the typical areas of the Keewatin, and it would be obviously impossible to convert by paramorphio change the constituents of one into those of the other, and preserve in the resultant rock a like proportion of free quartz. It is only in those cases when the Keewatin contains more than the normal amount of silica, that is, in most of the graywackes, that a typical mica schist could be supposed to be its metasomatic equivalent On the other hand there are basic portions of the Vermilion , situated near the bottom of the formation, which are as poor in free silica as any parts of the Keewatin, and have a hornblendic, even a massive dia- basic, aspect and composition. J The essential difference between the Vermilion and the Keewatin, touching the foliated mineral which they contain is, therefore, partly one of stratigraphic position in the series, and partly one of chemical composition. Obviously

♦Seventeenth Minnesota report, pp. 32, 37, 66.

tReport on the Geology of the Rainy lake region. Part F of the annual report for 1887, p. 38. Canadian Geological Survey. In some places Lawson has Inferred local un- conformity between the Keewatin and the Coutchiching— p. 105.

*8uoh have not been included in the Coutchiching by Lawson; indeed they arc not mentioned by him at all at the horizon of transition from the Laurontlan to the Cout- chiching. He finds such at the base of the Keewatin.

Iron Ores Of Minnesota. 19

there is do significance in the different stratigraphic order in which this mineral may prevail in the two formations.

The difference which it is necessary to explain on a plausible hypothesis is one that indicates, as with the chlorite and horn- blende, a force which will bring the hydro- mica element of the Keewatin back to, or toward, that condition which is near its origi- nal. Muscovite and its hydrated variations, are entirely secondary minerals, i. e., they are not found in primary basic eruptive rocks; biotite frequently occurs in such rocks. It is therefore a reason- able supposition that by the re-application of the same agents that gave origin to the primary conditions of these minerals, (i. e., heat, pressure and moisture) they would be restored to their origi- nal condition, or at least would show an approximation toward it The water they had taken up would be expelled and the potash they had lost by oceanic solution would be restored as soon as the water holding it in solution were reapplied with a sufficient de- gree of heat Therefore these differences are reducible to the same elements — namely, such that can be destroyed by the appli- cation of hydro-thermal action to the sericitic micas of the Kee- watin.

[Since the foregoing was written a very interesting discussion of the normal micas has been published by Alexander Johnstone, in the Transactions of the Edinburgh Geological Society, Vol. vi. part I, p. 17. We are gratified that the researches of Mr. Johnstone confirm, essentially, the course of argument em- ployed by us, and lead to such results that they establish not only the natural order of genesis of all the micas, but show that natural causes have produced them all from that which is found (biotite) in original condition in eruptive rooks. He says :

44 Seeing that all, or almost all, the micas of the recently formed igneous rooks are of the nature of biotite, which is therefore a product of igneous fu- sion, and that the micas of the older rooks are referable to the species biotite, hydrobiotite, musoovite and hydromuscovite, we may safely consider the first- named as the original mica, and all the others as being varieties generally de- rived from it The experiments which I have already quoted in the first portion of this paper show how the agencies of natural waters, etc., and time are all that is necessary to bring about the various changes in chemical and physical characters essential to the creation of those other varieties of mica. It is not, I think, needful to describe further the processes of evolution of the pale tinted species, as the experiments I have referred to and the following diagram show clearly enough the manner in which I believe the various changes must have taken place :

Bulletin No. Vi.

Diagram Of The Evolution Of The Micas.

Original ! Mica

— BjOTITE.

Which, by exposure to water, becomes

Hydkohiotitk.

Which, by prolonged ac

waters,

tion of the CO, injiatural becomes

in.

Hydromusco-

V1Te.

Which, by long-continued pressure

of its combined wa

and heat, loses nearly the whole ter and becomes

Muscovite.

Note.— The last, by exposure to natural water, can again become hydromuscovite, and then in the same way as III be reconverted into immcovlte; hydrobiotlte can also go back again into the condition of biotite."

Iron Ores Of Minnesota. 21

Can the feldspathio (plagioclas'ic) mineral of the Keewatin be converted to the feldspathic (orthoclastic) mineral of the Ver- milion? In other words can the alkaline base potassa or soda be substituted for the alkaline-earth bases of the plagioclase feld- spars? Although this distinction between the feldspathic constit- uents of the two formations is not a sharply marked one (both classes of feldspars being disseminated through them both) yet theoretically those of the graywacke would be expected to be pre- dominantly plagioclastic. This would result from their antece- dent origin as minerals of a basic volcanic ejection, and secondar- ily from the naturally more soluble character of the alkaline bases, by reason of which if potassa and soda were present they would be first extracted by the ocean. Now it is only in the typical quartzose mica schists that orthoclase is found in noticeable amount in the Vermilion series. In the hornblendic schists it is rare, and in the diabasic rocks at the bottom of the series it is ap- parently wanting, or exists as vein- material. The inquiry per- tains, therefore, to the possibility of converting some portion of the alkaline-earth feldspar grains in the gray wackes to alkaline feldspar grains of the mica schists. It will be noticed here that the needed change is identical with that which was last mentioned, viz., a substitution of potassa, an alkaline base, for lime or mag- nesia or some other alkaline-earth base. This difference, there- fore, so far as it exists between the two formations, is reducible to the same elements, and can be removed by the same cause, i. e., by the application of heated alkaline solutions while the min- eral is under partial or complete hydro-thermal fusion.

The conversion of hematite to magnetite. Magnetite differs from hematite in having a greater ratio of iron to oxygen, and in its crystalline system. Magnetite is found in the primary eruptive basalts where it is one of the essential characteristic minerals. By greater oxidation it is converted to hematite, which is frequent in the metamorphic rocks. When magnetite is found in the meta- morphosed rocks it is generally at points and planes of contact with eruptive dikes whose pressure, heat and percolating hot solu- tions have concentrated the iron from surrounding rock masses. When it constitutes ores in the metamorphic rocks, as in the Ver- milion series of schists, it is disseminated either as an ingredient of a massive basic rook, or it is interlaminated with siliceous sheets which are similar to those of "chalcedonic" quartz in the jaspilyte of the Keewatin schists. Structurally it repeats the characters of magnetite in the eruptive gabbro, on the one hand, and of the hematites of the Keewatin on the other. It is necessary to con-

22 Bulletin No. Vi.

aider therefore only the laminated condition, since the massive de- posits can be referred directly to dynamic and thermal agents. These laminated deposits of magnetite are embraced, sometimes in undoubtedly eruptive basic rock.* The change, therefore, from hematite to magnetite, through the action of heat and moisture, seems to be one of the common phenomena of metamorphism, and it is of the same general character as is shown above to have taken place in the other minerals of the Keewatin, viz., it is a step back toward the condition which the constituent iron molecules had when they were erupted with basic lava from the interior of the earth. This difference therefore is reducible to the same elements as those that have already been considered, and may be destroyed by hydro-thermal metamorphism.

Hence all the mineral differences, so far as they play any im- portant role in an inquiry into the possible genesis of the rocks of the Vermilion from those of the Keewatin, are resolvable into the same element, viz., an element that can be caused to disappear by the application of heat and moisture acting through the methods of hydro-thermal metamorphism; and we may not hesi- tate therefore, to consider the magnetites of the Vermilion schists to have been produced by that means from hematites which were once in the condition of those now mined in the Keewatin schists. This inference will also apply to the rocks that inclose the ores, and it may be said the mica-hornblende schists that are a pro- nounced feature of the Vermilion series are changed conditions of graywackes and chloritic and sericitic schists similar to those that characterize the Keewatin series. This great change was wrought by the approach toward, if not by the actual invasion of the lower strata by the plane of hydro-thermal fusion, which, according to the researches of Beade, Fisher and Darwin, t must exist near the surface of the earth at a depth which increases from age to age. In the first instance, this alteration must have taken place before the fracturing and crumpling which the Archean rocks now exhibit* by which they have been caused to present, nearly everywhere in Minnesota, sharp and nearly vertical angles of dip, affording ex- posure of their truncated edges, and it would have produced a shell which may be supposed, under normal conditions, to have encased the globe, consisting of recrystallized sediments. Such shell would be encased in another which, like the crystalline schists, does not exhibit any sign of previous complete fusion but

♦American Geologist, Vol. lit, p. 19.

tOompare Claypole's discussions in the American Geologist vol. i, p. 382, vol. ii, p. 28 and vol v, p. 83; also Reade idem, vol ii, p. 106, and LeOonte, id, iv. 38.

Ibon Ores Of Minnesota. 23

which has been affected in situ by heat, pressure and moisture. Wherever those early sediments were of basic materials the re- sulting schist-rock is largely hornblendic and biotitic and wherever the soluble silicates had been largely or wholly removed by the oceanic solvent action, leaving in the sediments a preponderance of fragmental quartz derived from earlier Laurentian shores, or when the silica was redeposited by chemical precipitation, the resultant rock is siliceous. Again,it will be seen by this that there can be no general, distinct, sudden line of separation between the crystalline schists and those strata that succeeded them in chronological order. But the crystalline condition would fade out upward into a non-crystalline condition. It would only be where there was bodily transference of fused material, in an intrusive manner, in the heated layers of the crust, or by the eruptions of molten rock from below the earth's crust, that crystalline rock would come into immediate contact with non-crystalline, (c.) Probable Parallels in other parts of the United States.

There are no parallels of the Vermilion ores, (i. e. the ores of the Vermilion series, or crystalline schists, ) in Wisconsin, nor in Michigan so far as known. There is a line of strong magnetic attraction running eastward from the Penokee gap, in Wisconsin, and considerable magnetite in the quartz-schists at Black JRiver Falls, but neither of these is believed to belong in so low a hor- izon as the crystalline schists, but rather to the age of the Animike (Taconic) which marks the extent and direction of the Mesabi range in Minnesota, where,likewisey magnetite accompanies some of the slates of the Taconic.

In New York state, according to the descriptions of C. E. Hall* the magnetic iron ores which are not titaniferous are found in a series of rocks which he considers "lower Laurentian," in dis- tinction from those of the labradorite rocks, or "upper Laurentian." These are quartzytes, hornblendic gneisses, and micaceous garne- tiferous gneisses. Their stratigraphic position, as well as their associated lithology, and their chemical qualities, seem to ally them with the magnetites of the Vermilion of northeastern Minnesota. These mines are very important, and have supplied large quanti- ties of the best ores of New York.

In New Jersey, according to the report of Dr. Kitchell, t the magnetic ores are found in a gneissic rock associated with horn- blendic and micaceous schists, with which they are interstra-

Report of the State Geologist of New York for 1884, pp. 23-34. 1885; also Thirty-second report of the New York State Cabinet, Albany.

♦ Annual report on the Geological survey for 1856, as quoted by Prof. Geo. H. Cook in Geology of New Jersey, 1868, p. 533.

24 Bulletin No. Vi.

tified. They are considered to be in the Azoic formation. Accord- ing to the special descriptions many of the New Jersey mines ap- pear to have wall-rocks of hornblende or hornblendic schist. Their chemical characters also resemble those of the magnetites of the Vermilion series in Minnesota.

In Pennsylvania, as described by Dr. Persifor Frazer, and by Mr. D'Invilliers, in Berks and Chester counties, nearly all the magnetic iron deposits (except those of the Mesozoic) are in gneiss or crystalline schists, in which they constitute sedimentary beds interstratified with the country rock. (Second Geological survey of Pennsylvania. Reports C4 and D8 ).

In North Carolina that series of schists and gneisses in which is situated the great Cranberry ore hank, in Mitchell county, com- pares both in the nature of the rocks and in the character of the ore, with the schists of the Vermilion. This belt of mica schists and hornblendic schists, associated with and blending into dark gneisses, extends apparently from Canada to Georgia, and in nu- merous places it is characterized by such magnetites. It is quite likely therefore that in the Northwest this horizon of iroir will in the future become more productive, and perhap3 will furnish some of the most valuable mines.

(2) The Hematites Of The Keewatin Schists.—

(The Vermilion range).

These hematites are the basis of all the actual mining that has yet been done in the state. They are therefore the mo3t important of the deposits considered in this report. They supplied in 1839, 844,638 tons of Bessemer ore, and the total shipment from the Minnesota mines since 1884, when the first ore was sent from Tower, to the close of 1890, reaches 3,227,347 tons.

(a) Nature of the Enclosing Rocks.

While the rocks of the Keewatin series exhibit a wi.de rt characters, extending, in structure, from the mostfimpm most massive, and in quality from the most basic to the most acidic, there is one character that pervades them all, and serves as a distin- guishing stamp of a common lineage — a chloritic or hydro-micace- ous element which gives them generally a greenish tinge when the chlorite prevails, and a silky sericitic luster and a smooth "tal- oose" feel in the hand, when the sericitic mineral is abundant.

Iron Ores Of Minnesota. 25

This element is sometimes screened by an incipient re-crystalliza- tion, and indeed it is lost entirely by local fusion, and intrusion of the molten rock among the adjoining schists. The former has taken place extensively near the bottom of the Keewatin schists, where they gradually assume the characters of the mica schists, or the Vermilion series underlying, and the latter has been ob- served on a small scale at some points near Tower.* On the up- per waters of the Kawishiwi river the gray wacke also becomes sub- crystalline in situ, making a massive, granitoid, red- weather- ing rock, approaching syenite. In the Giant's range of hills, about 15 miles south of Tower, such fused portions of the Keewa- tin seem to have been the source of the syenite rock of the hills, and the protrusion of this fused material was probably due to the intensified southwestern extension of the line of incipient crystal- ization mentioned on the upper waters of the Kawishiwi. f

Specifically the Keewatin embraces gray wacke, argillyte, chlorite schist, "greenstone," a syenite-looking massive rock, sericitic schist, agglomerates, porodyte, porphyritic massive rocks of va- rious kinds, and fragmental conglomerates. Of all these the "greenstone" is that with which we have most to do here, because in all oases the hematites are embraced in it. This greenstone takes on different aspects. It seems to be the same that in Michi- gan has generally been denominated dioryte. There are many places where it presents the aspect of an original crystalline erupt- ive rock as at Kawasachong falls, but that is not its most frequent condition, at least in those portions which are seen about the mines. On the contrary it usually appears as an "altered erupt- ive," and frequently it embraces angular and rounded fragments, large and small, of other rooks such as graywacke, argillyte and greenstone like itself. Such are noticeable at the railroad cut at Ely, and on the southeastern side of Ogishke Muncie lake, where it forms the lower portion of the great Ogishke conglomerate. In numerous instances the greenstone has been seen, as about Frogrock lake, to be striped by sedimentation lines, indicating the action of the ocean in distributing its ingredients.

As to the origin of the bulk of the Keewatin sediments, it was volcanic. This has already been stated in describing the Vermil-

Oomparo rock samples 868, 888 A and 868 E, 15th Report, p. 267. Also rock samples 1 iH). 15th Report, pp. 315, 816. No. 868 A Is illustrated In thin section on plate v.

♦Fifteenth report, pp. 347-354.

3*ee fifteenth annual report, p. 372; sixteenth report, pp. 05-99, 108, 306. 348. Thr term "Ogishke conglomerate" has been made to cover, In our opinion, two widely separated conglomerltic formations, viz. (1) the characteristically agglomerttlo por- tions of the Keewatin, about Ogishke Muncie lake, which In their western extension constitute the Stuntz island agglomerate, and (2) the basal conglomeritic portions of the Anlmike(Taoonic). which further east forms the lower slate-conglomerate of the Canadian "Huronlan."

26 Bulletin No. Vi.

ion, and in making a comparison of the Keewatin with the Ver- milion. The hot alkalinio waters of the Keewatin ocean acted readily on those volcanic ejecta. The silicates were decomposed in part and the insoluble residues were mixed as a siliceous pulp with other grains that were not decomposed. Whenever, and wherever the supply of material from subterranean sources was rapid this decomposition was not completed, and the sediments were simply distributed by the currents and waves in the same manner as clays and sands are now distributed, retaining largely their chemical composition and sometimes even their mineral structures. More or less change was effected, however, in nearly all cases, and the augitic and feldspathic and olivinitic minerals were reduced, by the deooctive action of the water, to chloritio and micaceous elements. If the volcanic supplies waned, or ceased, larger pro- portionate amounts of free silica were mixed with the more slowly accumulating sediments. This silica was derivable from any pre- existing granitic shores which might be attacked and eroded, or was precipitated from the oceanic waters which must have held in solution a large per cent of that derived from volcanic ejecta which had been decomposed.*

In general, therefore, the structure of the Keewatin rocks, whether they be in the form of gray wackes, schists, greenstones or argillytes, proves them to have been, in nearly all cases, laid down by the direct action of sedimentary forces, though their mineral character proves the sediments to have been largely of volcanic origin. There are also some massive, apparently original- ly eruptive portions which have never been disturbed by oceanic distribution since their extrusion from the interior of the earth in Keewatin time.

We have been furnished, by the courtesy of Supt. D. H. Bacon, of the Minnesota Iron Company, with the records of some of the drill-holes made by the company to explore underground the ore-lodes at Tower. Many have been made since these were transcribed, but those which follow show not only the method of the exploration but the physical structure, and especially the fre- quent alternations in the nature of the enclosing rocks. These records were kept by the superintendents of the drills at different times, Messrs. Prince, Cole and Wilcox, and the descriptive terms are those which they employed. The strata have such positive and evident characters, and generally are so contrasted in lithology that these descriptions may be accepted as correct.

Compare "On a possible chemical origin of the iron ores of the Keewatin in North* eastern Minnesota." American Geologist. Vol. iv, p. 201.

Iron Ores Of Minnesota.

Diamond Drill Sections At Soudan.

Hole A-rprilled in 1887]; angle 51°; vertical distance 81 ft; coet $734.49; average cost $7.06 per foot.

At The Stone Mine.

Kind of rook.

Soap rook

Jasper

Red soap rook

White soap rook

Soap rook

Jasper

Soap rook

Jasper

Soap rook

Jasper

Soap rook

Jasper

Soap rook

Jasper

Soap rook

Light slates

White quartz

Jasper.

Quartz

Soap rook.

Jasper

Thick-

ness.

ft.

in*

Depth.

ft. in.

54 9!

95 Id

Hole B-rprilled in 1887]; angle 45°; vertical distance 92% ft; oost $724.- 44; average cost $5.64 per foot.

Marked [

At The Ely Mine.

Kind of rook.

Jasper & mixed rock.

Chlorite schist

Ore

Quartz.

Chloride schist (red)

Jasper

Ohloritic schist (red)

Ore

Ohloritic schist (red) Ore and 4 in. jasper.

Jasper

Ohloritic schist (red)

Ohloritic schist

Jasper

Ore

Jasper

Ohloritic schist

Jasper

Thicli

ness.

ft.

in.

Depth.

ft. in.

95 8

Hole C — [Orilla in 1887]. Angle 45°, Tertioal distance 284 feet 4.5 inches, oost $674.88; average cost per ft., $1.71. Diamonds oost $315. About 75 paces N. £. of W. post sec. 26, 62, 15. 1740 ft. £. of £. end of pit.

At 8Tuntz Mine.

Kind of rook.

Surfaoe.

Copper scales about 20ft.

Ohloritio schists. . . .

Thick-

ft. in.

7 0

Depth.

ft. in.

895 2

402 2

Hole D— [Drilled Deo. 5, 1887-Jan.

4, 1888;] angle 65°; vertical distance

320 ft. 3 in.; oost, $1,859.25; average

oost per ft., $3.85. Depth, 353.4ft.

Marked [

at ely mine (Between Tower and

Ely).

Soap rook

Ore

Fe. 67.56.

P. 158

Si. 110. . . .

Soap rook Jasper , Soap rook Jasper Soap rook Jasper

ft.

in.

ft. in.

Bulletin No. Vi.

Diamond Drill Sections At Soudan.

Hole E— [Drilled January 5th, -2 1st 1888]; angle 76° 45'; vertical die- lance, 826 ft. 6 in.; cost $722.18; av- erage cost per foot, $2.15.

Marked [ ].

at elt mine from same point as D.

Kind of rook.

Soap rook

Ore.

Soap rook

Jasper

Soap rook Jasper . . . Soap rock

Ore

Soap rock

Thick

m

ness.

ft.

in.

Depth.

ft. in. 20 0

Hole H— [Drilled May 12th-June 30, 1888]; angle 27*30'; vertical dis- tance 193.9 ft; direction of hole S.

At Armstrong Vein.

Kind of rock.

Soap rook

Jasper

Soap rook

Jasper

Soap rock

Jasper

Soap rock

Jasper

Ore

Jasper

Soap rock

Suartz hloritic schist

Hole F— {Drilled Jan. 31-Jone 30, 1888]; angle 28°; vertical distance, 397 ft. 8 in.; direction of hole, N. E. byN.

Marked [ ].

At East Towkb Dock.

Kind of rook.

197 8

Soap rock

Jasper

Soap rock ,

Jasper

Soap rock

Quartz

Soap rock

Jasper

Soap rock

Jasper

Soap rock

Quartz

Jasper

Soap rock

Jasper

Soap rock

Jasper

Quartz

Red soap rock

Ore (Fe 66. 71; P. .090

Si. 2. 02)

Soap rock

Jasper

Soap rock

Jasper

Soap rook

Ore (Fe. 68. 9; P. 130

Si. 58)

Soap rook

Jasper

Soap rock

Ore

Soap rook Jasper Ore Jasper Jasper Soap rook Jasper

Depth,

ft in.

75 0

Iron Ores Of Minnesota.

Diamond Drill Sections At Soudan.

Hole M— [Drilled July 28- Aug. 7, 1888]; angle 38°; vertical distance 80. ft. 8 in; direction of hole, south.

Marked [

].

At Armstrong Vein.

Kind of rock.

Jasper

Soap rock.

Jasper

Soap rook

Jasper

♦Clay and gravel.

Thick- ness.

Depth.

ft. in.

ft. in.

Hole N-[DTilled Aug. 2-Sept 20, 1888]; angle 45°; vertical distance 716.5 ft; direction of hole, east.

At Gravel Pit, Near Section House.

Kind of rook.

Gravel

Gray slate

Quartzyte

White quartzyte , Gray slate

Thiok-

ness.

ft

in*

Depth.

ft. in.

*Supt. Bacon says it could not have been clay and gravel, but was prob- ably a soft breccia.

Hole K.— [Drilled June 29-July 21, 1888]; angle 35°; vertical distance, 100 ft., 8 in.; direction of hole, south.

Marked f ]

At Armstrong Vein.

Kind of rook.

Soap rook.

Jasper

Soap rook .

Jasper

Ore.

Jasper — Soap rock.

Jasper

Ore

Hole L.— [Drilled July 31-Aug. 11, 1888]; angle 16°; vertical distance' 62 ft., 3 in.; direction of hole, north*

Marked [

]

At North Lee Stock Pile, Same As J.

Kind of rock.

Soap rock

Jasper

Soap rock

Jasper

Soap rock

Jasper

Mixed ore and jasper Jasper

Thick

nees.

ft.

in.

Depth.

ft. in.

Hole I— [drilled June 1-June 18, 18881; angle 29°; vertical distance, 157 ft 6 in.; direction of hole, N.;

At South Lee Mine.

Kind of rock.

Soap rook Jasper.. .. Soap rook Poor Ore. Soap rock

Thiok- ness.

Depth.

ft in.

ft in.

Hole J— Drilled June, 1888 J; angle 30°; vertical distance, 123.5 feet.

Marked [ ].

At North Lee Stock Pile Dock.

Kind of rock.

Soap rook Jasper — Soap rock

Jasper

Ore

Jasper

Thick- ness.

Depth.

ft in.

ft in.

Bulletin No. Vl

Diamond Drill Sections At Soudan.

Hole X— [Drilled Dec 7-Deo. 15,

1888]; angle — ; vertical distance, ; direction of hole, south.

Marked [ ].

At South Use Vein.

Kind of rock.

Stand pipe

Soap rock

White quartzy te

White quartzy te and

soap rock

Soap rock

Thick

ft. 1

in.

Depth.

ft. in.

208 1

Hole 2— [Drilled Sept. 27— Deo. 1, 1886.] Angle 60°; vertical distance 303ft. 6in. Direction of hole, south.

AT END OF NO 2, let LEVEL. BBEITUNG.

Kind of Bock.

Thick- ness.

Ore and jasper —

Jasper

White q'rtz jasper

Jasper

Ore

Jasper

Ore and jasper

Ore

Jasper

Soap reck

Jasper

Ore and jasper

Jasper

Soap rock

Jasper

Soap rook

Jasper

Soap rock

Jasper

Soap rock

Ore and soap rock. .

Sap rock

Clean ore

Soap rock

Jasper

Soap rock

Jasper

Soap rock

ft. in.

Depth.

ft. in.

Hole Z- [Drilled in 1888]; angle 82 ; vertical distance, 342 ft; direction of hole, north.

At No. 3 Shapt.

Kind of rock.

Stand pipe

Soap rock

Jasper

Soap rock

Soap and paint rock.

Soap rock

Ore

Paint rock

Soap rock

Paint rock

Soap rock

Jasper

Soap rock

Jasper

Soaprook

( Fe. 65.10 lst6ft}P. .076 (Si. 5.93 Ore last (Fe. 67.190

1U, "(Si. 1.44

Paint rock

rasper

Soap rock

Jasper

Soap rock

Jasper

Soap rook

Jasper

Quartzy te

Soap rock

Jasper

Soap rock.

Jasper

Soap rock

Jasper

Paint rock

Jasper

Ore

Soap rock

Jasper

Paint rook

Jasper

Ore

Jasper

Ore

Jasper

Paint rock

Ore

Ore and jasper

Thick- ness.

ft

f

in.

Depth.

ft

24 0

in.

358 11

Iron Oses Of Minnesota.

Diamond Drill Sections At Soudan.

Vole O— [Drilled April 2nd— Hay 28th, 1888); angle vertical dis- tance 381.8 ft: direction of hole N.

foap rock.

Soap rock.

Soap rock,

Quartz

Soap rock. Quartz

Soap rock.

Soap rock.

Soap rock.

Soap rock.

Soap rock.

Ore

Soap rook

Soap rock. Jasper . . . Soap rock

Soapatone

Ore

Paint rock Jasper

Hole EB-tDrilled May 8tb-June 26. 18891; angle 27°; vertical diatanoe 196 ft; 897 (t. N. EL of H hole.

Snap rock..

Soap rock .

! Paint rock..

Soap rook . .

Jasper

'Soap rock..

! Jasper

,Soap rock, .

I Jasper

'Soap rock . .

'Jasper

ISoap rock. . Jasper

Ore..

Jasper

Ore and Jasper.

Jasper

Quartz

Soap rook and paint rock

Hole CC-IDrilled April 5th-April 24th, 1889;] angle 10" 30'; vertical diatanoe 41 ft.. 4 in.; direction of hole— south. 227 ft north of west end of Montana pit.

HoIel>D-[Dril1ed April 26th— May 13th, 1889;] angle 27*': vertical dia- tanoe 125 ft.. 8 in; 227 ft. north of east end Montana pit.

Kind of rook.

Thick-

Depth.

Kind of rock.

Thick-

Depth.

ft. in

181 9 14 7

ft. in.

180 8 212 7 2'J7 2

Soap rook.

rt. i.i

228 2

35 9 8 (

ft in. 228 2

OUloritic schist

( Fe.=68.45 I P. 0.48 ( Si - 1.69

275 10

Bulletin No. Vi.

Diamond Drill Sections At Soudan.

Hole T -[Drilled Sept, 26-Dec. 6, 16881; angle 36°; direction of hole, north; vertical distance, 588.5 feet.

At Stone Shaft No. 3.

Kind of rook.

Standpipe

Soap rook

White quartzyte —

Jasper

Soap rock

Jasper

Soap rook

Jasper

Soap rock

Jasper

Soap rock

Jasper

Soap rock

Jasper

Soap rook

Jasper

Soap rock

Jasper

Paint rook

J Fe. 68.40 10th ft/3 P. .055 (Si. 1.40 re ? Fe. 67.85

Paint rook

Jasper

Ore

Ore and jasper

Jasper

Soap rock

Jasper

Soap rook

Jasper

Soap rock

Jasper

Hydro mica schist. . .

Thick- ness.

Depth.

ft. in.

ft. in.

306 (i

324 i,>:

347 io;

367 6!

406 8;

427 . 8

521 9,

Hole U— T Drilled Oct.19th-Nov.31st, 18881; anrle,30; vertical distance, 206 ft.; direction of hole, south.

Marked [ ].

At South Lee Mine.

Kind of rock.

Thick- ness.

Depth.

ft.

Soap rock 74

Soap rock and

white quartzyte.

Soap rock

Paint rock

. ( Fe. 63.18 Ore ] P. .045 ( Si. 6.42

Paint rock

Jasper

Soap rock

iu.

ft.

in.

0, 84

Oj 233

O

j 248

O

Hole 1 -[Drilled Aug. 9— Sept. 23, 1886.1 Angle 45u; vertical distance 164.5ft.; direction of hole, east and down.

AT END OF NO. 2, 1st LEVEL BREITUNG.

Kind of Rock.

Thick- j I ness.',

ft. in.;

Jasper ; 118

Glean ore i 2

Mixed ore j 1

Jasper 18

Glean ore 1

Mixed ore j

Jasper j 7

Soap rock 10

White quartz 6

8oap rock. Ore and quartz Jasper. .

f,

o;

0'

1; r

Depth.

ft. in.

To

Ison Obes Of Minnesota.

Diamond Drill Sections At Soudan.

Hoo AA— [Drilled December 16th, 1888 — May 11th, : - angle 2 1";

vertical distance 177 ft; started from same point aa X.

Stand-pipe

Soap rook

Quartz & soap rook .

Soap rook.

Jasper

Soap rock.

Jasper

Soap rook

Soap rook

Soap rook ""!!."! 94 11 :

<Jii;irlz k eoaji rook . 7 10 i

Soap rock 100 0 i

Quartz A soap rock..

Hole FF-[Drillel May 14tb— Mayl

M5tk, 18891; aoRle 49" 30, vertical dis- tance 185 ft. 2 in.; 227 ft. N. of E. end of Montana pit.

Soap ruck

Quartz

Soap rook

Soap rook . ,

(Ffl-68.70 Ore 1P-.065 8 7 269 1

( Bi-.75

Hole 6-tDriUed Nov. 16-Nov. 26, 1867]; angle 50°; vertical distance 80 ft, 9 inches; direction of hole, north.

Kind of rook.

Thick-

Depth.

ft. in. 87 5

ft. in

Hole BB— [Drilled March 8th— May 2nd, 1889!; angle 4," 30'; Vertiosl distance 510 ft. 1 in.; direction of hole, north. Drilled on same line aa hole Z.

at no. 3 SHAFT.

Kind of rock.

Thick-

fi.

Depth.

Stand-pipe . .

Jasper o

Soap rock ' 91

Ore 9

Jasper 10

Soap rock 28

Jasper 3

Soap rock 110

White quartz 2

Soap rock i 85

White quartz 1

Soap rock 20

Paint rock 12

Ore 6

Jasper 3

Ore 3

White quartz 2

Jasper - 1

Ore 15

Jasper 6

Paint rock 2

Jasper 6

Soap rock 1

Jasper 62

Soap rook 4

Jasper 19

Soap rook 3

Jasper 31

Soap rook 3

Jasper 14

Soap rock 42

Jaaper 3

Patnt rock 11

Jasper ' 1

Ore 14

Soap rook ! 11

Ore 7

Soap rook 1

Paint rock 0

Ore i 0

Jasper. 3

Ore 1

Soap rock . 7

Jasper 6

Soap rock 74

Bulletin No. Vi.

Diamond Drill Sections At 80Udan.

Hole 9— [Drilled Dec. 27-Jan. 22, 1889]; angle 1°, 80 in; vertical dis- tance, 6 ft., 10 in.; direction of hole, south; started from drift on 2d level of No. 7 shaft, 114 ft. from surface, measured on an incline.

Kind of rock.

Jasper

Soap rock and jasper.

Soap rock

Jasper

Soap rock

Jasper

Soap rock

Jasper

Soap rock

Jasper

Soap rook

Thiol

ness.

ft.

in.

Depth.

ft.

in.

Hole lO— [Drilled Jan. 23-Feb. 12, 1889]; angle, 45°; vertical distance, 154 ft., 3 in.; direction of hole, south; started from same point as No. 9, on second level of No. 7 shaft.

Kind of rock.

Jasper

Soap rock

Jasper

Soap rook

Jasper

Soap rock

Jasper

Soap rock

Jasper and soap rock

Soap rock

Jasper

Soap rook

Jasper

Quartz and jasper. . .

Depth.

ft. in.

Hole R-[Drilled Sept.5th-Deo.15th, 1888]; angle 35°; vertical distance 259.5 ft; direction of hole north.

At South Lee Vein.

Kind of rook.

White quartzyte

Soap rock

Sjuartzyte and ore.. . asper

Quartzyte and ore.. .

Jasper

Quartzyte and ore. . .

Quartzyte.

Jasper

Suartzyte re and quartzyte. .

White quartzyte

Ore and quartzyte. . .

Ore and jasper,

White quartzyte

Thick-

ness.

ft.

in.

Depth.

ft.

in.

Hole S— [Drilled Sept. 13th— Oct 30, 1888]; angle 62°; vertical distance 349.5 ft; direction of hole south.

At Armstrong Vein.

Kind of rock.

Soap rock

0 Jasper

Ill jOre and quartzyte.

1 Soap rock

5 ,Ore 11 Soap rock

Store

0|,Soap rock

10| .Ore and quartzyte.

10 'Jasper

10. Ore

'Jasper. 8 jSoap rock

White quartzyte. .

Soap rock

Jasper

Soap rock.

Chloritic schist. . . .

Soap rock

White quartzyte. . .

Jasper

Chloritic schist.. ..

Thick

ness.

ft.

in.

o

Depth.

ft. in. 12 O

O

272 11

Iron Obes Of Minnesota.

Diamond Drill Sections At Soudan.

Hole O— [Drilled Aug.ll— Aug. 29th, 18881; angle 88°; vertical distance 64.3 ft.

Marked [ ].

At Armstrong Vein.

Kind of rock.

Soap rook.

Jasper

Paint rock. Jasper.

Thick- ness.

Depth.

ft. in. 41 5 10 0 37 1

ft. in* 16 0 57 5 67 5 104 6

Hole P- [Drilled Aug. 15- Sept 2d, 18881; angle 9°; vertical distance 44 .91ft

At South Lee Vein.

Kind of rook.

Soap rook.

Jasper

Ore

Ore and jasper. Jasper

Thick-

ness.

ft.

in

Depth.

ft in* 207 5

Hole GO— prilled May lfr— June 1, 1889]; angle, 83°; vertical distance, 164 ft. 4 in; direction of hole, north; in swamp between S. Lee and R. R.

At South Lee, J4 Mile East Of Mine.

Kind of rock.

Dioryte (Graywaoke)

Paiut rook

Dioryte graywaoke. . Black rock and

magnetic ore

Thick- ness.

ft in.

258 10

17 9

13 6

11 9

ft in. 290 1

301 10

Hole 3-[Drilled Oct. 10-Oot. 22, 1887 J: angle 80°; vertical distance 124 feet, 2 inches; direction of hole, north.

AT TOWER MINE, WE8T END NO. 1, 3d LEVEL, IN CENTER OF VEIN.

Kind of rock.

Thick- ness.

Depth.

Clean ore

ft

in.

ft. in*

Jasper

61 2

Clean ore

Mixed ore

Clean ore

Clean ore

79 6

Jasper

81 6

Clean ore

84 6

Jasper

126 fc

Hole HH— [Drilled May 31— June 29, 1889]; angle, 51°, 41 in.; vertical distance, 258 ft.. 5 in. Started 800 feet west of CC and bored toward

ore vein.

At Montana Pit.

Kind of rock.

Quartz and soap rock

Quartz

Quartz and soap rock

Faint rock

uartz and soap rock

uartz

aartz and soap rock

Paint rock

Chloritic schist

Soap rock and

paint rook

Paint rock

Ore

Soap rock

Ore

Soap rock

Ore

Jasper

Soap rock

Paint rock

Ore

Paint rock

Soap rock

Paint rook

Soap rook

Jasper

ft. in.- 104 3

Depth.

ft in. 104 3

J 91

Bulletin No. Vi.

Diamond Drill Sections At Soudan.

Hole V— [Drilled Nov. lst-Nov. 15th, 1888]; angle 40°; vertical distance 262.2 feet; direction of hole, south.

At Same Place As Hole U.

Kind of rock*

Soap rock

Paint rock

Soap rock

White quartz y te,soap

rook and jasper.. .

Soap rook.

Hole W-|Drilled Nov. 19th-Dec 3d. 1888]; angle 53°; vertical distance 295.5 ft.; direction of hole, south. Started at same point as holes U &V.

Marked [. . ..]

At South Lee Mine,

ft. in.

Kind of rock.

Gray quartzyte

Soap rock

White quartzyte and

paint rock

Paint rock

Jasper

Paint rock

Jasper

Soap rock

Thick-

ness

ft in.

Depth.

ft. in.

Hole II— [Drilled June 6th— June 25, 1889]; vertical distance — direction of hole, north.

Kind of rock.

Dioryte craywaoke. .

Paint rook

Jasper

Dioryte graywacke. . Jasper & mag 'tic ore Dioryte

Thick- ness.

ft. in*

46 0 19 6

67 7

Depth.

ft in.

234 4J

As the holes were completed they were severally marked by iron rails inserted a suitable depth in the ground near the opening of the holes, and through these rails were drilled holes to distinguish them, the drilled holes having different intervals separating them, according to the accompanying records.

(1.) Macroscopic Characters. Outwardly this greenstone varies from a massive diabase-looking rock to a fissile, green chlorite-schist the fibers of which are elongated in a direction parallel with the geueral strike of the formation, but varying, in close proximity to masses of jaspilyte or of boulder masses of other rock, so as to wrap round them parallel to their outside sur- faces. It is most frequent as a green schist. As a chlorite schist it is almost free from free quartz, but at places more remote from the iron deposits it varies to a siliceous rock, the silica being fre- quently in the form of fine pebbles or grains of jaspilyte, and

Iron Obes Of Minnesota. 37

occasionally of vitreous quartz, and at other places taking the form of a white "talcose" novaculyte (No. 1557), in which the silica is so fine that the individual grains cannot be discerned, making a glossy felsyte, or developing porphyroidally. Also in the mines this green schist is replaced by a white soapy flour-like substance which has been considered magnesia by the miners, but which according to analysis of Mr. Herbert A. Wilcox, is princi- pally a hydrous silicate of alumina, the product of slow decom- position of the silicates of the surrounding rocks. This is found both at Tower and at Ely. This whiie kaolinic substance becomes gradually iron-stained, in some situations, and so completely charged with iron peroxide that it appears like a soft hematite ore. In this condition it pervades the mines and shares with the hematite itself in giving the prevailing red color to all the works. Following is the analysis of this white substance by Prof. J. A. Dodge.

White Kaolinic substance (Chem. ser. No. 211) found in the Tower mines. Survey Number 1449.

Analysis.

Silica, Si O. 62.05

Alumina, Alf Oa 27.55

Oxide of iron, Fe, O, 1.30

Lime, Oa O .88

Magoesia. Mg O .77

Potassa, Kf O 4.26

Soda, Naf O .31

Phosphoric Oxide, P2 06 .11

Water, HfO (chemically combined) 5.80

This greenstone causes some of the prominent elevations. It is firm and massive in some of the hills eastward from Tower and at the falls of Kawasachong it is the rock over which the water runs, all the way from Garden lake to Fall lake, (Nos. 356, 998, 999). Still further east it becomes fresher in crystalline character, and rises into numerous hills that run in a nearly con- tinuous range from the central part of town 63-10 to the south side of Ogishke Muncie lake where it apparently constitutes the Twin peaks in the northern part of town 646. Toward the east still further it is quite conspicuous as a hill range, and runs under the Animike and gabbro at the southwest end of Gunflint lake, giv- ing altitude to the Animike-gabbro hills in that neighborhood. There is some reason, however, for supposing that this eastern range of greenstone hills is more likely to belong to that belt of the Vermilion which is seen on the west side of White Iron lake. This consists chiefly in its association with occasional mica-schists, and with magnetitic rather than hematitic ore, and of the otherwise

38 Bulletin No. Vi.

anomalous discontinuance of the Vermilion series which appears on the west side of White Iron lake, in the southwestern part of town 63-10.

In company with the jaspilyte the green schist has suffered a crumpling and squeezing, or has been stretched and molded to con- form to the adjacent harder masses. At the Breitung opening and at the Tower opening, the finely jointed or basaltified structure, which the schist has been made to assume under this squeezing and stretching, is well shown. One photograph was made to illus- trate this at the Tower opening, and it is reproduced on plate L Analysis of the green rock enclosing the Keewatin ore.

The chemical composition of the green schist, in its massive condition, was ascertained from a sample (538 B.(H.)) from Sec. 4, 63-9. The analysis was made by C. F, Sidener,viz: (17th report, page 126.)

Silica, Si O, 50.47

Alumina, Alf 08 18. 45

Seequioxide of iron, Fet Os 2. 18

Protoxide of iron, Fe 0 7.74

Lime, Ca O 6 . 61

Magnesia, O 6.90

Potassa, K.O .80

Soda, Naf O 2.68

Phosphoric acid, P8 0B traces.

Water, flf O 2.84

Total % 97. 52

The following shows the composition of this rock at the falls of the Kawishiwi, south of Fall lake. It is rock No. 356, sometimes called the "Kawasachong rock." Analysis by C. F. Sidener.

Silica, Si O. 43. 96 per cent

Alumina, A J, Os 16.03 "

Peroxide of iron, Fef Os 10.50 "

. Protoxide of iron, Fe 0 8.73 "

Lime, Ca 0 9.54 "

Magnesia, Mr 0 6.56 "

Soda, Na, 0 1.62

Water,H80 1.84 "

Total 99.06 "

(2. ) Microscopic characters of the enclosing greenstone.

The illustrations of the microscopic characters are on plate v, figs. 4, 5 and 6. The first published microscopic examinations of any of these greenstones was that of Prof. M. E. Wadsworth, as follows: "A dark-gretn, compact schistose rock. The section is composed of greatly altered debris, apparently of diabase, the fragments resembling a fine gray altered tufa (trachytic). The section is now largely altered to chlorite, micaceous scales, quartz

Nn7

Iron Ores Of Minnesota. 39

and magnetite, of which the chlorite predominates, with the quartz second in amount. Notwithstanding the great alteration of the section its fragmental structure yet remains complete." This description is applied to rock 356, from Kawasachong falls.*

The determinations of Dr. Hensoldt indicate a more massive, at least a more nearly crystalline, rock, having the characters often assigned to original eruptions. The rocks 999 and 998 have been specially examined. They are from the rapids at the Kawasachong falls, on the south shore of Fall lake.f The ordinary appearance of these in this section, magnified about twenty-four and thirty diameters, is shown in figures 4, 5 and 6, on plate v.

Hornblende Dioryte.

Rock 999. — [Plate v. fig. 4]— The principal constituents of this rock are plagioclase, hornblende and a greenish alteration- product, which may be termed viridite. If we examine a section under a magnification of, say, 60 diameters we observe a grayish feldspathic matrix or ground- mass, in which numerous crystals of hornblende of the usual dark-green color lie embedded. These crystals vary considerably in size; some exceed one mm. in actual diameter while others are barely distinguishable on account of their minuteness; their shape is mostly that of elongated scales or prisms, though rhombohedral outlines are by no means uncommon. These horn- blende crystals have been rendered more or less tarbid by decom- position and have become clodded by ferric hydroxide or dust-like magnetite, as alteration products, but in the main their character- istics are preserved.

In addition to the hornblende crystals large irregular colorless patches, surrounded by a pale greenish fringe, are noticeable in the feldspathic matrix, and in many instances these colorleis masses present distinct hexagonal outlines. It is extremely probable that these are pseudomorphs after biotite, the latter having been com- pletely changed into calcite and greenish fibrous epidote. J

In the original condition of the rock the grayish matrix was doubtless a colorless triclinic feldspar (possibly labradorite) which has been rendered tarbid by partial kaolinization. Its optical properties are now almost completely destroyed, no twin-lamellation and only a very faint chromatic display being noticeable. A few small colorless hexagonal sections indicate the presence of apatite.

Bulletin No. 2, Minnesota Geological Survey, p. 123.

tFifteenth Minnesota report, p. 310. The locality for !H)7 (p. 393) Is wrongly given In the catalogue of rock samples It was from the same place as 996, but nearer Fall lake.

$A11 the smaller blotltc scales have been transformed Into chlorite or epldote, with- out a trace of calcite.

40 Bulletin No. Vi.

Dust-like grains of magnetite are scattered all oyer the field and a number of larger crystals with distinct cubical and octahedral outlines are likewise observable.

Rock 998. A hornblende-dioryte of similar structure and com- position as 999, but containing a perceptible admixture of quartz. The hornblende scales are much larger than in 999 but their feeble dichroism indicates a more advanced ohloritization. The feldspar is exceedingly turbid and has lost its optical properties, no twin- lamellation being perceptible in any of the crystals, but the forms of the original prisms are still preserved. The quartz-grains have a f ragmen tal appearance and do but seldom show rounded forms; they are small and easily distinguished by their transparency and brilliant polarization. This dioryte contains little if any magnetite, but we observe in the section numerous crystals of titaniferons iron, surrounded by a peculiar grayish-white alteration product. This is evidently 4;he same rock which has been briefly described by Dr. M. E. Wadsworth, under 356, in Bulletin No 2. of the state survey (p. 123). The writer has carefully compared the different sections (viz. 998 and 356) and has found in both the same miner- als, in precisely the same form and stage of alteration. Dr. Wads- worth, however, has failed to identify the titaniferons iron, mistaking it for magnetite. The latter invariably changes into rusty limonite and never forms a grayish decomposition product, which is a characteristic of titaniferous iron.

It has already been stated that some parts of the Keewatin schists have been subjected to pressure, folding and apparently nearly to fusion. At any rate they have been made to assume tue different shapes and outward structures that are commonly as- cribed to primary eruptives. Such appearances have been des- cribed at several places in the annual reports of the Survey. Plate I represents a jointage that resembles that assumed by basaltic rocks on cooling, seen in the green Keewatin schists where they have been exposed at Tower in the operation of the mines. This schist on the weathered surface is seen to crowd into all the ac- cessible sinuosities of the jaspilyte, and to conform in all respects toits exterior shapes. In other places about Stuntz bay (15th re- port pp. 314-317), the Keewatin sediments have been made to act the role of eruptive rock. They become massive, acquire a basaltic structure, and crowd over and cut across the schistose structure of the adjoining strata. The rock having this igneous manner seems sometimes to be involved, in the vicinity of Stuntz island, and on the mainland further west, in the agglomerate which there prevails, somewhat like a dyke, but really wedges out in a

Iron Ores Of Minnesota. 41

lenticular manner. Its contact with the agglomerate shows noth- ing noteworthy. There is nothing indicating any effect it had on the agglomerate, which shows the two rocks had nearly or quite the same temperature. There is simply an abrupt transition from a schistose coarse rock with boulders to one without boulders, of the same color, massive, or coarsely jointed in a basaltiform man- ner, and homogeneous in mineral characters. In other places the green schist seems to graduate into this eruptive-acting rock, and becomes there associated unconformably with graywacke and argillyte. A patch 30 feet across strikes diagonally across gray- wacke. It has a perfect basaltic columnar structure, and contains semi-rounded quartz grains distributed somewhat like quartz in a porphyry, though not of uniform size. It appears as if it could have been produced by the more or less complete local fusion of the materials of the surrounding rock (compare rock No. 1, H ).

The rook which is described below and designated an "altered minette or syenitic lamprophyre" (No. 868 A) was obtained on the southern slope of the "south ridge," near its western end, and its relations to the adjoining rocks are described on page 267, of the fifteenth annual report It is of the same class and origin as those already mentioned above. It graduates into the green schist of the region, and the green schist into argillyte. It is mainly mas- sive, but acquires, at exposed places, a schistose structure coinci- dent with the direction of the green pcbist. Feldspar crystals are developed in it in differing stages of distinctness. It also re- tains traces of its original fragmental structure in the forms of boulders that appear scantily scattered over its weathered surface.

Further stages of change in the sediments of the Keewatin have been noted about Kekekabic lake, where the feldspar is more per- fectly formed in idiomorphic crystals, making a porphyritic rock, which, rising massively and firmly above the surrounding sur- faces, shows on its weathered surface numerous included boulder- forms of different sizes and composition. Compare Nos. 1094, 1402, and others from Kekekabic lake, 16th report, pp. 100-105.

It appears that by some force the Keewatin beds were greatly compressed and folded. This pressure was accompanied by heat and moisture. The elements which were at first disintegrated to form the sediments were so far fused by this action that they were enabled to reunite, according to their chemical affinities, produc- ing, on cooling again, those crystalline minerals which before went to make up the sediments. In many cases the crystallization was not completed, but the process was interrupted, such interruption causing, apparently, the dimness of outline which sometimes these

42 Bulletin No. Vi.

re-formed crystals manifest, their shapes and their color and com- position not being sharply separable from the matrix in which they began to grow.

Rock 868 A.— (Plate v, fig. 6). — This is an altered minette or "syenitic laraprophyre" (of Rosenbusch), which occurs in various structural modifications. It is a compact, semi-crystalline rook with an approach to porphyritic development (as in most of the older intrusive vein-rocks) but assuming in some places an al- most schistose character. The prevailing color is a light greenish- gray, passing here and there into various shades of red and brown.

If we examine a section prepared from the typical greenish variety (868 A) we observe a turbid feldspathic matrix, finely granular or aphanitic, in which large porphyritic crystals of kao- linized orthoclase are embedded. The latter are, practically, pseudomorphs, as they are identical in substance with the ground- mass, from which they can only be distinguished by their outlines and their inferior translucency. Most of these orthoclase pseu- domorphs are idiomorphic, viz., bounded by their own crystal planes, which denotes solidification from an originally molten state.* Their optical properties are almost completely destroyed, yet in a few instances faint traces of the peculiar cross-hatching or pectination of monoclinic feldspar are noticeable between crossed Nicols. In addition to the orthoclase pseudomorphs we observe dark-green chlorite, in the form of elongated scales and irregular patches, distributed throughout the field. Examined with a half-inch objective these patches are found to possess a semi-fibrous or granular structure and to be associated with small grains of magnetite which are partly converted into yellowish and brownish limonite, causing a rusty stain. Whether this chlorite has resulted from the decomposition of an original biotite or horn- blende must remain an unsettled point till a section can be se- cured which shows either the one or the other mineral in its act- ual state of transition. It is possible that both biotite and horn- blende were original constituents of this rock, as in most of the minettes which have come under the writer's observation.

Hock 868. — This rock differs macroscopically from the one pre- viously described (868- A) in having an almost schistose structure; microscopically the resemblance is very close. We observe the sam e aphanitic matrix, enclosing porphyritic orthoclase crystals and

Orthoclase. requiring an enormous fusion-temperature, would be tin; first to sol Id if y in a cooling magma, thus its crystals could not possibly be modified externally by the crystals of any of the subsequently solidifying minerals. They may. however, be fractured or broken .

Iron Ores Of Minnesota. 43

greenish masses of chlorite, partly stained and discolored by rusty limonite. The orthoolase individuals are, however, in a more ad- vanced stage of decomposition and have been so completely meta- morphosed that evep their outlines have become indistinct, and, in many instances, quite lost. In No. 868 A we could still notice faint polarization colors in the kaolinized crystals, but in the present rock we have a total absence of chromatic phenomena.

There can be little doubt that 868 represents an older type of the same intrusive rock, as evinced by the more complete decom- position of its principal constituent, as well as its schistose struc- ture. If we were confronted by the latter circumstance alone we might hesitate to argue from it in discussing the problem of rela- tive antiquity, but the condition of the orthoclase crystals clearly points in the same direction. The process of kaolinization in ortho- clase, not exposed to surface weathering, is an exceedingly slow and gradual one, and perhaps no other rock-forming mineral af- fords a safer guide in determining the chronological order of met- amorphism in the ancient crystalline and panidiomorphic rocks. The question here involved is one of cardinal importance. Are all the types referred to in the state geologist's fifteenth annual report (pp. 264-268) viz. Nos. 868, 868 A, 868 B, 868 C, 868 D, 868 E and 868 F, modifications of one and the same rock? If so, did the par- ent-rock present these structural differences already at the time of its formation or were they effected by local changes in an origin- ally homogeneous mass? Furthermore, did the changes (if subse- quent and local) occur contemporaneously and gradually, or are they due to sudden complications after intervals more or less con- siderable? That any rock should, within the limited area pre- sented by 868-868 F, be so differently affected by contemporaneous agencies (whether sudden or gradual) seems utterly inconceivable; it would imply a bewildering complexity of conditions. Why, if one part of the parent rock was altered, by conditions which must have prevailed for ages, were the others not si milarly affected ? Why should a well-characterized minette— one of Rosenbusch's intrusive vmn- rocks — pass into a coarse conglomerate on the one hand and into a fine slate on the other? If we are really here dealing with con- temporaneously formed rocks it would be absurd to attribute to these rocks a sedimentary origin. Besides, it may be asked, did sedimentary rocks, in the commonly accepted sense of the teim, really exist at that remote period? The writer is inclined to doubt this. Sedimentary rocks, formed of the material of previous plutonic or metamorphic masses, imply the existence of islands or conti- nents of which they are the detritus, and it is exceedingly improb-

44 Bulletin No. Vi.

able that extensive land-areas should have risen above the ocean- level at so early a stage of oar planet's history.

Rock 1557. — This is a whitish-gray quartzif erous talc-schist, com- posed of a fibro- granular, almost aphanitic, matrix, in which numerous angular quartz grains are imbedded. The latter are quite pellucid and their brilliant polarization-colors form a marked contrast with the isotropic matrix. It would seem, however, as if quartz or amorphous silica was also present in the matrix, not in the shape of distinct granules, but in a finely divided, almost jaspilitic condition. The talc is either an alteration-product of augite, hornblende or enstatite. Compare the 18th annual report, p. 42. This rock was obtained at the roadside, where it is crossed by the railroad, near the Tower mine; on the south slope of the "North ridge," and represents a not infrequent condition of the finer part of the Keewatin sediments.

Rock 869. — A soft, greenish-gray, chlorite-schist, with an almost slaty cleavage. It is composed of closely matted scales of chlorite and talc, but the structure is so minute that a magnification of from 300 to 700 diameters is required for its examination. In sections cut parallel to the plane of cleavage the chlorite-scales appear pale green and we notice that their boundaries are so indistinct that in most instances it would be difficult to ascertain the pre- vailing forms. Many of the chlorite-scales contain needle-like crystals of rutile, derived probably from previously existing titani- ferous iron. The latter exhibit the yellowish translucency peculiar to rutile, if examined with an "eight-inch" objective. The talc- scales are perfectly colorless, well defined in outline and free from enclosures. They do not show the faintest pleochroism, but polarize in feeble tints of blue and gray. In this latter respect they differ from the chlorite, which is totally isotropic There are grounds for believing that this rock was originally an am- phibolyte consisting almost exclusively of hornblende (with a smaller admixture of titaniferous iron). The hornblende was changed into chlorite which is now being converted into talc, the metamorphosis being about half completed. Such a rock would be ultimately transformed into a regular talc- schist. This rock was obtained at the west end of the "south ridge."

JBocA: 919. — A chlorite-schist, almost identical in structure and composition with that described under 369. It shows the same close interfoliation of talc and chlorite, but the chlorite is better developed than in 869 and predominates over the talc. This rock is quartz-bearing (a feature which we did not observe in 869) but the quartz does not occur as a constituent of the chloritic strata.

Iron Ores Of Minnesota. 46

but forms thin sheets or layers interposed between the latter. This is from the railroad cut south of the Stone mine.

Rock 864.— A dark, heavy chiastolite-slate, resembling the so- called "knotenschiefer" of German petrographers, as it presents numerous small lenticular concretions along its cleavage (which is somewhat irregular and fissile). Its principal components are chiastolite, talc, chlorite and an opaque "carbonaceous" substance, which is probably finely divided magnetite. The chiastolite crys- tals have mostly rhombohedral outlines, but are otherwise almost in the condition of pseudomorphs as they have lost their trans- parency and appear to be partly converted into a semi-fibrous or granular decomposition product. It is to these chiastolite crys- tals that the peculiar "knotty" structure of the rock is due, as they form the substance of the lenticular concretions. The hard- ness of the latter almost equals that of quartz. The talc-scales are comparatively large, and even more pellucid than in 869, showing the same absence of pleochroism, but polarizing in more lively colors. Chlorite is now only a minor accessory (having in the writer's opinion been mostly converted into talc); its color is a muddy green but no distinct forms are anywhere recognizable. This is a rare rock in the Keewatin. It is from the south shore of Jones bay.

The agglomerates (sometimes properly called conglomerates) which abound in the Keewatin are of problematic origin. Some of them, particularly those which embrace numerous masses of rock, large and small, which are greenstones and resemble closely the rock in which they are embraced, are found to constitute a large part of the more massive portions of the formation, and may be supposed to be referable to submarine volcanoes which ejected not only great quantities of tuff and volcanic bombs which fell at once into the surrounding ocean and were by it transported to more distant parts, but also vast outflows of basic lava. All these products were subjected to the violent chemical action of the heat- ed atmospheric waters or to the alkaline oceanic waters into which they fell. Such periods of agitation were favorable for the rup- turing of the prior formed beds, whether of siliceous or basic com- position, and whether the result of chemical precipitation from oceanic water or of mechanical transportation and deposition, and for the mingling of such materials with the accumulating volcanic products. The rounded stone which is represented by 2 B (H) is but one of thousands that could be extracted from the conglom- erates of Ely and Stuntz islandst The enclosing rock is in the main a silky schist varying by reason of its finely siliceous texture

46 Bulletin No. Vi.

and composition to a rock like 1557 (described above), and to a more siliceous and firm felsyte, like that seen in this pebble. Wherever the pebbles of these conglomerates consist of non-basic materials they seem to have been of mechanical origin and deri- ved from older strata existing near. One of the most frequent* and yet one of the most perplexing facts, in connection with these conglomerates, whether of acid or of basic pebbles, is the identity of the lithology of the pebbles with the strata in which they are embraced. That the rook that furnished the pebhl themselves was of fragmental origin originally, is indicated, stated below, by the presence of fragmental grains of quartz. In this case, however, and in nearly all others where these sili- ceous pebbles have been examined, there is evidence of the pre- cipitation of much of the silica from solution, this process going on simultaneously with the fragmental accumulation. We have thus three stages of accumulation proved by these boulders — let, that of the smallest fragmental grains; 2nd, that of the boulders; 3d, that of the strata that contain the boulders — and in all of them the physical and chemical conditions were so similar that there can be discovered no essential difference in the rooks which were produced. This is analogous to the shattering in situ of the last formed layer of jaspilyte (fig. 8), by some force which was not able to remove the fragments, but which allowed the immediate resumption of the process of accumulation (in this case chemical precipitation) which preceded, and which, indeed, formed the shattered layer itself; but it is more nearly identical with that process which both shattered and removed the jaspilyte beds from their places and scattered the pieces among later formed jaspilyte. Rock 2. B. (H.)— [See the fifteenth report, p. 304.]— This re- markable rock occurs in the shape of rounded masses or boulders in the schist of Ely island, and may be termed a porphyrinic felsyte. It is composed of a micro-felsitic basis, which, even under high powers of magnification, is not separable into true individualized parts but consists of indistinct granules and fibres, which transmit a feeble, fluctuating light. Embedded in this matrix are crystals of whitish orthoclase and a few rounded quartz- grains. The orthoclase crystals are so turbid that it is easier to recognize them with the naked eye than under the microscope, where they can only be distinguished by their outlines. They appear to have been completely kaolinized and subsequently indurated by silica, deposited between the disintegrated particles. In reference to the rounded quartz-grains we can see at a glanoe that they are water-worn pebbles. They vary in diameter from

Iron Ores Of Minnesota. 47

that of a pin's head to that of a large pea, and contain numerous fluid-enclosures, arranged in lines, exactly as in rock-crystal and in the quartz of granites. There cannot be the shadow of a doubt that these quartz-grains existed previous to the formation of the rock in which they are embedded and that they are older than the other constituents. The mere fact of their presence suffices to demonstrate the sedimentary origin of this rock, or at least to exclude the hypothesis of a possible igneous derivation. These grains mast have been introduced during the process of the for- mation of the rock, which probably was once in the condition of a soft sediment; the interstitial silica may have been chemically precipitated but the orthoclase may be a product of intfa-molecu- lar or crystallo-genetic activity.

(6.) Structure and character of the hematites of the Keewatin.

(1.) — Structural features of the ore. — Here will be mentioned only the physical aspects of the ore- bodies. In general the ore lies in lenticular bodies elongated northeast and southwest in parallelism with the schists. These vary in size from mere pebbles to belts that can be traced sometimes over a mile continuously. When the bodies are small they are apt to be so poor in iron that they are not mined. Indeed it is true that most of the jaspilyte is too siliceous to be valuable as ore, the silica being simply stained by iron in such proportions as to make reddish and pinkish shades. The large bodies that are worked at Tower have such lean spots that they are rejected, and also such highly siliceous spots that they are not even mined. Probably three- fourths of the whole jaspilyte mass, as it occurs in the ridges at Tower, is worthless as iron ore.

This siliceous, ribboned jasper is made up of all possible vari- ations between pure silica and pure hematite, the different colors being due to the different relative proportions. Its parti-colored glaciated surfaces are very beautiful. Its serpentine windings are plainly exhibited. (See fig. 22, p. 257, 15th Rep. and fig. 5, 17th Rep.). Being the firmest portion of the hills it forms their tops after the destructive erosion of the glacial epoch, and frequently for long distances it can be walked over without any obstruction or interruption other than a fallen tree or a mass of drift boulders. The silica and hematite bands run parallel to themselves, but are bent, re-trorse, incurved, again revolute, abruptly broken and rece- mented; faulted minutely, any separate band independently faulted, or the entire mass suddenly jogged to the north or south.

The relations which these siliceous bodies sustain, stratigraphi-

Bolletix So. Vi.

cally, to the enclosing rock are interesting. Generally they are entirely and abruptly distinct from the greenstone, or green schist that encloses them. Occasionally they are cat across, or interbanded, nearly parallel with their own direction, by bands from six inches to ten feet in thickness, of the green schist In these cases* there is no intermixture of the schist with the jaspilyte. The figures below (figs. 1 and 2) represent the alterna- tions that may sometimes 1

seen at Tower between the green schist and the jaspilyte. In some cases alternating beds of jaspilyte are good ore and in others they are too siliceous. These figures were sketched at Tower, one from the east wall at opening No. 5 and the other from the east wall of opening No. 6, known formerly as the East Ely and West Ely mines. Each one of these beds of jasp-

Compart- tliu 1Mb report pp. 225-2M.

Iron Ores Op Minnesota. 49

lyte has a fine lamination which ia much contorted. The schists which are pervaded by a schist >se structure, when not reddened by iron, and which when reddened are less schistose and "baked," though soft, do not manifest, so distinctly, a finer internal lamination. Thefonr-inoh bed of schist, at the loft of figure No. 2, runs the whole length of the mine, and even appears on the stripped surface east of the opened pit, traceable 500* or 600 feet altogether. At the rest opening farther east, a similar alterna- tion of beds of schist and beds of ore can be seen, the schist beds being three in number and from six to ten feet thick, the whole width across tbe ore mass being from 75 to 100 feet

While these jasper lenticnles are generally free from the green sohist, yet they graduate downward in eizs, and pass to mere pebbles and grains no larger than a pin-head. In this finely dis- seminated state they are mixed with tbe sohist, and arranged in other places in sedimentary strata. When they are coarser, and yet not in their native places, they c&uBe a conglomerate compo- sition in the green schist, and in these finer conglomerates they help to constitute the graywackes of the formation. At points somewhat remote from the main ore masses the jaspi- lyte rapidly degenerates as to its content of hematite, and becomes simply chal- cedonic quartz. At the same time it is mingled with grains of distinctly vitreous, crystalline silica which seem to have a differ- ent source. Figures 3, 4 and 6 illustrate the man- ner in which some of tbe jaspilyte masses are dis- seminated through the schists*. In these fragments tbe jaspilyte shows its original bsd- ing, and angular outlines indicating that it was not far transported from the place of its origin, and was soon buried under accumu- lating schists after it was broken up and distributed.

Explanation, of Figure 3. S. Schist, its fibrous and wavy structure bending around the jaspilyte in- alfsnres. J. J wpilyte in angn'ar fragments, showing nonoomformable earlier fins

From A. Wlncliell's

1. 1886, Fifteenth Bepurt, Minnesota Si

Bulletin Mo. Tl

QQ. Quartz veins, vitreous sod distinct from the quarts, of the jaspilyte. QiL Quartz. JQ. Jaspiry quartz.

The figure was sketched From nature, NE. part 8 . W. If, SE. %, Sec. 20,62-15, south shore of Vermilion lake.

Explanation of Figure A.

This figure represents the structure of schist at the same point as figure & 8. Schist, with bending; structure accommodating itself to the jaspilyte

J. Jaspilyte, evidently introduced while the layers of schist were forming broken from some preexisting formation when they had already received thnir banded structure.

A. Here there may be seen a local graduation of the schist into quartz, 'showing that some quartz was accumulating contemporaneously with, the

Explanation of Figure 5.

Thin was sketched about 20 rods northeast from figures S and 4. J. Jaspilyte, with broken outlines, forming a coarse breccia. S. Schist.

Iron Ores Of Minnesota.

In all these cases it will be noted that the jaspilyte, which is the rock which embraces or accompanies the ore bodies whether valua- ble as ore or not, and whether large or small, and whether in its native place or transported and embraced as foreign bodies in the green schist, is a foreign substance brought from its native place by some unknown force and deposited in the finer sediments of the schist while they were being accumulated. These are unlike the coarse, bedded, long-extended alternations seen in figures 1 and 2, which show that the jaspilyte masses are in their native places, and that the force that formed them alternated with the force that formed the schist. It is apparent, again, that the larger bodies which lie now in situ among the schists, were the parent sources for the fragments that, at other points, are scattered through the schists, and that some force, or succession of forces, was active, which was capable of breaking up the masses in situ, and of distributing them at once among the still forming sediments of the same age. This disruption of the jaspilyte bodies involves the previously formed strata of the schist, as will be evident by the following figure (fig. 6) where in the same brecciated mass can be seen jaspilyte and green schist It is but rarely that breccias con- sisting almost entirely of the schist in angular pieces are found, but such occur near the Breitung mine (opening No. 13) and such are represented by rock sample No. 1,563.

Fig. 6.— Breccia containing green schist and jaspilyte pieces.

Explanation of Figure 6. Sketched from a fragment in the damp at opening No. 1.

1. White obaloedonic silica, thinly and sparsely banded with hematite.

2. Conglomerate and breccia of green schist and brown jaspilyte. The

52 Bulletin No. Vi.

black part represents green schist. Some of the separate pieces are sub- rounded, others are elongated and sheeted. 3. White silica and hematite, beautifully banded.

The bre,ccia of green schist and brown jaspilyte (No. 2 of fig .6) was accumulated during a general period of accumulation of jaspil- yte, indicating some rupturing agent that affected both rocks. Indeed there are many evidences that there was a force, whatever it was* that was capable of fracturing the last laid down thin layer, with- out affecting the others, also that some force was active in ruptur- ing and transporting in a common manner both the acid jaspilyte and the basic schist. At many places fragments of the jaspilyte may be observed scattered unconformably in the schists, and at other places a breccia of schist and jaspilyte may be seen, particu- larly in the opening southwest from the old Breitung mine, but it is rare to observe unconformable pieces of the green schist em- braced in the jaspilyte. This rarity of the green schist in thia situation may have been due to the greater ease with which it waa disintegrated and lost in the general sedimentation.

Thus far the most marked and evident relations of the schist and jaspilyte have been mentioned. It has been stated that they were accumulated under the operation of an interrupted force, or a force- acting on different objects uniformly, one result being suspended while tfye other was transpiring. That is the most evident and most frequent condition. The places separating the great jasper lodes from the country rock are distinct, the transition is abrupt and complete in the narrowest possible space, the separated sur- faces being very often slickensided, showing some movements ia one mass in which the other mass did not participate.

We have now to observe that occasionally there is a sedimentary alternation more minute, and that the distribution of the materials of the jaspilyte was cotemporaneous with that of the green schist,, and was due to the same agent,* whatever may have been their sources. This fact it required long search to establish. The first observation of this intermingling in definite strata formed by sed- imentation was made at the railroad cut south of the old Ely mines (now openings No. 5 and 6) at the Minnesota mine, and it is illustrated by rock No. 894. This inter bedding of schist and jaspilyte, the latter being somewhat purple, extends along the rail* road as far east as to the old Stone mine ( now openings Nos. 2 and 3) where it is again well-exposed (see rock samples 91>). Here the jaspilyte passes by gradations into the green schist by mingling of the minute granular parts, the resulting rock being neither schist

Compare the annual report pp. 22i. *J24.

Iron Obes Op Minnesota.

nor jaspilyte. In the immediate vicinity are jasper nodules, indi- genous in the midst of the schist, red and purple, some of them five or ten feet long, appearing like quartzose aggregations in the midst of their native sediments, but at a little further south being white instead of purple. Subsequently a similar minute succes- sion beds of alternating jaspilyte and green schist was observed further west, on the southern slope of the "south ridge." - Hero are some interesting exhibitions of the relation of jaspilyte to the schist, some of them showing the minutest interstratification of the jaspilyte with the sericitio sedimentary schists, and others exhibiting the man- ner in which isolated, trans- ported masses of thejaspi- lyte are surrounded uncon- f or m ably by -a chlorite schist. Of the former the following sketch was made (figure 7):

The area here represented can be seen to extend with tbe strike a distance of twelve feet, when the characters fade out gradu- ally by the loss of the siliceous element, the rook becoming en- tirely schist. Before this takes place the siliceous bands are interrupted, and some nodnles and accretions appear in place of the continuous sheets of

The quartzytefor jaspilyte) on the weathered surface is light gray, but on the freshly broken edges shows the jaspilitic colors. The schist is fine and evenly la- minated, in its alternations with the quartzyte, and with itself, not being disturbed by coarse sediments, or by faults or con- tortions. This is one of the most perfect illustrations that has been seen of the manner of transition from the jaspilyte to the schists. Indeed there is here no general transition, eiuoe nothing but green schists exist on either side of it for a distance of eight or ten feet, as far as tbe rook is exposed. The diagram shows rather

54 Bulletin No. Vi.

that the jaspilyte is in thin interstratified sheets within the sericitio schists. The sketch does not show, and cannot be made to, all the fine in terminations and gradations between the two, since the schists themselves become arena- ceous and gradually lose their green tint, becoming gray, then white, then par- pie, when broken, and requiring the designation jaspilyte. The thickest dis- tinct lamina seen here is about one inch, and the thinnest is a mere film and become lost in the schist. This is a true inberstratifioation due to sedimen- tation, visible both in the jaspilyte and in the schist. The strike is ten de- grees south of west, and the bedding is vertical, or dips at an angle to- ward the north. No drawing can do justice to the minute mingling of sil- ica bands with schist bands. The continuous lines indicate silica sheets, and the broken lines indicate the schist The black irregular patches are intended to show chemically deposited vitreous silica. The distance across the bed- ding is three and one-half feet, and is exaggerated in respect to the 1"igrii actually included in the sketch.

Another observation of a mingling of the sericitic element with the siliceous was made in the summer of 1889, indicating still different circumstances. In the last case it will be noticed that there is an interlamination of the two in distinct, thin laminsa, and that the prevailing element is the green schist, but in this case it was observed on a general glaciated jaspilyte surface, where the prevailing element was quartz, that green schist layers, contorted in much the same manner as the associated sheets of colored jaspilyte, were introduced. This was seen on the northward slope of the "north ridge", north from the Tower mine (now known as openings 7, 8 and 9). Here in the midst of the general jasper contortions (see plate n.) is a belt which is markedly dif- ferent from the rest, being greenish, and was at once taken for a schist bed. It was carefully sketched, with its associated jaspilyte bands, but on close inspection it was found to be composed not entirely of the element of the green schist, but had a liberal per- cent of the fine silica, indeed was so siliceous that were it not for the contrast it presents with the smooth, hard jaspilyte on either side it would hardly be considered green schist. It faes generally, in other beds, into a softer (yet siliceous) light- green schist which cannot be mistaken for anything else. It appears hence that in the same greenish schist, embraced within this jaspilyte mass, which elsewhere embraces the jaspilyte masses* there is a minute indiscriminate mixture of the elements which generally appear as contrasted constituents of the rocks of the country. It appears further that the schist layers were formed before the contortion, and participated in it, and were not differ- ently introduced so as to be independent of it. This green schist here contorted with the jaspilyte is represented by rock No. 1571,,

Iron Ores Of Minnesota. 56

(see thin section, plate ix). This jaspilyte surface is illustrated

by plate n.

Explanation of Plate II. ' Crumpled jaspilyte surface on the north slope of the North Ridge, near the Tower mine or openings numbered 7, 8 and 9. At the left of the plate the hammer-heads lie in two belts, or laminsB of green schist, as described in the text, crumpled with the jaspilyte and hematite. B*ing weathered ont more rapidly they have caused crooked furrows which reveal their nature and their relation to the jaspilyte on either side. The broken hematite band which is illustrated in figure 8 occurred in the midst of this jaspilyte surface at the right of this plate.

On the north side of Otter Track lake are similar transitions be- tween the materials of the jaspilyte and of the schist. They were described in the seventeenth annual report (p. 114). They are on a much larger scale. Sometimes the rock itself seems to fade into jasper, and to become ferruginous and banded. At other times the rock is quite massive in appearance and has an abrupt contact with the enclosed masses of jaspilyte. This also illustrates the fact that in the midst of the forming Keewatin schists, there were gentle forces that operated to mix the iron- jasper elements mi- nutely, and that contemporaneously there were violent forces that tore up and shattered the beds lately formed and mixed the an- gular fragments with the next formed schists.

Still another observation was made near Tower, on the south slope of the "south ridge", by which a very different mingling of these rocks was revealed. Here the two are not inter-laminated, nor intimately blended as in the last, constituting a rock interme- diate in character between the schists and the jaspilyte, nor yet mingled in the form of a breccia. That is, they have not the as- pect of a breccia. The surface of the rock at this place was photographed in 1886 (see fifteenth report, p. 229, foot note), and the photograph is reproduced by half-tone electrotype in plae in.

Explanation of Plate III.

This plate illustrates the surface of the rock (nearly horizontal) at a point about fifteen rods east of the place illustrated by figure 7. The siliceous parts are not in the form of parallel bands running in the direction of a sedimentary structure and forming a part of it, such as seen in figure 7, but the silica is in fine lumps, drawn out in the direction of the schistosity, some of the lumps being not more than a sixteenth of an inch in thickness, or a mere film, and some of them being an inch or two. There is in some places (not shown on the plate) a fine threadlike interlaced mesh of roughness caused by the more enduring silica ingredient standing up on the surface of the weathered schists. In the interstices of the meeh is the schist, some of the areas of the softer rock being inclosed, or nearlv inclosed, by the harder, but for the most prevailing over the harder in one direction, and giving place to more and more of the siliceous ingredient in the other. There is visible here

56 Bulletin No. Vi.

no true sedimentary banding, bat the j as per o id silica is disseminated irre grnlarly through the schist. There is no graduation of the schist into the silica by varying amounts of fine silica in a soft green or grayish mud; but the silica, even in the smallest lumps, is pure t-ilica, and the schist does sot percepti- bly vary in its characters. In one direction, as the silica increases, it forms larger and larger lumps, so that some of them have the characters of jaspilyte, but without the parti-colored banding. Instead of banding the colors are in blotche.. Thi6 is seen at the right of the plate in several lenticular masses of jaspilyte. Still further in the same direction, as the jaspilyte mnrmoo increase in size, so as to constitute the most of the rock, they are somewhat banded by alternating colors, and sometimes the banding is transverse to the schistose structure.

It would seem, from the facts mentioned in the description of plate in, that this lumpy silica is due to the dissemination through the green schist, of small pebbles and larger masses of jaspilyte which had before been formed as jaspilyte and had received its banding, while the schist was being accumulated rapidly. Origin- ally they may have been angular or rounded. It is evident that their shapes now are accommodated to the dominant direction of the schistosity, and they are so intimately inter-locked with the schist that they appear to have been contemporaneously formed where they now lie as constituent results of the schisUforming force. But these grains and masses are foreign to the schist. They do not mingle with it, though so intimately mixed with it. It is possible that at other points, in the vicinity further to the left, or even at a time cotemporary with the formation of this, these pieces of jaspilyte were reduced by sedimentary selection so fine that they are comparable with the minutest siliceous grains of the jaspilyte, and in that case might produce the sedimentary structure seen in figure 7, but no such transition has been observed. We are left to infer, therefore, that this plate represents a breccia, or a conglomerate, which may have been like those represented by figures 3 and 4, or some modification of them, and that by pressure and shearing the entire granular arrangement has been changed, every piece having been stretched into greater dimension in a direction parallel with the schistose structure. While this elonga- tion is stamped on the larger masses (not shown in the plate) their original shapes have been better preserved, and their internal structure is still evident. It is the smaller pebbles that are most distorted by this shearing.

Other physical peculiarities might be mentioned. One of the most important is the separation of some of the layers from a gen- eral jaspilyte mass in an oblique direction and their running trans- versely to the schists in a manner somewhat resembling a dike of trap rock. Such appearances are not common. Indeed, but one or

Iron Ores Of Minnesota. 57

two are known at Tower. They seem to be more common at Mar* quette. Such branches have been supposed to indicate an erup- tive origin for the jaspilyte, but it is necessary to explain them in some other way, consistent with many facts that demand the pres- ence and active participation of oceanic water in the process of formation of the jaspilyte. The reader is referred to the fifteenth annual report for a discussion of the eruptive hypothesis and a statement of objections to it, and for an explanation of the dike- like appearances of some of the jaspilyte bodies.* These objec- tions are summarized in another part of this bulletin. In brief, it is only necessary to say at this place that these branches from the ore bodies are supposed to be caused by the crumpling and break- ing and squeezing of the entire rock structure of the country, by which some of the thinner sheets have been " buckled out" and thrust laterally among the enclosing green schist. Such angular displacements are seen on a grand scale among the argillytes and graywackes of the region, at some points on the south shore of Vermilion lake, on sec. 20, 62-15. Plate iv represents, by repro- duced photography, the appearance of the so-called dike which is discussed in the fifteenth report. This view was taken in 1886 be- fore the face of the bluff had been hid by the working which has since filled up that part of the mine.

Explanation of Plate IV.

The " dike " is seen ascending perpendicularly across the face of the bluff, near the center of the view. Its width is about two feet, varying to four feet. It was visible formerly continuously from the surface of the ground downward to the first level, about 45 feet, and, passing under the ascending railroad track, could be seen crossing the schists in the same manner, and in the same direction, in the next lower level, about 35 feet deeper. The ore of which it is composed is not of first quality, but too siliceous. It show9 distinctly the banding characteristic of jaspilyte. It is jointed horizontally as well as per- pendicularly.

The surrounding schists are charged with iron peroxide and are entirely destitute of the usual fine schistose structure. They are coarse-grained, finely jointed near the "dike," but massive or irregularly cut into large blocks by joints, at more distant points. In close proximity to the " dike " they are much confused by close and irregular fissure planes.

Again, the curious, minute fracturing and repeated faulting of some of the individual layers of the banded jaspilyte, while those adjacent are intact, is worthy of note. One such is illustrated by the following sketch, figure 8, which represents the minute fault- ing of a band of brown jasper embraced in an unbroken band of hematite, drawn from nature near the opening No. 9, on the north

♦Fifteenth Report Minnesota Survey, pp. 223-247.

ba BULLETIN NO. TI.

elope of the north ridge at Tower. This is included in the spaco represented by Plate II.

Explanation of Figurt 8. No. 1. Narrow belt of pure hematite, about inch wide, embraced in bard jsapilyie, running about four- teen inches, so far as sketched, one of many similar sheets near adjaosnt

No. 2. Broken and faulted brown jasper sheet, embraced entire!}' within the hematite of No. 1, the parte having once evidently formed a connected layer. No. 8. Semichalcedonic quarts velnleta, apparently the original cement for the fragments of the brown jasper.

The width is exaggerated.

It appears that the jasper layer was fractured aw represented, and cemented by silica (No. 8), and that uubeeqnently It was faulted generally at the same places where it was before fractured, but that bo me of the original fractures ware not faulted. After the fanlling the whole was embraced in a later deposition of pure hemstite, one of the ribbons that mark the large jaspilyte mass exposed here. The reader may compare Figure 60. p. 378, Fifteenth report.

It has already been shown that many pieces of the jaspilyte varying in size from the smallest appreciable fragment to large bould- ers, and even to pieces that seem not to have been moved very much from their nat ve places, are disseminated through the green schist Several were noted specially, and sketched in the summer of 1889, and such are illustrated in the eighteenth annual report.

In the highest of the tunnels of the Tower mine, which discharge southward, and also the most westerly, and at the southern end, is a north-and-south rock-cut, which seems to transect that series of thin layers of alter- nating jaspilyte and schist which occurs south of the Stone mine, at the railroad cat, already alluded to. This tunnel cuts across the bedding and the schistosity, and there- fore the phenomena displayed here are the complement of those described at the other cut, which goes nearly parallel with the Btrike. Several important physical structures are emphasized

Fig. S.

Iron Ores Of Minnesota. 59

here by the appearances, that can easily be inspected on the face of the cut. (Compare the 18th annual report).

L The jaspilyte is contained in the schist in lenticular masses, and in thin, interleaved, vanishing sheets that have thin, sharp edges upward and downward. This is most manifest in innumer- able instances here within the horizontal space of thirty feet.

2. The jaspilyte is contained in similar masses that terminate east-and-west in the schist.

3. In the space of 22 feet, north and south along the face of this cut, can be counted 36 jaspilyte layers, varying in thickness from J to 24 inches, all of them having at least six inches extent up and down, the rest of the rock being green schist, or jaspilitic red schist (or "shale" similar to rock 1547). Besides these there are some indefinite graywacken layers containing rounded pieces of jaspilyte as pebbles.

4. On the east side of the cut is seen the manner of termina- tion of one of the larger lenticules of jaspilyte, in the midst of the schist, the exposed terminal end appearing unbroken near the track, though broken off at the top by the work of making the cut- ting. The shape of this western termination is represented by the figure below (Fig. 9), which shows a section across the lentioule north and south.

5. Within two inches of this large mass, sketched above, was a smaller, apparently concretionary mass of as- pilyte, about 18 inches in its greater (perpendicular) diameter, appearing on the face of the cut to be entirely iv / I"1* surrounded by the green schist, and

separate from the larger lenticule. In order to ascertain whether it was con- nected with the foregoing large mass, by means of a crow-bar it was dis- lodged entire and fell to the ground. It left a continuous concave socket, a the exact imprint of itself, and was coated and smoothed over its whole exterior in the same manner as the larger one, and was wholly independent and separate from it It is numbered 1568. It is sharper, in cross-section, at the upper end than at the lower, and while about 18 inches in perpen- dicular diameter, it is only four and a half inches thick north and south, and eight inches wide(i. c, E and W.) Several small

62 Bulletin No. Vi.

exploration, the drilling having been in the same rock when it ceased, at the depth of 1,001 feet, bat having umpected a sample of this, sent by Mr. Wilcox, it proves to be a soft greenstone, with coarse folia of chlorite, and without apparent free quartz.

North of the summit of the north ridge, yet within the main bulk of the ridge, the drill revealed a large body of fine ore which has since been entered upon by the mining company, and is pro- ducing largely. At numerous places, and at various levels in the drill holes, beds of ore were reached which had, so far as known* no representation at the surface. In the same way beds of jas- pilyte, more or less associated with ore, and some without any ore worthy of mention,- were passed through. It appears therefore that, while the ore-bodies are frequently associated with the green schist, in its most massive conditions, they are not placed in it in any recognizable order. They are grouped in greater frequency along some belts. They have the form of lenses, running to edges and vanishing in all directions. The belt of iron-bearing green schist is very wide at, and south from, Tower, and it is possible that at greater depths the bodies of merchantable ore will be found to have shifted their geographic position with respect to the "ridges'9 in which they are now mined, and may be at some distance south from Tower. The present surface topography coincides with the comparative resistance to erosion presented by the different rooks. The ridges are ridges because they are firmer and harder. The swampy spots are low because they are, at the surface, underlain by the softer rocks. But had the destructive erosions of the past, and especially that of the Glacial epoch, been carried on to the depth of 500 feet further, or ceased 500 feet higher up, there is no doubt that the present North ridge would have presented a very different aspect, and it is quite likely that it would not have an ex- istence at all in its present latitude. It is probable that the jas- pilyte masses which give it existence would have been either whol- ly destroyed, and that in their geographic places soft green schist strata would prevail, or that they would be still buried hundreds of feet below the natural surface. But it is equally probable, had erosion ceased sooner, or had it been carried further, other ridges would have been protruded similarly above the natural surface, carrying equally remarkable bodies of hematite.

It has been stated that there is in general, no recognizable stratigraphic order in the ore bodies, but that they are placed helter-skelter in the green schists, only being larger and more abundant along certain belts of country characterized by such schists. Yet in the practical mining of the ores at Tower, Capt.

Iron Ores Of Minnesota. 63

B. J. Williams is of the opinion that, within certain limits, he has recognized a general principle of what he calls "right-handed throw." That is, when in course of mining an ore body ceases toward the east or west, along the strike, it is likely to recur again toward the right obliquely from where it disappeared, if it exist at all. This rule he thinks has been sustained in a majority of in- stances that have come under his observation. As the general strike, as seen on the surface, ought to agree with this succession of lenses below the surface if it be true, such a law ought to be expressed in the succession of lenses at the surface, but it has not been observed. It would indicate that toward the east the ore bodies are gradually crowding toward the south, relative to the body of the green schist,and toward the west that they are crowding toward the north. If this principal be true it has one marked exception at Tower, viz: The north ridge, which is a large lens of ore and jaspilyte, lies east of the meridian of the south ridge, yet it illus- trates a left-handed throw, since it is further to the left obliquely from the east end of the south ridge.

There is, however, a well-substantiated instance of vertical tran- sition on a large scale from worthless jaspilyte rock to merchanta- ble ore. This was in the Htone mine (No. 4), and a photograph of the spot is poorly reproduced in Plate vi. In the plate a column of jaspilyte is seen standing near the center of the plate rising to the surface. This was left because it was not ore, but on the sec- ond level, about 50 feet lower, it was found that this column, in the regular line of its strike downward, afforded good ore. At the bottom of the plate, in the foreground, in the original, a mining scene is shown (at the crosses XX), but this is not brought out in the plate. This change is due to a variation in the rock as an ore- carrier, and not to a bodily transition of the ore and rock to a dif- ferent plane. In the same plate, further to the right, another re- markable vertical transition is shown. This change is more sud- den. The overlying jasper roof, which rises to the natural surface, was found to cover a large mass of valuable ore, which in the photo is shown to have been removed. The same is illustrated by figure 11 below. The same transition from ore to jasper has been noted at Marquette by Prof. R. Pumpelly (Tenth Census, vol.

xv, p. 8).

Figure 11 shows the appearance of the west end of the one mine (Shaft No. 3), as it was in July, 1889, (also shown imperfectly by photo-plate No. 6). The jaspilyte mass which presented at the surface a broad exposure (N. and S.) suddenly, at about 20 feet below ti*e surface, narrows to less than one half the width it has at the surface and in its place is found a large body of good ore. Between this ore and the overlying jaspilyte there is a sudden passage,

Bulletin No. Vi.

au if there bad been a bodily displacement

t no raoh midden transition

Fig. 11.

appeared between the jaspilyte at A and the ore at B. In the drawing (fig. 11) another Feature ia seen which could not be brought out in tbe photo, viz: a wedge-shaped mass ol greenish soap rock, like that in the walls, is found to protrude upward into the ore. This bad not been sufficiently uncovered to reveal its size nor its shape any further.

Other alternations were seen in tbe W. Ely mine (No. 6). It ia frequently noticed that the soap rock divides ore from jas- per, or ore from ore indiscriminately, and hence ie no argument against ore and jasper being of similar and cotemporaneous or- igin.

Fig. 12 shows the aafe end of the W. Ely mine (No. 6) in July, 1889.

Fig. 12. E&at End of tbe W. Ely Mine (No.

Ibon Obes Of Minnesota. 65

Both vails are in soap rock, bat the north wall hIso bas some jasper. The figure shows an irregular, transverse, but upwardly flexed, series of strata UK/ consisting of jasper, ore and

schist, or soap rook. It ma; be presumed that these strata are the aame ss seen in Fig. 1, which shows the east end of this mine as it looked in July, 1886. The quarrying in this mine has followed tbe strata continuously, and between 1886 and 1889 their position changed from that shown in Fig. 1 to that shown in Fig. 12.

At the Tower mine (pit No. 7), which has proba- bly furnished more first- class ore than any other

Fig. 13. th_

A ltd

(under ground) of — INo. 0) Lenses of Ore

tbeW. Ely Mln

at Vermilion lake, the ore body becomes narrow toward the east, and evidently gives oat in a downward direction. At least a drill which entered the hill on the sooth side struck the ore bed south of where it is now mined, and did not find it beneath its pres- ent outcrop. It is as if there were a horizontal fault as shown in figure 14.

Strips?

fj

Qrju.-1,

Fig. U. Perpendicular Section of the Ore Beds at the Tower Mine.

Some farther information may be gained of tbe shapes of the ore-bodies by examining the ground plans of some of the mines,

Bulletin No. Vl

J>Z

viz: Plate xn represents the plan of the No. 3 pit (old Stone

mine). Plate xin represents the same for the No. 5 pit (old

East Ely mine). By these it appears there is a slight downward

inclination toward the north. Plate xiv represents the plan of

the Pioneer mine at Sly. It cannot be ascertained by this that

there is a dip in any direction.

At Ely the Chandler mine ore lens has developed a curious

shape as the mining has progressed. This shape is illustrated by

Fig. 15.

The ore of the Chandler mine is a

fine Breccia from which thp original cement (perhaps siderite principally) has been removed. It lies loose in its place and can be mined cheaply. Diamond drills have cut the Chandler ore 300 feet from the surface. It is still crushed at that depth. Shaft No. 1 goes down 190 feet in the foot- wall of greenstone. The first level is 80 feet deep. The second is 60 feet deep, and the third is 60 feet below the second. At one place the ore bed is 245 feet wide, and it averages about 90 feet w ide for 800 feet length. The ore is very uniform in purity and per cent, of iron. Although the ore of this mine is crushed to the total depth to which it has been ex- plored, it glows more solid toward the walls, particularly toward the foot- wall (south). There are bands or streaks in it which show the same folded or contorted structure as that usually seen on the surface of an ex- posure of jaspilyte. The ore is quite open to the action of percolating wa- ter. Many faces of the angular frag- ments are covered with a shiny black deposit of limonite which if it were thicker would form grape ore. A Fig. is. shape of the chandler Ore white mineral, probably the same

Lens, Ely, as developed in August,

1889. as that described at lower, is seen

in seams in the ore and in the " paint rock." Streaks and beds

Cd

Z

Co

U

Co

Off

€

k

k

o

o

o

S-

o u

Vj

Cd

W

Z

H

Cu

o z

n fa

o

Iron Ores Of Xinne80Ta. 67

of varying thickness of "paint rock" are found all through the ore, running in nearly all directions, but usually in the general strike of the ore. There is no doubt about this ore being the eame as that at Tower. It has simply been crushed by pressure, flexure and movement There are many large lump9 of ore mingled with the smaller. Sometimes — in the east end of the mine particularly, and there only on the first level — the crushed ore is mixed with much jasper and rock, and is rather lean. The ore, however, be- comes better on the lower levels.

At Tower a similarly brecciated or crushed condition of the ore is occasionally met with. On the third level of pit No. 5 (East Ely ) is a stratum of such ore about three or four feet thick.

(2.) Mineral associations of the hematites of the Keewatin. — The mineralogy of the iron mines at Tower has not been carefully studied, and we cannot say yet what number of interesting ac- accompanying minerals may exist From the three main con- stituents, the green chlorite schist, the silica and the hematite of the jaspilyte, there is every reason to expect many combinations and modifications have been produced by the physical changes and chemical reactions that we are led to believe they have been subjected to, in the long history through which they have passed. The profound physical and chemi al changes, however, to which it is evident the rocks of the region have been subjected, took place mainly in Archean time, and ceased in primordial time and left the strata very nearly in the mineralogical and structural condi- tion which they now manifest There has been no later, wide- spread, metamorphosing action. There has been only the slight surface action of meteoric forces, penetrating to the depth of a few feet, not probably exceeding, since the Glacial epoch, even. in the permeable schists, 50 feet below the surface, and generally not ex- ceeding 10 feet. As Arcbean time left the rocks, substantially so they have remained, excepting only so far as they have been dis- integrated and degenerated by extraneous weathering and erosion which may have carried away several hundred feet from the sur- face.

It is evident, therefore, that the mineral species are of two kinds. (1) Such as are indigenous to the formation, and date from Arch- ean time; and (2) such as are of secondary and subsequent origin.

The indigenous minerals are essentially chlorite, musoovite, quartz (chalcedonic) and hematite, with orthoclase and plagioclase occasionally disseminated abundantly among the pressed and sub- crystalline schists. There are also variations in the schistfe to cal- careous, dolomitic (?) masses which are constituent parts of the

68 Bulletin No. Vi.

Archean rocks.* But, in the schists, the foliated minerals, musco- vite and chlorite, are those that give character and color to the bulk of the Keewatin. That these minerals date from Archean time is shown by a consideration of their behavior with respect to the structure and with respect to other minerals. They partici- pated in the upturning, folding and shearing action which every- where distinguishes the Keewatin, and that action was practically complete before the advent of the Taconic (Animike), for the structures that it caused are seen to pass in their perfect develop- ment beneath the unconformable strata of the Animike. These minerals do not fill fissure- veins formed since the hardening of the rocks, but they constitute rocks that were crowded together, when once plastic, so closely, and so kneaded upon themselves that the smallest cavity that may have existed has been filled, the shape- less foreign pieces have been drawn out into some uniformity of elongation by some great force that acted over many square miles, and the easily molded parts have been compelled to adjust them- selves to the forms of the rigid. Where the pressure and shearing was sufficient to produce plasticity, the green schists have become hard and sub-crystalline, and have taken on the role and the structures of igneous rock. Several instances of this have been recorded and fully described.f The resulting rock is massive, but when it has not been squeezed out of its place it shows on weath- ered surfaces the banding characteristic of sedimentary structure. When it has been displaced it mixes with the unplastic fragments of the original strata, filling their interstices and wrapping about them, and on solidifying taking a basaltic structure. It seems to be an imperfectly developed syenite, and indicates the probable origin of larger syenite masses and ranges such as that of the Giant's range. It is in these sub-crystalline masses that are seen imperfectly shaped crystals of orthoclase and of plagioclase.

The secondary minerals are such as have been produced by the decay or solution of the indigenous minerals and the redeposition, by mineral waters, of the chemical solutions in fissures, cavities and all interstices in the original rock*. The alteration products sometimes are abundant. They produce calcite, dolomite, pyrite, vitreous quartz, limonite, specular hematite and siderite. Calcite, limonite and dolomite seem to have been produced in some oases since the consolidation, by recent weathering, and are apparently increasing in amount. But pyrite, vitreous quartz, hematite and siderite are of older date. They are found in deep-seated breccias

♦Fifteenth Report, p. 371; Sixteenth Report, pp. 05, 316.

Fifteenth Report, pp. 267 (rock 868) ; 316 (rock 1, H.); 352-355 (rocks 000-905).

Iron Ores Of Minnesota. 69

and in fissure veins, and are due perhaps to disturbances that af- fected the Keewatin rocks after their consolidation and perhaps 'at the epoch of the Taoonic ( Animike). Pyrite, especially, seems to have been of very early date, since it occurs in some places in large quantities deep in the mines, and as bright cubic crystals(as on Stuntz island) in pure, white, chalcedonic pebbles which are involved with other boulders in the Keewatin agglomerates. Through its decomposition and the decay of chlorite and siderite, large deposits of limonite are produced.

Without attempting here to carry the distinction between the min- erals and ore masses any further than to separate between primary and secondary products, it will be sufficient to call attention to two epochs of brecciation that are exhibited by the jaspilyte, each of which must necessarily have its distinguishing mineral characters and associations. The first of these breccias was coeval with the production of the ore and jaspilyte. It has been referred to and illustrated (see figs. H and 8) in describing the structural characters of the ores, and is further represented by plate XI, which is from a photograph of hand-samples collected at Tower. This breccia is characterized by being re-cemented by materials like the rock brecciated, generally by chalcedonic silica, the resulting mass being as firm as any part of the country rock. In several instances during the progress of the investigation of the ore-bearing rocks of Minnesota some puzzling and apparently anomalous occurrences of chalcedonic silica in the form of veins have been noticed. One is mentioned south of ]?all lake,* where veins of chalcedonic quartz were seen cementing a breccia of jaspilyte. In 1888 other samples were seen of the same structure, some on the South ridge, near the Lee mine, and some on Chester peak. These are referred to in the eighteenth annual report, pp. 28-35 . In the light of further study, the result of which is given above, these occurrences are no longer problematical. It has been seen that a frequent brecciation co- temporary with the deposition of the jaspilyte is one of the characteristics of the ore and of the jaspilyte, the cementing material being produced by a recurrence of the same forces as produced the original strata, and necessarily causing it to enter and permanently fill all the cracks and cavities that might have been left after the brecciation. As to the origin of this chalcedonic silica, it is believed to have been a chemical precipitate from the oceanic waters of Keewatin time. That subject will be discussed in another part of this bulletin.

Another brecciation took place after the jaspilyte and ore and

Fifteenth annual report, p. 324. Book sample 1013; also p. 245.

70 Bulletin No. Vi.

foregoing breccia had been formed. Its cementing minerals are crystalline, and often quite coarse. They are hematite in bright tabular flakes, vitreous quartz, (sometimes in large crystals,) pyrite and siderite. These minerals, when coarsely crystalline, and pertaining to this period of fracture, are seen to fill fissures that cross the jaspilyte and ore masses in all directions. These later veins also cross the veins and breccias of the former brecciation. But no veins of chalcedonic silica cut these. This second brecci- ation gave origin to a set of secondary minerals, but, though the hematite that is of this age, and also the siderite, are valuable by reason of their purity, as ores, and sometimes by reason of their quantity, they cannot be considered an important portion of the Keewatio ores, and in no case should be considered as elements in the problem of the origin of the ores of the Eeewatin.

If now this be pushed still farther, and we inquire when this second brecciation took place, we have only scant data to reason from. A brecciation and cementation which so deeply affected a great formation — for it operated on the schists and slates of the Eeewatin no less than on the jaspilyte and ore — must be explained by resort to some force of wide extent and long duration. It must have been of the nature of the earthquake and the volcano, and it must have operated in such proximity to the phenomena observed that its effects could be disseminated through the rooks concerned. These considerations point only to primordial time. The Taconic age, which followed next after the Eeewatin, repre- sented by the next overlying (Animike) rocks and the rocks of the Cupriferous, was agitated, in northern Minnesota by earthquake disturbance and volcanic phenomena. This is evinced not only by the nature and positions of the rocks of the Animike and the Cupri- ferous, but by the occurrence of many dikes of fresh trap-rock referable to that age, which cat across the strata of the Eeewatin, and which have been noted in all the Minnesota reports.* These later dikes vary in width from a few inches to fifty or one hundred feet, and they are found, in greater or less frequency, throughout all that part of the state underlain by the Eeewatin, and are not uncommon in the rocks of the Vermilion and the Laurentian. There is no other known adequate cause for such a fracturing of the older rocks as is seen in this second brecciation. Later periods of disturbance, fracture and upheaval are known in other parts of the country, some that followed the Trenton, some that followed the Carboniferous, and some that occurred during and after

♦Dr. A. C. Lawson has suggested that some of the eruptive rock of the Rainy lake region dates from the age of the Cupriferous.

Ibon Ores Of Minnesota. 71

Mesozoic time. Bat the loci of all these, so far as known, are more remote. lb is more reasonable to invoke a cause that is near at hand, when it is sufficient, than to seek for a more distant one. Therefore we may, for the present, refer the date of this second brecciation to that cause which lies nearest, and place it in primor- dial time.

It will be necessary to remark, in conclusion, in relation to the minerals that are found associated with the Keewatin ores, that a tertiary condition of the ore is found, in considerable quantities, sometimes, and affording merchantable products. It is limonite. This is derived very largely from a change in the pyrite and the siderite of the second brecciation, but of course augmented by any process of decay that may be now going on in any of the original ferruginous minerals. This is a natural effect of exposure to atmospheric forces, and while it may have been in progress during all post-primordial time, it is certainly in progress at the present time. Its earlier products were removed by the glacial abrasion, and those that now exist may be referred reasonably to post- glacial time. This limonite fills or partly fills some large cavities and is frequently found lining smaller ones wilh its botryoidal and stalactitic forms.

(S. ) Microscopic Characters of the Jaspilyte.

Plate VIII.

As the green schist embraces the jaspilyte, but very rarely shows a graduation into it, on the contrary the jaspilyte contains the iron ore and continually shows graduation into it. It became therefore, one of the interesting and important problems of this investigation to learn the origin of the jaspilyte. The method of origin of the silica, which constitutes the great bulk of the jaspilyte, was found to be inseparably bound up with that of the hematite. Numerous facts and considerations based on a careful examination of the physical relations of the jaspilyte to the ore and to the enclosing schist, with illustrations, have been given pointing to the origin of the iron and the silica from chemical precipitation from the oceanic waters of Keewatin time. It was necessary that every light possi- ble that could be thrown upon this inquiry, whether from chemis- try or microscopy, should be brought to bear on the problem.

It was seen at once that chemical analysis of the jaspilyte, as such, would be of no avail, since the rock is seen to vary, micro- scopically, from pure silica to pure hematite, a thousand times, and that all degrees of predominance of one over the other could be selected. The analysis of the ores themselves was studied in order to ascertain the nature of the prevalent impurities, and their per-

72 Bulletin No. Yi.

centages compared with those of other ores. Many of these analy- ses are given beyond (under Quality of the Keewatin hematites) and the bearing of the presence of the different impurities in their different amounts, as compared with other ores is discussed in the chapter on the origin of the Keewatin ores.

The microscopic examination of the jaspilyte was directed specially to the question — Is there evidence, pro or con, as to the siliceous ingredient of the jaspilyte being the result of chemical precipitation in oceanic water? Dr. Hensoldt has carried on this examination in our laboratory, and with frequent personal conver- sation and discussion between us. Numerous thin sections and all the field specimens were available for the purpose. The result, which is given below in Dr. Hensoldt's language, confirms unequivo- cally, and establishes the chemical precipitation theory of the jas- pilyte.

There are three microscopic features which the minute grains of the jaspilyte present, which can be explained only on the supposi- tion that the silica was chemically precipitated, and one of these indicates its precipitation in oceanic water. They are well described

below:

Jaspilyte.

Bock 867.— The hand specimen from which this section was prepared is composed of layers of a dense, whitish silica, alternat- ing with layers of hematite, which average an inch in thickness. The lines of contact are sharp and distinct and no trace of grad- ual transition is anywhere observable. The jaspilyte layers are, practically, homogeneous throughout, but the hematite strata exhibit numerous cracks and fissures, which are filled with the same siliceous material which constitutes the jaspilyte. The sig- nificance of this feature will be shown later on.

Under the microscope the section of jaspilyte reveals a structure which might be termed "crypto- crystalline," but which differs completely from that of any ordinary massive or fragment al quartz-rock. Instead of angular or rounded grains cemented by an interstitial substance, as in sandstone, or "vitrified" by pressure, partial fusion or siliceous infiltration, we have here silica in a finely divided condition, such as can only be accounted for by chemical precipitation from a saturated solution. Under a magnifi- cation of about 60 diameters the section presents the curious "mottled" structure which characterizes certain siliceous deposits, such as the well known novaculyte of Hot Springs, Ark., and which has never yet been observed in crystallized quartz. It would seem as if an immense number of siliceous particles —

Oool.andNat.HlsI. Sur Mi

Bulletin No. 8. PI. VII.

Ikon Ores Of Minnesota. 73

neither partaking of the character of crystals, granules or angular fragments — had been accumulated and cemented, not by an inter- stitial paste, but by superincumbent pressure. Many of the siliceous particles are colorless or nearly so, while others are more or less clouded by an opaque dust-like substance, probably mug- netite. At first it would appear as if each constituent granule W3 will retain this term for the sake of convenience) had been part of an originally homogeneous matrix of amorphous silica, such as flint or jasper, which through heat or pressure became partly disintegrated and traversed by an elaborate network of minute cracks. Thus the granules would have resulted from a mere sub- division of the homogeneous matrix by means of ft? sure-cleavage. But if we examine our section with a "half-inch" objective we are startled to observe that mpny, if not most of the granules show a remarkable uniformity in size as well as outline. Instead of irreg- ularly bounded fragments of the most varying dimensions, such as we would naturally expect in fissure-cleavage, we behold particles of nearly uniform size and more or less hexagonal boundaries. In many instances the hexagonal outlines are of extreme regularity (see plate vn); in others considerable distortion is noticeable, but as a general rule they are persistently manifested, even in the closely joined or welded portions of the mass.

That these siliceous particles are not sand* grains, as one would be tempted to infer from their appearance so far, can be clearly proved in two ways, viz:

L By their behaviour in polarized light.

2. By the absence of fluid enclosures, which invariably occur in crystallized silica.

If the particles were "crystallized sand grains," viz., sand-grains transformed into symmetrical crystals by a secondary deposition of silica, or if they were fragments of an originally crystallized or crystalline quartz (whether the constituent of some ancient granite or otherwise) then each individual granule would only show one uniform tint between crossed nicols, viz., either blue or yellow, un- less the granule happened to be cut at right angles to the optic axis, in which case it would only give four extinctions. In this jaspilyte, however, each granule invariably exhibits several colors, which, on rotating the lower nicol do not change in the normal order of crystallized quartz but seem to turn around a central point, precisely as we see it in chalcedonies, jaspers, agates and other amorphous silica. In the novaculyte of Hot Springs, which is a chemical precipitate of silica, we observe the same phenomenon

The second line of proof is even more conclusive than the first

74 Bulletin No. Vi.

No crystallized quartz has yet been discovered in which fluid-en- closures are not more or less abundant. Minute cavities, contain- ing water, saline solutions, hydro-carbons or carbon dioxide are formed even in the clearest rock-crystal and occur in millions in the quartz of all granites. ''Smoky" quartz is full of them and the whitish color of the so-called milky quartz is entirely due to the presence of myriads of cavities. Now the quartz granules of this jaspilyte are entirely free from fluid lacunae of any sort and even the most careful search, under high powers of magnification, will not reveal a single cavity. We also look in vain for fluid-cavities in agates, chalcedonies, jaspers and the novaculyte already referred to; thus we cannot be far wrong in attributing the formation of the granules of the jaspilyte to a non- crystalline source.

But then, if these granules are amorphous silica, how can we ac- count for their hexagonal outlines? There we are at once con- fronted by a fact which, if correctly interpreted will furnish a key to the entire mystery of this jaspilyte formation. In the writer's opinion there can be but one answer to this question. The silica which now constitutes the jaspilyte was chemically precipitated from a solution. What the character of this solution was, will per- haps never be even approximately determined, and is immaterial for the purpose of the present inquiry. The silica may have been contained in the heated waters of an ocean, charged with hydro- chloric, sulphuric and other acids, an ocean such as this globe will never know again. Where the silica originally came from will also remain a subject for speculation. Enough that it was precip- itated, and moreover in a gelatinous condition, viz , in the shape of minute globules. There are strong grounds for believing that these globules were perfectly round or spherical, and that their ac- cumulation was a slow and protracted one. Soft gelatinous globes or spheres composed of any yielding or pliant substance, when superposed or otherwise compressed will invariably assume hexa- gonal outlines, as can be easily verified by experiment.

Thus whatever line of inquiry we may follow — and it must be borne in mind that the methods at our command, in this instance, are necessarily restricted — we are driven to the same conclusion, viz., that the silica of the jaspilyte is a chemical precipitate; and in the writer's opinion this point is clearly established.

In reference to the origin to the hematite layers, which are so re- gularly interstratified with the jaspilyte deposits, the microscope, for obvious reasons, can give us no material assistance. But reasoning from all the data in our possession, there cannot be the shadow of a doubt that their precipitation took place in precisely the same

Iron Obes Of Minnesota. 75

manner which characterized the formation of the jaspilyte. The silica of the latter and the iron of the former were contemporan- eous in their origin and the order of their deposition was solely determined by gravity. Let us assume that both the silica and hematite were once the constituents of a basic lava or volcanic ash, ejected by one or more submari je volcanoes in pre-Huronian times. That most, if not all volcanic outbursts in that remote period were submarine cannot well be doubted, as we have no evidence of the existence of dry land previous to the Laurentian age. The earth's crust was considerably thinner then and disturbances of a volcanic nature must have been of far more frequent occurrence than at the present day. It is now very generally admitted that the iron which we find on or near the surface — no matter in what form — was originally derived from deeper-seated regions in the interior of our planet and was brought up by volcanic agency, as a constituent of lavas and similar eruptive products. All eruptive rocks, wheth- er basic or acid, contain iron in some form, usually as magnetite, though titaniferous iron and chromite are also extremely abund- ant, and the Ovifak basalt, which is the most basic of all known rocks, contains an enormous quantity of metallic iron. Then there are the iron silicates, such as augite and olivine, of which all basic lavas are very largely composed. Let such a lava come in contact with the heated waters of an ocean, heavily charged with hydrochloric, sulphuric and other acids, such as we know must have been the condition of the ocean for ages in the earlier history of our planet (unless we abandon the entire con- densation-hypothesis) and a comparatively rapid and complete solution of the components of our basic lava, or volcanic ash, was unavoidable. The iron of the magnetite, being easily soluble in H CI, was first deposited in the form of a soft mud, by reason of its greater gravity, to be followed by the silica, which would prob- ably occupy a much longer period for its complete precipitation. There are grounds for believing that the first deposition of gelat- inous silica did not take place till long after the formation of the hematite stratum and that the latter was repeatedly disturbed by upheavals and subsidences on a minor scale, causing numerous local distortions and cracks in the dense hematite mud which were subsequently filled by the gelatinous silica.

What became of the calcium and magnesium contained in the pyroxenicand feldspathic constituents of the original basalt, might well be urged in objection to our hypothesis, but a moment's re- flection will show that their absence is really easier to account for than would have been their presence in the rock under examina-

76 Bulletin No. Vl

tion. These elements, by reason of their lesser gravity, were kept much longer in solution by the water, which, moreover, was of far greater density than any of onr present oceanic or lacustrine waters; thus they could be easily drained off by currents and deposited as magnesium and calciam carbonates — dolomytes, marbles, lime- stones, calcite — in localities more or less remote.

Periods of comparative quiescence must have succeeded each volcanic outburst, as evinced by the regularity and uniformity of the inlerstratification of the hematite and jaspilyte, and we must necessarily assume as many separate eruptions or successive lava- flows as we have layers of amorphous silica alternating with iron ore.

Hand-specimen 867, which has furnished the material of our section of jaspilyte, has been selected as very typical of its class and as fairly illustrating the points and problems here discussed. The microscopical structure of the numerous samples of jaspilyte ex- amined by the writer, some of which were from localities many miles apart while others had been found in close proximity to each other, was practically identical so far as the essential features are concerned. In some instances the siliceous granules had been 60 firmly compressed or welded together that their individual outlines were more or less obliterated, so that the entire mass presented the dense, compact appearance of most of the Hot Springs novacu- lytes. In others the structure almost approached that of certain fine-grained sandstones, so clear and distinct are the component granules.

Rock 1568. — A massive reddish-gray jaspilyte, almost identical in its microscopical structure with that described under 867. The component granules are, however, exceedingly small, but with a good "quarter" objective their outlines can be clearly distinguished in the section, and we observe many symmetrical hexagons, as in the other varieties of this remarkable rock.

The sections of jaspilyte which are illustrated in plate vn, show- ing the shapes and deposition of the siliceous grains, and to a con- siderable extent also those seen in plate viii, showing the colora- tion of jaspilyte between crossed nicols, are affected by the con- fused "aggregate" polarization resulting from the overlapping of the individual grains. Sometimes in making the drawing of these sections it is found difficult to distinguish and outline the shapes of the separate grains. By changing the focal distance of the microscope, by a very small movement of the mic- rometer adjustment, not only do the shapes which were before dim or which faded out entirely, become susceptible of delineation still

Iron Ores Op Minnesota. 77

further, but other angular outlines which were at first indistinct or only seen along one side or angle, not belonging to the same silica grain as those already drawn, make their appearance more system- atically, and by still further moving the micrometer adjustment, there comes into view a new set of more or less hexagonal grains. Of course the thinner the section the less there is of this inter- ference, but in none of the sections made by us has this difficulty been found wanting. It is most pronounced in the preparation of the colored figures on plate vin, because some of the shapely grains seen in ordinary light become divided, between crossed nicols, into several differently colored parts due to the refraction of the slightly underlying or overlying grains.

As explained in the description of the structural relations of the jaspilyte, there are some places where the jaspilitic element, i. e., the chalcedonic silica, is somewhat mingled, microscopically, with the element of the green schist Although the change from one to the other, as seen in the field, is usually quite abrupt, yet there is occasionally a mixing together of these elements in one stratum.

When we come to examine thetlhin sections we find that there is frequently a sparse microscopic dissemination of the elements of the green schist through the jaspilyte. The figures seen in plate vii were drawn from sections of jaspilyte that do not contain any of these foreign grains. No mention is made of them in Dr. Hen- soldt's descriptions, he having purposely confined his examination to those sections which furnished the problem of the origin of the jaspilyte without any entangling attendants, and hence to the pure chalcedony itself. In the section of rock No. 511 A (H), may be seen lying adjacent to the wavy, or somewhat ragged edge of the green schist, yet wholly within the jaspilyte, a few flakes and slen- der fibers of the green schist, and some projections of the schist, in the form of long fibers embraced among the silica grains. These fine detached parts are nearly colorless, whenever rotated between crossed nicols, particularly when they present some angularity, or outline that might be considered the result of some transform- tion in the crystalline structure. As they are followed into closer and closer proximity to the schist border they are multiplied in numbers and assume the usual green tint.

These fibers from the green schist should not be confounded with another colorless ingredient that is more abundantly scattered through the jaspilyte. This is in the form of microscopic grains and aggregates of grains. It is common in rock No. 511 A (H), but much more common in rock No. 1565, which is described mic- roscopically as a flinty, gray or dark-gray jaspilyte from the shaft

78 Bulletin No. Vl

at the Breitung mine (No. 12). These grains, which do not become fibers, although generally of irregular shape, yet have a tendency to rhombohedral outlines. Their nature is not definitely ascer- tained. They remain light even under complete rotation between crossed nicols. They show no dichroism, so far as observed. They may be dolomite, and were apparently chemically precipitated in the same manner as the silica. They cause the opaque whitish- gray color of the rock. In the darkest portions of the rock may be seen, along with pyrite, a black opacite which shows no definite forms, and may be carbonaceous. Fig. 2 on plate viii is drawn so as to exhibit these irregular transparent grains, as they appear in ordinary light, distributed throughout the section made from rock 1565, the siliceous grains of the jaspilyte, which made up the rest of the section, being disregarded.

Plate ix represents the appearance of rock 1571 in thin section. The upper portion (Fig. 1) shows its appearance in ordinary light, the green and darker green being chlorite scabs and fibers, and the uncolored part being quartz. In respect to the chlorite it may be sten easily that it is derived fromjoriginal hornblende grains, since in many instances there are remnants of hornblende still risible with its characteristic cleavages and polarization, one mineral showing a relation of transitional dependence on the other.

The lower portion, fc&rFig. 2;represents the same surface when placed between crossed nicols and under the Klein quartz plate. It is at once apparent that throughout the siliceous portion are numerous silica grains of larger size and more brilliant polari- zation than are usual in the sections of pure chulcedonic silica, although still the larger portion of the silica cannot be distin- guished from that characteristic of the jaspilyte. This greater coarseness shows that this greenish belt, embraced within the characteristic jaspilyte, was accumulated during a short interval of greater agitation, and one not favorable for the gentler deposition of the chemical precipitate.

Rock 511 A (H). — This rock furnishes a remarkable instance of the contact of utterly dissimilar masses. The hand-specimen is, in part, composed of parallel layers of ferruginous silica and mag- netite, followed by a soft ottrelite-schist of dark green color. The section is cut so as to include both formations and to show the line of contact, which is clear and sharp, without a trace of gradual transition. The filica of the ferruginous layers differs in no way from that of the jaspilyte, described under 867; we notice the same granular structure, the same polarization phenomena, the same absence of fluid-enclosures and the same prevalence of hex-

Iron Obes Of Minnesota. 79

agonal forme. In some places, however, the layer is traversed by veins of crystallized quartz, intersecting the jaspilyte almost at right angles to the plane of bedding. These veins doubtless rep- resent cracks and fissures, once existing in the stratum, which were filled with silica derived from a more recent source. The "vein- silica" contains numerous fluid-lacunae, and has a distinctly crys- talline structure.

If we examine the ottr elite- schist we find it to be almost exclu- sively composed of minute yellowish-green and bluish scales, which exhibit an intense pleochroism if tested with the polarizer only. That these scales are neither hornblende nor epidote is manifested by their softness, and of all the minerals of the chlorite group ottrelite alone is characterized by such strong dichroism. It can- not, for a moment, be doubted that this green schist was deposited under conditions totally different from those which prevailed dur- ing the formation of the jaspilyte, but what these conditions were and whether the two formations were separated by considerable intervals of time must remain a matter of speculation.

Bock 866. — A heavy, dark- red, or reddish-brown variety of fer- ruginous jaspilyte, interstratified with thin layers of magnetite, associated with hematite. Under the microscope the jaspilitic ground mass is found to be completely permeated, and almost obscured by dust-like grains of lpagnetite, as well as by larger crystals and aggregates of the same opaque mineral. In such por- tions of the field, however, as are sufficiently translucent the phe- nomena described under 867 and 511 A (H ) may be observed with- out difficulty, viz: crypto-crystalline structure, hexagonal outlines and circular polarization. As these, in the writer's opinion, are indicative of a chemical origin (as set forth in the description of 867) it must be presumed that the iron oxides, now present as magnetite and hematite in the rock under consideration, were contemporaneously precipitated. When we were deal- ing with bands of almost pure jaspilyte, alternating with layers of iron oxide (as in 867) we were justified in inferring a slow and gradual deposition during periods comparatively free from disturbance, when the silica and iron, dissolved in the water, could be eliminated in the order of their respective gravities. It is clear, however, that jaspilyte, so intimately associated with hematite and magnetite, as in 866, could not have been precipitated before or after the iron oxides, and a contemporaneous accumulation of such dissimilar deposits would imply the action of disturbing forces. Whatever may have been the nature of these forces, one thing is certain, viz: that their operation was confined to limited areas, as

80 Bulletin No. Ti.

we find strata of almost pure jaspilyte alternating with hematite in close proximity.

Mixed chalcedonic silica and green schist. It was shown, under the head of Structural features of the Keewatin Jiematites, that gen- erally the jaspilyte is distinct from the green rock in which it is embraced, but chat on close inspection the minute fine grains of silica, evidently of the same origin, are disseminated among the schists (see also the microscopic description of rock 1557), more widely than had been supposed. It was also shown by plate II, which is a reproduced photograph of a jaspilyte surface, and by figure 7, p. 36, 18th annual report, that the element of the green schist is occasionally seen mingled with those beds which are, in general, distinctly composed of characteristic jaspilyte. One of these greenish jaspilyte layers afforded rock sample 1571. The inferences that spring from this association of these elements in the same layer are patent; (1) that the two substances, the green schist and the siliceous jaspilyte and the hematite, in their physical relations, are the product of practically identical forces, or the same force, acting on different objects; (2) that after the formation of some of the narrow bands they were disrupted and contorted before the formation of the next succeeding bands; and (3) that there was usually a complete cessation of the deposition of the siliceous jaspilyte when the materials of the green schist were accumulating, and vice versa, but that occasionally, as illus- trated in these greenish jaspilitic layers, the two substances were deposited simultaneously.

Any theory that will satisfactorily account for the origin of the Keewatin ores must allow for these inferences from the structure, and from this microscopic association, at the same time that it plausibly accounts for the origination of the elements of which the jaspilyte and the green schist consist.

The section described below has a general greenish tint Mac- roscopically, when fresh, and freshly broken, the rock appears like a fine dense diabase, the fine silica grains not being apparent to the eye. It was described by Dr. Hensoldt without his knowing the physical relations which the rock from which it came, bore to the stratigraphy of the region.

Rock 1571. — Plate ix., quartziferous chlorite-schist. This is a fine grained, dark greenish-gray rock, composed of chlorite, bio tite, magnetite and quartz. The chlorite predominates and appears to be very evenly distributed in the different layers, which, however present various degrees of comminution. Most of the chlorite oc- curs in irregular patches, composed of minute scales or fibres, but

Iron Ores Of Minnesota 81

granular masses, of an apparently homogeneous character, are like- wise abundant There are grounds for believing that this chlorite has resulted from a decomposition of biotite, as most of the gran- ular masses show a distinct pleochroism, and we also observe biotite scales in all stages of alteration. Bat it is not improbable that the rock was originally a hornblende-schist, which became first transformed into a biotite and ultimately a chlorite-sohist. The magnetite, as usual, occurs in rounded grains, irregular aggre- gates and crystals, which rarely present symmetrical outlines, but innumerable dust-like particles are also visible in almost every part of the field. The interstitial quartz is neither crystallized nor amorphous, but presents the same curious features which we have described, in full, under 867. It is pellucid, and devoid of fluid- lacuDSB, and if we carefully examine one of the colorless patches, we find it to be an aggregate of minute granules which simulate hexagonal crystals and show circular polarization.

(4) Quality of the Keewatin hematites. Physically the Keewa- tin hematites are hard, and they require to be blasted. That is their usual condition; at Ely, however, in the Chandler mine, while the ore itself is hard, it is in fragments and can be mined with much less blasting. Indeed, in some cases it is excavated and hoisted without any blasting. This fragmentary condition seems to be due to a former brecciation recemented by siderite, from which the siderite has subsequently been removed. This is accord- ant with the fact that in the neighborhood of Ely have been dis- covered apparently large deposits of limonite, the probable product of such removal of siderite.

Chemically the Keewatin hematites manifest certain character- istic peculiarities by which they differ from all ores of later date, and by which they can be distinguished from the ores of the Ta- oonic age. The elaborate methods of testing and assay of the ores practiced by the owners of the mines, are given in another part of this bulletin.* It is apparent that such thorough chemical exam- ination affords the best possible opportunity to become acquainted with the qualities of the ore. These examinations are duplicated, in nearly all cases, by the purchasers, or by the selling agents, or by the furnace men who use the ores. Such averages are pub- lished in the grade lifts of the principal dealers, and they pive permanent reputaton to the ores produced in all the mining districts of the country. A comparison of the Keewatin ores of Minnesota with those of the Taoonic (Huronian) of the south side of lake Superior, based on an examination of several thousand assays, in

under Mtthodi of mimjAing and analyzing.

82 Bulletin No. Yi.

1888, as published by Pickands, Mather and Co., shows that while the amount of silica and of phosphorus does not differ very much from that in the Taconic (Huronian) ores, in respect of other impa- rities there is a very important contrast. The latter ores contain about 300 per cent more manganese, about 400 per cent, more sul- phur, about 33 per cent more alumina, about 25 per cent less of magnesia, about 400 per cent, more lime, and about 400 per cent, more water.* It is not certain from what age of rocks some of these more southern ores came. Indeed, it is not certain, as yet, what mines of the Marquette iron range, or of the Menominee iron range, are in the rocks of Keewatin age. The writers are satisfied that some of the Marquette mines (particularly the Jackson mine) are in the Keewatin, and that others (particularly the Buffalo, the Queen, and others near them) are in the Taconic (Huronian). They also are inclined to place all the Penokee Gogebic iron range in the Taconic (Huroninn). Indeed, it is quite likely that the larger number of the south-shore mines are in the later formation. This judgment is based on an examination of the field relations of the strata, and was formed some years ago. It is a fact confirm- atory of the correctness of this conclusion, that the average analy- sis of the ores from the south-shore mines indicates a considerable difference from that of the Vermilion ores of Minnesota — that, too, when the possible Keewatin oresof the south-shore mines cannot be separated accurately in the calculation, from those of Taconic age.

This contrast should be further examined, for it has a bearing on theories for the origin of the respective ores. It is probable that no chemist will question the statement that the presence of a larger percentage of lime, manganese, sulphur and water in the Taconic ores is an indication of their greater amenibility, in the process of accumulation, to the ordiuary methods of suba£rial sed- ementary, fragmental deposition, with the possible presence of organic matter. In other words, the chemical characteristics of thn Taconic ores, so far as they can be made to indicate the physi- cal conditions that prevailed at the time of their origination, are in harmony with their stratigraphic features. That is, they require both fragmental deposition, and successive alternations in the strata, from sandstone to shale, from shale to sandstone, and then possibly to limestone — or a mingling of all these principal ingre- dients in the same stratum. This will give the ores certain defi- Lite relations to the enclosing strata, and the mines may havechar-

*On a possible chemical origin of the iron cres of the Keewatin in Minnesota. Amer- ican Geologist. Vol. IV., p. 293.

Iron Ores Of Minnesota. 83

aoteristio hanging and foot walls, such as the Gogebic mines are known to possess.

On the other band the presence of a greater amount of magne- sia in the Keewatin ores indicates a s)mpathetic alliance with the characters of the enclosing green schists. Those schists, as will be farther explained under the head "origin of the Keewatin hematites," are primarily derived from basic volcanic ejecta. They are not the product of ordinary fragments! accumulation under the abrasion and transport of oceanic waters. They were rapidly deposited, so rapidly that they acquired very great thickness. Under such conditions organic matter would be entirely excluded from the gathering sediments. There would be but scant oppor- tunity for the formation of carbonates, for the deposition of lime, for the retention of sulphur in the sedimentary products, or for the slow evaporation that usually marks the gathering of manga- nese. If iron was accumulated then, by any method, it would be expected to partake of the prevailing characters of the enclosing strata. What more natural than that it should show a compara- tively large percentage of magnesia, which is the chief alkaline base of the green schists. The Keewatin iron therefore not only has a chemical alliance with the green schist, but structurally this alliance, through the chemical reactions that took place in the agitated Keewatin ocean, is made still stronger by reason of the co-relations which they manifest, such that only chemical forces could have established. As it is intended here, however, to men- tion simply the distinguishing qualities of the Keewatin hematites, a discussion of these relations is deferred to a later chapter.

Excellence Of The Keewatin Ores.

To conclude this sketch of the quality of the Keewatin ores from Minnesota, attention will be called to the comparative grade of excel- lence which they maintain. This grade is not to be established by selecting individual analyses, nor by the analyses, however numerous of parties who might be supposed to have some interest in their high standing. As has already been stated, the recognized grades of the iron ores of the country are established by repeated assays, beginning with mine owners, then going to the shipping officers, thence to the agents or sellers, then to the purchasers, and lastly the users. Thus all the ores are put to a very thorough test. The average results of these assays, sometimes amounting, during a single season, to several thousand teats, are taken as the grade- standing of the respective ores.

An extensive comparison of the published grades of the princi-

Bulletin No. Vi.

pal ores of iron has demonstrated that THE KEEWATIN OBEs of MINNESOTA, AS PRODUCED FROM THE MINES AT TOWEB AND ELY, ABE POBEB THAN ANY IBON OBES MINED TO ANY EXTENT IN THE WORLD. This statement is based un the analyses published by James M. Swank,* the United States census (10th), William P. BIake,t and by Pickands, Mather & Company, of Cleveland. Those analyses that show the quality of the Lake Superior ores, published by Mr. Swank, are as follows :

The Marquette Range.

AVEBAGE QUALITY OF THE OBE OF THE REPUBLIC MlNE, HAB- quette, Mich. — Shown by fourteen analyses. From A. P. Swine- fords's "Mineral Resources of lake Superior." [After Swank.]

(17.75

,09

Km

toe

88,40

88 Ja

A..

Phosphorus

Sus

L)

Ma aria

"The iron ore of the Champion Mine shows 67 per cent of iroD, 3 per cent of silica, and .03 per cent, of phosphorus. Several an- alyses of West Republic ore that are before us show iron rang- ing from 66.483 to 68.683 per cent., and phosphorus ranging from .039 to .054 per cent. Two analyses of the specular ore of the Lake Supebiob Mine give the following results:" '

Metallic iron , .

Silica

Alumina

Lime

Magnesia

Phosphorus...

Menominee Range.

Vulcan.

Cyclops.

Norway.

Quinnesec.

Iron

6.8b0

A bird's eye view of the production and Characteristics of the Iron ores In the United States, 1885. (In mineral resources of the United States, William*, for 1883-4.) t Report on Iron and steel, Vienna International exhibition, 1873.

Iron Ores Of Minnesota.

The Gogebic Range.

Colby Mine.

Iron and manganese —

Metallic iron

Phosphorus

Silica

Manganese

" Most of the analyses of the iron ores of this district that have been made show metallic iron ranging from 50 to 66 per cent."

Iron Mountain, Missouri.

The following analyses were published by Mr. W. B. Potter, in 1884, in the Journal of the United States Association of Charcoal Iron-workers [after Swank : J

Peroxide of iron. Protoxide of iron

Silica.

Alumina..

lime

Magnesia.

Manganese.

Sulphur ,

Phosphoric acid.

Surface ore.

Bluff ore.

Metallic iron Phosphorus..

2.F00

trace

traoe

" A statement which we have received from the Iron Mountain Company gives the average analysis of a series of samples of No. 1 ore from Iron Mountain as follows :"

Metallic iron.

Silica

Sulphur..

Phosphorus.

65.50T0

Bulletin No. Yi.

Pilot Knob,' Missouri.

Peroxide of iron Protoxide of iron

Bilica

Alumina

Lime

Magnesia

Manganese ,

Sulphur

Phosphoric acid.

Metallic iron, Phosphorus .

none

trace

none

Simmons Mountain, Missouel

Peroxide of iron.

Silicic acid

Alumina

Lime

Mngnesia

Phosphoric acid .

Metallic iron. Phosphorus. .

Cornwall Ore Deposit, Lebanon Co., Pennsyl- Vania.

Results oj' "six samples selected to give a general average of the quality of the ore." — [Swank.]

Nol.

No 2.

No 3.

No 4.

No 5.

No 6.

Magnetic oxide of iron.

trace trace trace

trace

Oxide of copper

trace l.(KX) 0.03J

trace 28.1*0

Oxide of cobalt

Magnesia

trace

Phosphoric acid

Copper Dvrites

Iron pyrites

Water, etc

Metallic iron

Metallic copper

Phosphorus

Sulphur

Iron Ores Of Minnesota.

Salisbury, Connecticut.

Ssqu'oxide of iron

Sesquioxide of manganese

Silica

Sulphur

Phosphoric acid

Lime, magnesia, alumina, water, etc

Metallic iron

Metiillio manganese.

Sulphur

Phosphorus

Davis.

Chat field.

53.0T0

Old Hill.

'The pig iron produced from the Salisbury iron ores is in high

repute for the manufacture of car-wheels and of rolls for rolling mills, but it is also in demand for all purposes requiring great strength and tenacity. More than a century ago there were many forges in this district which produced bar iron of superior quality. The American navy has been supplied with many guns made from Salisbury iron. Only the ore of the Davis mine appears to be adapted to the manufacture of steel." — [Swank.]

Port Henry, New York.

Seven Analy8E8.

Magnetic oxide of iron

Phosphoric acid

Equivalent to —

Metallic iron

Phosphorus

88.772,76.608 81.381 81.559 84. 623 92. 78

1.513 4.227

4.694 3.297

3.495 .71

"The quality of the iron made in this whole region is most excellent, and it enjoys a high reputation for various uses. As a rale the iron ores of this district are not adapted to the manufac- ture of any kind of steel, but some Bessemer pig iron is made in the district, and some mines produce ores the blooms and billets from which have been used in the manufacture of crucible steel."

Bulletin No. Vi.

Prof. W. P. Blake has given four analyses of ore from the "Aren- dal vein," Essex county, N. Y., in the report on the Vienna Inter- national exhibit,* showing a range of metallic iron from 54 to 58 per cent as follows:

Magnetic oxide of iron Oxide of manganese.. .

Alumina

Lime

Magnesia

Sulphur

Phosphoric acid

Silicic acid

Water

Equivalent to. . .

Metallic iroD

Metallic manganese . . .

Phosphorus

Sulphur

trace

trace

Steeling Mines, Okange County, N. T.

Iron

Oxygen

Silica

Sulphur

Phosphorus

Alumina

Lime

Magnesia

Oxide of manganese

Cook mine.

Scott

mine.

none.

none.

Tilly Foster Mine, Putnam County, N. Y.

Magnetic oxide of iron 67 .41

Oxide of manganese 30

Silica 11.75

Alumina. 3. 50

Lune 2.15

Magnesia 13. 24

Sulphur 08

Carbonic acid 2.30

Phosphoric acid 05

Metalliciron 48.82

♦Iron and Steel, p. 287.

Ibon Ores Of Minnesota.

New Jersey Ores.

Magnetic Ores From Sussex County.

M*gnetio oxide of iron. Oxide of manganese. . .

Silica.

A lamina

Lime

Magnesia ,

Sulphur

Carbonic acid. . . Phosphoric acid Graphite.

Metallic iron.

Hill vein.

Furnace v*n.

"A larger general average of New Jersey magnetic ores would show a higher percentage of metallic iron and would be more fav- orable in other proportions for special purposes. For example, the ore of the Richard mine, in Morris county, owned and operated by the Thomas Iron Company, averages 60 per cent, of metallic iron, and contains some phosphorus but no sulphur."

Cranberry Ore, North Carolina.

irr-

Maffnetic oxide of iron , , T T . t - T .

Oxide of manganese

Alumina

Maffnesia

Water

SH ica. nvroxene. etc

fiulnhur

PhosDhorlc acid

trace

Metallic Iron ,.,,,..,,,

"North Carolina has many other deposits of magnetic and hem- atite ores, which have been fitfully worked in a small way for more than a century, but none of these deposits, not even the Cranberry "ore bank," will compare in extent with the immense deposits of lake Superior, the Iron Mountain and Pilot Knob in Missouri, and the Cornwall "ore hills" in Pennsylvania. The coal deposits in North Carolina are as yet practically undeveloped."

ALABAMA, TENNESSEE, KENTUCKY. The following analyses will show the general quality of the southern iron ores. These states do not as yet produce any ap-

Bulletin No. Vi.

preciable quantity of steel. Very small qunntities of ore suitable for the manufacture of Bessemer steel have been discovered.

Alabama Ore.

Oxide of iron

Oxide of manganese

Alumina .'

Lime

Magnesia

Silica

Phosphoric acid —

Magnetite

Red Hematite.

Metallic iron Phosphorus . .

Kentucky Ore.

Peroxide of iron 76.070

Alumina 2.590

Lime 130

Magnesia 281

Silica 8.180

Phosphoric acid 1 .000

Water 12.310

Metallic iron 48.00

Manganese 48

Phosphorus 70

In general the "fossil" ores of the southern states range from 39 to 56 per cent, of metallic iron, and are too high in phosphorus for the manufacture of Bessemer steel.*

TENNESSEE ORE. Mr. P. N. Moore gives the following analysis of Tennessee ores. They were made by Dr. Peter and Mr. Talbutt, from samples col- lected by Mr. Moore. No. 1 is the upper or soft ore from the val- ley near the Virginia road a short distance above Cumberland Gap. No. 2 is the same ore from the ridge below Cumberland Gap. No. 3 is the middle or hard ore from the ridge near the same place as No. 2.f

Iron peroxide

.81*

Alun ina

Lime carbonate."

Magnesia

Sulphuric acid

trace.

Silica and inRoluble silicates

Total

Metallic iron

Phosphorus

Specific gravity

*A. S. McCreath, Trans. Am. Inst. Min. Engineers. Feb. 1887.

♦Geological sur and Cap, Par V

♦Geological survey of Kentucky. Report of the Iron ores of the vicinity of Cumber- "" Vol. IV. Second Series, p. 252.

Iron Ores Of Minnesota.

Great Britain.

The iron ores of Great Britain are found in the Carboniferous limestone, the Goal Measures and in the Lias.* As a class they are very different, geologically and structurally, as well as chemically, from those of Minnesota. They are clay ironstones, and black band ores, with some red hematites. Their percentage of metallic iron ranges from 28 to 66 per cent They have a variety of impur- ities, such that they are generally not suited to the manufacture of Bessemer steel. The most important hematite mines in England are those of Ulverstone in Lancashire, and Whitehaven, in Cum- berland (Bauer man), which occur in very irregular deposits in the Carboniferous limestone. The following analyses of these ores are given by Bauerman (Treatise on the Metallurgy of Iron, 1872, p. 68).

Peroxide of iron

O.lU

Protoxide of manganese

A In to ma... T . . . . ,

Larue

Phosphoric acid

Sulphuric acid.

Bisulphide of iron

0.(6

Insoluble residue

Total

The same authority gives the following analysis of steel-making Bessemer ores employed at Barrow-in-Furness iron works, Lan- cashire. No. 1 is Park ore (best rough), No. 2 is Lindal cote (puddling), No. 3 is Whitrigg's (puddling), and No 4 is from the Mouzell mine (best).

trace

o

Peroxide of iron

Alumina

Protoxide of manganese

Lime

liAfrnefrin

Water.

Phosphoric acid

Sulphuric acid

trace

99..r,0 ! 58.33

Gsroonio acid

1 4.19 j 7.36

1 54.07

!

Silica

Total

Metallic iron

Percy. Memoirs of the Geological Survey of Grout Hritain. The iron ores of Great Britain, Part I.

Bulletin No. Vi.

Scandinavia.

Of all the foreign ores those of Scandinavia approach nearest to the excellence, and the geological age, of the hematites of Min- nesota, and of the Scandinavian ores those from the provinces of Upsala and Kopparberg are the most noted. The following table is made by taking the average of the ten analyses given by Mr. W. P. Blake in his "Report on Iron and Steel, "Vienna exposition, of ores from the parishes of Films, Dannemora, Alunda and Lena, and the same of the first forty-three analyses given from the province of Kopparberg. These analyses were made by Swedish chemists, and give results probably above that which would be got by the regular method of average analysis by iron dealers.

Magnetic oxide of iron. . Protoxide of manganese

Phosphorus

Sulphur

Metallic iron

Average of

10 analyses

from Upsala.

Average of 43 analyses

from Kopparberg.

♦73.23

"The amount of iron in the Swedish ores varies from 30 to 70 per cent. It is, however, usually about 45 or 50 per cent. The 'mine ores' contain usually very little phos- phorus, and among those most free from phosphorus are the ores from Dannemora, in Upsala, with 0.003 per cent of phosphorus, and from Persberg in Wermland with 0.004 to 0.005 per cent, of phosphorus. Usually the amount of phosphorus varies between 0.005 and 0.05 per cent., although there are some with a tenth of one per cent" (Blake).

Spain.

Large quantities of Spanish ore have formerly been introduced in the United States. They are from the left bank of the river Ner- vion, above the town of Bilbao, province of Biscay, associated with rocks of Cretaceous age. They are red and brown hematites, prin- cipally the latter, and have the following chemical qualities, according to Mr, J. Arthur Phillips, f

In making the average the protoxide and the sesquioxide are not reckoned separ- ately, t A treatise on ore deposits, p. 378, 1884.

Iron Ores Of Minnesota,

Ferrio oxide

Alumina

Maoganous oxide

Lime

Maguesia

Silica

Sulphuiio acid

Sulphur

Phosphoric acid . .

Carbonic acid

Combined water . .

Metallic iron

Bed ore .

Red ore.

trace

Brown ore.

.(5

Cuba.

According to Mr. J. P. Kimball (Am. Jour. Sci. Vol. xxviii, Dec. 1884, p. 426) the iron ores of the Juragua hills, province of Santiago, Cuba, have the following chemical character, based on numerous average proximate analyses from commercial samplings: Moisture, 0.24 to 0.81; silica and insoluble, 5. to 10.5; phosphorus, 0.009 to 0.065; sulphur, 0.045 to 0.248; and iron 61. to 68.5.

OTHER COUNTRIES. The principal iron ores of France are of Jurassic age. Those of Belgium are, like those of England, of Carboniferous or Permian age. The German iron ores are Devonian in part and in part Car- boniferous. Some are also Jurassic, and some are associated with masses of greenstone penetrating the Silurian rocks. The Russian magnetites are from porphyry rocks on the east side cf the Ural chain. Other ores are in the Urals, forming lodes and bedded masses in hornblendic rocks and in crystalline schists. In the western Urals are found Carboniferous rocks carrying carbonates and brown hematites. Of these Russian ores none but the eastern magnetites can be supposed to approach the high grade shown by the Minnesota hematites.

The Minnesota Hematites.

Chemical Analyses.

Numerous analyses of the Vermilion ores are published in the thirteenth annual report. Others are given in the fifteenth and sixteenth reports. The following lists have more recently been copied by us from the records of the assay laboratory at Tower.

Bulletin No. Vi.

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Bulletin No. Vi.

'Analyses of samples from the diamond-drill cores and from other

places at Tower.

Date.

April

April

April

May

May

Juue

26,1888. 26, 1888. 23, 1888. 12, 1888. 23, 1888. 11, 1888.

June 11, 1888. . June 11,1888..

June June July July Aug. Sept. Sept.

Sept.

Oct.

Oct.

Oct.

Oct.

Oct.

30,1888. 6. 18h8. 10, 1888. 21, 1888. 12, 1888. lb, 188.

19, 1888. 12, 1*88. 18, 1888. 25,1888. 30, 1888. 30,1888.

Oct. 30,1888.

Dec. Dec. Dec. Dec. Dec. Dec. Dec. Dec. Dec. Dec. Dec. Dec. Dec. Dec. Jan. Jan.

8,1888.

8, 1888.

8,1888.

8,1888.

8,1888.

8, 1888.

8,1888.

8,1888.

8,1888. 15, 1888. 15, 1888. 22. 1888. 23,1888.

5, 1889. 23, 1889.

Jan. 23,1889..

Feb. Feb. Feb. Feb. Feb. Feb. Feb. Feb. Feb. Mar. Mar. Mar.

15, 1889. 15,1889. 15, 1889. 15, 1889. 15,1889. 23, 1H89.. 23,1889..

1,1889..

1,1889..

1,1889..

Mar. 11,1889.. Mar 14,1889.. April 12, 1889.. April 12, 1889.. July 15,1889..

July 15,1880..

July 15,1889.. July 15, 1889..

Metallic Iron.

Phos- phorus.

Silica.

Remarks.

10 in. vein at 10 in. vein at

Drill core from F. hole, 4 ft. vein.

Drill core from F. hole, 38 ft. vein.

Ely mine. No 2 stock pile.

Stone mine. No. 2 stock pile.

Sec. 26. 63-12, from Mr. Bacon.

Drill core sample from 47 ft., 10 in. vein at

E. Tower, 25th ft. Drill core sample from 47 ft.

E. Tower. 46th ft. Drill core sample from 47 ft.

E. Tower, 3d foot. Stuntz mine, west stope. Stuntz mine, east stope. Tower mine, N. of No. 9 pit.

3 cars Breitung No. 16. Red Lake.

4 cars Breitung, No. 14 pocket, lied Lake . Montana, sampled

From a drift at Jasper Peak, sampled by

Capt. Wallace. Montana.

2 cars S Lee pocket. Bess. Red Lake. Montana pit. Bessemer Montana pit, Bess.

Diamond drill core. Hole at S. Lee hill. Diamond drill core. Hole T.,29 ft. vein at

Stone. 10th foot. Diamond drill core. Hole T.,29 ft. vein at

Stone, 19th foot. No. 1 pit; No 1 stockpile. Nos. 3 and 4 pits; No. 1 stockpile. Ely pit; No. 1 stockpile. No. 8 pit; No. 1 stockpile. No. 8 pit; No. 2 stockpile. No. 3 pit; No. 2 stockpile. No 9 pit; No. 1 stockpile. No. 9 pit; No. 2 stockpile. South Lee stockpile. North Lee stockpile. No. 11 pit; stockpile. No lopit; stockpile. No. 6 pit; No. 1 stockpile. No. 17 pit; No. 1 stockpile. No. 19 pit; stockpile. Drill core Z. hole at Stone; 23 ft., 10 in. vein

last 10 feet Drill core, Z. hole at Stone; 23 ft. 10 in. vein

first 8 feet. Drill core, Z hole at No. 3, 3d to 19th foot. Drill core Z. hole at No. 3, 19-24 foot. Drill core Z. hole at No. 3, 3d foot. Drill core Z. hole at No 3, 37th foot. Drill core Z. hole at No. 3,4 ft. 2 in. vein. Drill core Z. hole at No. 3, 24th - 35th foot. Drill core Z. hole at No. 3, 35th foot. No. 5 pit; No. 1 stockpile. No. 5 pit; No 2 stockpile. No. 5 pit; No. 2 stockpile. No. 5 pit; No. 1 stockpile. Drill core from Z. hole at No. 3, 623d ft.

from surface. 39 cars Bess, from No. 3. B.hole at No. 3, 13 ft. vein, 127 ft. from surface. B. hole at Stone. 4th ft 350 ft. from surface. B. hole. 8th ft , 382 ft. deep. HH. hole at Montana, 22 ft., 6 in. vein, 202

ft. from surface. HH. hole at Montana, 8ft., 6 in. vein, 208ft.

from surface. HH.hole at Mon.,3ft.vein.l98ft.from surfaco H H .hole at Mon.,1 f t.vein,255f t.from surface

By reference to plates vn and x the location of some of the

Iron Ore8 Of Minnesota. 97

drill cores, above analyzed, can be seen, and their depth below the surface, together with their relations to the green schist.

Analyses of Keewatin hematite from X. W: Sec. 64, 2-14.

(By Prof. J. A. Dodged

No 1. No. 2.

Silica 21.70 5.26

Lime 0.21 0.15

Phosphorus 0.17 0.18

Magnesia trace trace

Manganese none none

Titanium none none

Sulphur none none

Mag. oxide 77.62 92.76

99.70 9a85

Metallic iron 56.21 67.11

Samples from town 62-15 were analyzed in 1875 by Prof. A. H. Chester, one from sec. 27, giving 6425 per cent metallic iron, one from sec. 28, giving 67.77, and one from sec. 33, giving 65.19. An average is given below of the analyses of all the samples obtained at that time by Prof. Chester.

From T. 62-15, sees. 28, 29 and 30. (Average result.)

(By A. H. Chester.)

Mica 7.57

Alumina 1.89

Phosphorus traoe

Sulphur 0.05

Oxygen with iron 27.11

Metallic iron 63.26

Total 99.88

From Vermilion Lake. (Assorted samples in 1880.) (By A. H. Chester. Clinton, N. Y.>

No. 1. No. 2.

Silica 8.39 8.89

Iron 6693 66.43

Alumina 0.74 0.85

lime 008 traoe

Phosphorus 0.011 0.006

Sulphur 0.01 none

Oxygen 28.695 28.477

99.856 99.653

The average quality of the ores is, however, indicated most reli- ably by the advertised grades And guarantees of disinterested par- tita. Pickands, Mather and Company, Cleveland, O., who have handled the Minnesota ores, as agents for the Minnesota Iron Company, published the following average grades maintained in 1888, and the guarantees for .grades for 1889.

Bulletin No. Vi.

".Minnesota Ore.

" Bessemer hard red specular."

Average of the Analyses for 1888.

Fe 67.93

Si 1.97

P 054

Mn 15

Al,Os 40

MgO 14

OaO 53

HtO 50

Guarantee for 1889.

Fe

P 055

Note. — For the months of April, May and June, 1889, the average of phosphorus in this grade was maintained at .046. No later information was ob- tained.]

"Braddock" Ore.

" Bessemer hard red specular"

Fe

Si

P.

Mn.

Al.O.

MgO CaO HtO

Average of Analyses for

[This grade was not es- tablished until 1889.J

Guarantee for 1889.

Fe..

P 055

[Notb. — For the months of April, May and June, 1889, the average of phosphorus in this grade was maintained at .048, and no later information was ob- tained.]

"NIPIGON" ORE. "Hard Bed Specular.11

Fe 8L. . . .

P

Mn Al.O,

MgO. OaO.. HtO..

Average of an- alyses for 188a

trace

Guarantee for

[Not*—- For April, May and June the aver- age of phospho- rus in this grade was .042

The " Minnesota," " Braddook " and.44 Nipigon" are called Besse- mer ores. The " Vermilion," " Soudan " and "Red Lake " grades are non-Bessemer.

Iron Ore8 Of Minnesota.

"VERMILION" ORE. "Non-Bessemer Hard Red Specular"

Average of an- alyses for 188a

Guarantee for

Pe.

Si

P

Mn.

Al, O.

Ma O

Ca O

H. O.

" SOUDAN " ORE. " Non-Bessemer Hard Red Specular"

Fe Si. P..

Average of an- alyses for 1888.

Guarantee for

" RED LAKE " ORE. Non-Bessemer Hard Red Specular"

Pe

P

Mn... A1.0. MgO.. OaO..

H, a.

Average of an- alyses for 1888.

trace trace

Guarantee for

Bulletin No. Vi.

" CHANDLER " ORE. [From Ely.] "Granulated Specular.9*

Average of an- alyses for 1888.

Guarantee for

Fe

trace

\25

P

Mn

Al, O,

Mff 0

CaO

H8 O

" LONG LAKE " ORE. [From Ely.] " Granulated Specular."

Fe Si

P

Mn A1,08

S

MgO. CaO. H.O

Average of an-

Guarantee for

alyses in 1888.

"COLBY ORE." [From Bessemer, Mich. J " Soft Hematite:*

Fe

Si

P

Mn. ... Al.O,

S

MgO. CaO.. HfO.

Average of an- alyses for 1888.

Guarantee for

Iron Ores Of Minnesota.

MILWAUKEE ORE. [From Wisconsin.] "Soft Hematite."

Average of an- alyses for 188a

Guarantee for

Fe

P

Mh

Al. O,

Mff O

OiO

H, O

NORTH CHAMPION ORE. [Michigan Ore.]

"Soft Hematite."

Average of an- alyses for 1888.

Guarantee for

A

aoo

Si

P

Mh

Al, O.

Ug o

(kO

H.O j

The amount of each grade of ore mined and shipped between December 1, 1888, and August 1, 1889, from the Minnesota mine, at Tower, is as follows. All but 12,797 tons of this was shipped between April 22, 1889, and August 1, 1889.

Vermilion, tons. 69,476

Soudan, tons. 32*372

Red Lake, tons. 36,998

Minnesota,

tons.

141,083

Braddook, tons. 13,459

Nipigon, tons.

Total,

tons.

314,522

Average analyses of shipments by the Minnesota Iron Company, season of 1889. The Minnesota, Braddock and Nipigon grades are regarded by the mine owners as Bessemer ores, in rank according to the order named, and the rest as non-Bessemer.

Bulletin No. Vi.

MINNESOTA GRADE. Total shipment in 1889, 227,492 tons.

Laboratory where the analyses were made.

Minnesota Iron Company.

Two Harbors ,

Illinois Steel Company... .

Carnegie Bros.

Battle & Nye

Cremer

Average.

Number of

tons averaged

by each.

18,000 227,492

40,000 140/ 00

4,000

A verage

percentage

of iron.

Average per- centage of phosphorus.

BBADDOCK GBADE. Total shipment in 1889, 15,647 tons.

Minnesota Iron Company.

Two Harbors

Rattle & Nye

Cremer

Average.

NIPIGON GRADE. Total shipment in 1889, 40,599 tons.

Minnesota Iron Company.

Two Harbors

Illinois Steel Company. .

Rattle A Nye

Cremer

Average.

VERMILION GRADE. Total shipment in 1889, 101,551 tons.

Minnesota Iron Company.

Two Harbors

Carnegie Bros

Rattle & Nye

Average.

SOUDAN GRADE. Total shipment in 1889, 67,545 tons.

Minnesota Iron Company,

Two Harbors.

Illinois Steel Company.. . ,

Rattle&Nye

Cremer

Average.

aooo

8.(00

6,000

Iron Ore? Of Minnesota.

RED LAKE GRADE. Total shipment in 1889, 64,986 tons.

Minnesota Iron Company

Two Harbors ,

Illinois Steel Company

Battle A Nye

Oremer

Average.

5,000

64,985

18,000

4,000

8,000

Percentage Of Each Grade Shipped.

Minnesota 44.25

Brhddook. 2.90

Nipigon 7.59

Vermilion 20.32

Soudan 12.78

RedLake 12.16

From this it appears that considerably more than one-half of the ore mined is low in phosphorus, and that nearly one-half of it contains over 65 per cent of metallic iron and less than six-hun- dredths of one per cent of phosphorus. The rest of the output is but slightly below the Bessemer grade of phosphorus, and its grades (Vermilion, Soudan and Bed Lake), are guaranteed to run respectively not less than 66.66, 65.00 and 62.00 per cent in metal- lic iron. It is probable that individual mines in other countries can be found that would show an equally low percentage of phos- phorus, and others that might run as high in metallic iron. But it is not likely that there is a mining plant in the world that can combine in its year's product, a guaranteed standard of excellence so high in both these respects, and enter into contracts to furnish of such ore 300,000 or 400,000 tons per year. We do not hesitate to claim, therefore, for the Minnesota ores and their annual out- put, in point of quality and quantity, the leadership of the world. The ores of Dannemora, in Sweden, approach nearest this standard. They excel in their low phosphorus, but their product in tons is insignificant in comparison with that of Minnesota.

(5). Origin of the Keewatin Hematites. Our attention was directed to this problem at the outset of this investigation, and it has been continually under consideration. No one who visits the iron mines, be he geologist or chemist, can fail to be impressed with the perplexities that surround this question. The whole en- vironment, physical and chemical, must be satisfied when this question is answered. It will not be sufficient to assume an answer that will be suitable for one part of the phenomena but transgress the other part. When we remember that the physical features of the crystalline rocks, as they are found in the north- west, have not been even yet fully studied, and are far from being understood — not to mention discordance among those who think

104 Bulletin No. Vi.

they do understand them — it becomes apparent that it is not yet time to settle conclusively on any theory for the origin of the hem- atites of the Keewatin.

As we pursued the investigation of this problem we became familiar with the literature of the subject, and this has resulted in the preparation of another chapter in this bulletin on the origin of the ores of iron, in which the various theories which have been proposed for the existence of iron ores of whatever formation are classified, and a bibliography is added which, because it is the result of considerable study of this subject, not only has an indirect bearing on the problem presented to the Minnesota geo- logist, but will also be found serviceable to any student who encounters similar problems in any part of the country. In that chapter all the various theories are presented, and briefly dis- cussed, and some inferences are drawn from the review on the progress and development of theory on the origin of ores from the time of Werner until now.

It is sufficient at this place to say that the writers have earnestly studied the possible applicability of all these theories to the Kee- watin ores. They found but four of them that were within the range of possibility as an explanation of the Keewatin ores, and one of those was set aside as inadequate very soon after they attempted to apply it. We refer to that which considers the hem- atites as eruptive, that which considers them the result of chemi- cal substitution of iron oxide for a carbonate, that which considers them as derived from original deep-sea deposits, and that which considers them a secondary product from the decomposition of basic rocks and the concentration of the iron oxide in drainage basins. These are included in Nos. 2, 8, 17 and 18, as the theories are classified, after Julien, on another page. The eruptive theory, (No. 2), the most prominently presented when we began the work, was duly considered first. The first year's work closed with insuper- able objections heaped up against it, and these have multiplied as the study has progressed. At the same time, on the abandonment of the eruptive hypothesis, that of possible chemical substitution, after the formation of the rocks, of iron oxide for a carbonate, either of lime or of iron (preferably lime) was tentatively held and presented in the fifteenth annual report* (Nos. 8 and 17.) Prof. Irving, who was at that date at work on the same problem, came to the same view, but considered that the original carbonate was that of iron, in the form of siderite.f Further examination in the field

Op, olt. p. 246.

t Am. Jour. Sol. (3) XXXII, 255

Iron Ores Of Minnesota. 106

and further study of the facts before ascertained, indicated that there could not have been such a substitution of iron oxide for lime, or iron carbonate, since the formation of the ore; but that the ore and the country rock were indissolubly allied in manner and time of origin, and that the ocean's waters which accumulated one must have ootemporaneously deposited the other. By this time also the distinctness of the Keewatin formation from the Taconic (Huronian) had become established, and this allowed the consider- ation of the physical and mineralogical characters that distin- guished the Keewatin rocks and ores to be dissociated from those of the later formation. The problem was reduced to finding a plausible explanation of the existence of iron, in any condition, in the waters of the Keewatin ocean. Considering the necessary character of the Keewatm waters, as indicated by the predominat- ing character of the Keewatin sediments, it was plain that chemical causes would be the most potent to produce the ores of the Keewatin, and we had recourse at once to chemical reac- tions similar to those explained in a part of theory No. 18, which refers the iron to the decay of basic rocks. Still we had to con- struct a new theory, in part. We employed a portion of No. which requires the ores to be formed as a deep-sea deposit, but we eschewed the agency of organic matter in the production of that deposit. This, not because of the probable non-existence of decay- ing organic matter at that time, nor because that agency would have caused the deposition in the bottom of the sea of a carbonate of iron instead of an oxide, but because we had presented forcibly before our minds a powerful chemical force existent in the heated and agitated Keewatin ocean itself. We had a continual volcanic supply of basic rocks coming continually in contact with the heated alkaline waters. The chemical reactions that must have ensued, we inferred, were the key to the problem of the origination of the iron in the ocean's waters and for its precipitation at the bottom of the sea among the accumulating sediments. The conclusion we arrived at was announced in a joint paper read before the Ameri- can Association for the Advancement of Science, at the Toronto meeting,* 1890. It is believed to be the only theory that does not contravene any of the established principles of geological and chemical science, and at the same time accords to the physical structure of the rocks and ores and the conditions of Keewatin time their full force and significance. Sufficient has been said concerning the origin and structure

ft possible chemical origin of the Iron ores of the Keewatin in northeastern Published in November, 1889. in the American Geologist.

106 Bulletin No. Vi.

of the Keewatin rocks that enclose the ore bodies. Upon their nature is postulated the chemical environment which is sup- posed to have originated the Keewatin ores. The ocean was agitated by constant outbreaks of internal forces, which were accompanied by the basic ejections which the interior of the earth alone affords. The decomposition of the basic minerals was a rapid and continual process. The solutions went into the ocean's waters. The insoluble parts were distributed by its currents. Those also that were not wholly decomposed were laid down with the insoluble parts of the decomposed minerals. This was, neces- sarily, an "azoic" age, wherever this violent agitation and rapid transportation were in progress. Decomposing organic matter can be supposed to have played no part in the chemical reactions that may have precipitated the iron in the bottom of the ocean. There are reasons for believing that this oceanic condition was world-wide in Keewatin time, but they cannot be entered upon here. It is only necessary to inquire how such products as chalcedonic silica and hematite could have been formed in a sea that at times was seething and steaming with volcanic craters and earth-fissures from which escaped molten rock from below the crust. The descriptions that have been given of the ore and of its intimate relations with the silica bands of the jaspilyte are ample to show that the method of accumulation of one was necessarily that of the other. While they are arranged by sedimentation, it could not have been the result of ordinary erosion and sedimentary transpor- tation that gave these substances their origin. Ordinary sedimen- tation could not select from the products of erosion simply two substances and deposit them in regular lamination, in chemically pure condition. Some selective and ever- active force was at work which was able to extract these only from the over-charged Kee- watin waters and reject all the rest. The product is almost chemi- cally pure, for the variations in the jaspilyte, whether in color or in composition, are due solely to variations in the relative propor- tions of silica and hematite. The exceptions to this fact are so rare that they may not be considered in stating the general principle, though they serve, like all exceptions and variations from general principles, as finger-boards that point the investigator to antecedent as well as subsidiary principles.

When the equilibrium of the surcharged waters was distributed by evaporation or by sudden cooling, such as would ensue when the currents carrying the solutions passed into hotter or into deeper portions of the area considered, a chemical precipitation would follow. This has been stated in the following words by De

Iron Ores Of Minnesota. 107

la Beche*. "Surrounded by seas of inferior temperature, closing in upon the volcanic vents as the heated waters rose upwards, there would be a tendency to have certain substances, only soluble at a high temperature, thrown down, wherever the cooling influences could be felt; as also, when these substances may be borne upwards by the heated waters, to have them distributed by any oceanic cur- rents acting over the locality, supposing that the heated waters either rose to or were produced at distances beneath the surface of the sea where these currents could be felt." This result would so obviously ensue that it is not necessary to quote any other author- ities.

It remains to enquire whether the chemical precipitates that would thus be formed would be silica and iron oxide. Laboratory experiments might be made to demonstrate this. In the absence of such tests we shall quote the views of some chemical and phys- ical geologists whose opinions will be more authoritative than our own.

On this point Hunt says:f The atmosphere, charged with acid gases which surrounded this primitive rock, must have been of immense density. Under the pressure of such a high barometric column condensation would take place at a temperature much above the present boiling point of water; and the depressed por- tions of the half -cooled crust would be flooded with a highly heated solution of hydrochloric and sulphuric acids whose action in de- composing the silicates is easily intelligible to the chemist The formation of sulphides and sulphates of the various bases and the separation of silica would go on until the affinities of the acids were satisfied, and there would be a.separation of silica taking the form of quartz, and the production of a sea water holding in solu- tion, besides the chlorides and sulphates of sodium, calcium and magnesium, salts of aluminum and other metallic bases. Quartz has not only never been met with as a result of igneous fus- ion, but it is clearly shown, by the experiments of Rose, that a heat even much less than that required by the fusion of quartz destroys it, changing it into a new substance which differs both in chemical and physical properties from a quartz. The first precip- itates from the waters of the primeval sea must have contained ox-

*Oeologlcal Observer, 1851, p. 131 In this volume Dc la Beche presents and discusses many of the volcanic conditions and effects which the writers believe were character- istic of Keewatin time, and are exemplified by the Keewatln rocks more perfectly than by any others. Compare pp. 526-536.

tT. Sterry Hunt, The chemistry of the primeval earth, Am. Jour. Sci., Jan. 1858. Smith- sonian Report* 1860, p. 180. Chemical and jreolojrirul essays, 1878. p. 40.

108 Bulletin No. Vi.

idized compounds of most of the heavy metals. The large amounts of silica contained in solution in the waters of some thermal springs and of many rivers, are separated when these waters are exposed to spontaneous evaporation, partly as silicates of lime and magnesia and partly in the form of crystallized quartz, hornstone and opal. In many different formations beds are met with com- posed entirely of crystallized grains of quartz which have appar- ently been deposited from solution. In other sediments this ele- ment abounds in the form of grains of chalcedony, or as amorph- ous, soluble silica. . The beds and masses of schist, flint, hornstone, buhr-stone and many jaspers have all apparently been deposited from aqueous solutions.*

Prof. A. Winchell thus refers to this primeval ocean and the precipitation of silica, t "The liberated silica would separate, and would be chemically precipitated during the subsequent cooling of the waters, and would thus give rise to the enormous beds of quartz which we actually find among the very oldest strata."

Concerning the precipitation of ferric oxide Yon Cotta says : "There can be no doubt that all true ore-beds were originally formed by mechanical or chemical precipitation from water. Their condition may have been much changed afterwards ; thus under certain conditions hematite may have been formed from limonite."t T. Sterry Hunt says :§ " Those chemical com- pounds which were most stable at the elevated temperature then prevailing would be first formed. Thus, for example, while com- pounds of oxygen with mercury or even with hydrogen, could not exist, oxides of silicon, aluminum, calcium, magnesium and iron might be formed. All the elements, with the excep- tion of the noble metals, nitrogen, chlorine, the related haloids, and the hydrogen combined with these, would be united with oxygen. The volatility of gold, silver and platinum would keep them still in a gaseous condition at temperatures when silicon, and with it the baser metals, were precipitated in the form of oxides." These quotations might be multiplied. The formation of siliceous and irony deposits from oceanic waters is referred to by Gustav Bi- 8chof,|| J. W. Dawson, and nearly all geologists who have written of the chemical reactions of the primeval ocean.

Some general reflections on the chemical reactions that neces-

♦Hunt, Geology of Canada, 1863, p. 574.

+A. Winchell, Sketches of Creation, 1870, p, 69.

*A. treatise on ore-deposits. Translated by Frederick Prime, Jr., 1809, p. 22.

{(Smithsonian report, pp. 186. 189.

I Chemical and physical geology (Cavendish Society), vol. i, pp. 143, 146.

/

Iron Ores Of Minnesota 109

sarily would follow from the conditions that are assumed for the Eeewatdn ocean may not be out of place.

If we consider the character of the rocks that constitute the crust of the earth, we shall find that silica and ferric oxide are omnipresent Silica constitutes forty-five per cent of all the rocks of the earth's crust,* including limestones ; and also nearly one- half of a normal basic tachylyte such as may be supposed to have cooled to form the earliest solid film that encased the earth. Its relative amount, in respect to the other elements of the earth's crust, has neither increased or diminished. It has undergone transformation, and it appears locally abundant or scant, but it is not destroyed nor lost. Whenever it appears as quartz it furnishes the most refractory element of the rocks. It is as quartz that it shows its dominance over all the other rock-minerals. It gives to the rocks structure, firmness, color, durability, and relative insolubility. There is no other element that is so quick and able to assert its dis- tinguishing traits, and to stand independently among the influ- ences and vicissitudes of chemical or mechanical change. Among the rock- making minerals it is the last to disappear in solution, and the first to present itself on re-crystallization. Its relative abundance, compared with the other acids, is so great that when- ever the chemical bases are taken possession of by carbonic acid, which is primarily an element of the atmosphere, it is compelled to take up with any isolated and partnerless domicile that it can find in the clefts of the rocks.

Next to quartz iron appears as regent over the aspects of the mineral kingdom. Its advent in the earliest basic doleritic film, giving it the somber hue that denotes still the "greenstones," was the herald of the place it should hold throughout geological history. Notwithstanding the thaumaturgic feats by which chemical change has transformed the face of na- ture a thousand times, the presence and influence of iron are every- where manifest Whole formations are reddened by ferric oxide. f Were it not for iron every stone would be nearly white. The soils and subsoils would glisten with a painful whiteness. If all the known manganese in the world were confined in the surface soils, and to this were added all the copper and lead, all the silver, all the nickel and all ttaothei coloring metals, the soils in the absence of iron would still oe painfully and monotonously white, except where they might be covered, or colored, by decaying organic matter. As fer- ine la Beche, Geological Observer, p. 627. It la estimated at fifty per cent by Dana, Manual of Geology, p. 40.

tlarael Cook Russell, 8ubacHal decay of wfa. and origin of certain formations. U. S. GeoL Surrey, Bulletin No. 52, 1880.

110 Bulletin No. Vi.

ric oxide and hydrate iron has its stable conditions. These are the most frequent products of the chemical manipulations of the laboratory, and the most common results of the chemical changes of nature.

Therefore, in the problem of the origin of the hematite ores of the Keewatin, since they are intimately associated with the chalce- dooic silica of the jaspilyte masses, we have to do with two of the most abundant, as well as the most self-asserting of the rock- form- ing minerals — quartz and ferric oxide. It is evident, therefore, that if the volcanic conditions were such as we have supposed in Keewatin time, and the Keewatin ocean, in whole or in part, became charged with solutions of the minerals with which its heated waters came in contact, including silica and iron, in what- ever chemical combination, and if then the change of cooling or of evaporation supervened so as to break up the equilibrium of perfect saturation, these two minerals would have been the first to free themselves from solution and to appear as precipitates on the bottom of the sea. They would have been not only the first but they would also have been the most abundant of the chemical precipitates. They would also have continued to accrete as chem- ical precipitates as loog as the Keewatin conditions continued, and if thesame conditions recurred in any later geological age the same chemical precipitates would have been the result*

It is not necessary here to go fully into the subject of the chem- istry of the primeval submarine volcanoes. De la Beche has pre- sented! many of the conditions and considerations on which we have to rely to find the origin of the Keewatin ores. The classic work of Mr. Judd on volcanoes J may be examined by any one who desires to learn some of the more modern aspects and theories of vulcanology, and especially as to the physical laws and dynamic changes that, as geological agents, volcanoes illustrate. It is ad- mitted en all hands that they are the seats of the most violent

We have road with much Interest the Ingenious discussion of Mr. 1. 0. Russell, In Bulletin No. 52, of the U. S. Geol. Survey. He reaches the conclusion that the red color of certain formations is duo to an Incrustation of the sands during the subaerlal decay of the rock from which they were derived. We think this explanation is inade- quate. Not to mention the very problematic existence of lands sufficiently wide to furnish the ten or twelve thousand feet of strata that make up the Cupriferous strata in the state of Minnesota, and which extend from one side of the continent to the other, it is sufficient to call attention to the probable chemical precipitation of forric oxide from the ocean in the same manner as above described fo#the Keewatin. The Cupriferous was a period of great volcanic activity. The same is true of the New- ark . The strata of both are intersheeted as well as cut by basic rook which must have had its effect on the chemical status of the oceanic waters. The sediments of both are prevailingly red, and in the Newark, In Pennsylvania and Virginia, are consider- able beds of iron ore. Compare also J. W. Judd, Volcanoes, p. 74.

tGeological Observer, 1851, pp. 596-534.

Volcanoes; what they are and what they teach. New York, 1881.

IBON OBES OF MINNESOTA. Ill

chemical reactions, as they are also of the most stupendous of phy- sical forces. The various acid gases that are emitted operate to convert iron, lime, and the alkaline* materials in the rocks with which they come in contact into soluble compounds known as sul- phates, chlorides, carbonates and borates. Such waters, especially if heated, are then capable of dissolving silica. They thus become the bearers of all the solid constituents of the rocks. They de- stroy the rocks already formed and then distribute their elements in new places, and in new forms and combinations. In Keewatin time these forces, conditions and changes must have been in a state of constant and intense activity.

(d) Distribution of the Keewatin and the Keewatin hematites.

The rooks of the Keewatin, in the form of sericitic schists, graywackes, argillytes, agglomerates and chloritic schists, are widely distributed in Minnesota and Manitoba. The occurrence of iron ore is but one of their phenomena. Silica in the form of chalcedony is much more widely disseminated through them than iron ore. The geological map that accompanies this bulletin shows the area of the Keewatin in Minnesota. It is not yet possi- ble to give any data for prejudging as to the possible existence of the ore lodes in this or that part of the stratification. It is not yet certain whether, at Tower and Ely, the chronological suc- cession of the strata is from the south to the north or from the north to the south, although some internal evidence has been given under the head of "structure and character of the hematites of the Keewatin" that tends to indicate that at Tower the stratification ascends in the scale from south to north. The most that can be said concerning the distribution of the ore lodes in the Keewatin is summed up in the statement that the ore uniformly accompa- nies the green chloritic schists, or the massive diabasic schists, whether these be agglomeritic or not.

Outside of Minnesota the belt of chloritic schist which carries ore passes into Canadian territory by entering Hunter's island. There is great probability of the existence of valuable deposits of iron ore on Hunter's island, and also further northeast in the direction of their strike. In respect to other parts of the country we cannot speak with any positiveness. We do not know of the Keewatin schists anywhere else excepting northern Michigan, where the same lithology and the same geological relations are manifested about Marquette, and thence to Ishpeming and west- ward as far at least as the gold mines. Some of the Michigan mines, for example the Jackson mine* at Negaunee, are un-

Hfaater and Whitney's report on lake Superior. Part II. p. M.

112 Bulletin No. Vi.

doubtedly in the Keewatin. Others, as the Buffalo, the Queen, the Sam Mitchell, near Negaunee, and others in that neighborhood, are with almost equal certainty in the Taconic (Huronian), which unconformably overlies the Keewatin.* That the Keewatin formation extends into Wisconsin there is great probability, bat we are not sufficiently familiar with the iron regions of that state to speak with certainty. The mines of the Penokee- Gogebic range in the northern part of the state we do not admit within the Keewatin. See plate xv.

Further east there are no positive data for extending the Kee- watin, although it seems to occur in western New England. It is possible that the dynamic change which is discussed in another part of this bulletin, whereby the Keewatin sediments and Keewatin ores were converted to Vermilion mica schists and magnetic ores, prevailed more extensively. The non-titanic magnetic ores of New York, New Jersey, Pennsylvania, Virginia and North Caro- lina, described as interbedded in gneiss and in mica schist, may be the cotemporary analogues of the Keewatin ores of Minnesota, though they are the lithological analogues of the Vermilion, as al- ready described.

(3.) THE ORES OF THE TACONIC. (Huronian. The

Mesabi range. )

Although there is at present no mining in these ores in Minne - sota, they are well known at numerous places. They were indeed the first to attract attention, and were carefully surveyed and ana- lyzed by Prof. A. H. Chester in 1875. They are destined to play a very important part in the future development of the iron in- dustry of the state. They occupy fourfold the area that is occu- pied by the Keewatin ores, and they are nearer the ore-shipping points as well as the iron-using markets. It is on account of this high promise of future productiveness that they are fully described in this bulletin.

♦Compare the seventeenth annual report, pp. 42-45.

Iron Ores Of Minnesota. 113

(a.) Reasons for substituting this name for Animike. In the Minnesota reports the Animike formation has been described in several places, f The taxonomic relations it bears to other forma- tions have been fully presented and need not be dwelt on here. Neither is it necessary to repeat the evidence that exists of its be- ing on the same horizon as the Taconic. One of the most recent discoveries was that made by Mr. E. D. Ingall of the Canadian survey, announced by Mr. Selwyn.J This consists of fossils of Taconic types, whioh Mr. G. F. Matthew refers to radiate animals, or rather to their tracks, and names Taonichnites, also others that he regards tracks of a kind of squid or calamary and names Ctenich- nites. These were found in the Animike rocks of Canada, north of lake Superior, and sufficiently establish the Taconic (Lower Cambrian) age of the Animike formation which has rested here- tofore on general lithology and comparative stratigraphy. The proper name to apply to such a great rock-formation is determined by the law of scientific nomenclature by which that name which was first announced, with adequate description, is always required to be adopted. The term Taconic therefore may properly be sub- stituted for Animike when the formation is referred to in any of its broader features or in comparing it with rocks of the rest of the world. As a local designation Animike will still be useful.

(b.) Nature of the enclosing rocks. (1.) Macroscopic. In northeastern Minnesota the rocks of the Taconic consist chiefly of carbonaceous and argillaceous, but often very siliceous slates and fine-grained quartzytes and gray limestones. Sometimes the quartzytes are coarse, and even become pebbly. Near the bottom of the series is a fragmental quartz-sandstone,§ which, having sometimes an apparent thickness of 300 feet, has been specially named Pewabic quartzyte. What relation this quartzyte bears to that portion of the slaty Animike which becomes conglomeritic, as on the northeastern shores of Gobbemichigama lake, it is impos- sible at present to state, but it is probable that the quartzyte will be found to be nearly on the same horizon, or to be one of the

tgeventh annual report, pp. 9-25, for 1878. Ninth annual report, pp. 61-83; 107-100. Tenth annual report, pp. 86-88; 04-06. Eleventh annual report, pp. 156-160; 16&-170. Thirteenth annual report, pp. 21-24; 134-140. Sixteenth annual report, pp. 65-06; 233-202; 321-323; 352-350. Seventeenth annual report, pp. 46-51; 77-110; 133-135; 186,

tTrmekt of organic origin In the rocks of the Animike group. Am. Jour. Hci.. xxxix (Feb., 1880), p. 145.

ISee the eighteenth annual report. In previous reports the quartzyte wus supposed to lie oner the Animike, and to be the equivalent of the Potsdam quartzyte, but It Is eertalnly older than the most of the Animike strata.

114 Bulletin No. Vi.

fragmental beds of that part of the Animike. When the Taeonic beds are not horizontal, they dip southerly at all angles from three to ten or twenty degrees.

These slates, conglomerates and quartzytes are profoundly af- fected by intermingled eruptive rock material. This eruptive material seems to have been supplied in a manner quite similar to that found so abundant in the Keewatin and which has already been described at length. It is found generally as fragmental, non-porous tuff, interstratified in the formation. There are some beds also that have the appearance of being consolidated beds of basic lava. In general, however, where these basic materials pre- vail there is frequently an insensible graduation from dark trap- looking beds to thin beds of slate. This character has been noted particularly on the shores of Loon lake, south of Gunflint lake. In cases where the Animike becomes more massive and at the same time conglomeritic, as in some parts of the shores of Ogishke Muncie lake, and on the north shores of Gobbemichigama lake, there must have been locally a rapid supply of such basic sedi- ments. It thus makes a " slate conglomerate " similar to that of the Huronian on the north shore of lake Huron, of which probably it is the Minnesota equivalent This should not be confounded with the agglomerates of the Keewatin, suoh as that seen on Stuntz island in Vermilion lake, and at Ely. Generally the Taeonic can be distinguished from the Keewatin by the most evi- dent characters — that of dip being the best guide. The Keewatin is always nearly vertical, and the dip of the Taeonic is often very slight, and rarely exceeds 15 degrees.

The Taeonic, in northeastern Minnesota, therefore, with some periods of quiet, was deposited in the midst of violent volcanio dis- turbance and oceanic transportation. It repeats, or rather con- tinues, but on a much feebler scale, the physical characteristics of the Keewatin, but shows an increased amount of ordinary frag, mental rocks. This similarity is not confined to the presence of basic sedimentary rocks, and their grading by insensible transi- tions to siliceous strata of very different aspect, but the same chem- ical precipitations which took place under such conditions in Keewatin time, also took place in Taeonic time. In the Taeonic (Animike) are frequent beds of flint, some of them being several feet in thickness, (Bock sample 1277), and this flinty texture, derived from the intimate mingling of chemically precipitated silica among the clayey sediments, pervades sometimes several hundred feet of the Animike strata. Besides flint, the Animike holds small quantities of jaspilyte, banded and twisted, with thin

Ibon Ores Of Minnesota. 115

sheets of hematite, in a manner similar to that seen in the Keewa- tin. This has been noted at several places about Gonflint and North lakes, and also at the lower falls of Prairie river, near the town of Grand Rapids, on the east bank of the Mississippi (see rock samples No. 1295, 1310, 1315, 1529 and 1530). There is not however, so far as known, any workable deposit of iron ore of this character in the Taconic that can be compared to those iron lodes that exist in the Keewatin. There are thin and irregular deposits of jaspilyte, styled in the 9th and 10th reports " Gunflint beds," some of them containing considerable quantities of hematite, as at the rapids of Prairie river, and much flint in regular layers, but in general the iron ore that exists in the Taconic in Minnesota is found in other associations, as will be shown later.

In respect to the carbonates, which exist in the vicinity of Gunflint lake, near the bottom of the Taconic, they seem not to be developed on so large a scale as they are in northern Wisconsin. About twenty feet of such cherty carbonate can be stated to occur, at the utmost, and even then it is quite impure with angular frag- ments of chert and flint. It is easily distinguished from all the other strata by the prevalent rusty coating which it carries. We cannot make out, from all the observations that have been made on the Taconic in Minnesota, anything more than a general de- scription of the prevailing rock-strata, and some idea of their suc- cession in the lower part. We have but little idea of the thick- ness of the lower parts, but feel certain that the whole series ex- ceeds one thousand feet in thickness.

1. Basaltic trap and trap-like rock, at various levels, perhaps 200 feet

2. Thin, carbonaceous black slates, perhaps 200 feet.

3. Gray, "feldepathio" quartzytee, sometimes alternating with black slates, perhaps 200 feet

4. Gray, impure quartzytee, varying to black and green, alternating with and changing to massive trap-like beds, or variously blotched by green chloritio or hornblendio ingredients and with magnetite, perhaps 100 feet.

6. Black slates and flint, or chert, banded coincident with the stratifica- tion, perhaps 80 feet.

& Beds of gabbro and titanic iron, perhaps 200 feet.

7. Beds of vitreous quartzyte [The Pewabio quartzyte] interbedded with gabbro and sheets of hornblendic or olivinitic magnetite, perhaps 100 feet.

8. Beds of dark massive conglomerate and breccia, "slate conglomerate," perhaps 200 feet.

9. Bads of carbonate of lime and iron, cementing a breccia of flint and jasper, perhaps 25 feet

10. Beds of jaspilyte, contorted as in the Keewatin, with specular iron intercalated, perhaps 2 feet.*

Prof. B. D. Irving stated (Am. Jour. Hcl. (3), xxxil, that on the norl herrTslde of North lake beds ofjaaper reach an immense development, forming bold cliffs facing d. And farther northeast t he bottom of the Taconic Is characterized by beds of flint.

116 Bulletin No. Vi.

The above may be taken as a rough approximation to the thick- ness and order of the strata of the Taeonic. These parts are not all continuous but give place to some of the others. For instance, Nos. 6, 7, 9 and 10 have each been seen lying unconformably on the Keewatin, or on the Laurentian, and No. 8 is so placed and enlarged sometimes, that it seems to monopolize the base of the formation and to absorb or at least obliterate the characters of the others that are frequently found near the same horizon. It is not certain indeed that it is not a part of the Keewatin.

Following is Prof. C. R. Van Else's description of the parts of of the same formation as it occurs in northern Wisconsin and Michigan.111

The Taeonic in the Penokee-Gogebic region.

"At the base of the series is a cherty limestone member which, in one place, is as much as 300 feet thick, and whioh varies from this to disappearance. The second member is a feldspathic quartz slate. On the average it is from 300 to 400 feet thick, and is composed of green, red and brown fragmental slates which con- tain a good deal of clayey matter. The upper part of this frag- mental member is a pure vitreous quartzyte, the induration of which has been due to the enlargement of the quartz grains ori- ginally deposited as a sandstone. The third member of the series is a belt of non-f ragmental sediments about 800 feet thick, which is known as the iron-bearing member from the fact that all the known ore-bodies and heavily ferruginous rocks occur within it The uppermost member of the series is a thick layer of gray- wackes, gr ay wacke- slates, and mica-schists and slates. This mem- ber is several times as thick as the three lower combined, but in its essential fragmental character it is to be considered as a unit in the series." ,

With the exception of the uppermost member mentioned by Prof. Van Hise these parts have their equivalents in northeastern Minnesota, and even that may be represented in some mica-schists that have been described in the vicinity of Snowbank lake. The graywackes and mica- schists, however, that we have seen in Minnesota have been found to belong, with the possible exception just mentioned, to the underlying Keewatin and Vermilion series.

After this general survey of the rocks of the Taeonic (Animike), it will be necessary to consider particularly the rocks that immedi- ately embrace the ores of this formation. There are four methods

Am. Jour. Scl. (3), xxxvii, 33.

Iron Ores Of Minnesota. 11/

of occurrence of the Taconic ores, as there are four distinct kinds of ore, viz:

1. The quartzose- horn blende (or olivine) magnetite group.

2. The impure jaspilitic-hematite and limonite group.

3. The carbonated iron group.

4 The gabbro-titanic-iron group.

These will be described separately. The first is the most im- portant as a probable source of large quantities of merchantable ore in the near future. The second is interesting because of its genetic resemblance to the jaspilitic ores of the Keewatin. The fourth exemplifies the manner of occurrence of a large body of ores, the value of which/in Minnesota, would be enormous if there could be discovered some metallurgical process for their economic reduction, and the third represents in Minnesota what appears to be an important source of ore in the Penokee-Gogebic range. These occur distinctly and separately, in some places, and when fully characterized manifest features that do not occur in any two interchangeably. So far as these are iron-producing, in Minne- sota, the ore is plainly indigenous and coeval with the formation of the containing rock, although there seems to have been a concentra- tion of theory and a coarser crystallization of the original rock-min- erals in the case of No. 1, in some places, brought about by the heat of the great gabbro outflow, which is frequently in immediate proximity and, in the eastern part of the Mesabi range, maybe con- eidered to have extended over the whole.

1. The quarizose-hornblendic (or olivinUic) magnetite group. The non-titanic magnetic ores of the Taconic are principally found in the coarser parts of the Pewabic quartzyte (1308-9) or intimately associated with it They are typically developed on the north shore of Chub ( Akeley) lake. They are also associated with the occasional jaspilyte masses occurring at about the same horizon in the formation. The jaspilyte found on the north shore of Gunflint lake (1315) is thinly interleaved with magnetite instead of hematite. Considerable deposits of this ore, associated with an olivinitio quartzyte, extend all along the northern limit of the strike of the Pewabic quartzyte southwestward from Gunflint lake, as at Chub {Akeley) lake, Flying Cloud lake,*Gobbemichigama lake (south shore), Frazer lake, Thomas lake, Birch lake, Iron lake, and thenoe westward to Pokegama falls on the Mississippi river. This is in general also the line of strike of the Taconic on its northern limit The rook that immediately encloses this ore is primarily a frag- ments!, rather coarse quartzyte (1322) whose distinct rounded grains are evident to the unaided eye. It is by degrees modified

118 Bulletin No. Vi.

by the mingling of olivine or green hornblende or both, the lat- ter appearing sometimes in nearly continuous layers or sheets co- incident with the stratification, and affording coarse crystallizations (1339). These sheets are apt to be interrupted and to swell out suddenly. They are sometimes partly made up of vitreous quartz and the grains of the quartzy te itself are coarse,glas8y and apparently consolidated by deposition of secondary quartz (1338). The mag- netite appears at first as isolated granules, sometimes showing its octahedral angles (but generally rounded) disseminated through the quartzyte. It prevails over the quarizyte more and more and becomes so abundant that the rock changes to iron ore. At the same time as the magnetite increases, the greenish* mineral which is presumed to be olivine, as well as the fibrous hornblendic min- eral, both' appear. The rock then is heavy and dark-colored. The glistening crystalline cleavages of the hornblendic patches, and the separation of the now coarser crystalline grains of the magnet- ite, leaving their subangular basin-like depressions, affording the principal macroscopic characters. In other parts of the rock there is a scarcity of quartz, and the isolated magnetite grains are scat- tered through the hornblendic mineral. Here also they increase in frequency and break up the continuity of the hornblendic crys- tals, producing, when the rock is broken in certain directions, the granular aspect of a fragmental rock, and so becoming a granular iron ore.

These coarsely hornblendic and olivinitic characters occur in the easterly extension of the Pewabic quartzyte, the former being characteristically developed in the region just west of Gunflint lake, and the latter in the region about Birch lake. Not enough study has been put yet upon the geographic distribution and the genetic and stratigraphic relations of these two irony and magnes- ian minerals in the Mesabi range ores to establish any principle touching their individual genesis or their correlation with the gabbro or with the magnetite, but there is evidently a reduction in the amount of these minerals at the horizon of the Pewabic quartzyte toward the west, and on the Mississippi river they do not occur at all. It is noticeable that this diminution appears to be coincident with the greater divergence of the strike of the Pewabic quartzyte from that of the gabbro sheet, the former going to Pokegama falls, and the latter to Duluth.

The Pewabio quartzyte varies from a coarsely granular rock to a minutely fine one. In its finely granular condition it is as com- pact as chalcedonic silica, and cannot be distinguished readily from it in any way except that it is never white but varies to gray

Iron Ores Of Minnesota. 119

and grayish-green and to darker colors. In this condition it is finely interlaminated, when ore-bearing, either with black mag- netite and some greener sheets that may be parallelized genetic- ally with the green schists of the jaspilyte lodes of the Keewatin, or with impure semi-hydrated limonite. In the latter case the ore is hematite-like and siliceous. It is as hard as a common knife blade, and it is with difficulty that a common knife blade can be made to scratch it enough to show the characteristic color of the ore (366 H). This condition of the quartzyte is sometimes varied still further, by the conversion of the accompanying green element into actinolite (437). This seems to have taken place where the gabbro sheet has sufficiently affected it, or where some metamor- phic agency has operated on the formation. It is a common feature on the Mesabi range in towns 59-14 and 60-13, and is frequent at Black River Falls, Wisconsin. The coarse and evi- dently fragmental phase of the Pewabic quartz jte continues from Ounflint lake to Pokegama falls, and it is also interbedded with gabbro at Duluth, as revealed by the deep well at Short Line park,4 whereas the fine-grained phase is known, so far as it is ferriferous, at points intermediate, and particularly in the country southwest from Gunfiint lake and west of Birch lake. What may be the stratigraphio relations of these phases of this quartzyte it is not possible to state. One may generally, or entirely, succeed the other, or they may have been produced locally and simultane- ously, and hence at the same stratigraphic level — the coarse- grained phase being due to strong sedimentary and transporting agents, with weak precipitating reactions, and the fine-grained phase prevailing where chemical precipitation alone, or nearly alone, caused the siliceous accumulations. Both phases have beeft seen in immediate superposed contact on the older formations, and in some instances they are separated from the granite by a thin stratum of reddish and contorted jaspilyte. [Since the foregoing was written an important discovery of magnetic ore has been made by the Stone Iron company, in the Taconic on Sec. 18, 59—14. We have not been able to see it, but from samples sent, and from verbal descriptions we learn that the ore "appears to stand vertical" and the outcrop can be traced for nearly a mile east and west, "granite" lying both to the north and south. It runs across the S. E. j of Sec. 13, 69—16, and on to the S. W. ± of Sec. 18, 59—14, passing northeastwardly into N. W. Sec. 18 not far from the center of the section. Samples received from Capt W. Bice, who has charge of its development, show that the ore is probably in the

bulletin No. 6. p. 34. Natural Otis In Minnesota.

120 Bulletin No. Vi.

Taoonic rooks, at least is in the quartzyte known in this report as Pewabic quartzyte. The "slate" which is from the north side of the ore is harsh and siliceous, like that seen in the bottom portions of the Animike about Gunflint lake, gray in color and slaty in the direction of the bedding, being actually a thin-bedded feldspathic gray quartzyte of moderately line grain, evidently of f ragmental ac- cumulation, with mica scales characterizing some of the bedding planes. The "slate" that comes from the southerly side of the ore is a dense, impure, dark, chalcedonic jaspilyte, embracing con- siderable magnetite, in finely disseminated crystalline grains, also some pyrite, which, in some cases, is converted to limonite.

A magnetic belt has also been discovered running along north of

the hematite belt in Sec. 3, 58 — 18.]

2. The impure jaspilitic-hematite-and-Umonite group.. As an iron ore producer this group is not yet known to be important. The hematite-jaspilyte beds that outcrop at the rapids of Prairie river, near the Mississippi river, are the most important that are known. This group repeats in the Mesabi range the same litholo- gic peculiarities that have been described for the jaspilyte beds of the Vermilion range, but they are displayed on a small scale. The contorted outlines of the ribboned jasper are equally evident, but the ribbons are not so wide, nor so long. The colors are as bril- liant, but they shade more quickly into each other. The red jas- per is also occasionally blotched or peppered with varying propor- tions of hematite. Sometimes there is a homogeneous mixture, in form of round small grains of red hematite, disseminated through a stratum or a lenticular mass of blood-red jasper. The reverse is seen also, and the red jasper is scattered through a mass of red hematite: Even the best iron ore, (hematite) so far as seen at Prairie river falls, is flecked with siliceous red specks and veins, (compare 1527 and 1530). At the other end of the Mesabi range an outcrop of this parti-colored jaspilyte was seen on the north side of Gunflint lake,* and it there lies immediately on the syenite of the Giant's range. By a slight extension of the significance of the term jaspilyte it may be made to cover a large amount of the flint, oolitic jasper or bloodstone chert and gray quartz and quartzyte with which the lowest part of the Animike is marked, in all the region of Gunflint lake. Generically and genetically these are the same. The difference of color is due to varying amounts of color- ing material, (the chief being iron) and to difference of chemical combination. Indeed, if the chalcedonic condition of the silica which in many places characterizes the iron-bearing portion of the

♦Sixteenth report, p. 73 and p. 342.

Iron Ores Of Minne80Ta. 121

Animike, be allowed its full significance and the term jaspilyte be extended co-ordinately, we shall find the typical ribboned jaspilyte which gave origin to the term, undergoing a wonderful enlarge- ment and metasomatosis. It extends upward and widely into the Animike strata, taking all the forms above mentioned and finally constitutes, either wholly or largely, the fine gray irony quartzytes, and becomes intimately mingled with the black slates that charac- terize the Animike in some places. The presence of organic mat- ter, giving source to carbonic acid gas at the moment of the libera- tion of the silica has determined the condition and the color of the resultant siliceous rock.* This brings us to the consideration of 3. The carbonated iron group. This, as a source of iron ore in Minnesota is potential rather than actual, and it is here ranked on an equal scale with the forgoing because of its apparent great importance on the south side of lake Superior, especially in the Peaokee-Qjgebic range of Wisconsin and Michigan. Strati- graphically it lies below the jaspilyte horizon (No. 2 above) and apparently above the quartzose-hornblendic magnetite zone, or is wanting. This rock is represented by No. 312, and its chemical analysis, as reported by Prof. C. F. Sidener, is as follows :

Analysis of rock 312 (Chem. Series 215).

Silica 2 70 per cent.

Alumina 35

Ferric oxide. 17 . 23

Ferrous oxide 8. 35

Calcium carbona+e 49. 80

Magueeium carbonate 19. 65

Potassium oxide 04

Sodium oxide 20

Water 47

Total 98.79

According to this analysis there is a large percentage of calcium- magnesium carbonate in this rock. But in many places the rock seems to consist more largely of iron carbonate. Compare also Nos. 1306, 1307 and 1310 ; also 16th report, pp. 71 to 72. The outward appearance as well as the hardness and the readiness with which it is changed to ferric oxide, as evinced by the rusty Male that it bears all over the exterior when weathered, point to a considerable amonnt of iron carbonate. Of this rock bat few feet, (about 20) of thickness of strata have been seen, though there may be much more. If we may judge from the descriptions of Mr. E. D. Ingall, of the Geological Survey of Canadaf, the Animike for-

The new Mallmann mine, and the discovery of the Bros on Sec. 3, 58-18, both In hematite of this clans, and In the Taconlc rocks, are described at anot her place in this report.

Geological Surrey of Canada, Aunual report. 1887-88. Vol . III. Part 2, p. S3 II (Beport on the mines and mining of Lake Superior. 1888. )

122 Bulletin No. Vi.

mation farther northeast, in the Thunder Bay region, is very similar to the same in Minnesota in this respect. He states that the dolomitic portions, belonging in his "lower division," are only developed locally, although carbonates of lime and magnesia are distributed to- some extent through the whole formation. Toward the southwest from Gunflint lake, although they have not been discovered in Minnesota, owing perhaps to the general prevalence of the drift, it is highly probable that they increase in amount. At any rate it is plain that they constitute that part of the Animike formation which gave origin and sustentation to the theory that was advocated by Prof. R. D. Irving,* and more lately by Prof. CL R. Van Hise,t for the origin of the "Huronian" ores of the lake Superior region, and there seems to be no reason except the scarce- ness of these strata and their generally level position in Minnesota and Canada, why the same horizon might not develop, on the north side of lake Superior, an equal amount of merchantable iron ore of like kind and origin.

This rock is gray, or light-gray, on fracture, with chalcedonic, flinty and jasperoid inclusions, but on its weathered exterior it is rusty, as already stated. It weathers away rapidly, and the flinty inclusions project beyond the rest of the surface. Sometimes the pieces included in the carbonated matrix are large, i. e., several inches or a foot in their larger diameter, and they are placed in discordant positions against the lamination of the strata, and in other cases they are very small and even so fine that they can- not be seen easily by the unaided eye in the general gray of the fresh fracture. Again the flinty and jasperoid portions are inter- laminated in parallel bands in the calcareous strata as if so de- posited originally under the action of sedimentary agencies. J The siliceous fragments included in angular forms in this carbonated matrix manifestly must have been formed before the matrix that contains them. But the parallel and cotemporary formation of sheets of the same material within the matrix shows the continuance of the same cause and its interrupted action after the carbonated matrix had begun to be deposited. This siliceous material is un- distinguishable in all its essential characteristics, from that seen in brecciated condition, and in inter-leaved ribbons, in the jaspilyte beds of the Keewatin, but here the carbonated ingredient takes

Origin of the ferruginous schists and Iron ores of the Lake Superior Region. Am* Jour. Science, (3), XXXII, 255.

t The Iron ores of the Penokee-Gogeblo series of Miohlgan and Wisconsin. Am* Jour. Science. (3), XXXVII, 32.

Compare the original description of an outcrop on Gunflint lake, tenth annual re- port, p. 87.

Iron Obes Of Minnesota. 123

the place of hematite. The significance of this parallelism, in its bearing on the theory of the origin of the rock, and of the Animike ores of iron, will be referred to later.

Although the characters of the carbonated iron group are here described as belonging in their typical exhibition to the lower part of the Animike strata, it must not be understood that carbonates and carbon are wanting in the higher strata. The typical charac- ters are not always associated in the same stratum. Indeed, in the higher beds they are more frequently separated, or are dis- guised. Carbon is, however, one of the most common and wide- spread of the pronounced characteristics of the Taconio. Carbon- aceous slates, sometimes effervescent from carbonate of lime, make up a large part of the higher beds. Carbonaceous slates are inter- bedded with gray flint, the flint beds being from two to six inches in thickness (1277), but usually not far extended horizontally. Carbon in the form of graphite in pebbles and cakes from half an inch to an inch in thickness, is quite abundant in the metamor- phosed slates and quartzytes of Pigeon point (Nos. 270 and 552), and it is a common ingredient of some silver-bearing veins in the Thunder bay district (598). Some parts even of the quartzoae hornblendicmagnetite group are invaded by the ever present ele- ment (carbon). There is a rapid effervescence in hydrochloric acid when some of the actinolitic magnetites (437) are moistened by a drop from a glass rod. Thus, in the same manner that the chalce- donic silica seen in the jasperoid beds extends upwards in dis- guised forms, so the carbonated element, its associate in the car- bonated iron group, continues to be present throughout the Ani- mike.

4. The gabbro titanic-iron group. There is certainly no iron ore in Minnesota which is known to exist in larger amounts than this. The explorer in the iron regions is continually finding this ore in immense masses, and it has been the cause of many visits by intending purchasers. Fortunately the lithologic characters that surround it are so simple, uniform and evident that the tyro may discern them. The belt that carries this ore is wide, and it extends from Duluth to Pigeon point, constituting, in its culmin- ating topographic points, the summits of the Mesabi range.* The rook itself is gabbro, a basic eruptive, of gray color and generally

It should be noted that the grant tor ldgo, to which the term Mesabi is sometimes applied, it not the true Mesabi. but is known as tho Giant's range. Tho Mesabi hills are formed by the gabbro range, and lie from ten to twenty in lies south of the 0 hint's range. Compare 13th report, pp. 21 and 22. Tho Grand Murals Indians (Chip no was). hold a tradition that the great Riant, Membi. Is entombed In the hills north of Grand Marals, his head being represented by one hill, and his body, arms and legs being rep- resented by other spurs and subordinate ranges. These hills art* In the gabbro belt, and this traditional burial of the mythical monster Is sufficient to show to which hill range the name should now be given.

124 Bulletin No. Vi.

of coarse crystalline texture. Its minerals are labradorite, augite, magnetite, biotite, olivine. The relative amounts of these minerals undergo great variation. While perhaps in no case will any of them be found entirely wanting, over large areas, they are, sever- ally, sometimes so scarce, while at the same places some of the others prevail, that the rock takes on very contrary aspects. When the labradorite prevails, as about little Saganaga lake, and Bellis- sima lake, and in Carlton's peak, and in the feldspar masses that are embraced in the dark trap at Beaver bay, the rock when fresh is glassy, gray and firm, but on weathering it becomes almost white. When the magnetite prevails, as in the suburbs of Duluth, about the southern environs of Birch lake, at Iron (May hew lake), and many other places, the rock is black and firm, and simply be- comes specked with lighter spots on weathering, the spots indicat- ing the existence of crumbling crystals of labradorite. When the olivine or augite, or both prevail, which is apt to be accompanied by the appearance of crystalline masses of hornblende, and in cases of weathering near the water, the rock has a green or dark-green color, the green tint being increased by the conversion through weathering of some of these into serpentine, chlorite or delessite. In all cases of weathering the magnetite which constitutes the ore masses, and which nearly everywhere is to be seen in less quantity disseminated through the rock, is the most enduring of all the constituent min- erals. It forms the roughness that is apparent on the surface of exposed knobs of gabbro, and on the complete destruction of the rock its grains remain undissolved and may be seen gathered, in favorable places on the lake beaches, forming local deposits of titanic iron-sand. This gabbro is found associated with red syen- ite, quartz-porphyry and various sedimentary rocks in northeastern Minnesota, and, indeed, it passes through unimportant petro graphic changes into the well-known "traps" of the Cupriferous formation, from which it has not yet been possible to separate it by any important lithologic or stratigraphic distinctions.* In this red rock, however, which may be seen in great display about Brul6 lake and in the Misquah hills east from Brul6 lake, and in general about the headwaters of Brul<§ river, there is not known to be any important body of iron ore. Magnetite, however, as one of the petrographic ingredients is found scattered through it in small amounts — whether titanic or not is not known.

While the stratigraphic relation of this gabbro and its associated strata, to the Cupriferous formation may not here be discussed, its

See the Tenth Annual Report, p. 137. Typical thin sections of the rocks of the Cuprifer- ous series in Minnesota.

Iron Ores Of Minnesota. 125

relation to the other Taconic ores, as exemplified in northeastern Minnesota, is well known and can be expressed. It was supposed by the geologists of the late Wisconsin geological survey that the gabbro eruption, in the main, took place after the completion of the Animike strata, and that it formed the base of the Keweena- wan, fading off upwardly, by a succession of traps and sandstones, and with interbeddings of conglomerates and volcanic tuffs into the most characteristic features of the Keweenawan. This view has also been held by all the Minnesota reports except the eighteenth. But it has been found that the great gabbro flood of northeastern Minnesota was outpoured at an earlier date. In the sixteenth an- nual report* will be found evidence that it began during the de- position of the Pewabic quartzy te, and that it followed immediately after the body of that quartzyte had been laid down. This quartz- yte is believed now to belong at the bottom or near the bottom, of the Animike, although it was at first supposed to be the equivalent of the Potsdam (Paradoxides horizon) which apparently overlies the Animike. The gabbro being intimately associated with this quartzyte must follow it to the lower portion of the Animike, and hence to near the commencement of the Taconic so far as the Taoonic is developed in Minnesota. At the same time the term Pewabic quartzyte is supplied with a geological raison d'etre, since it is no longer possible to make it the parallel of that quartzyte which is supposed to overlie the Animike, viz: the Wauswangon- ing quartzyte, nor of any of its equivalents — whatever they may be. The gabbro, with its capriciously distributed titanic masses, therefore, being of about the same age as the non-titanic ore masses of the Pewabic quartzyte, and having been poured over the quartzyte, and having embraced large disturbed portions of the Pe- wabic quartzyte in its own mass, some of which might be turned up so as to stand nearly vertical,! will be found to present some confusion ' and variety as to the quality of the magnetic ore which it may hold. Such is the fact. It will not be safe to infer that because a magnetic ore body is contained within the general area of the gabbro it is therefore to be condemned as titanic, although that would generally be correct. It may be non-titanic and derived originally from the Pewabic quartzyte, or from some other part of the Animike, and it ought to be inspected carefully by one familiar with the distinctions between titanic and non-titanic ores, and as a final test it should be examined chemically for titanium. Such exotic magnetites within the gabbro can generally be detected by

'Pages 86, 88; 17th Report, pp. 52, 53; 18th Report, pp. 43-47. Seventeenth annual report, p. 96.

136 Bulletin No. Ti.

their having more or less quartz connected with them, or by some remaining trace of a sedimentary structure in the adjoined rook.

The structure of the gabbro is generally massive, rising in low rounded hills and spreading over a large tract of country. Oc- casionally a gueiasic (laminated) structure is seen in it Such oc- curs on the east shore of Birch lake where a conspicuous hill is marked by parallel weather-lines sloping toward the south, the Hues being due to the weathering out of the contained olivine which is disseminated in alternating sheets of greater and less pre- valence throughout the hill. It is shown in figure 15. The dip is

Fig. IS.— Bluff of gabbro having a gnelssio la ml cation.

42 degrees. Another recorded observation of a bedded condition of the gabbro is found in the tenth annual report (rooks 810 and 814), page 111, on the lake Superior shore two and a half or three miles east of Beaver bay. This gneisaic structure is not due to shearing pressure nor to sedimentation, but to a varying abundance of the more easily decaying minerals, such variation occurring in sheets and on the weathered edges appearing as depressed lines or grooves.

Since the gabbro in its petrographic characters apparently shades off into common doleritic trap, and into diabase, it is possible that it bad other epochs of outflow, and also that what is gabbro at ose place, at any stratigraphic horizon, may not be well characterized ' gabbro at another place. Hence there may be gabbro or gabbro- loid traprock, of much later date than the Fewabic quartzyte, and it may lie on any of the later strata of the Animike. Yet, notwith- standing this consideration, there is much evidence that the prin- cipal outflow of that coarse basic eruptive which is well represented at Duluth by the "Bice Point granite" or gabbro, and which is ac- companied by acid eruptive rock, whs of the age of the lower Ani- mike, and took place immediately after the Pewabie quartzyte.

(2) Microscopic characters of the enclosing Taconic rocks, (a) The rocks of group No. 1. The quartzose hornblendic (or olivin- itic), magnetite group.

Interbedded with the Pewabio quartzyte, at Chub lake, N.E. NE. Sec. 29, 65-4, are thin layers of basic materials ( 1339 ) which

Iron Ores Of Minnesota. 127

have the appearance of having been followed immediately by eoarser sediments of almost pure fragmental silica (1338). These two rooks were examined in thin section and described below. The origin of this basic material most have been quite similar to that of the green schists of the Keewatin, viz., volcanic ejection, and its dispersion due to the prevailing oceanic waters. Its nature shows its close genetic alliance with the schist that embraces the ores of the Keewatin.

Bock 1339. This is a compact lherzolyte chiefly composed of yellowish-green enstatite, olivine and magnetite, but presenting considerable variations, even in the same hand-specimen, passing from a fine schistose condition into a coarse crystalline (like noryte or gabbro) while in some of its modifications jt assumes the char- acter of a regular quartzyte. A section prepared from the dense, fine-grained schistose type shows an admixture of well defined tabu- lar plates of rhombic pyroxene (enstatite) of yellowish green color and granular or " fractured " olivine of a paler shade of green, with- out the yellowish tinge. The enstatite plates exhibit, in most in- stances, an exceedingly fine striatum, or division into parallel fibres; are comparatively free from cracks, and contain no enclosures of foreign minerals, except a few occasional grains of magnetite. They polarize in lively colors, (chiefly red and green) but show no pleochroism if tested with the lower Nicol, thus manifesting their essential difference from hornblende. The olivine is present in the form of angular masses and grains, and predominates over the enstatite. It is in a singularly fragmental or " shattered " con.di- tion, full of cracks, which do not appear as if due to the ordinary fissuration of olivine, (in its transition into serpentine) but to a cause which acted rapidly, such as mechanical pressure or a sud- den thermal disturbance. Cracks of this kind would be produced in glass or rock-crystal, if suddenly heated or immersed in cold water after heating. If the cracks in this olivine were due to ser- pentinization we would naturally expect them filled with chlorite or glauconite as necessary alteration products (as is invariably the case with olivine affected by serpentinization). Instead of this, the olivine fragments, though full of the usual enclosures ( glass - cavities,magnetite, picotite) are comparatively free from decomposi- tion-products and have retained their optical properties so well that the polarization colors are almost as brilliant as those of clear olivine.

The magnetite occurs in the shape of rounded grains and crys- tals, varying from dust-like minuteness to aggregates equalling in iie the largest of the enstatite tablets.

128 Bulletin No. Vi.

That an ultra-basic olivinoue rock like lherzolite should be found interbedded and in contact with quartziferous masses, and should actually pass into an unmistakable quartzyte, is, to say the least, remarkable.

Bock 1338. As one of the modifications, or local variations, of the basic type, described under 1339, this rock is peculiarly inter- esting. It is a well-characterized quartzyte, being composed of quartz-grains, magnetite and an interstitial substance of doubtful character, which may be altered muscovite. The quartz grains are mostly large and do not seem much waterworn, presenting angular outlines, though not as sharp and fragmental as in the Triassic sandstones. That they are part of the detritus of some ancient granite cannot for a moment be doubted as they haVe all the char- acteristics exhibited by the quartz of granites. They are full of fluid-cavities, which are usually arranged in lines, parallel, or nearly so, with one of the planes of crystalline growth. If we ex- amine these enclosures with a good i or inch objective we ob- serve in the smaller ones a lively vacuole-motion, while in the larger cavities the bubbles appear stationary. Beautiful yellow- ish dendrites of hydrated iron peroxide (as seen in moss-agates) are found here and there, lining the cracks.

The interstitial substance is not a mere amorphous pa&te, ce- menting the quartz grains, as one might be tempted to conclude, or an infiltration product, but an undoubted primary component, and in the writer's opinion, it was a constituent of the same gran- ites, which furnished the quartz. Its color is a yellowish-green, sometimes brownish, the latter indicating a more advanced stage of decomposition. It polarizes in remarkably brilliant tints of red, green and yellow, so that each quartz grain appears as if sur- rounded by a beautiful fringe of multi-colored ribbons. We notice the same peculiar banded structure in the muscovite of granites (also in sericite), and as neither hornblende nor any kind of rhom- bic or monoclinic pyroxene (especially if in the least decomposed), shows such intense polarization-colors, we may look upon this greenish, interstitial component as an original muscovite, rendered fibrous and stained by ferric hydroxide. The magnetite, of which this rock is largely composed, occurs in the shape of grains and symmetrical crystals, which sink down to dust-like minuteness ; some are wedged in between the quartz grains, others are enclosed in the latter. The crystals, grains and aggregates present well-de- fined boundaries, and not a trace of the usual hydrous decomposi- tion is observable.

The foregoing described samples( 1339 and 1338) were from near

Iron Ores Of Minnesota. 129

the bottom of the Pewabio quartzyte. The next (437) was taken from some higher quartzose strata on the Mesabi range, near the section line between sections 14 and 15, 59-14, at one of the old test-pits, opened by Prof. Chester's party. This specimen effer- vesces freely, and the carbonate present was supposed (in 1878, 9th report, p. 108) to be siderite. But it is quite likely that it is due to secondary calcite, as the effervescing is free on weathered surfaces, and feeble on fresh fracture. This is a common rock in the iron- bearing strata of the Mesabi range, ard it also occurs abundantly in the iron-bearing strata at Black Biver Falls, Wis., as well as in the Penokee-Gogebic range.

Bock 437. A grayish amphibolyte, which appears to be exclu- sively composed of actinolite and magnetite. The actinolite is characteristically developed in pale green fibres, which intersect each other at various angles, though never so as to give rise to dis- tinctly radial aggregates. The fibres show a very feeble pleo- chroism, but they polarize in lively tints of green, blue and yellow, especially in the clearer portions of the field. The magnetite is not evenly distributed in this rock, but occurs in nests or patches* each consisting of a dense aggregate of opaque granules, but iso- lated particles of magnetite are also noticeable among, or between, the actinolite fibres. The actinolite, there can be little doubt, is an alteration-product, but whether the parent mineral was ordinary hornblende, or one of its rarer analogues, cannot now be satisfac- torily established. The writer is inclined to consider it a modified tremolite, as it comes nearest to that mineral in its behavior be- tween crossed Nicols, showing stronger polarization colors and feebler dichroism than any other am phi bole variety.

The microscopic characters of the rocks that are associated with the impure jaspilitic-hemaUie-and-lhnoniie group have not been studied. They cannot differ very much from the characters indi- cated in the description of their megascopic features.

A single sample (312), representative of the third phase, the car- bonated iron group, has been examined in thin section. This was obtained from the north shore of Gun flint lake, where it acts as the matrix of a quartzyte and flint breccia, or conglomerate. (Ninth report, p. 82; 10th report, p. 87). Compare Nos. 1306, 1307 and

Book 312. A massive dolomyte of light gray color, with a faint

greenish tinge, homogeneous and compact in some of its samples,

while in others (1310) it assumes a porphyritic structure and

almost passes into a conglomerate, being intermixed with a dark

130 Bulletin No. Vi.

soft shale and with pebbles of greenish ohalcedonic silica. In the section prepared from the dense homogeneous variety (312) we ob- serve the usual granulation of massive dolomyte, the granules being entirely devoid of the striation invariably exhibited by cal- citefbut never by .a magnesian carbonate of lime. Many, if not most, of the granules are irregular in outline, flattened, fractured or pressed out of shape, but in numerous instances we still dis- tinctly observe the rhombohedral forms which are so persistently manifested by dolomite crystals, even when occurring in dense ag- gregates. The ohalcedonic masses embedded in this dolomite do not appear to fill or line original cavities and fissures in the rocks (which would imply a secondary origin), but seem to have been mechanically introduced during the deposition of the matrix. They have all the characteristics of water- worn pebbles, and it is extremely probable that the black slaty fragments (chlorite- schist?), noticeable in 1310, were likewise derived from a foreign source. All the structural features of this variable rock point to a period of considerable local disturbance during its formation.

The microscopic characters of the rocks of phase No. 4, thegabbro titanic-iron group are those that have been ascribed to the gabbros and the augite syenites of the gabbro series. They were described in a paper read before the American Association for the Advance- ment of Science at Cincinnati, *and have been more amply described and illustrated in Bulletin No. 2 of the survey, by Dr. M. E. Wads- worth. It is not necessary to dwell on them here. The titanic ore is one of the primary constituents of the rock, and is dissemi- nated through it in all relative proportions, only making ore where it exists so as to nearly exclude all the other minerals. Some- times the labradorite excludes all the other minerals in a similar manner, making a beautiful labradorite rock. Apatite, which is found uniformly in this rock in microscopic amounts, is another of the primary ingredients, and increases in amount in a remark- able manner, and probably constitutes, in Ontario, the extensive "phosphate deposits" of the so-called Laurentian, which have been supposed to prove the existence of organic matter in the Lauren- tian age, but which recently, Mr. E. Coste of the Canadian survey, has unequivocally assigned to its proper origin. (See the Biblio- graphy. )

(3). Structural features of the ores of the Taconic. As there are at present no productive mines in operation in the Taconic ores in Minnesota, there is not so favorable an opportunity to learn their structural features as there is for those of the Eeewatin. It

♦Proceedings, Vol. XXXf 1881, p. 160.

Iron Ores Of Minnesota. 131

be necessary , therefore, to confine ttys description to such ob- servations as can be made on the outcrops and excavations that have been visited, and the samples that have been collected. Some de- tails not here included will be found in the ninth, thirteenth, six- teenth, seventeenth and eighteenth reports.

The ores of group No. 1 — the quartzose- honiblendic (or olivinitio)- magnetiie group — are well characterized. They are in sheets that coincide with the dip of the nearly horizontal quartzyte beds that are associated with them, and their thickness, perpendicularly, appears not to be great; the greatest reported stratum being twenty feet thick. Sometimes several strata of iron ore are encountered, separated by quartzose beds, in which the ore is too lean to be of merchantable grade. The ore has a compact texture, brilliant lustre and closely perpendicularly jointed structure. The last makes it easy to break up into small angular, cuboidal or parallelopipedon forms. It also preserves a rude horizontal lamination (1308) by which the blocks acquire their upper and lower planes, due to the sedimentary structure implanted on it when it was formed. This is the character of samples obtained near the east end of Gunflint lake on Capt. Sedgwick's survey (Canada side). In some places contiguous, the ore is affected by olivinitic material slightly pyrit- iferous, and fades out gradually into a flinty-granular, yellowish, or often rusty, olivine (?) rock in which, while olivine is the chief constituent, there are evidently present also some pyroxenic min- eral, some magnetite, and some micaceous scales (1309).

At the ore locations a few miles west of Gunflint lake (on sees. 28, and 29, 65-4 W.) the quality of the ore is very similar to that just described, and it has the same structure and stratigraphic relations. It lies but a few feet above the gneiss of the Giant's range which runs east and west as a conspicuous hill-range less than a mile north of the outcrop, A shallow shaft that penetrated the ore at one point encountered this gneiss. The ore is inter-stratified with the fine gray (feldspathic? and) quartzose material that makes up so much of the lower part of the Aniinike, usually styled gray quartzyte, and seems to have this also as its principal admixed impurity. Curious black, amorphous, lenticular masses, somewhat flattened with the stratification, from half an inch to three or four inches in larger diameter, encroach upon the iron along certain of the sedimentary planes. At other times there is much coarsely crystalline horn- blende associated with the rock and the ore (452 H, and 453 H). Some of it is also strongly pyritous, the sulphide mingling with the magnetite and the quartz grains and having a light bronzy lustre suggesting the possible presence of nickel.

Bulletin No. Vi.

Numerous observation? have been made on this ore further toward the southwest, the details of which are given in the seven- teenth report, and need not be repeated here. Suffice it to say- that it seems to become olivinitic, especially in those outcrops- which lie nearest the bottom of the formation, and, in general, therefore, furthest north, and less hornblendic. These deposits are also the most important and more coarsely crystalline. Those iron strata that occur higher up in the formation are less valuable, bo far as observed. They are mixed, sometimes quite irregularly and capriciously, with siliceous rock material, and with fine- grained greenish siliceous bands. The magnetite winds out and in and crosses these siliceous parts, or it branches without any apparent reason or order. Fig. 16 was sketched to show this man- ner of the magnetite, seen in a perpendicular bluff of Animik* strata in N. W. sec. 24, 60-13, southwest from Birch lake.

Fig. 16.— Veins of magnetite in greenish Animike rook.

The magnetic quality of the non-titanic ores of the Taconic is known to extend but feebly as far west as the working of the Merritt Bros., sec. 3, 58-18, which is twenty-three miles west of the point where the Duluth and Iron Bange railroad crosses the Giant's range,

Iron Ores Of Minnesota. 133

and there is nothing known of it further west. It appears that there is a gradual change in the nature of the ore toward the south- west and west, as evinced in the strata of the Taconic (Animike), by which the magnetic quality is diminished, and that in place of magnetite the formation contains hematite and limonite. In some of the explorations that have been made in towns 59-14, 60-12 and 60-13, magnetite (with actinolite) and limonite are both found.

The ore that occurs in connection with the second group of lith- ologio characters — the impure jaspilitic-hematiie, and limonite group — is the Taconic analogue of the hematites of the Keewatin, and its original mineral associations, as well as its present struc- tural conditions, are essentially the same. The jaspilyte is con- torted and irregular. The silica is chalcedonic and parti-colored, but its colors are seldom (indeed never) seen so ribbon-like and ex- tensive. Bather the red appears as streaks or round follicular spots in the brown, or in the flinty silica. Also clear watery glob* Hies of transparent silica are distributed closely through a red jasper or a gray flint; or, vice versa, blood red spots the size of a pin head are thickly crowded in a pellucid matrix. These varia- tions are the noticeable features, and they coincide with the infer- ence that may be deduced from the comparatively small amount of this jaspilyte, to the effect that the force that produced this Taconic jaspilyte was of less duration than in the Keewatin and acted under conditions that cramped and interrupted its normal result At the east end of the Mesabi range, where the ores in this formation are, so far as known, all magnetic, this jabpily te contains a small amount of magnetite. In the central part of the range it cannot be recog- nized as jaspilyte in the ordinary use of the word, but it is a green- ish quartzose rock of very fine grain irregularly streaked with limo- nite; and at the west end (on Prairie river), with a development of typical banded jaspilyte, the associated ore is hematite. In an enlarged sense, however, the jasperoid element is found to pervade a great thickness of strata, and the limonitic beds of the central area may be said to occur in chalcedonic, greenish and yellowish silica that had the same origin as the red and gray banded beds at the ex- tremities of the range. These jaspilyte beds, especially those seen at the eastern end of the range, while in the main conformable in dip with the accompanying beds of the formation, are still more variable in small patches than those beds. They pass from horizontal to dips in diverse directions ( 1315 ). They have a fine fluid a 1 or "streamed" structure. This fine alternation is also visible often in strata higher up, in some magnetic black beds (362 H), the origin of which would hardly have been understood but for the information

134 Bulletin No. Vi.

and the results derived from this investigation. Those black banded magnetic siliceous beds graduate, apparently, on the one hand into the typical jaspilyte beds, and on the other into the greenish siliceous rock that is banded by limonite.

The ore of the carbonated iron group (No. 3) in Minnesota is at present entirely a hypothetical possibility. It seems to be that which is so largely developed in the Penokee-Gogebic range on the south side of the lake, and should it be found in Minnesota it is ta be supposed that a conjunction of circumstances similar to that described by Prof. C. E. Van Hise for Wisconsin would also be found. Briefly stated, there are three of those conditions which seem to be essential to the occurrence of ore of like kind and genesis on the north side of the lake, viz. 1. A considerable thickness of carbonated strata, preferably largely of siderite, but possibly of lime and magnesia. 2. A cutting of those strata by perpendicular eruptive dikes, the more numerous the better, pre- vailingly in one direction. 3. The tilting of the strata, with their contained dikes, in a direction parallel, or approximately parallel,, with the prevailing direction of the dikes. It would require, ac- cording to the theory of Irving and Van Hise, only the lapse of time and the continuance of natural meteoric forces to produce, along the troughs formed by the dikes and the strata which they cut, an accumulation and concentration of peroxide of iron through the change that would be wrought in the carbonates of the original Taconic strata. According to Van Hise's observations the valuable deposits of iron ore found in the Penokee-Gogebic range have this relation to the dikes and the strata, and will be found to run out or to be wanting entirely, on the lower or opposite sides of such troughs. We have no disposition here to question this hypothesis. We only wish to show where it is applicable in our classification and where it may possibly be identified. The Animike strata are highly tilted in the region west of Gunfiint lake and to Gobemiohi- gama lake, and perhaps in other places where they are covered by heavy drift deposits. Dikes occur generally, but they have not been noticed to bear that angle complementary to the dip which has been represented in Wisconsin. Should it be proven, however, that the Animike strata contain, near their base, a large body of carbonated iron, or of lime and maguesia, it is very likely that they will be found cut by dikes and changed as described by Van Hise. Further west in every place where these strata have been seen they are not so much tilted, but they might still be upheaved

♦Am, Jour. Soi. fd), xxxril, 32.

Iron Ores Of Minnesota. 135

enough to produce the necessary conditions for the concentration of the ores in such troughs.

[Since the foregoing was written two important discoveries have been made of hematite ore at this class. One is on Sec. 11, 59-14, and is known as the Mallmann mine. The other is on Sec. 3, 58-18, and is owned by the Merritt Brothers. At another place in this report the Mallmann mine is described and a generalized section north and south at the same place as shown in figure 26. The Merritt discovery shows a perpendicular thickness of ore of at least 27 feet, the southward dip being about 30 degrees. There is a little bluff of magnetic quartz schist about 150 feet to the north of the ore, and the ore probably overlies that. The gra- nite belt is about a mile further north, constituting the " hight of land." This deposit has been traceJ at least 1,000 feet east and west The downward succession in the strata appears to be as follows:

The great black slate formation.

Iron bearing rock, hematite.

Slate, grayish, some of it black, say 15 to 20 feet.

Quartzyte with magnetite ore.

Conglomerate.

Granite of the Giant's range.

This succession, and all the lithology, are repetitions of the Penokee-Gogebic iron range in Wisconsin. J

The gabbro titanic-iron group of lithologic characters has been described. It is only necessary to say here that the ore is a black, massive magnetite, generally of coarse, hackly crystalline fracture, and when pure and in large quantities, as it is frequently, it ap- pears in bold and bald knobs, and is dispersed irregularly through the gabbro of the Mesabi range.

It seems to be only a highly magnetited condition of the struc- tureless gabbro rock itself. This ore was first seen by the officers of the survey at Mayhew lake, north from Grand Marais.* May- hew lake is sometimes known as Iron lake. It is south from Gun- flint lake. A careful field-study of the appearance here gave origin to the following conclusions, from which we have not found it necessary to deviate in our subsequent study.

1. The ore is in the igneous rock.

2. It varies in quality very much, even passing into rock that cannot be styled iron ore.

3. It involves with itself nodules of coarse gabbro containing considerable magnetite (696).

Tenth annual . paw HO.

136 Bulletin No. Vi.

4 It also embraces isolated pieces of [gray quartzyte?] (698), but which in thin section are seen to consist of plagioclase, magne- tite and augite; and some dark crystalline micaceous nodules (697). [This is apparently a condition of the rock we have latterly styled muscovado."]

5. It dips toward the south in beds whose aggregate thickness is at least fifty feet, but may be seventy-five, the actual amount being hid by a swamp.

6. It involves, also, detached masses of coarsely crystalline gabbro nearly free from magnetite, but containing biotite.

7. It sometimes gives place to a coarse trap of the same kind which is so large in amount as to constitute the rock of the place, and its connection with the ore cannot be seen. Samples of this coarse micaceous trap are 699.

8. It lies on a fine-grained rock (700) like 698, containing chrys- olite, resembling a granular fragmental rock, whose apparent dip, due to a deceptive columnar appearance, is toward the north. (Compare 677).

This iron is in considerable but unknown quantity at this place, and appears in a similar manner in many places in the vicinity of Mayhew lake, toward the southwest and west, as well as toward the southeast This ore may also be seen in the gabbro within the corporate limits of Duluth, where it appears simply as a very highly ferruginous condition of the gabbro, with the other gabbro minerals as its impurities. There is no place within the area of the gabbro sheet where this ore may not exist, as its appearance is entirely fortuitous, but its quality varies from nearly pure magne- tite (or menaccanite) to simply magnetitic gabbro.

(c). Distribution of the Taconic . From the northeast the Animike formation enters Minnesota with a width on the in- ternational boundary of about sixty miles. The typical Animike strata are the slates and quartzytes, and the conglomerates that are developed in their basal portions. But the gabbro is of the age of the lower quartzyte, and that, and the other basic, interbedded traps, must be included in the formation as a whole. These rocks extend southwesterly toward Duluth and reach the Mississippi at Pokegama falls and at Little Falls. This general trend is divided apparently into two belts by a central anti-clinal of the older for- mations, the southern spur passing with the gabbro under the waters of the St. Louis river and bay at the west end of lake Su- perior, and becoming lost under the later lake Superior sandstones and only re- appearing (in Minnesota) far toward the southwest

Iron Ores Of Minnesota. 137

'where (at New Ulm) it emerges again and extends to the south- west corner of the state. The other spur, reaching Pokegama Tails, runs southwestward along the westerly side of the older anti-cline mentioned, as far south, at least, as Little Falls in Mor- rison county where it has an unconformable position on some Ver- milion mica schists,* and thence south weetwardly apparently fades -out by the general uprising of the granitoid rocks. Nothing very definite can be said of the boundaries of these spurs, owing to the Abundance of the drift-sheet, but this duplication of the strike of the Taconic strata is pretty well proven by isolated outcrops of this and the older formations which cannot be properly correlated in any other way.

(d.) Geological relations of the Taconic rocks. The reader will have inferred from the preceding description that the forma- tion succeeds the Eeewatin chronologically, and that it represents, in general, the time of the primordial fauna. There must have been a great improvement in the life-supporting conditions of the ocean, for, while there was still an occasional eruptive disturbance from which poured forth volumes of gabbro and other trap rock, there were still long periods of quiet during which life flourished. This is attested by the preponderance of carbonaceous slates, and the occurrence of carbonates of iron and lime and magnesia. An iron carbonate is the product of chemical precipitation in the presence of an excess of carbonic acid — otherwise the iron precipi- tate will be ferric oxide, as in the Keewatin. Organic matter is ordinarily required in order to extract carbon from the atmosphere -and store it in the rocks in any condition. If in the form of carbonic -dioxide it unite with lime or iron it may be precipitated in large quantities, in the bottom of the ocean, making important strata in the super-crust. If it be accumulated as free carbon, it will ap- pear as plumbago, or when impure as carbonaceous matter stain- ing the slates that contain it.

The Taconic strata in Minnesota are uniformly unconformable on the underlying rocks — whether of granite, greenstone, gray- wacke or mica schist. This observation is found to hold true from Thunder bay, in Ontario, to Little Falls and Pipestone in Minne- sota, f and generally their dip is less than twenty degrees.

(e.) Nature and origin of the Taconic ores.

The ores here embraced in the Taconic Animike] are of three kinds, viz :

This Ih the first announcement of this unconformity at Little Fall*. It will bo studied more fully and reported later.

♦In this statement the Sioux <|iiart/.yt* may be considered the equivalent of Mia Pewabio quartzyte but we do not e.uiil'dertliat equivalence 1- established.

138 Bulletin No. Vi.

Black magnetites from the Pewabio quartzyte. Hematites (often limonitic) from the jaspilitic beds. Titanic magnetites from the gabbro. These are all found in the Mesabi range.

Of these the first is the most promising for a supply of ore for use in the immediate future. The second is the lithological Ta- conic representative of the Eeewatin hematites and the exact parallel of the Gogebic hematites, and the third is known to occur in the greatest amount.

Chemical Composition. Following are chemical analyses of the Pewabio magnetites :

From N. W. sec. 23, T. 65-4. (west end of Gunflint lake).

( By Battle and Nye, Cleveland.)

Metallic iron 65.600

Silica 10.020

Phosphorus 0.042

Manganese 4.340

Alumina 0.340

Titanium None.

From N. E. }iN.E.\i sec. 29, 65-4. (west of Gunflint lake).

(By Rattle and Nye, Cleveland.)

No. 1. No. 2 No. 3..

Metallic iron 58.40 54.01 63.98 (average of 6 samples)

Silica 8.22 9.37 8.90 "

Phosphorus 0.36 0.32 0.28 " "

Manganese 4.92 5. 02 none " "

Alumina 52 .07 " "

Titanium none none trace " "

From N. E. M sec. 23, 60-13. (near Iron lake).

(ByO. P. SJdener.)

Silica U.W

Alumina 34

Magnetic oxide of iron 87. 00

Lime 20

Magnesia 80

Titanium none

Phosphorus 056

Sulphur trace

Metallic iron ' 63.07

From 8. E. )4 sec. 30, 62-10. (Transported masses in gabbro).

(By 0. F. Sldener.)

Silica 11.

Alumina traces

Mag. oxide of iron 85.55

Titanium none

lime 22

Magnesia 3.44

Phosphorus 02

Sulphur trace

Metallic iron 61.95

Iron Ores Of Minnesota. 139

From the new discovery of the Stone Iron Company 8. W. J£ sec. 18, 59-14.

(Two miles west of Mallmann's oamp). (By Rattle, Nye and Hollls, Cleveland.) Analysis of a blended mixture of hematite and magnetite.

Peroxide of iron 78. 01

Protoxide of iron 11 .07

Silica 10.17

Phosphoric acid 038

Manganese trace

Alumina trace

Lime 38

Magnesia trace

8ulphur trace

Organic volatile matter trace

Titanic acid none

Total 99.668

Metallio iron 63.21

Phosphorus 017

Several other determinations have been made of the iron in the ore of this age, and in all cases there is found in it no titanium. Such was found to be the case in samples from Sees. 30 and 31, T. 62-10, and Sec. 24, 61-12, and at several other places.

The mineral impurities are chiefly combined in the forms of quartz, olivine and hornblende, and occasionally biotite and pyrite.

Following is analysis of the jaspilitic hematite from Prairie river. This is the only place known where this ore appears in a typical form. At points further east it becomes first limonitic, as at Griffin's and Mallmann's camps, and then apparently magnetitic, as at the north shore of Gunflint lake. Indeed, it appears that the- condition of the iron oxide is a matter of little importance, in con- sidering the jaspilitic ores. When the ore is magnetic the general colors of the jaspilyte are dark, but with lamina) of white quartz. When it is hematite the blood red jasper is most characteristic, and when it is limonitic there is with the limonitic streak a soft- ened tint of gray with yellowish and greenish shades in the sur- rounding siliceous rock. In general, however, it appears that the magnetitic belt underlies the hematitic.

Hematite from Prairie River rapids, 8. E. H sec. 34., T. 66-25.

(By Prof. J. A. Dod**'.)

Silica 8.25

Alumina traces

Peroxide of iron 92 . 08

Lime truces

Magnesia traces

Phosphorus .09

Sulphur .01

Manganete none

Titanium none

Metallic iron 64.45

Bulletin No. Vi.

Hematite from Qriffln's Camp, sec, 22, 56-24.

(By Prof. J. A. Dodge.)

Chemical Series 210.

Silica, Si O, 3 . 62

Alumina, Al, O, trace

Ferric oxide, Fe 8 Oa 95 . 76

Lime, Oa O trace

Magnesia, Mg O trace

Phosphorus, P 098

Sulphur, S none

Manganese, Mn none

Metallic iron

From Sec. 20, 59-14. (Mailman's camp, on the Duluth and Iron Range

B. R., now the Stone mine.)

Silica. 3.62

Sesquioxide of iron 87. 10

Manganese trace

Lime and magneeia trace

Phosphorus 028

Sulphur trace

Water 9.70

Metallic iron.

From N. W. quarter, Sec. 20, T. 60-12. (Works of Peter Mitchell.)

(By A. H. Chester, Clinton, N, T.)

No.l.

No. 2.

No. 3.

No. 4.

No. 5.

Silica

trace.

Alumina

Lime h .

trace

Sulphur

Phosphorus.

Oxygen with iron

From the Mallmann mine. (S. H 8. £. Sec. 11, 59-14.) Sampled by A. J. Trimble. Analyzed by John I. Souther, Hurley, Wis.

No.l.

No. 2.

No. 3.

Silica

trace

trace

Lime

trace

Magneflia

absent

absent

absent

[ .016

Titanium

absent

absent

absent

Iron Obe8 Of Minnesota. 141

Of the gabbro magnetite many analyses have been made. The following will be sufficient to show the composition of this ore.

From S. E.%9 Sec. 36, T. 65-3 W. (Iron lake).

(By R. S. Robertson, Pittsburg).

Silica 2.02

Alpmina 2.68

Titanium 12.09

Seequi-Chromium 2.40

Magnetic oxide of iron 80. 78

Lime trace

Phosphoric acid 03

Metallic iron 5848

From Sec. 86, 63-10. (By 0. F. Sldener.)

Silica 11.87

Alumina — 1 . 82

Magnetic oxide of iron 63.33

Protoxide of iron 14.42

Oxide of titanium 16.03

Lime 10

Magnesia 2.73

Phosphorus 01

Sulphur trace

Metallic iron 49 .' 40

From Sec 86, 65-8 W. (Iron lake).

(By Prof. J. A. Dodge.)

Silica 20.90

Alumina 1. 75

lame trace

Magnesia 2.63

Titanium binoxide 2.23

Phosphorus none

Protoxide of iron 2.01

Magnetic oxide of iron 70.29

Metallic iron 52.' 46

The iron sand on the beach (Sur. No. 126) near Beaver Bay is derived largely from the decomposition of titaniferous gabbro, as is shown by the following analysis:

Iron sand from Black beach, near Beaver Bay.

(By J. A. Dodtfo and F. Sldener).

Silica 65.17

Magnetic oxide of iron 80.06

Protoxide of iron 2.23

Dioxide of titanium 2.48

lame trace

Magnesia trace

Alumina trace

Metallic iron 2350

142 Bulletin No. Vi.

Iron sand from .8 W. )£, Sec. 33, 61-12. (South shore of Birch lake.)

(By Prof. J. A. Dodge.)

Silica 5.19

Alumina 2.95

Lime trace

Magnesia 0.35

Phosphorus none

Titanium dioxide 36.77

Metallic iron 41. 12

The use of titanic ores. The present disqualification of titanic ore for use in making iron keeps these deposits in comparative disrepute. There is no mining of them now going on in Minnesota. The percentage of titanium, even when small, is considered fatal to any effort to introduce them into the furnaces of the country. A low percentage of titanium, however, (three or four per cent), if it could be maintained at a low stage, should not debar these ores from present use, and it probably would not if there were not so large and ready a supply of non-titanic ore. We may safely pre- dict that at some time in the future these titanic deposits will be found useful and valuable.

The difficulty that has to be met in the use of titanic ore pertains not to its low grade in iron, nor the presence of phosphorus or sulphur, but to the chemistry of its metallurgy, by which a consid- erable amount of the iron is lost in the slag, and by which the throat of the furnace becomes sooner obstructed with refractory accumulations. Titanic ore makes a superior iron, the small amount of titanium that remains in the product giving the iron greater hardness and firmness, enabling it to stand greater wear. The iron is also well adapted for making steel. The loss that is occa- sioned by the smelting of titanic ores, is due to the fact that the 44 only solvents of titanic iron are the double silicates of iron and lime, or iron and alumina and lime, or iron, potash and lime, etc," and as these constitute a part of the slag that runs from the fur- nace, they carry away a percentage of the iron, and the loss is greater in proportion to the amount of titanium it is necessary to remove.

Quite recently a process has been employed for reducing titanic iron ore which obviates the loss suffered by the common furnace process for hematite and other magnetites.

"A paper recently read before the American Chemical Society gives some interesting facts concerning the successful smelting of iron ore containing high percentages of titanium. This element has generally been held in disrepute by American iron masters, and they have gone so far as to say that the result of their experience has been that a mixture containing a greater percentage of titanic acid

Iron Ores Of Minnesota. 143

than 1.25 per cent, could not be successfully used. When present in greater quantities, titanium has a tendency to render the slag pasty, and clog the furnace with titanium deposits if it is not made by judicious treatment to pass into the slag. On this account many deposits of titanif erous iron ore have been neglected as of no value, although such ores are apt to be very free from phosphorus and are therefore especially suitable for Bessemer iron.

In Sweden and Norway, however, ores containing from five to ten per cent of titanic dioxide have been smelted alone in charcoal furnaces, others containing from fifteen to twenty per cent or more have been smelted in admixture, or even alone, and, lastly, Norway ores containing as much as forty per cent of titanic dioxide and only thirty-six per cent of iron, have been smelted by a com. pany in England with perfect success, as far as the metallurgy of the treatment was concerned, although at considerable expense for

fuel.

The successful treatment of these titaniferous ores depends en- tirely on the choice of fluxes to obtain a desired result. Certain natural compounds of titanium, such as sphene, calcium silico- titanate and keilhauite, are perfectly fusible in a blast furnace, and the composition of the slag run from the furnace should be made to approximate in composition these natural compounds. The fol- lowing is the analysis of ore which has thus been successfully smelted in a Norway ilmenite.

Titanic acid, 39.20 per cent.; ferric oxide, 18.59 per cent.; ferrous oxide, 30 00 percent.; alumina, 2.89 per cent.; manganese oxide 0.60 per cent; silica, 5.70 per cent.: loss 0.22 per cent.; iron, 36.3 per cent.

The following was the composition of the slag, compared with natural sphene:

Slatf. AviTiitfc sphene.

Silica 27.83 31.78

Titanioaoid 36.18 40.00

Lime 24.36 24.59

Oxideofiron 1.86 2.00

Alumina 9. 18 2.00

Magnesia 0. 60 2 . 0U

All the titanic acid of the ore has been made to pass into the the slag, excepting the small percentage left in the pig metal, per- haps one or two per cent."*

When it is considered that within the Mesabi range of Minnesota there are enormous amounts of titaniferous iron ore which have been ignored in the rush for the non- titaniferous, and that with the exception of the Adirondack region of New York, no other so

The Engineering and Mining Jo urn al. New York. July 5. 1S00.

144 Bulletin No. Vi.

large deposits of such ore are now known in the United States, it is reasonable to expect that, in the light of the foregoing descrip- tion of a new process, the iron industry of the state will long enjoy a flourishing condition.

Origin of the Taconic ores. The reader who has pursued the foregoing descriptions will probably have discovered that we re- gard the ores of the Taconic, so far as they promise economic re- sults of importance in Minnesota, as having two different methods of genesis ; also that there is reason to look for the discovery of ore deposits in Minnesota of still another method of genesis.* We see no reason to exempt the Taconic ores from those methods and principles that we have found obtained in Keewatin time. We see on the other hand only evidence to convince us that the Taconic ores date from the origin of the rocks themselves, and that the con- ditions that governed the origin of the rocks weie but a modifica- tion of those that governed the accumulation of the Keewatin rocks. Those modifications consist in a considerable abatement of the vol- canic forces and ejections, and the presence of organic matter. Chemical reactions took place under the same changes in the oceanic waters as before. Chemical silica was precipitated and was alter- nately, or confusedly, interstratified with precipitated iron oxide, forming Jaspilitic masses and strata. These were covered by materi- als accumulated by more common methods of sedimentation, but were often also buried under materials that were of almost imme- diate eruptive nature. The Pewabic quartzy te in its coarser parte, is not made up of chalcedonic silica, but in its finer portions it is almost wholly of chalcedonic silica. Whether its coarser parts- were at first coarsely fragmental, and comparable to the St Peter sandstone, as is probable, or were finely granular in the manner of the silica of the jaspilyte, we are not prepared to judge. We find it a compact, almost vitreous, though granular, quartzyte, and through it run, in the vicinity of the gabbroitic beds, hornblende crystals and coarsely crystalline lumps of basic minerals that cer- tainly are of secondary origin. In the presence of such changes, and of such an agent of metamorphism as the gabbro overflow we may infer that, whatever the condition of the pure silica at first, it has been largely changed and consolidated.f But that the iron that is involved with it was coeval in origin with the quartz itself

♦Since this was written, there have been two discoveries of Iron ore In the Mesabi range which Illustrate In the same manner, apparently, as the ore of the Penokee- Gogeblc range, the third method of genesis referred to: viz. the ore at the New Mall- man n mine and that of the Merrltt Brothers. These are situated in towns 50-14 and 58- 18, and are described In other places in this bulletin.

tMr. E. D. Ingall (Annual report, Oan. Geol. Sur. 1887-8, p. 81 H) thus describes these siliceous fragmental rocks: " They are seen to have been fragmentary rocks consist-

Iron Ore? Of Minnesota. 145

there is no question. Therefore we place in one category —viz., chemical oceanic precipitation — the quartzose- hornblende (or oli- vine) magnetite ores and the impure- jaspili tic hematite (or limo- nite) ores.

It is still quite possible that the magnetite which is found dis- seminated through the Pewabic quartzyte, especially in its more coarsely granular parts, may be assigned to oceanic fragmented accumulation. This seems the more probable from the fact that the quartzyte grains themselves appear to .have had that origin in part.

The gabbro magnetic ore we consider an integral part of the eruptive gabbro. Its intimate association with the minerals that constitute the rock, when it exists in large masses, and its almost universal dissemination in crystalline form, and in various degrees of abundance, throughout the gabbro sheet from Duluth to Pigeon point, will admit of no other hypothesis.

That the Taconic in Minnesota was an age of animal life in the ocean is indicated not only by the carbonaceous character of the black slates, and by the recent discovery of traces of fossils in the Thunder Bay region, but also by the presence of considerable beds of the carbonates of lime, magnesia and iron.* These have long been known. They were described briefly by Logan and by Bell. That they are a portion of the original rock strata, and that their origin dates from the origination of the Taconic as a forma- tion, it seems to us can hardly be questioned. They appear to be due to the chemical precipitation of the salts of lime, magnesia and iron in presence of an excess of carbonic acid. The curious mix- ture of lumps and somewhat angular pieces of chert, jasper and jaspilyte in these beds, when the beds themselves are not purely sedi- mentary products, may be referied to the same causes as operated in the breaking up of siliceous strata in Keewatin time, and their quick transportation to new places and their burial under freshly

lag of rounded audsubangular fragments which have been subsequently changed very much by the deposition of Infill ration products around tlieir constituent particles, th Ik action haying gone ho far. sometimes, us to change the particles themselves and almost entirely obliterate them." We wish tn dissent, however, from his explanation of the oceurrenco of the dolomltic beds In the Taconic. and especially from his Idea of the origin of breccias (p. KJ, il ). which he states in these words: "The crystallizing power of the carbonates ha- broken these port ions into fragments which have thus got dis- tributed through the mass In nucha manner as to form breccias, etc." and from the whole Idea of secondary "slllcllicatlon" and "dolomilization." which he adopts. apparently, from the writings of the late Prof. K. I). Irving.

Messrs. Rattle. Nye and Hollis reiiort a trace of volatile organic matter discovered by analysis in the magnetic on' of the Taconic from the recent discovery on See. ]s.

146 Bulletin No. Vi.

accumulated deposits of the ocean, whether of ordinary sedimenta- ti6n, chemical precipitation or volcanic eruption.

We are quite ready at this time to adopt the theory that has been referred to, originating with Dr. Edward Hitchcock, and more re- cently adopted by Prof. J. D. Dana and Prof. E. D. Irving, that these carbonated beds may be changed, and have been, on a large scale in the Taconic rocks of New England and of the Penokee- Gogebic range, by infiltrating waters, that their alkaline constitu- ent has been carried away and their iron has been redeposited or concentrated in a residual condition as ferric oxides, and that by this concentration large beds of iron ore have been formed. It is because of this that we state our belief that possibly important beds of limonite or hematite, originating in this way, may yet be found in the Taconic region of Minnesota, the parallel of those that have recently been opened up in northern Wisconsin. While we give assent to this theory we desire to say, still, that we have not suffic- iently studied the facts in the field on which it is based in Wiscon- sin, to warrant us in having an independent opinion,! and that our acceptance is based on the descriptions of Messrs. Irving and Van Hise. We do not believe, however, that the process of concentra- tion of the iron, was preceded, nor accompanied, nor followed by any such process of "silicification" as Prof. Irving urged. We believe the chert and jasper, mixed with the "cherty carbonates," were indigenous, and were the result of chemical precipitation from the waters of the Taconic ocean. " The beds and masses of chert, flint, hornstone and many jaspers, have all apparently been depos- ited from aqueous solutions." (Hunt in Geol. of Canada, 1863, p. 574.)

(/) Probable parallels of the Taconic ores in other parts of the United States.

There is no question in our minds as to the correctness of the parallelization which Prof. A. H. Chester adopted. He called at- tention pointedly to the similarity of the rocks and general geology of the Mesabi and the Penokee ranges.*

In all respects except the nearly horizontal bedding, the Mesabi district is precisely similar to the Penokee region of Wisconsin, and a person familiar with the latter cannot fail to notice the close resemblance. Here are the same

tAn obstacle to the acceptance of the theory of the origin of the Penokee-Gogeblc ores as expounded by Prof. Van Hise. (Am. Jour. Sci., Ill, Vol. , p. 32), has lately come to light, viz: large deposits of hematite are found in the strata below the points where they are cut by the eruptive dykes, and hence below the bottom of the trough whose existence was supposed to be necessary for their accumulation. This has been developed at the Oolby mine. Unless there should prove to be a second dyke forming a second trough below the other, it is hard to see how the lower ore deposit can be accounted for on this hypothesis.

♦Eleventh report of the Minnesota survey p. 150.

Ikon Ores Of Minnesota. 147

magnetitio quartz schists, hornblendio magnetitic schists, dark and light gray quartz-sohists, arenaceous gray and white quartzyteb, and other similar rooks; and especially here is the same apparent substitution of quartz and magnetite tor each other . The writer pointed out this resemblance in his report on the Mesabi district, presented in 1875, and is now [i. e. in 1880] clearly of the opinion that the iron-bearing rooks of this district bear the same relations to the Huronian series as do the rooks of the Peookee iron range in Wisconsin.

This opinion has been borne out fully by subsequent examina- tions, almost without exception. But there has not yet been found in the Taoonic rooks of the north side of lake Superior any iron deposits that are the parallel in quality and abundance of those found on the south side. The ores that characterize these strata in Minnesota, so far as they seem to be valuable, are magnetic, and indigenous in the strata, They exist in this condi- tion also in Wisconsin — particularly in the western portion of the Penokee range, and at Black River Falls — but they have not been brought into successful economic development. The Taconic gab- broore (titanic magnetite) is peculiar to Minnesota,so far as known, in the northwest.

In Michigan there is strong probability that the Taconic changed ores exist at Negaunee in intimate association with the Keewatin ores, overlying the Keewatin strata unconformably. We would refer specially to the mines situated in the eastern environs of Negaunee, the Buffalo, Sam Mitchell, Queen, Boston and Iron Cliff, as the most probable representatives of the Taconic ores of Minnesota, the Jackson mine being undoubtedly in the Keewatin.* At Isbpeming we think also that the Taconic ex- ists, and that it supplies the ore taken from the principal mines. The Taconic strata here seem to be unconformable on the Keewa- tin (the so called dioryte) and also unconformably overlaid by a great quartzyte and conglomerate formation. (Compare the 17th and 18th reports).

In the area of the original Huronian are no active iron mines bat some important known iron ore deposits which are presumably in the Taconic. f Owing, however, to the probable confusion of two unconformable formations under the term Huronian by the later Canadian geological reports, it is impossible to form a reliable opinion of the age of any of these ore deposits. The descriptions of some of them seem to indicate that they are in the Keewatin, in-

Prof. Chester seems to have found on the Monabi range a similar proximity of Keewatin J as pill tic ore to magnetic on? of the Taeniilc-- Minnesota eleventh annual report, p. 158,

tSee the Seventeenth annual report, Minnesota survey, for reasons for placing the Huronian on the geological horizon of the Taconic. See also American (icoloyM, vol. yI., p. 880, "Recent Observations on Some Canadian Rooks." A. Winehcll.

148 Bulletin No. Vi.

stead of the Taconic, and this is specially true of that on the N. W. portion of the Wallace mining location, which is apparently embraced in the Missasaugui quartzyte. (Compare the 18th Min- nesota report.)

Still farther east, the so-called anorthosite rocks of the Canadian geologists, containing large quantities of titaniferons iron ore, placed by them at first in the Laurentian, are unquestionably the parallels of the Minnesota gabbro belt with its associated sy- enites and schists. In Minnesota this eruptive is not so complicated with the rocks that it invaded that it cannot be studied satisfac- torily and its age has been found to be that of the Pewabic quartzyte, the base of the Animike. This ore occurs in Canada at Bay St. Paul, at St. Jerome and Bawdon, and other places.

In northern New York, titanic iron ore is found associated with the " Hypersthene rock" of Emmons, and it has been extensively mined. 1 his "Hypersthene rock" is the exact mineralogical parallel of the " anorthosite rocks," as well as of the gabbro rocks of the Me- sabi range of Minnesota. Even the iron ores that it furnishes are titanic. Mr. E. Coste, of the Canadian geological survey, having studied the Archean apatite deposits has recently come to the con- clusion that they are also of eruptive origin. These are found in the same mines with the magnetic ores, and he infers that they are eruptive.* This conclusion may be correct for the Labradorian (anorthosite) Archean, in which the magnetic ore is apparently al- ways titaniferous, and which is really of primordial age ; but the non- titaniferous magnetites of the Archean of Canada, New York, New Jersey and Pennsylvania are plainly interstratified and of sedi- mentary origin structurally, although their enclosing rocks may have been derived from sediments that were of eruptive origin.

The report of Mr. C. E. Hall on the magnetic ores of New Yorkf is a valuable contribution to the literature of the iron ores of the coun- try. It indicates the presence of a great quartzyte, iron- bearing, formation, producing "sulphur ores", overlain by a crystalline lime- stone, and higher still by the "upper Laurentian" with its titanic ores. This brief report describes the limestone as unquestionably unconformable on the lower Laurentian. Judging from our studies in Minnesota we are inclined to believe that in northeastern New York will be found the eastern representatives of all the iron- bearing formations of the northwest, with the possible exception of the characteristic Keewatin with its jaspery hematites. We cannot forbear to suggest that the quartzyte that bears the "sul-

' *Geol. Sur. Can., annual report, 1887-88, part S.f pp. 62-64. t Report of the State Geologist of New York for 1883, p. 23.

Iron Ores Of Minnesota 149

phur ores" is the Pewabic quartzyte of Minnesota, the uncon- formable limestone is the cherty carbonate horizon of the north- west and that the titanic magnetites are the gabbro titanic ores of the Mesabi range. It seems that the normal condition of the Taconio limestones is better preserved as limestones when they have been greatly disturbed by upheaval, and subjected to com- plete crystallization. At least in Minnesota and in northern New York they do not yet appear to have been converted to ferric oxides on any important scale, comparable to the change they have suffered in the Penokee- Gogebic range.

Further south, however, in eastern New York, the carbonated strata of the Taconic seem to continue and to have been the cause of much of the iron industry in several counties. It is true that Prof. Dana, and more recently Prof. J. P. Kimball* have assigned these ores to the Hudson River epoch, but we think that such a conclusion is not beyond doubt There is no question that in New England, and even in the Taconic region, there is a primordial limestone immediately overlying a primordial quartzyte. Such is reported by Mr. C. D. Walcott. If it is what we suppose it to be it is the equivalent of the limestones that we have found in Min- nesota, and Irving and VanHise in Wisconsin, converted more or less to manganesic hematites and limonites, and hence the repre- sentative of our "cherty carbonates." Indeed Prof. It. D. Irving made pointed reference to these sideritic ores in comparison with the Penokee- Gogebic ores, when he adopted finally the theory of their origin from carbonates.f The objection to their beiug of Taconic age is their supposed parallelism with some limestones in which Cambrian (i. e. Trenton) fossils have been found. But so far as we can find out there is no instance of Cambrian (Trenton) fossils being found in the limestone with which the ore is im- mediately associated. The ore belt is represented in Vermont as lying immediately above the "granular quartz" just on the west- ern foothills of the Green mountains, in a limestone which would necessarily pass below the Taconic mountains. This limestone occupies the same stratigraphic position further south, through- out its extent. Prof. Dwight states that "the Olenellus quartzyte and the Olenellus limestone rest upon the gneiss of Stissing mountain." (Am. Jour. Sci. (3), , 140.) This is the lime- stone which is represented on the map of the geology of Dutchess county by Prof. Dana as extending to Copake where it sustains

*Aru. Jour. Science, (3). XIV.. 132; mid XL. 155.

+Am. Jour. Science, (3), XXXII, 270. Prior to Irvintc Prof. J. D.Dana and Dp. Edward Hitchcock had arrived at the sumo conclusion an to the Hudson valley sldor- ltes. Geology of Vermont. Vol. 1. p. rati.

150 Bulletin No. Vi.

the Copake Iron Works, (Am. Jour. Sci. (3), xvn, 379), and which in his descriptions he has considered an extension of the Wappinger Valley limestone in which Prof. Dwight has found Trenton fossils east from Poughkeepsie. According to Prof. Dwighfs description these two limestones can hardly be dis- tinguished lithologically, but they occur in closely related regions and almost in contiguity, confusedly faulted and abutting now against the Hudson River shales and now against the primordial. Fossils being abundant in one and very scarce in the other there is a natural disposition on the part of the field geologist to follow the guidance of the last discovered fossils as far as he can, or un- til some other evidence takes its place or contradicts it In this way, perhaps, the influence of the Cambrian (Trenton) fossils has had too wide an application. This would be still more natural in the hands of an observer who entered the field with a predisposed mind toward the exclusion of all Taconic strata from the Taconic region. It is not too much to say, therefore, that while there has been a disposition on the part of geologists to follow the con- clusions of those who have worked on the Taconic area and especially Prof. Dana, even to the cancellation of primordial strata in the Taconic area, there has been an evident inclination on the part of Prof. Dana and his colleagues to augment the evidence un- favorable for the Taconic and to neglect that which might be favorable. At any rate, for the purposes of this paper it will be justifiable to follow the general evidences of parallelism that exist between the eastern and western Taconic, and to call attention to the ores of western New England as the equivalents of the Mesabi and the Penokee-Gogebic ores of the northwest. The belt of limonitic iron mines of western New England passes further . south, into eastern New York, thence into New Jersey and Penn- sylvania where it is well known. Indeed it becomes one of the characteristic features of the Appalachian range of mountains through Virginia and into northern Georgia ; and inferential therefore we are obliged to extend the Taconic strata along the Appalachian mountains across the eastern portion of the United States.

[See Appendices B and C for a further discussion of the eastern parallels of the Taconic ores.]

Iron Ores Of Minnesota. 151

(4). The Limonites Of The Cretaceous.

The first mention of iron ore belonging to the age of the Cre- taceous in Minnesota was that of B. F. Shumard,* although he simply mentioned the existence of " nodules of oxide of iron and argillaceous iron ore," having a thickness of two feet, and thought it might piove to be extensive and readily accessible. This was in the valley of the Le Sueur river. He did not refer it to the Cre- taceous age. In 1873 the Minnesota survey was carried over the same region and some further notes were made on its manner of occurrence. (Second annual report, pp. 133, 179, 203). The same ore was. noted later overlying the Galena limestone in Fillmore county f, and associated with Cretaceous deposits. The discovery was made by C. C. Temple in digging a well near his (Cretaceous) sand pit, and the interesting description by him is eesentially as follows:

He testifies that this bed of iron ore is at least thirty-six feet in thickness. In his well, which is six feet in diameter, and circular at the top, he dug down about eighteen feet when he reached rock, fragments thrown out revealing the Oalena limestone. He de- scribes the rock as occupying about one-half the diameter of the shaft he was digging, which afforded great quantities of soft limo- nite or ochre. He drilled into the iron a depth of thirty-six feet. A number of wells in the vicinity of Etna, a few miles further southeast, also struck a similar iron ore, and in other places in the same county considerable pieces of spongy limonite (not bog ore) have been found in the fields, having been discovered by plowing.

Traces of apparently the same limonitic deposit, occupying about the same position with respect to known or hypothetical patches of Cretaceous, have been met with in several counties further east Curious nodules of limonite, apparently pseudomorphous after marcasite, are found lying loosely on the tops of the wind-worn bluffs along the Mississippi river, among fragments of siliceous rock and of quartz. Sometimes it is in coxcomb aggregations, and sometimes irregularly spreading and hepatic in outline, or botry- oidal or mammillated. Such limonitic debris is also found at the Cretaceous locality in Goodhue county, about eighteen miles west of the Mississippi, where clay for pottery is obtained, and on the

Owen's report on Wisconsin, and Minnesota, p. 487. '♦Fourth iinnual report, p. S8.

152 Bulletin So. Vi.

weathered bluffs of the same county further east. It has come to be recognized as one of the evidences of the former extension ot the Cretaceous strata further east over areas where they do not now exist. Limonitic nodules and fragments of crusts occur in the blue-clay drift in all places where the presence of the underlying Cretaceous is known. They are often mingled, as at Lime Springs, Iowa, with pieces of Cretaceous shale, and even, sometimes, with determinable Cretaceous fossils. These evidences of the Cretace- ous have been found in Winona, Wabasha, Goodhue and Dakota counties, and they imply that the Cretaceous must have once stretched across the Mississippi valley into Wisconsin.

It happens that in western Wisconsin much larger deposits of this limonitic ore have been found than in Minnesota. It has been considerably worked. In the Wisconsin geological reports it has occupied an important place in the discussion of the ores of that state. It appears to be found there in extensive masses lying on the slopes that descend from the bluffs, sometimes capped by the Lower Magnesian limestone, to the adjoining valleys, and is described as belonging to the underlying sandstone.* In other cases, as learned more lately, it lies on the flat tops of the bluffs, directly upon the Lower Magnesian. In the latter position it has been exploited and considerably used to mix with the lake Super- ior hematites at the furnace at Black Biver Falls, Wisconsin. It is noticeably abuudant at Hersey or Woodville, and extends to Knapp, a distance of 8 or 10 miles. It has from forty to fifty per cent of metallic iron, fifteen to twenty of silica, and generally over one tenth of one per cent of phosphorus, and fluxes easily.

In Minnesota this ore is not of great value, so far as known, nor indeed is it in Wisconsin, in comparison with the ores of the crys. talline rocks. Its chief interest consists in its relation to the Creta- ceous. It is found making a layer separating the Cretaceous from the underlying formation, whether the lower rock be Lower Magne- sian limestone, St. Croix sandstone, or the Galena limestone. Its age is therefore not determined by the underlying stratigraphy, but by the overlying, and as already stated, it indicates a former great development of the Cretaceous further east than the state of Minnesota.f

This ore in Minnesota seems to have existed at first largely or entirely in the form of a sulphide, and to have been changed by slow degrees to oxide. Such is the fact also in Wisconsin -accurd-

♦Geology of Wisconsin, vol, iv, (1882,) pp. 54—56; 378.

tAttention was called In the first annual report of the Minnesota survey (p. 110), to lignites and green and blue shales in the Grand Traverse region, state of Michigan, that aro probably of Cretaceous age.

Iron Ores Of Minnesota. 153

ing to the descriptions of professors Strong and Chamberlin. This is exactly in keeping with a peculiarity of the Cretaceous clays that appertain to the Fort Benton group. Crystals of pyrite are fre- quently disseminated through them. The debris of the disrupted Cretaceous is so plentiful sometimes in the drift clays in Minnesota, carrying with it this sulphide, that not only are its crystals pre- served, but in some cases by their solution, forming sulphuric acid, a union is effected with the lime of the " Winnipeg limestone" peb- bles, causing the growth of nests and plates of perfect selenite, or sulphate of lime, the magnesia of the same pebbles uniting to form the predominant characteristic of the well-known alkali of the plains, or Epsom salt. Pyrite and selenite crystals in plates and in nests are a frequent and attractive object in excavating in the' drift clays in the western part of Minnesota. This original depo- sition of sulphide of iron has, when studied in connection with the occurrence of other metallic sulphides in the Silurian rocks, as blende and galena, a significance to which we cannot refrain from calling attention.

It is well known that in tbe " lead region" of southwestern Wis- consin, and in northeastern Iowa, and northwestern Illinois, the sul- phide of lead, which has formerly attracted much attention as an ore of economic importance, is accompanied abundantly by pyrite and more sparsely by blende and chalcopyrite. It is plain that if the Cretaceous ocean prevailed across the Mississippi valley in the latitude of Minnesota, it must have covered it entirely further south, and hence must have covered the Silurian limestones where these sulphides exist. It has been argued by Prof. Chamberlin, that these sulphides were precipitated chemically in the Silurian ocean by the ascent of the gaseous products of organic decay from ' the shales of the underlying formation, i. e. from the strongly fossil if erous Hudson River rocks. The troublesome fact that these sulphide deposits occupy crevices and " gashes" that were formed, evidently, since the deposition and consolidation of the Silurian beds, can hardly be explained on that hypothesis. There seems to be more reason to suppose that they were precipita- ted from the Cretaceous ocean and were gathered into these crevices during Cretaceous time, after the Silurian limestones had been ex- posed long to atmospheric agents and eroded by numerous gorges, and bo weathered that they were rendered porous and cavernous. This explanation of their origin is in keeping with the general ac- tion of the Cretaceous ocean in the deposition of abundant sul- phide of iron in Minnesota. What may have been the precipitat- ing agent, whether ascending sulphureted hydrogen, due to organic

154 Bulletin No. Vi.

decay, or some physical conditions that affected the chemical solu- tions in the Cretaceous ocean, we will not here inquire.

(5.) Geographic Distribution Of The Crystal-

Line Iron Ores Of Minnesota.

The geological map which accompanies this bulletin will convey at a glance an idea of the areal distribution of the ore-bearing formations. With the exception of the Laurentian and the later strata of the Keweenawan, ail the formations here represented are iron-bearing to a noteworthy degree.

Beginning with the lowest, the Vermilion rocks (the crystalline schists) enter the state from the northeast, to the west of Hunter's island. They hold magnetic ore north of Long lake, and north of White Iron lake. There is great probability that they will be found to contain other deposits of ore of the same kind. The formation widens out along the international boundary westward, but has a geoeral strike toward the southwest. It is evidently the Vermilion that crosses the Minnesota river at Morton and Red- wood Falls, although the exact manner and area of its distribu- tion before reaching there from the northern limit of the state are largely conjectural owing to the abundant drift sheet. It is divided into two belts, that on the international boundary running soutbwe8tward from Basswood lake being the principal belt. The smaller belt is further south, and skirts along the northern edge of the granite of the Giant's range, and is possibly the same that appears on the Mississippi river at Pike Rapids in Morrison county.

The Keewatin ore follows the Keewatin formation. This comes into Minnesota from the northeast immediately to the south of the Vermilion belt and occupies the area between the two Ver- milion belts. It strikes southwestward to Ely, and Tower, where the works of the Minnesota Iron company are situated about in the center of the belt. It thence soon passes under the drift and is difficult to follow. It can only be said it acquires a more westerly course as it extends southwest. It has been identi- fied on the upper waters of the Prairie river, and of the Little Fork and Bowstring rivers north of Winnibigoshish lake. It is not found so as to be distinguishable at any points in the valleys

Iron Ores Of Minnesota. 155

of the Mississippi and Minnesota rivers, bnt the deep well at Moarhead* in the valley of the Bed river of the North, encount- ered a peculiar greenish, gneissic rock, immediately below the drift, which is similar to some portions of the Keewatin, and this may be taken as the only indication that has been discovered, of the direction of strike of that terrane.

The Taoonio ores will be found accompanying the Animike slates and quartzytes. The titanic magnetites which occur in the gabbro are of the same age. There are three phases that here should be considered. (1.) The lower, non-iitanic magnetites, which are associated with the Pewabic quartzyte, and which do not have any recognizable or important distinction from the siliceous magnetites that occur at a higher horizon, mainly preceded the outflow of the gabbro, and they are found along the southern edge of the granite range of the Giant's hills, limiting, on the north, the strike of the Animike (if the Pewabic quartzyte may be in- cluded properly in the Animike) in its course from Gunflint lake to Pokegama falls. This quartzyte is apparently the same as that at New Ulm, and in Cottonwood county,f in the southwestern part of the state, and appears again at Pipestone, in Pipestone county. But the most westerly point at which it promises iron ore is near Pokegama falls on the upper Mississippi. The strike from there is southwesterly, and it probably prevails largely iu the region south from Winnibigoshish lake. Whether it is separated into two areas, or not, is unknown. In all places where this quartzyte is known in the state it has a prevailing southeasterly dip, indicating that it extends in an unbroken sheet underneath all that part of the state lying to the southeast from its general line of strike. (2) The titanic ores of the gabbro group, which next succeed, have a rather wide dispersion in the northeastern part of the state, north of lake Superior. There are places where the gabbro outflow in- volved, and still embraces, considerable amounts of the older quartzyte with its characteristic non-titanic magnetic ore, but in general the titanic ore of the gabbro is unique, and characteristic of the gabbro rocks. In general these rocks strike from Pigeon point and Gunflint lake, southwest to Duluth and nearly to Thom- son, on the St Louis river, which is the most westerly point at

Bulletin No. 5. pp. 27— 3D.

tThis quartzyte, with ItH parallels, has Leon supposed to represent the Potstlani sand- Stone, of Potadam. N. Y., but there In another series of red sandstones at the. top of the Animlko, forming the basal beds of the Keweenawan. which may he the true Potsdam. It is evident that a re-exam inut Ion should be made of Hie Potsdam region, in order to ascertain whether the typical Potsdam is the equivalent t.f the "(iruimlar quartz" or of the "Red Kandrork."

156 Bulletin No. Vi.

which they have been identified. In some way they swing round the western end of lake Superior,* and appear again in northwest- ern Wisconsin, but they ha?e not been reported to embrace note- worthy quantities of iron ore, except in Minnesota. (3) The softer ores of the Taconic occupy a higher horizon, and they seem to be associated with great quantities of red shale, and in some cases this red shale has been disintegrated, and disseminated along with the associated red ore, over large areas, staining the drift clays and giving character to the soils. This is prevalent southward from the strike of the upper Animike rocks, and it blends with a similar coloration that is due to the disintegration of the Keweenawan sands and shales. These upper gray and black slates and quartz - ytes, constituting the Animike proper, are conspicuously developed from Pigeon point to Gunflint* and Gobbemichigamma lakes, but they are lost in their southwestward extension. It was supposed, at one time, that these strata were overwhelmed by the gabbro and hid from sight, but it is now believed, as already stated in this bulletin, that they succeeded the main gabbro sheet chronologic- ally, and should be found) if they ever existed as such, lying un- conformably upon it. On the other hand, there is found, in the region where they might be expected, a volume of eruptive rocks associated with various detrital rocks, more or less of volcanic origin, which have been denominated and mapped as a part of the Keweenawan. Further west, however, approximately in the line of strike of these rocks, and beyond the most westerly known ex- tent of the characteristic Keweenawan rocks, northwestward from Duluth, these upper Animike strata appear to be represented, and to be highly ferruginous with red shale, and with red hema- tite. This red shale and the associated red iron ore, with the banded jaspilyte, occupy, so far as can be seen, the stratigraphic position which is occupied further east by the gabbro sheet, and it is a reasonable inference to ascribe their existence to the effect of the eruption of the gabbro and the succeeding traps upon the Ta- conic ocean, causing, as has been detailed in discussing the origin of the Keewatin ores, such chemical precipitation of ferric oxide as to give all the sediments an irony coloration, and occasionally a chalcedonic composition. Still further southwest the Animike strata have not been identified with certainty. They seem to turn rather abruptly toward the south, and even toward the southeast They constitute, with the Pewabic quartzyte, the overlying, north- dipping formation at the unconformity at Penokee gap,f in north-

♦Gabbro was found in the Stillwater deep well. Bulletin No. 5. p. 27, foot note. . It is probable that the "trap" at Taylor's Falls is nearly of the age of the gabbro.

tThis has been described both as a "fault,'* and as an unconformity. It was visited and described by A. Winoholl in 1887, 16th Minnesota report.

Iron Ores Of Minnesota. 157

western Wisconsin, and there lie unconformably on the crystalline schists, or Vermilion series. In the county of Morrison, Minne- sota, these same north-dipping slates appear on the Mississippi river, at Little Falls, overlying unconformably a beries of gneissic rocks and mica schists from which they present a totally different lithology. They have been conjecturally identified with some of the drillings in deep wells still further southwest, but they afford no outcrops.

The foregoing is all that need be said respecting the geographic distribution of these ores in Minnesota. As ores they are perfectly distinct, lithologically and stratigraphically, and need not be con- founded by any geologist Their actual distribution, in conse- quence of the heavy covering of drift which characterizes much of the northwest, is less certainly known. Tae formations, however being identified at different, and often distant points, afford us a general skeleton of their shapes and dimensions. It is only to partially fill out this skeleton that has been attempted above.

Generalized Section.

In order that the reader may form a conception of the geologi- cal relations of the formations containing the iron ores of Minne- sota, a drawing is represented on plate xv showing the succession and dip of the strata from Vermilion lake southeastwardly to Penokee gap in Wisconsin. The elevations above tide are ex- pressed in feet at various points. This generalized section is sup- posed to follow, from Vermilion lake, the line of the Duluth and Iron Range railroad to Two Harbors. On the south side of lake Superior the section is based on the atlas and sections of the Wis- consin Geological survey, except as to the immediate vicinity of Penokee gap, which is drawn according to observations of the Minnesota survey, differing, however, in no essential from the Wisconsin survey.

(6). Comparisons With Michigan And Wisconsin.

The comparative annual production of the Minnesota mines and those of Wisconsin and Michigan has been stated in the first pages of this bulletin. It has also been shown, in the description of the distribution and equivalents of the Minnesota ores else- where, that the formations which carry the Minnesota ores, with

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the exception of the gabbro and the crystalline schists, are well rep- resented in Michigan and Wisconsin, bat that the two chief iron- bearing horizons of Minnesota are not well known and distinct for- mations in those states. In some of the publications of the Min- nesota survey attention has been called to this distinctness, even at Negaunee and Ishpeming, as well as in the Gogebic-Penokee range.* It is evident, if our conclusions are correct as to Minne- sota, that there is a necessity of making careful observations on the southern side of lake Superior, in all the iron districts, in order to determine which of the iron formations the separate mines may belong to, since it will be found not only that there is a dif- ference in the ore that the two formations produce, but that the relation of the ore to the enclosing rock is so different that it necessitates different plans and mining methods. It is our belief that much money has been wasted in diamond-drill work, as well as in underground tunneling, because of ignorance of the habit and form of these two formations, and of the normal position and relations of the ore to the country rock. All mining can done cheapest when the superintendents and the mining captains thoroughly understand the facts and conditions of the problems that they have to solve. As to Minnesota there is not the shadow of a doubt as to the actuality and different pos£ of these two for- mations. We believe that by a short review in the field the strati- graphic position of all of the Michigan and Wisconsin mines can be determined and that it will be found that much of the con- fusion and hesitation that have been manifest, not only among geologists, but also among mine-operators, have been owing to the confounding of two distinct formations under one term, ("Huron- ian"). The anomalous existence of the "Animike" strata only on one side of the great synclinal valley, would no longer stand as a reproachful stumbling-block to the systematic geologist, but the stratigraphy of the great basin would be found to be a harmonious unit.

We desire at this place only to call attention concisely to some of the comparative relations of the iron ores in Minnesota with those of Michigan and Wisconsin.

It has been the practice of geologists who have written of the iron ores of Michigan and Wisconsin, to place them all in one category, assigning them to the "Huronian," and there was a ten- dency at first to consider the Minnesota ores as belonging to the same undefined and uncertain position. The first expression of the Minnesota survey on this point was an initial dissent from this

Sixteenth and seventeenth annual reports.

Iron Ores Of Minnesota. 159

classification. It is to be seen in the thirteenth annual report, pages 24-37, where three iron horizons are mentioned as occurring in north-eastern Minnesota, that at Tower being described as in a lower horizon than either of the others. That was in the report for 1884. The Taconic (Animike) strata, are shown by a diagram on page 22 to overlie the formation containing the mines at Tower. The nature and the wide extent of this distinction have been grad- ually unfolded from that time to this. The only geologists who have recognized it, are those who have worked on the Minnesota survey. Certain differences of lithology, indicating some possible difference of age in two parts of the "Huronian" were noted by Bonney in the vicinity of Sudbury, but he had no reference to the iron ore horizons. Dr. A. C. Lawson, without calling in question the old tenet that the ores of iron in the lake Superior region are all in the "Huronian," noted positive data by which he was in- duced to separate the typical Huronian from the schists underly- ing. Dr. B. D. Irving, while noticing the stratigraphic separate- ness of the typical Huronian and the Animike from the underlying formation (which Dr. Lawson named Keewatin ) still insisted that all the iron ores belonged in the "Huronian." Prof. C. A. Van- Hise, so far as he has expressed any views, appears to be of the same opinion, and all the corps of the Canadian geologists, under the lead of Dr. Selwyn, still sweep all the "schists" into the Hu- ronian, and expressly exclude the Taconic strata, as represented in the Animike, from the Huronian formation, regarding them as "primordial," or "lower Cambrian," supposing that such a distinc- tion of names really necessitates a distinction between the things named.

Suffice it at this place to say that we have made comparative studies both in the area of the original Huronian, in the Marquette and the Gogebic ranges, and at Black Biver Falls, and have availed ourselves of re-examinations at Penokee Gap in Wisconsin,* suf- ficient to confirm our interpretations, and that we can make the following comparative statements with confidence:

In Michigan both of the principal iron-bearing formations are exploited, viz : that which we know as Keewatin, and that which we know as Taconic. Specifically we think the Jackson mine at Negaunee is in the Keewatin, and that the new mines about a mile and a half east from Negaunee and all of the Gogebic mines are in the Taconic. No ore is yet known in Michigan that can be parallelized with that in our Vermilion series. Nor is any titanic magnetite yet known in Michigan.

That of A. Wlnohell. Sec the sixteenth annual report, p. 101.

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In Wisconsin the ores of the Penokee range are in the Taeonic, and are believed to be of that phase of the Taeonic ores which we have designated carbonated iron group. There are magnetic belts in Wisconsin, lying to the south from the Gogebic range, as yet un- exploited, and comparatively unknown, whose geographic position is such as to indicate that they are in the Vermilion crystalline schists. In the Penokee range there is no doubt but the same gradual change takes place as we have noted in Minnesota, viz : a change from hematite to magnetite in passing from one end of the range to the other. The western end of the Penokee range seems to hold magnetic ore prevailingly, while in Minnesota this seems to be true of the eastern end of the Mesabi range. As to the Menominee region, we are not familiar with it, but it would appear from the published descriptions that most of the mines are in the Taeonic. At Black River Falls, the characteristic features of the Taeonic magnetites, pertaining to the Pewabic quartzyte, are plainly seen. Much of the iron-bearing rock here, however, lies apparently in the horizon of the impure jaspilitic hematite horizon of Minnesota. Nothing is known in Wisconsin of any titanic iron ore.

It will be seen by this, and by the accompanying geological map, that Minnesota possesses not only a greater variety of iron ores, thus far known, than either of the great iron-producing States on the south side of the great lake, but also a greater territory in which iron ores may be expected to be found in merchantable quantity and quality. In the body of this report it was intimated that the Mesabi range is the northern rim and parallel of the Penokee- Gogebic range on the south side of the lake, and that it might in the future exhibit a great development comparable with that of the south side of the lake. Even before this report closes comes the first verification of this prediction. There can be no reasonable doubt that in Minnesota, about the western and north- western confines of the lake Superior basin and extending west- ward to the Mississippi river, there will yet be mined in the Mesa- bi range even greater quantities of hematite than have been taken from that marvel of mining districts, the Penokee-Gogebic range, which blazed out with such a brilliant record only a few years ago.

At the same time, the ores of the Vermilion range, belonging in the Keewatin formation, while they can be traced distinctly north- eastwardly to and beyond the Canadian boundary, a distance of over fifty miles, are also known to extend, with the strike of the Keewatin formation, south west wardly and then westwardly, across the upper waters of the Prairie river and to the headwaters of the

Iron Ores Of Minne80Ta. 161

Bowstring or Big Fork river. There is no known reason to ex- empt this belt of rooks throughout its extent from the sanguine expectations that have been put upon it in the region of Tower and Ely. It can be traced about one hundred miles, and it may supply iron ore on every mile for that distance.

(7). Synoptical Review And Outlook For

The Future.

In the foregoing discussion of the geology and distribution of the iron ores of the state we have presented the subject as it ap- pears to us in the light of our recent investigations. As some of the results which we have reached are different from those of our predecessors it may be well, in the interest of those who do not have the time nor disposition to examine the report exhaustively, to re- peat more concisely some of the principal ideas we have endeavored to teach and illustrate, and the conclusions to which we have ar- rived.

1. The magnetites of the Vermilion schists are of the age of the "crystalline schists," in the upper part of the Laurentian. They are variable as to their content of titanium and have their parallels in the magnetites of the Laurentian gneisses of the east- ern part of the United States and in Canada.*

They are derived largely by hydro-thermal fusion and meta- morphism from hematites like those of the Keewatin at Tower — the enclosing rocks in the same way having been produced from green schists and gray wackes like those of the Keewatin. Being at a lower horizon they experienced this change while the overly- ing strata were exempted. There is always a conformable transi- tion from the Vermilion into the Keewatin. When they show titanium they must be referred to an early eruptive origin and have their genetic representative in the titanic magnetites of the Taconic.

2. The Keewatin hematites and jaspilytes were derived from chemical precipitation in Keewatin time from the Keewatin ocean which, while essentially an ocean of hot alkalinic water, was dis- turbed continually by volcanic action and by the acid rains that volcanoes produce. The Keewatin rocks are almost entirely at-

In the foregoing pages no analyBls of magnotite from the crystalline schists is given bowing any titanium. A more recent careful analysis of apamplc of this ore how- ever gave about ten per cent of titanium.

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tributable to volcanic agencies, as to the origin of their materials, but to sedimentary agencies as to their structure. The chemical origin of the jaspilyte as an oceanic precipitate is inseparably connected with and proves a like origin of the hematite. These hematites, being convertible by hydro-thermal agency into mag- netites, and the Keewatin rocks by the same cause to schists and gneisses, are almost unknown in the Atlantic border region, where it is to be presumed this metamorphism was greater than in the interior of the continent,and their place is hence supplied by the "Laurentian" gneisses.

There are two sets of associated minerals in the Keewatin hema- tites. One is original and was formed cotemporaneously with the ores, and one is secondary, and was introduced at a later period of upheaval and fracture, the latter probably being that of the great Cupriferous (primordial) age. The metamorphism of these rocks took place in Archaean time. We see no evidence of any deep- seated mineralogical changes later than the eruptive epoch of the primordial.

3. The Taconic formation embraces a variety of ores — non- titanic magnetites at the bottom, jaspilitic hematites next above, soft hematites and titanic magnetites. These are found to con- stitute a well marked belt extending from Pigeon river westward to the Mississippi river, although the titanic magnetites seem to diverge from this course and to run below the St Louis river a few miles west from Duluth. Except the titanic magnetite of the gabbro, which is a primary constituent of the rock, and is of erup- tive origin, all the ores of the Taconic seem to be of chemical origin, and all, except those referable to concentration from oxidized carbonates, to chemical precipitation in the Taconic ocean under circumstances identical with those of the precipitation of the Keewatin hematites.

4. As to the limonites which we refer to the age of the Cretaceous, and which are more important in Wisconsin than in Minnesota, we find them overlying formations of different ages, from the Galena to the St Croix sandstones, and hence we believe their origination did not depend on any of the older formations, but on the char- acter of the ocean which once covered a large part of the north- west. We would also suggest that, while they seem to be largely the result of change from sulphide of iron in situ, their existence may be due to sudden changes in the alkaline waters of the Cre- taceous ocean brought about by submarine volcanic eruption in a manner analogous to those of Keewatin time, to which we have ap- pealed for the origination of the early hematites.

Iron Ores Of Minnesota. 163

As to the future of the iron ore industry in Minnesota, the pros- pect is very flattering. With the possession of a greater variety and a greater areal distribution of iron ore than any other north- western state, there may be expected, other things being equal, a correspondingly greater development So far as we know, other things, which depend on natural conditions, are nearly equal. At the present time roads and railroads are lacking. There can be no doubt, however, that these will be supplied. The slightly greater distance from the great centers of fuel in Pennsylvania and Ohio is the only unfavorable consideration. For many years, however, charcoal can be substituted for rock coal, drawing the supply of wood from the forests with which northern Minnesota is abundantly supplied. This is the next great step that the industry should take on in Minnesota. It would obviate freightage in both directions, and the existence of pig iron, the product of charcoal fur- naces in the upper Mississippi valley, in sufficient quantity, would invite and create the establishment of numerous manufactures which depend on a supply of Bessemer iron. At the present time the revenue that is derivable from the iron ores of Minnesota, except that which comes from their first production, is reaped by the manufacturers who buy them and convert them into pig iron, or into the manifold articles of civilization into which iron enters. Large quantities of the Bessemer ores of the state ought to be converted into useful articles within our own borders, but as yet we have not a single furnace for reducing them, and all the pig iron or other iron that is employed in the manufacture of iron articles is purchased from eastern furnaces.

In addition to the advantages that warrant confident expecta- tions for the future, based on natural conditions, as enumerated above, it may be further stated that the methods of concentration of lean ores such as have lately been put into practice for low-grade magnetites in the eastern states, are applicable on a large scale in Minnesota. If there be anything noticeable above all else connected with the manner of occurrence of the basal magnetites of the Taconic, it is the abundance of low-grade and medium-grade magnetites. The magnetism is intense in these ores, and can be followed for many miles, although when carefully examined the precentage of iron is found often to be too low to warrant mining by the ordinary means. Such ores have been concentrated for several years at the Chateaugay mines at Lyon mountain, New York, in the Adirondack mountains about thirty miles west of Plattsburgh, by a method of crushing and jigging and screening, which is applicable to both hematite and magnetite ores, the object

161 Bulletin No. Vi.

being to separate by gravity the iron ore, which is heavy, from the lighter particles composing its gangue; 122,814 tons (long) were thus concentrated between Sept 26, 1886 and Jan. 1, 1888, at a cost, for crushing and concentration of 34.36 cents per long ton.* This included fuel, labor, oil waste, etc., mill supplies, renewals and repairs. This process also removes some of the phosphorus 9 raising the grade of the ore. This method is profitably em-, ployed in connection with mines that also produce merchantable magnetite, in which the cost of mining the low-grade ore is can- celled by the ordinary operation of the mine.

The Edison magnetic separator, recently invented, has been suc- cessfully applied to the concentration of lean magnetites from Port Henry, Chateaugay, the Croton mines in Putnam county, N. T., and others from Pennsylvania and New Jersey. This method is dependent on the magnetic quality of the ore, and consists in letting the crushed ore and gangue fall within the field of attrac- tion of a powerful magnet which withdraws the ore from a per- pendicular descent causing it to fall into a hopper or other apart- ment separate from that into which the non-magnetic material falls. The magnet is increased or diminished in power by regu- lating the wire coils which surround it. A dynamo furnishes a current of 25 or 30 amperes and 110 volts. t By this means the proportionate amount of phosphorus in the ore is reduced, that element being in the form of crystals of apatite and non-attract- able, and in some cases the titanium is affected in the same man- ner. There are several other methods that take advantage of the natural magnetism in the ore, and some are in use at several of the mines in Sweden and others at the Croton mines in New York.

♦Jour. U. S. Assoc. Charcoal Iron workers, vol. vlli., p. 10.

tMethods of concentration, and the machinery required have been described re- cently by John Blrkinbine In the Jour. U. S. Assoc. Charcoal Iron workers (1889).

Part Ii.

METHODS OF EXPLORATION AND MINING, AND DESCRIPTIONS OF THE VARIOUS MINES.

An account of the mining interests of the state, since their begin- ning, would not be complete without a description of the early methods of searching for ore bodies and of travel in the wild regions of the northern part of the state. Owing to the construction of railroads which will penetrate the most remote and unsettled por- tions of the mining districts, and, on account of the building of wagon roads in the frontier counties, these early customs will soon beoome entirely obsolete, and will be matters of history and of value as such. No other mining region in the United States has ever been explored and developed in precisely the same way as the iron ore districts of Minnesota. And no other region will ever be so developed, for the necessary conditions of remoteness from rail- roads, abundance of canoeable water in the shape of lakes and rivers, and frequent exposures of the underlying rocks with their store of iron, are to be found in no other part of the country. The folding of the earth's crust brought the ancient rocks up edgewise to the surface, and the subsequent action of the moving ice sheets of the glacial epoch scraped off the decayed debris, smoothed down the rough peaks, and left polished domes of fresh rock in their places, eroded valleys in which gathered the waters when the ice melted away and formed the countless lakes of the region, without which the explorer would be almost unable to traverse the country, bat borne on the surface of which he can travel farther in a day than he could on foot or horseback.

Early Methods Of Exploration.

A person who to-day steps into an elegant coach on the Duluth and Iron Range railroad, complete in all its appointments, and in a few hours is safely transported along the shores of the "Big Sea Water1' to Agate bay and then for the first time up over the

166 Bulletin No. Vi.

great Mesabi and Giant's ranges to the far-famed iron mines of Vermilion lake which are now among the wonders of the world, can have but a faint conception of the long days of labor which it required less than six years ago to make the same trip.

Before the construction of the railroad there were two ways to penetrate this wilderness and get to that inland lake, the home alike of the red man and the red iron ore; either by walking from Duluth over the old Vermilion lake "trail" which led through swamps and forests, over mountains and through gorges, or by a long and roundabout canoe-route down the north shore of lake Superior to Pigeon point or Grand Portage and then back along the course of the boundary waters. In any case an explorer who started into this wilderness was obliged to make up his mind to carry his entire outfit for many weary miles on his back, and had to prepare to meet annoyances and obstructions innumerable, from the sun which warmeth by day to the mosquito which swarmeth by night, from the storms of the lake and the wetting and ruination of all his supplies, to the cutting of trees which had fallen across his portage trail. It mattered not whether the trav- eler were a native Indian, an explorer for iron, a settlor who wished to take up a claim and make his home there, a state geologist, or a man with the wealth of Croesus; all alike must carry their loads and tramp through the interminable swamps infested with insect pests and almost boiling under the heat of the sun. If it were winter the trip was made on snow-shoes, with dog trains to haul the toboggan loaded with the supplies and camping outfit. Here again the lakes afforded the easiest roads, and the winter trails led directly across the largest bodies of water. Plates xvi and xvii will give an idea of the earlier substitutes for railroad trains and steamboats, used since time pre-historic in Minnesota.

Both the dog- train and the canoe are of Indian origin and manu- facture. It is one of the examples of the wise economy of nature that in the region where lakes and water courses are abundant, and traveling by canoe the only expedient way in the summer season, the white birch which is so well fitted for making canoes and domestic utensils should be abundant and grow of great size; while in the southern part of the state where the land is drier and more open and penetrable there are but few small birches found.

These birch canoes are the best thing that could be devised for use in this region, where the canoe first carries the traveler for a distance and the traveler then carries the canoe. They vary in length from ten to twenty-five feet, and are called one-, two- or three-man canoes, according a9 they will hold one or more men

Iron Ores Of Minnesota. 167

with their necessary supplies for two or three weeks. They are quite light when dry, weighing from forty to seventy-five pounds, or more. A canoe of average size is easily carried inverted on a man's head and shoulders, as represented in plate xvm, and if the traveler is in a hurry he will take a "pack" of fifty pounds besides.

To make a birch canoe an Indian first selects a good -sized birch tree, devoid of limbs for fifteen or twenty feet above the ground. With an axe he then makes a vertical incision up one side of the tree as high as the bark is good, or as far as he desires to cut it off. The bark of a birch tree is generally about a quarter of an inch thick and is under high tension owing to the annual growth of the wood inside. In the spring the bark when cut will shrink away from the incision aud will frequently peel off of its own accord for two or three inches on each side of the cut. The Indian strips off this bark in one whole piece with his axe, rolls it up and takes it home. The inside is then scraped and the outside peeled off to make it smooth and obtain the desired thickness. This large piece is for the bottom of the canoe and reaches from end to end, the in- side of the bark forming the outside of the canoe. A frame-work is made of white cedar, and around this framework the bark is fitted. The ends are made pointed and the sides are enlarged by sewing pieces of bark on them. The sewing is done with an awl and the thread used is obtained from the inside of long, flexible spruce roots. The canoe is allowed to dry a short time and is lined first with thin cedar withes running lengthwise of the canoe and is then braced by transverse bows of cedar on the inside. The seams are covered neatly with pitch, aud a couple of cedar paddles com- plete the outfit. Such a canoe will hold from three hundred to fifteen hundred pounds, will last two seasons, three with care, and in the hands of a skilful canoeman will navigate the roughest waters of lake or rapids in safety. It takes an Indian and his family three or four days to make one and they are worth from five to twenty dollars, according to the demand, the season of the year, the size and beauty of the canoe and the place of purchase, as well as the necessity or greed of the Indian owner.

Great care is sometimes taken by the Indians to have a fine dog train. Three or four dogs are secured and trained so that they will travel long distances and haul a heavy load over the snow- oovered lakes. The following description of one is taken from the Vermilion Iron Journal of April 3, 1890:

"There arrived in this city, (Tower), late Thursday afternoon, one of the most magnificent and well-trained dog -teams it has been our fortune to see in this or any other country. There were four

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of the dogs, three nearly white, the other almost black; and they were the brightest, liveliest quartette of canines that have ever yet come in from a woodman's home. The equipment, too, was far from the ordinary style. The dogs each wore a nice, ornamental collar, supplied with tiny Russian bells that tinkled merrily to their lively little trot when on the road. In addition to this, each was comfortably covered with a handsome blanket worked in fancy colors and ornamented with Indian beads. The toboggan was an exact counterpart of those used by the Esquimaux, being a frame covered by a tanned moose skin, the whole thing very much resem- bling a whitewashed coffin, except, perhaps, the fancy striped painting on the sides. The toboggan was water- tight and could be used for a canoe in case of an emergency. The outfic was the prop- erty of a half-breed, Richard Lyons, who brought in a man named Frank Mosher, from Fort Francis, Canada, 110 miles from Tower. The entire distance was made in twenty-two hours' travel, taking one night's rest when about midway in their journey."

8uch traveling as that will grow more rare from now on, because Indians appreciate the use of a railroad train as well as anybody.

Besides a canoe in the summer months and snow-shoes in the winter, of course an explorer requires to be otherwise equipped for the business of searching for iron mines. He must be endowed both by nature and by training with qualities of patience, endur- ance and observation. He must be able to travel through any kind of a wilderness and not lose his way. He must be a canoeman, a packer, a cook and a geologist. He must know iron ore from trap rock, and must have a general idea of the geology of the region, so that he will not waste his time and energy and lose valuable oppor- tunities of discovering and acquiring desirable mining properties.

Incompetent men are very often relied on to do work for which they are in no wise fitted. Several cases have been known to the writers, where wealthy capitalists and even intelligent men who are engaged in the iron industry in Ohio and Pennsylvania, have sent parties to spend the summer in searching for iron ore, which parties were in the charge of men who insisted on exploring dur- ing the whole season in a district of gneiss and crystalline schist, whereas a person acquainted in the least with the general geology of the iron ores of this state would have informed them that such search would be fruitless. The result was that they spent large sums of money and had nothing to show for it.

Outfit. It is seldom that an explorer goes alone to look for iron or timber land. The operations of camping and traveling can be much better conducted by a small party of two or three. Their

Iron Ores Of Minne80Ta. 169

outfit should not be made any bulkier than necessary, and yet it is better to have too much than too little, for a person suffers greater inconvenience from the lack of sufficient food or clothing or blank, ets than from the extra exertion required to transport them.

A list of the various articles proven by experience to be of use and almost of necessity for an explorer, would include the follow- ing: For personal equipment he should have a couple of large, heavy woolen blankets, weighing eight pounds each; a canvass or rubber blanket to lay under them; a sack about the size of a seam- less wheat sack, to hold his clothing; this may be made of heavy oil-cloth or of a rubber blanket, if he desires to have a change of dry clothes; a small " A tent" made of 6-ounce or 8-ounce duck. Of course this should be large enough to contain all the members of the party, and should be thick enough to keep out the rain of heavy showers in the spring. In the fall a "shed tent" is conven- ient, for a fire can be built in front of it for warmth, and rains are not so frequent. Sometimes a party does not need a tent for three or four weeks at a time, but can sleep under the blue canopy of the heavens with perfect comfort. In his clothes-bag the explorer puts all of his personal accoutrements and toilet articles. These should comprise extra suits of flannel underwear, flannel socks, shoes or shoe-pacs, sewing bag, flannel shirts, etc. He should have for constant daily use a suit of strong clothes through which air can circulate freely; and his foot-wear should be carefully selected. Whatever he wears on his feet should be large enough to be worn above at least two pairs of woolen socks, and it is better to wear shoes or shoe-pacs, with or without canvass leggings, than long, heavy, water-tight boots or boot-pacs. A person will be in the water several times a day, and frequently for a large part of the day, and it is easier to tramp around with a shoe full of water than a boot full; and besides, it is easier to remove a shoe and pour out the water, than to pull off water- soaked boots. A small case of com- mon toilet articles is convenient, and two or three simple remedies for biliousness, colds and dysentery, almost a necessity. Almost anything in the way of a hat can be worn, generally, however, something which will not interfere with the operation of a " pack strap," or be knocked off easily by bushes.

In the spring of the year the explorer is apt to be greatly troubled by the insect pests, "deer flies," ''black flies" and "wand flies" or "midges," ("uo-see-unis") by day, and mosquitoes at all times. It is sometimes necessary to build a small "smudge" when- ever a person stops to rest or make observations, and at times im- possible to write notes without gloves on one's hands and a hand-

170 Bulletin No. Vi.

Lerchief over one's neck and face or an Indian to stand by and wave a brush of branches and leaves over one's head. Bat such days are not very frequent and do not occur after the middle of July. Various kinds of ointments are recommended to keep off the mosquitoes, but they are generally worse than useless. A person soon becomes inured to them and his system is so inoculated with the poison that their bite ceases to produce swellings. The best way is to have the tent fringed at the bottom and up both sides of the door with half a width of "cheese cloth." This can be drawn in around the bottom and held down by hammers, specimens, blankets, etc., while the door-flap can be pinned together by clasp clothes-pins. The few mosquitoes that are in the tent can be Hilenced by singeing their wings in the flames of a candle, and the tired explorer can obtain the sleep that is an absolute necessity, unmindful of the hum outside which sometimes sounds like a pipe- organ at a distance.

The camping outfit should include a set of pails, pressed tin dip- pers which fit together, frying pans with hollow handles, plates, knives, forks, spoons, and a tin baker which can be set up before the fire, and can be folded into small compass for transportation. There should be an axe or two, a medium sized geological hammer for each member of the party and a miner's pick. The most con- venient method of carrying these articles, as well as the stock of supplies, is in "pack-sacks" which are made of canvass fitted with broad leather straps to go over a man's head and shoulders. With one of these contrivances a man can carry on his back a load of one hundred pounds across a portage of half a mile without resting, and when it comes to steady packing can go twice as far at ode "pull."

Each member of the party, unless he be an Indian, should be supplied with a good compass with which, by the aid of plats and maps, be can find his way in any part of the region. A dip needle is frequently indispensable in regions of magnetic ore. A small shot-gun and a couple of strong trolling hooks and lines will be the means of contributing a refreshing variety to the bill of fare and lighten both the load to be carried and the bill for groceries. In the matter of provisions individual tastes may to a large extent determine what shall be taken. All things like sugar, salt, flour, etc., that would be spoiled by being wet, should be carried in bags made of oil-cloth or oiled canvass. The staple articles of food which can be taken on a trip of this sort include flour, beans, ham, salt-pork, oat-meal, rice, tea, coffee, sugar, salt, pepper, dried ap- ples and prunelles or prunes, baking powder, pickles and dried

Ikon Ores Of Minnesota. 171

corn. Batter and apple-butter can be obtained and carried in wooden caddies, but canned goods are not suitable on account of their bulk and the angularity which prevents them from fitting well into the hollow of a person's back when in a pack to be trans- ported from one lake to another. Onions are excellent preservers of health and with fresh apples should be on hand as continually as practicable. In the proper season grouse, ducks, rabbits and other larger game may frequently be shot, and the lakes are gene- rally full of fish which will bite a troller. Blue-berries, red rasp- berries and strawberries are abundant and grow to remarkable size, so that a person can pick a pail-full in a short time. On the whole the bill of fare is excellent and even an Indian will get up an inviting repast in a few minutes.

On the ground. Around the shores of the numerous lakes the rook exposures are so frequent that a person can trace the outlines of the various geological formations with a fair degree of accuracy by following the shores alone. But the enterprising explorer roes everywhere; he climbs the highest hills and crosses the widest, densest swamps, for there may be an outcrop of iron ore in either place. He knocks off a corner here and digs off the moss there until he knows every foot of the ground around him. If he sees angular pieces of "float-ore" he attempts to trace them to their home and see if there is more like them. The observing pros- pector notices that the "float" has all come toward the south or southwest and he follows therefore toward the north or northeast, according as the glacial string on polished surfaces indicate that the movement of the ice-sheet was in one or the other of these directions.

A fragment of red jasper is considered as good an indication of the presence of iron ore in the vicinity as a piece of ore itself; but black jasper is regarded as a j>oor indication, and more than one property has been neglected because it contained or showed only black jasper associated with the ore.

If the ore is magnetic, as much of it is, the clip compass traces its boundaries and strike, and the claim is taken so as to include as much of the area where the needle stands at 90 as is possible.

Of course a prospector cannot tell very much off-hand about the exact quality of the ore which he discovers. He may be experienced enough to judge from the specific gravity as he weighs it in his hand that it contains 50 per cent, or (50 per cent, of iron; but of the presence of phosphorus or titanium or even sulphur, he can tell very little without an assay or analysis.

Diamond drill It is seldom that the extent of an ore deposit

172 Bulletin No. Vi.

can be learned without stripping or shafting or drilling. By far the most satisfactory way to ascertain the real value and extent of an ore deposit or the exact size and locus of the ore lenses is by the diamond drill. It is rather costly at first, but is the cheapest in the end. The core which it brings up is a faithful record of the rock through which it penetrates, and with such a record there need be very little speculation or doubt about the propriety of sinking shafts and attempting to find ore. By means of it the mines which are already in full operation are continually discover- ing new ore lenses at various depths below the surface. These drills can be worked at any angle and to almost any required depth, and will produce a core from one to three inches in diame- ter. According to a letter from Mr. H. A. Wilcox, dated June 16, 1890, a diamond drill hole at Soudan was made 1,319 feet in length- It ran at an angle of 24 degrees and was drilled near the center of the "Stone" location up to about under the point where T, BB and Z holes were started, and passed through "soap rock", jaspilyte, quartz, and white siliceous limestone.

The principle of the diamond drill is, , the rapid rotation of a hollow "bit" of which the cutting edges are the diamonds, set in such a manner that they are the only part of the tool that comes in contact with the rock ; and, second, a stream of water forced down through the interior of this bit, passing up outside of it and carrying away the material ground up by the diamonds.

The hollow bit is a steel thimble, having three rows of diamonds (bort or carbon) embedded therein, so that the edges of those in one row project from its face while the* edges of those in the other two rows project from the outer and inner periphery respectively. The diamonds of the first mentioned row cut the path of the drill in its forward progress, while those upon the outer and inner periphery of the tool enlarge the cavity around the bit, and admit the full ingress and egress of the water. The bit is screwed to the core- barrel or spiral grooved guide, and this to the drill rods which are made of heavy lap-weld tubing, and added section after sec- tion as the hole deepens.

When the drill -rods, with bit attached, are rotated and fed for- ward, the bit passes into the rock, cutting an annular channel. That portion of the stone encircled by this channel is, of course, undisturbed, and the core-barrel, passing down over this, keeps it intact until the rods are withdrawn, when the solid cylinder thus formed is brought up with them, the "core-lifter" breaking it at the bottom of the hole and securely wedging it in the core-barrel.

At the upper end of the drill rods is a water swivel, connected

MtRICAN DIAMOtJD ROCK-BORING COMPANY. (P. 173.)

IRON ORES OF XIXSEtMJTA. 173

with the Bteam pump. By mesne of this pump a constant stream of water is forced down through the hollow drill "rod, thereby keeping the bit cool and the hole clear of sediment, which is- forced by the water pressure up the outside of the rods to the surface. When a core is not required, a perforated or solid bit may be used, the detritus being washed out by the water, as when boring with the annular bit.

These general principles of boring with the diamond drill are always the same, the different machines, by slight changes, being applicable to any kind of rock drilling.

The diamonds are set by drawing the soft Bteel of the bit up around them, and each diamond projects exactly 8'j of an inch, bo sb to make the hole perfectly round and of the same size all the way. These diamonds wear off and thus sharpen themselves, and . to be reset quite frequently, sometimes every ten inches of boring, but the average is about six feet, taking hard jasper and soft schist together. One man can set three bits in a day and a bit set with diamonds is worth about $200.00. Corundum has been tried in the place of diamonds, but it has no effect on the jasper.

The core-bar is the tube just above the bit into which the core of rock projects and in which it remains while the drill is pulled oat. The longest core-bars are about ten feet, but the drill is pulled out every two'or three feet to Bee that it is working properly. Cuts of the shafting drill manufactured by the Amer- I ican Diamond Rock Boring Co., and of the core-bit, I core-lifter, core-barrel and perforated bit are shown I in plate six and figures 18-22. This drill is especially F adapted to long-bole boring in shafts, It will bore at any angle to a depth of 600 feet, and weighs when Bet up 1,000 pounds. The size of the bit is to 2 inches in diameter. In the annular or core bit, figure '" 18, the projections represent the diamonds, which constitute the cutting edges. This bit or boring head revolves at a speed of from 400 to 1,000 revolutions l per minute, the size of the core bored I out depending upon the inside diameter I of the bit, or more exactly speaking, on I the track cut by the diamonds which, it I will be observed, project so that they f alone come in contact with the material while drilling. q

rmSmCT' Figures 19 and 20 are the perforated Bit.

or solid bits which produce thn ordinary hole twecl for Masting

Bulletin No. Vi.

purposes, the rock being pulverized during the revo- lution of the bit. The water passes through perfora- tions made in the steel in sufficient volume to answer the same purposes which are provided for in the annular bit. The advantages of this method of boring are that the diamonds . will cut anything, the holes are perfectly t cylindrical and are carried in a perfectly I straight line in any desired direction.

Figure 21 is the core-lifter, a simple j mechanical contrivance for breaking and j lifting the cores which have been bored.

Figure 22 ie the core-barrel or spiral Fl0 s grooved guide and bit It consists of a Ufmb. wrought-iron tube, from eight to sixteen feet long, made the size of the hole to be bored and set with diamonds at intervals to prevent it from wearing. The spiral grooves are provided the full length of these tubes, to allow egress for the water and sediment on the way up to the top of the bore-hole. It is of es- pecial value as -by exactly fitting the hole bored it prevents the drill from diverging from the direction in which it started.

At the Minnesota mine at Tower there are at present six diamond drills at work summer and winter under the charge of Mr. W . H. Cole. They are each run by a portable steam engine with a boiler of ten horse power. A email Blake pump is used with each drill to furnish a continual stream of water which goes to the bottom inside the drill and comes up around the outside, bringing the abraded rock material with it. A pressure of 60 pounds is carried on a 10x12 inch hydraulio cylinder to feed the pump. The drill is pulled out in sections of 20 feet, each of which is un- screwed from the next one. These sections or joints weigh about 50 pounds apiece. The cost of drilling per foot varies from two to eight dollars and averages a little less than three. An average depth of about ten feet a day is drilled now, but the distance used to be much less three years ago.

At Tower the water used in running the diamond drills has been obtained in several instances from an artesian flow struck in drilling the boles. It issues

Iron Ores Of Minnesota. 175

from the. holes drilled on the hill above Soudan. Thus at "KK" hole a good flow of water was struck at a depth of 32C feet This water is clear and cold and has been piped to several of the build- ings where it runs continually, furnishing a fine supply of pure water. It is probably water that soaks into the rock through cracks and crevices and not through some porous stratum.

It is needless to say that it is only since the advent of a railroad to this region that diamond drills could be transported and opera- ated to any extent There are instances, however, where a drill and steam engine have been carried 50 or 60 miles by horses and in canoes and operated at points remote from railroads. Such was the case of the work done on Chub ( Akeley ) lake, west of Gunfiint laka A set of boring apparatus was carried in from Grand Marais and kept at work all of one winter.

The first test-pitting and mining. Some of the early explorers, in addition to the usual light explorer's pick carried along a set of rude hand-drilling apparatus sufficient to bore a hole for blasting. The illustration on plate xx is from a photograph made in the summer of 1889, of the first blast for iron that was ever fired on the Vermilion range. It was done by John Mallmann and Geo. R. Stuntz, on the "south ridge," at a place a little east of where Tower is now located, and near the Lee mine. Mr. Mallmann has kindly given the following statement concerning the exploration:

Mbsaba, Sept. 27th, 1890. Prof. N. II. Winchell:

. Dear Sir.— Your inquiry of the first work done on the Vermilion iron range I received, and in reply will give you the details:

Mr. George Stuntz, John Hoal and William Nana Bushue and myself started from here to Vermilion in July, 1875, and after exploring the Lee hill and the Tower hill, and Jasper peak*, we started the stripping of the ore on the east end of the Lee hill where Mr. Stuntz had first discovered the iron ore during the gold excitement in I860. I was the only miner in the party, and Mr. Stuntz asked me to pnt in a blast in the ore, which was the first blast ever pat in the iron ore of the Vermilion range. I had Indians striking the drills Cor me, and bored a hole about five feet, and threw out a mass of ore which I think you have seen. The last of August, 1875, the party started over to Birch lake, looking over the now Chandler, Pioneer, Zenith and Eaton-Merritt crop- pings, thence up Birch lake to the Mesabi range where Prof. Chester was making his examination.

Yours truly,

John Mallmann.

According to information from Mr. Henry Mayhew, dated Jan. 21, 1886, the earliest real effort at practically testing the rocks at Vermilion lake was made by a party in 1861, consisting of Amos

Thin la sometimes called Chester peak.

17t> BULLETIN NO. VI.

Hall, of St. Paul, Mr. Ely, E. H. Johnson, of Oneota, and Henry May hew, who proceeded to Vermilion lake by the usual route up the St. Louis river, by canoe, in search of gold. They brought down quartz, mixed with slate, that assayed, according to the United States Mint, $19.50 per ton in gold. Nothing more was done about this till H. H. Eames, state geologist, made his report of finding gold at Vermilion lake, and out of it grew the gold ex- citement of 1865 and 1866. It was, as appears from Mr. Mall- mann's letter, the same year that Mr. Stuntz discovered the iron ore ridges at Tower. This discovery, according to Mr. Mayhew, "was scripped by Eames and others. We packed in some 200 lbs. of iron, and shipped to eastern iron men. It proved satisfactory, but was too far from railroads. It was then abandoned till 1868, when J. B. Culver and other parties, with George R. Stuntz, re- surveyed, and with same result, abandoned it for want of a railroad. It lay till the St. Paul and Duluth R. R. was commenced, and the present parties came to the front." This shows the origin of the museum specimens of specular hematite distributed by the Smithsonian Institution in May, 1867, prior to the examinations of Prof. Chester, to which he has referred in his report* as having been sent, with the so-called gold ores, to the Paris Exposition in 1866. These samples were evidently obtained by breaking them by sledges from the natural cropping, as we have no knowledge that any blasting was done in the iron ore in 1866, although there were, near at hand in connection with the gold mining then going on, ample facilities for procuring drills and blasting powder.

The first work of this kind in the region north of lake Superior, as is well known, was not done for the purpose of finding mines of iron, but of silver and gold. Some twenty-five years ago there was quite an excitement over reported gold discoveries in the vicinity of Vermilion lake. Parties of miners made their way to this re- gion with large outfits prepared for mining and assaying. Shafts were sunk and drifts made into the hillsides where quartz veins were discovered. A stamp mill was erected on the stream leading from Trout lake to Vermilion lake, and a great deal of money was wasted in a nearly fruitless search for gold. The remains of these old workings are still to be seen in the piles of refuse and the shafts now filled with water, found in several places around Ver- milion lake.

Methods at the Mines. The lenses of iron ore and jasper tre harder and resist erosion longer than the schists and slates which enclose them. They were found forming large glaciated outcrops

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Iron Ores Of Minnesota. 177

in the highest ridges around Vermilion lake. This made it easy to begin mining the ore, and it was practicable to extract many thousand tons of good ore from open pits or quarries before actual mining operations were resorted to. Such open pits are illus- trated in plates xxi, xxii and xxiii. There is but a thin covering of drift material upon the rocks in the iron ore region, and this is easily "stripped" off. The mines or open pits being commenced on the hills obviated the necessity of pumping apparatus to keep out the water, and for the first two or three years no underground mining was done.

Within the last three years, however, regular underground work has been in operation; and at present there is a larger amount of ore extracted from the dark recesses below the open pits than from those exposed to the light of day. In several cases the fourth, fifth and sixth levels have been started, but few of the mines are yet below the third level. The open pit at the Chandler and hori- zontal entrance to the mine proper are seen in plate xxiii.

The ore in the various pits and shafts of the Minnesota mine at Tower is very hard, and seldom requires timbering to support it. The walls of schist or "soap-rock" are not so firm, and if not sup- ported in some way, slides of rock are apt to occur. In the open pits, which are sometimes more than a hundred feet deep, the walls are kept up by a thin vertical layer of iron ore which is left for that purpose. The mines at Ely are different, since the ore is not so massive, and require some supports.

The ore lenses are vertical or nearly so, and are from ten feet to more than two hundred feet in width, with a varying length and depth, but both greater than the other dimension.

The general method of working the mines is by stopes, pillars of

jasper and lean ore being left to support the floors of the levels

above. In one or two instances a sort of pillar and stall method

is employed, as will be seen from the special description of each

mine. The ore is mostly broken to a convenient size for handling,

in the mines and is loaded into mine cars from winzes and shoots.

These oars are then pushed by hand out to the shaft and hoisted

in cages or on skips in the usual way. Plate xxiv shows one of

these oars; they are so constructed as to dump automatically when

they strike the pocket into which the ore is dropped. Plate xxv

gives a view of an uncovered hoist and a on its way to the

pocket or railroad oar to dump its load. During the winter no ore

eao be shipped by lake transportation, and the product of the mines

during the winter months is dumped into piles or heaps called

stockpiles. Plate xxvi shows the stock-piles at the Chandler mine, -IS

178 Bulletin No. Vi.

containing many thousand tons of first-class ore. Daring the sum- mer the ore is dumped into "pockets" from which it is loaded into the cars by means of shutes. Plate shows one of these pockets* and plate xxvin is a view of the process of loading the cars from the pockets.

Inasmuch as similar methods prevail in all the mines a general description of the apparatus employed will be given here, and a particular account of each mine will be given afterward,

Drills. The diamond drill has already been described. It is used in Minnesota for the purposes of exploration only; not in any way for the operations of practical mining, though there is no par- ticular reason why it should not be so used in certain positions.

The other two kinds of drills in general use are those run by compressed air, called "power drills", and ordinary hand drills, in both of which the boring is accomplished by percussion. The air which runs the power drills is furnished at a pressure of 60 to 80 pounds per square inch in rubber or iron tubes which are connected with powerful air-compressing engines. The Reynolds Air Com- pressors are usually employed, and are manufactured by E. P. Allis & Co., of Milwaukee. The illustration on plate xxix shows one of their double cylinder air compressors. The mining ma- chinery that is being put in at Tower and Ely is of the most im- proved kind and the appearance of the plants at these places is evidence of the fact that they are there to stay, and that the own- ers have perfect confidence in the quantity of ore still in store for future mining.

At the Minnesota mine there were 32 Band compressed air drills (see figure on plate xxx) in use during the season of 1889. They expected to employ double that number in the following season. A uniform pressure of 60 pounds per square inch was used at this mine; but at Ely the drills work under 80 pounds pressure. At Tower two Reynolds compressors capable of running 30 drills each succeeded two Ingersoll compressors of power suf- ficient to run 16 drills each. Various styles of power drills are shown in the cuts, plates xxx, xxxi, . The drills weigh from 250 to 300 pounds each, and the tripod on which the drill is mounted weighs 150 pounds more. Two men are required to run a drill, and the bits when dull have to be taken to and from the forge where they are sharpened by other laborers. The cylin- der of the air-drill is 3 and £ inches in diameter. The average length of a stroke is six inches, and there are five or six strokes made while the bit has rotated through a complete circle. The

IRON ORES Og MINNESOTA. 179

and enlarging

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"Btar bit," fig. 23, is the most common shape. A tool for forging bits is shown in fig. 24 This is commonly called a J "Dolly." The holes vary in depth. For the purpose I of "shaking" the ore, i. e., cracking it ap and enlarging I the receptacle for powder without rending f it into pieces that can be handled, holes are from 16 to 25 feet deep, and in them Giant powder is charged two or three times. Then it is filled with black powder enough to "throw the ore off," — sometimes 60 or 6 kegs. There is a regular period for blast- 1 ing — every three hours, and the sound can be plainly heard for more than forty do. m.— doiij. miles in the direction of the strike of the rooks. The rate at which holes are tared by these drills varies greatly, owing to the hardness of the ore as well as the temper of the drills, the power of the stroke and the skill and experience of the drillers. Some- times a drill will bore ten feet in a day, and again it will not accomplish more than ten inches. The holes are two inches or two inches and a quarter in diameter. The continual clatter made by one of these drills at work underground and in hard ore is enough to distract a person, unused to it, and it is almost impossible to speak Load enough to make yourself heard at a distance of six inches from a person's ear. Plates and XXXIV illustrate the modern methods of sinking shafts and driving tunnels with power drills.

The hand drills are much after the ordinary pattern. They are pointed or sharpened steel bars which are held upright and turned by one man, and driven down by two others with sledges. They usually make a hole one and a half inches in diameter. At the Chandler mine the holes are seldom over 12 feet long. In under- ground work the charges are such as to throw the ore out with one shot. In sinking a shaft eight or ten holes are drilled and charged, and all set off at once by a battery. This breaks up the bottom and facilitates handling the rock. Six compressed air-drills did all the work for the Chandler mine in 1889. Plate is a sectional view of an "Ingersoll Eclipse" drill. Plate xxxva shows the usual miner's candle-stick.

Explosives. An enormous amount of powder and dynamite is used to break np the iron-ore of the Minnesota mine, and consider- able, though not so much, at the Chandler mine. The following

Bulletin No. Vi.

table shows the amount of explosive material used in two or three of the pits at Tower, and at the Chandler mine in July, 1889:

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50 per cent.

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40 per cent.

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35 per cent, giant pow- der.

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10,345 lbs.

410 50-lb. kegs.

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3,060 lbs.

2,800 lbs

50 25-lb. kegs.

13 buu'hs

The cost of this amount of explosive material is no small item, and deducts considerable from the net profit of a mine. The cost, for example, of the explosives, used in the Tower pits of the Min- nesota mine in July, 18S9, was $9,216.16. The amount on hand May 1st, 1889, at the Minnesota mine was as follows:

125,346 caps and primers.

550, 10-foot explosives.

525, 12-foot explosives.

213,544 feet single tape fuse.

73,000 feet double tape fuse.

2 blasting batteries.

400 feet leading battery wire.

12 pounds connecting battery wire.

148 exploders. As might be expected, the fragments of hematite fly with great force and velocity for a long distance, and sometimes do injury to property or persons, but seldom fatally injure any one. A few minutes before the time for blasting, for which all the mines have made preparation, a series of warning notes are given by the steam whistles, and all the miners are expected to retire to places of safety. The ground in the vicinity of the open pits where blasting has been carried on, is covered with pieces of good, fresh ore of all sizes up to fragments 50 pounds in weight Some of them are nearly or quite buried in the earth, having fallen from such a hight. The most serious damage done by these flying pieces of ore, is cutting the wire cables which serve for hoisting. These are covered by boards in the most exposed places; but the damage to them is still said to be considerable. It is of course no slight expense to have an 800 foot cable, an inch in diameter, half bisected by a hematite bullet.

Hoisting Apparatus. The hoisting engines are sometimes in the same plant with the compressors, and sometimes in a separate one. The machinery is necessarily very powerful and complex. A brief description of the hoisting plant at the Chandler mine will

Iron Ores Of Minnesota. 181

ve to illustrate the mode of hoisting in all the mines. The

efts are usually vertical; but there are numerous long inclines

4fcn the open pits. The work of hoisting loaded cars on these is

opened by means of a counterbalancing loaded car of rock or ore,

leh runs down the opposite side of the slope as the dump car,

l which it is connected by a cable, is hoisted up.

i the Chandler mine the hoisting apparatus consists (August,

of two boilers of 100 horse power each, 6 feet in diameter

18 feet long, with a three-eighths inch shell. These are tested

ind 180 pounds of steam. They usually carry 90 to 95 pounds,

the safety valve is set at 97.

!he two cylinders which furnish the hoisting power direct are t48 inches. Each runs at 249 horse power. The hoisting en- run at a rate of 43 revolutions per minute. Large fly-wheels feet in diameter and weighing 8 tons each are used to store up power and equalize the motion of the engines. They save the rer necessary for 7£ revolutions when they are set in motion, cable is wound up on drums of from four to six feet in diameter, illustration of a double cylinder reversible hoisting engine [th fixed drums and double band brakes is seen in plate xxxvi. pattern is made by the Ingersoll-Sergeant company. A sin- drum is used for simple hoisting and lowering of one car or ;e; but a double drum is useful where both lowering and hoist- are desired to be performed at once. Electric lights are used the mines at both Tower and Ely. At the Chandler mine there a dynamo capable of running 18 two thousand candle power ;hts. The dynamo is run by steam and has a 10x14 inch cylin- The dynamo engine runs 300 revolutions a minute and the rnamos over a thousand.

The mines are not very wet, but it is necessary to do some pump-

to keep them dry. Of course some shafts are more liable to be

ret than others. The crushed condition of the ore in'the Chand-

and Pioneer mines allows water to percolate through from the

"surface and makes them wetter than the mines where the ore and

[look are both massive. The cost of mining the crushed ore is not

; to great as that of breaking up and extracting the solid ore; but

[the expense of pumping and timbering is greater. Knowles and

Blake steam pumps are used to keep the water out of the mines

well as to feed the steam engines and diamond drills. These

are ordinary mine pumps and do not require a special description.

Timbering. The cost of timbering is comparatively slight The

ire and walls are both quite firm, and require very little artificial

apport The shafts are generally timbered with square sets and

k. .

182 Bulletin So. Vi.

left without an y casing or sheathing. They are made both single and double, and square or oblong. They are usually sunk in the foot-wall (generally the south wall) about 100 feet from the the ore deposit. A cross-cut is then made from the shaft to the ore deposit at the different levels. The distance from the shaft to the ore remains about the same all the way down, since the rocks and ore are so nearly vertical. Timbers of any size are easily and cheaply obtained, as the property in which the mine is located is frequently covered by a pine forest.

Ventilation. There is usually no lack of good air in the mines, though occasionally a drift or gallery is found where the smoke from the miners' candles, the gases produced by blasting and the exhalation of the laborers have combined to produce a very bad atmosphere. The air which is forced into the mines under pressure to work the power drills, is a great aid to ventilation. Where two or three power drills are constantly at work in a level, open at only one end to a shaft or open pit, the air is kept moderately fresh. The trickling waters, too, absorb a part of the carbonic acid and other gases, and help to purify the air.

Natural means are resorted to, to produce a current of air through some of the mines, as, for instance, the Chandler. The two shafts are connected under ground at the lowest level, Allowing air to pass freely from one shaft to the other. The hoisting frame of the highest shaft is then covered over with boards and closed up so that air can escape only from the top, as from a chimney 50 or 75 feet high. The other shaft is left open at the level of the ground. A regular circulation of air is thus obtained by the draught up the chimney, which draws air down the open shaft and up through the mine. On warm, sunny days the heat of the sun on the air enclosed within the boarded-up shaft house starts up and maintains a notice- able current of air. The lowering and raising of cages is another agent which assists somewhat in changing the air in the vicinity of the shaft.

When the mines become deeper the question of ventilation will become more prominent, and will demand some attention from the mine operators. At present the ventilation almost tftkes care of itself.

Equipment. The frequent outcropping of the iron ore lenses almost or quite on the surface of the ground, makes it a simple matter to begin the extraction of iron ore on a small scale, and a man without any capital can begin to mine iron ore, if he has it on his property, without enlisting the aid of capitalists.

For the operation of a large mine, how aver, an equipment cost- ing a large sum of money is necessary at the outset; and money

Ideal. Leve Of Os

I. LUSTRATION OF A MINE, SHOWING SHAFT, TIMBERING. ELS. HOISTING ENGINES AND AIH COMPKESSOR, WITH METHOD USING POWER DRILLS. HAND DRILL CO.

Iron Obes Of Minnesota.

must be at hand to keep this plant in running order, as well as to pay the employes. To give an idea of the various kinds of ma- terial required to operate a mine like the Minnesota mine at Tower, a list of the machinery in use in that mine during the summer of 1889 is inserted here. This equipment was to be nearly doubled in a year from that time.

Cars, 8kip8 and Derricks. At Pit No. 1,—

4 end dump, 2 ton iron oars.

3 side dump, 2 ton iron cars.

1 end dump, 1 ton wood car.

1 one ton bucket.

1 cage.

At Pit No. 3 —

12 end dump, 2 ton iron cars.

3 end dump, 1 ton wood car.

1 two ton skip. At Pit No. 5.—

6 end dump, 2 ton iron cars.

1 end dump, 2 ton iron car.

1 one ton skip.

1 cage.

At Montana shaft, —

1 one ton bucket

1 end dump, 1 ton wood car.

At Montana pit, —

6 end dump, 2 ton iron cars.

2 side dump, 2 ton iron oars. At No. 6 Pit,—

8 end dump, 2 ton iron oars.

1 side dump, 2 ton wood oar.

1 cage. At Alaska shaft, —

1 end dump, 1 ton wood oar.

1 one ton skip.

1 cage. At No. 8 pit,—

17 end dump, 2 ton iron cars.

1 end dump, 1 ton wood oar.

1 one ton skip.

1 cage. At No. 9 scram,—

3 end dump, 2 ton iron cars.

1 end dump, 2 ton wood car. At No. 9 pit,—

2 one ton wood cars. 2 one ton buckets.

At No, 17 scram,—

1 end dump, 2 ton iron oar. 1 end dump, 1 ton wood car.

At No. 19 scram, —

1 end dump, 2 ton wood oar. At No. 1 stock-pile, —

2 wooden box stock- pile cars. At No. 2 stock pile, —

1 wooden box stock-pile car. At No. 3 stock-pile, —

2 iron stock-pile oars,

1 end dump, 2 ton iron car, 5 wooden stock-pile cars. At No. 5 stock- pile, —

5 iron stock-pile cars.

At No. 7 and No. 8 stock-pile,— 8 iron stock-pile cars. 1 wooden stock-pile car.

At No. 9 stock-pile, —

6 wooden stock-pile cars,

1 iron stock-pile car. At No. 16 stock pile,—

2 wooden stock-pile cars. At No. 17 etock-pile, —

2 wooden stock-pile cars. At No. 19 stock-pile,—

3 wooden stock-pile cars.

At No. 10 pit,—

4 end dump, 2 ton iron cars,

1 side dump, 2 ton iron cars.

2 1-ton iron buckets, 1 cage.

At No. 11 pit,—

1 turntable iron car.

At No. 10 stock-pile,—

4 wooden stock-pile cars.

At Yard,—

5 1 ton iron buckets.

1 1 ton skip.

At general blacksmith shop,—

2 2 ton iron cars. 1 cage.

4 derricks. 4 hoists.

184 Bulletin No. Vi.

Machinery. No. 1 Engine,—

1 portable boiler on skids.

1 20-ft. hoisting drum with 6x8 engine. No. 3 Engine, —

4 6 f t . hoisting drums with ten 18x24 engines.

2 3}4 ft* hoisting drums with two 10x12 engines. 2 5x16 boilers.

1 No. 5 Knowles feed pump. No. 4 Engine, —

1 No. 3 Knowles pump .

1 3J£x 11 Allis feed water heater.

2 4 ft. drums with 14x20 engines.

1 20 foot portable hoist.

3 air receivers.

2 20x30 Ingersoll air-compressors.

3 5x16 boilers, with No. 5 feed pump. No. 6 Engine House, —

2 5 ft. hoisting drums, with engines.

1 20 ft. portable hoist, with engine.

2 3J£ ft. hoisting drums, with engine. 2 5 ft. hoisting drums, with engine.

2 5x16 boilers, with No. 6 Knowles pump.

1 feed water-heater. No. 7 Engine,—

1 No. 7 Ames locomotive boiler.

1 5 ft. drum with engine. No. 8 Engine,—

1 new Economizer locomotive boiler.

1 No. 1% Blake feed pump.

2 20 ft. portable hoists.

Armstrong Engine House, —

1 upright boiler. At lumber yard, —

1 3x6 upright boiler.

1 5x16 boiler.

2 4x16 boilers.

Engine Houses. 8 engine houses, various dimensions.

Other Buildings. Warehouses, change houses, heating houses, barns, blacksmith shops, ice- house, laboratory, post office, general offices, hospital, pest-house, shoeing shops, shipping offices, electric light plant, repair shops, drill shops, lumber office, powder houses, time offices, dwelling houses, etc.

Diamond Drills. 1 Economizer loco boiler, 10 horse power. 1 No. 4 Ames loco boiler, 12 horse power. 1 No. 3 Ames loco boiler. 8 horse power.

1 B Sullivan diamond drill, 2,000 feet.

2 Bullock champion drills, 800 feet 1 Bullock " Beauty " drill, 500 feet.

Iron Ores Of Minnesota. 185

100 Karats carbons. 2 No. Blake pumps. 2 WorthingtoD pumps.

Oils.

6 oil tanks.

4,516 gallons kerosene.

820 gallons miner's oil.

1,111 gallons block oil.

675 gallons Eagle machine oil.

107 gallons vacuum cylinder oil.

150 gallons common cylinder oil.

93 gallons spring oil.

200 gallons lard.

900 lbs. axle grease.

600 lbs. patent grease.

150 gallons Eldorado oil.

Fuel. 810 tons steam coal. 16 tons egg coal. 124 cords soft wood. At Two Harbors,—

3,145 tons steam coal. 250 tons Blossburg coal.

Steam Pumps. Swamp pump.

1 upright tubular boiler, 7 ft. 9 in. 1 No. 6 Know lee plunger pump. 1 tank, 6 \000 gallons . 1 No. 6 Knowle9 pump.

1 B mining pump.

6 No. 6 Knowles pumps.

2 No. 4 Knowles pumps. 1 No. 6 BUke pump.

1 duplex Knowles pump. 1 No. 6 Dayton pump.

7 tanks, various sizes.

Machine Shops. 1 Locomotive boiler, with No. 4 Kaowles pump 1 engine, 11x16.

1 88 inch lathe, with 2 running blocks.

2 18 inch lathes.

1 Peerless pipe-cutter. 1 Walcott shaper. 1 bolt-cutter. 1 drill-press.

Wire Rope. 5V867 feet 1% inch wire rope. 8J979 feet % inch wire rope. 2,668 feet inoh wire rope. ifiVl feet 7-8 inoh wire rope. 8*97& feet 1 inoh wire rope.

186 Bulletin No. Vi.

Miscellaneous.

17 shafts.

10 shaft houses.

8 coal docks and pockets.

Explosives, see page 180.

Assay laboratory at Tower.

Assay laboratory at Two Harbors.

The cost of these various adjuncts to a mining plant may be stated approximately as follows:

Gars, skips and derricks $16,000.00

Machinery 66,000.00

Engine houses 5,000.00

Dwellings 64,000.00

Other buildings ! 32,000.00

Air pipes 5,238.00

Electric lights 5,000.00

Supplies 72,000.00

Oils 3,000.00

Fuel 32,000.00

Machine shop 8,000.00

Blacksmith shop 12,000.00

Laboratories 4,000.00

Pumps Ac 8,000.00

Wire rope 4,000.00

Shafts Ac 36,000.00

Total cost of plant $372,238.00

The cost of explosives at Tower is several thousand dollars per month, and the other materials which are used up cannot be esti- mated exactly. The number of miners employed in these mines is sufficient to form a small city. During the summer of 1889 there were more than 1,600 men employed at the Minnesota mine, and 650 at the Chandler. In 1890 the Minnesota Iron company intended to enlarge their force to 2,000 men. At the Chandler mine the ore extracted is about a ton and a half a day per man. At the Minne- sota mine it is less, and is about one and one- tenth tons per man. This is due to the greater amount of drilling and breaking neces- sary in the hard ore of the Minnesota mine. The pay-roll at the Minnesota mine is over $70,000.00 a month.

Methods of sampling and analyzing, and quality of the ore. In asmuch as the Minnesota Iron company's land is considerable, and ore is taken from pits which vary in their content of metallic iron and of phosphorus, it is necessary to keep a close watch on all the

Iron Ore8 Of Minnesota. 187

ore that is mined in order to have it properly graded. The ore is hand-picked into three grades, by men who can tell at sight when a piece of ore has too much quartz in it to belong to a certain grade. It is pretty well known what kind of ore is being obtained from each pit. One pit or mine may vary considerably in the per cent of metallic iron, but not usually in the per cent of phosphorus.

The ore is sold by contract according to grade. There were six grades of ore sold in the season of 1889, as follows:

Vermilion, 66.66 per cent, to 67 per cent. Fe., High Phosphorus.

Soudan, 65.00 per cent. Fe., High Phosphorus.

Bed Lake, 62.00 per cent Fe., High Phosphorus.

Minnesota, 66 66 per cent. Fe., to 68 per cent. Fe. Low Phosphorus.

Braddock, 65.00 per cent Fe., Low Phosphorus.

Nipigon, 62.00 per cent. Fe., Low Phosphorus.

" High Pho3phorus " means that the ore contains over six hun- dredths of one-percent, of phosphorus, and is above the Bessemer limit "Low Phosphorus" means that the ore contains less than hundredths of one per cent, of phosphorus, and is adapted for making JBessemer steel* No regularity has been discovered in the general trend of phosphorus streaks. Outside samples, (i. e. samples from the outer edges of ore-lenses,) and inside samples were analyzed, but did not show any constant difference. In one lens there would be more phosphorus in the outside ore thau in the ore from the interior of the mass; in another lens the reverse 'would be found to be true.f

The general character of the ore from a pit is quite constant, end at the Minnesota mine the nature of the ore in the various pits is as follows:

Pit No. 1 is high phosphorus. (Stuntz mine).

Pit No. 2 is low phosphorus. (Old Stone mine).

Pit No. 3 is low phosphorus. (Old Stone mine).

Pit No. 4 is low phosphorus. (Old Stone mine).

Pit No. 5 is low phosphorus. (New shaft).

The role usually adopted for determining whether any iron ore Is to be ranked as Dew einer is as follows: The figures standing in the places of hundredths and thou- sandths, In the decimal expressing the percentage of phosphorus, must he, taken together as an integer.no higher than the integer that expresses the percentage of metallic Iron in the ore. Thus, the following would be Bessemer ores: Fe. 08.44, P. 0.0JT: Fe. 44.10, P. 0.033; Fe. 68.43, P. 0.011; the following would not be Bessemer ores: 9*. 68.44, P. 0.060; Fe. 30.45, P. 0.041.

" In a series of twenty-three samples taken from lumps of ore along seams, the phosphorus was determined in the Interiors of the lumps and in the scale along the faces. In erery sample of non-Bessemer ore the phosphorus was higher in the lump than in Che scale, and In Bessemer samples the scale was considerably higher t han the lamp, with the exception of three eases in which tho scalo was lower by .003 percent., cent, and .006 per cent, respectively, (100 per cent. - .whole sample, not phos- .") C. T. Walert, (In a letter dated June 27, 1800.)

Bulletin No. Vi.

Pit No. 6 is low phosphorus. (Old Ely pit).

Pit No. 7 is high phosphorus. (Tower mine).

Pit No. 8 is high phosphorus. (Tower mine).

Pit No. 9 is low phosphorus. (West Tower mine).

Pit No. 10 is high phosphorus. (Lee mine).

Pit No. 11 is low phosphorus. (East Lee).

Pit No. 12 is low phosphorus. (Too much sulphur). (Breitung).

Pit No. 13 is high phosphorus. (West Breitung).

Montana is low phosphorus.

Alaska is high phosphorus.

The amount of each grade of ore mined and shipped between December 1, 1883, and August 1, 1889, from the Minnesota mine, is as follows. All but 12,797 tons of this was shipped between April 22, 1889 and August I, 1889:

July shipments. Previously reported,

Total

1 a

o

B

a

Os

Cd

Co

co

O

P

M

H3

O

a

S

ex

1,501

11,165 14,713

50,781

3,877

8,228

4,407

21,207

22,-285

90,302

10,082

22,906

59,476

32,372

36,998

|141,0&3

13,459

31,134

Cs

103,669 210,853

314,522

From this table it may be seen that considerably more than half the ore mined is low in phosphorus, and that nearly half of it con- tains over 65 per cent of metallic iron and less than six hundredths of one per cent of phosphorus. Such a showing can probably be made by no other mining region in the world.

The theoretical per cent of metallic iron in pure hematite being but 70, it leaves less than 5 per cent to be accounted for as impur- ities. This is mainly silica, in the form of quartz. Sulphur is rarely found in quantities sufficient to be determined. The amount of phosphorus is the all-important thing, and in order to be sure of this the ore is analyzed three times, once at the mine, once at Two Harbors and once at the blast furnace, before it is smelted; and the steel goes through further processes of chemical analysis.

Sampling and assaying. A chemist and one or two "samplers" are continually employed to make these determinations. The min- ers put the ore in stock-piles, in pockets or in cars. The sampler then goes to these stock-piles or cars with a hammer and bag. With a tape-line or a string he goes diagonally or lengthwise across a car load, taking a small piece of whatever the knot, which he has made in his string every 12 inches, falls on. It may be jasper or

Iron Ores Of Minnesota.

rock or ore. The samples from one or more cars, sometimes as many as six, are ground up and pulverized, first under a steam crusher, and then by hand, care being taken to keep samples from different mines separate. After this ore has been dried in a steam bath the chemist takes a certain portion of it, about 5 grains, and determines the per cent of iron and of phosphorus. Duplicate samples are generally worked so as to make no mistake. The silica is not usually determined by actual tests, bat can be ascertained by the method of differences. The methods of volumetric analysis given in Blair's Chemical Analysis of Iron are usually employed with occasional slight variations.

When a new pit is opened or a new level commenced complete analyses are made of the ore. These seldom show any great varia- tion.

The reports from these analyses are carefully made and as care- fully examined by the general manager or superintendent of the mine. The amount and kind of ore mined from each pit and shipped from each pocket is recorded in the record books of the laboratory and on tabulated slips as follows. The analyses below are given simply as samples of the chemists' reports:

Pocket No. 5, Braddook Grade.

Date.

Jane 6, 1889 Jane 11, 1889 June 22, 1889 June 28, 1889

No.

Metallic iron.

Phos- phorus.

Remarks.

2 oars.

2 oars. 4 oars.

3 oars.

Pocket No. 5, Minnesota Grade.

Date.

Jra* 5,1889 June 10.1*89 1011022,1889 June 26. 1889 JMM2R.18H9

Metallic iron.

Phos- phorus.

Remarks.

3 care. Scars. 6 oars. 2 cars. 5 care.

Bulletin No. Vi.

Pooket No. 9, Nipigon Grade

Date.

No.

Metallic iron.

Phos- phorus.

Remarks.

June 1. 1889

3 oars.

June 5. 1889

1 car.

June 5, 1889

2 cars from No. 2 stockpile.

Pocket No. 9, Minnesota Grade.

Date.

No.

Metallic iron.

Phos- phorus.

Remarks.

June 5, 1889

2400 I

2 cars.

Junell,1889

4 cars.

June 15, 1889

4 cars from No. 1 stockpile. 4 cars.

June 25, 1889

At the end of each month averages are made which show what amount of ore has been furnished by each mine or pocket during that space of time and what the quality of it was. Below is given the average for July, 1889:

Minnesota Grade.

Mine. Fe.

No. 5 Pocket 67. Ml per cent.

No. 9 Pocket 67.783 per cent.

No. 2 Pocket 65.517 per cent.

Ilraddock Grade.

No. 5 Pocket 63.325 per cent.

Nipigon Grade.

No. 2 Pocket 59.20 per cent.

No. 3 Pocket 64. CO per cent.

No. 5 Pocket (52.175 per cent.

Vermilion Grade.

No. 1 Pocket 67.45 per cent.

No. 7 Pocket 67. 15 per cent.

No. 8 Pocket 67.57 per cent.

No. 19 Pocket 66.166 per cent.

Soudan Grade.

No. 1 Pocket 66.213 per cent.

No. 7 Pocket C7. 108 per cent.

No. 8 Pocket . . 65.088 per cent.

No. 13 Pocket 60.50 per cent.

Red Lake Grade.

No. 1 Pocket 62.55 per cent.

No. 7 Pocket 66.80 per cent.

No. 9 Pocket 61.15 per cent.

No. 10 Pocket 63.00 per cent.

No. 13 Pocket 62.15 per cent

. 0544 per cent. .0393 per cent. . 0455 per cent.

.053 per cent.

.052 per cent.

. 121 per cent.

.0605 per cent.

.085 percent.

. 173 per cent. . 1219 per cent. . 1344 per cent.

.0553 percent.

. 1578 per cent.

.0993 percent.

.145 percent.

.0793 per cent. . 167 per cent. .053 per cent. 114 per oent. . 104 per cent.

Oars

Shipped.

.

Iron Oee8 Of Minnesota. 191

If a certain grade of ore has been a little too high in phosphor- us for one month, better ore than the guarantee calls for is shipped in that grade the next month, and the required average is maintained.

Distribution of phosphorus in the ore. Mr. David H. Browne, after a careful examination of the ore of the Ludington mine, Iron Mountain, Michigan, with reference to its content of phosphorus in different parts of the ore bodies, reached the conclusion that ore high in phosphorus was niDst prevalent near the hanging wall, decreasing toward the foot- wall, and that in lenses that pitched west the ore at the eastern end contained more phosphorus than that at the western end, and that, in general, ore from the levels near the surface contained more phosphorus than that from greater depths. The ore here is a soft, friable, bluish-black hematite, oc- curring in thin laminaa which cleave very readily from each other in the direction of the strike. These layers alternate, in places, with thin seams of calcium-magnesium carbonate. He says:

"The fact that phosphorus exists as calcium phosphate led me to infer that some proportion between the percentage of lime and phosphorus might be found to exist, but such inference was not verified in practice. An ore containing 2 per cent of lime may contain almost no phosphorus, or may run high above Besse- mer limit, nor was any proportion manifest between the percent- ages of iron or silica and phosphorus. I have noticed jasper vary as much in percentage of phosphorus as any iron ore, and simi- larly a lean ore is just as likely to be Bessemer as non-Bessemer. The only difference I could find between Bessemer and non-Besse- mer was this: As a rule a soft blue hematite high in phosphorus has a brighter and more specular appearance than non-Bessemer ore of the same value in iron. This distinction, slight as it is, will not always hold good, and the separation of such ores must be guided solely by chemical analysis."

It will not be warrantable to apply these statements unquali- fiedly to any mine except that which Mr. Browne examined. We are led to suspect that the Ludington ore, and the formation in which it occurs, may not be paralleled by the Vermilion range ores of Minnesota, but rather by those hematites found in the Mesabi range.

Still, in order to make some comparisons with the exploited ores of Minnesota, Mr. 0. T. Waters has conducted some chemical re-

♦ Am. Jour. Sol. (311) . 300.

192 Bulletin No. Vi.

searches having in view some of the same problems, and he has kindly furnished the following statement giving some of his results:

Soudan, Minn., Oct. 30, 1890. Prof. N. H. Winchell, Minneapolis:

Dear Sib. — In speaking with you, we referred to Mr. Browne's paper on the occurrence of phosphorus in the Ludington mine. He speaks of the " bright blue hematite " as being high in phos- phorus, but says he can not grade the ore as Bessemer and non- Bessemer without chemical analyses.

At the time his paper was published, I had been for some time looking for a method by which we could separate our ores, with some degree of certainty, without recourse to analysis.

I found that while in most cases I could determine with reason- able accuracy the per cent of phosphorus by the shade of color of the powdered sample, the method was not sufficiently reliable to warrant its use.

I find that the proportions of iron, silica, etc., in quantities of our ore seems, as Mr. Brown states also for the Ludington ore, to have no connection with the amount of phosphorus, although in 34 instances of determination made in the gangueon the face of seams and in the clean ore behind the face— with three or four exceptions, in which the phosphorus in gangue and clean ore were nearly the same, (about .060 per cent. ) — I found the gangue of Bessemer ore to contain more, and of non-Bessemer ore to contain less phosphorus, than the clean ore.

By Bessemer, I mean what we ship as Bessemer, that is, .055 per cent, and below, of phosphorus. My conclusion as to blue ore is the opposite of Mr. Browne's. I used for examination the powder prepared for analysis. The red ore which is brighter, runs higher in phosphorus than the blue ore, which is duller but seemingly of a finer texture. The blue powder packs closer and gives a smoother surface when rubbed down with a spatula.

These observations apply more to our first class ores (68.00 to 68.50 Fe. about,) than to our second and third classes (65.00 and 62.00 Fe.), which in Bessemer ore are more brown than blue.

There is a marked difference in the color of the powdered ore from the, different workings; that from non-Bessemer pits being very red, and that from Bessemer pits being quite blue.

After becoming accustomed to the peculiar shades of color, it is possible to say, nearly always, from what pit a given sample is, and whether it is higher or lower in phosphorus than any other sample from the same working.

Iron Obes Of Minnesota. 193

I should say that the amount of phosphorus does not influence the shade and color of these ores, but that the variations of shade and color are due to the same causes as is the variation in phos- phorus. All this applies, of course, only to our ores here.

I have tried, qualitatively, five samples of so-called ''soap rock"

for manganese. They were from the following: 1. Tunnel at

East Breitung. 2. No. 7 shaft, 25 feet from the ore body. 3.

Railroad cut near the Stone pocket. 4. Butte shaft, 60 feet from

ore body. 5. Montana shaft, 75 feet from ore body. Of these,

numbers 1 and 4 were the only ones which gave me indications of

any manganese. These two I started to work quantitatively, but

did not complete, as there was in five grains so small a precipitate

of the oxide that it would be almost indeterminable.

Tours very truly,

C. T. Waters.

Descriptions Of The Separate Mines.

The Minnesota Iron Company. The condition of the excavations is constantly changing. Some idea of the various openings that had been made at that date was conveyed to the public in the an- nual report for 1886, with illustrations of the shapes at the surface and to the first, and sometimes the second level. Great changes have taken place since then. The pits are all deeper, and in some have been continued downward to the fifth and sixth levels. They have baen extended east and west, both as open pits and especially in under ground working. At the same time some of the original excavations, having been abandoned as open pits, are slowly being filled again by dumping of the rock and refuse from the other pits.

From Mr. H. A. Wilcox the depths of the principal pits were ob- tained (Oct. 1890), and from captain Williams general estimates of the underground excavations on the various levels.

Shaft No. 1, (Stuntz), is 238 feet deep; has three levels, one at about 100 feet, one at 170 feet and the third at the bottom. On the first floor work has been extended about 300 feet in each direc- tion (east and west) from the shaft; and on the second about 150 feet each way. On the third floor work has been prosecuted about 60 feet each way from the shaft. These drifts, which have the width (north and south) of the ore body, average from 13 to 15 feet wide.

Shaft No. 2 (east end of the old Stone mine), has been abandoned, but was perhaps 75 feet deep.

Shaft No. 3 (Stone) is 367 feet deep, and has six floors. The

irst is at a depth of 117 feet, the second at 147 feet, the third at

194 Bulletin No. Vi.

197 feet, the fourth 217 feet, the fifth 267 feet, the sixth at the bot- tom, 367 feet below the surface. On the first level the working has gone from 500 to 600 feet between the extreme ends, with a width of about 20 feet, average. On the second level the work has gone about 150 feet east, but not any west; width about 20 feet. On the third level the working has been extended 250 feet west and 75 feet east. On the fourth floor it has gone 100 feet to the east, but on the west the ground is left for future working. On the fifth floor the work is 200 feet toward the west, and about 100 feet toward the east. On the sixth level it is extended 35 feet, and here the ore ceased in that direction. On the west the work is at about 150 feet from the shaft. Between the fifth and sixth floors the ore body pinched out, at least ceased; and the ore was found, and is now be- ing worked, on the sixth level, about 30 feet further to the south, and is about as wide as before. The upper portion of this new ore was shaped like a hog's back, and at first was accidentally encoun- tered in sinking the shaft in the rock of the south wall. It is ap- parently a new lens.

Shaft No. 4 was an open pit at the Stone, now tributary under ground with No. 3; not recognized.

Shaft No. 5 (East Ely, or east end of the Ely) is 364 feet deep. This is connected with No. 3 at the third level. The floors are at about the same places as those of No. 3. On the first floor it is ex- cavated about 1Q0 feet each way; on the second floor 75 feet toward the west and 175 feet toward the east. On the third floor it is con- nected on the east with No. 3, and on the west, at 200 feet, is connected with No. 6. On the fourth floor nothing has been done toward the east, but toward the west about 150 feet have been taken out. On the fifth floor the excavation has been carried about 75 feet toward the east, but not at all toward the west At the bottom working has been carried about 25 feet east, and about 15 feet west.

Shaft No. 6 (Ely) is 230. feet deep, and is an open pit down to 130 feet. It has two floors. On the first floor the extreme ends are 150 feet apart. On the second floor the working has extended about 100 feet on the west, and on the east there is a connection with No. 5.

Shaft No. 7 (new East Tower) is 259 feet deep, and has four floors. The first floor is down about 113 feet, the second 153 feet, the third 203 feet, the fourth 259 feet. On the first floor the work- ing has extended about 250 feet, from east to west, extreme length; on the second, in like manner, about 150 feet, and on the third

Iron Obe8 Of Minnesota. 195

about 100 feet. At the fourth level the ore is not yet reached iu the cross-cut from the shaft.

Shaft No. 8 (old East Tower) is about 310 feet deep. This pit was worked, open, down to about 150 feet. The next floor (first floor) is about 50 feet below, and work has extended about 300 feet between the extreme ends. The second level is about 50 feet lower, and the excavated interval between the extreme ends (east and west,) is about 175 feet The third level, which is 65 feet lower, is not yet worked. The cross-cut from the shaft is simply in the ore.

Shaft No. 9 (West Tower) is 350 feet deep. This was worked as an open pit to the depth of about 300 feet At the depth of 200 feet a drift was worked westward, underground, 150 feet. The next floor is at the bottom. A drift has been run here toward the west, in the footwall (i. e. the southern wall), about 14 feet, not any east; not yet in the ore.

Shaft No. 10 (North Lee, sometimes called West Lee,) has a depth of 135 feet, and is worked as an open pit, with an extent east and west of about 200 feet

Shaft No. 11 (old South Lee, sometimes described as East Lee) is abandoned. There was no real shaft. Ore and rock were hoisted with a derrick from an extreme depth of perhaps 75 feet

Shaft No. 12 (Breitung, situated toward the west, across the spur- track, southwest from the irregular main old Breitung), has an estimated depth of 150 feet. The first floor is down 117 feet, and runs west about 25 feet, none east The second floor is not yet reached by the shaft now being sunk.

Shaft No. 13 (part of the old Breitung, south of the west end of the West Tower), is 147 feet deep. Open pit 87 feet There is one floor below, worked about 150 feet between the ends.

Alaska shaft has two floors, and is 287 feet deep. One floor is at 180 feet from the surface, and is extended about 150 feet west, none east The bottom floor, 47 feet lower, is extended about 180 feet or 190 feet east and west. The shaft is down about 60 feet be- low that.

Montana shaft is 249 feet deep, and has two floors; one is at the bottom of the open pit (viz. at 109 feet) and the other is at 75 feet lower, on which work has been extended 300 feet east and west. Seventy feet still lower working has extended about 20 feet be- tween extreme ends.

Butte shaft is 150 feet deep and has two floors. At the depth of 100 feet a cross-cut was put in from the shaft to the ore, but no mining has been done there. At 50 feet still lower they put in a m gat and struck the ore again. No mining has been done.

196 Bulletin No. Vi.

Armstrong shaft, which is 150 feet deep, has been worked only so far as to drift in at the bottom and strike the ore.

All the east-and-west workings would have an estimated average width of about 25 or 30 feet. In No. 8 shaft, however, the working is in some places 50 or 60 feet wide. There are numbered work- ings running to about 20, representing small pits and scrams, some- times worked by contract by " scrammers."

The Chandler mine. This mine is now operated by the Minnesota Exploration Company. When parties of the survey first visited the location of the Chandler mine* (or Patterson's trenches) in July 1886, they found several north-and-south trenches from two to six feet in depth, running, as supposed, across the ore bed. The bot- toms of the trenches were in a red, soft earth which was supposed to be hematite ore in situ. A close inspection was made along the bottoms and in the earth thrown out, and the owners were told the material was not in situ, but had been moved and mingled with a little/drift material, and was indicative of a deposit of soft ore in the near vicinity. It proved subsequently that the main deposit from which the red earth was largely derived, was situated about seventy-five feet further toward the north, and on it the first ore was taken out in an open pit. The railroad did not reach the Chandler property till late in the season of 1888 and the amount of ore shipped that year (54,612 tons) shows that the ore was easily mined and that the management of the mine did a good season's work in a very short time.

During the following year the major portion of the output came from this open cut, although underground mining was commenced and considerable ore was raised through the two shafts now known as Nob. 1 and 2. The season of 1889 closed giving the Chandler mine the credit for the production of 316,120 tons of a high grade Bessemer hematite. This for the second season's work is the best record gained by any mine in the lake Superior district. All of the ore shipped from the Chandler mine has been raised through two vertical, two-cage shafts. Shaft No. 2 is located about 370 feet west of the boundary line between this property and the Pioneer, and 190 feet south of the north line. This shaft is 300 feet deep. Shaft No. 1 is 720 feet west of No. 2 and about 200 feet south and is 250 feet deep. The formation is generally nearly vertical and the ore body has a pitch to the east of about thirty degrees. This with one or two exceptions is the situation of all the ore bodies in this region and while the walls of the deposits have positions vary-

See the fifteenth Annual Report p. 325-86.

Iron Ores Of Minnesota. 197

ing from the perpendicular to nearly horizontal, the pitch remains about the same.

The mode of mining employed here is what is known as the cav- ing system. The levels are all made sixty feet apart, and in the ground lying above the floor drifts, cross-cuts and raises are driven in such directions as to leave blocks of ore which are afterwards milled down into the tram cars, pushed to the cage and raised to the surface. This ore is at first taken from the blocks at the ex- tremities of the body opened up and worked out towards the shafts* the surface being allowed to fill the cavity thus made. In case of poor ground being met with, it is, if of larger dimensions, left standing and allowed to follow the surface on its downward course* while the small bunches of rock are removed to the foot, or hang- ing wall sides of the deposit Here they are out of the way and save the cost of raising to the surface and tramming out to the rock pile. By this process practically all of the ore can be removed and at a minimum cost Bat very little timber is used in the under- ground workings as all the drifts and cross-cats are carried as nar- row as possible and it is only when very soft ground is cut that timbering is found necessary.

The ore body has a length on this property of about 900 feet, and would possibly average seventy-five feet in width. It is not at all regular and in places it is not over fifteen feet wide and again across- cut will give it a width of 150 feet. (See fig. 15.) The foot and hang- ing walls are both plainly marked and seem to be of about the same kind of rook, commonly known as greenstone. West of the open out and of shaft No. 1 the green rock outcrops in several places and either forms a crossing, catting out the ore in this direction or tarns it toward the south. The former theory seems to be the most plausible one, however, and the one which stands in favor among the mine operators. Two levels are now being opened up below those that have thus far been worked.

All the hoisting is done by four drums, requiring but two brake- men on a shift to handle the four cages. These drums are six feet in diameter and are made by Webster, Gamp & Lane of Chi- cago. This plant is operated by one of E. P. Allis' double engines of the Corliss pattern, having cylinders 18x43 inches. (See plate XXIX.) With this plant during the past twelve months over 350,- 000 tons of ore have been raised. This is a better record than can be shown by any other plant in the region for the ame length of time. In the same building an Allis compound compressor furnishes air for the operation of eight power-drills. (See plate xx,A.) This machine has a 17x36 inch live steam

198 Bulletin No. Vi.

cylinder and a 24x36 inch cold steam end, and air cylinders 15x36 inches. An Allis feed water beater furnishes water to the boilers, which are located in another part of the building. The bcilers are of the return-flue pattern, 6 feet by 18 feet, and develop about 125 horse power each. These boilers, of which there are three, form one battery and can be used together or individually as necessity requires. Ordinarily two boilers are sufficient to furn- ish steam for the pumps in No. 1 shaft and the engines above de- scribed. Near No. 2 shaft a 4x16 ft. boiler and two smaller furnish steam for the pumps in No. 2 shaft. These pumps are of a special pattern, having No. 10 water ends and No. 11 steam ends. This style of water pump has been found to be the most economical, and is in general use at many of the mines. The company has a pri- vate electric light plant consisting of an eighteen-arc-light Brush dynamo, propelled by a Ball 11x10 inch engine, and besides furn- ishing light for all of the shaft houses and ore pockets, etc, around the mine, one of the large general stores in the town is illuminated. In looking over this property, the fact impresses itself on the ob- server that the managers are thorough mining men and know how to operate a mine. Everything is in its place, the machinery is well kept, and all the buildings well suited for the various duties for which they are designed, and the amount of ore mined and shipped gives evidence that the underground work is well looked after. Ihis property is operated by the Minnesota Exploration Company, with Joseph Sellwood genera) manager, Jno. Pengilly superintendent, and Capt. Scadden as mining captain. One of the many interesting features of this mine is the fact that it occu- pies only forty acres, and the ore is taken from half of that forty.

The Pioneer mine, under the direction of Superintendent Mc- Quade, has two shafts, sunk on the south side of the ore in what is called the foot wall, one 200 and the other 175 feet deep. The deeper one has three levels; the first is down about 60 feet, the next 75 feet lower, and the last 75 feet lower still. There has not yet been any working east and west on the first floor. On the second level there is simply a cross-cut to the ore, and but little ore has been taken out. On the third floor it is the same. The cross-cuts increase in length downward, showing a dip north. On the surface the ore is about 75 feet from the shaft, and at the bottom, 200 feet down, it is about 125 feet from the shaft. This is No. 2 shaft and is sunk all the way in broken jasper. The greenstone begins to appear in the foot wall at the bottom, but at the surface was 75 feet south from the shaft. No. 1 shaft has been so far in a "broken

Iron Ores Of Minnesota. 199

up jasper and paint rock." This has two floors, one down 100 feet and the other 175 feet. On the first floor the ore was too narrow to work and on the second floor the mining has progressed west about 75 feet, and is now being pushed upward on the ore toward the first floor.

The history of this mine since ore was first discovered in it has shown that the mineral has been found in bunches. Id places these deposits would be of fairly large dimensions and in others hardly large enough to pay for their removal, showing conclusively that the formation was in an unsettled state and that it would become more regular as depth was attained. The company is con- vinced of this fact and intend to sink the shafts deeper this coming winter, 1890-91, and in the meantime to remove all the ore that is opened up and place it in the stock piles.

The mine is well equipped with all the machinery necessary for carrying on their work. In the engine house an 80-horse power boiler, bearing the mark of Gogebic boiler works, Duluth, furnishes steam power for three pumps and the hoisting apparatus, consisting of a double four-foot drum hoist of the Marinette iron works man- ufacture. The engine house, blacksmith shop, "dry" and office are well built, comfortable structure* and dressed in a neat coat of paint, presenting a creditable appearance.

During the past two seasons there have been shipped from the property 15,116 tons of high grade Bessemer hematite; of this amount 12,016 tons should be credited to this season's output.

The mode of mining employed here is not materially different from that of any of the other range mines. The nearly perpendic- ular character of the formation makes a vertical shaft the most practicable, and here in both the shafts cages are employed. The ore is shoveled into the tram cars from the drift, cross-cut or room down in the mine, pushed out onto the cage at the shaft, hoisted to the sur face, trammed out to the end of the trestle, and dumped in the stock pile. The trestle running from No. 1 shaft house is elevated to a hight of about thirty feet above the ground and is about 300 feet long, giving ample room beneath for a large stock pile. No. 2 is not as well arranged for stocking purposes, but a new and larger shaft house is designed and will probably be built this fall or winter. Other improvements are contemplated, among which, and probably the most important, is the sinking of a shaft on the western end of the property. This shaft will be located about 500 paces north of the section line and about 100 paces or 265 feet east of the Chandler line. Between No. 2 shaft and the wost boundary line of the property, a distance of 1,600 feet, the ground is practi-

200 Bulletin No. Vi.

cally unexplored, and it is reasonable to suppose that valuable deposits of ore exist there, and will be opened by the new shaft A diamond-drill hole was put down a short distance north of the location of this shaft and passed through some forty feet of clean ore. There is but little doubt that the Pioneer mine will, in the near future, develop into one of the valuable range properties.

The Zenith mine, next east of the Chandler, has been employed wholly in exploratory and dead-work — test-pitting, shaft-sinking and diamond-drilling.

As at most all of the other properties now being explored on the range considerable work in the line of running trenches and dig- ging test-pits was done on what is known as the Zenith property prior to the date of the present company's taking possession. Just what this labor amounted to in the way of determining the value of the property or the locating of the ore vein is not known, but judging from the appearance of the rock from these workings seen in the dump piles, nothing but the jasper "cappings' was en- countered.

Shaft No. 1, or the first one put down by the present company, measures about 6x9 feet inside, and is located 727 paces north, and 750 paces west of the section corner. This shaft is vertical, and located in jasper and other rock, the first fifty feet being sunk in the "capping" and soap rock, and the remaining twenty feet in a good variety of ore. At the depth of fifty feet a cross-cut to the north found the ore to have a width of fourteen feet, and a similar one from the bottom gave the deposit a width of nearly twenty-four feet, showing that thb body is widening out as depth is attained. A drift has been driven west for a distance of thirty feet, and a cross- cut started south to connect with the working shaft for the purpose of ventilation.

Shaft No. 2 is also vertical, being carried down 7xl4J feet, inside measurement. This is to be a two-cage shaft, and is being sunk in the foot wall greenstone. Its present depth is forty-eight feet, and up to the time of this writing, all of the hoisting has been done with a windlass. The location is 710 paces north, and 760 paces west, or about 30 feet west and 46 feet south of No. 1. A Bullock diamond drill is being used on the property and has been the means of proving up the value of the eighty, as much, if not more, than the shafts just described. The hole now being worked is lo- cated 687 paces west and 850 paces north of the southeast corner, or about 370 feet north of No. 2 shaft and 190 feet east. The drill rods were given a pitch of 45 degrees to the south and the first 105

Iron Ores Of Minnesota. 201

feet was drilled in jasper when about 6 feet of ore and soaprock was cat The next 91 feet showed ore and jasper mixed, the major portion being ore; daring the following 67 feet of drilling the core barrel brought up clean ore, then came 17 feet of ore and jasper and at the bottom 325 feet from the saf face the drill appears to be cutting greenstone. After finishing this hole the drill will be moved 400 feet farther west and 100 feet north.

Until recently (October, 1890, ) no surface improvements of any kind were made on this property, but at piesent a large force of carpenters and mechanics of various kinds is employed on build- ings for numerous purposes and other surface work. An office and warehouse combined and a blacksmith shop and "dry" are already occupied; a little farther east a boarding house 26x76 feet, two stories high, and across the county road a barn of ample size are fast near- ing completion. Back on the foot- wall, between the west line of the property and No. 2 shaft a large 100-horse power boiler of the Iron Bay company's make is being bricked in, and close to it the foundation for a hoist is being laid. This machinery also comes from the Iron Bay Co., and is one of their double five foot drum- plants having 12x16 inch duplex engines. Over this outfit will be erected two buildings 28x50 feet and 20x40 feet respectively. A force of fifty men is at present employed by the company under the charge of Capt. Nick Cowling.

Still further east are several other workings and valuable iron properties, but none have shipped any ore. The railroad has not been extended to them, but probably will be in the near future.

The Anderson Iron Company has commenced work about a mile southwest from Ely, and a vertical shaft is being sunk (on the N. j£, N. W. U and S. E. % N. W. % sec. 4, 62-12,) but has not yet (October, 1890,) reached the rock. Several trenches and test- pits have been dug, and they show very nearly the same indica- tions of ore as were encountered at first at the Chandler mine — via: red earth, occasional clean soft hematite lumps and some high grade hard ore nodules. It seems quite likely that the ore body of which the owners are in search, lies somewhat further north, and will be found by drifting from the shaft in that direction.

The machinery on the ground consists of a small portable hoist, a No. 4 steam pump and about a 25 horse-power locomotive fire-box bailer. A force of about twelve men is employed here and suitable eampa have recently been erected for their accommodation. A boiler and engine house and blacksmith shop complete the surface improvements.

202 Bulletin No. Vi.

At this place several other reputed iron properties are adjacent, owned by Messrs. James, Camp and Bouchleau, which again are ad- jacent to the Lock hart location which adjoins the Chandler. In general the region is swampy, comprising two or more parallel val- leys, and the ore is supposed by Mr. Camp not to be a part of the Chandler ore body, nor associated with it, but to run E-NE toward section 25. These valleys are separated by ridges of gray wacke- greenstone which are nearly continuous and rise from 20 to 30 feet above the valleys. Most of the pits and trenches show mixed green and red slate, or schist, (being a condition of the greenstone) with varying amounts of hematite mingled with chalcedonic silica. Some of the pits, which were full of water at the time of the exam- ination which could be partially judged of by the dumping, showed plainly a soft, clean hematite in considerable quantity, and judging by this the ore body seems to be extended over a width of several hundred feet, including interruptions of rocky strata. The ore is entirely brecciated, resembling that from the Chandler mine.

There is, in this same region, a narrow magnetic belt which is so marked that on crossing it the dip needle stands vertical over a space of a few (8 or 10) feet. This ore is represented by No. 1513.* This belt has been traced out by Mr. Camp for about a mile. It winds about aod across this land. A shaft was sunk to it The ore is apparently also graphitic. It is simply a part of the same formation that the hematite is in and stands in thin, vertical, irreg- ular jaspilitic sheets. One sample (1619) showing a loadstone po. larity, was stated by Mr. Camp to have been obtained from this magnetite deposit The peculiarity of this is that its color of streak is reddish, not black, indicating a magnetic hematite.

The Stone mine is at Mesaba, on the Duluth and Iron Eange railroad — Mallmann's original working, f It is now under charge of Capt. Bice, who has sunk one shaft to about 120 feet. The last rock thrown out is that mongrel, siliceous, chalcedonic mixture, or " feldspathic rock" which is characteristic of the Taconic (Animike) in this region, and which might be called a variable quartzyte, lying above the main portion of the Pewabic quartzyte.

The Mallmann mine proper is on NE# of section 11, township 59, range 14, in the place where Prof. Chester made some examin- ation for iron about ten years ago (See the eleventh annual report). A line of railroad levels has just been run (October, 1890,) from

This magnetic character is known at the Eaton-Merritt property four miles east of Ely, and seems to increase further east. It prevails in T. 63-9. A similar magnetic belt occurs at Tower, running through the swampy ground between Tower and Soudan, and was penetrated by drill GG, at a depth of 200 feet from the surface.

+ See the eighteenth annual report, page 7.

Iron Ores Of Minnesota. 203

Mesaba station, which is on SW5j£ of section 21, township 59, range 14, to this mine, preparatory to extending the track for the shipment of ore. The station is 909 feet above lake Superior. The highest point found was near the mine, (at station 199) and is 1,141 feet above lake Superior.

This mine is in the Taconic, and presents the characters of the mines on the Gogebic range in Michigan and Wisconsin. The rocks dip southeast conspicuously, about 30 degrees. There is a foot wall of quartzyte (the Pewabic quartzyte), and an overlying wall of black slates.* No green-stone dykes are known in the vicinity, but not enough is known yet to warrant a general state- ment of their non-existence. The ore is hematite, vesicular, or soft, and is plainly the bedded formation, showing all the flexures and variations in texture and dip that the enclosing rocks show* It is rather allied in its lithological affinities, as shown by the encroaching impurities, with the quartzyte which underlies, being in that part of the quartzyte (the upper part) which elsewhere has been seen to be hematitic and rotting or rusty, or magnetic. The underlying quartzyte, toward the top, and especially where it begins to hold some ore, is chalcedonic quite noticeably.

The working here has not yet been extensive, but enough has been done to disclose the existence of a large and valuable bed of hematite. There is a vertical shaft 60 feet deep, the last thirty of which, as stated by the owners, are in ore. Here it struck the foot wall. A cross-cut south was then made 92 feet, the last 85 feet of which were in good shipping ore. Other shafts and pits show the ore at a depth of 20 to 25 feet below the surface.

The interesting geological fact about this locality is not so much the opening up of a new field, and demonstration of the iron-bear- ing quality of the Taconic on the north side of lake Superior in such light that it seems likely to rival, when exploited, the same on the south side, but rather the fact that here the graywacke-green- stone of the Keewatin, identical with that seen at Ely, is found in immediate proximity standing vertical, or presenting shapeless knobs such as characterize it south of Long lake. Here it embraces the so-called "silver" vein to which Prof. Chester referred in his report f in 1883, the enclosing rock being a rather fine-grained*

The thickness of the black slates Is not known, but in sec. 34 (NWi, 50-14, near the northwest corner of the section. Mr. E.J. Longyear drilled in them 800 feet and did not penetrate through them.

t Bee the eleventh annnal report, p. 150, The writer re-visited and looked again over the same old dump material at this silver " pit, as in 1S78. The rock was before called quartzyte, and samples brought away are quartzyte (442). Chester also speaks of the quartz vein cutting horizontal beas of quartzyte. But at the recent visit a cursory examination showed some of the to be a greenish schist like the Keewatin. This may have come from the Keewatin which ruav have been reached at the bottom of the pit.

Bulletin No. Ti.

tn

O

m

eo

Taconic

Black

Slate.*

re olfk*.

HllHt.

8fC

avAfnuyrg K£EWAT1H

iGrCUjWCUCkt

range.

ran

tf.

Keewat*/*

Fio. 26. —Generalized section at the Mall- man mine.

greenish, somewhat slaty gray- wacke showing evident sediment- ary structure more perfectly than most of the gray wacke about here. The interest of thisKeewatin local- ity is increased by the existence of promising iron deposits, a jaspery hematite, near the center of section 11, which rises 10 to 15 feet in an isolated low ridge running about 15 rods. It is surrounded by Kee- watin greenstone, and the structure is approximately vertical. Prof. Chester also made reference to this in his report, regarding it an anom- alous occurrence in the midst of a country of nearly horizontal mag- netitic quartz. It is scarcely neces- sary to say that this jaspery ridge of hematite has nothing to do with the ore of the Mall m an n mine near which it occurs, but has its allian- ces with the ore mined at Tower. The adjoining diagram shows the geological relations of these two ore masses, and strengthens the intimation that, as already stated in this bulletin, similar contrariety and variety occur in the two for- mations at Negaunee, Mich. It is highly necessary, in any future working that may be conducted on the Mesabi range in the exploitation of the iron ores, that these two formations be kept, distinct, since the ores occur in different rela- tions to the enclosing rocks, and will require different methods of mining

The McComber mine is situated at Armstrong lake, about midway between Tower and Ely. Some exploratory work with a diamond

IB0H OBBfl 07 MINNESOTA.

drill, and otherwise, has been carried on here for a few years.

Mr. MoComber states that the drill passed through good ore 12 feet and 18 feet thick. Hisshaft which is 60 feet deep, is now having a drift made to the ore. He has already taken oat about 300 tone of high grade ore, and the prospect is that it will ship several thousand tons in the sea- son of 1891.

The Diamond mine is at the extreme western end of the Mes- abi range in Bee. 15, 66-24, and in the same formation, as well as in the Bame strati graphic posi- tion, as the Mallmann mine de- scribed above, and exhibits the same lithological characters. There has not yet been found here, however, any portion of the Keewatin on the south side of the Giant's range, and it is presumed that at that place the granite continues southward be- low the Pewabic quartzyte. Some account of this mine was given in the eighteenth annnal report, pp. 16-19, based on a visit to that place in 1888. At that time suffi- cient information was not at hand to establish the relation of the Pewabic quartzyte to the black slates of the 'laconic, and that point was left in donbt Since then the slates have been found to lie above the quartzyte. At that time three shafts had been sunk to the ore, the deepest being 47 feet. No great amount of merchantable ore had yet been fonnd, but since then it is reported thatoreof good quality B.M.-KMdnwadthicti0ntbroUBhand ;n ]arge quantity has been

206 ' Bulletin No. Vi.

found in that region. The Duluth and Winnipeg railroad runs within about ten miles of this mine, but there is no branch yet tiuilt to it The following section, figure 26, north and south through this mine shows the geological relations.

At numerous other points considerable exploratory work has been done both on the Mesabi and on the Vermilion range, and some of these other locations might be classed as mines.

The Mountain Iron Company, on S. J, S. E. i, and S. J S. W. ± sec. 34, 59-18, have a diamond drill at work, in the Keewatin. Ore that affords 61 per cent, metallic iron was met at the depth of 38 feet.

J. M. Longyear has been working a diamond drill on the N. W. J of sec. 34, 59-14, near the southwest corner, also at a point further north, and in the latter place is reported to have ore similar to that in the Stone mine.

Langdon, Conkey and Warren (of Minneapolis) have some working on sections 31 and 33, 64-9.

There are numerous other places where work has been done, sometimes at little expense, and sometimes involving thousands of dollars. But as they are either unknown as to exact location, or have resulted in nothing of economic importance there is no need of enumerating them. On the accompanying geological map all known localities of iron ore are denoted by a bright red color.

Part Iii.

Transportation Of Minnesota Ore.

All of the product of the Minnesota iron mines is shipped in the first instance by rail to Two Harbors (formerly known as Agate bay) on the north shore of lake Superior. It is then loaded on barges which carry it by the waters of lake Superior, St. Mary's river, lake Huron, St. Clair river, lake St. Clair, Detroit river and lake Erie to the lake ports of Buffalo, Cleveland and Toledo. Some of the lake Superior ores also stop at Detroit, or, passing westward on entering lake Huron through the strait of Mackinac, they follow lake Michigan to Chicago.

The Minnesota Iron Company, being the pioneer enterprise in the actual mining of these ores in Minnesota, took simultaneous measures for their transportation and their mining. By means of an auxiliary corporation, known as the Duluth and Iron Bange railroad company, after the donation by the State of Minnesota of a generous grant of public land, the railroad was completed from Two Harbors to Vermilion lake in 1884, and a year or two later was extended to Duluth where it made its terminal connection with the Northern Pacific and other railroads that center at that point The location of the road is shown on the accompanying map. Its profile of elevation is shown by plate , extending from Du- luth to Ely. The elevation of lake Superior is 602 feet above the sea. Tower Junction is 775 feet higher or 1377 feet above the sea. The ridges in which the mines are located at Soudan rise to the extreme hight of about 1600 feet above the sea, but they are generally about 1650 feet above the sea. The mines are opened on their summits, and by hand-cars which run over the trestled tramways to the "docks" or "pockets", the ore, after hoisting, is conveyed to the railroad. It here descends rapidly through the pockets, or is dumped immediately into the ore-cars (compare plates xxv, xxvi and xxvii) which sta jd convenient near the pockets, or docks. In this operation the ore descends from fifty to one hundred feet be-

Bulletin No. Vi.

low the summits of the hills. The ears are then yarded and made into trains by the switch engines, at a level about fifty feet still lower. One of these ore-cars, when empty, is shown on plate xxxviii. It has three compartments, tte sides of which slope like a hopper toward the bottom, and they are unloaded by an arrange- ment which allows the bottom to dropout in the manner of a dredge, bucket* These ore cars carry an average load of about twenty tons (their capacity being twenty-five tons) and when made up into* trains the separate trains, when full, contain twenty-two cars. The powerful engines which haul these trains are from the Bald- win Locomotive works Plate xxxix represents one of them.

The following table shows the operations of this road for the first six years:

Statistics ofDuluth and Iron Range Railroad.

L' of road (miles) Passengers carried . . Passengers carried

one mile

Tons freight moved. Tons freight moved

one mile

Earnings.

Passenger

Freight

Mail and Express — Miscellaneous

Total

Expenses. Maintenance of way

Rolling stock

Transportation

Miscellaneous

Aug. 21 to

Dec. 31,

Total.

3,225

103,388 73,700

4,561,581

$0,609.30

110,806.14

4,088.12

$ 134,853.65

$ 15,500.17

6,580.00

27.705.44

16,020.47

4,784

280,265 258,725

17,582,548

$ 14,463.25

258,637.54

Per cent

Net earnings.

Surplus

Cost of construction and equipment (steel rails, 61 lbs. per yard)

Train Mileage.

Passenger trains —

Freight trains

Total.

$66,013,17

$ 68,840.48

38,100.04

2,531.507.23

$247,400.45

$ 45.432.10 15.321.70 53.Ktf.08 37,155.12

6,823

418,500 366,620

24,813,017

$20,407.28

361.410.07

3,113.33

1,500.35

$ 386,521 03

$36,766.07 20,374.76 81.560.64 40,801.41

$ 152,165.00

$122,244.26

Deficit

17,021.07

2,436,282.71

35,585 04,388

120,071

$ 170,606.78

$ 206,014.25

61,834.15

2,062,101.28

40,756 120,745

170,001

33,985

1,547,732 493,246

33,150,304

$66,203.23

512,356.07

3,188.00

$582,030.50

$ 64,586.35

103,000.30

53.640 67

61.058.56

$ 284,103.88

$207,836.62

132,602.83

7,170,210.26

78,053 104,414

273,367

70,780

1,670,650 627,416

42,857,084

$ 65,520.01

577.568.60

4,878 02

2,120.17

$650,088.60

$83,120.87 156.238. 1H

78,100 12 61,475.70

$ 370,033.87

$271,054.73

42,464.16

8,221.068.36

111,221 241,386

400,754

102,846

2,012,180

887,502

64,838,604

$ 77,368.66

704.550.15

2,480.04

7,706.81

$ 886,518.7ft

$ 06.604,41

112.350.66

ZH,i>TdM

50,801.16

$ 404,010.11

$303,400.65

135,515.01

0,247,152.04

110,735 315,156

502,667

Duluth and Iron Range R. R. Chartered Dec. 21, 1874. State swamp-land grant, ten sections to the mile. 96.3 miles completed December, 1886. Road opened from Two Harbors to Tower (67.6 miles) Aug. 2L, 1884; from Tower to Ely (21 miles) Oct. 1, 1888.

♦These cars are manufactured by three different firms: The Lafayette Oar Works* Lafayette, Ind.. Haskell & Barker Oar Co.. Michigan City, Ind., and the Wells-Freneh Oar company. Chicago, 111. They do not differ materially in style.

iv '"'111 r'

s

r

'

a

Iron Ores Of Minne80Ta. 209

Boiling stock in use. Deo. 31, 1888. June 30, 1889.

Locomotive engines 27 34

Passenger oars 7 10

Combination oars 2 3

Baggage, mail and express 2 2

Caboose, Ac 15 20

Boxcars 60 50

Stock cars 2 2

Platform cars 304 303

Coal cars 15 15

Orecars 480 738

Total : 862 1143*

Transportation of iron ore.

Freight rates.

From Ely to Two Harbors, per ton $1.00

From Tower to Two Harbors, per ton 75

From Two Harbors to Cleveland, per ton 1 .35

From Ashland to Cleveland, per ton 1 .25

From Marquette to Cleveland, per ton 1 .25

From Escanaba to Cleveland, per ton 1. 10

Dockage charges, (not chargeable against the ore.)

At Two Harbors $ .04

At Ashland 04

At Marquette 04

At Escanaba 04

At Cleveland 04

Unloading at Cleveland (paid by the vessel) 18

Freight rates by rail:

From Ely to Two Harbors, per ton $1 .00

From Tower to Two Harbors, per ton 75

Ishpeming or Negaunee to Marquette, per ton

Ishpeming or Negaunee to Escanaba, per ton 70

Hurley to Ashland, per ton 70

Facilities at Two Harbors. There are two large ore-docks at Two Harbors. The dock No. 1 was erected in the summer of 1884, and is 1,200 feet front, extending into Agate bay. Its north side has a pocket frontage of 1,000 feet, and the south side a frontage of 985 feet, devoted to loading of cargoes. The total aggregate front- age is 2,400 feet, with a 1,925- foot front devoted to the loading of vessels. Within this frontage, there are on the north side of the dock 88 pockets, and 74 on the opposite front, giving a total of 162 pockets, having a total capacity of 16,000 tons. The water adjoin- ing is from 17 to 21 feet in depth, and the dock itself is about 47 feet wide by about 50 feet high.

The No. 2 dock has a total length of 1,200 feet, and a total water front of 1,925 feet, of which 1,625 feet is devoted to pocket room, the north side having 600 feet front and 53 pockets, while the loath front has 1,025 feet provided with 88 pockets. The gross frontage for this side is 1,200 feet, and for the north side 725 feet,

Poor's manual of railroads.

210 Bulletin No. Vi.

making a total of 1,925 feet. The dock has 141 pockets, of J ,800 tons total capacity. This being the more recent dock, it is provided with larger pockets. It was constructed in 1885.

It is proposed to erect a third dock, south of the No. 1 structure, at some future time, placing the new one, or the No. 3 dock, some 200 feet away. It is to be constructed of iron and steel, and will increase the frontage devoted to the ore business some 2,100 feet, and the tonnage all of 20,000 tons, or probably 25,000 tons, which would then show for Two Harbors a frontage of 5,650 feet, and a tonnage capacity, of 59,000 tons.

The present breakwater is 550 feet long and 1,275 feet from the end of dock No. 1 and 1,270 feet from the end of the proposed or No. 3 dock.

There is also shown on the map a projected breakwater in line with the present one, from the opposite side of Agate bay, which is to be 1,025 feet long, leaving an entrance between them of 1,725 feet, which, with the 550 feet of the present ore and the distance of 120 feet that it is away from shore, makes a total of 3,420 feet, the width of the bay at this point. The bay, when the proposed breakwater is completed, will include all of one square mile of area The end of the proposed structure is 1,325 feet from the dock No. 1.

Two general merchandise docks are maintained, one of 404 feet length and a second of 379 feet long, having between them a slip of 400 feet long by 100 feet wide — the docks themselves being 50 feet wide. The west dock has a frontage of 735 feet and the east one, used as a coal dock since 1888, has a frontage of 475 feet, upon which there are employed three rotary hoists in conjunction with hoppers overhead, which admit of loading direct to railroad cars or of conveying to the large storage space of 125 feet by 425 feet They can handle 800 tons of coal per day of ten hours with three rotary hoists.

The lake carriers. The capacity of the canal at Sault St. Marie limits the size of the cargoes of some of the larger boats that carry lake Superior ore, and in general larger cargoes leave the docks at Escanaba (a lake Michigan port which is the southward outlet for ore from Negaunee) than any of the lake Superior ports. The following, however, cleared from Two Harbors the third week in October, 1890: Manola, 2,343 gross tons; Matoa, 2,336 gross tons; Maruba, 2,311 tons; Mariska, 2,281 tons; J. C. Lockwood, 2,179 tons; Alex Nimick, 2,105 tons; Gladstone, 1,971 tons; Sibe- ria, 1,898 tons; Hesper, 1,881 tons; R. P. Flower, 1,776 tons; J. S. Fay, 1,319 tons and D. P. Rhodes, 1,529 tons. These are all large

Iron Ores Of Minnesota. 211

lake Superior loads, but one of the "McDougal boats," barge 107, carried 2,698 gross tons through the canal a short time before.

By far the greater portion of the ore output is got to market by these large lake carriers, whose owners are often interested in the ores they carry, and in the mines that produce them. They have season contracts, at rates that enable them to make somewhat regular trips, or they are required to take the output under such restrictions that their rates are susceptible of being maintained against competition of "wild" freighters. This gives greater sta- bility to the markets and security to the producer, although, in some exceptional cases the rates of the "wild" freighters are less.

Future transportation routes. In the event of the development of our iron ore industry further west, say between Duluth and the Mississippi river, whether it be in the conversion of ore to steel by charcoal process or not, there can be no doubt that the Mississippi river itself will become the chief avenue of transportation, and that the coals of Iowa and Illinois will be the objective points. There is no cheaper way of transporting freight like iron ore than by water, and there are no cheaper water-ways than rivers and canals. The route from Grand Rapids on the Mississippi by river to points near the coal fields of Illinois and Iowa, would compete success- fully with that by lake from Two Harbors to Cleveland. The Mis- sissippi is navigable without improvement between Grand Rapids and Aitkin, and between St Paul and the gulf of Mexico. There lire rapids and water- falls between St. Paul and Aitkin where locks and canals would have to be constructed.

Market prices of iron ore.

There is from year to year a fluctuation in the market prices of iron ore, due to causes that are similar to those that modify the prices of other commodities, viz: Depression in the general finan- cial conditions, over-production, or scarcity of ready ore at epochs when it is specially demanded. Sometimes the element of lake transportation has operated to enhance the value of ore at Cleve- land, there having been insufficient lake tonnage, necessitating shipment all the way by railroad, and sometimes dockage facilities have been wanting. Prices in 1889 were very low, almost the lowest ever known, but in 1890 they were from $.50 to $1.00 per ton higher. The best lake Superior ore sold, in 1890, from $6.00 to $7.25 per ton. The Bessemer hematites generally reached $6.50 per ton. Ttje standard, hard, non-Bessemer hematites, such as the Vermilion grade of the Minnesota Iron Company, sold at $6.00 per ton. Soft, non-Bessemer ores, with from 59 to 60 per cent of iron. old for $125 to $4.50 per ton.

212 Bulletin No. Vi.

Profits.

The net profit of a successful iron mine is often very great, in proportion to the money invested. There is a large amount of money lost, it is true, in fruitless investigation, but it is small compared to the income from the successful mines. It is impoe- sible to ascertain the precise average cost of mining iron ore per ton. The mine owners are chary about divulging the statistics that indicate their profits. Some facts, however, which are known and others which may be estimated, afford us an approximation to the result of a year's work. It was attempted to ascertain, from official sources, the average cost of mining a ton of iron ore, and to dis- tribute this cost, at the respective mining points, among the items that go to make the cost— such as explosives, labor, machinery and timber, repairs, etc., but the attempt had to be abandoned. It is only when, by law, mining companies and all similar corporations are required to keep open books, showing their expenses and re- ceipts, that a reliable statement can be made of the profits of min- ing iron ore.

Some of the soft Bessemer hematites on the Gogebic range have been mined at a cost of about $.75 per ton in large quantities, but that was when the ore was so near the surface and so abundant that it required but little more that the excavation and the shovel- ing of the product into the cars, which, in this case, were run even into the side-hill where the ore was found. In general, however, the cost of mining the soft ores is much greater. At Ely it has been estimated at $.90 to $1.00 by some of the officers not inter- ested in the Chandler mine, but it probably is somewhat greater, and may be supposed to not exceed $1.25 per ton. This, of course, does not include transportation from the mine.

At Tower, the expense of mining the harder ore is correspondingly greater, and at the same time the company has entered upon ex- tensive and expensive improvements, and on investigations by the use of the diamond-drill in order to learn the extent and the posi- tion of the ore bodies. Proportionately the net profits are less at Tower than at Ely. Estimates of the cost per ton at Tower, by non-interested parties, placed it at $1.55 to $1.65, but we have reason to believe it is nearly $2.00, allowance being made for all im- provements and explorations, and for depreciation of the property, the life of the plant being considered fifteen years.

The net profits, based on these figures, and allowing for cost of transportation to Cleveland, amount to about one million dollars for the mines at Ely, since they were opened in 1888, and about five millions of dollars for the mines at Tower since 1884.

Part Iv-

Origin Of The Ores Of Iron.

Chrowth of theories— An examination of the literature giving the different views advanced during the last half -century to account for the formation and accumulation of iron ore deposits reveals the fact that there has been a gradual evolutionary change in the opinions of geologists. With the growth of geological science and with improved methods of research and the consequent increase in particular and exact knowledge of the natural forces at play in the destruction and construction of rocks and minerals, there has been an accompanying revision of ideas formerly held, some of which now appear to us more or less crude and unsatisfactory. This re- vised opinion is not universal among geologists as yet; but the majority of recent writers and the preponderance of opinion seem to have been tending toward results that were very little anticipated thirty or forty years ago.

tfThen the facts of the universal distribution of iron and of the many different ways in which it is acted upon by all the transmut- ing agencies which continually surround and involve it are taken into consideration, the wonder is not that there is such a complex- ity of theories and such conflict of opinion, but rather that there is 00 large an agreement as there is, and so few theories advanced to account for its accumulation in large deposits. It is astonish- ing, however, to any one who has noticed the many ways in which iron oxides are produced and transported from place to place, to find reputable and learned geologists advocating in their writings one single method of origination and accumulation for all ores of whatever age, or however varied in chemical composition and physical characters. Yet such will be seen to be the case in several remarkable instances.

Before the various phenomena of metamorphism had become generally understood and while plutonic forces were assigned on every hand as the cause of all things not easily explicable other- wiae* it was natural enough that deposits of iron ore should have

214 Bulletin No. Vi.

been universally considered veins, connected at an unknown depth with a parent mass in the interior of the earth. Bat when in a thousand cases these so-called veins had been mined out and proven to be isolated, lenticular masses, without any deep-seated connec- tion, and when we consider that the oxide of iron, if fused with the accompanying "gangue," would have produced anything but de- posits of good iron ore, we should expect that no geologist in recent times would have the rashness to revive and reassert the old idea of igneous veins composed of hematite or magnetite, with a gangue of jasper or acidic feldspathic rocks; yet there are several notable examples of just such wild speculation and argumentation. The ten- dency of geologists in general, however, has been away from the igneous and sublimation theories, towards those based on sedimen- tary or combined chemical and sedimentary forces. It is true that some of the very early geologists, both in this country and in Europe* advocated a sedimentary origin for some or all of the iron ores; but they were rare exceptions to the general rule and their views met with very little favor.

Whereas, in the seventeenth century, no distinction was made by those who attempted an explanation of the existence of ore deposits, between those of iron and those of gold or silver, or lead, or any other kind of ore, there has been a process of differentiation in the last two hundred years similar to that which has been witnessed in nearly all cases of continued investigation. There has been a specialization in observation which has resulted in discrimination among the various kinds of ores. Some were found to present dif- ferent physical structure and surroundings. Some were differently constituted chemically, and differently allied to the rocks in which they exist. An important distinction was made when iron ores were considered separately from the other metals, and were inves- tigated independently. Another important distinction was made when the metalliferous fissure-veins were distinguished from metal-bearing strata or isolated lodes or lenses. There has been a continual descent from the complex to the simple and single, both in general geological conception and observation, and in the theory of ore-origin. The general complex idea has been, to a certain ex- tent, separated into its single and individual components. There is need of still further specialization. Iron ores as a group cannot be lumped into one hypothesis to explain them, although there have been several notable recent efforts at that result. They must be separated from one another, and each must be investigated independently. The necessity for special examination of each iron ore deposit, or at least for each class of iron ores, whether they

Iron Ores Of Minnesota. 215

be classed chemically or stratigraphically, has been recognized by some, bat not by the majority of recent writers. There is nothing that the present authors desire to enforce more emphatically than this, as a result of their study.

A summary recital of the earliest views of the genesis of ore de- posits will illustrate this evolutionary change.

Early views of the origin of ore deposits. In Werner's classical treatise, "A New Theory of the Formation of Veins/' the various views held up to the year 1789 are mentioned and outlined. These views have been quoted by Yon Cotta and Phillips in their treatises on ore deposits and by John Taylor in the Report of the British Association for 1833;* and an abstract from that one of them which is more concise and clear will be used here, without any further reference to the place where the exact language quoted may be found.

Georgius Agricola, whose real name was Bauer and whom Wer- ner calls the father of mineralogy and of the science of mining, was the first to propound a theory of veins in his work De Ortu Et Causis Subterraneorum (1546.) In this, the principal agents ware, water, which dissolved the enclosing rock, heat, and cold. In , accordance with the state of science at that time, he considered the metals to have been formed from other substances and deposited from solution in water. He considered the then prevalent belief that lodes are of the same age as the globe itself "an opinion of the vulgar."

TJtman, Elterlein, Meier, Ltthneis and Barba are passed by in contempt by Werner, as they attributed the richness or poverty of veins to such absurd causes as the position of the mountains with respect to the sun, and the influence of the stars.

Bossier, who died in 1673, regarded veins as fissures previously listing in the rocks and subsequently filled with minerals.

Beoher (1669) ascribes the formation of metals and minerals to subterranean vapors which penetrated the veins and produced a peculiar change in their earthy and stony constituents.

Stahl (1700) considered the lodes to have been formed in the enclosing rock at the time the world was created.

Henkel (1725) attributes the formation of ores in lodes to a pe- culiar exhalation produced and engendered by a "fermentation" supposed to take place in the interior of rocks. The vapors pene- trated earths and rocks suitable for a matrix.

Hoffman (1738) supposes lodes to have been formed in the fis- sures of rocks.

alto Gad. Cornwall, Devon and W. Somerset, De La Beche. 1839, p. 349, et leg.

216 Bulletin No. Vi.

Lazzaro Moro held the same opinion and believed them to have been filled with molten eruptive matter. This seems to have been the earliest statement of this view.

Zimmerman (1746) supposed the veins and the ores in them to have been produced by a transformation of the substance of the enclosing rocks; this alteration being assisted by certain saline sub- stances which prepare and render the earthy matters capable of being changed into metalliferous minerals and their accompanying vein-stones.

Yon Oppel (1749) explains the veins distinctly as subsequent fillings of original fissures, and thus separates them from beds and strata.

Lehmann (1753) first mentions Hoffman's hypothesis, and then adds, that the lodes are the branches and shoots of an immense deposit situated at a prodigious depth in the bowels of the earth. He compares the lodes to the branches of a tree. From this cen- tral manufactory of the metals they have made their way into the fissures in a humid and gaseous condition.

Delius (1770) considered the vein-fissures to be a consequence of the contraction caused by the drying up of the earth. The rain water penetrating the rocks dissolved the elements of the rocks and metals and conveyed them into the fissures, where by subsequent evaporation they crystallized out.

Charpentier (1778) agreed essentially with Zimmerman's theory, which he carried still further.

Baumer (1779) says: "The lodes differ in form and matter from the rocks; from various data it follows that they were formed ui* der the ancient sea, since the out-croppings of the same are often covered with several layers of schist; and petrifactions of sea-spe- cies have at times been found, as well in the geodes they contain as in the lodes themselves."

Gerhard (1781) like many others, considered the lodes to have been formed by a metamorphosis, in consequence of a kind of fer- mentation and decomposition caused by water and heat. He sup- posed further that water penetrating the country rock dissolves certain substances, and afterward passing into vein fissures there deposits the minerals which it previously held in solution. These minerals, he is of opinion, existed originally in the adjacent rocks, and have been carried in a state of aqueous solution into the fis- sures, where they are now found in the form of metalliferous veins.

Yon Trebra (1785) ascribes the origin of metalliferous lodes mainly to the action of "putrefaction and fermentation." He ap- pears to regard the two terms as synonymous, and subsequently

Iron Ores Of Minnesota. 217

defines the latter as "the quality which, acting by insensible de- grees, produces the most perfect transformation in the bowels of the earth."

Lasius (1789) considers veins to have been formed in rents pro- duced by revolutions of nature, and these he believes to have been afterwards filled with water containing carbonic acid, which thus acquired the property of dissolving various earthy and metallic matters contained in the rocks through which they percolated. By reason of various precipitants these pubstances were afterwards deposited in the fissures in which they are now found. He, how- ever, is not so clear as to whether the metallic particles were al- ready present in the substance of the rock, or were formed in them by the action of water upon minute "metallic seeds."

Werner (1791) developed his own views on the subject at consid- erable length. He believed that all true veins were originally rents and were subsequently filled with mineral matter from above. Bents or fissures have been produced by various causes and at very different periods. Mountains were formed by a successive accum- ulation of different beds upon one another; the resulting mass was at first wet and possessed of little solidity or coherence, so that when the accumulation had attained a certain hight it yielded to its own weight, sank, and cracked, or the rocks on an exposed side, as toward a valley, separated from the rest in consequence of the contraction caused by drying, or the shock of an earthquake, as- sisted by gravitation. "The vein-stuff arose from a wet precipitate which filled the fissures from above, that is, from a wet and mostly chemical solution, which covered the region where the rents ex- isted, and filled the open fissures."

Although Werner claimed to be the author of the idea of the successive formation of veins and of their relative ages, it seems that an Englishman, Dr. Wm. Pryce, in a work entitled "Miner- alogia Cornubiensis", published in 1778, had advanced the same idea at length. Dr. Anderson, Werner's translator, believes that this work was unknown to Werner, since he was so uniformly fair and just in giving every man credit for all he believed.

Werner's theory was very generally accepted and held for 25 years or more. During that time, however, various modifications or even substitutes for it were proposed.

Hutton (1795) advanced the idea of igneous injection of vein material. This theory had been briefly stated in 1740 by Lazzaro Iforo, but is generally known as Hutton's theory. Hutton argued very strongly in bis Theory of the Earth, that " Veins are of a for- mation subsequent to the hardening and consolidation of the strata

218 Bulletin No. Vi.

which they traverse, and that the crystallized and sparry structure of the substances contained in them shows that these substances must have concreted in a fluid state. This fluidity was simple, like that of fusion by heat, and not compound like that of solution in a menstruum. It is inferred that this is so from the acknowledged insolubility of the substances that fill the vein in any one mens- truum, and from the total disappearance of the solvent, if there was any, it being argued that nothing but heat could have escaped from the cavities.

It is farther maintained, that as the metals generally appear in veins in the form of sulphurets, the combination to which their composition is owing could only have taken place by the action of heat, and, further, that metals being also found native, to suppose that they could have even precipitated pure and uncombined from any menstruum, is to trespass against all analogy, and to maintain a physical impossibility.

It is therefore inferred that the materials which fill the mineral veins were melted by heat and forcibly injected in that state into the clefts and fissures of the strata.

The fissures must have arisen, not merely from the shrinking of the strata while they acquired hardness and .solidity, but from the violence done to them when they were heaved up and elevated in the manner which the theory has laid down. Slips or heaves of veins, and of the strata inclosing them, are to be explained from the same violence which has been exerted.

The parallel coats lining the walls or sides of the vein, which are attributed by Werner and others to aqueous deposition, are ascribed to successive injections of melted matter.

Again, it is said that if veins were filled from above and by water, the materials ought to be disposed in horizontal layers across the vein." (Rep. Brit. Assoc. Adv. Sci , 1833, page 10. Taken from Prof. Playfair's " Illustrations of the Huttonian Theory of the Earth." ) Hutton's theory grew in favor with miners and geologists for many years, and about 1820 many were so extremely imbued with the igneous theory that veins of quartz and porphyry as well as beds of quartzyte and limestone or marble were regarded as of eruptive origin.

On the supposition then generally held that all. ore deposits were of the nature of veins or lodes connected by fissures with deeper portions of the earth, and with an imperfect knowledge of chemical affinities and of the change that takes place when iron and quartz are fused together, it is not to be wondered at that

Ibon Ores Of Minnesota. 219

deposits of iron ore and jasper were considered to be oat-pourings of molten matter from the interior of the earth. Bat that this idea should have survived for nearly a century in spite of the light thrown upon the subject by practical mining and by experimental chemistry, and that it should even now be maintained by eminent geologists, is surprising to say the least, and is a good illustration of the difficulty of eradicating an erroneous idea when once it has obtained credence and acceptance in the human mind.

The theories of Gerhard, Lasius and Delias have generally been considered as containing the idea of lateral secretion or of segrega- tion. This theory was elaborated by G. Bischof, who only applied it to true veins and not to all varieties of ore-deposits, as was origi- nally the case.

It is thus seen that prior to the beginning of this century the four principal theories of the origin of ore bodies in general were: 1. That they were formed contemporaneously with the rocks which enclose them. 2. That they were open fissures filled by precipitation from above. 3. That they were cracks formed by upheavals and filled with injected molten matter. 4. That they were formed by lateral secretion: i. e., by deposition from waters, which percolated through the adjoining rocks and dissolved certain ingredients from them which they again deposited in the fissures.

Geologists, however, were not evenly divided in opinion among these four views. The theory of contemporaneous formation was generally discarded as early as the 16th century. Stahl is the only decided advocate of it since the beginning of the 17th century, and he maintained it only because he found so many objections to the other theories which he did not know how to explain. Among uneducated miners, however, it was and is still a common opinion. De La Beohe in his Geology of Cornwall, (1839) says: ''With a few important exceptions, the present impression among the Cor- nish miners seems to be that lodes are contemporaneous with the rocks in which they are found. How long this impression may have been prevalent it is difficult to ascertain; Pryce, who published his Mineralogia Cornubiensia in 1778, makes no mention of this opinion, which, as he often cites those of his day on other subjects of the same kind, we may have expected him to have done if it prevailed to any considerable extent at his time in Cornwall." (p. 863.)

Werner's theory was satisfactory to the common mind and the. casual observer for 25 or 30 years; but careful students had already discarded it as early as 1825, and in 1840 Baron Beust completely overturned it.

220 Bulletin No. Vi.

Hutton's theory of injection was the idea which took the strong- est hold and was believed, with some few modifications, by the ma- jority of geologists up to the middle of the present century. Von Cotta says: "When' the igneous origin of many rocks, which oc- cur as dikes, had once been recognized, many persons were inclined to consider all lodes as igneous-fluid injections. Petzhold, in his geology ( 1840) even attempted to maintain that as being the most recent and consequently deepest ramifications from the interior of the earth, they must necessarily be the richest in metals and have the greatest specific gravity."

In 1833 John Taylor presented a report to the British Associa- tion for the Advancement of Science upon ''The present state of knowledge respecting mineral veins." After reviewing and sum- marizing the various theories advanced to account for their origin, he suggests that the chief difficulty with all theories up to that time was that each theory had been drawn from a limited series of ob- servations on only one or two of the many kinds of veins, and was then supposed by their originator to apply to all mineral lodes. He thinks that no general explanation can be accepted for all ore- bodies, but that each one of the early theories may have some truth in it and may apply to one or more classes of deposits.

When this idea was fully accepted a long step forward was taken toward the right understanding of ore-bodies, and* we may begin from that time to look for accurate observations and reasonable theories as to the origin of iron ore deposits, whether in beds or veins. Still, though iron ore deposits were now understood to occur in beds and irregular accumulations differing in many respects from fissure veins of gold or silver or other ores, it was yet some time be- fore it was realized that different kinds of iron ore deposits may have had different origins. Consequently if one observer proved to his own satisfaction that a certain deposit of iron ore was asso- ciated with eruptive labradorite rocks and could not be separated genetically from them, he jumped immediately to the conclusion that all other accumulations of iron ore were of igneous origin; or if another observed bog iron ores in process of formation, and after great study arrived at a correct understanding of the chemi- oal reactions between the decaying organic matter, the atmosphere, and the iron compounds, he was at once blind to any other method of the formation and accumulation of iron oxides and must put .himself on record as concluding that "both novo and always iron ore is and has been accumulated by organic agency."

Hence we may now turn our attention exclusively to the various theories of the origin of iron ore proper. References are made in

Iron Ores Of Minnesota. 221

the accompanying bibliography to papers and books in which this subject is touched upon, and where reference is not made here to the places where a certain idea is to be found, such data and often a literal quotation or a resam£ of the opinions of the author re- ferred to may be found in the bibliography.

Many different opinions have been and are still held by geolo- gists as to the forces which have co-operated to produce deposits of iron oxide, and as to the manner in which these forces have been applied to the compounds which have been made to yield up their store of iron. In fact there have been generally two or three theories for each of the workable deposits of ore, so that a student is at a loss to know what to believe concerning the origin of any one of them.

Bog Iron Ores.

There is one class of iron ores, however, upon which geologists practically agree. That is the ore which can be observed to be in process of formation in our marshes, viz., bog ore or limonite. No one would claim an eruptive origin for such ores, because they can observe their deposition from day to day. These ores, although generally somewhat impure, are essentially hydrated peroxide of iron (Fe,08+3HaO), containing when pure, 14.42 per cent, of water and 59.9 per cent of iron. Phosphoric acid is frequently present in deleterious amount.

The general explanation given of the way in which they are are formed is as follows:

Peroxide of iron (ferric oxide or hematite) is found in fine parti- cles in all streams, lakes, ponds and marshes. It is derived from the decomposition of rooks in which iron occurs in any combination whatever; upon the decay of these rocks the atmosphere attacks the iron, and, in the absence of reducing agents, burns or oxidizes it just as any piece of metallic iron, a hammer or saw, for example, exposed for any length of time to the damp air, is oxidized, forming iron rust or ferric oxide. This iron rust, however, is dissemina- ted through the rocks and soil in fine particles, and being insoluble in the ferric condition, would remain there but for the action of decaying organic matter, which is found in nearly all superficial percolating waters. When vegetable matter decays it undergoes a process of oxidation or combustion similar to that of the rusting iron; that is, the carbon of which the vegetable matter is composed, unites with oxygen and forms carbonic acid gas. Some part of the oxygen required in this process of decay is taken from the djaoent ferric oxide, which is thus reduced to the condition of pro-

222 Bulletin No. Vi.

toxide or ferrous oxide of iron. This ie soluble in waters con- taining any carbonic acid, and thus may be carried off in solution as ferrous carbonate. Upon exposure to the oxygen of the atmosphere, however, or on evaporation, the iron gives up its carbonic acid and again forms ferric oxide. This latter process takes place in the red scum or film which forms on the surface of marshes or ponds filled with vegetable matter, and which occasionally breaks and settles to the bottom. In this way all the iron brought into the marsh in a state of solution may be precipitated in a bed at the bottom.

If there is an excess of decaying vegetable matter at the bottom, of the marsh and the iron is still in such abundance that it cannot all *be taken into solution it is accumulated in the form of ferrous carbonate, which is the ore so common in connection with the Coal Measures.

On this point Bischof says in his Chemical and Physical Geology, vol. 1, p. 170: ''It is evident that the formation of this ore of iron, must have taken place during all the earlier sedimentary periods since the appearance of vegetation upon the earth."

Carbonic acid is not the only acid produced by decaying vegeta- ble substances which thus aids in the accumulation of iron ore deposits. Crenic acid, apocrenic and humio acids all give com- pounds of peroxides of iron which are easily rendered soluble with the aid of the ammonia produced by the same decomposition! of vegetable matter. These acids undoubtedly play a larger part in the accumulation of bog ores than they have usually been, credited with.

A quotation from Dr. J. 8. Newberry may make this process clearer. After explaining how the iron is brought into solution by the aid of carbonic acid he continues: "Having now got the insol- uble peroxide of iron into a soluble form, let us follow it in its travels. All the drainage of a forest-covered country may be as- serted to contain iron. Where the rocks and soils hold this metal in unusual quantities the amount dissolved and transported is pro- portionately great, and many of the springs are chalybeate. Wherever these solutions of the salts of iron are exposed to the air they absorb oxygen, and the iron is converted into the hydrated sesqui-oxide. This we see in the precipitate of iron springs as yellow ochre; in bogs and pools it forms an iridescent film, which, when broken, sinks to the bottom of the water. If it there finds decaying organic matter, it is robbed of a portion of its oxygen, which unites with the carbon to form carbonic acid, and this bubbling to the surface escapes. The iron thus becoming again a

Iron Ores Of Minnesota. 223

soluble proto-salt, and floating off, absorbs more oxygen, and carries this also to the organic matter, continuing to do this until all is oxidized; then it is precipitated as limonite or bog iron ore. Thus it will be seen that, under such circumstances iron plays the same part that it does in the circulation of te blood, where it is oxid- ized in the langs and carbonized in the capillaries, serving simply as a carrier of oxygen."

Prof. J. A. Phillips in his "Treatise on Ore Deposits" p. 26, says: "There can be but little doubt that the majority of these stratified deposits of crystalline iron ores were originally thrown down in a hydrated form from aqueous solutions; but haying been subsequently exposed to metamorphic influences, they have not only lost their combined water, but, like the rocks enclosing them, have become crystalline. It is probable that in some instances, they may have been deposited as carbonate of iron, which first lost its carbonic acid and subsequently became more highly oxidized."

One other method of the formation of deposits of bog iron ore was explained by Ehrenberg, a German microsoopist, in 1836. He suggested .that they are produced by minute infusoria whose cells consist mainly of hydrated oxide of iron. Of these the Oaillonella* ferruginea is a notable example. It secretes iron oxide from dilute solutions and being found in many marshes and peat bogs it may play quite an important part in the accumulation of bog ores.

Lake ores are probably formed in a manner analogous to the bog ores. They are found in the Scandinavian lakes, and furnish considerable ore for the manufacture of cast iron. The deposits are found in the lakes at a distance of about thirty-five feet from the shore, and form a stratum averaging about a foot in thickness. Such a stratum when once removed is renewed in twenty or thirty years. The ore contains but a small per cent of iron, and is mixed with various impurities such as oxide of manganese, silica, alu- mina, lime, sulphuric and phosphoric acids. The structure of the ore is generally o&litic. Hausmann suggested that the iron in moat of these deposits originated from decomposed iron pyrites in greenstones, and that many lake ores have been formed by the erosion and redeposition of neighboring bog ore deposits.

Crystalline Iron Ores.

A casual perusal of the accompanying bibliography will show the great variety of opinions held by different writers as to the origin of these ores. We shall glance at the various theories that have been proposed, and perhaps present some of the objections arged to them by others.

Tkli word Is sometimes written GaUUmeUa.

224 Bulletin No. Vi.

Classification of Theories. Prof. A. A. Julieu in the Proceed- ings of the Academy of Natural Sciences of Philadelphia for 1882, has given a synopsis of the various views on the origin of crystal- line iron ores. He divides them first into "two classes, as they may refer the iron ores, enclosed in the subterranean strata, to an extraneous or to an indigenous origin."

A. Theories Of Extraneous Origin.

1. Meteoric Fall.

2. Eruption as dykes, (or in masses accompanying basaltic flows.)*

3. Sublimation into fissures (or porous rocks.)

B. Theories Of Indigenous Origin.

4 Concentration from ferriferous rooks or lean ores, by the sol- ution and removal of the (other) predominant constituents.

5. Saturation of porous strata by infiltrating solutions of iron oxide.

6. Infiltration into subterranean chambers and channels.

7. Decomposition of pyrite and other ferruginous minerals, en- closed in decaying schists, and transfer of the iron oxide in solution as ferrous sulphate.

8. Derivation from original deep sea deposits of hydrous ferric oxide, or of ferrous carbonate (deposited either by chemical pre- cipitation or by mechanical sedimentation.)*

9. Deposit from springs.

10. Alteration of diffused ferric oxide into ferrous carbonate.

11. Metamorphism of ancient bog ores.

12. Metamorphism of ancient lake-deposits.

13. Violent abrasion and transport.

14 Concentration and metamorphism of iron sands. To these fourteen divisions of Julien's may be added four more, namely:

15. True veins, formed by segregation or chemical secretion.

16. Electro-telluric action, i. e., as a result of the reactions and decompositions produced by electro-magnetic currents in the earth.

17. Substitution of ferrous oxide for lime in the original rock, and change to peroxide.

18. Secondary product from the decomposition of basic rocks, eruptive or metamorphic; and concentration of the oxide of iron in drainage basins.

In the accompanying bibliography will be found quite full quo- tations from Prof. Julien's paper. We shall make frequent refer-

*For completeness we have added the portions in parenthesis.

Iron Ores Of Minnesota. 226

ences to it here and use it as the basis of our remarks, as it is the most complete and concise in its classification and discussion of the various theories of the genesis of crystalline iron oree. At the close of the chapter will be found a table which shows the sup- porters of the various theories and the dates of their advocacy of them.

Discussion of Theories. Our first theory is that of Meteoric Fall. This theory of the origin of a deposit of iron ore was ad- vanced by C. J. B. Karsten in 1853. He supposed that the deposit of iron ore near Thorn in central Europe might have fallen from the sky, and described it as having a half melted appearance un- like that of most deposits of iron ore. There were at least 1,000 tons of iron in this deposit which covered about 700 acres of ground within four inches of the surface. The magnetic iron ore was intimately mixed with an olivine mineral and in this respect resembled some of the Minnesota ores.

Prof. Julien mentions the iron mountain of Gerro de Mercado, in Mexico as another which was described as of cosmic origin, and says that "such a view is sufficiently controverted by the minera- logioal constitution of the mass, and its structure— 'immense veins of specular iron ore standing nearly vertical.' "

In this connection may be noticed one or two of the observed occurrences of metallic iron in various portions of the world. In the Annual of Scientific Discovery for 1856 it is said that the Rev. Mr. Adamson reported meteoric iron to be abundant in South Africa; Pallas was said to have found it in Siberia in 1776, and others in South America, New Mexico and other regions.

In most text books on mineralogy and geology it is stated that native iron is only a curiosity and is not found except in meteoric ' masses. A section of such a mass of meteoric iron is shown on plate XL.

In 1870 A. E. Nordenski&ld discovered some large masses of native iron mixed more or less with olivine and other basaltic con- stituents on the island of Disco off the coast of Greenland. Native iron had been reported to exist there, and implements of wrought iron had been obtained from the natives, but the source of the iron they refused to disclose up to the time of Nordenskittld's visit.

These masses of iron were several tons in weight, and as they contained nickel and displayed Widmanstattian figures Norden- skiOld believed them to be of meteoric origin; and finding them to be bedded in the basalt he came to the conclusion that an immense meteorite fell into the basalt when it was still molten and flowing.

226 .Bulletin No. Vi.

Prof. G. Tschermak also advocated the oelestial origin of this iron; but it has now come to be generally considered to b9 of ter- restrial origin, as we shall see later.

2. Eruption as dykes, or accompanying basaltic flows. This view, as we have seen, was first proposed in detail by Hutton in 1795, and has had more numerous supporters than any other theory, but they were chiefly geologists of the first half of the century who advo- cated also the eruptive origin of quartz veins, limestone beds and even beds of quartzyte, or who limited the igneous ores to certain magnetites and to native metallic iron, associated with basic erup- tive or metainorphic rocks. The geologists who have during the last thirty years, persistently maintained the eruptive origin of those iron ores which are intimately associated with highly acidic, or sili- ceous rocks, are very few indeed.

The idea held by the supporters of this theory is that there is a large body of iron situated at a great depth from the surface, and that on account of pressure and the resulting disturbances, cracks have been produced in the crust of the earth, which fissures or cracks have been filled and overflowed by the molten iron from below, either as metallic iron or magnetic oxide of iron mixed with basalt.

W. W. Mather, in 1839, speaks of " injected veins " of iron ore penetrating the gneiss and crystalline schists of New York. These veins he considers to have melted the gneiss in some instances, but still to have maintained an abrupt contact with it instead of flowing together. He also thinks that the veins lead downward and are connected with the main mass below.

Sir R. Murchison satisfied himself that certain magnetites in the Ural mountains were not metamorphosed portions of sedimen- tary strata, but that they had flowed out of the adjacent hillside into the depressions they now occupy.

Foster and Whitney have frequently been quoted as the authors and advocates of this theory. In 1851 they advanced the idea that the iron ore deposits of lake Superior had been erupted in the bed of the ocean partly or wholly in the metallic state, and were subse- quently rearranged by oceanic action and covered by succeeding sediments.

Dr. Ebenezer Emmons was an ardent advocate of the igneous origin of iron ores, as well as of quartz and caloite veins and beds of limestone.

Mr. H. D. Rogers recognized other modes of origin for some iron ores, but said in 1858 that " magnetic iron ore occurs only in the form of true veins of injection or genuine mineral lodes." Some-

Iron Ores Of Minnesota. 22/

times the ore has been " injected " into gneiss and again into sand- stone.

B. Yon Cotta, in 1864, accepted the eruptive hypothesis for many deposits of iron ore, magnetite, hematite, and even the carbonate of iron.

The magnetic ore of iron is the one most generally considered to be eruptive, as it is found in conjunction with basic eruptive rocks and in volcanic flows. It is quite an anomaly for any recent writer to express the opinion that various ores, both magnetite and hematite, where they are found associated so intimately with car- bonate of lime and with quartz as to be inseparable from these minerals, genetically, are of igneous origin.

This anomaly is presented to us in two instances. In his Acadian Geology, 1878, J. W. Dawson describes a vein of iron ore associated with carbonates of lime and magnesia which he tells us is a good example of a vein filled by molten, or even sublimed carbonates of lime, magnesia and iron. This vein, he says, was subsequently partially roasted by heat "so as to produce the red ores, which are obviously the result of the heating and oxidation of a part of the carbonate of iron, and this process may be seen, on minutely examining the vein, to have extended itself from the walls of the smallest fissures."

This is a good illustration of the disregard of chemistry on which are based some of the early theories of the origin of iron ore de- posits. To take notice of all the impossible and illogical arguments would be a tedious and useless task. The mere mention of them is sometimes enough to excite laughter. To say nothing of the impossibility of retaiuing the carbonic acid in the carbonates when they were subjected to such great heat as to melt and even sublime,* one cannot help wondering why subsequent

On the volatilization of metals and metalliferous minerals and their redeposition In mineral lodes Pros. T. O. Chamberlin has written the following (Geol. Wis. 1873-70, toL It. p. 883); "The volatilization of the whole group of minerals presents great diffi- culties. The galena, to which attention is too apt to be confined, may be vaporized, without decomposition— at least can be volatilized and rocondcnsed as galena— and the same may seemingly be accomplished in the case of pyrite and blende, but not of oaldte. It Is a familiar fact that, at a very moderate temperature, calcite (limestone) decomposes to caustic quicklime and that, thou, not even the oxy-hydro#en blow- pipe Is able to fuse, much less volatilize, in appreciable quantity, and to this property tt owes its utility in the calcium light. To suppose that calcite is a product of sub- limation Is to severely tax credulity without the sanction of the slightest evidence. To the unlnstructed objection that calcite is not an ore.lt may manifestly be replied that It Is as truly a metallic carbonate as smlthsonite, and that it is only this immeasur- tile resistance to the decomposing ofTocts of heat, that prevents Its more frequent pad notion to the metallic state, and possible use as a metal for cortaln purposes.

The relations of thooresln the lode are such as to require their deposition at the time. In many cases, and they must, therefore, have been supplied simultane- and maintained in coexistence, till deposited.

228 Bulletin No. Vi.

roasting would oxidize the carbonates, and particularly the iron, if the original melting failed to do so; and we are further sur- prised to learn that the subterranean heating of spathic iron (fer- rous carbonate) produces red hematite (ferric oxide). Here is a remarkable instance of oxidation in the presence of reducing agents. Other inconsistencies of chemistry and physical structure will be noticed in the description of this "vein," which is quoted in the appended bibliography..

A still more remarkable instance of this kind of geological in- difference to chemical laws and reactions is found in the argu- ments of Dr. M. E. Wadsworth to prove the eruptive origin of the iron ores and jaspers of the lake Superior region. These argu- ments have been made very strong and have carried considerable weight as well from the high authority from which they emanated as for the ingenuity and assiduity with which he maintained his position, and the difficulty of advancing any other satisfactory theory owing to the complexity of the phenomena presented in this region. But, however plausible Dr. Wadsworth's arguments may be on general grounds, and however difficult it may be to explain all the observed facts in any other way, we believe that the simple fact that granular quartz occurs in a state of almost chemical purity inseparably mingled with the oxide of iron in a similar state of purity is sufficient in itself to overthrow the idea that they were erupted together in a molten condition, f

For the sake of those who are not familiar with Dr. Wadsworth's theory we will give the main points of his argument and mention some objections to them.

This is a very bard thing to believe, since there are such wide differences between their temperatures of vaporization and condensation. .

It is easy enough to form a vague, general conception of the vaporization of metallic substances by the mysterious power of the unknown interior of the earth, but to form a precise, detailed view of just how galena, blende, pyrite and calclte, or the elements from which they were formed, volatilized simultaneously in the face of the fact that their temperatures of volatilization are immensely separated, presents Herculean dif- ficulties, but these are dwarfed to Lilliputian dimensions in comparison with those encountered in attempting to imagine precisely how these several substances could have been condensed so as to form, within the space of a hand specimen, a group of regular, large-faced crystals that grew up together. A temperature that would admit of the deposition of one would be quite incompatible with the formation of another."

tin " Lesley's Iron Manufacturers' Guide " are a few quotations (p. 3to) from Bischof bearing on this point. From the example of iron welders who sprinkle sand on the end of the iron in order to convert the coating of magnetic oxide into silicate which peels off at every blow he says: " See then from these examples how impossible it would be to find quartz and magnetic iron separate if they were of igneous origin." And again after mentioning the quartz crystals in magnetic ore In various mines, he says: ''Should the ultra-plutonlsts grant that the accompanying quartz is of watery origin but still claim an igneous origin for the magnetic iron, they will find no escape this way, for the welding trick must be repeated on a grander scale in a supposed molten ore vein enveloping quartz, forming a silicate slag."

Iron Ores Of Minnesota. 229

Dr. Wadsworth's views may be stated as follows: The jasper, -which he has named jaspily te, is acknowledged on every hand to be an inseparable part of the iron ore. The origin of one gives the origin of the other. They grade into each other and their inter- dependence is such that the relations of one to the country rock give the relations of the other.

The jasper and ore sometimes form what appear to be "dikes" -which jut out from the main mass across the strike of the schistu -which constitute the country rock.

The schists are frequently hardened and discolored, or, as Dr. Wadsworth says, "baked" at the contact with these so-called "dikes" of jasper and ore.

The deposits of ore and jasper are lenticular, and masses of schist enclosed between various branches of the deposit are wedge- shaped, as if the ore was erupted from below, and surrounded the schist thus.

The banding of the ore and jasper is compared to the striped fluidal structure of rhyolytes and f elsytes.

Some of the iron ore in Michigan being found to be in octahe- drons, Dr. Wadsworth thinks is an indication that it was all magnet- ite originally and has been since changed to hematite by oxidation.

Crystals of hematite crystallizing from the molten magma of trachytes and rhyolytes have long been known, and are described in all the standard work? on*micro-lithology.

The jaspilyte and iron ore are sometimes cut up by cross-joints which give an apparent basaltic structure to the whole, making it resemble a dyke.

The uniformly fine grains of quartz which constitute the jaspi- lyte masses have been supposed to be the re3ult of incipient disin- tegration of these very old deposits which are supposed to have been originally in the state of vitreous and glassy flows of acidic material. And the fact that the grains are unlike mechanically worn and chemically deposited quartz grains lends some strength to this position.

The above are the main points of Dr. Wadsworth's argument, and are mainly an elaboration of the views of Prof. J. D. Whit- ney, published in 1851. It is not strange that a pupil and a sub- sequent co-worker should have imbibed the same opinions held by Prof. Whitney for so many years.

Bat there are a great many objections to their theory, — objec- tions which appear to us sufficient to convince any one, who thoroughly examines them and appreciates their force an<l applica- tion to the subject, of their validity ami truth. A number of these

230 Bulletin No. Vi.

were given in the Fifteenth Annual Report of the Geological Sur- vey of Minnesota, (1886) and will be repeated here.

1st The iuter-banding of the jaspilyte (hematite, jasper of various colors, white silica) is exactly that which is seen in sedi- mentary rocks. The different bands fade into each other across the structure by faint transitional stages. They maintain over long distances a parallel striping such as sedimentary thin laminae do in all fine-grained rocks and clays, but when followed far enough they are seen to taper to points and disappear as their neighbors in- crease. In its hardened and apparently carbonaceous state this rock appears rigidly slaty, though still mainly siliceous, and stands on edge much like an argillyte. This slatiness is visible in some places where the tortuosity incident to folding and crushing has not been developed. It is straight and distinct, and is in conse- quence of the weathering out of some of the softer thin laminae. It is found north of Tower, near the towu, forming some of the conspicuous knobs facing toward the south. These slates are not black, but they are dark colored and remind the observer of some of the black slates of the Animike rocks farther east, and were it not for their perpendicular position, and their other relations to the surrounding rock-masses they could be considered their equiv- alent. This slaty structure is due to a weathered condition of dif- ferently constituted bedded materials, and differs from the slaty structure that may be developed in igneous rocks due to their fluidal structure, in that it is straight and rigid instead of undula- tory or wavv. Rock No. 893.

2d. The jaspilyte, though frequently, and perhaps most fre- quently, presenting a sudden and definite transition to the schists, showing a possible igneous origin of one or the other, does not al- ways do so. It is found passing by a series of short alternations into a schist, which, though greenish and easily confounded with the unconformable green schist, is a constituent part of the jaspi- lyte, or at least of the formation in which the jaspilyte exists. Thi structure and transition is represented by rock 894. It is here ac- companied by much pyrite. This is obtained near the Ely mine, where the railroad cuts the formation. In this schist, thus alter- nating with jaspilyte, there is no sign of the "baking," so called, that is assigned to the red-colored schist at the mines, and the infer- ence is natural and inevitable that the jaspilyte, here seen to be the contact rock on the schist, did not produce the effect of igneous dikes, and that this is the original condition of the mutual co-rela- tions of these rocks.

Iron Ores Of Minnesota. 231

This interbedding of schist and quartzyte, the latter being some- what purple, extends along the railroad as far east at least as to the Stone mine, where it is again well exposed (rock 919). Here the jaspilyte passes by gradations into the green schist. In the imme- diate vicinity are jasper nodules indigenous in the midst of the schist, red and purple, some of them five or ten feet long, appear- ing like quartzose aggregations in the midst of their native sedi- ments. Toward the south, at some little distance from the point at which this interbedding is visible, the siliceous grains are white, instead of purple, disposed in thin sheets.

At the West Ely mine the open pit shows, on the east wall, a succession of jaspilyte and schist in beds somewhat like those sketched in figure 1, page 48.

Here we notice "wedge-shaped"masses of jaspilyte surrounded by schist, which is just the converse of the cases reported by Dr. Wadswortb, and which indicated the eruptive origin of the ore. Here the same wedge-shaped masses would indicate that the schist is eruptive around and through the jaspilyte. But the schist, be- sides grading off into graywacke and slate with an evident sedi- mentary banding, is found to contain rounded pebbles pf vitreous quartz which prove its aqueous deposition — subsequent to its erup- tion. So that part of the evidence goes for naught

At the East Ely mine, next adjoining on the east, the same bed- ded alternation of schist and jaspilyte is apparent, but owing to the greater development it is brought out more distinctly. Figure 2 on page 48 of this bulletin represents the east face of this mine, the observer looking on the edges of the beds. Each one of these beds of jaspilyte has a fine internal lamination which is much contorted. The schists, which are pervaded by a schistose struc- ture when not reddened by iron, and which when reddened are less schistose, and "baked," though soft, do not manifest, so distinctly, a finer internal lamination. The four-inch bed of schist at the left of the sketch runs the whole length of the mine, and even appears on the stripped surface of the opened pit, running 600 or 600 feet altogether.

At the Stuntz mine the same regular (or irregular) alternation of beds of ore with red shale can be seen, there being visible three schist beds, from six to ten feet thick, dipping N. or N. N. W., about 80°.

In the foregoing tables of diamond drill borings on pages 37-36, the continual alternation of schist, jaspilyte and ore is a very plain and persistent feature, and is in itself strong proof that neither the jaspilyte nor the schist could have been erupted in

232 Bulletin No. Vi.

its present position, for in order that this regular alternation should be so uniform and general and should extend thus for miles, re- quires some cause which could open the crust of the earth in per- pendicular sheets and inject equally thin alternating sheets of igne- ous matter. It is much more like the alternation of sedimenta- tion, followed by upheaval and pressure.

3d. The schists are not by any means usually baked alongside of these jaspilyte belts and masses. This is shown by rock sample No. 894, and also by many other illustrations from other points that could be adduced. Bock No. 895 shows a gradual transition between the schists and the jaspilyte, without pyrite, near the same place as No. 894, not from between two jasper belts, but more dis- tant, rather from the general mass of the schist. The contact is most commonly a simple one, with an abrupt transition, or there is a gradual interchange without any appearance of the so- called bak- ing. This gradual transition is most apparent, and most frequent, in other places than along the great jasper belts.

The green schists themselves, at the same railroad cut, seem to become homogeneously arenaceous with the same (rounded?) gran- ular quartz as seen in the jaspilyte — which, if true, (and subsequent observation in this and other localities has proven it absolutely) seems to require some other explanation besides the theory of incipient disintegration to explain the granular condition of the quartz in the jaspilyte. The theory that the rounded grains were thrown down as a sediment would then be extended rightly over both kinds of rock.

4tb. In the enclosing green schists there are what appear to be not only pebbles, but lenticular masses of jaspilyte, or at least of jaspery and chalcedonic quartzyte. These are granular like all the rest, and easily distinguishable from the secondary or chemi- cally deposited silica. Some are as fine as a pin- head, and do not show much, if any, disturbing effect on the fine laminae of the schistose structure, and others are somewhat larger, and larger, and larger, and produce some warping of the laminae, the warping extending further and further from their surfaces as their size increases. These minute pieces of jaspilyte are of the same char- acter as the larger masses, and must have had the same origin. But they are so numerous that thousands may be embraced in the area of a square foot They are sometimes distributed amongst the schist rather uniformly, and sometimes they are crowded about some of the larger masses. There is also a coarse breccia, with small and large, rounded and angular pieces of the jaspilyte, all embraced in a sparse matrix of green schist, resembling somewhat

Iron Ores Of Minnesota. 233

a conglomerate. The inference is natural, and inevitable, that these jaspilyte pieces could not have been introduced as eruptive matter in the green schists, but must have been coincident in time with the advent of the schist. Their original, first formation and their source, would still be a matter of further investigation. ( Nos. 889, 897.) Compare figures 3, 4 and 5, and plate in of this bulle- tin.

5th. The hematite can be seen in some places, where favor- able circumstances have conspired to preserve the structural rela- tions, to acquire the finely bedded or laminated or banded structure seen in the coarser bands of the jaspilyte. This is particularly visible where the hematite is specular — indeed the specular structure is due to the cleavage off of large surfaces of the ore along these lamination planes. Id other places this fine strip- ing is seen to fade out 'both longitudinally and transversely into a massive, hard hematite. This does not show, perhaps, that this banding is not a fluidal structure due to the eruptive nature of the rook, but it shows exactly the structure that would be expected in the rock if it were all of sedimentary origin — at least the jaspilyte — and it seems to indicate that the iron-ingredient is of the same origin and date as the siliceous ingredient and not of later date. It partially obliterates the characteristic fine lamination of the jaspilyte.*

6th. There are places, not common, where the iron ore seems to be a breccia of jaspilyte and "baked clay," or, more likely, a highly ferruginated and hardened clay. Generally they are better ores when associated with the large' jaspilyte belts, and poor when in small particles. These breccias are supposed to form a constituent part of the iron-bearing strata, and should not be confounded with those conglomerates made up by the mingling of transported masses of jaspilyte in the enclosing green schists. This fer- ruginization of fragments of both jasper and clay, in a breccia, teems to show that the iron, as an ore, is not necessarily a part of the jaspilyte, and this idea is strengthened by the fact that the ore of the Gogebic range is one that consists largely of a breccia of some soft rook. If then the hematite be not essential to the rock known as jaspilyte, the residue would be almost entirely silica, and it is a novelty to suppose that pure silica could ever have been injected among the rocks of the earth in the form of igneous dikes. If, on the other hand, we believe, as we do now, that the iron and silica

*Itls probably because tbe Iron ore has boon subjected to pressure and heat that the lamination is obscured or erased, and not because of any difference In date or Banner of origin. When It does not totally obliterate It, It accommodates Itself to teat structure. Bock 006.

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were deposited together, and the hematite does constitute an essential part of the jaspilyte, the novelty of supposing it injected is three-fold what it was before: 1. The injection of molten silica; 2. The injection of molten hematite; 3. Their uncombined state chemically, and the distinctness with which each stratum or ribbon preserves its outlines without having flowed together with those on either side.

7th. When this silica, which has been styled chalcedonic, in- terleaved with the hematite and jasper, is weathered, and finally disintegrates, it crumbles into a fine white sand, the grains being of uniform size. It is then friable like the St. Peter sandstone, and could be used for scouring and polishing. If a large piece of such weathered "chalcedonic" silica, carefully selected, be thrown down on the face of the firm jaspilyte, it is crushed with a dull ex- plosive noise, the individual grains of silica flying from the point of impact in all directions, the phenomena being the same as when a slab of soft sandrock is thus thrown down on a hard surface. On the contrary, when a piece of the chemically deposited silica, taken from some of the veins with which the country rock is every- where intersected, is thus treated, howmuchsoever it may be weath- ered, it is either splintered into sharply angular bits of various sizes, or is simply crushed into white powder on some of its cor- ners. In this the white "chalcedonic" silica behaves like the quartzytes at Pipestone and New Ulm. They are also sometimes vitrified superficially and very hard, with the appearance, includ- ing the color, of much of the fine quartzyte seen in the jaspilyte but when disintegrated by the atmosphere they dissolve into a homogeneous white sand. Bocks 869, 899, 900.

8th. It is apparent at many places about the Vermilion mines that the great mass of the iron formation (the jaspilyte) is con- formable with the schistose structure of the schists that inclose it. It is absolutely conformable with the schists that are, at some points, a little removed from the mines, interstratified with it; and, in a general way, it is conformable with the structure of all the sur- rounding schists. On the supposition that the jaspilyte be igneous these schists also would have to be considered sedimentary, and this schistosity would have to be taken for the sedimentary struct- ure,* the unconformities, wherever they exist, being due to the fracture of the beds, and the introduction of the fluid jaspilytes. Now in order that such a conformability should exist at the time of the accumulation of the sediments on any hypothesis, the jaspilyte

Dr. Wadsworth seems to have so considered it in his paper on the Marquette ores; without, however, vouching for its correctness.

Iron Ores Of Minnesota. 235

mast have been introduced at the time of such accumulation and while the sediments were yet soft; and that, on the igneous theory, would not account for the angles and arms and "dikes" that Dr. "Wadsworth has illustrated at Marquette, running across the sedi- mentary structure of the schists; and would require that there should be, besides, a marked difference even now, in the upper and lower surfaces of such inflowing igneous strata, such as we do not

9th. If the jaspilyte be supposed to have made its advent after the sediments were hardened there is no other way but to resort to the igneous theory, and then we have many difficulties, viz.:

(a) Why should it appear always at the same, or nearly the same, geological horizon ? No other admittedly eruptrVe rock does that

(b) Why should it run substantially conformable to the strati- fication in all the important localities ? No other admittedly eruptive rock does that.

(c.) Why should the bulk of the whole be a granular silica ? There is no other such igneous rock known. If it be said that the granular condition of the silica be due to incipient disintegra- tion, why does the same granular condition prevail at the depth of seventy- five or more feet (nay, 875 as found in diamond-drill cores) below the surface, as found in the Vermilion mines?

(A ) How could the oxides of iron coexist with silica at the temperature needed for fusion without chemical union ? No other instance is known.

{e.) How could the evenly banded, long-drawn out, almost never-blending layers seen in the jaspilyte, consisting of the same elements in endless alternation (hematite, jasper, quartzyte,) be imagined to have been preserved in their tortuous parallelism during such a flow through open fissures ? No other such fluidal structure is known. The real igneous fluidal structure shows a general parallelism in the structural lines, in a nearly homo- geneous rook mass, but the fine bands separate, cross over, blend and mingle in a general flow, at longer or shorter intervals.

(/.) How does it happen that the so-called flow age structure is - not parallel with the surfaces of the rock walls, in cases where the jaspilyte enters arms or bands or jogs off in the fissured schists ? In no case, in the Vermilion mines, has such a parallelism been seen yet; but, either the structure is entirely lost, or it is con- fused by many fractures, or runs at various angles, even to per- pendicularity, to the walls of such a fissure (as at the Stone mine). In other admittedly eruptive rocks the fluidal structure is parallel

236 Bulletin No. Vi.

to the walls of the enclosing rock — at least is parallel to the di- rection of the flow.

The above are the reasons for advocating some other than an eruptive origin of the jaspilyte, based mainly on the observations of the season of 1886, and substantially as given in the fifteenth report. Since then three summers' observations have served to show the general correctness of those views and to produce further arguments against the igneous origin of the jasper and iron ore. These further facts will be found in the seventeenth and eighteenth annual reports, and are summarized in another chapter of this bulletin, combined with some microscopic investigations.

One significant fact is the presence of rounded grains of vitreous quartz Occasionally found in the jasper. These are plainly water- worn pebbles of earlier date than the silica of the jaspilyte. If the jaspilyte were eruptive, and its present granular nature be due to incipient disintegration, the question arises, why have not the still older pebbles contained in it succumbed to the same influences and become finely granular instead of remaining perfectly round and vitreous?

But while it evident that iron oxides could not have been erupted in company with the most acidic kind of material (quartz) and not form chemical combinations with it which would destroy their character and value as iron ores, there may be conditions in which extensive deposits of iron, either as an oxide or in a metallic state, have come in a fused condition from the depths of the earth. In 1852 Prof. T. Andrews, in a paper before the British Association for the Advancement of Science; " succeeded in showing that native iron is by no means an uncommon constituent of basaltic rocks." He found it most abundantly in " a coarse-grained variety of basalt, which forms the hill of Slieve Mish in Antrim." Native iron not meteoric was reported to have been found at various places both before and since this account of Prof. Andrews; but no gen- eral credit was given to these reports until Nordenskittld's discov- eries in Greenland.* The latter masses of iron were very thoroughly analyzed and discussed in Europe, and their terrestrial origin has been finally accepted by such men as Walter Flight, A. Daubr£e, K. J. T. Steenstrup, J. L. Smith, M. E. Wadsworth, J. W. Judd and H. Hensoldt. One of these masses of iron is seen on plate xli. The most of these writers believe that the masses came to the surface in the form of metallic iron. But Steenstrup and Smith think it was reduced to the metallic state by beds of lignite through which the eruption passed on its upward way.

♦Sec L'hancnurtnis and lt'>\\ the Bibliography.

Iron Ores Of Minnesota. 237

However that may be, it is an accepted fact that eruptions of mag- netic iron ore have occurred in connection with basic rock (i. e., with rocks containing less than 55 per cent, of silica); and another of the dogmas of the mineralogical text books will have to be dis- carded, viz: that metallic iron is not found except in meteorites.* In the erupted gabbro of the Mesabi range in Minnesota there is a large amount of magnetic iron ore which occurs in disseminated grains and in large massive deposits. This ore is not exploited at present owing to the lack of demand for ores containing titanium, . which element sometimes constitutes fifteen or twenty per cent of the gabbro iron ore. There is no doubt in our minds that this ore is genetically inseparable from the gabbro, which is on all hands acknowledged to be a true eruptive rock. It also seems likely to us that the presence of titanium in iron ore is always a strong indica- ion of its igneous origin.

3. Sublimation into fissures or porous rocks. This theory for the origin of ore deposits was first proposed by Leh. mann in 1753. It is very closely connected with the foregoing and in many cases has grown out of it Becher (1669) and Eenkel (1725) both supposed ores to be deposited by vapors, but Lehmann was the first to give any clear idea of the real agents supposed to aid in the process. In the early part of this century small deposits of hematite and magnetite were noticed to have been sublimed from the hot vapors issuing from certain active vol- canoes. Ever since then there have been advocates of the forma- tion of large deposits of iron ore in fissures connected with reser- voirs of molten matter in the interior of the earth. It has been supposed by several that these hot vapors penetrated porous beds of rock like sandstones and deposited the red coating of peroxide of iron which surrounds the individual grains. This appears to have been Dr. Emmons* idea, and not that the grains were coated with an infiltrating liquid solution as Prof. Julien says.

It is evident that this theory cannot be applied to deposits of ore in regions that do not show any signs of volcanic action, and the amount deposited from large volcanoes in a great space of time is so small that we can not look for any such immense deposits as we find in various parts of the earth.

Of the three theories of extraneous origin, therefore, we find: (1) That, while masses of iron ore do fall upon the earth, and while there is no known reason why such masses should not be large enough to be worked for their iron, yet no cases are at pres-

Tld. H. 8. Osborne's "Minerals, Mines and Mining," 1884.

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ent known of Bach an occurrence.* (2) That large quantities of iron ore are erupted together with basic rock material from a source deep within the earth and that these deposits may form valuable mines of iron ore* if titanium does not interfere. (3) That no large amounts of iron ore have come from sublimation.

B. Theories Of Indigenous Origin.

4. Concentration from ferriferous rocks or lean ores, by the solution and removal of the other predominant constituents.

Although G. Bischof in 1847 showed that it was quite possible for iron ore deposits to be formed in this way and even went so far as to state that "any mineral may form an iron ore bed" by the process of decay and removal of all but the oxide of iron, it is mainly since 1865 that this method of the formation of limonites and certain other ores has been advocated. It is quite possible that certain non- crystalline ores of iron may have been formed in some such way. But it is rather more natural to suppose that the oxide of iron would be carried away either in solution or in minute solid particles by the same meteoric agents which removed the other constituents of the rocks. Moreover, this process is, as Prof. Julien says, a subaSrial ore, and the ores which might be formed in such a way would have no genetic relation with crystal- line iron ores enclosed in submarine sediments. Prof. Julien fur- ther remarks: "Even were the theory satisfactory in regard to the pure ores, the essential question remains unanswered, viz., the genesis of the original 'ferriferous or lean ores' themselves;" an objection which he apparently did not observe would apply to his own theory, the concentration and metamorphism of iron sands.

5. Saturation of porous strata by infiltrating solutions of iron oxide. This theory was very plainly indicated by L. Yanuxem (1838) in reference to certain ferruginous sandstones of New York. It was adopted by J. M. Safford in 1856 to partly account for some of the Tennessee ores, but he used it in connection with the next theory.

Dr. Adolph Schmidt believed that it would explain to some ex- tent the origin of the Missouri iron ores, and J. P. Kimball applied it to some ores of Cuba.

It is quite evident that although certain porous rocks might be- come very strongly impregnated with iron oxide and even become lean ore, yet no ores could be formed by this means alone which would equal in purity the hematites and magnetites of the crystal- line and older sedimentary rocks.

♦No account is taken here of the probable early Mexican and African use of me- teoric iron-

Iron Ores Of Minnesota. 239

Prof. Julien quotes Dr. Emmons as an advocate of this view, bat a perusal of his writings on the subject will show that it was not his idea that infiltrating waters carried the oxide of iron which cov- ers the grains of sand in the ferruginous sandstone, but that vapors produced by molten rocks in the vicinity permeated the rock and deposited the iron in question. This is also more in accordance with his general notion of plutonic forces.

6. Infiltration into subterranean chambers and channels. This idea is very similar to the last, and may be admitted to account for recent limited and irregular deposits of limonite. But cavities a mile or two in length and from fifty to two hundred feet in width cannot very well have existed in rocks of such composition and structure as those which contain the crystalline iron ores. The physical structure of the latter is another proof that they were not formed by such a process.

This theory has been advocated at least since 1817 and probably much longer.

7. Decomposition of pyrite and other ferruginous minerals, enclosed in decaying schists, and transfer of the iron oxide in solu- tion as ferrous sulphate, to be precipitated as ferrous carbonate or ferric oxide. Prof. G. U. Shepard appears to have been the first to advance this theory of the origin of any iron ores, and as early as 1837. He deserves great credit for his work, and his writ- ings show him to have been far in advance of his time, in the orig- inality and correctness of his ideas. He recognized the fact that the ore deposits of Connecticut which are embraced in the gneiss, are not veins, although they stand in vertical position, but are beds. He considered that the decomposition of the pyrite element of the schists might account for limonite deposits, but did not think the iron was carried away in solution and deposited elsewhere.

Ten years later Bischof showed how decomposing pyrite might produce iron ore deposits; but while we must give him credit for great insight into the chemistry of nature, and must concede pri- ority to him in many things, in this case he was antedated by a pioneer American geologist. This theory has by implication been extended from limonite to the crystalline iron ores, though it is us- ually applied only to the former. "Its connection with the crystal- line iron ores is rendered improbable by the absence of associated limestones (to precipitate the carbonate of iron from the sulphate solution), or, if present, by the lack of evidence of their erosion." This theory will certainly account for the existence of some limon- ite iron-ores, and to this the writers refer those limonites that have been mentioned in several of the Minnesota reports, lying between

240 Bulletin No. Vi.

the Cretaceous and the Paleozoic rocks that are unconformable be- . neath the Cretaceous (as in Blue Earth and Fillmore counties), and which also appear in isolated, generally small, pieces on the tops of the bluffs along the Mississippi river in Goodhue and Wa- basha counties. This ore exists in workable quantity atseveral points in western Wisconsin, and recently has been employed in making iron at the furnace at Black Biver Falls. At numerous places it is in contact with the "Potsdam" sandstone in Wisconsin, and has been described and discussed at length by professors Strong and Chamberlin in volume iv of the report of the Wisconsin survey. There is no evidence, however, that the sulphide, on decomposi- tion, lost the iron by solution and consequent removal. On the contrary the pyrite has plainly simply been oxidized and hydrated in situ.

8. Derivation from original deep sea deposits of hydrous fer- ric oocide, or of ferrous carbonate deposited either by chemical precipitation or by mechanical sedimentation, dehydrated by subse- quent heat, as in the case of hematites, and deoxidized by hydrogen or by further heating, forming magnetites.

This is a very comprehensive theory and might be divided into several which are modifications or variations of it. Different writ- ers have assigned different sets of circumstances to be the causes which induced oceanic deposition of ores. It is probable that there is some truth in all of them, and each particular deposit or class of deposits may have been formed in a manner differing slightly from all others. The conditions surrounding and governing the sediments held in suspension or solution by the ocean's waters must be carefully studied in each case before the exact nature of the deposits can be ascertained. This has not been done in many localities, and as a result the ideas held by advocates of different phases of this theory are often vague and lacking in completeness.

Dr. Edward Hitchcock appears to be the first who advanced this view of the genesis of iron ores, in 1833. In 1861 he repeated and elaborated his earlier conclusions. Too much credit cannot be given to this pioneer in the geological field for his careful state- ments and clear insight into the origin of rocks and minerals, and the nature of the subsequent changes which have affected them.

C. U. Shepard, in 1837, and J. W. Foster, in 1849, found physi- cal marks upon certain beds of iron ore, which indicated that they had a community of origin with the strata which enclose them, but they did not explain in what condition the iron was deposited.

J. D. Whitney in 1855 presented some very thoughtful consider- ations upon iron ore deposits; and he described very truly the sev-

Iron Ores Of Minnesota. 241

eral ways in which iron ore bodies may be produced. But his theories were much better than his application of them to particu- lar cases. He advocated eruptive masses of metallic iron and of magnetic iron ore, and we have seen that there are well established examples of both; but very anomalously, he considered the lake Su- perior hematite ores, which are exploited at present, eruptive, and there are very many reasons why they cannot be. He says of the Pilot Knob iron ores, that "These deposits seem to have been of sedimentary origin, having been originally strata of siliceous sand which has since been metamorphosed. The iron ore may have been introduced either by the sublimation of metalliferous vapors from below during the deposition of the siliceous particles, or by a precipitation from a ferriferous solution, in which the stratified rocks were in process of formation.9' Prof. Whitney came very near announcing an important general truth, and if he had him- self dwelt more upon the idea which we have put into italics we feel sure he would have perceived its applicability to the siliceous hematite ores of the lake Superior basin, particularly as he so well understood the nature of the enclosing Azoic rocks.

Von Cotta also advanced views of the precipitation of iron ores which are quite similar to those of Whitney: "There can be no doubt that all true ore-beds weref originally formed by mechani- cal or chemical precipitation from water."

In 1858 H. D. Rogers described a possible method of the forma- tion of the fossiliferous iron ores of his "Surgent" series to be by the precipitation of peroxide of iron in the ocean. The calcareous and fossiliferous nature of those strata was to him an indication "that the epochs of the deposition of the iron ore were also the periods of the most copious supply of carbonate of lime," which would act as a precipitant of the peroxide of iron from solution.

These three statements are the only instances we have discovered in which the chemical precipitation of ferric oxide in the ocean has been assigned as a possible explanation of iron ore deposits — and here only theoretically or as an alternative view to some other rather to be preferred or supplementary to it

J. P. Lesley advocated the chemical precipitation of carbonate of iron to form portions of subterranean strata, and stated that iron might be found "in any of its mineral combinations in the oldest rooks without having resort to the igneous theory." B. S. Lyman is another who thought that the iron ores found in sedimentary strata, particularly in limestones, were precipitated in the form of carbonate of iron. This method of formation of iron ores was ap- plied by B. D. Irving to the ores of the lake Superior region. He

242 Bulletin No. Vi.

stated that he found traces of the original carbonate still left in the rocks in some places. Prof. C. R. Yan Hise also in a very ingen- ious and interesting paper upon the "Iron ores of the Penokee- Gogebic series of Michigan and Wisconsin"* expresses the view that "the iron formation deposits were originally an impure cherty carbonate of iron." The mistake made by Profs. Irving and Yan Hise is the same that has been made for hundreds of years, viz., too wide an application of a theory deduced from limited observa- tions. Because it was found satisfactory for one At of facts and for one class of ores they considered it valid for a somewhat differ- ent set of facts and for ores that belong to a far older formation. Prof. Van Hise, however, says he only suggested that the ores of the Tower region in Minnesota may have had a similar origin, though he and Irving both regard the Vermilion lake ores as of the same age as those to which they applied their theory in Wisconsin.

It is not quite clear whether Prof. Irving regarded the carbonate of iron as precipitated in oceanic water without tb& action of de- caying organic matter, or in surface waters in the same way that bog ores are now formed. He says: "These ferruginous rocks were once carbonates analogous to those of the Goal Measures." We are led to infer that he supposed the precipitation to have taken place in the presence of abtindance of decaying organic mat- ter. It appears, further, that iron carbonate is precipitated in presence of super-abundance of organic decay, but until then the precipitate is ferric oxide. (Compare J. S. Newberry, Proc. Lye. Nat. Hist of New York, Vol. 1, 1870-71, pp. 36, 37; Monograph XIV, U. S. Geol. Survey, pp. 7-8; Newton, Geology and Resources of the Black Hills, p. 138; I. C. Russell, Bull. 52, U. S. Geol. Survey, p. 45, 1889.)

Dr. M. E. Wadsworth may also be quoted as an advocate of this theory, though of what particular phase of it is not clear. He has said, however, that he holds that the iron ores of lake Superior "are chiefly eruptive, partly intrusive, partly in overflows; also formed in part by decomposition of the jaspilyte and ore in situ, and in part by mechanical and chemical deposition."

Under this general head comes also the theory adopted in this report ot the origin of the iron ores of the Keewatin. An outline of the process of formation which we believe is indicated by the nature of the rocks of that series and the relations it sustains to, the ore lenses may be given here without mentioning all of the phenomena which have led us to adopt this theory, f

4 *Am. Jour Sci. (ill)) : Jan. 1889, pp 32-48.

t For a farther statement of the views of the writers see Am. Geologist, Vol. IV, No. 5, 1889, pp. 291-300; Vol. IV. No. 6, pp. 382-385.

Iron Ores Of Minnesota. 243

We believe that the jaspilyte and ore lenses were formed at the same time that the enclosing rocks were deposited, and that they have undergone but very slight mineral or chemical modification since that time. There is in the rocks which surround and enclose the iron ore bodies indubitable evidence of the action of both vol- canic and aqueous agencies in their formation and deposition. In order to understand the circumstances under which the oxides of iron and silicon, which compose these immense deposits, were formed we must consider that it was at a very early age in the his- tory of the world; that the crust of the earth was thin, and contacts between molten material and the oceanic waters were frequent and the resultant disturbances violent; that the waters of the ocean were capable of dissolving a greater amount of silica and iron as well as of other ingredients than in modern times, because they were heated and liable to be charged with intensely solvent chemicals. The high temperature of the atmosphere and of the ocean's waters would prevent the precipitation of all the more volatile minerals, but oxides of iron and silicon would be formed and precipitated wherever evaporation or cooling of the oceanic waters took place. Currents would be formed in the ocean by the heat from fissures or proximity to volcanic vents as well as by the same causes which produce them in modern times. These currents would carry away warm saturated solutions heavy with their load of iron, silica and other substances into cooler portions of the sea, where precipita- tion would take place, and accumulations of mingled silicic hydrate and hydrous ferric oxide would be formed.

Other portions of the ocean's waters were heated and rendered capable of taking into solution still further amounts of iron and silica, two chief ingredients of the volcanic matter which was being continually or at intervals erupted and deposited in the bed of the ocean.

In this way can be understood the minute interbanding of dark ferruginous and lighter silicic bands in the jaspilyte, also the minutely fine granular structure of the silica, the occasional dis- semination of this silica through the green schists and in fact nearly if not quite all of the varied phenomena observed in connec- tion with the ore and jasper lenses of the Keewatin.

Subsequent pressure alone is sufficient to dehydrate the oxides, and aside from that we believe very slight changes have affected the general masses of the ore or the rocks of the whole formation. The occurrence of the ores and jaspilytes in lenticular masses is easily explained when we consider the action of the oceanic cur- rents. It is what is always found in true subterranean deposits

244 Bulletin No. Vi.

Prof. Julien says in this connection: "The strongly marked len- ticular form and laminated structure of ' all deposits of crystalline iron ores — and even of the numerous smaller lenses, parallel or overlapping, which make up the large deposits — are unmistakably characteristic of marine accumulation, Neptune's own royal stamp." The careful researches of Prof. R. D. Irving impressed him very strongly with the fact that the silica of the jaspilyte was chemi- cally deposited from bodies of water. A few quotations from his article in the American Journal of Science in October, 1886, on the "Origin of the Ferruginous Schists and Iron Ores of the Lake Su- perior region" wiJl suffice to show this. "The silica, which fre- quently forms so prominent a part of the ferruginous schists, and which is at times jaspery, but is far more frequently cherty or even chalcedonic — a point hitherto quite unrecognized in publications on this subject — presents every evidence, both in the thin section and in the field, of a chemical origin. In the thin section — in that it shows ordinarily no trace of a fragmental texture, even when relatively coarse-grained, and in that it approaches more commonly to the peculiar chalcedonic or even amorphous forms known to occur only with silica deposited directly from solutions; besides which it traverses and follows the banding indifferently and in such a manner as to place its secondary nature beyond all doubt. (?) The facts above cited prove incontest- ably the chemical origin of the silica. We were thus re- stricted to some theory which should account for the precipitation of most of them essentially in their present conditions, with per- haps some slight internal rearrangement; or to one in which the production from some form of sedimentary deposit of the condi- tions obtaining, should be assigned to metasomatic processes, carried out, in part at least, at a very remote period. While we have, perhaps, in the deposition from some modern siliceous springs, a slight analogy to the interstratification of iron sesqui- oxide and silica, this analogy is, after all, but slight and there is nothing in the structure of these deposits to indicate spring deposition, and everything to indicate deposition in bodies of water. But of the formation of such deposits by chemical deposition in bodies of water we certainly have no modern in- stances. Later, as further study developed the fact that the least altered forms of the ferruginous schists contain a consid- erable proportion of some carbonate — the amount of carbonate increasing inversely with the amount of disturbance and alteration — the idea of a possible formation of these rocks by chemical deposition approximately in their present conditions gave place to

Iron Ores Of Minnesota. 245

views which included the idea of a replacement of some jock, originally dolomitio or calcitic, by siliceous and ferruginous sub- stances."

It thus appears that Irving was almost driven to accept the theory of chemical deposition of the ore and jasper in the ocean in sub- stantially the same condition that they exhibit in the rooks at present. But, because there is no example in modern times of just such a deposit, and because he found carbonates in connection with some of the iron ores (Huronian) he abandoned conclusions at which he had correctly arrived, and which were valid for one set of rooks (Eeewatin) in which he saw the other phenomena. Un- fortunately he tried to make the phenomena and chemical conditions of one class of ores (Huronian) produce a theory to cover ores and phenomena that pertain to an older formation. He was con- tinually misled by his inability to separate these two great geolog- ical formations, and to distinguish the differences in their respective ores.

It was suggested by W. A. Crosby that the ferruginous nodules in the deep-sea ooze might furnish a clue to explain the formation of the jaspery iron ores; but there is no clear relation between the continuous laminations and banding of the jaspilyte and the scat- tered nodules of the ocean bottoms to-day, though with proper modifications this germinal idea may be applicable in a wide sense.

9. Deposit from springs. It has been observed that around the mouths of springs oxide of iron has been precipitated by oxida- tion from solutions of ferrous carbonate or by mechanical deposi- tion of minute particles of ferric oxide brought out by the water. Bischof mentioned such deposits and suggested that they might aid in the formation of iron ore beds. But it is evident that if the world's supply of iron had to be derived from this source, we should n ever hear of an "Iron age."

10. Alteration of diffused ferric oxide into ferrous carbonate. The only geologist who has been found to advocate this method of the formation of iron ore deposits is W. B. Rogers. He supposed that carbonate of iron was produced by thi reducing action of or- ganic matter brought in contact with it in situ in the rocks and not in infiltrating waters. Forces of segregation afterward ac- cumulated it in irregular strata. He accounted in this way for the iron ore of the Goal Measures.

His explanation has not been accepted by any one so far as we know, and could not apply to ores enclosed in rocks which were deposited before the presence of organic life on the earth.

246 Bulletin No. Vi.

1L Meiamorphism of ancient bog ores. It was suggested by Robert Bakewell in his Introduction to Geology, 1833, that iron- stone may have been " the produce of decomposed vegetation as bog or peat-iron is supposed to have been.'1 But he disclaims for him- self and brother geologists any certain knowledge of the mode of its origin. Dr. W. Kitchell in 1856 " opposed the theory of the igneous or eruptive origin of the magnetic ores of New Jersey, maintaining that they ' were of sedimentary origin and had been deposited just as the gneiss and crystalline limestone had.'

Twelve years later Prof. Geo. H. Cook supported the views of Dr. Kitchell and remarked that "the magnetic iron ores of this state (New Jersey) have originated from chemical or mechanical deposits, just as our hematites and bog iron ores do now."

In 1869 T. S. Hunt championed this view and put forth many arguments to sustain it. His views on the subject have frequently been quoted and will be found in full extracts under his name and that of Julien in the appended Bibliography.

Since Hunt many prominent geologists have held this view, among them are J. D. Dana, J. S. Newberry, Jos. Le Conte and A. Geikie. With such an array of eminent authorities to support it it would seem as though it were inevitably sound and valid. But while it may be true and very likely is, that iron ores may be rendered crystalline and massive by metamorphism and that some deposits of magnetic ores associated with Palaeozoic rocks have been changed from bog ores by contact with recent eruptions, it is quite certain that all crystalline iron ores cannot be explained in this way, and that the presence of iron ores in Archaean rocks is no more evidence of the existence of organic life at that age than the presence of quartz or any other oxide.

Some geologists have been so carried away by their desire to discover evidences of the existence of life upon the globe much earlier than there is any reason to believe it did exist, that they ignore other more possible and more probable methods of the for- mation of per- oxide of iron, and overlook features in the rocks themselves that are incompatible with the existence of life at the time they were being deposited.

The frequent occurrence of graphite in intermixture with the crystalline iron ores and in rocks of Archaean age has been cited by the advocates of this theory as proof positive or at least strongly indicative of plant and animal life at that early period. But on this point Prof. Julien says: The general absence of

Julien op. dL This theory is put by Julien in this category, though it might be classed under Theory No. 8.

Iron Obe8 Of Minnesota. 247

graphite "seems to prove that it cannot be chiefly derived from the organic matter (1 to 36 per cent.) contained in all limonites, bat rather, it may be, from the algae and marine plants sometimes finding their growth and entombment in the iron-sands, even of iron oxide, in shallow water."

The discovery of graphite in meteorites, as remarked by J. Lawrence Smith, has an important bearing on this question and proves that it is not at all necessary to suppose that graphite is only to be derived from the remains of animals or plants. Dr. M. E. Wads worth says:* "To make graphite the evidence of life is the same kind of argument as it is to claim that no oxides of iron and no carbonate of lime could be formed without the intervention of life. One we knew to be oftentimes of volcanic origin, and the other to be frequently the product of the decomposition of rocks."f In Whitney and Wadsworth's "Azoic System" (Ball. Mus. Comp. Zool, Vol. VII. 1884) the subject of graphite and its value as an indication of life is fully discussed, and the conclusion is reached that there is no proof whatever that graphite is the result of the decomposition of vegetable matter. They state: "That we know of no other way in which graphite can be artificially formed than in- directly in connection with, or as one of the .results of, some pro- cess or operation carried on at a very high temperature:" There is thus no reason why it may not have constituted a primary con- stituent of the earth.

The idea that iron ore is an indication of life is thus disposed of by the same writers: "In default of other evidence of the presence of the results of organized existence in the azoic rocks, it has been maintained by some that the occurrence of ores of iron in extraordinary quantity in that series furnished the desired proof. The facts are, however, that some at least of the iron thus occur- ring is of eruptive origin; that the oxide of iron is a mineral commonly and abundantly found making an essential com- ponent of volcanic rocks; that metallic iron is so found in large quantity, — in one region, at least; that there is strong reason for believing that metallic iron forms, if not the whole, at least a large part of the earth's interior; and finally, that a large portion of the materip1 . uich comes to us from outside our planet is metallic iron. Al! ms, we think, is amply sufficient for a refutation of the theory,

Llthologlcal Studies, p. 67.

tOn thin point Hunt says: (Am. Joum. Sci. (Hi) ix, 1880. p. 853) "While some have magined an Inorganic origin to the carbon found In the form of graphite, and, evon to petroleum and to coal, sound reasoning is, we think, on the side of those who, start- ing from the conception of an orglnally oxidized globe, see no evidence of any process of deozldatlon therein which does not, directly or indirectly, depend upon vegetable life, And hence assign an organic origin to all carbons and hydrocarbons."

248 Bulletin No. Vi.

tbat the presence of the ores of iron is a proof of the existence of life at the time when the rocks were formed in which those ores occur."

In the face of such facts as are mentioned above the reiterated statement of Le Conte that "both now and aluoays iron ore is and has been accumulated by organic agency" appears to be the result of an insufficient examination into the fundamental principles of chemical geology.

One reason why geologists have clung so tenaciously to the action of organic matter is because it has seemed necessary to have some way to reduce the iron from the sesqui-oxide to th# protoxide condition, in order to get it into solution. This was wholly unnecessary labor on their part and only involved them in greater difficulties. The iron contained in the various basic rock- oomposing minerals of the silicate order is already in the protox- ide or soluble condition, and ordinarily becomes oxidized or changed to the insoluble peroxide when the mineral disintegrates and its soluble ingredients are removed in solution by meteoric waters. But if the iron were dissolved before it had a chance to become insoluble there would be no reason why it could not be carried off aud added to some other iron obtained in the same way and the whole deposited by evaporation and precipitation in the shape of a bed of ferric oxide.

During the Keewatin period especially would this action have taken place upon a large scale; the basic material thrown into the tnrbuleut ocean would be largely dissolved by its alkaline waters* and the iren of the silicates or possibly from the metallic state, would be easily taken up and held until the waters were forced to abandon it because of cooling or the accession of carbon- ates from the atmosphere or neighboring shares where disintegra- tion was already goiug ou.

li "f*c' t%<tivorp\ism or anwvif ?<iJbMfrj*Krife. It is qui possible that the liuionite of the lake ores should be metamor phoeed and changed to hematite, and rerr likely that it would soluble the oolitic fosailifereus ore of the Clinton; bat it does n seem probable that this theory will for so many deposi of orxstalliue ore as Prof* Juliet* claims. Lake ores are foim largely :ne actKxu of orsatxic raatter* aad we have seen that tfc* a: re of :he rook* <vttfaiut3£ of the !anje deposits of ta":* irvs ore axsd the terrestrial vv*xli:x> which they indi are such as to preclude the of viat or aniznal life at tl* tiuie of :he:r acvusitulanott- fbe $erer*I trwdomof tike ores

Iron Ores Of Minne80Ta. 249

another reason why they oannot have originated in this way, since these are both found to a considerable extent in the Scandinavian lake ores.

13. Violent abrasion and transport. This theory of Whit- ney's has been discussed by Lesley, Julien and Wads worth, and their remarks upon it will be found under the former two names in their proper place in the Bibliography. So far as we know it has not been adopted by any geologists, nor does it appear that Whit- ney intended it; to account for any large deposits of iron ore.

14. Concentration and metamorphism of iron-sands. The first to propose this explanation of the origin of iron ore beds seems to have been Mr. B. J. Harrington, in the report of progress of the Canadian Geological Survey for 1873* The opinion there ex- pressed is as follows: "It seems possible that, in some cases, beds may have been formed by the accumulation of iron sands, just as they are forming in the gulf of St. Lawrence to-day, the material being derived from the disintegration of pre-existing crystalline rocks. Such beds we should expect to contain not only magnetite but ilmenite, and it is well known that in many oases ores, on be- ing pulverized, may be more or less completely separated into a magnetic portion, containing little or no titanic acid, and a non- magnetic portion consisting essentially of ilmenite. It seems, how- ever, probable that in general their origin has been similar to that of the modern bog and lake ores."

This view Prof. A. A. Julien has adopted and elaborated. He has imagined that "the conditions (of the Huronian ores and their formation) consisted of a shore of some quartzose rock, rich in magnetite, whose debris the waves and currents strewed over the sea-bottom, alternately with thin sheets of quartz-granules and magnetite- crystals, partially concentrating the one or the other material in numerous heaps or thicker layers.

Iu the progress of the metamorphism and contortion to which the layers were subjected, their compact and lenticular forms were further developed, the magnetic oxide was further oxidized, par- tially as martite,or completely as specular ore (as already suggested by Brooks, Credner, aud others), and assumed, at points where the contortion and pressure became intense, the micaceous structure and brilliant lustre of micaceous iron ore, by a process similar to that which produces 'slickensides.'

Previously to this however. In 1865, J. P. Kimball had advanced views of the origin of part of the iron ores of Michigan which contained the idea set forth later by Har- rington and Julien. Speaking of ferruginous conglomerates of the region he said: "They to be of littoral formation and to have been derived from dismembered and crum-

bled deposits of successive laminae of jasper and iron ore.*' He hardly went so far as to conclude that the shore detritus was reduced to sand, since much of the conglomerate Is more like a breccia, but the Idea of beach accumulations subsequently consolidated and incorporated in the later strata was plainly expressed.

250 Bulletin No. Vi.

The concentration of nearly pure magnetite in the deposits enclosed in the lower Laurentian strata of Canada and the Adiron- dacks, and of titaniferous magnetite or menaccanite in the huge ore-beds associated with the anorthosites of the upper Laurentian in both regions, point unmistakably to mechanical separation of ferriferous sediments from different terranes; i. e.f in the one case from the magnetitic gneiss, in the other from the traps and anor- thosites, rich in menaccanite. An examination of thin sections of diabase from dykes cutting pure magnetites in Essex county, N. T., showed this rock to be rich in menaccanite and a possible source of such sediments.

No concentration of titanic acid has ever been found in limonites or bog-ores. These facts seem significant of the insufficiency of any chemical theory to account for the origin of all the iron ores."

Iron ore deposits formed in the manner indicated above would at present be found in sedimentary or metamorphic rocks, but in no case inclosed in eruptive rocks. As Prof. Julien says: "The rock- strata, associated with all these varieties (of iron ore), are undoubtedly of marine origin." But the titaniferous iron ores are found invariably in rocks of admitted eruptive origin. The anor- thosites of the "Upper Laurentian," to which he refers, are the analogue of the titaniferous gabbro and associated gneisses of Minnesota. Prof. Julien himself says titanic acid is not found in limonites or bog ores; but we go still farther and say that we believe that there are no deposits of titanium-bearing magnetite yet known, which cannot be shown to be of eruptive origin. The evidence for that statement is derived from an examination of many hundred analyses and the examination of a great many iron ore deposits, as well as by comparison with published descriptions of all other regions.

The titaniferous ores are therefore excluded from this category, and the only other iron ores claimed by the upholders of this theory as examples of ores formed in this way are "the deposits enclosed in the Lower Laurentian strata of Canada and the Adirondacks."

The rocks of this terrane are the oldest rocks known to geology. There may have been earlier formed strata or massive rock-bound Coasts which were disintegrated and whose mineral constituents were able to furnish the iron ore now found in the Lower Lauren, tian. But until it is proved that such rocks did exist and that they could have furnished the sands and iron ore for the oldest deposits now known, we cannot place any great weight upon their merely conjectured existence and nature.

Iron Ores Of Minnesota. 251

Again, as already remarked, under No. 4, this theory does not account for the origin of the ore, but leaves the essential question still unanswered, viz: the genesis of the original iron-bearing rock which gave off the debris to form the iron-sand.

There can be no question that in the Marquette iron district is a great fragmental stratum made up, as described by Kimball, and as accepted by Julien, of debris consisting largely of iron ore, pre- senting the characters of a littoral accumulation. Some portions of this stratum are found to be so largely composed of iron ore that considerable quantities have been used for merchantable ore. But it has been found that this stratum is no part of the iron forma- tion of the country. It is the conglomeratic lower portion of an unconformable wide-spread quartzyte and conglomerate formation which everywhere manifests the same tendency to take on the characters of the older rocks on which it may happen to lie. In the iron region it is made up largely of iron-ore debris. Any theory applicable to it may not be applicable to the true iron ore formation that unconformably underlies it.

15. True veins formed by chemical segregation or secretion. This is a relic of the early days when all ore deposits were sup- posed to be in veins of one kind or another, having a deep-seated connection with the centre of the earth. It is, however, not the worst form of that theory, for veinlets of iron ore are found in many iron ore deposits where cracks and crevices of different age and size have been filled up by infiltration and chemical deposi- tion. In a few cases quite considerable fissures have been filled in this way with limonite or with hematite and siderite, but it is sel- dom the fliase that deposits of magnetite or specular hematite are found to have the characteristics of true veins. It is true that the miners almost universally speak of "hanging walls" and "foot walls," of "horses" of rock and of "faults." But these terms must all be used in an accommodated sense, when they are not entirely in- applicable. Many of them were imported to this country by the miners of Cornwall, and their persistent use has often been the cause of mistaken ideas of the true structure and origin of the ores to which they have been applied. It can be questioned whether there is any known merchantable deposit of iron ore that origin- ated in the manner of a true segregated vein.

16. Electro- telluric action,i. e.t as a result of the reactions and decompositions produced by electro-magnetic currents in the earth. The rather vague processes supposed to transpire in the earth's strata on account of electric currents, have at times been invoked to account for ore deposits of all kinds. This was principally before

Bulletin No. Vi.

the working of electrical forces was as well understood as at present. The name of Mr. E. W. Fox is inseparably connected with this theory, as he made quite a hobby of it, and maintained its validity for many years in the early part of this century. He supported his arguments by many experiments demonstrative of the decom- posing power of electric currents. His theory was accepted by some of the early English geologists. W. J. Henwood and Profes- sor Reich pointed out many objections to Fox's theory and it has eeldom been seriously considered in recent years.

Dr. Carl Barns in a paper read before the American Institute of Mining Engineers in 1884 gives many clear ideas on the subject. He says: "There can be little doubt that the hypothesis which ascribes to ore-currents a hydro-electric origin is perfectly correct." But he found that the electro-motive forces are so weak that it is difficult if not indeed impossible to arrive at a correct estimate of the effect really produced in this way.

In this connection, of course, the disturbing action exerted upon the compass by deposits of magnetite is to be remembered. This power of magnetite is frequently the only thing which leads to its discovery, buried as it often is under several feet of soil or drift material. B. Thalen made some interesting observations on this means of discovering bodies of iron ore. " He found that the lines of equal magnetic intensity, in the vicinity of the ore deposit, con- tracted to two sets of closed curves, disposed with reference to two very satisfactorily indicated foci." It is not very clear how the present magnetic activity of iron ore bodies can be made to explain in any way their origin.

17. Substitution of ferrous oxide for lime in the original rock and change to peroxide. This secondary process has been shown to be a natural and easy method of accounting for accumulations of iron ore in rocks which were originally carbonates. It was sug- gested in the 15th Minnesota Beport (p. 216) as the probable origin of the Keewatin ores at Tower. It is somewhat allied to No. 4, but involves also the carrying of iron in solution to take the place of the removed calcium carbonate. This theory may very properly be applied to ores of comparatively recent date whose environments indicate the former existence of a carbonate in the rock; but the Lauren tian and Keewatin rocks proper are not found to contain limestones which could have been acted upon in this way, and such limestones as they do contain show no indi- cations of such transitions. Indeed, the nature of these rocks indi- cates that in Minnesota the environments were such that deposits of carbonates of lime and iron could scarcely have been precipi-

Iron Ores Of Minnesota. 263

ated abundantly, much less acculated mechanically at the time the rocks were formed.*

In any case the source of the iron which may thus have been substituted for lime is not satisfactorily accounted for, though per- haps it would not be difficult to do so. This theory is applicable as urged by Irving and Van Hise, to the ores of the Huronian Taoonic) in the lake Superior region.

18. Secondary product from the decomposition of basic rocks, eruptive or metamorphic, and concentration of the oxide of iron in drainage basins. Although this idea was suggested or implied in the descriptions of iron ore deposits, by several geologists, and al- though the decomposition of basic rocks is understood by all to fur- nish the iron which is now being accumulated in marshes and bogs, yet there is but one or two who have insisted upon it as explanatory of deposits of crystalline ores. It is indicated by Dr. A. Schmidt as being part of the process of formation of the iron ore deposits of Missouri. Mr. J. P. Kimball has given the clearest statement of this method of formation in the older rocks. It is as follows: "The large bodies of hematite or specular oxide, together with associated ferruginous aggregates, in part, of maguetic oxide, are secondary products from the decomposition of basic eruptive rocks, now rep- resented by the epidotic diorite, which has penetrated and over- flowed the ey en i tic base of this part of the Sierra Msestra. They are the result of the alteration or epigenesis of highly basic, and therefore unstable rock-aggregates, and of their resolution into new aggregates with the aid of surface agencies, in subordination to the new conditions met with at and near the surface. Thus the presence of oxygen in atmospheric air, and of alkaline and earthy bicarbonates from decomposing silicates, has rendered unstable the highly ferriferous material from deep-seated sources. These aggregates were basic from excess of protoxide bases, and especially protoxide of iron. Such eruptive material cannot long resist fur- ther oxidation at the surface, with the result of more or less com- plete disintegration of the original aggregate, and its recomposition into new compounds To be more specific, the erup- tive material which gave origin to the iron ore consisted of proto- flilioates, or silica combined with the protoxide'bases, iron, lime and magnesia, and with alumina. Under its new conditions at the sur- face, with access to oxygen in the atmosphere and in circulating Waters, and in contact with bi-carbonates of the alkalies and of alkaline earths, (also circulating in meteoric waters, and derived

The to-called Laurent! an limestones of Canada are apparently an anomalous ex- ception; but there Is reason for suspecting that they may not bo of Luurciithm aj?.

254 Bulletin No. Vi.

in part from itself, but especially furnished in large proportion by still more f eldspathic material like syenite in the process of weath- ering), the protoxide of iron became rapidly further oxidized into ferric or sesqui-oxide, which is a comparatively stable product under conditions prevailing at the surface. The oxidation of the ferrous to ferric oxide is attended with more or less complete dis- memberment of the eruptive rock, little by little. Silica originally combined with the ferrous oxide is isolated as silica. Silicates of lime, magnesia and alumina, being more stable, form new aggre- gates among themselves, in part according to atomic proportions."

This outline of the method of the extraction and concentration of iron oxide is correct and valuable, as it gives hints of the chem- istry involved, some of which is similar in its reactions to those changes which are supposed by the writers to have taken place in the oceanic waters of the time of the Keewatin. This theory as pre- sented by Dr. Kimball is probably quite valid for the surface deposits of iron ore to which it was directly applied, but there are various rea- sons why it cannot apply without considerable exception to those of Michigan, Wisconsin and Minnesota. From what has gone be- fore these reasons will easily suggest themselves to the reader, e.g., the fact that the rocks of the Keewatin have not undergone much decay since they were cleanly abraded by glacial action, and that the iron ore bodies sustain such intimate relations with the enclos- ing rocks as to afford good evidence that they were deposited con- temporaneously. The work of decomposition and solution and recombination and precipitation must have gone on in the heated wators of the ocean, which would have an effect similar in some respects to that of percolating atmospheric waters, but much more intense and on a vastly larger scale.

The hypothetical origination of the ore, under this theory is, however, identical with that adopted by the writers. The chief difference consists in this: That Kimball supposes the ore to be not indigenous in the rock in which it is found, but a secondary pro- duct. We suppose the iron ore of the Keewatin to be indigenous, and one of the coeval constituents of the rock in which it occurs. He postulates some secondary, superficial "drainage basins", sub- ject to meteoric agencies. We only need the ocean, and the same forces as those that originated the rocks of Keewatin time.

Concluding Observations.

From a perusal of the foregoing it will be seen that of the eighteen distinct methods which have been proposed to explain the accumulation of ferric oxide in massive deposits, eight or ten are

Iron Ores Of Minnesota. 255

based on sound chemistry and a correct interpretation of physical facts and may be valid theories for some particular deposits of ore. It is also seen that the general tendency of opinion has been away from Hutton's theory of igneous injection or eruption toward the various chemico-sedimentary theories, and that of these the theories receiving the most general support are numbers eight and eleven, derivation from original deep sea deposits and metamorphism of ancient bog-ores. It is also evident that no thoughtful person can ever again attempt to explain all deposits of iron ore on any one theory, because iron is a metal of such wide distribution and ready chemical affinity,and of such varied forms of combination that it may be acted upon by every agent of solution or decay, as well as of precipitation or mechanical deposition.

Another result that has been made clear, based upon evidence of incontrovertible fact and weighty opinion is that organic matter is no more necessary for the production of iron ore beds than it is for the formation of beds of quartzyte, and that iron ore accumula- tions in the Archaean rocks are no indication whatever of the exist- ence of animal or vegetable life at that period of the world's history. This idea springing fipm the observed action of organic matter in the formation of bog ores, has had the same history as those that sprung from other limited observation and study. It has been used to account for all iron ores. It has to be restricted to the limits which its very limited applicability can be said to establish.

On the whole we believe that a review of the various theories held at different times upon this subject shows that there has-been in recent years a great advance, and an approach to more generally correct understanding of the ways in which iron ore may have been accumulated in the past and is being formed at present

A tabulated list of the various advocates of the eighteen theories discussed in the foregoing pages is placed here for the purpose of showing at a glance what geologists have supported the different views. By reference to the bibliography which follows, the place where each opinion referred to was published may be found, and often a direct quotation bearing upon the point in question.

Bulletin No. Vi.

List Of Advocates Of The Various Theories.*

Theory No. 1.

C. J. B. Kara ten, 1853. (Cerro de Mercado.)

A. £. Nordenskiold, 1872. G. Tachermak, 1874.

Theory No. 2.

Li. Moro, 1740.

J. Hutton, 1795.

W. W. Mather, 1839.

Le Play, 1844.

Sir B. Murchison, 1845.

Burat, 1845.

Elie de Beaumont, 1847.

Durosher, 1849.

Poster & Whitney, 1851.

T. Andrews, 1852.

Fr. C. L. Koch, 1853.

J. D. Whitney, 1855.

£. Emmons. 1856.

Dr. Deck, (Beck?) 1857.$

H. D. Kogers, 1858.

H. Weidoer, 1858.

B. Von Cotta, 1864. S. H. Daddow, 1866. Benj. Ban nan, 1866. Ohas. Whittlesey, 1867. tWalter Flight, 1875. J. O. Smock, 1875. A. Daubrf'e, 1875.

K. J. T. Steenstrup, 187o . Fabre, 1876.

A. Sjogren, 1876. Jos. Szabo, 1876. Tombeck, 1876. tOhancourtois, 1877. tRohde, 1877.

J. W. Dawson, 1878. |J. L. Smith, 1878. M. E. Wadsworth, 1880. |J. W. Judd. 1881. P. Frazer, 1883. |H. Hensoldt, 1889.

Theory No. 3.

Lehmann, 1753. Prof. Necker, 1832. Dufrenoy, 1834. Douglass Houghton, 1841 Le Play, 1844. Burat, 1845.

Elie de Beaumont, 1847. Durocher, 1849. Foster & Whitney, 1851. J. D. Whitney, 1855. E. Emmoos, 1856.

B. Von Cotta, 1864.

fi

O. A. Corneliuasen, 1877. J. W. Dawson; 187a Eugene Coste, 1887.

Theory No. 4.

R. M. S. Jackson, 1838. L. Vanuiem, 1838. G. Bischof, 1847. Chas. Whittlesey, 1867. J. P. Leslev. T. B. Brooks, 1873. R. Pampelly, 1873. J. W. Harden, 1874. O. Le Neve Foster, 1875. S. F. Emmons, 1876.

A. Firket, 1878. Eugene A. Smith, 1878. O. E. Wright, 1879. H. O. Lewis, 1880. M. E. Wadswortb, 1880. J. P. Kimball, 1884. C. R. Van Hise, 1889.

Theory No. .5.

L. Vanuxem, 1838. J. M. Safford. 1856.

B. Von Cotta, 1864.

A. Schmidt, 1872. J. P. Kimball, 1884.

Theory No. 6.

Elie de Beaumont, 1847. Durocher, 1849. Von Deohen. 1851. J. M. Safford, 1856. H. D. Rogers, 1858.

B. Von Cotta, 1864. A. Schmidt, 1872.

F. Prime, Jr., 1875.

C. R. Alder Wright, 1885

Theory No. 7.

C. U. Shepard, 1837.

G. Bischof, 1847. H. D. Rogers, 1858. T. S. Hunt, 1869. P. Frazer, 1875. .F. Prime. Jr., 1875. S. F. Emmons, 1876. A. Firket, 1878. H. C. Lewis, 1880.

Theory No. 8.

Dr. E. Hitchcock, 1833. C. U. Shepard, 1837.

J. W. Foster, 1849. J. D. Whitney, 1855. W. W. Smyth, 1856, H. D. Rogers, 185a B. Von Cotta, 1864. J. P. Lesley, 1866.

B. S. Lyman, 1867. Chas. Whittlesey, 1867. A. Winchell, 1&70.

C. Le Neve Foster, 1875.

F. Prime, Jr., 1875. H. Credner, 1875.

A. Sjogren, 1876. O. E. Wright, 1879. W. O. Crosby, 1879.

M. E. Wadsworth, 1880. J. A. Phillips, 1884. O. R. Alder Wright, 1885. R. D. Irving, 1886. C. R. Van Hise, 1889. N. H. Winchell & H. V. Winchell, 1889.

Theory No 9.

G. Bischof, 1847. Theory No. 10.

W . B. Rogers, 1857.

Theory No 11.

Robt. Bakewell, 1833. Dr. W. Kitchell, 1856. Hausmann, 1860. Geo. H. Cook, 1868. T. S. Hunt, 1869.

B. J. Harrington, 1873. J. D. Dana, 1874.

O. Gumajlius, 1875. J. S. Newberry, 1875. Jos. Le Conte, 1878 A. Geikie, 1882. Jeremiah Head, 1887.

Theory No. 12.

Hausmann, 1860. Ed. Hull, 1876.

A. A. Julien, 1882.

Theory No. 13. J. D. Whitney, 1855. Theory No. 14.

J. P. Kimball, 1865.

B. J. Harrington, 1873. A. A. Julien, 1882.

♦For a statement of these theories see page 224.

♦Metallic Iron in Basalt.

FSee Lesley. Iron Manufacturer's Guide, page 407.

Iron Ores Of Minnesota 257

Theory No. 15. Becquerel, 1835. Theory No. 18,

EL T. De La Beche, 1839. F. W. Smyth, 1858. Man. De Castro, 1878. A. Schmidt, 1872.

B. Von Gotta, 1864. J. P. Kimball. 1884.

Ed. Hartley, 1867. Theory No. 17. N. H. Winohell and

A. Schmidt, 1872. H. V. Winohell, 1889.

P. Wurzburger, 1874. G. Biachof , 1847. J H. Collins, 1875. A. Schmidt, 1872.

(J. R O.Tiohborne91877. J. D. Kendall, 1874. a B. Alder Wright, 1885.W. H. Hudleeton, 1875.

P. N. Moore (no date). Theory No. 16. J. P. Kimball 1884.

N. H. Winohell, 1886. R W. Fox, 1822. L O. Russell. 1889.

17

Part V.

Bibliography Of The Origin Of

Iron Ores.

Note.

So far as known this is the first attempt at a bibliography of the origin of iron ores. It contains, besides the titles of articles and books treating directly and exclusively of the origin of iron ores, the titles of many works that refer only in- cidentally to their origin, and of others that do not discuss their origin at alL It was considered useful to list such because of their value and authority on some of the aspects of iron ore, or because of their treatment of the phenomena of its physical structure which is inseparably connected with any inquiry into their origin. Many of these works have not been seen, particularly those pub- lished in foreign countries, and their titles have been copied from other refer- ences, principally from the "Geological Record," London, 1875 to 1889. The list cannot be considered complete, but it contains every title that has fallen un- der our notice, and is more nearly complete for works published since 1872.

There are some smaller papers in such publications as the bulletins of the United States Census,of the American Iron and Steel Association, Iron, and the Engineering and Mining Journal, and others, that are here generally not included.

List of Abbreviations.

A. A. A. S. American Association for the Advancement of Science.

Acad. Sci. Berlin. Academy of Science, Berlin.

Am. Assoc. Adv. Sci. American Association for the Advancement of Science.

Am. Ckem. Jour. American Chemical Journal. Baltimore.

Am. Oeol. American Geologist. Minneapolis.

Am. Inst. Min. Eng. American Institute of Mining Engineers.

Am. Jour. Sci. American Journal of Science and Arts. New Haven.

Am. Nat. American Naturalist. Philadelphia.

Ann. de Chimie. Annales de Ghimie et de Physique. Paris.

Ann. Lye. Nat. Hist. Annals of the Lyceum of Natural History. New York.

Ann. Mines. Annales dee Mines. Paris.

Ann. Rep. Brighton Nat. Hist. Soc. Annual Report of the Brighton and Sussex Natural History Society. Brighton.

Ann. Sci. Disc. Annual of Scientific Discovery.

Ann. Soc. QSol. Belg. Annales de la Socidte* Geologiquede Belgique. LUge,

Ann. Soc. OSol. oVNord. Annales de la Soci6t6 Geoiogiaue da Nord, Lilte.

Atti! Soc. Ital. Sci. Nat. Attidella Societa Italiana di Soienze NaturaH. Milan.

Iron Ores Of Minnesota. 259

Berg. u. Huttenm. Zeit. AUgemeine berg- und huttenm&nnisohe Zeitung Quedlinburg.

Berk. Hist, and Sci. Soc. Berkshire Historical and Scientific Society.

Bihang K. Svenska Vet.-Akad. Handl. Bihaog till det Kongliga Svenska Yetenskaps-Akademiens Handlingar.

BoL Com. Map. geol. Espan. Boletin de la oomision del Mapa geologioo de Espana. Madrid.

Boll. R. Com. geol ItaL Reale Comitato geologioo d' Italia. Bollettino. Rome.

Brit. Assoc. Adv. Set. British Association for the Advancement of Science.

Bull Am. Iron Steel Assoc. Bulletin of the American Iron and Steel Asso- ciation.

Bull. Mus. Comp. ZooL Ballet in of the Museum of Comparative Zoology, Harvard College. Cambridge.

Bull. Soc Etud. Sex. Angers. Bulletin de la Socitfte' dee Etudes Scientifiquee d'Angers.

BulL Soc. Geol. France. Bulletin de la Socie'te' Geologique de France. Paris.

Bull. Soc. Geogr. Bulletin de la Socie'te' de Geographic. Paris.

Bull Soc. Ind. Min. St. Etienne. Bulletin de la Socite" de Industrie min- £rale de St. Etienne.

BulL Soc. Sci. Nat. Neuchatel. Bulletin de la Socite" dee Sciences Natur- elles de Neuchatel.

BulL Soc. Sci. Nat. Sud Est. Bulletin de la Sooi&e* dee Sciences Naturelles du Sud-Est. Grenoble.

Canad. Journ. The Canadian Journal of Science, Literature and History. Toronto.

Can. Nat. and Geol. Canadian Naturalist and Quarterly Journal of Science, MontreaL

Chem. News. The Chemical News and Journal of Physical Science. Lon- don.

ColL Guard. The Colliery Guardian and Journal of the Coal and Iron Trades. London.

CompL Rend. Oomptee Rendus hebdomadaires dee Stances de l'Acadlmie des Sciences de llnstitut de France. Paris.

Compt. Rend. Soe. Ind. Min. Comptes Rendus mensuelles des reunions de la Socie'te' de P Industrie Mine'rale de St. Etienne.

Corr-Blatt. Nat. Ver. preuss. Rheinl. Correspondenz-Blatt des naturhisto- rischen Vereins der preussisohen Rheinlande und Weetfalens. Bonn.

Emul. Jurass. I/Emulation Jurassienne. Delhnont. Eng. Min. Jour. The Engineering and Mining Journal. New York. Ex. Does. Executive Documents published by the United States Govern- ment. Washington.

r

FdldL KdzL Fdldtani Kozlonye (Geological Magazine.) Budapest

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m.

GeoL Nat. Hist. Bur. Minn. Geological and Natural History Survey of Min- Minneapolis.

GeoL Can. or UeoL Sur. Can. Geological Survey of Canada. Ottawa.

GeoL Roe. Geological Record. London.

GeoL Sur. Mich. Geological Survey of Michigan.

GeoL Trans. Transactions of the Geological Society. Londort.

Qomop Journ. Gornoy Journal, izdavaemy Uohenim Komitetom, Korpus

oufkh Injenerov. St. Petersburg.

260 Bulletin No. Yi.

Iron. Iron, The Journal of Science, Metals and Manufactures. London.

Jaarb. Mijn. Ned. O.-Ind. Jaarboek van net Mijnwezen in Nederlandsch Oost-IndiS. Amsterdam.

Jahrb. k. k. geol. Reich*. Jahrbuch der kaiserlioh-kSniglich geologischen Reichsanstalt. Vienna.

Jahresh. Ver. Nat. Wurtt. Jahreshefte dee Vereins far Vaterl&ndische Naturkunde in Wllrttemberg. Stuttgart.

Journ. Iron Steel Inst. Journal of the Iron and Steel Institute. London.

Journ. R. Geol. Soc. Ireland. Journal of the Royal Geological Society of Ireland. Dublin.

Journ. Soc. Arts. Journal of the Society of Arts. London.

Journ. U. S. Assoc Charcoal Iron Workers. Journal of the U.S.Association of Charcoal Iron Workers. Harrisburg.

Kansas City Rev. Sci. Ind. The Kansas City Review of Science and Industry. Karst Archiv. Karsten's Archives. Kent Nat. Hist Soc. Kent Natural History Society. Grand Rapids.

Math. Termiszet Kozlem. Mathematikai es Termeszettudomanyi KSzlem- Inyek, vonatkozolag a hazai vizonvokra. Budapest.

Mem. Geol. Sur. Memoirs of the Geological Survey of Great Britain.

Mem. Geol. Sur. Ind. Memoirs of the Geological Survey of India. Calcutta.

Metall. Rev. The Metallurgical Review, New York.

Min. Journ. Mining Journal. London.

Min. Mag. The Mineralogical Magazine and Journal of the Mineralogioal Society of Great Britain. London.

Min. Mitth. Mineralogische und petrographische Mittheilnngen. Vienna.

Mitth. nat. Ver. Maja. Mittheilungen dee naturforschenden Vereins Maja. Clausthal.

Nachricht. k. Ges. Wiss. Nach rich ten von der kSniglichen Gesellsohaft der "Wissenschaften und der Georg- August Universitfit. Gdttingen.

Nat. Hist. Phil. Soc. The Natural History and Philosophical Society.

Natl. Acad. Sci. National Academy of Science. Washington.

A ature. Nature, a weekly illustrated Journal of Science. London.

Neues Jahrb. fur Min. Neues Jahrbuch fur Mineralogie, Geologic und Palseontologie. Stuttgart.

A. Jahrb. Neues Jahrbuch fur Mineralogie, Geologie und Palseontologie. Stuttgart.

North Am. Rev. North American Review.

Nova Acta R. Soc. Upsal. Nova Acta Regis Sooietatis Upsalensis. Upsala.

N. Staff. Field Club. North Staffordshire Field Olub, Annual Addresses, etc. Hanley.

Nyt Mag. Nat. Nyt Magazin for Naturvidenskaberne. Christiania.

Oefvers. K. Vet.-Akad. Fbrhandl. Oefversigt af KongL Vetenskaps-Aka- demiene Forhandhngar. Stockholm.

Oesterr. Zeitsch. Berg- Hutl. Oesterreichische Zeitsohrift fur Berg- und Huttenwesen. Vienna.

Penn Geol. Sur. Pennsylvania Geological Survey. Harrisburg.

Phil. Mag. London, Edinburgh and Dublin Philosophical Magazine and Journal of Science. London. i —

Phil. Mag. and Annals of Phil. Philosophical Magazine and Annals of Philosophy. London.

Phil Trans. Philosophical Transactions of the Royal Society of London. London.

Poggend. Ann. PoggenddoriTs Annalen.

Iron Obes Of Minnesota. 261

Politecnieo. II Politecnieo. Gioraale dell' Ingegneria ed Archittetura Civile ed Industrials Milan.

Proc. Ac Nat. Set Phil Proceedings of the Academy of Natural Sciences. Philadelphia.

Proe. Am. Assoc. Adv. Sci. Proceedings of the American Association for the Advancement of Science. Salem.

Proe. Am. Phil Soc. Proceedings of the American Philosophical Society. Philadelphia.

Proc. Boat. Soc. Nat Hist Proceedings of the Boston Society of Natural History.

Proc Bristol Nat. Soc. Proceedings of the Bristol Naturalists' Society. London and Bristol

Proe. Cleveland Inst Eng. Proceedings of the Cleveland Institute of En- gineers. Middlesbrough.

Proe. Dudley OeoL Soc. Proceedings of the Dudley and Midland Geologi- cal and Scientific Society and Field Olub. Dudley.

Proc OeoL and Poly. Soc. of the West Riding. Proceedings of the Geo- logical and Polytechnic Society of the West Biding of Yorkshire. Leeds.

Proc OeoL Assoc. Proceedings of the Geologists' Association. London.

Proc. Inst Civ. Eng. Minutes of the Proceedings of the Institute of Civil Engineers. London.

Proc. Liverpool OeoL Soc. Abstract of the Proceedings of the Liverpool Geological Society. Liverpool.

Proc. Lye. Nat. Hist N. Y. Proceedings of the Lyceum of Natural History of the city of New York. New York.

Proc Roy. Dublin Soc. Scientific Proceedings of the Royal Dublin Society.

Proe. Roy. Soc N. S. Wales. Proceedings of the Royal Society of New 8outh Wales. Sydney.

Proc S. Wales Inst Eng. Proceedings of the South Wales Institute of En- gineers. Swansea.

Q. J. 0. S. The Quarterly Journal of the Geological Society of London. Quart. Journ. Qeol. Soc Ditto.

Quart. Journ. Set and Arts. Quarterly Journal of Science and Annals of Mining, Metallurgy* Engineering, Industrial Arts, Manufactures. London. Queenslander. The Queenslander. Folio. Brisbane.

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Rep. Brit Assoc. Report of the British Association for the Advancement rf Science. London.

Rep. Prog. Qeol Can. Report of Progress for , Geological and Nat-

ml History Survey of Canada. Montreal.

Rip. Run. Qeol. Com. Report of the Russian Geological Committee. St. -Petersburg.

Rev. Qiol Revue de Geologie (by Delesse and De Lapparent). Paris.

Rev. Min. Revista Mmera. Periodico Cientifioo e Industrial. Madrid.

Revista Miner a. Vid. Rev. Min. .

Rev, Sci. Revue Soientifique de la France et de lt ranger. 4to. Paris.

Rev. Univ. des Mines. Revue Universelle dee Mines, de la Mltallurgie, dea taux Publics, des Sciences et des Arts applique

Sch. Min. Quart. Columbia College School of Mines Quarterly. New York. Senate Dyes. D wum nits of the United States Senate. Sitx. k. . Qes. Wiss. Sitzungsbariohte der Edniglichen bohmisohen Vesellschaft der Wissenschaf ten . Prague.

Trans. Ac Sci. St. Louis. The Transactions of the Academy of Science of fit. Lrais.

ZVoiml Am. Inst. Min. Eng. Transactions of the American Institute of Jfining Engineers. New York.

Trans. Assoc Am. Qeol Nat. Transactions of the Association of American Otologists and Naturalists.

262 Bulletin No. Vi.

Trans. Canib. Phil. Soc Transactions of the Cambridge Philosophical Society. 4 to. Cambridge.

Trans. Chesterfield Inst. Eng. Chesterfield and Derbyshire Institute of Mining, Civil and Mechanical Engineers, Transactions. London and Derby.

Trans. Edin. Qeol. Soc. Transactions of the Edinburgh Geological Society. Edinburgh.

Trans. Manch. Qeol. Soc. Transactions of the Manchester Geological Soci- ety. Manchester.

Trans. N. Engl. Inst. Eng. North of England Institute of Mining and Me- chanical Engineers, Transactions. Newcastle-on-Tyne.

Trans. Nova Scot. Inst. Proceedings and Transactions of the Nova Scotian Institute of Natural Science. Halifax, N. S.

Trans. N. Y. Acad. Sci. Transactions of the New York Academy of Sci- ences. New York.

Trans. N. Zealand Inst. Transactions and Proceedings of the New Zealand Institute. Wellington.

Trans. Roy. Qeol. Soc Cornwall. Transactions of the Royal Geological Society of Cornwall. Penzance.

Trans. Roy. Soc. Can. Transactions of the Royal Society of Canada. 4to. Montreal.

Trans. Roy. Soc. Edinburgh. Transactions of the Royal Society of Edin- burgh. 4to. Edinburgh.

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Verh. k.-.k geoL Reichs. Yerhandlungen dee kaiserlich-kSniglichen geologischen Reich sanst alt. Vienna.

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tion of these beds is northeast and southwest, but when subject to local variations the course is north and south or north-northeast and south-soathwest. Sometimes, however, the ore occurs in large masses in the rock without any regular

Earallelism of the sides, as is the case in Essex county. And lastly, it is disseminated l particles in the rock, apparently without any connection with a bed or vein."

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"Becquerel considers that to a certain depth in the earth a multitude of electric cur- rents exist, with very different directions, the general result of which would produce an action on the magnetic needle. He considers these currents would be caused by the permanent communication kept up by means of numerous fissures through which the sea-waters percolate cither to the metals of the earths and alkalis or to metallic chlo- rides, causing the metals to take negative electricity, and the steam and other vapors positive electricity. One part of the latter electricity, he infers, would be carried into the atmosphere by volcanic eruptions, and the other would tend to combine with the negative electricity of the bases, by passing through all the conducting bodies which established the communication between the metals or their chlorides, and the solid, liquid or gaseous substances which filled the fissures. Hence, he observes, a number

tne interior or tne giooe, producing ppreciate the whole extent, but which is."

liquid or gj

of partial electrical currents would circulate in the interior of the globe, producinj

electro-chemical reactions, of which we cannot at

certainly would give rise to numerous compound

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Report on the country north of Lake Superior, between the Nipigon

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— . Report on an Exploration in 1875, between James Bay and Lakes Superior and Huron. Geol Sur. Can. Rep. Prog. 1876-77, pp. 294-342.

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. Mining in Canada in 1875. Iron, n. s. vol. viii, pp. 6, 41, 229. 1876.

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Bell, Will. ti. Mineral Lands of the Upper Mississippi. Executive Docs., 1st Seas. 28th Gong., 1843-44, hi., No. 43, 52 pp.

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Berber, Dr. Geological Tour in Devon and Cornwall. Geol. Trans., vol. i, ser. 1. 1811.

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. Jahrb. d. K. K. geol. Reichsanst. 1869, p. 367.

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Billings, E. W. Iron Ores of Canada. Can. Nat. and Qeol., vol. ii, 1857,

p. 20.

"The iron ores of this Province are chiefly confined to the Laurentian system of rooks, in which they occur in such prodigious quantities that this may be styled pre- eminently the iron formation. The origin of these ores we know not. It is only cer- tain that during the period when the Laurentian rocks were in process of being formed, iron was abundantly elaborated, while in the age of the Huron! an deposits copper was principally produced and iron not at all in any great quantity."

Birkinbine, John* [Cerro de Meroado Iron Ore Masa,Durango,Mexioo.1 Chicago Mining Journ vol. ii, p. 184, 1882.

. Iron Ores of Tennessee. Journ. U. S. AssocCharcoal Iron Work- ers, voL iv, No. 2, p. 82, 1883. Taken from the Hand-Book of Tennessee, pub- lished by the Bureau of Mines.

— — . Cerro de Meroado (Iron Mountain) at Durango, Mexico. Report to W. L. Helfenstein, President of the Iron Mountain Company of Durango, Mexico. Trans. Am. Inst. Min. Eng. 1884.

"I incline to the belief thac the Cerro de Mercado is formed of one or more immense veins or lenses of specular iron ore, standing nearly vertical, the fragments of which have, by the actions of the elements for ages, been thrown down to form the slopes of the mountain as a talus; but the extent of this de- bits! ore is too great to permit of locating any foot or hanging walls."

— — . The Iron Ores East of the Mississippi River. Mineral Resources of the U.S. 1886, p. 60.

r . The Gogebic Iron Range. Jour. U. 8. Assoc. Charcoal Iron

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Workers, vol. viii, No. 1, p. 86, 1888.

. Prominent Sources of the Iron Ore Supply of the United States.

from*. Am. Inst. Min. Eng. 1889. Abstract in Bull. Am. Iron and Steel Assoc, July It), 1889.

- Lake Cham plain Iron Region. Jour. U. S. Assoc. Charcoal Iron

Workers, vol. viii, No. 4, p. 218, 1889; vol viii, No. 6, p. 823.

The Flax-seed Ore of Wisconsin. Jour. U. S. Assoc. Charcoal Iron

Workers, vol. viii, No. 4, p. 244, 1889.

268 Bulletin No. Vi.

JBischof, Gustav. Ueber d. Entstehung d. Quarz- a Erzgftnge. Neues Jahrb. f. Mineral, 1844, p. 257.

Chemical and Physical Geology, vol i, pp. 155-157, 166-167, 236,

1847. Describes fully the process of the formation of iron ores by the action of decaying organic matter, essentially the same as advocated later by Hunt, Le Gonte, Newberry and others, who have extended the theory to iron ores of all ages.

Elements of Chemical and Physical Geology. Cavendish Society's

Publications, voLiii, 1853; pp 521, 543.

"Oxide of iron is in all instances the product of decomposition of ferruginous min- erals, and since almost all minerals constituting rocks contain some iron, it may origi- nate from the most diverse sources. The frequent occurrence of red and brown hematite in limestone, the transition of one into the other, and the presence of the same fossil remains in the iron ores as in the limestone, lead to the conclusion that many deposits of iron ore have originated by the displacement of the carbonate of lime. There is no doubt that the ores of iron and manganese have originated from the decomposition of silicates of these metals, for they always occur in rocks that are rich in such silicates. Weissenbach states, that near Johanngeorgenstadt. the hematite lodes generally follow the junction of the granite and mica schist, and they extend into the latter only as ferruginous clay and slate. There is no doubt that in this instance the iron ores originated from the mica schist that is so rich in silicates of iron and which is somewhat decomposed near the lodes. But the products of this de- composition are found separately in the lodes, the quartz being the first, and the brown hematite the second member. This separation may be easily accounted for, when it is remembered that the small amount of carbonic acid contained in water would be in the first instance consumed in effecting the decomposition of the silicates. The water thus deprived of its carbonic acid could not dissolve the carbonate of iron that had been produced, but it could exercise the same solvent action upon the silica that had been eliminated as water containing carbonic acid. Consequently it removed the silica and deposited it in the lode fissures. When the decomposition of the sili- cates of iron was so far advanced that carbonic acid was no longer consumed in this way, the carbonate of iron would be dissolved and carried into the lode, where, accord- ing as there was or was not access of atmospheric air, it would be deposited as hy- dra ted peroxide or as carbonate of iron."

Lehrbuch der Chemisohen und Physicalisohen Geologie, Bonn, 1854,

voL n, p. 1325.

" All iron ores in gangues or layers are either immediate deposits from water or are deposited from such by the removal of other substances. There Is no rock sediment in fact wholly free from protoxide of iron. Even in the variegated red sandstones I have found remarkable quantities. Plenty of material is at hand therefore, in the adjoining strata for even such vast beds as those of Schlettenbaoh and Bergzabern in Kheln- baiern. Should a rock contain nothing but peroxide, organic substances will reduce this to protoxide and the developing carbonic acid will convert this again into carbon- ate of iron. Never has an iron gangue been filled by sublimation. The sublimation of iron in Vesuvius is a local exhibition, impossible, as Mitscherlich showed (Poggend. Ann. B. xv, S. 630) without the help of water. Iron ores change into each other, but never into other minerals. All of them are products of the decomposition of iron-hold- ing minerals, and as scarcely any mineral is not iron-holding any mineral may form an iron ore bed. The oxide and especially the protoxide of iron are strong bases closely related to and easily with moderate heat uniting with silicic acid, as is seen in blast furnace processes, when, for instance, copper smelters add quartz min- erals to get a fluid slag from the protoxide of iron and silica, or when welders sprinkle fine sand on the end of the iron to be welded, to turn thereby the coating of the proto- peroxide into a silicate slag which every blow of the sledge removes ana lets the pure iron come face to face. See then from these examples how impossible it would Ite to find quartz and magnetic iron separate if they were of igneous origin. Yet at Arendal the ra- mifications of magnetic iron penetrated the syenite and granite walls, while bands and veins swarm along the bed-planes and cleavage lines of the gneiss. As little can the magnetic ore result from a metamorphosis of the gneiss plutonically. And if syenite ana granite were igneous rocks it were impossible for magnetic iron to separate from them. Wet segregation alone remains." (Lesley, Iron Mfrs. Guide.)

Blake, Wm. P. Iron Regions of Arizona. Am. Jour, Sci., ii, xl, 1865, p. 38a

. Report on Iron and Steel, Vienna International Exhibition, 1873.

Washington, 1876, pp. 310.

. Notes on the Occurrence of Siderite at Gay Head, tylass. Trans.

Amer. Inst. Min. Eng.f vol. iv, pp. 112, 113. 1876.

. Manufacture of Ferro Manganese in Austria. {Amer. Inst. Min.

Eng.) Iron, n. s. vol. vii, p. 551, 1876.

. Iron Ore Deposits of Southern Utah. Trans. Am. Inst. Min. Eng.,

xiv, p. 801, 1886.

Bleicber. . Le mineral de fer de Lorraine an point de vue stratigra-

Iron Ores Of Minnesota. 269

phique et palebntologique. Bull. Soc. Qeol. France sir. 3, t xii, pp. 46-107, 1884. Bull Soc. Sci. Nancy, ser. 2, t vi, 15 Ann. pp. xviii-xz 1883.

Boase, Dr. Henry* Contributions Toward a Knowledge of the Geology of Cornwall. Trans. Boy. Oeol. Soc. Cornwall. Ser. i, vol. iv, 1832, p. 166. Bead October, 1880 and 1831. Supports the theory that ore deposits in lode9 were formed at the same time with the rooks themselves; that the whole was a contemporaneous creation; and that there have been neither fissures subse- quent to the formation of the mass, nor filling up from above or below.

. Treatise on Primary Geology, 1834.

Boll, Jacob. Geological Examinations in Texas. Amer. Nat, vol. xiv, pp. 684-686, 1880.

Bonwtck, J. The Victorian Iron Mine. Irotf, vol. vii, p. 546, 1876.

Borlase, Rev. Win. Natural History of Cornwall, 1758.

Bovet, M. A. de. The Iron Ores and Iron Industry of Minas-Geraes, Brazil. Jour. U. S. Assoc. Charcoal Iron Workers, vol. v, No. 2, p. 58, 1884.

Bowron, W. M. The Practical Metallurgy of Titanic Iron Ores. Metal- lurgical Review (N. Y.), vol. ii, p. 309, 1877. Abstract in Proc. Inst. Civ. Eng. vol. lvi, pp. 355, 356, 187a Trans. Am. Inst. Min. Eng., xi, p. 159. 1882.

. The Geology and Mineral Resources of Sequatchee Valley, Ten- nessee. Trans. Am. Inst. Min. Eng., xiv, p. 172. 1885.

Boyd, C R. Resources of South-west Virginia, showing the mineral de- posits of iron. &c, p. 335; map and woodcuts. 8vo. London and New York, 1880-1881. Trans. Am. Inst. Min. Eng., v, p. 81; viii, 338.

Branns, D. [Ironstone of Ilsede, Peine.] Zeitsch. gesammt. Nat. n. s.Bd ix, p. 280, 1874.

Brit ton, Dr. N. L. Brown Hematite of Staten Island. Annals N. Y. Acad. Sci., vol ii, pp. 175-177.

Rro*dhead, Or. C. Missouri Ores of the Carboniferous Age. West. Rev. Sci. Ind., vol. 1, pp. 650-654, 1878.

Brninard, A. F. Hematite of Franklin County, Vermont. Trans. Am. Inst. Min. Eng., xiii, p. 689. 1884.

Broeffger, W. C, and H. H. Reusch. [Note6 on Elba.] Boll. R. Com Qeol. Ital., vii, pp. 223-227.

"The £. end and higher part of the island consist of older schists, in which are the lion-mines; though connected with augitic rock, it is held that the ores themselves are not of eruptive nature. The case is parallel with that of Arendahl."

Brooks, lbTaj- T. B. Qeol. Sur. Mich., I, pp. 1-319, II, pp. 298, 1873.

The soft hematites are thought to result, perhaps, from the decomposition of a "limonitio silicioue schist," with which they are associated. It is not at ill improbable that this change may have been brought about by the alkaline waters of former thermal springs.

— — . The Method and Cost of Mining- the Red Specular and Magnetic Ores of the Marquette Iron Region of Lake Superior. Trans. Amer. Inst. Min. Eng., vol. 1, pp. 193-203.

Brown, J. The Formation of Fissures and the Origin of their Min- eral Contents. Trans. Am. Inst. Min. Eng. 1874, ii. 215-29.

Brown, Charles B.. and J. G. Hawkins. Reports on the Physical, Descriptive, and Economic Geology of Guiana, pp. iv., 297. 8vo. London.

Browne, D. H. The Distribution of Phosphorus in the Ludington Mine, Iron Mountain, Michigan. Am. Jour. Sci., III., zzxvii, p. 299, 1889.

"The suggestion made by Mr. Ii. D. Irving, in the American Journal of Science for October, 1988. that the ore has been washed into its present position from previously precipitated beds of carbonate seems to me very plausible, and is borne out in a large measure by the chemistry of the ore body. I should, however, suggest this change, that the original deposits of Iron and lime were not as crystallized side rite and calclte, but at hydrous oxiae and carbonate of lime, with intermixed calcareous deposits.

270 Bulletin No Vi.

Brown, Thomas F. On the South Wales Coal-field. Proc. 8. Wales Inst. Eng. Vol. ix, pt. i, No. 2, &c. 1874.

Brush, Prof. Geo. Native Hydrates of Iron. Am. Journ. Set., (ii.) xliii., p. 219. 1867.

Brustlein, M. Sur les gisements de minerai de fer de la province de Norr- boten, Sue*de. Comptes Rendus Soc. Ind. Min. 1884, pp. 111-115, Translated with additions, from Stahl un I Eisen. 18 S4.

Burat, . Throne dee gites m£talliferes, 1845, p. 247. Geologie appliqule,

1858, p. 354. Annates £ Mines, 1852, vol. L, p. 608.

On Iron Ores of Elba:

''Burat thinks the iron-ore must here have penetrated upwards, precisely in the same manner as igneous-fluid rocks. This supposition, he thinks, solves the whole enigma of the origin, against which indeed many important doubts may be raised." Yon Cotta, Ore Deposits.

"Burat says of Rio la Marina, which was the only locality where iron was exploited in 1845; that this largest and richest iron deposit of the island, (of Elba), has penetrated, parallel to the stratification, between quartzose schist and limestone. .The centre of the same consists of crystalline specular iron and compact limonite: the former con- tains concretions of iron pyrites. The limits, towards the hanging and foot-walls, are rendered indistinct by intermixtures and transitions. The enclosing strata have also become very crystalline near the deposits, and contain amphibole and lievrite. All the relations tend to show a sublimation or eruption. When we call to mind that on Vesuvius newly formed fissures have been filled, in the course of a few weeks, with specular iron by sublimation; this manner of formation becomes very probable for the iron-deposits of Elba, although the island does not belong to the truly volcanic ones. The apparently massive occurrence of the specular iron can be probably traced baok to a repeated Assuring and penetration of these rocks.'* Von'Cotta, Ore Deposits, pp. 356, 357."

Burci, G. Berg. u. Huttenm. Zeitung. 1862.

Burt, Win. A., and Bela Hubbard. Reports on the Geography, To- pography and Geology of the (J. S. Surveys of the Mineral Region of the South Shore of Lake Superior for 1845, etc. In the "Mineral Region of Lake Super- ior," by J. Houghton, Jr. and T. W. Bristol, Detroit, 1846. Senate Docs., 1st Sees. 29th Gong., 1845-46, vii, Doc. 357, 29 pp.; 1st Sess. 31st Gong., 1849-50, iii,

Butlin, W. H. On the Northampton Iron Ore District. London Iron Trades Exchange, vol. xxxii, p. 641. 1883.

Cadell, Bf . H. On the Age and Origin of the Metallic Veins of the Upper Harz. Min. Mag., vol. vi, pp. 90-97, 1884.

Calvert, John. On the Decomposition of Rocks and the Reoomposition of their Metallic Constituents. Mining Mag., 1854, iii, 371-376.

Campbell, A. C The Copper and Iron-bearing Rocks of Lake Superior. Eng. Min. Journ., vol. xxxi, p. 20, 1881.

Campbell, . Iron Ore Deposits. Eng. Min. Journ., vol. xxx, p. 39,

Campbell. J. L. Geology and Mineral Resources of the James River Valley, Va. 8vo. New York. Pp. 119; map, 1883.

Carcanagues, M. £tude sur la Teneur en Fer et en Manganese dee Minerals de Rancid. [Arilge.] Ann. des Mines, vol. v, pp. 115-122, 1884.

' Carew, Richard. Survey of Cornwall, 1602. (Reprinted with a Life of the Author in 1769.)

Carne, Joseph. On the Relative Age of the Veins of Cornwall. Trans. Roy. Oeol. Soc. Cornwall, ser. i, vol ii, p. 49, 1822.

Caron, . Berioht tlber eine Instruotions-reise in Spanien. ZeiUehr.

Berg- , Hutt. Salinenw. Band xxviii, p. 105, 1880.

Contains geological literature of Spain, general geology of Spain, with a map and special descriptions of the mines.

Casteodyck, . Neues Jahrb. /. Mineral, 1853, p. 326. Ver-

handl. d. naturh. Vereins d. preuss. Rheinl. u. West/. 1853, p. 140.

Ibon Ores Of Minnesota. 271

Ihne, Berg- u. Huttenm Zeitung, 1862.

Centeno y Garcia* Jo£. [Geology and Mineralogy of the Philippine Islands.] Bol. Com. Map Oeol. hspan, t. iii, pp. 181-234, pi. B (map), 1876.

Chanconrtois, de. [The Question of Native Iron.] Bull. Soc. Qiol.

France, se>. a, t v, pp. 110, 111, 1877.

"Refers to the discovery of a bed of native nickelliferous iron in Brazil, and to the Ovlfak iron."

Chapman, E. J. Canadian Jour., 1860, (2) v, 1-19, 168-182, 517-531; 1861, Ti, 149-165, 425-455, 500-518; 1862, vii, 108-121; 1863, viii, 17-33, 111-127, 185- 216, 487-462; 1804, ix, 1-lt).

. An Outline -of the Geology of Ontario, based on a sub*

division of the Province into Six Natural Districts. Canad. Jour., 1875. (2,) $80-588; 1876, (2,) xv, 92-122.

. On some Deposits of Titaniferous Iron Ore in the counties of

Haliburton and Hastings, Ontario. Trans. Roy. Soc. Can. 1884. pp. 159, 160.

Charpentier, Joh. Fr. Wilb. Mineralogisohe Geographic der Kur- eachaiohen Lande. 4to. Leipzig. 1778.

Cheater, A. H. On the percentage of iron in certain ores. Trans, Am. Inst Min. Eng., 1875, iv, 219.

. The Iron Region of Northern Minnesota. Oeol. Nat. Hist 8ur.

Minn. 1882. xi, pp. 15&-167.

Chfmanovsky, M. (The Iron ore and Iron Mines of Kriwoy-Rog.] Ga- zette des Mines. No. 6, 1888. 'Considers the iron ore to occur here in a massive deposit."

Cohen, Dr. E. [Titanic Iron from the South African Diamond Fields.] #. Jahrb. Heft vii., pp. 695-697. 1877.

Colby, George D. Mineral and Metallurgical Resources of Northern Central New York. Jour. U. S. Assoc. Charcoallron Workers, vol. 6, No. 5, p. 262, 1885.

Collins. H. On Pawton Iron Mine. Rep. Miners' Assoc. Cornwall for 1875. pp. 26-30.

" Rod haematite and a little spathic iron occur in a true fissure-lode in the Killas, hearing N. 18° W. The author supposes the contents of the vein may have been de- rived from the enclosing rocks."

. On the Great Perran Iron Lode. Rep. Min. Assoc. Cornwall and

Devon, pp. 55-69. 1874.

Colquhoun, l>r, Hugh. Memoir on the Nature and History of the Argillaceous Carbonate of Iron. Phil. Mag. ( /) vol. vii, No. II. Oct. 1827. pp.

Comstock, Theo. B. First Annual Report Geological Survey of Texas

1889. pp. 847-360.

"Three different kinds of exposures (of hematites) may be made out as viewed with reference to their modes of origin. To these, for convenience, we may give names as follows: (1) Altered Magnetite*; (2) Concretumary Ore*; <3) Hematite Sandstone."

Cook, Geo. H. Geology of New Jersey, 1868. p. 61.

"The beds of iron ore are thought by mauy persons to be veins; and they are so called in all the regions where they are mined. This term has been applied to them by the English and German miners, who have worked true veins in their own countries, and are habituated to think that all metallic ores are of igneous origin, and have l>een forced Into the positions they now occupy, in a melted state. This theory is sustained by the high authority of Prof. II. D. Rogers. Dr. Kitchell and all his assistants, after thorough examination of the mines, were entirely settled in their conclusions that the magnetic ores of New Jersey were of sedimentary origin, and had been deposited in beds just as the gneiss and crystalline limestone had. This too is the view of most writers and geologists of the present day.

From the observations of the present survey no other conclusion can be reached, but that the magnetic iron ores,of this state, have originated from chemical or mechanical deposits* Just as our hematites and bog iron ores do now; and that they have after- wards been covered by strata of Hand, clay and carbonate of lime; that with these they have since been upheaved, pressed into folds, and under the influence of pressure and water, for an immense length of time, they have undergone chemical and mechanical Changes, which have brought them to their present condition. They occur both in the limestone and the gneiss; they are entirely conformable to the other rooks in stratifl-

272 Bulletin No. Vi.

cation; they contain laminae of gneiss, hornblende, &c, just as the rocks do. and at their edges they frequently pass from the ore to the rock by such insensible gradations that one cannot tell where the ore ends nnd the rock begins. Folds, offsets, etc., occur in the ores just as in the other rocks. The columnar structure of some of these ores has been thought to favor the theory of their igneous origin; but beds of sedimentary limestone have been seen which have the same structure."

"In short, everything in structure, position and attendant minerals, shows that the ore is in sedimentary beds, the same as the gneiss is. Disturbance since its orig- inal deposition has brought its beds on edge, and so far has made it like ore in veins; and having this resemblance its beds, by the common usage of the country, are called veins, and we may so use the word in this report. There is no difficulty in conceiving of the beds as having been formed by the deposition of the peroxide of iron, and hav- ing since lost enough oxygen to change them into magnetic oxides." il. c. p. 533.)

beds of magnetic iron-ore are in layers in the strata of gneiss or limestone. They are in long narrow belts, which are parallel to the general northeast and south- west strike of the azoic rocks. They have the appearance of having been thrown down as a chemical deposit along the Dorders of streams or slopes, perhaps sea-shores. Just as oxide of iron is now deposited from spring water when it is exposed to the air; just as bog iron-ore is now depositing in many places in southern New Jersey, or just as oxide of iron is depositing at the salt springs in New York and Pennsylvania. Such deposits are necessarily of limited extent. They do not spread out over a great area as deposits of sand or clay may, but are separated from the water in which the oxide of iron is dissolved by the action of air and the escape of carbonic acid, and as quietly precipitated along the banks of rivulets or the shores of larger bodies of water into which the springs enter." (op .cit. p. 331.)

Coquawl, . Bulletin de la Soc.giol. de France, 184849; vol. vi, p. 340.

On French Iron Ore Deposits.

Cordel'a, A. Berg, und huttenm. Zeit. p. 21, 1858. On Iron Ore De- posits near Schmiedeberg.

. [Geology and Mineralogy of Greece.] Pp. 188, 8vo, Paris. 1877.

Corneliussen, O. [Deposits of Haematite at Noeverhaugen, Norway.] Nyt. Mag. Not. Bd. 22, p. 878, Map. 1877.

'4A geological and physical description of the iron ore deposits discovered in 1874 not far from Bodo. The ore occurs in and between layers of mica schist and granular limestone of primitive age. Holds that the ore does not occur as layers, but owes its origin to plutonic forces, perhaps a process of sublimation— an opinion contrary to that of Gumoeltus." (Geol. Record.)

Cornet, F. L. Catalogue Special del 'Industrie Mine'rale Beige d l'Expo- sition Universelle de 1878. La Belgique mine rale. [Mineral department of the Belgian exhibits at the 1878 Exhibition.]

Coste, Eugrene. Report on the Mining and Mineral Statistics of Canada for the year 1887. Geol. Soc. Can. Annual Report, Vol. Ill, part II, new series, pp. 110, 1W88.

"It is only natural that we should conclude, like many other geologists have done before in those countries (New York. New Jersey. Norway and Sweden), that the iron ore and phosphate to be found in our Archzean rocks are the result of emanations which have accompanied or immediately followed the intrusions through these rocks of many varied kinds of igneous rocks which are, no doubt, the equivalent of the vol- canic rocks.

Curtis, W. M. The North Shore of Lake Superior as a Mineral-bearing District. Trans. Am. Inst. Min. Eng., 1877; v, 473 487.

Credner, Hermann. Geogn. Verh. Thur. u des Harzee. 1843. P. 127.

. On the Iron Ore Deposits of the Upper Peninsula of Michigan.

Zeitschr. d. d. Geolog. Gesells., 1865, vol. xvii, pp. 208, 228; 1866, p. 83; 1869, vol. xxi, pp. 516, Berg. u. Hut. Zeit. 1866, p. 29; 1871, p. 36a Zeitschr. f. d. Saturwi&sensch.i 1870, vol. 35, p. 20.

Crosby. W. O . On a possible origin of petrosilioeous rocks. Proc. Bast. Soc. Xat. Hist, vol xx, pp 160-170, March, 1879.

He considers the iron ores and associated siliceous strata to have been slowly deposited in abyssal depths of the ocean and to have been modified by segre- gation since their first accumulation.

Cross, Rev. J. K. The Geology of Northwest Lincolnshire. Qu<tri. Journ. Geol. Soc vol. xxxi, pp. 115-130, 187&.

Cunningham, Walter. Report as Mineral 4gent on Lake Superior. Jan. 8, 1845. Senate Doc*. 28th Cong., 2d Seea 1844-45, vii, No. 98, 5 pp. j

Czvszkowsk*, S. Exploration geologique et induatrielle des regions fer- riferfe de Tile d'Elbe (Italic. Sva Atais. Pp. 87,1882.

Iron Ores Of Minnesota. 273

. [Geology of the Iron District of Canigou, E. Pyrenees.] Pp. 31,

folding map, 8vo, 1879. Paris and Alois.

% [Geology of the Iron District of Bilbao-Somorrostio, Spain.] Pp

40, folding maps, 8vo. Paris, 1879.

. Lee Minerals de Fer dans 1' Icoroe terrestre. Bull. Soc. Ind. Min.

St. Etienne, sir. 2, t. xiii, and separately issued, pp. 222, with atlas, 1881.

Daddow, S. H. and Benjamin Bannan. Goal, Iron and Oil, or The Practical American Miner, 1866.

"We may refer most of our great Azoic beds of magnetic and specular ores and red oxides of iron to this (volcanic eruption) cause, and their formation to the same agencies.'*

Danish, T., and R. Howse. Some Remarks on the Beds of Ironstone occurring in Lincolnshire. Trans. N. Engl. Inst Eng., voL zxiv, pt. 1, pp. 23- 33, 4 plates, 1875.

Damour, A. [Metallic Iron from Santa Oatarina, Brazil.] Compt. Rend, t. lxxxiv, p. 478, 1887.

Dana, James I>. Note on the Azoic Age and metamorphic origin of the Iron Ore of Mexico, described on p. 309 of American Journal Science, vol- ume xxxix, ser. 2. Am. Jour. Sci., h, xxxix, 1865, p. 358.

Manual of Geology, pp. 231, 155. 1874.

The beds of argillaceous iron-ore (Upper Silurian) which spread so widely through New York and some of the other states west and south, could not have been formed in an open ea; for clayey iron-deposits do not accumulate under such circumstances. They are proof of extensive marshes and therefore, of land near the sea-level. The fragments of Orinolds and shells found in these beds are evidence that they were, in part at least, salt-water marshes, and that the tide sometimes reached them.'*

In reference to the Lauren tian he states:

"Limestone strata occurred among the- alternations, and argillaceous iron-ores though vastly more extensive. The argillaceous iron-ore has become the bright hematite or magnetite, and it is banded by, or alternates with, schist and quartz, etc.. which were once accompanying clay and sand-layers."

Am. Jour. Set., iii, ix, 223, 1875.

In a review of the "Geology of New Hampshire," Part I., says: "The existence of great beds of iron ore in pre-Silurian te mines is regarded as evi- dence (in this following Prof. T. 8 terry Hunt) of the existence during the era of abund- ant regetation— on the ground that, in making marsh-beds of iron ore, the oxide of iron, when carried in by the waters, is in the state of iron-salts of organic acids. But the era was a very long one; Helmholtz made the time which elapsed during the cool- lag from 2.000 deg. C. to 200 deg .mouo.000 of years; and many more millions should be added for the continuation of the cooling down to 100 all of which necessarily antedated the first appearance of the simplest forms of life; and still more to reduce the temperature to 38 deg. U. (100° F.), which limit was probably reached before the dote of the Archaean. And in that long era, even to its close, the atmosphere certainly contained a greatly larger proportion of carbonic acid than now, if not also other telds; and also for this reason, it had much greater density. Hence carbonic acid, Which does now some of the work of iron- transportation, may have done far more then. It is surely very unsafe to conclude from the existence of those iron ore beds that the regetation was extremely abundant. or that any then existed."

Amer. Jour. Sci Aug. 1877, p. 132.

Amer. Jour. ScL (iii) xxii, pp. 320, 402, 1881.

Berkshire Geology, 1886, pp. 25. Berkshire Hist, and Sci. Soc.

"All now admit that the dimonite) oro is a secondary product : that is, that it was formed through the oxidation of iron that originally made part of minerals in the ohist, or In tho limestone, or else in both. My own conclusion is that the iron has come mainly from limestono formation and not from the schist or slate. Some of the limestone, as well as schist.con tains pyrlte, (or iron pyrites) a brass-colored aloeral consisting of 46.7 per cent of iron and !KI.:s of sulphur. But we are sure that this s) not the source of the Iron of these beds, because there is ordinarily very little pyrito Dresentln either tho schist or limestone; and secondly, because the oro Is peculiarly free from sulphur. How did the Iron get into the limestone? Why is it In that partof the limestone which is within a hundred yards of the schist? Why is It distribu- ted with so neat irregularity, here in broad patches, there in winding courses, abruptly widening or narrowing, and so on?

"If/ou accept of the view that the limestone was first made In great horizontal beds In the pure waters of a Lower Silurian sea; that the schist or slate was originally the sediment that in the following era was deposited over the limestone; that during the epoch of transition between the two conditions groat sca-l>order marshes Might hare existed, receiving, here and there, like similar modern marshes, iron-bear-

274 Bulletin No. Vi.

lng solutions through the drainage of a bordering country, until ore-deposits were made, you may perhaps put together a theory that will account for the introduction and the peculiar irregular distribution of the ore in the limestone."

Daniels, Prof. Edward. Annual Report of the State Geologist of Wisconsin for 1857, 62 pp. Madison, 1858. Iron ores of Wisconsin ooour:

"1st. In place as beds or veins in the rooks where they were originally formed or introduced,"

"2d. Deposited from aqueous solutions in low ground, as bog ore or ochre.*'

Danton , D. Sur la Geologic et les Minerals de fer de F Anjon. Bull. Soc. Ind. Min. St Etienne, t, x, pp. 597-637, 1881.

Dathe, E. Neues Jahrb. f. Mineral, 1876, p. 226.

Daubree, M. — Observations sur 1' original dee filons titaniferes dee Alpes. Ann. Mines, vol. xvi, 1849, p. 129; Geologie Experimental, p. 37.

Daubree, A. Compt. rend., xxiv, 1543-1550. Abstract in Canad. Nat, n.

e. vol. vii, 1875, p. 52.

In reference to the masses of native iron discovered in Greenland by Nord-

enskiold in 1870:

"The author is inclined to think that these masses of iron are not of meteoric origin, but that they have been formed from basaltic rooks and erupted from exceptionally great depths. These basaltic rocks frequently contain as much as 20 per cent, of ferric oxide, and it is not impossible that during their passage to the surface this oxide may have been partially reduced to the metallic state."

Daubree, Prof. [Internal Structure of Native Iron from OvifakJ Compt Rend., t lxxxiv, p. 66, 1877.

Daubree, A. [Report on Smith's Memoir on the Basalt with Native Iron of Greenland.] Compt Rend., t. lxxxvii, 1879.

Daubree , C . [Iron-bearing Books of Greenland.] BulL Soc. Q4ol. France, ser, 3, t. v, pp. 111-118. 1877.

Thinks it probable that theiron,likeits basaltic matrix, is of terrestrial origin. (Geol. Record, 1879.)

Daubree, Prof. [Recent Formation of Iron-pyrites in Thermal Springs and in Sea-water.] Compt Rend., t. lxxxi, pp. 851-859, 1875.

Davies, I>. C. Metalliferous Minerals and Mining. London, Oroaby, Lockwood & Co., 1880, pp. 274, 275. Very erroneous, according to Wadsworth.

, Sketch of the Metalliferous Deposits of Flintshire and Denbigh-

shire, Wales. Eng. Min. Journ., vol. xxxvi, pp. 382-385, 397, 398. 1883.

Davis, O. W. Jr. The Iron Ores of Maine. Jour. U.S. Assoc. Char- coal Iron Workers, vol. 7, No. 2, p. 66, 1886.

MI"The measures in the vicinity of the Katahdin Iron works are Silurian clay slates, which run like most of the rocks in this part of the 8tate, slightly north-east by south-

bv the waters of mineral springs that came up through the pyrites and deposited the iron on the sides of the mountain. The ore is all found on the sides and summit of an elevation that is from 900 to 400 feet above the level of the river. When the surface deDosits became exhausted it was found that extensive deposits existed at various deDths below the surface that were the product of oxidation of the ledge in situ occurring to the depth of 10 to 30 feet. These are sources of the present supply of the furnace, and appear to bo inexhaustible,"

Davis, Rev. . Native Iron in Liberia, South Africa. Annual of Scien- tific Discovery, 1856, p. 304.

Davis, R. H. The Mineral Wealth of Harrogate. Proc. Yorksh. Geol. Soc. vol. viii, pp. 357-366, 1884.

Davy, Ii. P. [Geology of the Segre District (Maine et Loire), especially of the Ironstone Beds.] Bull. Soc. Ind. Min. St Etienne, se> 2, t. ix, pp. 537, 635, 1880.

c Dawsoo, Geo. M". The Iron Ores of British Columbia. Jour. U.S. Assoc. Charcoal Iron Workers, vol. 8, No. 4, p. 233, 1889. Taken from Mineral Wealth of British Columbia.

Iron Ores Of Minnesota. 275

Dawson, J. W. On the Geologioal Structure and Mineral Deposits of the Promontory of Maimanse, L. Sup. Canad. Nat, and OeoL, 1857; li, 1-12.

— — . Can, Nat. n. s., vol. vii, p. 129.

. On the Geological Relations of the Iron Ores of Nova Sootia. Proc

Amer Assoc., vol. xxii B., pp. 138-146, 1873.

Describee iron ores as occurring in the two forms of beds and veins. He mentions veins of hematite, limonite and magnetite, and thinks they are con- tact veins exoept where they occur in Triassic trap.

Acadian Geology, pp. 588, 589; 187a

Considers the various iron ore deposits which he describes in Nova Scotia to exist as veins, filled by molten or sublimed material. He describes in detail the outcrops and enclosing rooks of a large vein in Londonderry, on the south- ern slope of the Cob*quid Hills, concluding as follows:

"The geological history of this deposit embraces the following occurrences: 1st. The formation of a wide, irregular Assure along a pre at part of the length of the Oobe-

auld mountains. 2nd. The filling of this fissure with a molten or softened, and par- ally even sublimed mass of ferruginous and calcareous matter, presenting,as I think, an evident illustration of the igneous formation of a vein of calcareous magnesian and ferruginous carbonates. 3d. The breaking up of the vein thus formed by cross- fractures and faults. 4th. The partial roasting of Its contents by heat, ho as to pro- duce the red ores, which are obviously the result of the heating and oxidation of a part of the carbonate of iron, and this process may be seen on minutely ex- amining the vein, to have extended itself from the walls of the smallest fissures. 5th. The action of heated waters passing through Its crevices and depositing sulphate of barytes and brown hematite. Oth. The influence of the air and surface waters in changing large portions of the superficial contents of the vein into ochrcy hydrous peroxide of iron. It is, however, to be observed thai this deposit may be accounted for on the supposition that a bed of iron ore and carbonate of lime and magnesia, similar to those occurring elsewhere in the upper Silurian, h:id been so softened and altered by beat as to penetrate in vein-like forms the surrounding rocks. Sir W. E. Logan has shown that phenomena of this kind occur in the La u rent Ian regions of Canada.

Veins of iron ores, similar in character to those above described, occur in nearly every part of this metamorphic district: they are, however of small magnitude, and 1 am pot aware that they are in any place of workable dimensions. In many places ex- tensive masses of shattered quartzite and slate are penetrated In every direction by lender veins of micaceous specular ore.

In addition to these veins of Iron ore, conformable beds, as already mentioned, exist In the upper Silurian slates, more especially on the Ea<t River of IMctou, at the local- ity indicated on the map. At this place one bed appears to be forty feet thick, and much resembles that in the Devonian at Nlctaux, but the ore is more siliclous and con- tains only about forty per cent, of metal."

Dawson. S. J. Reports on the exploration of the Country between Lake Superior and the Red River Settlement, etc. S. J. Dawson and H, Y. Hind, Toronto, 1858, 1859.

Day, St. John V. The Iron and Steel Industries of Scotland. In Notices of Some of the Principal Manufactures of the West of Scotland. 8vo. Glasgow, pp. 60. 1876.

Deby, Julten. Report on the Progress of the Iron and Steel Industries in Foreign Countries. Journ. Iron Steel Inst, pp. 213-302, pi. i, and pp. 1-213, ptii. 1877.

Do Castro, Manuel Fernandez. On the Influence which a molecular movement due to electricity may have exerted in certain geological phenomena, namely, the metamorphismof rocks and the formation of metalliferous deposits. Extract from a pamphlet; D.scursos leidos ante la Real Academia deCiencias, eta, en la reception publica del Exmo, Sr. Don Manuel Ferdandez de Castro, Madrid, 1878.

"Electro-telluric actions m:iv have played an Important part In the formation of the imlnsof oxldeof iron in the Tertiary: the oolitic iroii-oiv in the Jurassic deposit-s; the Hphero-slderlte of the Carboniferous formation and the tfeodlr iron-ore of the modern formation."

Deehen. H. von. IjeonhartVs Jahrlmch, 1851, p. 210. Entirely excludes the igueoaa-nuid injection theory; adopts that of infiltrations from below.

, Ironstone and Pyrites of the Zoche Schwelm. Verh. not. Ver.

preuss. Rheinl. Jabrg. xxxi, Sitz. pp. 103-113. 1874.

Dr. Report of the American Magnotic Iron Company, 1857. In speaking of the Theall vein near Croton Falls, N. Y., says, (Iron Manfr's Guide, p. 407):

276 Bulletin No. Vi.

"In conclusion, I would note that In applying the term 'bed or deposit* to this ore, I allude to its present aspect as qualifying the expression; but when the walls are reached on either side, its characteristic features as a vein will fully develop them- selves, for there is no doubt whatever that these iron accumulations are true veins, and are thus connected with larger masses below of an unknown width and depth."

Deicke , J. C. Berg, u Huttenm. Zeitung. p. 339. 1858.

De La Beche, Henry T. Report on the Geology of North Cornwall, Devon and West Somerset, pp. xxii, 648, maps, etc., London, 1839.

On the subject of the filling of veins by electro-chemical action Mr. De La Beche says on p. 372;

'The whole of the evidence, both of successive coatings of different substances in veins where the fissures seem always to have retained the same width, and of the coatings and different modifications of the contained mineral substances in those veins which have suffered successive dislocations, goes to prove that chemical or electro- chemical conditions in the lodes have varied materially at different times, producing a corresponding variety in the arrangement and number of the various mineral sub- stances contained in them, and causing aggregations of similar matter in some places and repulsion of different matter in others."

. On the Formation of the Bocks of South Wales and Southwestern

England. Mem. Oeol. Sur. Great Britain. Vol. 1., 1846.

On page 185 is discussed the origin of clay ironstone: "Mr. Hunt (keeper of Mining Eecords in the Museum of Economic Geology) having instituted a series of experi- ments to illustrate the production of these clay or argillaceous ironstones,found that de- composing vegetable matter prevented the further oxidation of the proto-salts of iron, and converted the per-oxide into the protoxide of iron by taking a portion of its iron to form carbonic acid. Under the conditions necessary for the production of coal dis- tributed among the associated sand, silt, and mud, the decomposition of vegetable matter would necessarily form carbouic acid among the products. This carbonic acid mixed with the water would spread with it over areas of different dimensions accord- ing to circumstances,forming salts and meeting with the protoxide of iron in solution, it would unite with the protoxide and form a carbonate of iron. The carbonate of iron in solution would mingle with any fine detritus which might be held in mechanical sus- pension in the same water, and hence when the conditions for its deposit arose, which would happen when the needful excess of carbonic acid was removed, the carbonate of iron would bo thrown down mingled with the mud. Under such conditions it would resemble carbonate of iron mixed with mud, and both would alike form impure Ijeds either of carbonate of iron or of lime, as the case may be, according as the matter de- posited from solution exceeded that thrown down from mechanical suspension. Both would also form nodules, in the usual manner,occurringin planes amid the mud where the carbonates were insufficient to constitute continuous beds."

Delafield, Joseph. Notice of new Localities of simple minerals along the north coast of lake Superior, etc. Ann, Lye. Nat. Hist, 1824, i, 79-81.

Delesse, A. Mines deFer des £lats-Unis. Annates des Mines, 1857, (5.) xii, 805-841.

Delius, C. T. Abhandlung von den Ursprtinge der Gebirge. Leipzig.

De Luc, J. A. Geological Travels. 3 vols. 1811. Mines of Cornwall, Devon and Somerset are described.

De Ranee, C. TO. On the Iron and Lead measures of Tynehead, Alston. Rep. Brit. Assoc, for 1882, p 531. 1883.

. On the Occurrence of Manganese and Hsematite at Nant Uohaf

near Abergele, Denbighshire, in Old Bed Sandstone or Carboniferous Basement beds. Coll. Guard, vol. xliv, p. 895, 1882. Trans. Manch. GeoL Soc., vol. xvii. pp. 47-56, 1883.

Derby, Orville A. Am. Jour. Sci. (iii) xxiii, p. 373, May, 1882.

Descostils, M. Collet. Chemical Observations upon Spathic Iron. Bead at the class of the Sciences in the French National Institute, Jan. 6, 1806. Jour, des Mines, vol. xviii, 1806. Annates de Chimie, lxxxiv, 188, 1812.

Devereux, W. B. Notes on Iron-ore Deposits in Pitkin County, Colo- rado. Trans. Amer. Inst. Min. Eng., vol. xii, pp. 638-641, 1884.

Dewey, Prof. Ch ester. Ores of Iron and Manganese in Bennington Vt. Silliman's Journal, vol. v, p. 250, 1822.

'" . A Sketch of the Geology and Mineralogy of the western part of

Massachusetts. Sillimanys Journal, vol. viii, 1824, p. 30.

Dewey* F. P. Some Canadian Iron-ores. Trans. Amer. Inst Min, Bng.

Iron Ores Of Minnesota. 277

vol. xii, pp. 192-204, 1884 Jour. U. S. Assoc. Charcoal Iron Workers, vol. v, No. 2, p. 67, 1884.

The Rioh-Hill Iron Ores. Trans, Amer. Inst Min. Eng, vol. x,

pp. 77-80, 1882.

Dieulafait, L. Revue Universelle des Nines, vol. vii, 1880.

L'origine et la Formation des Minerals Me" talli feres. Rev. 8ci. t.

[i, pp. 609-618, 1883.

D'Invilliers, E. V., and Lesley, J. P. Report on the Cornwall Iron Ore Mines. See Lesley, J. P. Trans. Am. Inst. Min. Eng. vol. xiv, p. 873,

D'Invilliers, "E. V. The Magnetic Iron Ores. Rep. Prog. Penn. OeoL

Survey. D 8, vol. ii, pp. 237-352, 1883.

"The magnetic ore bods of the South Mountains are regularly intrntt ratified with tfw gneim beds, and are evidently original sediments of limited extent, lens-shaped, swelli- ng at the center, and tapering to an edge, both side wise and downwards."

. Iron industry and iron ores of Berks Co., Pa. Second Oeol. Sur.

Penn., D 3, Part 1. 1883. Harrisburg.

. and A. S. McCreath. Comparison of some Southern Cokes and

Iron Ores. Trans. Am. Inst. Min. Eng. vol. xv, p. 731, 1887.

Distil rn ell, John. The Great Lakes or Inland Seas of America.' New York, 1863, 192 pp. and map.

Divers, E. On the Chrome Iron Ore of Japan. Chem. News, vol. xliv, p. 217; and Rep. Brit. Assoc, for 1881, pp. 587-589. 1882.

Dobrynkin, X. [Mineral wealth of the district of Mourom.] Gazette du gouv. de Wladinue, bos. 1-8, 1887.

Dolinsky, A., Ckimanovsky, M. and Jassinsky, B. [Lignite and iron ore in the provinces of Podolie and Wolynie.] Gazette des mines de la Russie meridionale, No. 110-141, pp. 1887-189*. 1886.

Dolinsky, L. [Statistics for 1885 and 1886 of the Mining Region of the Southwest (of Russia).] Journ. d. mines russes. No. 12, pp. 485-501, 1887.

Don ay re, F. M. [Geology, &c, of the S. E. of Almeria. Bol. Com. Map Oeol Espan, t. iv, p. 385. 1877.

Dove, George, Jr. The Frodingham Iron Field, North Lincolnshire. Journ. Iron Steel Inst., pp. 318-341, 1876.

Drown, J. M"., and Skinner, P. W. The Analysis of Iron Ores Con- taining both Phosphoric and Titanic Acids. Trans. Am. Iiwt. Min. Eng., vol. x, pp. 137-144. Am. Chem. Journ., vol. ivf pp. 1-7, 1882.

Duf renoy, M. Mernoire sur la Position des Mines de Fer de la Partie orientate des Pyrcae m, 1831. In tlite memoir '"Mr, Dufrenoy lias recently shown th:it the mines of M;emutite and Spathic, iron in

the Eastern Pyrenees. whieli ur In limestones of three aires, refenibl** severally

to the Transition Series, to the Lias and in the Chalk, are all situated in parts where theac Limestones are in near eontnet with the (ir:iiihi>; and he considers thai they have all most probably been filled by the Mihlimulion of mineral matter into cavities of the limestones, at. or soon after the time of 1 he elev;it inn uf tin' (iranite of this part of the Pyrenees." Itiiekland's (Jeolury and Miner;ilo:;v. liridewater Treatise, vol. if p. 508. 1858.

Du Noyer. Geology of Tsland Maee. Nat. Hist, and Phil. Soc, Belfast, Nov. 1862.

Tried to demonstrate that the iron ore in the basalt uf 11m- Matree ,4a*. true an aqueoua conglomerate as If it had been found in the In-art uf the old Ked Sand- stone."

Dnroelier, . Compt. ren'ln.v<*\. xxviii, p. (>i)7; vol. xiii, p. H")0, 1849.

Considered lodes to be formed by in tilt rations, sublimations and igneous-fluid injections.

ISamea, Henry H. Geological ReeonnoiHsnnoe of the Northern, Middle nd other Counties of Minnesota. St. Paul, 1HG0, 58 pp.

278 Bulletin No. Vi.

. Report of the State Geologist, on the Metalliferous Region Bor- dering on Lake Superior. St. Paul, 1866, 23 pp.

Eaton, Amos. An Index to the Geology of the Northern States. Boston*

"To counterbalance the lightness of the exterior crust. the interior of the earth must consist principally or wholly, of met illic or other very heavy substances, agreeable to our theory of successive deposits. It probably consists of several concentric layers of metals, of different specific gravities, arranged like the coats of our onion."

Egleston, Thonias. Boracio Acid in Lake Superior Iron Ores. Trans. Am. Inst Min. Eng., 1876, v, 131, 132.

Ekrenberg", . Proceedings of the Royal Academy of Science, Berlin,

1844, 1845. Abstract of his papers in Quart. Journ. GeoL Soc. LoncL, Aug. 1846. Vid. also Taylor's Scientific Memoirs, vol. i, pt. iii, p. 402.

Ells, R. W. Iron Ore Deposits of Carleton County, New Brunswick, Geological Survey of Canada. Report of Progress for 1874-5, pp. 97-104, map, 1876. Describes certain red hematite deposits in the Cambro- Silurian slates of Carleton County, N. B.

Emmons, Dr. Ebenezer. Fourth Annual Report of the Survey of the Second Geological District of New York. 1840. p. 276. Assembly Docs, No.

. Natural History of New York, Part IV. Geology, Pt. ii., 1842. p. 97.

"Origin of the Magnetic and Specular Oxides of Iron. I have had occasion so frequently to refer to igneous action, in my remarks upon unstratified and subordinate rocks, that I have already anticipated the views which I am about to present of these two oxides. It will be seen from the structure of the diagram, and from the general bearing of the facts, that such an origin is by far the most probable, though there are many geologists who maintain the theory of electro-magnetic agency; and it must be confessed that it possesses many plausible points, and a few facts which lend it some support. Still, as regards its establishment, it appears from the researches of Faraday, that we should be obliged to sustain it on the assumption that the materials must have been in a liquid state at the time of their formation; and as the principle of electro-magnetism has no power to act upon a substance, so as to transfer it from one point to another, if it is in a solid or aeriform state. Electro-magnetism, though it decomposes water, is unable to act upon ice. or to decompose any other substance when solid; this at least is the case in the experimental researchesof the most eminent philosophers of the day, in relation to the decomposing and transferring power of this agent.

"The igneous origin of both oxides rests partly, as already stated, upon the establish- ment of the plutonic character of the rocks associated with them, and partly upon the mode of their occurrence in those masses. It is true, that the specular oxide appears among the lower layers of a sedimentary rock; but a careful inspection will satisfy most observers that it appears here as an intrusive rock, and that it has been forced into this position subsequent to the deposition of this sandstone; the evidence of which appears in the facts which have been stated in the preceding pages, viz: its fractured and upraised condition. And it is not at all remarkable that a porous sandstone should have been penetrated by this material, so. as to appear somewhat homogeneous, when we consider the forces which must have acted previous to, and during its upheaval.

"I have noticed also, and it is a fact which has the same bearing as the others al- ready stated, that some portions of the rock adjacent to the ore are porous, or some- what vesicular; the pores are, however, quite small, but still they are quite charac- teristic, and are clearly different from that kind of porosity which arises from decom- position; they appear, in a word, like those in the sandstone of Connecticut river, in the vicinity of the greenstone trap. Of the origin, then, of the oxides of iron, there are a variety of facts of the same character, which, when observed in other rocks have been considered demonstrative of an igneous origin; if, then, we are not in error in rela- tion to principles already conceived, we can scarcely refuse to apply them, to the question of the origin of the ores of iron."

. Topography, Geology and Mineral Resources of the State of New

York. Pub Hshed in a Gazetteer of the State of New York. Albany, 1842.

. American Geology, Albany. 1855. pp. 139-155.

Geology of North Carolina, 1856, p. 84.

In that State "the oxides of iron occur only in veins excepting where the mass has undergone certain changes. The mode in which ferruginous veins have been filled is clearly that which is assigned to trap or granite. Iron, however, in combination with chlorine is volatile, and is vaporized and finally deposited in the condition of a per- oxide or specular oxide."

Emmons, 8. P. Trans. Am. Inst Min. Eng., vol. Ill, pp. 419-420. 1875.

"Prom the decomposition and oxidation of these various minerals, whether sulphu- rets or carbonates, hydrous peroxides will result, and hence we should expect to find them whenever these decayed rocks have escaped erosion."

Iron Ores Of Minnesota. 279

. Genesis of Certain Ore-Deposits. Trans. Am. Inst. Min. Eng., xv,

p. 137. 1887.

. Structural Relations of Ore-Deposits. Trans. Am. Inst Min. Eng. Boston meeting, 1888, pp. 36.

Eschwege, — v. Beitroge znr Gebirgskunde Brasiliens, 1832, p. 141; Pinto Brasiliensis, 1838, p. 225.

Fabre, G. [Siderolitio Deposits of Lozere.] Bull. Soc. Giol. France, 3

se>. t Hi, pp. 683-591. 1876.

"The Jurassic limestones are cut through and pierced by many veins and pipes of "eruptive" elays and granitic sands. Limonite, associated generally with oxide of manganese, occurs in these veins, the sides of which are corroded. These deposits occur also occasionally in sheets at the mouths of the veins, whence the belief that they have been ejected. The principal direction of the veins and pipes is N. N. W. All these accumulations are referred to geyserlan action towards the close of the Eocene period."

Fablerantz, A. 13. [Iron-ore District at Dannemora, Sweden.] Bihang. k. Svenska Vet.—Akad. Handl. Bd. 4, No. 2, pp. 1-15, 6 plates. 1877.

Faller, G. Berg- u. Hiittenm, Jahrb. d. k. k. . Bergacadem. 1867. Bd. xvii, p. 132.

Feist mantel, K. [The Ironstone of Subdivision D,of the Bohemian Silu- rian.] Sitz. k. bohm. Ges. Wiss. May, 1878.

Felkner, J. [Goal and Iron in Russia.] Pp. 174, 1 map. St Petersburg.

Featenberg-Packlsch, U. v. Der metallische Bergbau Niedersohlesiens etc., 8vo, Vienna. Pp. 117; map. 1880-81.

Firket, A. [Manganese-iron Bed of Moet-Fontaine.] Ann. Soe.G6ol.Belg. t v, pp. 33-41. 1878.

"The bed at a depth from the surface, consists of carbonate of iron and carbonate of manganese in about equal parts; at the outcrop it shows two divisions, one rich in ox- Ides of Iron and manganese, the other of schist and quartz-slate, passing! n to grits and poor In metals. The oxides are the result of atmospheric alteration. The bed is not a vein, but of the same ago as the U. Silurian rocks with which it is associated." Geol. Record, 1878.

. [Metalliferous deposits of the Landenne Mine, and the Silurian

Fault of Champ d'Oiseaux.J Ball. Ac. Boy. Belg. scr .2, t. 45. pp. 618-645,

folding plate, 1878.

"1. On the Silurian Fault and lodes of champ d'Oiseaux (Landenne sur Mouse). 2. Structure and lie of the Haematite beds. .1. Kpigenic change of oolitic haematite into siderite in contact with a vein of pyrites. 4. On the relation between this phenome- non and the metalliferous iutllllnir of the lodes of the Landenne mine. Concludes that the water to which he attributes the metal 11 ferous deposit was charged with carbonic old. To the action of the last is due the enlargement of the fissures in the Carbonifer- ous ago, (where the lodes are richest). The thinness of the vein in the shales is referred to the weak action of acid on the rocks."

Fie miner, H. S. General description of the Ores used in the Chattanooga District. Trans. Am. last. Min. Eng., vol. xv, p. 757. 1837.

Flight, Walter. History of Meteorites. Geol. Mag., vol. ii, Decade ii, 1875, pp. 115-123; 152-157.

"Meteoric irons found August, 1870 Ovlfak Island of Disco. Greenland,"

are discussed.

. Supplement to a Chapter in the History of Meteorites. Geol. Mag.

vol. ix, Deo. ii, 1882.

TheOvifak iron is discussed on pp. 58, 59 of this volume. This author

here concedes the terrestrial origin of this iron. He says that:

the Greenland beds layers of lignite are found associated with the basalt, and this may have furnished the material which has reduced the Iron to the metallic tote." p. fiO.

Foerste. Aug, P. On the Clinton Oolitic Iron Ores. Am. Jour. Set., iti, xli, Jan. 1891, p. 28.

"It Is evident that the origin of the oolitic structure is not duo to a concretionary seg- regation of iron particles, but finds its explanation in the gradual replacement of the lime of the fragincntal fossil bryozoans, particle after particle, by the iron ore."

280 Bulletin No. Vi.

Foote, R. B. The Geological Features of the South Mahratta Country and Adjacent Districts. Mem. Qeol. Surv. Ind., vol. xii, pp. 268, 1876.

Forrest, R. J. On the Bilbao Iron Ore District. Trans. N. Engl. Inst. Eng.y vol. xxxiii, pp. 213-234, 1884.

Foster J. W., and J. D. Whitney. Report on the Geology of the

Lake Superior Land District. Pt. ii, pp. 50-69, 1851.

Might be quoted quite extensively. Their idea is summarized in the fol- lowing paragraph.

"On the whole we are disposed to regard the specular and magnetic oxide of Iron as a purely igneous product, in some instances poured out, but in others sublimed, from the interior of the earth. The supposition entertained by some, that it may be a sec- ondary product, resulting from the decomposition of the pyritous ores, or from the met amor ph ism of bog-iron, is inadequate to account for the accumulation of such mountain masses, or to explain its relations to the associated rocks."

. Amer. Journ. Sex., (ii,) vol. xvii, pp. 11-38, 1854, vol xxii, pp. 305-

They here state that after this series of igneous and aqueous ore beds was laid down:

"The whole series of beds, slaty, quartzose, ferruginous and trappean, were elevated and in all probability, folded, perhaps at the epoch of the elevation of the granite ranges on the north and south of the ferriferous belt of the Azoic system."

, Report on the Iron District of Lake Superior. Senate Docs.. 2d

Sess . 31st Cong . , 1850-51, ii, No . 2, 147-152 .

Foster, J. W., and J. P. Kimball. Geology and Metallurgy of the Iron Ores of Lake Superior. New York, 1865, 97 pp. with maps. Report to the Board of Directors of the Iron Cliffs Company.

Foster, J. W. Report on the Iron Smelting Coals of S. Indiana. Pitts- burg, Pa., 1871.

. Senate Documents, 1st Session, 30th Cong., 1847-8; ii, Doc. 2, pp.

773-785. 1849.

Gives a description of the iron region as studied by him in 1848. He re- gards the iron ores as of sedimentary deposition.

"These beds, so far as I have observed, present a marked similarity in mineralogloal characters and derive their origin from common causes and those were aqueous. The jointed structure and waved stratification of some of the beds prove that Igneous causes have operated, since their deposit, to modify and change their character, (p. 776.) Here they certainly bear upon their surfaces strong marks of their mechanical origin. They are regularly stratified and often contain thin seams of silex in minute grains so that a specimen on its cross fracture resembles ribbon-jasper. The lines of stratification can readily be distinguished from those of lamination. Like the slates they are often found contorted ana wrinkled, and the same facts could be adduced in both cases to prove their common origin." (p. 779.)

. Ancient Mining by the Mound Builders, in the "Pre- historic Races

of the United States. " Chicago, 1873; pp. 361-374.

Foster, Dr. C. Le Neve. Notes on Haytor Iron Mine. Quart Jour. Oeol. Soc.j vol. xxxi, pp. 628-630, 1875.

"Magnetite ore occurs in four beds interstratified with altered shales and sandstones of Carboniferous age. Above one of the beds of magnetite is a thin vein of granite, ap- parently interstratified, but which is proved upon examination to break across the rocks. The iron-ore perhaps originated in the form of beds like the Cleveland ore and has been altered into magnetite, the neighboring rocks having become extremely silicl- fled, but possibly the apparently stratified magnetite may have been formed by ferruginous emanations.

, Notes on the Perseberg Iron Mines, Sweden. Brit. Assoc. Adv. Scu

Trans. Sections, p. 60.

Magnetic "deposits were considered to have existed originally in the form of beds in sedimentary rocks, like the Cleveland Iron ore for instance, and to have been since metamorphosed; the fact that the ore is accompanied by hornbleiide.garnet, &c, is explained by the supposition that it was the ore that furnished the iron which enters into the composition of these minerals."

Fournet, J". Etudes sur les Depots Metal life res. 3 folding plates, 8vo. Paris. 1834. Published in the third volume of D'Aubisson's Traite de Gex>g- nosie.

Fox, Robert Were. Annals of Philosophy, vol. iv, p. 447. 1822. ''Electrical action might contribute to produce the extraordinary aggregation and

Ibon Obe8 Of Minnesota. 281

position of homogeneous minerals in veins." He also considered that this action is still going on in veins.

. Some Remarks on Mineral Veins . Phil. Mag. and Annals of Phil- osophy, n. s., vol. vL, p. 17. 1829. Rep. of the Roy. Cornwall Polytechnic S03. for 1836.

. Philos. Trans. 1830, p. 399; Trans. Roy. Soc. Geol. Cornwall,

1832, p. 31; 1840, v, p. 445; Phil. Mag. 1836, ix, p. 387; 1839, xiv, p. 145; Brit. Assoc. Adv. Sci. 1837,133,137; Leonhard's Jahrbuch, 1840, p. 114.

He believed that electricity has exerted a great influence in the arrangement of minerals in lodes, and that fissures are the consequences of electrical cur- rents in particular directions, and on this account they were originally formed in an E. W. direction.

. Account of some experiments on the electricity of the copper vein

in Huel Jewel Mine. Rep. Brit. Assoc. 1834, p. 572.

. Note on the Electric Relations of certain metals and metall if erous

minerals. Ph il. Trans. I, 39. 1835.

. Report of the Cornwall Polytechnic Society for 1836. Falmouth,

1837, p. 115.

"When a solution of sulphate of iron was substituted for the sulphate of copper in the cell containing the copper ore the latter appeared at first to have on its surface a deposition of iron, and this, becoming oxidated, in time formed an incrustation which resembled gossan." "Sulphurots of metals might have been thrown down by sul- phureted hydrogen, generated by the action of electricity on yellow copper ore.

. Some experiments on subterranean electricity, made at Pen- nance Mine, near Falmouth. Phil. Mag. (3), xxiii, pp. 457, 491, 1843.

Fraser, Robert. General View of the County of Cornwall. Agricultural Reports, vols, i, ii. 1794.

Frazer, Dr. Persifor. Report C, 2nd Oeol. Surv. Penn., p. 134, 1874.

With reference to the magnetites, hematites and limonites connected with limestone in York and Adams counties, he states:

"It is likely that the origin of the ore is to be sought partly in segregation and partly from alteration of iron minerals in situ. Of the former class are those glassy botry- oidal and stalactitic ores (Butcher's, Moser's banks, etc.,) whose pyramidal needles clearly show the position they held while in the course of formation.

But other cases occur in which masses of ore of irregular shape and limited extent lie between the beds of the slates and not only partake of the general dips of the latter, but share with them the most intricate and sudden convolutions."

Referring to the magnetic and specular ores which occur in the Mesozoio sandstone in the northern parts of York and Adams counties, he says (1. c. p. 137.):

"The source of this iron supply has been ascribed to the minute crystals of pyrite which undoubtedly permeate some horizons of the great calcareous deposit, but their num- ber and the porousness of the limestone as observed in connection with the ore, seem to bear no relation to the latter. It seems much more probable that the supply of Iron was obtained from the pyrite crystals of the lower slates. Even the slates which are not so situated as to permit the percolation of water through them, exhibit a porous structure, the pores being tilled with brown ochreous limonite; and this occurs to an unknown depth, and the slates seem to merge by imperceptible degrees in a direction normal to the plane of bedding, first into completely metasomatized pseudomorphsof limonite after pyrite ( but still retaining the form of the latter); then the same with a kernel of pyrite, then the pyrite itself, first with a shell and then with a mere stain of ferric hydrate; and finally the same slates are revealed porphyritic from the pyrite and not at all decomposed.

"As to the origin of the iron in these limonite beds, is the iron derived from the per- colation and solution of the pyrite disseminated through the more recent limestone beds; or does it come from the decomposed pyrite in the less recent slates? If the for- mer hypothesis bo the true one, we should expect to see an absence of limestone in the vicinity of the large deposits, for granting for the moment that the limestone contain enough pyrites to account, for the entire deposit (a Act which at least admits of some question), a percolation of water sufficient to oxidize the sulphur of these pyrite crys- tals and carry away enougli iron to produce the beds, would entirely honey-comb and finally, both by solution and attrit . on. dissipate the pyrlt If erous belts of limestone. But in and near some of the largest limonite beds we find the limestone scarcely weath- ered, and in a few cases, if any, It rendered ferruginous or even stained to any great degree by chalybeate waters. Indeed the absence of the familiar iron stain from the calcareous member of this formation is so marked, that this point of difference from the adjacent members of the series cannot fail to arrest attention. It is ob- jected in short to the hypothesis which would derive the limonite beds from the dis- seminated pyrite in the overlying limestone; 1st. That the position of the beds does not seem to effect the extent of the deposit, there is no appearance of wasting In the limestone commensurate with the effect produced, ana not even the staining from

282 Bulletin No. Vi.

chalybeate waters which must have accompanied such a genesis. 2d. Very similar de-

Josits are found in horizons far below the limestone, as at Hof ackers, the Hanover unction railroad range, etc."

He then goes on to show how the limonite may have been derived from the pyrite in the underlying slates, and quotes Rogers ,Vol. 1, p. 183. Geol. Penn.

in reference to the older limonite deposits of Lancaster county:

"An interesting inquiry is here suggested as to what can have been the geological atmospheric condition which produced the remarkable percolation which carried down so large an amount of ore out of these ferruginous beds. Was It tepid rain charged with carbonic acid in an carry Palaeozoic period? Or could it have been a long nitration of surf ace waters such as now soak the earth? Or are we to surmise an action of internal steam issuing upwards through crevices in a period of crust move- ment and disturbance? 1 am inclined to the first conjecture."

He also quotes Hunt's Essay on metalliferous deposits, (xii. Chem. and Geol. Essays, Boston, 1875, p. 229):

"The question has been asked me— Where are the evidences of the organic material which was required to produce the vast beds of iron ore found in the ancient crystal- line rocks? I answer that the organic matter was, in most cases, entirely consumed in producing these great results, and that it was the large proportion of iron diffused in the soils and waters of those early times which not only rendered possible the accumulation of such great beds of ore, but oxidized and destroyed the organic matter which in later ages appears in coais, lignites, pyro-schists and bitumens. Some of the carbon is, however, still preserved in tne form of graphite."

Later Dr. Frazer says:

"With reference to the Ferric Sulphide or pyrite, the same author ascribes its form- ation to the deoxidizing agency of decaying organic matters out of contact with air on soluble sulphates of lime and magnesia, giving rise, if carbonic acid be present, to Hydrogen Sulphide, etc.

"It seems at least a possible explanation for this more prominent determination of limonite along the edge of the limestone, that by the oxidation of the pyrites or the the slates an equivalent of sulphuric acid in addition to that necessary to form Ferric Sulphate has been produced. That this molecule of free sulphuric acid in its passage over the mica and chlorite slates has dissolved out part of their alkalies, especially soda. That this solution of sodium sulphate has mingled in the clay beds below with the solution of calcium bicarbonate produced by the drainage of rain waters over the limestone beds, giving rise to sodium bicarbonate and calcium sulphate. That this sodium bicarbonate reacting on the Ferrous Sulpoate has precipitated Hvdro- Ferrous Carbonate which lias been by oxidation rapidly converted to Ferric Hydrate, while the Ferric Sulphate has been immediately thrown down as hydrous oxide.

"The theory of the alteration in situ of various iron minerals resulting in the form- ation of many of these limonites. advanced by O. U. Shepard many years ago, and ably discussed and accepted by Dr. T. S. Hunt, cannot be disregarded in seeking the causes which produced these limonites." (1. c. p. 143. )

Titanic Iron. Proc. Am. Phil. Soc, 1875, xiv, p. 430.

, Origin of the Lower Silurian Limonites of York and Adams

Counties, Pennsylvania, Proc. Amer. Phil. Soc, March, 1875, pp. 364- 370, 433. Abstract in Amer. Journ. ser. 3, vol. ix, p. 471.

"Attributes the origin of the ore to the presence of the pyrites in the slates."

, A Study of the Specular and Magnetic Iron Ores of the New Red

Sandstone in York County, Pennsylvania. Trans. Am. Inst. Min. Eng., vol. v., 1876-77, pp. 132-143.

— . Some Mesozoic Ores. Proc. Am. Phil. Soc, 1877, xvi, 651.

. Remarks on Prof. Prime's paper. Proc. Amer. Phil. Soc., vol. xvii,

No. 100, pp. 255-258, 1877.

"The hematites are probably due to oxidization of iron-pyrites, and aggregation of the oxide at the lowest point to which water percolated."

Experiments to illustrate the formation of limonite. Proc Am.

Phil. Soc, 1878, xvii, p. 281).

. Missing Ores of Iron. Trans. Amer. Inst. Min. Eng.t vol. vi, pp.

531-542,1879; Metall. Rev. I, No. 5, 1878.

. Discussion of BlAdy's Paper on the Lake Superior Rocks in

Pennsylvania. Trans. Am. Inst. Min. Eng., vol. vii, 1880, p. 336.

. Ores of the Middle James River. Trans. Am. Inst. Min. Eng.

Virginia Meeting 1881

. Penn. Geol. Sur. Rep. Prog. C 4, p. 238, 1883.

Speaking of the Warwick' Iron Mine says:

"This extensive and interesting body of iron ore, situated just S. E. of St. Mary's Episcopal church, is in reality not a genuine lode or igneous intrusive vein, though the ore derives some of its characters from intrusive igneous action; but it is a bed or de- posit at the base or very near the base of the middle secondary red sandstone, which

Iron Ores Of Minnesota. 283

here laps on the gneiss. This Is Intermediate in its physical character and aspect between the true brown hsematlto and the magnetic oxide of iron. As on the view of its having been originally a hematite, but subsequently altered by igneous ac- tion, we might naturally anticipate, those portions of it which have undergone the highest degree of met amorphic influence are of a light grey color, quite crystalline, and partially endowed with magnetic force, whereas the less altered parts are nearly In the condition of a compact, closely cemented haematite." In reference to Orossley's iron ore pits (I.e. p. 242) be says: 'Sufficient indications prevail, and enough information is accessible in the neighbor- hood and through persons at one time commercially interested in the success of the mines, to satisfy me that these several parts all pertain to an irregular lode or a chain of closely connected lodes of igneously derived magnetic oxide of iron. This vein oc- curs between walls of gneiss rock in a low ridge just E. of the N. branch of French creek."

Speaking of the mines of West Cain county (1. o. p. 260) Dr. Frazer ad- vances briefly other theories for the formation of iron ore as follows:

"In general these mines resemble those so often mentioned and described in Report O (York County). The iron ore in them seems to have been derived from two sources, a primary and a secondary. The first is the alteration in place of strings, pockets and beds of pyrites, and other iron compounds, producing a corresponding mass of iron more or less hydra ted. The second is intimately connected with the disintegration of the rooks themselves, and depends upon it. and is in fact a deposit of oxides of iron among the impermeable clays, caused by the disintegration of the feldspars from its solution."

. Silver and Iron Mines of Nuevo Leon and Coahuila. Bead before Am* Inst. Min. Eng. Feb., 1834, p. 20. Speaking of some hematite and mag- netite at La Palerma mine near Monclova in Coahuila, Dr.Frazer says:

"The strike of the limestone and of the ore nearly agree, and the latter has been probably deposited in one of the joints or cleavage planes of the former, though it is possible that the spur itself may be anticlinal, and the iron ore deposit a true bed- vein. In either case there is the clearest evidence that the iron ore is an alteration product of the pyrite, but so complete has been the alteration that a few inches above the line of demarcation between the sulphide and the oxide of Iron, hardly a trace of the sulphur remains."

Freiesleben, . Bemerk. liber d. Harz, 1795, p. 259. Iron ore de- posits of the Harz are described.

Frotitzkewitcli, . [Deposits of Oil and Iron ore at Olkhowatka.]

Gazette dee mines de la Russxe mMdionale. No. 133. 1886.

Frus, T. [The Iron and Copper pyrites Deposits at Roros, Norway.] Nyt.

Hag. Nat. Bd. 22, p. 321. 1877.

"An account of the probable connection between the different mines in the district, And a discussion whether the ores are deposited as layers or as veins."

Fuchfl, T. Sox lea gites de f er et de ooivre gris de la petite Kabylie.Comp£. attend. A$$oc. France, p. 567. 1881.

Fuchs, W. BeitrUge zur Lehre yon den Erzlagerstutten. Vienna, 1856.

Gaetschmanii, Moritz F. Die Auf- and Untersachung von Lagerstilt- nutzbaxer Mineralien ale 1. Theil der Vollstilndigen Anleitung zur Berg- iMiikunst. Freiberg, 1856. Leipzig 1866.

Gaffe, J. R. Trans. St. Louis Acad. Sci., vol. iii, No. 1, 1873, pp. 181-192. Concludes that the Pilot Knob iron ore beds were formed by replacement, %he iron being derived by lateral secretion.

Gallois, M. de. Snr lee Minerais de Fer des Honillcret, ou Fer Carbo- nate' Lithoide. Annates des Mines. 1818. iii, 517. A valuable and learned *nemoir for the age when it was written.

Garnier, Jules. [Iron near Brest] Rev. Ocol. t. xi, pp. 76-77.

. [Iron Ores of Brittany.] Rev. QdoLt. xii, pp. 91,92. 1875.

Gelkie, Archibald. Text-Book of Geolegy. 1882. pp. 67,68. et seq.

"In the crystallized form the mineral (hematite) occurs in veins as well as lining cavities and fissures of rocks. The fibrous and more common form (which often has portions of Its mass passing Into the crystallized condition), lies likewise, in strings or veins; also In cavities, which, when of largo size, have given opportunity for the dep- osition of great masses of hematite, as in cavernous limestones (Westmoreland). It occurs with other ores and minerals as an abundant component of mineral veins, likewise in beds iuterst ratified with sedimentary or schistose rocks. It. appears abundantly as a product of sublimation in the clefts of volcanic cones ana lava streams. In veins and bods among rocks it is probably in most, cases a deposit ion from water, resulting from the alteration of some previous soluble combination of tho metal, frequently the oxidation of the carbonate. It is found pseudomorphous after

i r

284 Bulletin No. Vi.

ferrous carbonate, and this has probably been the origin of beds of red ochre Interca- lated among stratified rocks." Magnetite may "result from either aqueous or igneous action. It has likewise been observed with hematite, &c, as a product of sub- limation at volcanic foci where chlorides of the metals in presence of steam are re- solved into hydro-chloric acid and anhydrous oxides."

"Ironstone.— Under this general terra are included a number of iron ores in which the peroxide, protoxide and carbonate enter in various mixtures with clay and other impurities, They have generally been deposited as chemical precipitates on the bot- tom of lakes under marshy ground or within fissures and cavities of rocks." (p. 115.)

"The existence of beds of iron ore among geological formations affords strong pre- sumption of the existence of contemporaneous organic life by which the iron was dis- solved and precipitated." ( 1. c. p. 463.)

"Still further evidence in favor of organized existence during Archcean time in the North American area has been adduced from the remarkably thick and abundant masses of iron ore associated with the Laurentian rocks of Canada and the United States. Dr. Sterry Hunt has called attention to these ores as proving the precipitation of iron by decomposing vegetation during the Laurentian period on a more gigantic scale than at any subsequent geological epoch. (Geol. Can. 1863, p. 573.) Some of the beds of magnetic iron range up to 200 feet in thickness. Large masses also of hematite and titan iferous iron, as well as of iron sulphides occur in the Canadian Archaean series." (p. 639, Joe. cit)

Genth, F. A. Investigation of Iron Ores and Limestones from Messrs. Lyon, Short & Co . Iron Ore Banks on Spruce Greek, Half -Moon Ran and Warrior's Mark Bun, in Centre, Blair and Huntingdon counties, Pa. Proc. Amer. Phil. Soc. vol. xiv, No. 92, pp. 84-99. 1874.

Gerhard, C. A. Geschiohte des Mineral-Reichs. Berlin, 1781.

Geell, Sdndor. [Geology of the Marmaros Iron-ore]. Foldt. Kozl., vol iv. 1874.

[Geological Notes on the Marmaros Ironstone Mining District.]

Math. Termiszet. Kozlem. Kot. xii, pp. 189-216, 2 maps, 1876.

Deals with Metamorphio, Triassio, Liassio, Cretaceous, Eocene, Recent and Igneous rocks.

Gf>sner, William. On the Coal and Iron Resources of Alabama. Proc. Ac. Nat. Sci. Phila. p. 163. 1876.

GieS'er, E. [The Oolitic Iron-ores of German Lorraine.] Zeitsch. Berg- Hutt. Saline nw, vol. xxiii, pt 1, pp. 9-41. Abstract in Proc. Inst Civ. Etui., vol. xlii,p.358. 1875.

Gill, W. The Iron-ore District of Bilbao. Lond. Iron Trades Exchange, vol. xxx, p. 604; and Journ. Iron and Steel Inst, p. 63. 1882.

Gilpin, E. The Iron Ores of Nova Scotia. Trans. N. Engl Inst Ena vol. xxvi, pp. 71-89. 1877. Trans. Airier. Inst Min. Eng. vol. xiv, p. 54, 1885.

. Notes on Specimens of Iron Ores, etc, collected in Pictou for the

Philadelphia Exposition. Trans. Nov. Scot Inst, vol. iv, p. 13ft 1877.

Gjers, John. A Short Historical Sketch of the Rise and Progress of the Cleveland Iron Trade. Trans. Chesterfield Inst Eng., vol. iii, p. 63, pL xxviii, (section). 1875.

Gladly, P. [Chemico-geological notes on the Me'dnoroudiansk and and Wissokaia Gora deposits near Nijny-Tagil.J Jour, des mines russes. No. 1. pp. 96-123. 1888.

Glinzer, I)r. E. Das Eisen, seine Gewinnung und Verwendung. Pp. vii, 106, 8vo. Hamburg. 1876.

Goenaga, f gnacio de. Criaderos de hierro de Vizcaya. Mevista Minera. ser. C, vol. i, pp. 296-299, 311-314, 328, 329, 339-341, 355-35a 1883.

Goss, W. H. Cloud Hill, On the Origin of the Millstone Grit, Clay and Ironstone, etc. [Read before N. Staff. Field Club, 20 May, 1881]. 8vo, London and Derby, 1881.

Gould , Charles. Report on the Iron Ores of Londonderry in Nova Scotia, the property of the Steel Company of Canada, Limited. Pp. 52. 8vo. London.

Grand, Albert. The Coal Basin of the Asturias. Coll. Guard., voLxxxii,

Iron Ores Of Minnesota. 285

pp. 13, 51, 91, 134, 171, 211, 251, 291. 331, 371. Translated from the Proceedings of the French Society of Civil Engineers. (1876). Refers particularly to the Iron-ores of the District.

Gray* A. B, Report on Mineral Lands of Lake Superior. Executive Docs., 1st Sees. 29th Cong. 1845-46, vii, No. 211, 23 pp. with map.

Grimm, Jobann. Berg- u. Huttenm. Jahrb. d. k. k. ostr. Bergacad. 1867, vol. 16, p. 306; 1870, p. 170.

Grimm, Johann. Die Lagerstdtten der nutzharen Mineralien. Pribram, Bohemia. 1869. Prag. 1869.

Grlwnack, K. [Region of the mines of Bogoslovsk.] Journ. mines russes. No. Pp. 1-86. 1887.

. [Iron ore deposits in the Districts of Serguinsk and Oufaley.l Journ.

des mines. Noe. 4, 5, pp. 27-60; 245-278. 1888.

Grodcleck, Dr. Alb. von. Die Lehre von den Lagerstiltten der Erze. Pp. i-xii, 1-351, cuts 119. 8vo, Leipzig. 1879.

Grtiner, E. Jun. [Situation of the Iron Industry of Styria and Carinthia.] Ann. Mines, aer, 7, t. ix, pp. 471-518. 1876.

Gnignet, E., and G. Ozorio de Almeida. [Nickeliferous Meteoric Iron found in Santa-Catarina, Brazil.] Comp. Rend. t. lxxxiii, p. 917. M. Daubrie adds a note on the meteoric iron of Disko, Greenland. 1875.

Gumaelius, Otto. [Age of the Iron Ores and their use as guiding beds.] CEfvers. K. Vet Akad. Forhandl. Stockholm, pp. 30. 1875.

'Swedish oros of iron aro In stratified deposits of the same ago as the enclosing rocks. Nearly all Swedish geologists believe this. KJerulf, a Norwegian, advocates the eruptive hypothesis. Certain oros contain carbonaceous matter and indicate that organic vegetable and animal life existed at an earlier period than Is generally sup- posed. The red eury tos show the absence of reducing agencies of this sort and aro older." Gives analyses of the various types of Swedish ores. Does not mention tltani- ferous ores nor gabbro. Cannot find any tiling corresponding to Laurentian and Iluro- nlan.

. [Iron-ore deposit of Nseverhougen, Norway.] Oeol. Foren. Stock- holm Forhandl. Bd. ii, no. 28, p. 565, map. 1875.

"The chief mass of the ore lies in euritic rtx*k. elosely following the strike of an over- lying limestone. Elsewhere the ore is in the limestone itself." (Geol. Record.)

. [Iron-ore deposit of Nseverhougen, Norway, No. 2.] Oeol. Foren.

Stockholm . Bd. iii, pp. 322-335. 1877. An answer to a paper by <Jor- neliu&sen.

"Discusses whether the ore occurs as an eruptive mass or as a layer."

. [Ore-deposits and products in Scania.] Geol Foren. Stockholm

torhancU. 1, pp. 235-237. 1874.

Habets, A. [Hematite Deposits of Furness and Cumberland.] Rev. Univ. des Mines, t. xxxvi, pp. 329-335. Abstract of a Paper by M. - borger, read at the meeting of the Iron and Steel Institute, Sept., 1874.

HacketttC. A. Note on the Arvali Series in Northeastern Raj-pu tana . Bee. Oeol. Surv. Ind., vol. x, p. 84, map, 1877.

Halm, O. Zeitschr. d. d. geol Oesellsch. Bd. 15, 1863, p. 249.

Haidlnger, . Leonhard's Jahrb., 1848, p. 63. On Iron Ore Deposits in

the Eastern Alps.

. LeonharoVs Jahrb., 1849, p. 209. On Iron Ores of the Eastern Alps.

Hall, Prof. F rederick . Ores of Iron and Manganese in Vermont. Am . Jour. 8ci., i, iii, 1821, pp. 57, 58.

Hall, C. H. Mining in the Marquette Region. Jour. U. S. Assoc. Char- tool Iron Workers, vol. iv, no. 5, p. 293. 1883.

The Iron ore In the lake Superior region is found deposited in lenses, like the seeds tnaoampkla. This expression comes nearest to any thins with which I can compare tt. It Is found In lenses of unequal size. There are no veins, but simply pocket depos-

286 Bulletin No. Vl

its. We have, of course, some general Idea of where the ore may be found, but, gene- rally speaking, we do not know where the ore is until we find it Dy exploration.'*

Hall, Charles E. Lauren tian Magnetic Iron Ore Deposits in Northern New York. 32d Ann. Rep.N. Y. State Museum, pp. 135 140.

Haniel, J. [Jurassic Iron Ores of Germany.] Zeitsch. detUsch. geol. Qet. Bd. xxvi, Heft. 1, pp. 59-118, 1874.

Harden, J". W. The Brown Hematite Ore Deposits of South Mountain, between Carlisle, Waynesborough, and the Southeastern edge of the Camber- land Valley. Trans. Amer. Inst. Min. Eng ., vol. i, pp. 136-144, 1873.

"The ore, which lies along the slopes and valleys of the spurs and ridges of the mountain, associated with clays and sands, is the residue of decomposition of the slates and limestones (Silurian) and has generally a red gravelly covering of from 5 to 20 feet thick, evidently a surface wash." (Geol. Kecord, 1874, p. 117).

Harrington, H.J. Notes on the Iron Ores of Canada. Iron, n. ser.vol. v, pp. 550, 648, 806; vol. vi, pp. 74, 106; vol. vii, pp. 9, 41, 70,106.

. Notes on Chrome-Garnet, Pyrrhotite and Titaniferous Iron Ores.

Canad. Nat, n. s., vol. ix, No. 5. p. 305, 1880.

Heim, A. Untersuchungen Uber den Mechanismus derGebirgsbil dung,

Harrington, B. J. Geology of Canada. 1873-4. p. 194, et sea.

Says that the various ores of iron oocur both in veins and beds in Canada.

"None of the Oanadian magnetites, so far as I am aware, have ever been regarded as eruptive, at least by officers of the Geological survey.

"Considering the origin of our sedimentary magnetites, the question arises as to whether they were originally deposited as such, or in some other form and afterwards altered to magnetite. It seems possible that, in some cases, beds may have been formed by the accumulation of iron sands, just as they are forming in the Gulf of St. Lawrence to-day, the material being derived from the disintegration of pre-existing crystalline rocks. Such beds we should expect to contain not only magnetite, but ilmenite, and it is well known that in many cases ore on being pulverized may be more or less completely separated Into a magnetic portion containing little or no titanic acid, and a non-magnetic portion consisting essentially of ilmenite. It seems, how- ever, probable that in general their origin has been similar to that of the modern bog and lake ores. Deposits of magnetites, as a rule, do not continue of uniform thickness for any great distance like the enclosing rocks, and this is just what might be expected if we suppose them to have originally occurred as bog or lake ores which accumulated in local hollows or depressions. No ore, moreover, would be more readily converted into magnetite than bog ore, on account of the considerable proportion of organic matter which the latter contains."

Harriss-Gastrel, . Report on the Iron and Steel Industries of the

United States. Reports by Her Majesty's Secretary of Embassy and Lego* tion, Commercial, No. 18 (1874), part ii, ovo. Pp. 129-816.

Hartley, Edward, Geol. Sur. Can., 1867-69. Appendix to Reports on the Pictou Coal Field, p. 18 i Speaking of "speoular iron/' which he consid- ers to be "probably Upper Silurian," Mr. Hartley says:

t "The specular iron appeal's to exist in true fissure-veins, but of no considerable size. at any locality which I have seen. In many cases the rocks holding it appear to be much shattered, and the specular Iron, with a compact granular quartz as a veinstone, appears to fill the fissures, which are often confined to a particular bed of rock, and sometimes so numerous, that the entire bed contains a large percentage of the ore, and may be considered as a single deposit. The minor veins are often of sev- eral inches in thickness, and are included in a light greenish-drab granular quartzite, which they traverse In the most irregular manner."

Speaking of spathose ores he says (1. c. p. 185):

"Whethor this deposit should be considered a bed or a vein. Is still a matter of un- certainty. but it appears to be conformable to the stratification."

HauclMM'orne, .Zeitschr. f. d. Berg-, Hutten- u. Salinenwesen im

preuss. Staat. Bd. 16, B, p. 199.

Hauenfels, . Berg-, u. Hiittenm. JaJirb. d. k. k. ostr. Bergacad,

1864, Bd. xiii, p. 214.

Hauer and Fotterle. Uebers. d. Bergb., p. 72. Iron deposits in the Eastern Alps.

Hausmann, . Beise d. Scandinavien, pt. ii, p. 138; pt. iv, p. 69. Re- fers to Iron Gre9 of Sweden.

"Hausmann thinks that the Iron In most of the lake-ore deposits originated from decomposed iron pyrites in greenstones; and considers it probable that many of the ores in the lakes have been formed by the decomposition of neighboring bog-ores." Von Ootta, Ore Deposits, p. 462.

Ibon Ores Of Minnesota. 287

. Berg- u. Huttenm. Zeitung. 1850, p. 83, 102.

Ha wkin s, Job n . On the Phenomena of Intersected Lodes. TransMoy. Qeol Soc. Cornwall, vol. li, p. 49, 1822, Vid., also p. 290.

Hayden, F. V. Geological Survey of the Territories, 1869, pp. 78, 19a

. Geological Surveys of the Territories, 1870, p. 14.

Hayes, Dr. A. A. Native Iron from Liberia, South Africa. Annual of Scientific Discovery, 1856, p. 304.

Pure native iron, not meteoric, but probably occurring as a deposit by itself

Head, Jeremiah. Iron Mines of Bilbao. Abstract in Brit Assoc. Adv. 8ci.n 1887, p. 861. Printed in extenso in Industries for Sept. 16 and 23, 1887; also in Iron and Iron and Coal Trades Beview of Sept. 9 and 16.

Discusses at length how the ores may have been formed, and considers the origin as aqueous by the action of water containing carbonic acid.

Heath9 . Natural History of Scilly and Cornwall, 1750.

Hector, James. On the Geology of the Country Between Lake Superior and the Pacific Ocean, etc. Quart Journ. Qeol. Soc., 1861, xvii, 388-445.

. Remarks on Haematite and Spathic Iron Ores. Trans. N. Zea- land Inst, vol. xii, proo. p. 124, 1880.

Heddle, M. F. Chapters on the Mineralogy of Scotland, vii, Ores of Man- ganese, Iron, Chromium and Titanium. Trans. Boy. Soc. Edinburgh, vol. xxx, pp. 427-466, 1882.

Helmersen, G. Der Magnetberg Blagodat am Nordlichen Ural, 1837. Advocates eruptive theory.

Henkel, J. F. Pyritologia oder Kiesbistorie. Leipzig, 1725. An Eng- lish translation was published in London in 1757.

Hertftoldt, H. Meteorites and what they Teach us. Am. Qeol., vol. iv, pp. 28-38; 73-83, 1889.

Considers the Ovifak iron as directly erupted in its present metallic state, and suggests that:

"The Interior of the earth is in all probability a vast metallic mass consisting mainly of Iron," p. 83.

He m wood, W. J. Notice of a Geological Survey of the Mines of Cornwall. J*kiL Mag. and Annals of Philos., n. s., vol. x, p. 358, 1831.

— — . On the Electric Currents Observed in some Metalliferous Veins. -Jameson's Edinburgh New. Phil. Journ., vol. xxii, p. 270, 1837.

. A Lecture on the Phenomena of Metalliferous Veins. Jameson's

JSdinburgh i\ew. Phil. Jour., vol. xxii, p. 152, 1837.

. Trans. Boy. Qeol Soc. Cornwall, vol. v, 1843.

He a wood, Wm. J". On the Native Copper of Lake Superior. On Metal- liferous Deposits and Subterranean Temperature. Trans. Geol. Soc. of Corn- iwtf, vol. viii, part i, 1871, pp. 385-489.

Heurteau, E. [Geology and Mineral Resources of New Caledonia.] Paris. Abstract in Bull. Soc. Qiogr. Paris, 6 bOt. t. xii. pp. G48-G53. 1876. Ann. Mines, sCr. 7, t. ix, pp. 32-454, pi. vii-x. 1876.

Hensler. — (Note on a newly opened Oolitic Iron Ore in the Jurassic For- mation of the Teutoberger Wald.j Corr..Blatt nat. Ver. preuss. Bhein. YoL ix, pp. 113-119. 1882.

Hewitt, Abram S. A Century of Mining and Metallurgy in the United 8tates. Philadelphia. 1S7G.

Hilt, .Zeitschr. f. d. Berg- u. Hutten- u. Salinenw. im preuss. Stoat.

Bd. xiii, 1865, p. 13.

Hind, Henry Y. Report on the Exploration of the country between Lake Superior and the Bed River settlement, 1858, 425 pp., with maps.

288 Bulletin No. Vi.

Report on the Assiniboine and Saskatchewan Exploring Expedi-

tion. 1859, 201 pp., with maps.

. Narrative of the Canadian Exploring Expedition. London, I860, i,

494 pp.; ii, 472 pp.

Hitchcock, Or. Edward. Geology of Massachusetts. 1838.

On pages 350-362 are ideas whioh contain the germ of the theory adopted by Profs. Irving and Van Hise for the Huronian ores of Wisconsin, viz., original deposition in oceanic waters as a carbonate, and subsequent change to an oxide.

"At all these localities the ore is found in distinct beds in the strata; and sometimes It has a slaty structure, having every appearance of a contemporaneous origin with the rock. This porous quartz and the hydrate of iron are very common throughout the talcose slate of Hoosac Mountain, and the iron results, If I mistake not, as already mentioned, from the decomposition of the carbonate."

. Outline of the Geology of the Globe. Boston, 1853, 162 pp, with

maps.

. Geology of Vermont, 1861. Vol. 1, p. 236. Supposes hematite to

be derived from limestones containing siderite.

"The carbonate exists, as we have seen, in the limestone beneath the hematite beds, also in the mica and especially the talcose schists. Generally the specular and mag-

netic ores are found in schists that have undergone a more powerful metamorphic ac- tion than those underlying the hematites. The inference, therefore, is certainly fair, that whatever rock contains the carbonate of iron especially, and indeed any of the

other species of iron, may prove to be a source of the brown hematite. In some in- stances already mentioned, we And tho exposed portion of the vein or bed trans- formed into hematite, but not denuded; yet in general the disintegrated portion has

been more or less swept off by water and redepbsited. Hence we should say that no one rock, but all that contain other ores of iron, especially the carbonate, may have originated the hematite."

Geology of Vermont. Vol. 2, pp. 814-829. 1861. History of Iron

Workings on p. 823. Considered Iron Ore deposits to occur in beds, not veins.

Hochstetter, Fr. v. Zeitschr. d. d. geol. Gescllsch. 1864, B. xvi, p. 342.

Hodgre, James T. On the Mineral Region of Lake Superior. Proc. Am. Assoc. Adv. Sci., 1849, ii, 301-308; Ann. Sci. Disc. 1850, 260, 261.

Hoernes, R. Ein alter Eisenbergbau bei Graz. Verh. k.-k. Geol. Reichs* pp. 138-140. 1882.

Hoefer, Prof. H. [Coal and Iron Ore Deposits of North America] Vi- enna. 1878. Report of the Austrian commissioner to the Centennial Exposi- tion.

Hoffman, J". G. De Matricibus Metallorum. Leipzig. 1738.

Uofman, Fr. Karsten's Archives. 1833. Vol. 6. p. 238.

Holland, I>. [Metalliferous Deposits of Corsica.] Bull. Soc. GSol. France. 3 s6r. t. iv, pp. 30-34. 1876.

Hoi ley A. L. Notes on Iron Ore and Anthracite Coal of Rhode Island and Massachusetts. Trans. Am. Inst. Min. Eng. vi., 224, 1877.

Hopkins, — . Researches in Physical Geology. Trans. Cambridge Philos. Soc. vol. vi. pt. 1.

Horlivy,E. Ueber das Vorkommen der Brauneisensteine in Rudnitz. Zeitschr. berg- hutt. Ver. Karnten. Bd. xii. p. 277. 1880.

Hougrhton, Douglass. Metalliferous Veins of the Northern Peninsula of Michigan. Am. Journ. Sci., 1841, (1,) xli, 183-186; Trans, of the Assoc. Am. Geol. and Nat., 1840-42, pp. 35-38; Edinburgh New Phil. Journ., 1842, xxxiiL 201, 202.

"Dr. Houghton conceives these to be veins of sublimation, or in other words, to be simple fissures filled from below by the metal in a vaporous state."

Hudleston, W. H. Excursion to Northamptonshire. Proc. Geol. Assoc.. vol. iv, No. 2, pp. 123-124, 1875.

"The Ironstone of the Northampton Sand is described as formed by the substitution of iron for lime in the original rock, the carbonate of iron having been afterwards chiefly changed into hydrated peroxide."

Hughes, T. W. H. Notes on some of the Iron Ores of Kumaon. Bee.

Iron Ores Of Minnesota. 289

QtoL Sur. Ivd\, vol. vii. pt. 1, pp. 15-20. See also Supplement to Gazette of India, Aug. 22, pp. 1466-68, 1874.

. Second Note on the Materials for Iron Manufacture in the Rani-

ganj Coal Field. Rec. Oeol Surv. Ind., vol. vii, pt. 3, pp. 122-124, 1874.

. Note on some of the lion Deposits of Chanda, Central Province

Supplement to Gazette of India, Aug. 22, pp. 1489-1491, 1874.

. The Wardha Valley Coal Field. Mem. GeoL Sur. Ind., vol. xiii,art

1. pp. 154, 3 maps, 1877.

full, E. Blenheim Iron Ore. Geology of Country Around Woodstock. Mem. GeoL Sur., 1857.

If nil, Prof. Edward. Notes on the Hematites of Counties of Cavan and Ijongford. Bead before Royal Dublin Society June 3, 1872.

"It (the hematite), therefore, does not occur as a lode or vein, traversing the strata In a highly inclined position, but rather in the form of lenticular beds of extreme ir- regularity."

Explanatory Memoir to Accompany Sheets 21, 28 and 29 of the Maps

of the Geological Survey of Ireland. Hvo. Dublin, 1876.

"The iron ores (haematites) and the lithomarge are extensively worked, and are very valuable; they appear to be of lacustrine origin."

Hunt, Robert. Mineral Statistics of the United Stock of Great Britain and Ireland, for the year 1874, with an Appeadix. Pp. zv, 279, 8vo. London, 1875. The character of the iron ores from the various distriots is stated.

, British Mining. Pp. 956, 8vo. London, 1884.

Hint, Ttiomas S terry. Amer. Nat. April, 1875; Am. Jour. Sci. (ii) zzzi 892-414. 1861.

. Chemistry of the Primeval Earth. Smithsonian Report, 1869, p. 191.

In this paper is advocated the theory that the beds of iron ore in the Archaean are indications of the existence of vegetable life at that early period.

"The evidences of this reducing and dissolving action of organic mutter are met with not only In the fire-clays and Ironstones of the Carboniferous system, and among sec- ondary, tertiary and modern deposits, but on a grand scale in the Laurent ian system. where great thicknesses of sediments are found almost destitute of iron, while beds of faon ore more extensive than at any subsequent periods are evidences of the abundance of organic matters at that earlv time."

. Geol. Sur. Can. 1866-69, Part 8. Abstract in Can. Nat. and Quart.

Jcurn. Sci, n. s. vol. vi, No, 1, Sept. 1871. Discusses Iron Sands, etc., and has tome interesting historical accounts of early iron workings in the United States.

. Chemical and Geological Essays, p. 22. Rep. Prog. GeoL Can,

1866-69, pp. 2H1, 269. Can. Nat, vol. vi, p. 79, 1872; vol. vii, p. 127.

. The Origin of Metalliferous Deposits. Trans. Am. Inst. Min. Kng

1872, i, 418-426.

. On the Crystalline Bocks of the Blue Bidge, and on their decom-

PcmmhI condition. Proc. Bost. Nat. Hist. Soc. vol. zvi, part 2, pp. 116, 117. 1874.

These consist of hornblendic and micaceous schists, completely decomposed to a

9pth of 50 feet or more, being changed to a reddish unctuous clav. with interbedded

flyers of quarts showing the original inclination of the rocks. The removal of the

i-oxldes is said to be the source of the large deposits of hydrous iron-ores found at

foot of the Blue Kldge In the Appalachian Valley. The decomposition is supposed

have taken place at very ancient times, when there was a highly carbonated atmos-

Miere." Oeol. Record, 1874. p. 121 .

. The Geology of the North Shore of Lake Superior. Trans. Am<

nsL Min. Eng., 187.% ii, 58, 59.

— — . Geoirnoatioal History of the Metals. Trans. Amer, Inst. Min. Ena >ol i, pp. 381-846. 1874.

. J*I>maen the crystalline stratified rocks of Eastern North America Into four groups, Uthologlcally and strati graphically distinct— Laurentian. Norian (or Lahradorlan, taper Laurentian of Logan), Huronlan and Montalban, (gneiss and mica schist of the Wilte Mountains), and thinks it probable that other like formations of crystalline

may have been almost entirely swept away. The Laurentian Is remarkable for

ttposiUof crystalline iron -ore, chiefly magnetic, the ores occurring in beds or masses £ contemporaneous deposition. The Norian is remarkable for tltanlferous iron-ores. the Huronian are the great deposits of hematite and magnetite of Lake Superior;

290 Bulletin No. Vi.

chromic Iron-ores seem to be characteristic. The distribution of ores in other rocks is also noticed." Oeol. Rec. 1874, pp. 120, 121.

Hunt,T .S. The Coal and Iron of Southern Ohio, considered with relation to the Hocking Valley Coal Field, and its Iron Ores, etc., with a view of the coal trade of the West. 8vo., pp. 78. Salem. 1874.

. Natl. Acad. Sci. Nov. 1874

As to the origin of brown hematite ores. Hunt is of the opinion that they were once beds of rites in Huronian schists, now decayed.

. The Development of Our Mineral Resources. Harper's Magazine

1875, h. 82-94.

. The Cornwall Iron Mines and some Related Deposits in Penn- sylvania. Tram*. Ainer. Inst. Min. Eng.% vol. iv, pp. 319-325, 1876.

"Believes these ores to come from the alteration of deposits of carbonate, and in many oases, of sulphuret of iron, oxidized inattw." since they are in many places inter- stratified with the brown haematite.

. Am. Ahsoc. Adv. Sci. 1876.

"The crystalline character often exhibited by these so-called Primal slates was noticed by Rogers, who ascribed it to their subsequent alteration by intrusive rocks. A careful study of this series has, however, convinced me that itsdetrital beds include, in many parts, deposits of chemical origin, such as beds of crystalline magnesian limestone, often holding serpentine, chloritic. steatitic and micaceous schists and es-

fecially great beds of magnetic and more rarely specular or red hematite iron ores. The aspect of these ores and their associated rocks is unlike that of the other crystalline series already mentioned." "These strata include deposits of carbonate of iron and others of pyrites, from the alteration of one and the other of which, in the deeply decayed portions of the strata (now converted into clays) have been formed the great quantities of hydrous iron ores which characterize, throughout the whole extent of their outcrop, the Primal and Auroral strata. These are the Lower Taconic rocks of Emmons."

On the recent formation of quartz, and on Silicirlcation in Califor-

nia. Am. Jour. Sci. (iii.), vol. xix, pp. 371-2. 1880.

. The Genesis of certain Iron Ores. Abstract of a paper read at the

Boston meeting A. A. A. S., Aug 28, 1880.

"The changes of slderite and pyrite under atmospheric influences were next consid- ered. The latter, by oxidation yields, as is well known, ferrous sulphate. Its frequent conversion by sub-aerial decay into limonite was conceived to be due to the interven- tion of water holding carbonates, which conjointly witli oxygen, changes it into hy- drous peroxide (limonite) the latter often retaining the form or the pyrites. The trans- formation of carbonate of iron into hydrous peroxide is a familiar fact.

Limonite ores may thus be produced in three ways. They are sometimes formed by the peroxidation and precipitation of dissolved ferrous salts, as in the bog -ores: but more f requently from the alteration in *itu of deposits of pyrite or siderite. Such as these are the "limonites" which mark the outcrops of beds or veins of pyrites in the decayed crystalline rocks of the Blue Ridge. The similar ores found in the decayed Taconic schists of the great Appalachian valley can be shown to be due in some cases to the alteration of included masses of pyrites, and in others to the alteration of simi- lar masses of siderite, lH>th of which species are found in the unaltered Taconic rocks, as indeed at various other horizons in the geological series."

Goal and Iron in Southern Ohio: the Mineral Resources of the

Hooking Vallev. Account of its Coals, Iron Ores, Blast Furnaces and Rail- roads. 8vo. pp. 152. Boston. Map. 1881.

. Coal and Iron in Alabama. Trans. Ainer. Inst. Min. Eng. Bos- ton Meeting, Feb. 1883.

"As regards the brown hematites these hydrous ores have been generated, as has been shown by myself and others, by the alteration in situ of interstratified masses and layers, in some cases of carbonate of Iron and in others of pyrites, included in the more or less argillaceous strata now changed to clays."

Trans. Amer. Inst, Min. Eng.t vol. iv, pp. 319-325. 1876.

'The decayed crystalline schists which there (Pennsylvania) contain the limonites were not Huronian but Taconic. (2nd Penn. Report, E. Pt. 1, p. 203.) The crystalline, magnetic and specular ores found along the borders of the Mesozoic basin of Pennsylvania are not to be confounded with the ores of Huronian or of Laurenti&n age, but alike by their geological position and their mineralogioal associations differ from those and appear to belong to a distinct ore-l>earing horizon. Ther are, all of them, really contemporaneous deposits included In the Primal slates (H. D. Rogers) which correspond to a portion of the Lower Taconic series of Emmons, and belong, in my opinion, to a lower horizon than the Potsdam sandstone of the New York system." "Those magnetic and specular ores of the Primal slates have verj close geological relations with the brown hematites of the region, some of which be- long to the same Primal slates. These ores, which I believe to come from the altera- tion of deposits of carbonate, and in many cases, of sulphuret of iron, oxydized in

Iron Ores Of Minnesota. 29

situ, are, in certain deposits of the region, interst ratified with crystalline magnetic and specular oxides; the whole being imbedded in the clays which nave resulted from the more or less complete decomposition of the enclosing crystalline rocks."

Hutton, Dr. James. Theory of the Earth, 2 vols. 1795.

It is inferred that the materials which fill the mineral veins were melted by heat, and forcibly injected in that state into the clefts and fissures of the strata. This idea was particularly applied to iron ore deposits. Vid. Illustrations of the Huttonian Theory of the Earth by Prof. John Playfair, 1802. Also Re- port on the State of Knowledge Respecting Mineral Veins, by John Taylor, Brit. Assoc. Rep., 1833, p. 10.

Igelstrom. 1j. J. Bidrag till fragan om malmernas af Tabergstypen geog- noei. Geol. Foren. Stockholm . Bd. vi, pp. 319-322, 1883.

Berg-, u. Huttenm. Zeitung. 1866, p. 21.

Irving, Roland D. On some Points in the Geology of Northern Wiscon- sin. Trans. Wise. Acad. 8ci„ 1873-74, ii, 107-119.

"In this (central) portion of the group occur all the famous ores of the Penokio Rauge — and indeed all the ores whose existence Is yet known— these ores being never inter- calated lenticular masses, independent of the enclosing rocks, but simply portions of the great (Huronian) group— Ave hundred feet thick— of magnetic and specular schists, carrying a larger portion of the oxides than the general run. '

Note on the Stratigraphy of the Huronian Series of North-

ern Wisconsin; and on the Equivalency of the Huronian of the Marquette and Penokee Districts. Am. Jour. Sci., 1879, (3,) xvii, 393-398.

Mineral Resources of Wisconsin . Trans. Amer. Inst. Min. Eng.,

toI. viii, 1880.

Origin of the Ferruginous Schists and Iron Ores of the Lake

Superior Region. Am. Jour. Sci., (iii) vol. xzxii, Oct. 1886.

"Two classes of theories have been maintained to account for the iron ores of the Take Superior region. According to one of these, these ores, with more or less ac- companying rock material, and particularly the Jaspery schists so often associated with them, are in the main of eruptive origin; according to the other they are of sedimentary oilgln, the original sedimentation having been mechanical or chemical, or both, according to different theories. Ou the eruption theories subsequent chemi- cal alteration Is allowed to come in to some extent to explain present conditions, as It Is also with some of the sedimentation theories; but the latter theories appear to appeal In the main to a regional metamorphism as the cause of present conditions.

Those who have maintained the theories of a sedimentary origin have relied chiefly upon the common intimate interlaminatlon of siliceous and ferruginous materials; upon the manifest restriction of the ores and jaspery schists to definite stratlgraphi- cal horizons; upon their interfoldlng with other members of the same series, and upon their apparent gradation in places Into plainly fragmental deposits. These con- ditions being taken to indicate original sedimentation, different authors have imag- ined the unaltered deposits to have been argillaceous carbonates like those of the coal measures, to have been brown ores like those found under bogs, or accumulating In shallow lakes, at the present day, or to have been magnetic iron sands like those of modern sea-shores. All of these theories appear to regard the silica of the jaspery aehlsts and ores as having been sand; its present non -arenaceous, non-fragmental condition being taken to be the result of metamorphism.

Advocates oi an igneous origin for the iron ores and associated jaspers have been lew, and It Is noteworthy that their observations have been confined to the Marquette region, where the disturbances have been great, and where the difficulties are conse- quently greater than in other regions. In support of an Igneous origin for these ma- terials, which are supposed on such theories to have been intruded as bosses, or to have formed overflows at the time of the accumulation of the associated strata, have Deen cited particularly: (1) an irregularity of contact of the ore and Jasper with the adjoining schists; i2) the projection of stringers of ore and jasper into the adjoining schists; (3) the induration of the adjoining schists; (4) the curvature of schistose Cleavage by ore intrusions; and (5) the occurrence of fragments of ore and jasper in Immediately overlying quartzite of the same series, this indicating their existence

in thelrpresent conditions of induration prior to the accumulation of this quartzlte. QL B. Wadsworth, BuU. Mu#. Comp. ZitoL ol. vli. No. 1.) Ou this theory the lamina- tion of the ore and Jasper is taken to be probably a fluidal structure, and the inter- heddlng of ore and Jasper with the schists to 1m the result of a contemporaneous flow- ing of lava. Having carefully examined the localities cited by the last advocate of an eruption theory as proving the al>ove facts, I feel able to say that the occurrences, save the last named (5) are trivial matters occurring within the space of a few inches, or feet at most, and.tnat all are more easily applicable— as irregularities in original deposition, as Irregularities due to the crumpled condition of the strata, or, and this Chiefly, as due to Infiltration of iron oxide and silica into cracks in the rocks, and the replacement of rook material by such substances— on theories of original sedimenta- tion of the iron beds than on those of an eruptive origin, the last named point, vis.: the ooranenoe of fragments of the banded jasper In the immediately overlying quart, more consideration, since it certainly indicates that to some extent at

taeoeenrre stte,deserv

292 Bulletin No. Vi.

least, these substances had reached their present condition at an early day. But cooling from a state of fusion is not the only way of reaching rapidly the indurated condition, and a former fused condition seems to he negatived at once by the nature of the material- quartz and iron oxide. Again, the silica, which frequently forms so prominent a part of the ferruginoxs schists, and which is at times jaspery. hut is far more frequently cherty or even cLalcedonic— a point hitherto quite unrec- ognized in publications on this subject— presents every evidence, both in the thin sec- tion and in the field, of a chemical origin. In the thin section, in that it shows ordin- arily no trace of a fragmental texture, even when relatively course-grained, and in that it approaches more commonly to the peculiar chalcedouic or even amorphous forms known to occur only with silica deposited directly from solution; besides which it traverses and follows the banding indifferently and in such a manner as to place Its secondary nature beyond all doubt. In the field, in that the jaspery or chalcedonic silica, while in the main closely interfcanded with the more ferruginous portions of the rock, is seen also to intersect the bands, or even to appear in the shape of a ce- ment to a breccia ted mass of fragments of the interbanded materials. All theories of a formation of theste ferruginous rocks by metamorphism. or recrystallization in situ, from some sort of sedimentary deposit, seem to regard the jaspery or cherty material as representative of a fragmental siliceous ingredient in the original deposit— either a quartz sand or a fine "siliceous silt." On these theories this substance has been re- crystallized from the fragmental condition The facts above cited refute any such explanation, and prove incontestably the chemical origin of the silica. We may cite in addition, moreover, the fact that in these siliceous iron rocks themselves there is at times an admixture of fragmental quartz, which in the thin section is always sharply defined as an original ingredient, and easily distinguishable from the water-deposited silica. The latter is frequently identical with that cherty material which has often taken the place of large oodles of limestone among the unaltered formations.

"These considerations leading to the rejection of a metamorphic origin for any of these materials, as others had previously led to the rejection at an igneous origin, it followed that we were thus restricted to some theory which should account for the precipftation of most of them essentially in their present conditions, with perhaps some slight internal rearrangement, or to one in which the production, from some form of sedimentary deposit, of the conditions now obtaining, should be assigned to metasomatic processes, carried out in part at least, at a very remote period. ♦ While we have, perhaps, in the deposition from some modern siliceous springs, a slight analogy to the interstratificatfon of iron sesquioxide and silica, this analogy is, after all, but slight, and any theory of deposition from springs fails entirely to se- cure in its support any modern analogues for the various magnetic and actinolitic schists whose production must be explained, Again, there is nothing in the structure of these deposits to indicate spring deposition, and everything to indicate deposition in bodies of water. But of the formation of such deposits by chemical deposition in bodies of water we certainly have no modern instances.

'Later, as further study developed the fact that the least altered forms of the fer- ruginous schists contain a considerable proportion of some carbonate— the amount of carbonate increasing inversely with the amount of disturbance and alteration— the idea of a possible formation of these rocks by chemical deposition approximately in their present conditions gave place to views which included the idea of a replacement of some rock, originally dolomitic or calcitic. by siliceous and ferruginous substances. That the original carbonate was itself ferruginous was an idea that presented Itself, but had been abandoned. But a suggestion from Professor Pumpelly led to a further chemical examination with regard to this point in which much new material was included. The result was the establishing the general ferriferous character of the original carbonate; while further quantitative analyses made in the chemical laboratory of the U. S. Geological Survey showed that it is often even a genuine sid- erite. though magnesian. This point once established, all of our field ana laboratory observations seemed to fall suddenly into line, and to establish the truth of an hy- pothesis long since advanced, viz: that these ferruginous rocks were once carbonates analogous to those of the coal measures; though the advocates of this hypothesis can hardly have realized the ground it could be shown to cover, and they certainly did not have any conception of the nature of the altering process."

Jackson, Dr. B. M. S. Nittany Valley Iron Ores, 1838-89.

Considered them to be deposits in loco originali of the iron (as hydrated peroxide) set free from the limestone or dolomite rooks during their gradual erosion and dissolution. Vid. Am. Jour. Sci., (3), 1875, ix, p. 437.

Jackson, i 'has. T. and Francis Alger. Mineralogy and Geology of a part of Nova Scotia. Am. Jour Sci. xiv, 1828, pp. 305-330 :xv, pp. 182-160,

Jackson, Charles T. Report on the Mineral Lands of Lake Superior. Contains Report by Messrs. Locke, Charming, McNair and Whitney. Senate Docs., 1st Sess. 80th Cong., 1847-48. ii., No. 2, 175-230.

. Mineral Lands of Lake Superior. Contains Reports of J. W. Foster

and J. D. Whitney. Senate Docs., 1848-49, 2nd Sess. 30th Cong., ii., No. 2, 153- 163; Executive Docs., 1848-49, 2nd Sess. 30th Cong., iii., No. 12, 153-163.

Report of the Progress of the Geological Survey of theMineral Lands

of the United States in Michigan. Senate Docs., 1848-49, 2d Sess. 80th Gong., ii., No. % 185-191; Executive Docs., 1848-49, 2d Sess. 80th CoDg., iii., No. 12,

Iron Ores Of Minnesota. 293

Jackson, C. T. Remarks on the Geology, Mineralogy and Minea of Lake Superior. Proc. Am. Atsoc. Adv. Sci., 1849, ii., 283-288.

. On the Geological Structure of Keweenaw Point. Proc. Am. Assoc.

Adv. Scu, 1849, ii., 288-301.

Remarques eur la GGolosrie du District M<*tallifere du Lac Supl-

rieur. Bull. Soc. Oeol. France, 1849 50, vii., 667-673. Annates des Mines. 1850, (4,) xvii., 103-115.

. Report on the Geological and Mineralogical Survey of the Mineral

Lands of the United States in the State of Michigan. Contains Reports by Messrs. Jackson, Foster, Whitney, Locke, Barnes, Burt, Hubbard and others. Senate Docs.,, 1st Sess. 31st Gong., 1849 50, No. 5, iii., 371-935; Am. Jour. ScL, 185L (2,) xi, 147, 148.

. Geology, Mineralogy and Topography of the Lands around Lake

Superior. Senate Docs. 1851-52, 1st Sess. 32d Cong., xi, 232-244. In Andrew's Report

. Ueber den Metallfuhrenden Distrikt am Obern See im Staate

Michigan. Karsten's Archiv. 1853, xxv, 656-667.

. Observations sur quelques Mines des Etats-Unis et sur le Gres

Rouge du Lac Saperieur. Comptes Rendu*, 1854, xxxix, 803-807.

Jacquot, Euffene. Annates d. Mines, 1849, vol. xvi, p. 427. Iron deposits in the Ottange Valley, Fraoce.

Jager, Aug. Ueber die Eisenerzablageruug von Lothringen-Luxemburg Ac. Stahl und Eisen, Bd. 1, pp. 138, 171, 1881.

Jars, SL G. Voyages Mtallurgiques. 3 vols., 1781.

Jasche . Mineralogische Studien, 1838, p. 4.

Mentions Hartz Iron Ores and the manner of their occurrence.

Jefferson, J. G. Clausthal Mining School Notes. A series of Lectures. . Journ.f vol. xlvii, 1877.

Jones, Jos. T. Observations on the Claybdnd-Ironstone, &c. Proc. S. Wale* Inst. Eng., vol xii, p. 255, 1880.

> James E. The Marquette Iron Region. Jour. U. S. Assoc. Charcoal Iron Workers, vol. ii, No. o, p. 2C5. 1881.

Jordan, S. Notes on the Resources of the Iron Manufacture in France. Journ. Iron Steel Inst., pp. 316-315; Discussioj, pp. 316-356, 1878. "Indigenous French iron ores. Treats of all varieties of iron ore."

J add, John W. Geological Survey Memoir. Geology of Rutland, <feo. pt. vi. Origin of the Northampton Sand. (General Features, Lithologioai, Jftioroscopical, and chemical characters, Mode of Formation, causes of Redis- tribution of the Iron.) 113-138. 1875. 8vo. London.

Volcanoes. 1881. p. 319. Mr. Judd says:

"A careful study of all the facts of the case by Lawrence Smith, Daubre*o and others 'well acquainted with the phenomena exhibited by meteorites, has led to the conclu- sion that the large iron-masses of Ovlfak, as well as as particles of metallic iron dif- fused through the surrounding basalt, are all of terrestrial origin, aud have been brought by volcanic action from the earth's Interior. These researches ap- Dear to warrant the hypothesis that the Interior of our globe consists of metallic substances unoombined with oxygen, and that among these metallic substances iron plays an important part. Our globe, as wo know. Is a great magnet, and the remarka- Ne phenomena of terrestrial magnetism may also not improbably find their explana- tion In the fact that metallic Iron forms so large a portion of the earth's interior.'*

Jullen, A. A. The Genesis of tie Crystalline Iron Ores. Proc. Acad. Ufat. 8H. Phil. 1881 p. 335.

"In an age which admits its special indebtedness for material advancement to the Industries connected with the manufacture of iron, and in a country in which these In- dustries have been so vastly developed as In this, the question of the origin of that metal has long possessed, and must always retain, a high degree of interest. So far as relates to the limonites,turgltes and bog-ores, the question has met with a satisfactory answer In the theory of the concentration of these ores by the percolation of organic adds, as fully presented in the writings of Bischof. Hunt and others; especially as the

294 Bulletin No. Vi.

process can be actually observed and studied in progress in the lakes, marshes and bogs of the present day. But the mode of genesis of the crystalline ores— hematites, magnetites, menaccanltes. and their mixtures— enveloped partly in the sedimentary strata and chiefly in the still more ancient crystalline rocks of Archaean age, can be only inferred from analogies. Nor can the problem be considered as solved by any or all of the numerous theories which have so far been advanced. These theories may be naturally divided into two classes, as they may refer the iron-ores, enclosed in the subterranean strata, to an extraneous or to an indigenous origin.

A. Theories Of Extraneous Origin.

To begin with the former, we have

1 Meteoric fall. This startling theory has been suggested to account for the enormous mass of martitic specular iron-ore, claimed to be the most extensive known single de- posit of Iron-ore on the continent, that of Cerro de Mercado, two miles from Durango, Mexico. Cerro de Mercado is a mountain.ono mile long, one-third of a mile wide, and from 400 to 600 feet in height. The ore-surface of the mountain aggregates over 10,000,- 000 square feet, but there are indications that the ore is not all above ground, and the the engineers' report declares it to be an enormous aerolite, half imbedded in the level plain on which it lies.' Such a view is sufficiently controverted by the mineralogical constitution of the mass, and its structure— 'Immense veins of specular iron-ore standing nearly vertical.' (B. Silliman, Am. Jour. Sci, 1882 iiii., xxiv, 375; and J. Birk- inbine. Chicago Min. Jour. 1882, il., No. 4, p. 184.)

2. Eruption dykes. According to this genetic view, the crystalline iron ores have been extruded from the interior in a pasty condition like a lava, through fissures in the superficial strata. (J. D. Whitney, The Metallic Wealth of the U. S., p. 433.)

This theory has been recently further developed in reference to the banded jaspery iron ores of Michigan, and it has been advanced that the banding and lamination of these ores are similar in character and orlgiu to those strongly marked in rhyolytes, furnace slags, etc. CM. E. Wadsworth, Proc. Bost.Soc. Nat. Hist., Ih80, xx, 470; and Am. Jour. Sci., 1881, (Hi,) xxiL 403.* The mineralogical constitution and infusibility of these ores, their distinctly sedimentary lamination, etc., clearly testify to the unsoundness of these hypotheses. (J. D. Dana, Am. Jour. Sd., 1881, (lil), xxli, 320, 402; J. 9. Newberry, Sch. of Mines Quarterly. Nov. 1880.)

3. Sublimation into fissures. The inconsiderable crusts of specular oxide, which have been observed in the vicinity of volcanoes, such as Vesuvius, have certainly no rela- tion to the enormous bedded masses distributed throughout the world, at a distance from volcanic centers.

B. Theories Of Indigenous Origin.

The theories of this class differ in ascribing the origin of iron ores to either chemical or mechanical agencies. Nine chemical theories have been proposed.

4. Concentration from ferriferous rocks or lean ores, by the solution and removal of the predominant constituent, e. q. silica, by means of thermal solutions. Indeed it has been shown (J. P. Lesley. Report on Brown Hematite Deposits of Nittany Valley, Pa., R. Pumpelly, Geol.Surv. Mo., Prelim. Rep. on Iron Ores, 18?2.8et seq„) that a concen- tration, in a similar way, of the ferriferous constituent, in the lower Carboniferous limestones and dolomites of the Mississippi basin through the removal of the more soluble calcium carbonate by carbonated waters, has apparently produced extensive deposits of limonite. in loco originali. But there is no evidence of the relation of any of the crystalline iron ores, enclosed in sediments of plainly sub-marine origin, with any such subaerial process. Even were the theory satisfactory in regard to the pure ores, the essential question remains unanswered, viz., the genesis of the original ferriferous rocks or lean ores' themselves.

5. Saturation of porous strata, e. g.. of sandstone, by infiltrating solutions carrying iron oxide. (Emmons, Nat. Hist. N, F.,4v, 94. 1842 ) This theory, however applicable to certain rock masses rich iu hydra ted ferric oxides, can account neither for the con- centration of the huge and pure bodies of the true ores, nor for the alternation of siliceous and ferriferous laminae and layers in the lean ores.

6. Infiltration into subterranean chambers and channels, depositing pipe-ores and llmon- ites in widened crevices and joints of the more recent limestones or other sedimentary rocks, or in cavities overlying impervious strata, (F. Prime, Jr.. Am. Journ. Sci., 1875, (Hi), lx, 433). The lenticular form, laminated structure. Intercalation of the matrix, enclosure of the ore-bodies in the bedding-planes. and other facts, markedly distinguish the crystalline ores from the llmonites formed by such a process.

7. Decomposition of pyrite,o,nd other ferruginous minerals,enclosed in decaying schists and transfer of the iron-oxide in solution as ferrous sulphate. (T. S. Hunt. Nat. Ac. Sci., Nov., 1874.) The precipitation of the iron-oxide has been sometimes attributed to simple oxidation, more usually to the production of ferrous carbonate, by reaction between the ferrous sulphate and the calcium carbonate of the limestone, afterwards converted into limonite by oxidation and hydration. (6. Bischof, Chem. and Phys. Geol., 1,236; P. Prime. Jr., loc. cit.; W. B. Rogers, Geol. Penn., 1868, ii, Pt. ii. 722. 729). This theory has had only local application, even to the llmonites, and its connection with the crystalline ores Is rendered improbable by the absence of associated lime- stones, or, ii present, of evidences of their erosion, etc.

8. Derivation from original deep-sea deposits of hydrous ferric oxide; or of ferrous car- bonate, dehydrated bv subsequent heat, and deoxidized by hydrogen. (J. P. Lesley, The Iron Master's Guide, p. 374, 1866). By a modification of this theory, the jasper-ores have been connected with the ferruginous and manganlferous nodules which have been dredged from the surface-layer of the deep-sea ooze of our present ocean-bottoms.

2V. O. Crosby, Proc. Bost. Soc. Nat. Hist,, 1879, xx, 168.) All the evidence so far gathered, owever, shows no correspondence between the phenomena; the ferriferous contents of the ooze consisting of irregular crusts and nodules, never continuous nor interlaml-

.Iron Ores Op Minnesota. 295

nated with silica. On the other hand there is abundant evidence that the strata asso- ciated with the crystalline iron ores are mostly shallow-water or shore deposits,in large part conglomeritic.

0. Deposit from springs,hy oxidation and precipitation from solutions of ferrous car- bonate, on exposure to the air at their issue. (G. Bischof, Chem. and Phys. Geol., i, 155- 157, 166-167.) Such deposits, it is admitted, are local and limited, and the theory can have no bearing on the ordinary wide-spread crystalline ores.

10. Alteration of diffused ferric o.tt'd£.d inseminated through sediments.into ferrous car- bonate.in presence of vegetable matter, and its accumulation in particular layers by processes of filtration and segregation. (W. B. Rogers, Geol. Penn., 1868, il, Pt. ii, 737). The vague processes thus invoked to account for t lie accumulation of ores are not ac- cepted as satisfactory, even for the carbonates of the coal measures, lying in definite planes. Nor do the sheets and beds of crystalline ores usually show the irregular characteristics which may be attributed to processes of segregation.

11. MetamorphismofancieiUbogtres. The reference of the crystalline iron ores to this origin has been thus stated by Dr. II unt: '1 see no reason for assigning any other than a sedimentary origin to the magnetic and specular iron ores of the crystalline schists; nor do I conceive that the conditions under which they were deposited differed essentially from those which at the present day give rise to llmonite and ochre.' (Letter of Dr. T. S. Hunt. 1858. quoted in Lesley's Iron Masters' Guide, p. 3G5. See also vanuxeni, Nat. Hist. N, Y.. Geol., 3d District, p. 267.) Again he observes: 'The organic matters reduce the peroxide of iron to a soluble protoxide, and remove it from the soil, to be afterwards deposited in the forms of iron ochre and iron ores, which by sub- sequent alteration become hard, crystalline and insoluble.' (Chem. and Geol. Essays,

In opposition to this theory, in its reference to subaSrial l>ogs or marshes (see Dana, J. D.), it must be considered that the enclosing and associated strata bear universal testimony, both In their contents and the form of their superficies, to their submarine mode of deposit. On the other hand, if the bog-ore theory were applicable to these ores, every ore-bed would imply a terrestrial plane for the reception of the subaGrial bog deposit, i. e.% for every ore-lens a corresponding elevation above the sea-level and ensuing subsidence of the entire underlying stratum. On the contrary, no evidence has been shown in the Archaean strata of any subaGrial surface; all appear to be sub- marine sediments, and that still more ancient rocky terra ne which formed the coast whose debris, poor in iron, was deposited or strewn over the ancient Laurentian sea, and upon whose surface bog-deposits may have rested, seems to have been entirely buried up beneath later sediments.

12* The metamorphtsm of ancient lake-deposit* oflimonite passing into hematite, corres- ponding to the oolitic 'fossil ore* of the Clinton group of the Upper Silurian, to the Tnustard seed' ore described by Slormalm*, which is deposited near the banks of the present Swedish lakes, etc.. (B. Von Cott a. Ore Deposits, 249, 284, 461: The Geologist. IMS, 96.) This Lake ore' theory (Dr. J. S. Newberry. 'The Genesis of Our Iron Ores/ Sen. of Mines Quarterly, Nov. 1880,) seems to be valid for a large number of huge de- posits of the crystalline ores, and also satisfactorily accounts for the abundant pres- ence of apatite in many ore-beds. It may be fittingly applied, therefore, in explana- tion of the phenomena seen in those deposits which contain a notable amount of cal- cium phosphate; most of those which consist of hematite, or of magnetite passing Into or occasionally enclosing hematite, and the beds of magnetite which present the botryoidal and concretionary aspect and radiated structure of llmonite. On the other hand, the poverty or almost entire absence of phosphorus and sulphur in certain ore beds, and the extreme abundance of titanic acid, free alumina, garnet, olivine, etc., in others, demand some other explanation.

Two mechanical theories are yet to be considered.

18. Violent abrasion and transport. This theory may l>c best stated in the words of its author:

That the Azoic period was one of long-continued and violent action cannot be doubted, and while the deposition of stratified beds was going on, volcanic agencies, combined with powerful currents, may have abraded and swept away portions of the erupted, ferriferous masses, re-arranging their particles and depositing them again In the depressions of the strata.' f.I. D. Whitney. Metallic Wealth of the IT. 8., 434.)

This theory of Whitney was supplementary to his main theory of volcanic eruption of the ferriferous masses, rich in native* iron. But to this Lesley projicrly objects that such secondary deposits would be conglomeritic and also contain metallic iron.

14. *Coneentration ami metamorphism of iron sand*.* This theory, proposed In 1874 by B. J. Harrington, Mr. Julien advocate* at considerable length, closing as follows:

"No concentration of titanic acid has ever been found in limoiiites or l>og-ores. These facts seem significant of the insufficiency of any chemical theory to account for the origin of all the iron-ores. In conclusion, it may be inferred that the mode of gen- esis of a bed of magnetic iron-ore may be determined with some probability by the following diagnosis:

When the ore retains structural characteristics allied to those of limonlte. or en- closes masses of hematite, a chcmieo-organlc origin is probably indicated.

When the ore is exceptionally free from phosphorus, or is rich in titanic or chromic add. or Is closely associated or mixed with granular garnet or olivine, a mechanical origin may be Inferred."

Karpingky, A. On the Origin of the Iron Ore of the Donetz Basin. (In Boorian). Rep. Runs. Qeol. Com., vol. I, pp. 1-12, 1883.

Mr. Julien has here evidently mistaken the literal translation of the term lake- (BJomalm) for the name of a supposed writer on the subject. Ed.

296 Bulletin No. Vl

Karsten, C. J. B. Ueber feuer-metteore. Acad. Sci. Berlin. Jan. 18,

Quoted by Lesley Id Iron Mfrs. Guide, p. 343. "Many a meteor may have been so oxidized while lying oountlass ages on the surface of the earth as to have lost its origi- nal nature and form; and many a massive meteor, thrown off when the rind of its mother orb burst on cooling, and Itself reaching the earth so quickly that its heat was still very great, may have ooolded under the action of the atmosherlc oxygen into a very different body from what it was in space. Man y a block of stone may lie on plain or mountain side among the earth-born rubbish of the cliff, without exciting a suspicion of its heavenly origin, as many a mind of the divinest mould lives unsuspected in a savage state or walks unrecognized among the crowds of city life. There may have been ages of its history when clouds of these meteors of both kinds met the earth, and spread themselves in blocks or masses or flattened layers on its surface. And if so, subsequent deposits must have covered them up, and denudation may have swept them away again or made sections of them, exposing their outcrops like terrestrial beds of rock or iron ore. The geologist at all events must be prepared to encounter oases of this kind."

"Such Karsten thinks to be the nature of the curious iron deposit near Thorn in Cen- tral Europe, discovered bv Herr G rod ski, of Wolfsmfihle, in 1862, and covering at least 700 acres of his ground, within four inches of the top of the soil. The ore outside was the common brown and yellow iron stone, but when freshly broken was peculiar of its kind, looking as if half melted, partly compact, partly porous, a black lava-like sub- stance, glassy and shaggy in its whole appearance. But the first steps of an analysis showed that it could have been no result of artificial smelting, mixed as the native iron was with an olivine mineral. The mixture of unchanged meteoric iron and metoric stone was so fine that when the mass was reduced to powder a magnet would not take up all the iron free of olivine. No iron works were ever heard of in the neigh- borhood of Thorn, nor could a vast number of them ever have accomplished such a result. The ore overlies the whole area in bars or plates two or three feet long, three to six inches wide and two or three Inches thick, shoved against and between each other in one place where there is a ravine and water course for 170 feet of face, but elsewhere separated by greater or less spaces; all lie on sand and scarce one appears above the soil. Most of the meteors seem therefore to have fallen in the ravine, where the cubic contents of only half the mass as measured would amount to 4,800 cubic feet or 360 tons, and the whole mass as known in 1853 could not be less than 1,000 tons, the fall of which one mile further west would have destroyed the whole town of Wolfs- mfihle had it then existed and the tradition of the event would have been indelible from the oral or written history of the land. Thousands of tons of iron falling from miles of height upon a frozen earth must have Imitated an earthquake very well." "Following up the clew which Karsten finds for us in this meteor fall of Thorn, we reach the ground of a clear Judgment upon all so-called native iron masses that they may and therefore must be meteoric, for here are masses of pure iron ore certainly meteoric without cobalt or nickel, and here also are such masses in

J>rocess of passing into red oxide of Iron ore. Hence whenever a pure or native ron mass is found, by which must be carefully understood not pure iron ore, but pure iron—not pure oxide of iron whether specular or magnetic, but pure iron Itself— it mupt be held of heavenly origin, fallen recently, and already in the process of be- coming red earth. Hence the impossibility of finding meteors of pure iron embedded as fossils In the rocks of any but the most recent times." (Lesley loc. clt. p. 345.)

Kayser, E. A. Geological and Mining Report on the Etheridge Gold- field, N. Queensland. Queenslander, vol. x, n. ser. No. 11, p. 24. Includes notes on red and brown oxide of iron .

Keilhau, — . Gaea Norvegioa. Chrwtiania, 1838. vol. i. pp. 61, 73, 107, 109, 125. On Iron Ores of Norway.

K>mp, J*. F. A Brief Review of the Literature on Ore Deposits. School of Mines Quarterly. voL x, Nos. 1,2, 4; vol. xi., No. 4. 1888-90.

Kjerulf, T, and Tellet Dahll. Geology of the vicinity of ArendaL Neues Jahrb. f. Min. 1862. pp. 557-581.

Kendall, J. D. The Haematite deposits of Whitehaven and Furnees. ColL Guard, vol. xxviii, pp. 157, 230, 374, plan and 18 figs, in text. 1874.

"Examines the theories which have been imagined to account for the formation of the deposits, and dismisses that of the Igneous origin, believing that the haematite was originally deposited as carbonate, partly replacing the limestone, and partly in pre- viously existing caverns. Thinks that the hsematite is younger than the Carbonifer- ous limestone, and older than a great part of the Permian." Oeol. Record. 1874. p. 372

. The Hsematite Deposits of Whitehaven and Furness, (with Discus- sum.) Tram. Manch. Oeol. Soc. vol. xiii , pp. 221, 286, 288, 304. 1875.

. Hsematite in the Silurians. Quart. Jour . Oeol . Soc. vol. xxxii, pp.

180-183. 1876.

-. On the Haematite Deposits of West Cumberland. Trans. N. Engl

Inst. Eng. vol xxviii., pp. 107-154, pis. xviii-xxxiii.; Discussion, pp. 219-!

ngi- 23*.

Iron Obes Of Minnesota. 297

"It is concluded that the ore has not always been deposited in cavities, but that it has taken the place of such parts of the rock as have been more easily affected by chemical action. Considers that the deposition of the ore is due to a ferriferous solu- tion depositing the iron as fast as it took up the limestone. The iron was derived from a volcanic source. This theory of the deposition of the ore being due to the replacement of the rock associated with the veins may be extended to the haematite deposits of other parts, as well as to many other metalliferous deposits, including those of Galena at Alston Moor." {Geol. Record.)

The Irn Ores of Antrim. Trans, N. of Engl Inst Eng., vol. xxx,

pp. 107-113. 1881.

Hematite Deposits of West Cumberland. (Supplementary Papers.)

Trans. N. of Engl. Inst Eng. vol. xxx, pp. 27-30. 1881.

. The Hffimatit* Deposits of Furness. Trans. N. of Enyl Inst. Eng

Yol. xxxi, pp. 211-238; Coll Guard, vol. xliv, p, 213. 1882.

Kern, Serius. On some recent discoveries of fields of Iron -ore in the South of Russia. Chem. News. vol. xxxiii, No. 842, p. 12. 1876.

Kerpely, Antal. [Hungarian Ironstone and Iron Trade.] Pp. 88; 4 tables, 2 pis. 4to. Budapest. 1877.

Killing, K. [Black Forest Gneiss, aud its relations to the Ore- veins.] Pp.80. 8vo. Wurtemberg. 1878.

Kimball, J P. and J. W. Foster. Geology and Metallurgy of the ores of Lake Superior. New York. 1865.

Kimball, Dr. James P. Am. Jour. Sci. (ii.) xxix, pp. 290-303. 1865.

. Am. Jour. Sci. (ii.) vol. 39, No. 117, May, 1865, p. 301.

"Beds of specular conglomerate are of frequent occurrence throughout the Iron re- gion of Northern Michigan, consisting of a paste of specular peroxyd of iron, through which are disseminated fragments of jasper, and rounded pebbles of specular iron ore which usually differ from the paste in texture, a difference very perceptible among ores of any one class even within narrow limits of distribution. These conglomerates not unfrequently resemble breccia In the angularity of the jasper fragments which they contain; but the pebbles of specular peroxyd, although sometimes obscure in a matrix of the same nature, commonly serve to indicate the detritul origin of these beds. That they are derived from local detritus Is evident from the fact that the jas- per fragments are not rounded, while the particles of softer specular iron ore are worn but slightly. They seem to be of littoral formation and to have been derived from dis- membered and crumbled deposits of successive lamina? of jasper and iron ore— similar to those deposits distinguishable In the bosses of the region. The specular conglomer- ate invariably exists under circumstances of true bedding and is traversed by paral- lel joints splitting the imbedded pebbles. It occurs Interstratificd with talcose and ar- gillaceous schists quite as regularly as the homogeneous ores. It will be ob- served that while the smal'er plications furnish the most available and complete evi- dences of the stratigraph leal conditions of the ferriferous schists, every exposure of them in quarries or natural outcrops, conveys the same character of evidence, but upon a scale far more extended, and generally requiring allowance for superficial vicissitudes, and a large degree of denudation Even if space permitted. 1 conceive It to be unnecessary to multiply instances of this evidence. It has been shown that the Iron ores of the Huronian series in Michigan an; essentially schists and heavy-bedded strata in which none of the phenomena of aqueous deposits formed by precipitation from water on the one nana, or by detritul accumulation on the other, are wanting. They exhibit not only stratification, anticlinal and synclinal folds, but are invariably traversed by systems of joints and at many points exhibit a perfect slaty cleavage. From a stratlgraphlcal point of view, while evidence Is elsewhere often ob- scure, the Huronian greenstone, schists and iron ores of Northern Michigan, in the ab- sence of close attention to their special chemical conditions, exhibit sedimentary and metamorphic phenomena adequate to render quite untenable. It is believed, the the- ory of the exotic character of any portion of them."

. Fossil Red Hematite Ore of Bedford Co., Peon. 1882.

. Geological Relations and Genesis of the Specular Iron Ores of San- tiago do Cuba. Am. Jour. Sci. (iii.) vol. xzviii, Deo. 1884. Considers vari- ous iron ores to have been formed in different ways as will appear from the fol- lowing quotations. One principal origin for iron ore in Cuba is said to be by chemical substitution of ferric oxide for the carbonate of lime in coralline limestones:

"Proof of the coralline parentage of the Iron ore bosses Is the preservation in near- ly all of them of fossil corals, or at least of oasts of coral. Such casts are found to- ward the outer parts of the ore bodies In what may be called their transition parts."

In a Paper upon the iron ore range of the Santiago district of Cuba read before the ins*. Jtfvfi. Ktu

*ng.. xlii. (1884 or 1885J, Prof. Kimball presents the same theory more at

Isngth and divides the ores of Cuba into three classes according to their mode of origin. "The large bodies of hematite or specular oxide, together with associated ferruginous

298 Bulletin No. Vi.

aggregates,— in part of magnetic oxide, are secondary products from the decomposi- tion or basic eruptive rocks." After describing in detail the process of weathering and alteration to which these rocks would naturally be subjected, and explaining the con- centration of ferric oxide, he adds: "The best of the iron ore bodies, including those of the East Mine and the developed ore-bodies of West Mine, hills, are mainly, if not Indeed wholly, replacements of coralline limestone." "The iron ore bodies of the alpine district east of Santiago, are exceptional from the fact that they are attributable to the immediate alteration of eruptive rocks, and that resulting residues, including an important portion of their original ferriferous contents, have been preserved almost in situ.

The other great bodies of ferric oxide in North America, like the Huronian deposits of Michigan and Wisconsin, are similarly derived from the decomposition of highly, but less basic rocks of metamorphic and not of direct eruptive origin. Such stratified specular iron ore bodies are believed to owe their existence to the accumulation by precipitation of ferric oxide from basins of water receiving the drainage from such basic rocks. The source therefore of the Archaean crystalline, or so-called primary, Iron ores, including most deposits of magnetite, was basic rocks compara- tively poor in ferrous oxide and rich in earthy silicates." "The second type of ore referred to weathers in prismatic blocks and possesses the structure of dense trappean rocks, such as abound in the form of dykes both within the syenite and the altered overlying iron-bearing rocks. Ledges of this description are uniformly rich at exposed surfaces, and mo Is their detritus or float. Such occurrences are the result of the decomposition in situ of basic eruptivesby the dismemberment of silicates, fol- lowed by the concentration of ferric and magnetic oxides. This action is essentially superficial." "It will be perceived that, unlike the great Archaean deposits of specu- lar oxide, both classes of ore deposits above described have undergone a process of concentration without going through the intermediate stage of sedimentation. In other words they are products in the one case of the segregation of ferric oxide, in part from immediate sources; and in the other of alteration in situ of protoxide basic rocks by peroxidation of their most unstable base, namely, ferrous oxide."

The third class of iron ore deposits is intimately associated with an overflow of epi- dotic dforyte and its origin is not fully settled in Air. Kimball's mind.

. Siderite-basins of the Hudson River Epoch. Am. Jour. Scu (iii)

xl, p. 155. 1890.

"This remarkable series of ore-basins seem to owe their origin to depressions in an in-shore mud-bottom fed by waters from decomposing basic rocks. From such waters ferric oxide was precipitated along with mechanical sediments from the land and cal- careous sediments from the sea."

Kin ah an, G-. H. Notes on some of the Irish Crystalline Iron Ores* Proc. Roy. Dvb. Soc. vol. iv, part vi. 1884. pp 306-317.

He first states that the lodes and lenticular masses of the crystalline ores, as well as carbonates, "are due to the decomposition of organic matter and carbonic acid." He quotes Le Oonte in this connection. Further on in the same paper are advocated in a confused way the "infiltration," "Pyrites," Ascension" and "Sublimation" theories for various ores, and the reader is left in doubt as to which theory is really supposed to be the correct one.

Kindler, — . Poggendorff's Annalen der Physi* und Chemie, vol. xxxviii, p. 203. 1836.

Was the first to call attention to the effect of decaying vegetable matter upon the solubility of ferric hydrates.

Khig", W. and Foote, R. B. Mem. Oeol. Snr. India. 1865. Deals largely with the immense Iron ore deposits of India, which are said to be among the wonders of the world.

King: 8 ton, J*. T. Account of the Iron Mine at Hay tor, Devonshire. Phil. Mag. and Annals, n. s. vol. 3, No. 17. 1828. p. 359.

Kitchell, Dr. W. Annual Report on Geol. Sur. N. J. 1856.

"Having described the geological occurrence of magnetic iron ore in this district, we are led to consider its origin, and to refer it to the particular class of metalliferous de- posits to which it belongs— whether it is of aqueous or igneous origin— whether it oc- curs in the form of stratified or unstratifled deposits.

"That they cannot be referred to the unstratifled deposits appears evident from the facts stated In describing the different forms in which the ore occurs: nevertheless It has been maintained by some that they are true veins of igneous origin, which implies that they extend to an indefinite length and breadth, that they differ in character from the rock in which they are situated, and have been formed subsequent to it. Such deposits do not usually coincide with strike and dip of the strata in which they are inclosed, but generally cross the line of stratification and frequently send off branches of greater or lesser dimensions, at different angles from the main veins. The body of the vein is in most cases separated from the walls on either side by decomposed rock called selvage.

"It will be observed that none of these phenomena can be applied to the magnetic ore deposits of this district; nor can they De veins of segregation, which implies that the material of which they are composed has been eliminated or collected together from the surrounding rock by some chemical action. Such deposits are composed of a

Sangue. or materials different from the surrounding rock, and are very irregular In heir form. "Stratified deposits imply that they are included within sedimentary rocks, that they

Iron Ores Of Minnesota. 299

are of aqueous origin, and that they coincide in geological position and in the mode of formation with the rocks in which they are situated. From the facts that have al- ready been stated, they must be referred to this class of metalliferous deposits.

**Tnat the rocky formation of this district. Including the gneiss, the hornblende and mica schists, the magnetic iron ore, and the quartz-feldspathic rocks, arc of rn e tarn Or- phic origin then? can be but little doubt; consequently it is conceived that they were originally deposited by water in a horizontal position; that they are composed of materials derived from pre-existing rocks; and tney were subsequently disturbed in their position and altered by metamorphic agencies, which have caused them to as- sume their present form and position. The origin, therefore, of these deposits of mag- netic Iron ore is identical ana contemporaneous with the rocky strata in which they are inclosed." (Geol. of N. J. for 1868. p. 534. quoted from Annual Report, 1856.)

"Its ( Limonite) origin is undoubtedly from sulphides of iron in the adjacent gnelssio rooks, which by atmospheric agencies nave been converted into soluble sulphates, and these latter when in solution have, bv chemical reaction on the magnesian limestones, produced precipitates of the peroxide of iron, and solutions of sulphates of lime and magnesia. (Geol. X. J. 1868, p. 663.)

Kjerulf, Th. and I>ahl, Telle f. Neues Jahrb. f. Mineral 1862, p. 657.

Klaproth, — . On the Mineral and Ohemical History of the Fossils of Cornwall. 1787. Translated by Dr. I. G. Groesche.

Klein schmidt, —. Berg- u. Huttenm.Zeitung. 1869, p. 357 and 37a

Klemnetz, D, [Results of the expedition to the upper part of the Abak- tne and the. Altai.] Mem. Soc. giogr. See. de la Siberie de VOueat. xiii, livr. L Pp. 15-25, 55-56. 1886.

Klupfel, — . Berg- u. Huttenm. Zeitung. 1871, p. 22.

Koch, Fr. G..L. Kupfer- und Eisenerze am Lake Superior. Zeit. deut. Geol. Gesells., 1851, iii, 355-358.

— - . Studien des Gott. Vereins Bergm. Freunde. vi, 1-248. 1854. Mining Mag. New York, 1853, i, 261-268.

"The iron rocks he would consider as upheaved from great depths, or else to have suffered great metamorphlsm by the influence of Igneous masses. That they (the iron rooks) may be simply the quartz rock impregnated with oxide of iron is thought prob- able."

Kohler, W. Zum alter der Oberharzer Erzgftnge. Mitth. nat. Ver. Mojo, n. F. Bd. ii, p. 123. 1880.

Koenen, A. Von. Ueberdas alter d. Eisenerz von Hohenkirohen. Jfachricht.K. Ges. Wis*. Gottingen. 1883.

Krantz.— Karsteris Archiv., 1840, vol. xv., p. 347. On Iron Ores of Elba,

"The Iron-ore-deposit, occurring on Cape Calamita, rises, where most extended, to a height of 900 feet above the sea. The bed is mostly limonite, and iron-ochre, at the tturraoe, but at a slight depth passes Into specular iron. Large fragments, partly In Dlaoe, partly detached, designate the entire extent of the deposit, on whose southeast *lde native magnets are found near the sea. I observed, so far as was possible, that the magnetic iron forms a bed on the eastern limit of the iron -deposits. Von Cotta, Ore Deposits, p. 356.

Kr*snopol*ky, A. [General chart of Russia. Sheet 126. Geological researches on the western slope of the Urals. ) Mem Com. GtoL Vol. xi, Ho. L Pp. 1-484.

[Preliminary account of investigations made in 1885 on the western lope of the Urals.] Bull. Com. Giol. No. 6, pp. 263-281. 1886.

Krotov, P. [Geological investigations on the western slope of the Urals In the Districts of Solikamsk and Tsoherdyn.1 Mem. Com. Gtol. T. vi, pp. 1-684. 188a

Kraa*e, F. M. The Lai Lai Iron Ore Deposits. Ann. Rep. Ballaarat School Mines pp. 45-50. 1881.

Kudematflch, — . Jahrb. d. geolog. Reichsanst. 1852. p. 4. Iron Oie in the Eastern Alps.

KoJiaE. A. Handbuch der Geognosie. Freiberg. 1836.

Kusa, Henri. Note sur quelques gttes miDlraax des terrains oxfordiens isnr Page de la formation de fer spatbique d'Allevard. Bull. Soc. Set. nat. 8*d..B$t.f t. i, pp. 25-3*. 1882.

Sur les Alone de fer spathique du Canton d'Allevard. Bull. Soc.

Q4oL France, ser. 8, t. ix, p. 699. 1881.

0*1 3rLLETO SO. VL

"

"4 ll

' 1

1

t

M..

t

- i : - -iisJ. iui -erTaiJiiy ..if Lizuost all rhi* H;-.,:Llid

. :i-. . r-jti-riiMi M-:rii rjauiL' matter in anirierir -is :r. ruiii-

i ..I.-- i "lie inti :uiu'ni'>i:i.

:t--4' . i t:i.- .icr "iitirsaix pai:p'/t'ir' i.-k?-. That

... i-.i .im \ijsitiy"i admirabie trrar:s*. '"nit the fi"l-

- ' 1. 1. .n u.1 : ' V,Miiie lias -Iftei'teil titanium with zircon.

vu:.i: MouQtum in Camberland Co.. Penn.

- Hii.*. .Jaii-jhry. >7:3.

rt Meciacice it-uotaits -jf Nittany Valley, Pa.

ifep''i5 : .: .i tl j'M"s ; hvm: rook** approach a tfreen-

sdtih ;. i . .lf„ rli .nivijiTire** a -leiiinientary origin

4nflltrar"i ii: ..- i. r m-p.,i.'ii ieii:i.*:illy fr-jin the wali-nx.'ks: in a

word they i;-*- s, -. :,i- u-r-iry :iii-y .ir/ !jeis.' beds deposited, like

Mgnly cfturrp'i -i 'n-i. i.l uir primary irnaznetic and other?

completely of pep'vii*-- . pmi. .i-t it m t 'ss ruerm:\tu**ei.>f mud and saud. which when crystallized. .i. .:: in.1 siia;je .'L :\.Idpar, lorubieude. mica, quartz, etc., etc."

litsley, J- E- V. D'luvilliers. Report on the Cornwall Iron Ore Mines. Annual Report Geology of PennsylvHnia. 1885. pp. -491-570. Map aid plates. .

The Cornwall manner:'.' top. -iias* as sedimentary a formation as the brown -Mnatiteoreiaawesin orher parrs ilie staTe. and was like them originally a forma- in&'iC magneslan Umesti'ni' beds. s.>r-!- thick and hard, others very thin, laminated.

rftrUtdeaiUy acted upon by warer.

\mmm IhrAn Annate* d. Mines. 1S49, p. 241. Jle moires de la

i fk 9ancf . 1850- P- Iron Ores of France.

C The Iron Ores and Lignite of the Montgomery County Val- " Nirt. Set. Phil. 1877-79. pp 46%55.

Iron Ores Of Minnesota. 301

Therefore we conclude that both now and always iron-ore Is, and has been, accumu- lated by organic agency; again, that both now and always there are and have been. three conditions of Iron-ore. each associated with the absence or presence in smaller or larger quantities of changing organic matter: 1. It may be universally diffused as a coloring matter of rocks and soils, and unavailable for Industries; in this case there has been no organic matter to leach it out and accumulate it. 2. It may be accumu- lated as ferric oxide; in this case there has been organic matter only sufficient to do the work of accumulation, and was all consumed In doing that work. 3. It mav be accumulated as ferrous carbonate; in this case there is an excess of organic matter in the form of coal.

But, In any case, organic matter has been the agent; and. therefore, in this caso as In all other cases, iron-ore is the sign of organic matter, and the measure of the amount of organic matter consumed in its accumulation. There are. there fore.three signs of the previous existence of organisms used by geologists; they are coal, iron-ore and fossils,'*

Liehmann, J. O. Abhandluug von den Metallmuttern. Berlin. 1733.

Leithe, . In Kranz* Jahrb. f. d. Berg- u. Huttenm. 1852, p. 234.

Iron ore deposits in the Eastern Alps.

Leon, E De. The Mineral Resources of the Southern States of the American Union. Iron, vol. iv, pp. 674, 706. 1874.

Le Play. Compter Rendus. Oct. 1841. Considered the magnetic iron ores of Kijny Tagilsk of eruptive origin.

Lesley, J. P. Mont Alto Lignite. Amer. Phil. Soc . Mar. 1865.

Iron Manufacturers' Guide. Pp. xzxiv, 772, 1866.

Mr. Lesley discusses at length the various theories that have been advanced to ac- count for the origin of the various ores of iron. lie advocates strongly achemico-sed- imentary origin.

On p 334 he says: "Chemical action is now known to be a sufficient cause for the grandest met amorphic phenomena. Good geologists look upon mountains of granite or sienite no longer as upbursts of molten matter from tne interior of the planet, but as sedimentary rocks hardened and crystallized by gentle heat and acid water, and even regard veins of quartz as Infiltrations from above rather than ejec- tions from beneath. The occurrence of the preciou3 metals, copper, silver, lead and even gold is explained by many who are authorized to speak as a precipitation in crev- ices from overlying waters or as original deposits at the bottom or the ancient seas.

The prejudice Instilled by our familiarity with iron in a molten state has left it hith- erto an exception to this rule: as a prejudice in favor of the igneous origin of all me- tallic veins obliged geologists to adopt the theory of gaseous impregnation to explain "fahlbands" or rocks through which pyrites is disseminated. But such a prejudice cannot last. Evidence is accumulating year by year sufficient to remove all doubt of the common sedimentary origin of iron even under forms which once were universally accepted as volcanic.'*

On p. 357 Mr. Lesley remarks concerning theories which he quotes from Prof. J. D. Whitney: "It appears from the foregoing that Mr. Whitney accepts both the eruptive and sedimentary theories of the formation of the primary iron ores and applies the former to unknown invisible masses antecedent to and now deeply buried under all, even tho oldest rocks which appear upon the present surface; masses of far greater sice and depth than the greatest yet discovered proportionate to the greater scale of all volcanic action In that pre-azoic day, and offering their sides and tops to such erosion and solution as would of course happen in such unsettled times, and be suffici- ent forproduclng the vast sediments of Iron which have been taken for volcanic out- bursts of the molten metal. Rut there is a fatal difficulty in the way of this hypo- thesis. These ore-beds are not ttrfccias. Deposits of the kind imagined would be con- gbmeritic; blocks of pig iron would be seen scattered through strata of granite." [In reference to this criticism of Whitney by Lesley, Dr. Wadswortb remarks f Bui. Mus. Comp. Zool. Geo!. Her. 1, p. 13.) "Here, again, ho has entirely misunderstood Prof. Whit- ney's views, which were that the great masses of ore in the Lake Superior district were eruptive where they now are, and were never sedimentary deposits, while asso- ciated with and derived from them are the hreceiaUd and ctmalomeritic ores, as well as other sedimentary beds. If it is necessary, the pig iron can doubtless be found atOvi- fak. Dlsko, in the basalt "]

"The hypothesis halts precisely where a similar sedimentary hypothesis for theorigin of coal halts; it Is unable to explain the solid homogeneous outspread and evidently local character of the deposit. But setting this aside, it is a men) hypothesis. No such masses of cast iron have ever been seen in the world. The beautiful theory of Sir Humphrey Davy so charmingly explained and Illustrated by Sir Charles Lyell in the xxxill chapter of his Principles, according to which the metallic bases exist in purity in the molten nucleus of the earth, and at the crust are alternately oxidized and de- oxidized by the oxygen and hydrogen of the sea water and the air, giving rise to steam rwwure, earthquakes, volcanic lavas, pumice dust and gaseous exhalations, is perfect Its way; but ft does not help us to conclude that planetary masses of pure iron have ever been ejected through the crust.

When we remember bow many observers have pronounced the Missouri iron moun- tain solid masses of pure metal rising from the central regions of the earth In the shape of cones, thrusting their points through the crust precisely the same as men de- scribed the Mauch Chunk summit mine before the floor of that mineral horizontal bed Of coal was discovered and Its shape revealed— we may withhold for a while our un-

Suallfied assent to these descriptions and suspect that future research may modify lie appearances presented now. Rut even if they still continued to be well adjudged

302 Bulletin No. Vl

expressions of the possibility of volcanic iron they will not cease to be rare exceptions to the general rule, and therefore supporters only to that extent of the ejection theory. They will still leave the sedimentary theory all the ground it asks for innumerable beds of crystallized iron in metamorphic rocks; original productions at thp bottom of a sea; not subsequent segregations in fissures."

"It is not intended to deny that iron is involved in all volcanic operations, with sil- ica, alumina, lime, magnesia and other metallic oxides and non-metallic elements. On the contrary, no element is more universally present in the world, and therefore none can suffer a greater variety of contingencies and transformations. Iron appeared in the lavas of Etna during the eruption of 18S5 in two forms; the magnetic and the non-magnetic. The early lavas of that eruption were gray, much more crystalline and strongly magnetic. The later lavas were dark, with a glassy coating, and had no action upon the magnet. Both were found to contain nearly the same amount of iron. Both contained also phosphoric acid (14 and 2.2 per cent). But there is need of some strong counteracting prejudice in favor of a truer view of the primary so-called veins of iron against the old prejudice that every unexplainable appearance among strati- fied rocks must be an issue of red-hot or fluid mineral from some conjectural reservoir of volcanism underlying even the quietest portions of the earth-crust, a prejudice which lies at the bottom of men s credulity to the cunning miner's maxim, *It will improve as you go down.' "

On p. 370 Mr. Lesley continues in the same vein, speaking of experiments made by M. de Sanarmont: " All this goes to sustain the judgment of the eclectics who accept the igneous origin of lava rocks of every age and vet are disposed to acknowledge the in- creasing evidence in favor of the chemical and chemico-sediuientary origin of perhaps a majority of the silicious. dolomitic and metallic, and even a few of the tr achy tic and trappeau members of the earth's crust, and certainly of almost all the so-called primary iron ores. The red specular or primary red hematite beds of the St. Lawrence are confessedly sedimentary."

"Beds of carbonate of Iron have been considered the natural chemical iron precipi- tations of the ocean charged with river solutions of the sulphate. But iron deposited from sea water, when the water was charged with organic matter in ancient as in mod- ern days, must have fallen in the form of a peroxide, and must have been mixed with a sediment from river and ocean currents of a very varied mineral character, princi- pally silicate of alumina and carbonate of lime and magnesia."

On p. 376 Mr. Lesley says: " It is in these hypersthene Huronian strata just under- neath the Potsdam sandstone or the base of the ldwer Silurian palaeozoic rocks, that the great magnetic Iron ore beds of northern New York, sometimes charged with phos- phate of lime, appear, and always in the form of chemlco-sedimentary beds, never In the form of igneous veins."

Many more passages might bo quoted from Lesley's admirable treatise, but the fol- lowing will suffice: "The titanium in titaniferoua iron is no more evidence of the locally igneous origin of tltanif erous iron than nickel in a lump of Iron is of its mete- oric origin, nor as much; for Dr. Mazade of Venice has detected titanium with zircon, molybdenum, tin, tungsten, tantalum, cerium, yttrium, glucinium, nickel and cobalt in the mineral waters of Neyrac, in France. (Ann. Sci. Vis., Boston, 1853, p. 203;."

The Iron Ores of South Mountain in Cumberland Co., Penn.

Proc. Amer. Phil. Soc.% May, 1872, January, 1873. . Report on Brown Hematite deposits of Nittany Valley, Pa.

. Titaniferoua Iron Ore Belt, near Greensboro, N. C. Read before

the Am. Phil Soc. June, 1871. pp. 139-158.

Mr. Lesley says that the ores are in rocks similar to those which contain the tltan- if erous ores of Canada and Sweden; and that at times these rocks approach a green- stone or diorvte in appearance and composition. He advocates a sedimentary origin for these and all other primary ores of iron: "These ore-beds are not ore-veins, for they do not out through the rocks crosswise. They have no well-defined walls; they have no selvages; there is no gangue-rock different from the rocks on each side; they have, therefore, not been formed in crevices subsequently in a later age after the up- tilting of the formation; they have neither been ejected volcanically from below, nor infiltrated aqueously from above, nor secreted chemically from the wall-rocks: in a word they are not at all ' veins.' On the contrary they are 'beds,' beds deposited, like the rest of the rocks, in water; deposited in the same age with the rocks which hold them; are in fact rock-deposits highly charged with iron; and they differ from the rest of the rocks of the formation in no respect excepting this: That they are more

highly charged with iron In fact, all of our primary (magnetic and other)

iron ore beds obey this law. They are merely certain strata consisting more or less completely of peroxide of iron, with more or less Intermixture of mud and sand, which when crystallized, fell into the shape of feldspar, hornblende, mica, quartz, etc, oto."

Lesley, J. P. and E. V. D'lnvilliers. Report on the Cornwall Iron

Ore Mines. Annual Report Geology of Pennsylvania, 1885, pp. 491-570. Map

and plates.

"The Cornwall magnetic iron ore mass is as sedimentary a formation as the brown hematite ore masses in other parts of the state, and was like them originally a forma- tion of magnesian limestone beds, some thick and hard, others very thin, laminated, soft, and easily acted upon by water."

Lev allots . Annates d. Mines. 1849, p. 241. Mimoires de la

SociStS de Nancy, 1850. p. 810. On Iron Ores of France.

Lewis, H, C. The Iron Ores and Lignite of the Montgomery County Val- ley. Proc. Acad. Nat. Sci. Phil. 1877-79. pp. 46-65.

Iron Ores Of Minnesota. 303

Lewis, H. C. The Iron Ores of the Brandon Period. Proc. Amer. Assoc. vol. xix., pp. 427, 428, 1880.

. Proc. Acad. Nat. Set. Phil. 1880. In reference to the supposed

remnants of the red sandstone strata discussed by H. D. Rogers, says:

"Tfoe iron ores of this region belong probably to (our different geological ages, and may, therefore, be divided into four classes.

1. Oneisslc Ore. This ore, never found in the (Montgomery Go. ) valley, occurs in the gnelssic rocks of Chester county north of the Chester Valley, and has been formed in place from the altered gneiss. It dips with the gneiss, and is generally accompan- ied by scales of graphite. Prof. Rogers supposed that this ore belonged to isolated patches of Trfassic red sandstone. The writer, however, has not been able to con- firm his sections, nor to show the presence of any more recent formation than the gneiss.

2. Primal ore. The hydroraica slates which lie between the Potsdam sandstone and the limestone liberate, when decomposed, a rich limonite ore which is largely mined in portions of the valley. Although in very irregular beds, a steep dip can be recog- nized. It is perhaps derived from the decomposition of pyrite. This is probably the ore mined at Edge Hill.

3. Tertiary ore. This ore, associated with which are the deposits of lignite, plastic clay, kaolin, flresand, etc.. has been hitherto confounded either with the Primal ore or with the drift ore of the valley. In that part of the valley under discussion there are three distinct lines of outcrop of this ore, having nearly an E and W trend. A ridge of limestone separates two of these lines. The ore lies sometimes at a great depth, below a re-stratified, decomposed hydroraica slate. This latter formation is almost identical in appearance with the decomposed Primal slate in place at the edges of the valley, and has, therefore, been mistaken for it. The discovery of lignite below it proves its re-stratification in a later age. In many places shafts have been sunk over 100 feet without coming to the limestone. The ore originally derived either from the limestone or from the primal slates, appears to lie below the lignitic strata.

4. Drift ore. Besting often unconformably upon these last, and capping the eleva- tions throughout the valley, is a drift deposit of gravel and boulders, containing a workable iron ore. It appe its that there are strong grounds for assigning an upper Tertiary age to the drift ore and gravel of the Montgomery county valley.

Lewis, J. F. The Hematite Ore Mines and Blast Furnaces East of the Hudson River. Trans. Amer. Inst. Min. Eng. vol. v, pp. 216-235, 1877.

Liebnr, O. M. Berg. u. Huttenm. Zeitung. 1857, p. 241 and 386; and 1860, p. 9.

Lipoid, M. Jahrb. d. k. k. geol. Reichsanst. in Wien. 1858, p. 5. (Ver- handl); p. 246; 1863, p. 339.

. Jahrb. d. k. k. geol. Reichsanst. in Wien, 1862; 1863, p. 839. Sitz-

ungsber. p. 195; 1863, Abhandlungen, p. 427.

Litton. Dr. A. First and Second Annual Reports Geological Survey of Missouri, 1853, 1854.

Liverftldge, A. On the Goal and Iron Deposits at Wallerawang, N. S. Wales. Proc. Roy. Soc. N. 8. Wales.

Locke, John. Geology and Magnetism. Smithsonian Contributions. 1851, iii. Art. I., pp. 17-29.

JjORan, Wm. K. Remarks on the Mining Region of Lake Superior, and a Report on Mining Locations claimed on the Canadian Shores of the Lake. Montreal, 1847, 31 pp., maps.

. Qeol. Can. Rep. Prog. 1847-48, p. 60 et sea. 1846-47, pp.

5-46; 1849,51pp.

. Geology of Canada. Montreal, 1863, 983 pp. with atlas.

. Geology of Canada, Ottawa, 1866, 321 pp. Contains a Report on

Lake Superior by Thoe. Maofarlane.

Logan, Wm. E. and T. Sterry Hunt. A Sketch of the Geology of Canada, in Canada at the Paris Exhibition, 1855, pp. 411-454.

Lotti, B. [Geological Observations in Elba.] Boll. R. Com. aeol. Ital. ▼ii; pp. 403-410. 1876.

Low, Dr. J, Oarstone of West Norfolk. Proc. Brit. Assoc. Adv. Sci.

Luders, Zsitschr. d. d. geol. Qesellsch, 1854, voL vi, p. 510.

304 Bulletin No. Vi.

Lyell, Charles. New York Industrial Exhibition. Sir Charles Lyell's Special Report on the Geological, Topographical and Hydrographical Depart- ments. Blue Book, 1854, xxivi., 50 pp. Annates des Mines, 1864, (5,) vi, 1-83.

. Principles of Geology. Vol. ii, 508, 1872.

"Sources of boo iron-ore. At the bottom of peat masses there is sometimes found a cake, or pan, as it is termed, of oxide of iron, and the frequency of bog iron ore is fa- miliar to the mineralogist. The oak, which is so of ten dyed black in peat, owes its color to the same metal. From what source the iron is derived has often been a sub- ject of discussion, until the discoveries of Ehrenberg seem at length to have removed the difficulty. He had observed, in the marshes about Berlin, a substance of a deep ochre yellow passing into red, which covered the bottom of the ditches, and which after it had become dry after the evaporation of the water, appeared exactly like oxide of iron. Rut under the microscope it was found to consist of slender articulated threads or plates, partly siliceous and partly ferruginous, of a plant of simple struc- ture, QallioneUa ferruginea. of the family called Diatomaceae. There can be little doubt, therefore, that bog iron-ore consists of an aggregate of millions of these or- ganic bodies invisible to the naked eye."

Lyman, Benj. S. Geological Survey of Japan. Report on the Second Year's Progress of the Survey of the Oil-lands of Japan. Pp. iv., 67, 8vo. Tokei.

Contains descriptions of Iron Mines.

. On the Lower Silurian Brown Hematite beds of America.

Proc. A. A. A. S. 1867. pp. 114-117.

"There seems, indeed, to be nothing in these deposits to remove the impression made by the correspondence in position, by the solid bedding occasionally visible, and by the other characteristics of the Smyth County exposures, thai the iron ore was depos- ited in regular beds of greater or less extent and thickness at the same time as the other rocks and that they have been broken into fragments at their outcrops, and that these fragments of hard and heavy ore have accumulated in quantities of various ex- tent according to the lay of the ground, mixed with the loam that comes from the more thorough comminution or decomposition of the other softer rocks and of a portion of the ore itself. At two or three points in Virginia and Pennsylvania, lumps of carbonate of iron have been found mixed with this brown hematite, and this would go to show that the ore was originally deposited as a carbonate like the coal measure beds of carbonate of Iron, and has since been changed into brown hematite either in the solid bed or in the lumps scattered through the loam, a change that so often hap- pens with coal measure carbonates. The supposition some have enter- tained that these lumps of ore are derived from the percolation through the loam of water charged with iron dissolved out of the rocks that contained Iron in the form of Iron pyrites or otherwise, and that the lumps are therefore concretionary in origin, and the result of a segregation so thorough that it sometimes leaves white flay or sand in contact with the ore, has more than one difficulty. The lumps are commonly not of the shape of concretions, for these must be more or less rounded or nodular, as they are formed about centers, and they could never be irregularly angular. It would seem, rather, as if the effect of the percolation of the water in these deposits had been commonly to give a ferruginous covering and character (taken from the ore) to the materials of the loam when they came from rocks that did not have that char- actor."

Macadam, W. Ivisoo. Notice of Veins of Specular Iron Ore at Strachur, Argyllshire. Trans. Edin. Oeol. Soc, vol. iv, pt. i, pp. 95, 96. 1881.

Macfarlane, James. The Coal Regions of America, Pp. 700, maps. New York. 1875.

. Geologists' Travelling Hand-Book. New York, 187a 261 pp.

If acfarlane, Thomas. On the Primitive Formations in Norway and in Canada. Can. Nat. Geol., 1862; vii, 1-20, 113-128, 161-171.

Report on the Geology of Lake Superior. Oeol Canada, 1866; pp.

. On the Geological Formations of Lake Superior. Canadian Nat.

Geol, 1866-68; (2.) iii, 177-202, 241-257.

Maderspaeh, L. [Iron-ores of Telekee-Rudobanya.] Oesterr. Zeitsch. Berg. Hatty No 7, p, 72* 187a

. [Hungarian Iron-ore beds.] Budapest 1880.

Mallet, F. R. On the Geology and Mineral Resources of the Darjiling District and the Western Duaro. Mem. Oeol. Surv., Ind., vol. xi, 96 pp., 2 maps. 1875.

Iron Ores Of Minnesota. 305

On the Ferruginous Beds associated with the Basaltio Rocks of

North-eastern Ulster in relation to Indian Laterite. Rec. Qeol. Surv. Ind.f vol. xiv, pp. 139-148. 1881.

. On the Iron Ores and Subsidiary Materials for the Manufacture

of Iron in the North-eastern part of the Jabalpur District. Rec. Oeol Surv., IndL, vol. xvi, pp. 94-121. 188a

Mandelsloh, Count. Sur la Constitution Geologique de l'Alpe de Wurtemberg. 1884.

ManrosH, U. S. Notes on Goal and Iron in the State of Guerero, Mexico. Am. Jour. Sci., ii, xxxix, 1865, pp. 309-811. Note by J. D. Dana on p. 358.

Maasart, Alfred, [Metalliferous deposits of the district of Carthagena' Spain.] Ann. Soc. Oeol. Belg , t. ii, Memoires, pp. 58-107. 1875. Chapter iii is on the origin of the various deposits.

Mather, W. W. Third Annual Report, Geology of New York, 1839; pp.

"Magnetic oxide of Iron. This ore abounds in Putnam county . Several mines are al- ready wrought and many more are capable of exploration. They form masses in gneiss and nornblendlc gneiss rocks, which by casual examination would be called beds; but after a careful investigation of the facts, I think they may be called veins. Their course is parallel to the line of bearing of the strata, and they lie parallel to the layers of the rock, but by close examination, it is found that in several instances after continuing with this parallelism for a certain distance, the ore crosses a stratum of rock, and then resumes its parallelism, then crosses, obliquely, another, and so on. In other places where a great bed of the ore occurs at some depth,only a few small strips of ore penetrate through the super-incumbent mass to the surface, as if the rocks had been cracked asunder, and these small seams of ore had been forced up from the main mass below."

On page 111 he says: "On Slmewog hill, one-fourth of a mile south, the vein is from 3 to 20 feet thick, associated with similar rocks (gneiss and hornblendic gneiss) and with granite. It has been wrought on Slmewog hill from 30 to 60 feet or more in depth over a length of 300 to 400 yards. It is scarcely doubted, from the observations made, that this vein is at least two miles in length, with an average width of 6 feet. Its depth cannot be estimated, but it is presumed that the labor of ages could not exhaust It In depth, as the bottoms of such veins have never, in any country, been found."

"The Cold Spring and Patterson turnpike crosses this (Phillips,) vein of

iron ore near the crest of the mountain, about nine miles from Cold Spring landing. There is an opening near the road, and near this crossing, where some ore has oeen dug. Here the ore seems injected in little sheets, veins and beds through the gneiss rock, so as to form one-fourth to three-fourths of its mass through a horizontal thickness (as the strata are vertical) of 30 to 35 feet." p. 112. "About three- fourths of a mile 8. 8. W.

of this is tho Denney mine The ore seems to have been injected among

the rocks Most of the ore is very compact and pure, but some contains

hornblende. Much of the feldspathio rock contiguous to the vein is injected* with

thin veius of ore from one-eighth to one inch thick." "Contiguous to

this opening is another 30 feet deep to the water, with a sheet of rock 5 or 6 feet thick, between two divisions of the vein. The rocks on each side of the vein are more or less injected with thin veins of ore; from examining the locality, many suppose that the ore has been Injected into the cracks and crevices of the rock when broken up by some upheave." p. 114. Foot note. "The phenomena of the mines in many places induce toe idea of igneous injection, connected with a powerful upheaving force. The feld- spar is often pearly, wrinkled, and with few laminas. The appearance of hyalite, a mineral usually associated with volcanic and trap rocks; the apparent injection in thin veins among the seams and crevices of the rock; the appearance of the softening of the gneiss ana bending its layers like a flowing slag, seem to point to an igneous origin of this vein. It often has the appearance of a bed, and at other times of a vein ramifying from a main mass between the strata, and at other times cutting obliquely across them, but still having its outcrops parallel to the line of bearing."

Maton, I>r, Tour in the Western Countries. [England.] Geological Hap. 1797.

Maussier, . Note sur l'extension de la formation de mineral de fer

grains dans lavallle de la Saone et da Rhone. Compt. Rend. Soc. Industr, Min. St. Etienne for 1882, pp. 170-192, 1882.

Maw* Mr* George* On the disposition of Iron in Variegated Strata, Quart. Journ. Qeol. Soc. vol. xxiv, pt. iv, 1868.

"The direct solvent action of humic. ulmic. and other acids, the product of organic decomposition, appears a more probable agent of dissolution, and does not necessarily involve the reduction of tho sesquioxide to the protoxide. According to Hlschof (Chemical and Physical Geology, English edition, vol. 1, p. ) humic acid occurring in vegetable mould forms a compound with sesquioxide of iron soluble in 2300 parts of water, and orenlc acid a combination soluble. The formation of limooite or bog-iron- ore appears to be the result of such dissolution; it consists of sesquioxide of iron In eomblnatlon with variable amounts of humic acid (Dana's System of Mineralogy, p. IB, ifth edition). The aggregation of sesquioxide of Iron around roots may thus be Incidental to its temporary dissolution by the acids of organic decomposition."

Hbo

306 Bulletin No. Vi.

McCreath, A. 8. The Chemistry of Iron Ores. Journ. U. 8. Assoc. XJharcoal Iron Workers, vol. 2, No. 5, p. 255, 1881.

The Mineral Wealth of Virginia. Gives descriptions of iron ore

deposits and analyses of the ores.

. The Iron ores of the Valley of Virginia. Eng. Min. Journ. p. 334;

and Trans. Amer. Inst Min. Eng. vol. xii, pp. 17-26, 1884.

. and E . V. d'Invilliers. Comparison of some Southern Cokes

and Iron Ores. Trans. Am. Inst. Min. Eng. 1887, pp. 20.

McOracken, H. B. The State of Michigan, embracing sketohes of its History, Position, Resources and Industries. Lansing, 1826, pp. 48-69.

McTCellar, P*ter. Mining on the North Shore of Like Superior, pp. 26. Toronto, 1874.

McKenney, Thomas L. Sketches of a Tour to the Lakes. Baltimore, 1827, 493 pp. North Am. Review. 1827, xxv, 834-352.

Meade, Richard. Notices of the Iron Industries of Cornwall. Mining Journal, vol. xlvii, p. 239. 1877.

The Coal and Iron Industries of the United Kingdom. Lon-

don. 1881.

Medwedev, A. [The iron ores of Kriwoy-Rog.] Gazette des mines russes.

No. 21. 188a

"The author discusses the question of the probable deposition of this mineral in stratified or massive deposits, and arrives at the conclusion that the results of explo- rations so far give no definite solution of this problem."

[On the iron ores at Kriwoy-Rog.] Gazette des mines russes. No.

12, 1889.

Merrittt W. EL The Magnetic Iron Ores of Victoria County. Proc Canad. Inst, vol. 1, faso. 3. p. 261, 1882.

Meyer, A. On the Fossil Ores of Lycoming County. Proc. Ac. Nat. Sci. Philad. ser. 3, 1882, pt. 1, p. 50, 1882.

Mo**ller, V. [Useful minerals and mineral waters of the Caucasus.] Mat. GSol. Caucase. Scrie ii, Livr. 3; pp. i-vi, 1-420, with a map, 1889.

Monroe, H. 8. The Mineral Wealth of Japan. Trans. Am. Inst. Min. Eng. vol. v, p. 236. Iron. vol. ix, pp. 74 and 234.

Moore, P. N. Report on the Iron Ores in the Vicinity of Cumberland Gap. Geol Surv. Kentucky. Pt. v, vol. iv, Ser. 2. n. d. [1884?.]

"The structure of the ore, in most cases, indicates, beyond reasonable doubt, that it was originally a bed of fossiliferous limestone. The original limestone has been dis- solved and removed by the solutions which brought the iron and deposited it in the form and place of the limestone. The iron has probably been derived from the rocks

solved and removed bv the solutions which brought the iron and deposited it in the form and place of the limestone. The iron has probably been derived f r above, and has been gradually removed by a process of leaching."

Moore, Ralph. On Coal and Ironstone Mining in Scotland. Proc 8. Wales Inst, of Eng. vol. iii, 1864.

Moro, Liazzaro. [On the Marine Bodies which are found in the Moun- tains] 1740.

"On the third day," he said," the globe was every where covered to the same depth by fresh water: and when it pleased the Supreme Being that the dry land should appear, volcanic explosions broke up the smooth and regular surface of the earth composed of primary rooks. These rose in mountain masses above the waves and allowed nulled metals and salts to ascend through Assures.." Lyell, Principles of Geology.

Moureal, L. N. [Geology of Central America.] Bol. Com. Map. GeoL Esparu t v, pp. 209-310, pi. C. [map.] 187a

Mugge, O. [Mineralogioal Notices.] N. Jahrb. vol. 1, pp. 231-251.

Mueller, . Die Eisenerzlagerstatten des obern Erzgebirges in Voigt-

landes. 1856.

Mueller, H. Berg- u. Huttenm. Zeitung. 1866, pp. 54, 160 and 185.

Iron Ores Of Minnesota. 307

Mueller, Prof. Albrecht, Die Erzgange. Sohweighausersiohe Ver- lagsbuohhandlung. Basle. 1880.

Muoichdorfer, . Jahrb. d. geolog. Reichsanst. 1855. p. 619.

Befers to Iron Ore Deposits in the Crystalline Schists of the Eastern Alps.

Murchison, Sir Roderick. Geology of Russia and the Ural Moun- tains, pp. 370, 380, 1815. Considered the deposits of magnetite in the Urals to be of eruptive origin.

"When on the spot it seemed to us possible to account for the appearance presented

by this metallic accumulation, most of which is now but little solidified, either by supposing it to be of plutonio origin, and that, issuing from fissures on the hillside, ft haa flowed, when in a molten state, into the hollow where it lies, or that it was former-

ly a mass of sedimentary materials which had been altered and mineralized by heat and vapours, which, making use of parts of the surrounding limestone as a flux, had elaborated this metallic substance.

We have no hesitation In agreeing with our skillful ootemporary (Helmersen) who has so closely studied the rooks of Blagodat. that these great masses of iron ore have flowed into this depression from fissures in the adjacent hill, and that they have since been cut through by other dykes of similar matter. In our description of the Katoh- kanar we shall advance independent proof of the igneous origin of magnetic iron."

Siluria. London, 1854, 523 pp.

Murray, Alexander. North Shore of Lake Superior. Geol. Sur. Can., 1846-47, pp. 47-67.

Geology of Western Canada. Canad. Jour., 1854-55, [1,| iii, 27-29,

4&-G2, 73-76.

. Geological Survey of Newfoundland. Report of progress for the

year 1874 pp. 75-800. St. Johns. 1875.

Murray, James. A Comparative view of the Huttonian and Neptunian Systems of Geology. Edinburgh. 1802.

Murrish, John. Report on the Geological Survey of the Mineral Begions. Trans. Wise. Aar. Soc. 1872 73, pp. 469-494. Appendix to the Assembly Journals, Jan. 1873. pp. 32.

Mnshet, David. On the primary Ores of Iron. pp. 16. n. d. 1802 [?] Philos. Mag. [?]

Nauckhoff. G. [Iron in Ovifak Basalt, Greenland.] Min. Mitth. (Jahrb. fc-fc. QeoL Reich*. Bd. xxiv.) pp. 109-136. 1874.

Kallmann, Carl F. Lehrbuoh der Geognosie. Leipzig. 1872.

Neckar, Prof. . Proceedings of the Geological Society of London,

98th March, 1832, Vol. ii., p. 392; Jameson's Edinburgh New Philosophical Journal. 1883.

"Has deduced Inferences in favor of filling metalliferous veins by means of sublimation.*'

Philosophical Magazine, 1830. Advocates sublimation theory of

origin of metallio veins. (De La Beohe, Geol. of Cornwall, 1839, p. 385.)

Hess, Walter. The Government Experiments in Iron-making in India. OotL Guard. VoL xxx, p. 925. 1875.

Neumayr, M". TJeber das Alter der Salzgitterer Eisensteine. Zeitsehr. dsutmsh. geol Qes. Bd. xxxii, pp. 637, 638. 1880.

Newberry, J. S. Notes on the Surface Geology of the Basin of the Great Lakes. Proe. Bost. Soc. Nat. Hist, 1862, ix, 42-46 ; Ann. Lye. Nat. Hist, 1870, ix, 213-284.

— Iron Besouroes of the United States. International Review. H751 1875.

"On lake Superior it is now easy to see that the beds were once horizontal strata, deposited In conformity with many other stratified sediments, but they are folded tJM broken in such a way that their true nature was for a long while misunderstood. Btotke magnetic ores of the Alleghany belt, they were once considered eruptive; Nl the progress of modern science has shown that all the so-called Eozolc iron ores

like the sheets of iron ie Clinton ore and the

simply metamorphosed strata, once deposited horizontally like the sheets of iron now found In the unchanged Palseozolc rooks,— such as tn

-band' and 'clay-ironstone* of the coal measures."

308 Bulletin No. Vi.

Newberry, J. S The Genesis of our Iron Ores. School of Mines Quarterly. Nov. 1880. Speaking of the ores of the Laurentian and Huronian, says: These deposits of iron ore, which are frequently of enormous size, were once universally and are now exceptionally regarded as eruptive in character; but we shall endeavor to show that they are all of sedimentary origin. TJhe arguments in favor of this view are both negative and positive. First as has been stated, we have never found in any quarter of the globe masses of iron ore among the products of volcanic eruption, nor any disconnected with either metamorphosed or unchanged sedimentary rocks." He further says that the highest authorities in chemical geology are "agreed In regarding the deposits of ore which date back to more or less remote geological times, such as the hematites and magnetites of the Paleozoic and Archaean systems, as the effects of similar processes of accumulation (by the reducing action of organic matter upon ferric oxides, thus rendering them soluble, Ed.) subsequently changed physically and chemically by the agents which have met- amorphosed the associated rocks. Although we cannot correctly class iron among the organic deposits,— since but little of it has formed part of plant or animal tissue- organic matter is so distinctly a link in the chain of causes and effects by which accumulations of iron have been produced, that we are compelled to regard all iron ore deposits as the results of organic forces, and proof of the presence of animal or vegetable life as an accompaniment of their formation. Hence in the Laurentian and Huronian formations, formerly designated as the Azoic or lifeless rocks, where some of the greatest iron ore beds occur, the iron may be accepted as evidence of abundant life at the epoch of its deposition."

. The Origin and Classification of Ore Deposits. New York. 1880.

. The Iron Ores of Southern Utah. Amer. Nat. 1881. pp. 410-412.

. Genesis of Our Iron Ores. Eng. Min. Jour. Vol. xxi, p. 286. 1881.

. Trans. N. Y. Acad. Set, vol. iL 1882.

-. The Deposition of Ores. Eng. Min. Jour. VoL xxxviii, pp. 88-40.

Newcome, P. N. The Iron-fields of Sweden. Coll. Guard. VoL xlvi, p. 871. 1883.

Newton, H. On American Iron Ores Suitable for the Manufacture of Steel. Proc. Lye. Nat. Hist. N. York, ser, 2. No. 4, pp. 94-96. Abstract only. 1874. Annals. Vol. xi, No. 3.

. The Ores of Iron. Coll. Guard. Vol. xxxi, 1876. pp. 620-622,

660-662, 700-702. Trans. Am. Inst. Min. Eng. Vol. iii, pp. 360-391. 1875.

Nicholson, H. Alley ne. On the Geology of the Thunder Bay and Sha- bendowan Mining Districts on the North Shore of Lake Superior. Quart. Jour. Geol. Soc, 1873, xxix, 17-24.

On the Mining District on the North Shore of Lake Superior.

Trans. N. of Eng. Inst. Eng. Newcastle-on-Tyne. 1874-75, xxiv, 237-249.

Nidda, v. Krug. Karstens Archiv. Bd. ii, 1838, p. 14.

Noggerath, A. Neues Jahrb. f. Mineral. 1815, p. 513; Karsten's Archiv. 1842. Vol. xvi, pp. 472, 491, 515 ; Verhandl. d. Naturh. f. d. pr. Rheinl. u. Westf. 17 Jahrg. 1860, p. 64; Zeitschr. f. d. Berg- u. Hutten - u. Salinenw. im.preuss. Staate. 1863, vol. xi, p. 68.

NordeMelt, Tnorsten. Notes on Iron-ore Deposits at Naaverhaugen, near Bodoe, Norway. Journ. Iron and Steel Inst. pp. 149-155. 1876,

Nordensklold, Prof. A. E. Account of an Expedition to Greenland in the year 1870. Geol. Mag., July— Nov. 1872. Vol. ix, Decade I.

Nordenskiold thinks a large meteorite here fell into a molten basaltic out- flow. Pieces weighing 23, 9, and 8 tons were found on the island of Disco, at Ovifak. They lay on the shore between low and high tide. These pieces were brought to Europe by the Swedish Greenland expedition of 1872, under com- mand of Capt. Baron von Ober.*

Nordenstrom, O. G. On the importance of geological skill in discover- ing Ore-deposits. Geol. fdren. Stockholm FdrhandU Bdt. i, pp. 61-63. 1874.

"As an instance the arrangement of iron and copper ores at Atvidaberg is given, showing their relations to the country-rock, which consists of granite, gneiss, horn- blende-rock, mica-schist, and protogine-gneiss." Geol. Record 1874. p. 198.

Ibon Ores Of Minnesota. 309

. [Iron ore deposits of Algeria and of Bilbao in Spain.]

Jemkontorets Annaler. Bd. 33, pp. 351-382. 1878.

Under the following heads: I. The iron-ore deposits of Algeria ; a. Oro- graphies! and geological conditions; b. Mode of occurrence; c. Mode of min- ing; annual production. II. The iron-ore deposits at Bilbao. A geological and industrial map is given. Scale 1 to 2,400,000.

Norton, G. H. The Geology and Mineral Veins of the country around Shelve, Shropshire. Proc. Liverpool Oeol. Soc , Sept., 1869.

Odernheimer, . Das Berg, u Huttenw. im Herzogth. Nassau, ii,

P. 206.

Oldham, Dr. Memoirs Geological Surrey of India, iv, 155.

Op pel, v. Anleitung zur Mark9oheidekunst Dresden, 1749.

Orlol, R. [Geological and Mining Information on the U. Part of the Province of Paienoia. j Bol Com. Map Qeol. Espan. t. iii, pp. 257-276. 1876.

Osborn, H. S. Minerals, Mines and Mining, 188S.

Owen, Davil D. Preliminary Report on the Geological Survey of Wis- consin and Iowa. Senate Docs., 1st Seas. 30th Cong., 1847-48,ii, No. 2, pp. 160-

. Lake Superior. Report of a Geological Reoonnoissance of the Chip- pewa Land District of Wisconsin, etc. Senate Docs., 1st Sess. 30th Gong., 1847-48, vii, No. 57, 134 pp. Am. Jour. Set., 1850 (2), x, 1-12.

. Abstract of an Introduction to the Final Report of the Geological

Surveys made in Wisconsin, Iowa and Minnesota in the years 1847 48-49-50, containing a Synopsis of the Geological Features of the Country. Proc. Am. Assoc. Adv. Sou, 1851, v, 119-132.

. Report of a Geological Survey of Wisconsin, Iowa and Minnesota.

Philadelphia. 1852, 638 pp., with maps. Am. Jour Sci, 1853, zv, 296-299.

Palliser, John, and James Hector. Papers Relative to the Explora- tion of British North America. Blue Book, 1859, Sess. 2, xxii, 64 pp. with

Pankhurst, E. A. The Ores of Iron, 22nd Ann. Rep. Brighton Nat. Hist. Soc, pp. 147-152. 1875.

Parkin, Charles, On the Perran Iron Lode in Cornwall and the Mines in the District. Trans. N. Engl. Inst. Eng. vol. zzvii, pp. 131-140 pis. xv- xtHL 1879.

Ration, J. H. The Natural Resources of the United States, 1888.

John B. A Concise History of the Iron Manufacture of the American Colonies up to the Revolution, etc., pp. 282, map. Philadelphia.

Peohar, J. [Coal and Iron in all Countries.] (Grupp. 5. Class 43.) Ber- lin. 18.8.

Pechin, E. C. The Minerals of Southwestern Pennsylvania. Trans. Amer. Inst. Min. Eng., vol. iii, pp. 399-408. 1875.

Pellat. Bdm. [Freshwater Fossils in the Weaiden Iron-ores of the Bas- Boulonnak] Ball Soc Qiol France, 3 s6r. t. iii, pp. 642-643. 1876.

Percival, Dr. J. G. Geology of Connecticut, 1837. Refers the limonite to the oxidation in situ of the pyrite and other iron-bearing minerals in the " slate.

Report on the Iron of Washington and Dodge Counties, Wisconsin. Man! 13 mo. pp. 12. 1855.

Percy, John. The Iroa Ores of Great Britain. Mem. Oeol. Sur. Qt. Britain. PI i, pp. 97. London. 1856. Contains report of W. W. Smyth.

310 Bulletin No. Vi.

Prdonnet, . Ann. des Mines, 1828, vol. iii.

Discusses Hartz Iron Ores.

Peters, R, Berg. u. Huttenm. Zeitung, 1857, pp. 296-337.

Peters, . Berg. u. Huttenm, Zeitung, 1862, p. 269. Ref.

Petermann, . Mitth. 1871, h . ii, p. 46.

Petrowski, A, [Useful Minerals of the Province of Nijny-Novgorod.] Gazette du gouv. de Nyny-Novgorod. Nos. 6, 7, 8, 14. 1886.

Peyre, M. Note snr le gisement de fer carbonate1 de Palmesalade. [Dept Gard.] Bull. Soc. Ind. Min. St. Etienne, vol. xiii, pp. 5-32. 1884.

Phil If ps, J A. Treatise on ore Deposits, pp. 78-79 et sea 1884 . "Mr. B. W. Fox, after having ascertained the existence of electric currents In many of the metalliferous veins of Cornwall, suggested the probability of this force having acted on various metallic chlorides and sulphides dissolved in the waters traversing vein fissures in such a way as to determine the mode of the distribution of the ores therein. He also endeavored to account for the prevalence of an easterly and westerly direction in the principal lodes oi Cornwall by their position in relation to the earth s magnetism.

Weighty objections to this theory have, however, been pointed out by W. J. Hen wood and others, and observed facts appear to indicate that the general direction of veins differs so entirely in different mining districts that their course probably depends rather on lines of fracture produced by plutouic, volcanic or other agencies, than on the action of electric currents.

Under the head of "Deposits resulting from chemical action'*, Phillips ( 1. o. p. 14 ) puts the Bog and Lake ores of iron, and says: "In all cases it Is the result of the alteration of other mineral substances containing iron when acted upon by air, moisture or acids, and is, to a large extent, due to the oxidation of the pyrites, and to the action of car- bonic acid upon siderite, etc. The decomposition of various ferruginous minerals, such as mica, auglte and hornblende, also contributes largely to the formation of ores of this class. Attention was first called by Kindler to the Importance of the effects produced by decaying vegetable matter on the solubility of ferric hydrates (Poggendorff's Anndlen der Physik und C/iemie, vol. , 1830. p. 208.) He observed that where pine trees had been planted upon sand-hills in such a position that falls of sand were occasioned by the action of running water, the ferruginous and quartzose sand was rendered colourless around decaying roots, and that It became in the course of a few months as white as if it had been treated with an add. The action of a root one-sixth of an inch in diameter, whitens the sand to a distance of from one to two inches around it."

On p. 396 of Phillips' Treatise on Ore Deposits is more upon the subject of Lake ores: "Stapff is of the opinion (F. M. Stapff, Zeit. d. d. QettL Gesdlsch. vol. xviii, 1866. p. 86) that lake iron ore is formed in the same way as bog iron ore, and he points out that in the lake of Tisken near Falun, the water from the mine and from the slag heaps has deposited a bed of ochre extending over the entire bottom of the lake within a period of 600 years; this bed is in places above ten feet in thickness. Lake ores when first collected are blackish-gray, brownish, or greenish ochre-llke slimes; on hardening, however, little globular masses analogous to those of oolitic iron ore are often formed.

Ehrenberg (1836) first suggested that these ores are produced by certain infusoria, which build cells mainly composed of hydrated oxide of iron. The Gaitomclta ferruginea Is especially an industrious manufacturer, of iron ore by secretion from dilute iron solutions."

As to the manner of occurrence of limonite, Mr. Phillips says, (p. 404) with particular reference to the deposits in the Ural: "Brown hematite deposits occur under very varying conditions, namely:

1. In small irregular masses in pi u tonic rocks.

2. As beds in metamorphlc rocks.

3. In beds at the contact of the metamorphlc rocks with Silurian limestones.

4. In deposits at the contact of metamorphlc and pi u tonic rocks.

5. In accumulations in the lower horizons of the Silurian formation.

6. In beds in clayey sandstone of Carboniferous or Devonian age.

7. As accumulations in the form of nests in Silurian or Carboniferous.

8. As accumulations in alluvium."

Mr. Phillips speaks of beds and veins or lodes of magnetite in various places. On p. 437: "In Peninsular India the magnetic oxide occurs either in beds or veins In almost every region in which metamorphlc rooks prevail. ... In many cases these de- posits would appear not to be in the form of veins, but to occur as beds, in the same way as do the gneissoid and schistose rocks with which they are associated. Bedded magnetite is likewise known to occur in the submetamorphic or transition rocks; while, both in the metamorphlc and sub- metamorphlc series, considerable veins of limonite are found in fissures and along lines of fault."

On p. 248 is the following statement: "The iron deposits of Rancie* (France) occur in nearly vertical beds, one of which is so permeated by brown and red hematite, spathose Iron ore. and occasionally with oxide of manganese, that ore frequently becomes the prevailing material. The limestones are often much colored by oxide of iron, and are traversed by numerous veins of pure hematite containing druses lined with con- centric layers of brown and red oxide of iron. This bed, which has an average thick- ness of about six :y-flve feet, can be traced from the bottom of the mountain to Its summit, a height of 1,070 feet, while its inferior limit has never yet been reached. The parallelism of this formation with the surrounding strata caused them for a long time

Iron Ores Of Minnesota. 311

to be regarded as being of contemporary origin, but If. Dufrdnoy, who some years since examined this deposit, inclined to the opinion that the deposition of iron ores took place subsequently to that of the enclosing strata."

In reference to the deposits of hematite which in England fill cavities, and hollows in the Carboniferous, Mr. Phillips says (p. 164) that it seems probable that it was "origi- nally deposited in the form of carbonate of iron. It will be easy to conceive that, on a solution of this substance in water containing carbonic acid coming in contact with limestone, the carbonate of iron would be deposited, and its place in the solution oc- cupied by carbonate of lime. When the carbonate of iron had been thus formed, its change Into hematite was probably effected by a process somewhat analogous to that by which siderite is eo often seen to become converted into brown iron ore. That a portion at least of the hematite has replaced carbonate of lime becomes evident from the fact that numerous fossils of the Carboniferous limestone have been found in the ore, and that some of them have only been partially converted into oxide of iron.

It is somewhat difficult to conceive whence the iron forming such numerous ferru- ginous deposits could have been derived, but Mr. Kendall suggests the coal-measures as the probable source from which this metal originally came. He further remarks that it is well known that the sandstones and shales belonging to this formation con- tain a large percentage of iron; and as these rocks at one time probably overlaid the Carboniferous limestones of the hematite producing districts, he thinks it not im- probable that a large proportion of the iron in the limestones may be the result of the percolation of waters charged with carbonic acid gas, through superincumbent beds which have been since removed by denudation."

Speaking of the lake Superior district Mr. Phillips says, p. 580, 581: "The iron-bear- ing rooks of lake Superior correspond to the Huronian system of Canada, and consist of a series of extensively folded beds of diorite, quartzyte, chloritic schists, clay slates, mica schists, and graphitic shales, among which are intercalated extensive beds of several varieties of iron ore." The same authority also says, p. 582: " The princi- pal deposit of spathic iron ore in the United States is at Roxbury, Connecticut, where, In association with quartz, it occurs In a vein traversing gneiss.*

Phillips, William. On the Mines of Cornwall. Qeol. Trans.., vol. ii, ser.i, p. 110. 1814.

Plchler, — . Beitr&ge z. Qeognosie Tyrols, (2 series), 1869, p. 7. On Iron Ores of the Eastern Alps.

Pierce, Dr. Iron Ores of Staten Island. Am. Jour. Set.. I, p. 145.

Pie y Allue, Juan. Oriaderos metaliferous en la oaliza de Almeria. Beoista Minora, ser. C, vol. i, pp. 341-345. 1883.

Piatt, F. Report 2nd Penn. Survey. L. pp. 98-116. 1876.

Play fair, John. Illustrations of the Huttonian Theory of the Earth.

Edinburgh. 1802.

materials which fill mineral veins were melted by heat and forcibly injected, in that state, into the clefts and fissures of the strata. These fissures we must con- ceive to have arisen, not merely from the shrinking of the strata while they acquired hardness and solidity, but from the violence done to them when they were heaved up. and elevated in the manner which has already been explained." p. 61. "The large specimens of native iron found In Siberia and Peru, mentioned above, 9 51, are among toe moat curious facts in the natural history of metals. The metal is too perfect, and the masses too large, to have been melted in the furnaces or to have been transported by the machinery, of a rude people. The specimen in South America weighs 300 quintals, or about 15 tons, and is soft and malleable. (Phil. Trans. 1788, pp. 77188). The Siberian specimen, described by Pallas, is also very large; it is soft and nalleable, and full of round cavities, containing a substance which, on examination, has been found to be chrysolite. Now it is certainly quite Impossible that, in an artl- ioial fusion, so much chrysolite could have come by any means to be involved in the iron; bat. if the fusion was natural, and happened in a mineral vein, the iron and Obrysolite were both in their native place, and their meeting together has nothing In Hthat is inexplicable." p. 230.

Polll, Prof. Pietro. and Dr. Pantaleone Luchetti, [Iron Ores of the Bergamo Valleys.] Atti. Soc. Ital. 8ci. Nat.; vol xxii, p. 125. 1879.

Polosov, A. [Description of the iron ore deposit at Koutim on the Wfobera, district Toherdyn.] Mem. Soc. Natur. Oural, vol. xii, pp. 58 59.

Portlock, Geological Survey, Derry, p. 173. England.

Porter, John B. The iron ores ancf coals of Alabama, Georgia and TnmuwMnn Trans. Am. Inst Min. Eng.\ vol. 15, p. 189.

Posepny. F. Archiv Practische Geologie. 1880.

Poeepnv, . Johrb. d. k. k. qeol. ReiclisansU 1865, p. 183, (Verhandl);

1870, p. 19 (Verhandl); 1875. Verhandl, pp. 40, 70. Ref.

Potter. W. B. The Iron Ore Regions of Missouri. Jour. U. s. Assoc. Charcoal Iron Workers. Vol. 6, No. 1, pp. 23-40. 1885. An interesting and

312 Bulletin No. Vi.

valuable description of the iron ores and mines of Missouri in 1884. Contains many analyses and facts of interest.

Pouyaune, — . [Iron districts of QuelhassaJ Ann. Mines, ser. 7, t. ix, p. 81. 1876.

Preaubert, P. [Ancient Iron Mines and Silurian Books of Angers.] Bull Soc. Etud. Sci. Angers. 1876-77, pp. 15, 2 pis.

Prime, F. Jr. Limonite Deposits of the Great Valley. Am. Jour. Sci, (ii) vol ix, No. 54, p. 437, 1875. Trans. Am. Inst. Eng. 1875.

I have shown 'in the commencement of this paper that they (the strata containing the brown hematite deposits and assigned by Hunt to the Huron! an) are Calciferous slates or schists: and were the ores formed by the alteration of pyrites in situ, we should find kernels of iron-pyrite which had escaped alteration, especially in the deepest mines. This is not, however, the case. Prof. Lesley. (Report on the Brown Hematite deposits of the Nittany Valley) thinks the ores "were deposits in loco originali of the iron (as hydra ted peroxide) set free from the limestone or dol- omitic rocks during their gradual erosion and dissolution," agreeing in this respect with Dr. R. M. S. Jackson, who made the first geological survey of the Nittany valley ore beds in 1838 or 1839. The brown hematites were probably formed by the oxidation of iron pyrites, but the former are not in the same place that the latter were. My reasons for this assertion are two-fold. In the first place, the animal car- bon of the organisms, whose shells formed the enormous quantity of dolomite or limestone, exists in such quantities throughout the limestone as to color the rock, the zinc blende (of Friedensvflle) and the carbonate of iron a bluish-grey. This same car- bon would readily reduce the sulphate of iron carried into the ocean to iron pyrites. As a proof of this reduction I have only to mention that iron pyrite has been found in the mud of a pond.* Secondly, the great major. ty of the brown hematites which I have had analyzed, and they are many, contain a trace of sulphur usually not more than a few hundredths of a per cent. I have also found minute (almost microscopic) crystals of iron pyrite in much of the limestone where it is opened in quarries, and I have also seen in much of this same limestone, where weathered, minute cavities, which I have ascribed (perhaps erroneously) from their general appearance, to the de- composition of the pyrite. My objection to the original deposition of the car- bonate of iron, as such, in the Carboniferous epoch is three-fold. In the first place it should be uniformly distributed through the limestone and not confined merely to the horizon just above the damourite slates. Then there should not be even the trace (the few hundredths of a per cent) of sulphur in the brown hematites, which we so uni- formly find. And finally there seems to be a lack of cause, such as exists in the case of the carbonates of lime and magnesia. For these were secreted by the marine ani- mals to form their shells, etc.. which would not be the case with the carbonate of iron. "In conclusion, I would once more point to the fact that, whatever the origin of brown hematites may have been, the cause of their deposition, where they are now found, must have been the damourite slates."

. 2nd Geol. Sur. Penn. Report of Prog., 1875, DD., p. 52

Speaking of the origin of the Brown Hematites, says:

"The ore must then have been formed either from the decomposition of ferrous salts in situ (i. e., ferrous silicates or the carbonate), from the solution of the ferrous carbon- ate in the limestone and its redeposition in the damourite slates, or from the same re- action of the ferrous sulphate formed by the oxidation of pyrite. The presence of large quantities of quartz, forming strings and bands, associated with the brown hematite ores in the damourite slates, tends to show that a very large proportion of the iron has been originally deposited as a silicate, this being subsequently decomposed by the action of percolating waters containing air and carbonic acid in solution. On the other hand, the presence of carbonate of iron, as found at Barber's Mine, formerly also at I ronton and in the Saucon valley, would indicate that a portion of the brown hema- tite had either been originally deposited in the slates as carbonate of iron, or that by some reaction at present obscure (possibly the reaction of some potash salt), the car- bonate had been formed and deposited, and by subsequent oxidation converted to the hydrate. Finally the ferrous sulphate formed by oxidation of pyrite would react on any alkaline silicates present, and converting these into sulphates would itself be thrown down." In regard to the time at which this deposition took place, he says (1. c. p. 76k "The conviction has been rather forced upon the writer, that we have to dis- tinguish two periods (of glacial deposition, Ed.) The one when the glaciers, coming through the gaps of the Kittatinny mountain, and in places riding over its crest, came down to the South Mountain, bringing large quantities of detached rocks with them, excavating the slates and limestones in their course, and depositing in the lime- stone excavations thus made, clay, sand, bowlders and brown hematite. In this manner were probably formed those sporadic brown hematite deposits which we find scattered along the middle of the limestone valley, and which are so uncer- tain, both in their extent and quality. The second period is that of the retreating glaciers."

Proctor, Dr. Basalt in the north of Ireland, and its formation. York- shire Phil Soc. for 1874, p. 29.

Pryoe, Wm. Mineralogia Cornubiensis. 1778.

Gmelin, KranW Handbuch der Ohemie, tth ed., vol. ill, p. 333,

Iron Ores Of Minnesota. 313

Sketch of Cornwall, taken from Mineralogia Cornubiensis, Journal

des Mines, tome i, 3, p. 91. (An. ILL) 1795.

Pumpelly, R. Oeol. Sur. Mo. Preliminary Report on Iron Ores. p. 8, et seq. 1872.

. Geological Survey Missouri. Iron Ores and Goal Fields. New

York. 1873.

"Both the Archaean crystalline rocks and the Silurian strata have undergone im- mense changes in volume, and in other respects, under this long continued influence. The gradual removal of the soluble constituents has left important residuary deposits of such substances as were insoluble, especially in the Silurian strata, as clay, flint.

crystallized quartz, sulphuret of iron, galena, etc. The more conspicuous instances oi this kind among the pre-Silurian rocks are residuary occurrences of iron ore.

The formation of residuary deposits of iron ore, having their origin in the gradual removal of very resisting crystalline rocks, is one of the local results of this

weathering away and decomposition of the rock, and is well illustrated in the surface ore at Iron Mountain." (pp. 9, 10, loo. cit. )

. On PBeudomorphs of Chlorite after Garnet at the Spurr Mountain

Iron Mine, Lake Superior. Amer. Jour, ser. 3, vol. ix, pp. 17-21. 1875.

. Mining Industries of the U. S. Tenth Census Report, vol. xv, pp.

1025, 1886. Contains reports on: Iron Ores of the U. S. by R. Pumpelly, Notes on Samples of Iron Ore collected in various parts of the U. 8., by Ed. B Benton, Bayard T. Putnam, Bailey Willis,W. M. Chauvenet; and Methods of Analysis by A. A. Blair.

Mr. Pumpelly discusses in some detail the manner of occurrence of the principal Iron Ore deposits of the U. S., and inclines to accept a general sedi- mentary or ohemioo-sedimentary explanation of their origin.

. Johnson's Encyclopaedia. 1886. Vol. vi, p. 22.

Randall, . Geology of Shropshire and South Staffordshire. Coll.

OuarcL, voL xxxiv, p. 847. 1877. Bemarks on the Pennystone ironstone seam.

Bath, G. v. Verhandl. d. naturhi&t. Vereins d. pr. Rheinl. u. West/. 1864. pp. 89,92: Zeitschr. d. d. Oeol Oesellsch. 1870. vol. xxii, pp.702. 706 ; 1978. voL xxx, p. 556.

Berioht uber eine Oeol. Raise nach Ungarn. Bonn. 1877

pp. 9, 11, and la

Raymond, R W., The Spathic Iron Ores of the Hudson River. Trans. Amer. Inst. Min. Eng., vol. iv, pp. 889-343. 1876.

. Statistics of Mines and Mining in the States and Ter- ritories West of the Rocky Mts, Eighth Annual Re,x>rt. pp. x, 159, 8vo. Washington. 1877.

Reich, F. Notiz uber electrische Strome auf Erzgftngen. Pogg. Ann., xlviii, p. 287. 1839. Berg. u. Hattenm. Zeit. [3J, 342, 386. 1844.

Reid, James. On the Ironstone bands of East Kent, 20 Rep. E. Kent Nat Hist floe, p. 40. 1878.

Re lie, James H. Sale of Mineral Lands. Reports of Committees, 1845-46, lst8ec*. 29th Cong, iii, No. 591, 51 pp., with map, contains parts of Reports by Douglass Houghton and Chas. T. Jackson.

Rensch, H. H. [A. visit to the Titaniferous Iron (Ilmenite) mines at Sogndal, Norway J Oeol Fdren. Stockholm .Bd.iv, pp. 197-201, plate. 1878

The ore occurs in a massive labrador-stone, sometimes in vein-like streaks and pure.

Richardson, John. On Some Points of the Physical Geography of North America, in connection with its Geological Structure. Quart Jour. Oeol 8oe., 1856, vii, 212-215.

Richardson, Jas. Geology of Canada. Rep. Prog., 1873-4, p. 99.

RicfcettS, P. De P. Certain Ores from North Carolina. Trans. S. Y. 4*kiS(*,vol.ll,pp. 149, 150. 1883.

314 Bulletin No. Vi.

ftiemann . Zeitschr. f. d. Berg. Hutten u. Salinenwesen impreuss,

Staat 1862, Bd. 10, p. 2.

Rigaud, F. [Iron ore deposits of Haute Maine.] Ann. Mines, sir. 7, t- xiv, pp. 5-62. 1878.

RWot, Li. E. Voyage au lac Superieur. Annates des Mines, 1855, (5) vii, m-328; x, 50, 365. Mining Mag., 1856, (1,) vi, 2&-37, 99-106, 207-213, 414-418; vii, 249-255, 359-367; 1857, fx, 60,65.

Notices iron ores aDd gives analyses.

Rohb, Chas. Geology of Canada. Rep. Prog. 1873-4. p. 176.

Roemer, F. Geologie von Obersohlesien. 1870; Oeologie Oberschlesiens p. 531.

[Iron Ores of El Pedroso, Seville.] Zeitsch. deutsch. geol. Oes. Bd.

xxxvii, Heft. 1, pp. 63-69. 1875.

Robinson, C The Progress and Resources of New South Wales. Pp. 25, 8vo. Sydney.

Rogers, H. D. Report, Geology of Pennsylvania, 1840, p. 296.

"The origin of the deposits of bog ore of the region before us (The Tertiary) we can readily understand by adverting to the very ferruginous nature of nearly all the strata, both the green sand and the beds overlying it. The water, not only in the marl region proper, but throughout the adjacent tracts, contains very generally a consider- able quantity of the oxide of iron, which it procures In its passage through the upper strata. Upon coming into the open air it parts with the carbonic acid, the agent by which it is enabled to retain the oxide of iron in the dissolved state; this it quickly precipitates, and hence the accumulations of bog ore in all situations where the low grounds are entered by springs passing out of the more ferruginous beds of 'sand and clay." (Rep. Geol. N. J. 1868, p. 665.)j

. Mineralogv and Geology of Lake Superior. Proc. Bost.

Soc. Nat. Hist, 1846, ii, 124-125.

Geol.Penn. Vol. I, pp. 83-90. 1858.

"But the most conclusive proof of undulations in the gneiss, and one which accounts for the presence of these deposits of iron ore, is the occurrence at almost every dislo- cation of an insulated patch of the Mesozoic red sandstone. The iron ore usually rests in a cleft or deep narrow trough, confined between steeply dipping beds of gneiss, or a wall of granite on the one side, and moderately steep southeast dipping strata of the red

sandstone, within or behind which no ore is ever found, on the other"

"We may account for the existence of the outlying narrow belt of the red sandstone, and for the presence of the deep and rich deposits of hematite iron ore which they con- tain, and wnich have evidently been derived by percolation from their strata, by the long continued trickling of the surface water in the line of fracture." In reference to another series of Iron ore deposits, he says; "I would not, however, here wish to intimate that either of these two last mentioned deposits oan be recognized as occupying the line of fault in the strata in which we recognize the iron ore. It seems probable, indeed, that the western deposit is not connected with any synclinal trough in the rocks, but is the result of an extensive decomposition of very ferruginous beds of gneiss. Possibly, however, this part of the valley, like that at the Lewis mine, may once have been overspread by a narrow, thin capping of ferruginous red shale and red sandstone (of Mesozoic age.")

Speaking of the ore deposits found in troughs of the gneiss as a whole, he says in the same place: "A careful inspection of the ore and all the attendant phenomena dis- closed in these excavations, cannot fail to suggest the notion, that the (Mesozoic) red sandstone is the source of the iron ore, and that it has yielded it up by a process of filtrationTand percolation of the surface waters, by which it has been carried down into the cleft between the rocks, and left there to concrete."

Further on he speaks of the iron ore resting upon the red sandstone instead of under it. "In the Latschaw mine, the stratum of red sandstone seems to have been caught In a deep fracture in the gneiss, and greatly squeezed and crushed. The iron ore reposes on the slanting face of this compressed mass of sandstone and of shale, and is even dispersed or mingled through its fragmentary materials along the line of the fault. So crystalline is the red shale and sandstone, and so full of scales of segregated mica and plumbago, that the observer is sometimes at a loss to decide, from band specimens, whether the rock is really an altered sandstone or a variety of gneiss. . . . . At this pit (Jones' mine) there seems to be a line of fault in the strata, filled with fragments of gneiss, of intrusive white granite, and of highly altered crystalline red sandstone. The iron ore, in a crude and sandy state, is interspersed through this confused mass, which it serves more or less to cement. On the south side of the trench containing the ore, we meet, as usual, with steep strata of gneiss, and on the north side with southeast dipping beds of a rock which, from its highly crystalline condition, and its abounding in mica and in specular iron ore, greatly puzzles the observer to determine whether it also is gneiss, or a highly metamorphosed form of the argilla- ceous red sandstone."

Iron Orep Of Minnesota.

Rogers, H. D. Geol. Penn.. vol ii, p. 713f et. 8eq. 1858.

"The magnetic iron ore occurs only in the form of true veins of injection or genuine mineral lodes. Its veins very generally coincide approximately In direction and in- clination with the crystalline strata, between the layers of which they lie, yet this conformity is only partial, for when they are traced with close attention they ant oc- casionally found to intersect the strata for a short distance, and then resume their parallelism. These iron ores evidently reached the positions In which we thus find them while in a melted state, their intrusion being the result of an enormous subter- raneous force, rupturing the earth's crust in the direction of the strata, or in the planes of weakest cohesion, and pressing the liquid ore and other fused mineral matters into the open fissures. Where the rent has been at all irregular or splintery the vein which filled It is Interrupted or uneven, being In some places pinched to very narrow dimen- sions by the approximation of Its walls, in others dilating by their recession, and In many cases being split into two or more parallel branches by the Insertion of a wedge- shaped portion of one or other wall The oxide of iron, while the

whole mass of the vein was yet in a state of fusion and very fluid, would necessarily, from its greater relative weight, follow the lower wall of the fissure as it flowed to the surface, while the much lighter earthy minerals would float, as it were, upon the upper side of the ore, taking the position, with respect to the latter, of Its scoria or cinder. This would arise wherever the slope of the nssure was sufficient to give the force of gravity much com rol in the distribution of the materials; but in all cases of a perpen- dicular vein there would be no tendency in the heavier metallic portion to collect on one side rather than on another, and therefore it and the lighter mass would mingle

more conspicuously There are many veins which are not accompanied

by any separate body of granitic matter, but contain the felspar, hornblende or other minerals In much abundance, disseminated through the ore. These we ma)" imagine to nave acquired their solid state, at least in portions near the surface, where alone we can observe them, from a condition of imperfect fluidity, like that of the already half-chilled lava of some volcanic eruptions, which would effectually prevent the sep- aration of the heavier from the lighter constituents." On page 716 he says in speaking of "Penn's Mount Ore- vein":

*'In the district we are now describing, though not strictly within the gneiss itself. there is an Important vein of igneous iron-ore, which has been wrought for some years. It Is opened on Penn's Mount, about half a mile east of Reading.

"The vein apparently is injected conformably to the bedding of the primal white sandstone, ana the ore is not accompanied by any bounding wall of Igneous rock, but is in immediate contact with the sandstone Itself. The latter rock disintegrates quickly on exposure to the atmosphere, and develops Innumerable small grains of hornblende, which speckle the yellowish-grey sand. The ore-vein ranges from Read- ing Fair ground, a little south of east, dipping 45 degrees south. Its thickness Is seldom less than 18 inches, and has been as great as 28 feet. Under t his enlargement it does not appear to suffer In quality. Theoreitsctf is of the granitoid variety, highly crystalline, containing quartz and felspar, especially the latter, in great abundance: hornblende and apatite enter also Into Its composition."

Regarding the origin of the surface iron ores of the Primal series, Rogers says,

"Respecting the ultimate source of the oxides of iron and manganese, it Is to he sought In the ferruginous slates upon which the deposits repose. The loamy soil im- bedding the ore appears to have been derived from the disintegration of the' slate pre- viously collected In a fragmentary or even pulverized condition in the depressions of the surface. Under the action of the percolating rain and springs, these materials would be converted into a mere loam, and the oxide of iron set free. - Much of the iron has been originally in the condition of the sulphuret of iron, diffused in minute crys- tals through certain layers of the slate. The facility with which this mineral under- goes decomposition, and gives rise to hyd rated peroxide of iron upon (lie access of at- mospheric air and the rain water, is a fact familiar to chemists. This view of the origin of a part, at least, of the ore, accords with what is known concerning those slaty rooks which contain much sulphuret of iron.

"These regularly-bedded ores of the Surgent series are to be regarded as among the permanent constituent strata of the formation, and us having originated, with the other sedimentary materials, In the form of very extended but thin sheets of fer- ruginous matter, covering at successive epoch* the wide floor of the quiet Appalachian sea. Whence all the oxide of iron was derived which mingled with the earthy de- posits of clay, sand, carbonate of lime, and the fossils of these deposits, is a question Which the present state of research scarcely enables us to answer. Perhaps we are tat horlxed from a consideration of the physical changes which seem to have occurred St the close of the Mat Inal period, to refer its origin to a wide expanse of newly-up- imlsed land of Primal and Matlnal sediments, impregnated with a cerialu proj>ortlon Of ferruginous matter, and to suppose that these parts, freshly exposed to active ero- sion ana waste by atmospheric agents. In supplying a part, at least, of the materials Of the Surgent strata, contributed, by steady accumulation, a copious amount of the alts of iron In solution to the waters of the l/cant ocean. We have only to imagine. In the next place, the operation of certain well known chemical reactions, such, espe- cially, as would arise upon the sudden introduction of calcareous matter, to perceive S Sufficient cause for the extensive precipitation of a definite quantity of the iron in the form of the peroxide.

This explanation derives some countenance from the independent evidence af- forded.—by the more calcareous and fossiliferous nat ure of these ore-beds, compared With the strata which embrace them.— that the epochs of the deposition of the Iron ore were also the periods of the most copious supply of carbonate of lime.

"To this source we may ascribe, with some prohihility perhaps, a large port ion of the peroxide of Iron in these layers: but we must not overlook another' train of causes, operating since the elevation of the st rata, to contribute in certain situations an in- creased supply of this Ingredient. An enormous quantity of ferruginous matter, both In the shape of the sulphuret and peroxide of iron, is diffused through the substance of

316 Bulletin No. Vi.

the slates, shales and marls In contact with these layers of ore. and the Infiltrating! waters have probably conveyed some of this, chiefly In the condition of sulphate of iron, into the ore-bea, where the carbonate of lime of the fossils would convert it into the peroxide. That such has been the origin of a part of the iron in the "fossil if erous ore "of some localities, is indicated by the general richness of the ore in peroxide, in all situations where the position of the outcrop, the slope of the ground, and the thickness of the covering slate, are favorable to a copious infiltration of the surface- water," (1. c. p. 720).

Rogers, W. B. On the Origin and Accumulation of Proto-oarbonate of Iron in the Coal Measures generally. Annual of 8ci. Disc. 1857 ,pp. 314-318.

The carbonate of iron was produced by the reducing action of organic matter, undergoing changes when in contact with it in situ in tne rooks, and not in solution.

Geol. Penn., ii, pt ii, pp. 722, 729, 737. 1868.

Rogers , E. Iron Ores of South Wales. Mem. Qeol. Sur. Iron Ores of Great Britain, part iii, 8voM p. 91. 1861.

ftobde, J. G. On the Non-Meteoric Origin of the Masses of Metallic iron in the Basalt of Disko, in Greenland. Selected and translated from the origi- nal Danish paper of K. J. V. Steenstrup. Min. Mag.,, vol. i, no. v, p. 143.

"Gives objections to assigning a motoric origin for these iron masses, from the mode in which they occur in the rock. Describes the basalt, and shows from examination of a basalt from Assuk, on the Waigat, that native iron does sometimes occur in basalt.*' (Geological Record, 1878,)

Rom i neer, C. Geological Survey of Michigan, Upper Peninsula, 1878-80. Vol iv, pt. 1, Marquette Iron Region; pt. 2, Menominee Iron Region, 8vo. New York. Geol. Map, 1881.

Rogsler, B. Speculum metallurgist politissimum, oder hellpolierter Berg- bauspiegel. Dresden. 1700.

Roth, Justus* Allgemeine und Chemische Geologic.

Rothwel), Richard P. Alabama Goal and Iron. Trans. Amer. Inst. Min. Eng., vol. ii, pp. 144-158. Also Coll. Guard., vol. xxx, pp. 131. 132, 386.

Rottermund, Count <le. Report on the Exploration of Lakes Superior and Huron. Canada Legislative Assembly, 1856, 24 pp.; Cioad. Jour., 1856, (2,) i, 446-452.

Royal Commission (Ontario). Report on the mineral resources of On- tario, and measures for their development. Roy. octavo, pp. 566. Geol., map and illustrations, Toronto, 1890. The Commission consisted of John Charl- ton. (Chairman), Robert Bell, William Coe, William H. Merritt and Archibald Blue.

lCuffrier, W. H. Report on the Landed Property of the Buena Vista Company. Philadelphia. 1889.

On page 23 Mr. Ruff ner says: "The only material difference of opinion among geolo- gists as to the origin of the ores found in the slates is as to whether they were origin- ally deposited from solution in separate beds on the surface of the slates, whilst they still lay undisturbed on the bottom of the Potsdam ocean, or whether they were dif- fused chemically or mechanically through the mass of slaty material like other ele- ments, and subsequently gathered into beds after the sea-bottom was lifted into the air. According to the latter view, which is the more common, this aggregation of the particles of iron oxide was made possible by the decomposition of the whole body of slates. The slates originally contained large proportions of lime, potash. and soda, all of which are soluble in acidulated waters. As these elements were leached out and the slates gradually converted into clay, it is thought that the Iron was dissolved out by the same waters and deposited in beds or pockets when reaching some impervious layers or basins of clay. Neither this theory of the genesis of the ores nor any other that I have seen, reconciles all the facts."

Russell, I. C. Suba£rial decay of rocks, and origin of the red color of certain formations. U. 8. Geol. Survey; Bulletin, i\o. 52, pp. 22-23. 1889. Regards the red color as dne to residual clay and ferric oxide from the decay of the older rocks, drained from the land into the ocean at the time the red beds were being accumulated. Applies this theory particularly to the Newark sys- tem, and the Red Beds of the central part of North America; but does not ap- ply it to the associated iron ores, indeed does not mention the iron ores, the existence of which seems to furnish an extreme instance of the same phe- nomena, whatever may be the cause.

Ibon Ores Op Minnesota. 317

Rutfmann, Ferdinand 8. Notes on the Oology of the Tilly Foster Iron Mine. Trans. Am. Inst. Min. Eng.9 xv, pp. 79-90.

Safford, J. M. Geol. Reoonnoissance of Tennessee, 1856. Mentions iron ores in various localities, and in speaking of the "Western Iron Region," p. 49, says:

"We are Inclined to think that the ferruginous chert of this limestone has been the great source of the peroxyd of the ores. Liberated by its decomposition the iron oxyd, in some form or other, has permeated the loose leached masses, and has been finally left in the beds, veins, pots, pipes, etc., in which we now find it."

Geology of Tennessee, 1869. Refers to iron ores in many

places in this volnme, and though no particular chapter is devoted to a discus- sion of their origin, it is evident that he considers them to be the results of decomposition, oxidation and segregation, or of ordinary mechanical sedimen- tation. On p. 210 we read:

°4In Carter county, seven miles above Ellzabethton. on the west side of Stony creek, is a layer of massive hematite,* from one to two feet in thickness. The locality is known as the Cannon bank. The iron ore is regularly stratified, rests on a thin bed of conglomerate holding small pebbles, and has sandy shales above."

"At another locality. Sharp's bank, in Sullivan county, it occurs in a vein-like,

nearly vertical mass This mass of ore is associated with light gray

dolomite, of the uppermost part of the Knox group. The rocks dip at a high angle. The hematite most likely dips with them, not being a true vein intersecting the strata." (p. 222, 1. c.)

"I have been much Inclined to think that the principal and original source of the ore (llmonlte, p. 360) has been the ferruginous chert of the Lithostrotion bed. It has iron enough to color the soil characteristically red. The banks are centres at which, through the agency of chalybeate waters drawing their iron from the decomposing chert, the ore has accumulated." And again, p. 451: "It is an interesting fact point- ing to the origin of theHimonite in these oanks that localities are not within the coves In which the banks occur, where the limestones and dolomites contain disseminated grains of pyrite, blende and galena (galenite). Such is the case in Bompass cove, and at one point tne galena is so abundant as to have attracted notice as a 'lead mine.* We re led to infer from such facts that the llmonlte of the overbank. at another point in this cove, and the lead and zinc ores associated with it, are oxydized portions of the leached remains of limestone, which, like those above, originally contained pyrlte, blende and galena."

f Salter, J. W. Ironstones of the "North Crop." Mem. QeoL Sur. Iron Ores of Great Britain, pp. 219-236. 1862.

The carbonic acid generated by decomposition of the plants would readily unite as a bl-carbonate, with whatever iron were present in the water, and be precipitated, carbonate of iron, in the form of 'Ironstone'. "

Sandbersrer, F. Untersuchungen Qber Erzgftnge. Heft, i. 8vo. Wies- baden. Pp. 159. Ore-deposits and veins of Sohapbaoh, Black Forest, 7. 1882.

Abstracted in Eng. Min. Jour. March 7, 15, 22, 29, 1884, under the title Theories of the Formation of Mineral Veins."

Satisfied himself that the heavy metals oaour in fie silicates of crystalline looks of every geological age.

. Neues Jahrb. f. Mineral. 1867, p. 175.

Bandera, George U. Mineral Lands of Lake Superior. Senate Docs., Sod Bess. 28th Gong., 1844-45; viL, No. 117, pp. 8-9; xi, No. 175, pp. 8-14.

8anvafre, 15. Notice sur les minerals de fer du Lac Suplrieur. Ann, Mines. 7 se>. t viii 1875.

8aytsev, A. [Useful Minerals of the Province of Nijny-Novgorod.] Mat four Vapprtciation des sols du gouv. de Nijny-Novgorod. Livr. xiii, pp. 1-41

8cbeerer, . LeonharcTs Jahrb. 1843. p. 631. Iron Ores of Aren-

dal, Norway.

8belle9 C. J. van. [Occurrence of Ores of Iron and Copper near Pan- hlgaaan, Sumatra.] Jahrb. Mijn. Ned. O.—Ind. vol. 1, p. 3. 1877.

Schmidt, A. Berg. u. Huttenm. Zeitung. 1865. pp. 30, 31.

, Adolpb. Geology of Missouri, p. 94. 1872.

MThe deposits of specular ore in the porphyries of eastern Missouri, especially in St. franoofa and Iron counties, occur In the most varied sizes and shapes. There are very lain deposits side by side with those scarcely workable. There are regular veins, as in Shepherd Mountain and Iron Mountain; there are regular beds, as in Pilot Knob In some localities east of it; there are irregular deposits, some of which approach

318 Bulletin No. Vi.

veins by their shape, as on Lewis Mountain, while others have proved to be isolated pockets, as on Hogan Mountain."

"1. It seems to me in the first place, that these deposits of specular ore, being all of a very similar mineralogical character, being all associated with the same kind of rock, and all situated within a small area of territory, must have been produced by one and the same kind of geological action, although the chemical action may have been differ- ent in different localities. The description of the various deposits which I shall give hereafter, will show the impossibility of supposing that the ores were injected in a melted condition. There is no sign of the action of very high heat on the associated rocks. All the inclosures found In the veins and beds of ore are of such a character that they would combine and melt in a very short time, when in contact with such large masses of melted ore. The ore is found in very thin fissures, of such an extent that a force capable of filling them with melted ore would certainly have opened the fissures, and would have produced thicker veins. Smelted and chilled ore has a very different appearance from that existing in these deposits.

2. A distillation could rather be thought possible. But distillations of iron-salts occur only in volcanoes, and are there mixed with other distilled matters, and never form large deposits. Here, on the contrary, the deposits are very extensive, the ore very pure, and neither lavas nor any other volcanic rocks are found in the ore re- gion, nor does the configuration of the ground indicate the former presence of any kind of volcanic action .

3. These specular-ore deposits cannot be derived from segregation, by waters pene- trating the adjacent porphyries, dissolving iron out of their mass, and depositing it in the fissures; for such an action would have altered these porphyries uniformly, along the veins and beds, which is not found to be the case. Such segregation could, besides, hardly have produced such immense deposits as Iron Mountain and Pilot Knob, and would certainly have caused a less uniform structure and frequently stalactitic forms.

4. The specular-ore deposits of eastern Missouri, therefore, must all have been formed by infiltration and precipitation from chalybeate or iron-bearing waters, sim- ilar to those which occur still in all parts of the world in the form of chalybeate springs, and are now forming ore deposits in numerous localities.

" All rocks of which the earth is composed are more or less penetrated by water; all are more or less broken or permeated by wide or narrow cracks and fissures; nearly all of them contain iron, some in very small, others in larger quantities. The iron can be dissolved and extracted from these rocks by certain solution&at certain temperatures. From the bottom of the sea. of the lakes, of the rivers, from the surface of the ground all over, waters continually filtrate Into the rocks below. These waters all contain more or less carbonic acid and other substances which they take up from the atmos- pheric air and from the soil. As they descend they dissolve various other matters under various circumstances, from the rocks througn which they flow. They follow the easiest and widest channels They grow warm, ami sometimes hot, partly by the natural warmth of the rocks, partly through the heat produced by chemical reactions. The higher temperature and the higher pressure increase their capacity for dissolving mineral matters, with which they become charged as much as the existing circum- stances allow. They may contain chlorides, sulphates, silicates, carbonates; they may contain silica, alumina, alkalies, lime; they may contain zinc, lead, iron, etc.

44 When these solutions have reached a sufficiently high temperature, and happen to find sufficiently easy channels upward, they will rise through such channels, driven by the pressure of the colder and therefore heavier solutions which follow them, and frequently assisted by the development of gases through chemical reactions. In this course upward they will again follow the preexisting natural channels, wide fissures, small cracks, Irregular holes and pockets. When they reach porous or loose strata, they will penetrate and impregnate them. When they come in contact with strata of materials which they are apt to decompose chemically at the existing temperature, they will alter, transform, metamorphose them. When these materials are such as to precipitate ox idea of metals from the solution, these oxides will be precipitated and ore deposits will be formed. The same effect must result when such metallic solutions approach the surface, where their pressure and temperature, and therefore their dis- solving capacity Is diminished or altered. to-

44 As the circulation of waters and watery solutions just described, although locally variable, has existed during the whole geological history of our globe, as it exists still, it is evident that the largest fissures and cavities, when kept filled with however dilute yet continuously renewed metallic solutions for hundreds and thousands of years, under otherwise favorable conditions, will finally become filled with deposits of ores.

44 It also appears evident from the above, that the same mineral solutions can, under different local conditions, produce very different kinds of deposits— veins in one place, pockets in another, beds in a third. I have no doubt that the various deposits of specular ore in porphyry, which I will now proceed to describe, were formed In this wise." ( 1. c. p. 97. )

Again (1. c. p. 116) he says: " Referring to this deposit ( Pilot Knob) specially, I fully agree with Professor Pumpelly, who by more detailed and more thorough investiga- tions, has come exactly to the same conclusion, namely, that it has been formed by a gradual replacement of stratified porphyry by ore, effected by solutions similar to those which deposited the ore in the Iron mountain and in the other places."

Speaking of specular ore in and on sandstone and limestone, Dr. Schmidt says (1. c. p. 126.) : 44 It seems that these specular ore deposits were originally formed in a lentic- ular shape, and imbedded in or on a sandstone containing layers of chert, and that they were afterward partially or wholly underwashed, some of the softer sandstone being thus removed, while the harder cherty parts and layers remained. Inconse- quence of this action, a slight shifting of the whole mass of ore may have taken place, which somewhat crushed and mixed some of the underlying materials, and brought the deposit In a more or less inclined position."

Speaking of limonlte deposits on limestone he says (1. c. p. 177): 4tThe solutions from which the ore was deposited have been infiltrated from above. The chemical influence

Iron Ores Of Minnesota 319

of the carbonate of lime has undoubtedly contributed, in no small extent, to precipi- tate and deposit tbe iron in the form of hydrated oxide."

"In some instances large caves, which are so common in all limestones, and which are undoubtedly formed by the dissolving action of acid waters, may have existed in the third magnesian limestone, below the ore-deposits, and may have caused either a

tradual or a sudden sinking, without which the origin of the pockets with almost ver- ieal walls, in which such deposits are sometimes found, cannot bo easily explained. The original lenticular masses of ore may have been formed either by deposition from chalybeate waters in depressions on the surface of the sandstone, and afterward cov- eredl>y other strata, and condensed and altered by pressure and higher temperature,or else they may have come into existence by a gradual replacement of lenticular lime- atone deposits formed in the above-described manner in the sand-stone."

Schmidt, Dr. Adolt. Iron Manufacture in Missouri. Trans. Ac. Sd., SL Louis, vol. iii, No. 3, pp. 261-272. 1876.

Structur der Spatheisenstein-Lageretatten bei Neuberg. Oesterr.

Zeitschr. Berg- Hutt, p. 480. 1880.

Schmidt, A. R. Berg-u Huttenm. Zeitung. 1866; p. 69, 97. ibid.

1867, p. 401, and 1870, p. 174.

— . Preliminary Notice of the Baltio Iron-ore Deposits. (In Rep. Buss. OeoL Com., vol. ii, pp. 107-122; out. 1883.

Schmidt, — Theorie d. Versohiebunger alterer Gauge. Frankfurt. 1810.

Schoolcraft, Henry R. "A view of the Lead Mines of Missouri, etc." Am. Jour. Sci. i, iii, 1821, pp. 59-72. New York, 1819, 8vo.

Narrative Journal of Travels Through the Northwestern Regions

of the United States, extending from Detroit through the Great Chain of Ajnerioan Lakes to the Sources of the Mississippi River. Albany, 1821, 419 pp., with map.

. Narrative of an Expedition through the Upper Mississippi to

Itasca Lake, the Actual Source of this River. New York, 1834, 307 pp. with map. Contains a Report by Douglass Houghton.

Schultz. — KarsterCs Arch., 1837, vol. iv, p. 229. Describes deposits of Iron Ores of the Harz.

Bcoresby, Rev. William. On the Uniform Permeability of all Known Substances to the Magnetic Influence, eta, pp. 50. 1832.

Seeland. F. [Huttenberg Iron-ores and their surrounding Rocks.] Jahrb. k.-k. geol. Retchs. Bd. xxvi, Heft. 1, pp. 49-112. 1876.

. [Manganese and Haematite Mines on the Kok. N. W. of

Uggowitz.] Verh. k.-k. geol. Retchs. pp. 36-37. 1878.

Senft, Dr. Ferdinand. Die Humus-, Marsch-, Torf- und Limonit- Bildungen als Erzeugungs-Mittel neuer Erdrinde-Lagen. 226 pp., 8vo. 1862. Leipzig.

Serlo, Albert. Leitfaden zur Bergbaukunde. Berlin. 1878.

Beys), Rev. John. On Native iron in Liberia. African Repository, June, 186L Annual of Scientific Discovery. 1856; p. 305.

Scaler, Prot. N. S The Economic Future of the new South. Arena, Vol. 2, No. & Aug. 1890; p. 267.

"The peculiar ease with which the southern iron ores are mined is in good part due to their geologic conditions. They are generally in the form of true beds which once were limestones, and have been converted by percolating waters containing iron in a dissolved form into iron ores."

Bharplet*, S. P. Note on Black-band Iron Ore in West Virginia. Trans. Am. Inst. Min. Eng., vol. z, p. 80. 1882.

Shepard, C. U. Report Geol. Sur. Conn., 1837: p. 13, et seq. Regards the deposit* of ore, both magnetite and limonite, which he has observed in Oooneotiout. as being in beds. In one place he says:

"The ore la included in gneiss and occurs on a low mountain, about one hundred and iftr feet above its base. The position of the bed is nearly vertical, its sides being well demned, and distant four feet. And again : "A more encouraging prospect for obtain- ing a supply of magnetic iron Is afforded in the northwestern corner of Winchester. WBtre a thin stratum of it was discovered upwards of forty years ago. It is contained

$Jd Bulletin No. Vi.

in gniss* and like the two last embraces chlorite.*' Under IAmonite he says in reference to some deposits of the ore mentioned previously: "The two first form beds of mica slate; the last in a micaceous gneiss and guartz rock. At Sharon and Salisbury, the ow is disposed In vast beds with a stratification everywhere obvious, and perfectly oonforaiaDle to that of the adjoining mica-slate."

"The origin of limonite in these rocks ('mica slate, micaceous gneiss or quartz rock') may be attributed to the decomposition of the sulphur© t of iron and other ferruginous tuiuerals with which they are known to abound. It is obvious also that, in a majority of instances, this change took place in the original repositories of these minerals, since no perceptible derangement is discoverable in the layers of the ore-bed, or want of conformity in them to the adjacent rock. This view, adding limestone to the rocks, has been found by Dana to accord fully with the various facts in the limonite region of western Connecticut and Massachusetts." Amer. Jour. SoL, (ill.) Vol. IX.,. No 54, p. 437,1875.

Sibirtzev, N. [Preliminary account of Geological researches made in 1887.1 Bull Com. Qtol. No. 3, pp. 95-107. 1888. St. Petersburg.

''Considers iron ore to be formed by change of Permian and Carboniferous lime- stone."

. [South-eastern part of Sheet 72 of the Geological map of

Russia.] Bull Com. Qiol No. 2, pp. 43-52. 1889.

"Considers the iron ores to be the result of the replacement of carboniferous lime- stone."

Silliman, B. Am. Jour. Set. (iii). xxiv, p. 375. 1882.

On the Magnetites of Clifton. Trans. Am, Inst Min. Eng.

Vol. I, pp. 361-371.

Simmons, W. The Metallic Ores of Cornwall. Group L Tin, Copper, Iron and Lead. Proc. Liverpool Oeol. Soc, vol. iii. Pt. I. pp. 28-35. 1875.

Six, A. Sur l'origine et le mode de formation dee minerals de Fer liasi- ques. Ann. Soc. Oiol. Nord. t. x, p 121. 1883.

Sjogren, A. [The connection between the manner in which ores appear and the relative ages of the rocks in which they are found.] OeoL Foren. Stockholm ., Bd. iii, pp. 2-13.

"It is now generally accepted that the ores of Sweden form beds or ellipsoidal masses (lagerstockar), and cannot De classed as veins. The author arranges the Swedish iron-ores under the following heads:— Quartzose and felspathio ores, pyroxenic and hornblendic ores, manganesian and calcareous ores.

The ores of the first group are characterized by their striated appearance, by the percentage of quartz and felspar, by the presence of phosphorus in a greater or less degree (possibly owing to the felspar), by a total absence of minerals belonging to the augite or hornblende types, and by limestone beds. Apatite is occasionally present. These ores, which are seldom found in large quantities, consist of magnetite and hsBroatite.

The ores of the second group consist of magnetite, and are found together with malacolite. coccolite, hornblende, asbestos, talc, chlorite, garnet, serpentine, epldote or other varieties connected with these minerals. They are often richer, purer and more ductile than the others, contain but little phosphorus, and are usually fused without the aid of fluxes, yielding a good and strong iron.

The ores of the third group are principally distinguished by their manganiferous and calcareous character and the large quantity of sulphurous nutate which they often contain. Among the associated manganitlc minerals, the following chiefly occur:— Hausmannlte, rhodonite, manganese-spar and ruebelite. As a rule these are magnetic iron-ores.

In the author's opinion, these groups belong to different geological ages in the order above given, from the older to the newer— the first group occurring in connexion with pure gneisses, and the two others with euritic and felsitic rocks. (Halleflinta)," E. Erdmann, Oeol. Record, 1874, pp. 06. 07.

. [Occurrence of the Taberg Iron-ore deposit of Smaland, Sweden.]

Oeol. Foren, Stockholm Forhandl. Bd. iii, pp. 42-62. 1876.

The hill of ore is 420 Swedish feet high, 3,000 long, and 1,500 broad. It consists of an almost homogeneous eruptive rock, composed of olivine and magnetite, with grains of plagioclase, viridite and serpentine.

. Neues Jahrb. f. Mineral, p. 434. 1876.

Smith , C . On Bed Hematite. Coal and Iron Trades Gazette, p. 172, 1877.

. The distribution of Spathic Iron Ore. Journ. Iron and Steel Inst.

No. 12, pp. 152-165. 1874.

— . The Iron Ores of Sweden. Jour. Iron and Steel Inst No. 2, pp. 310319; Coll. Guard, vol. xxviii, p. 444. 1874

Smith, Dr. Eugene Geological Survey of Alabama. Report of Progress for 1874 Pp. 139. 8vo. Montgomery. 1875.

Iron Ores Of Minnesota. 321

. Iron Ores of Alabama. Proc. A.A.A.S., 1878, p. 246, et. seq.

'There seems to be very little doubt that the limestones and ohert of the Quebec Dolomite, and the Slliclous group of the sub-carboniferous formations, have by their disintegration furnished the Iron, for most of the ore occurs mingled with the sands, clays, broken masses of chert and other de* which have evidently come from the disintegration of oherty limestones. Nearly every hillock, upon the two formations mentioned, shows more or less of iron-ore as surface specimens, and many of the sandy clays have the deep red color due to the peroxide of iron. Where the iron has accum- ulated we have the ore banks.'1

"Whilst most of the limonltes found in our ore banks may have been formed long since, yet wherever a ferruginous solution from precipitation, evaporation or other cause, deposits its iron, we have the conditions of forming an ore of iron, limestone, ohert or other ore. It may be that even now, every rain that falls upon the ferru-

!;lnous, sandy clays, in which most of our limonltes are Imbedded, may help in the ormatlon of limonite which at some future day may be utilized in the blast furnace/

"Prof. Rafford, (Geol. Tennessee), is of the opinion that the source of the Iron may be looked for In the ferruginous chert, whilst the formation of the ore masses, as we now And them, has probably taken place at a comparatively recent date, perhaps subse-

auent to the time when the pebbles and sands, associated with much of the ore, were eposlted."

Smith, J. Li. [Native Iron of Greenland and the Basalt which contains it] Compt. Rend. i. lxxxvii, pp. 674-676; and, under slightly different title. Bull Soc. Min. France, No. 5, pp. 90-92. 187a

'Thinks that the iron Is of terrestrial origin, and probably a secondary product formed by the reducing action of the lignites and other organic matter which the basaltic dykes have penetrated."

Smitb, Josiab Iron Ore Requirements of Great Britain. Jour. U. S. Assoc. Charcoal Iron Workers, vol. 8, No. 4, pp. 251-258. 1889.

Sm*ck, Prof. J. C. The use of the Magnetic Needle in searching for Magnetic Iron Ore. Trans. Amer.Inst. Min. Eng. Vol. iv, pp. 353-856. Iron, n. s. vol. viii, p. 585. 1876.

. The Magnetic Iron Ores of New Jersey. Their Geographical

Distribution and Geological Occurrence.

Trans. Amer. Inst Min. Eng., vol. ii, pp. 314-326. 1875.

"The granitic rocks that contain magnetite generally cut the beds of gneiss, and are huge ore-bearing dykes. Being contemporaneous with the gnelssold rooks, the ore- beds have been subject to the disturbing forces that have effected them."

First Report on the Iron Mines and Iron-Ore Districts

in the State of New York. Bull. N. Y. State Museum. 1889. 70 pp. with map

Rmytb,F. Wapringrton. Quart. Jour. Geol Soc. Vol. 15, pp. 105-109.

Regards iron ore deposits as occurring principally in veins, but partly also in beds. He says: "Oresof iron occur both in regular strata and in veins; the occurrence of a small vein on the east side of the hill, coursing N. N. E.. is addi- tional evidence In favor of the true vein-character of these deposits, a series of parallel Assures have been opened in planes very nearly concordant with those of the general stratification, and have then been filled with carbonate of iron, some quarts, and fragments of the containing rock. Some of these, with the slates, have afterwards been subjected to various disturbances, the results of which are seen In and slides, as at Ooosemoor near Hearlaud Wood, &c."

Smyth, W. W. Report on The Iron Ores of Great Britain. Mem. Geol 8*r. Gt Britain, p. 19. 1856.

There is little doubt that the brown ore is due to the decomposition effected by atmospheric or anoaenic action, and that It was all originally placed in situ in the con- dition of a carbonate."

Iron Ores of the Shropshire Coal Field, and of North Staf-

fordshire. Mem. Geol. Sur. Iron Ores of Great Britain. Fart iv, 8vo., pp. 60l 1802.

The Ores of Iron considered in their Geological relations.

OolL Guard., vol. xxix, pp. 787, 738. and Min. Journ.t vol. xlv, p. 550. 1875w Also Journ. Iron and Steel Inst, pp. 43-54. Iron, vol. v, p. 714.

Sokolov, K. [Description of the region embraced in Sheet 48, Geological map of Buafia.] Mem. Com. Geol, vol. ix, No. 1. pp. i-viii; 1-245. 1889.

Sorby, . On Cleveland Hill Ironstone. Proc. Geol. and Poly. Soc.

of the West Riding, p. 458. July, 1856.

Nature, xv, 49a 1887. Native Iron in the Basalt of Greenland.

322 Bulletin No. Vi.

Spencer, J. W. Economic Survey in Georgia and Alabama, throughout the belt traversed by the Macon and Birmingham railway, 86 pp., map. Athens, Qa. 1890.

Stahl, Geore Ernest. Specimen Becherianum. Leipzig. 1703. Pub- lished with Stain's edition of Beoher's Fhysica Subterranea.

. Treatise de Ortu Venarum Metalliferarum. 4to. Magdeburg.

Stabler, H. Berg- u. Huttenm. Zeitung. 1867, p. 17.

Stapff, F. M. Berg- u. Huttenm. Zeitung. 1868, p. 408.

. Berg- u. Euttenm. Zeitung. 1866, pp. 6, 18 and 29.

Stanard, B. A. Staoard's Bock. In the "Mineral Regions of Lake Su- perior," by J. Houghton, Jr., and T. W. Bristol, p. 81.

Stead, J, E. Phosphorus in Iron Ore and in Iron. Proc. Cleveland Inst. Eng. Sess. 1876-77.

Steavenson, A. L. Ironstone Mining in Cleveland. Journ. Iron Steel Inst. No. 2, 1874, pp. 329-337.

Steenstrup, K. J. T. [The Nordenskioldian iron masses and the occur- rence of native iron in basalt.] Vid. Medd. Nat. Foren. Kjobenhavn. No. 16- 19, pp. 284-306. 1875.

"Thinks that the large blocks of native iron which Nordenskiold discovered at Disko, North Greenland, are not meteorites, but that the iron belongs to the neigh- boring basalt."

Manual of the Natural History, Geology and Physios of Greenland and the neighboring regions; prepared for the use of the Arctic Expedition of 1875 edited by Prof. T. Rupert Jones. Pp. vi, 86 and xii, 783; maps, 8vo. London.

. [Nordenskiold's Iron Blocks, and the Occurrence of Native Iron

in Basalt] Vid. Nat. Foren, Kjobenhavn. 1875, pp. 284-306. 2 plates.

. [The Greenland Iron.] Zeitsch. deutsch. geol. Oes. Bd. xxviiL

Heft 2. pp. 225-233. 1876.

. On the Existence of Nickel iron, with Widmannstfltten's Figures

in the Basalt of North Greenland. (Translation.) Min. Mag. vol. vi, pp. 1-13.

Stein, B. Zeitschr. d. d. geol. Qesellsch. 1860. B. xii, p. 208. Berg- u. Huttenm. Zeitung, 1861, p. 177.

Stein, C. A. Neues Jahrb. f. Mineral. 1864, p. 490. Bef.

Stevens. Win. H. The Prospects of the Lake Superior Mining Region. Mining Mag. 1854, ii, 149-153.

Stewrt, Henry. Prospectus of the Cascade Iron Company. Philadel- phia, 1865, pp. 25, with map; contains also reports by Wm. Ferguson, Henry Merry, J. W. Ray, C. 0. Eddy, and others.

Stockton, John. Report on the mineral lands of Lake Superior. Senate Docs, 1844-45, 2d Bess 28th Cong., xi., No. 175, 22 pp., with map. Contains reports by Messrs. J. B. Campbell, Geo. N. Sanders, aud A. B. Gray.

S tod dart, W. W. Notes on the Metals found near Bristol. Proc. Bristol Nat. Soc. n. ser., vol. ii, pt. 1, pp. 68-76. 1877.

Strombeck, . Zeitschr. d. 1. geol. GeseUsch. Vol 9. 1857, p. 313.

Strombeck, A. V. Ueber die von Herrn Fox angestellten Untersuchun- gen in Bezug auf die eleotro-magnetischen Aeusserungen der Metallgfinga. Karsten's Archiv., vi., 431, 1833.

Btuckenberg, A. [Geological Sketch of the Iron works at Werkhne- Oufaleisky.] Mat QSol Kussie. Vol. xiii, pp. 49-34. 1889. "The third chapter gives a short account of iron ore deposits,"

Ibon Obb8 Of Minnesota. 323

Swank, Jas. M. History of the Manufacture of Iron in all Acres. Phila- delphia, 1884, pp. 428.

. A Bird's-Eye View of the Iron Ores of the United States.

Philadelphia, 1885. Am. Iron and Steel Assoc., pp. 81. Contained in Mineral Resources of the U. S., by A. Williams, Jr. 1885.

. Twenty-one years of Progress in the Manufacture of Iron

and Steel in the U. 8., contained in Mineral Resources of the U. &, by Williams, Jr. 1886.

. A Remarkable Year for the American Iron Trada In Mineral

Resources of the U. S.t by 1>. T. Day, 1887.

. The American Iron Industry from its beginning in 1619

to 1886. Contained in a Report on Mineral Resources of the U. 8., 1887, by Day. Am. Iron and Steel Assoc. 16 pp. 1887.

. The Iron and Steel Industries of the U. S. In Mineral Resources

of the U. S. 4 k1887-89, by D. T. Day.

b Sweet, E. T. Notes on the Geology of Northern Wisconsin. Trans. Wise Acad., 1875-76, iii, 40-55.

wlneford, A. P. History of the Lake Superior Iron District, its Mines and Furnaces. Marquette. 1871. 98 pp.

If . History and Review of the Copper, Iron, Silver, Slate and other

Material Interests of the South Shore of Lake Superior. Marquette. 1876.

Contains Geology of the Lake Superior Iron District, by C. & Wright, 132-

. Report of Commissioner of Mineral Statistics of Michigan. 1881

Iron Mines described on pp. 95-105*

Symonft, B. The Iron and Tin Deposits of Tuscany. Campiglia Mining District, 8vo. London. 188a

gzabo, Dr. Josef. [Eruptive Iron-bearing Rocks of Moravlcza.] Foldt XtaLvoLvi, 1876.

Tasche, Berg. u. Huttenrn. Zeitung. 1853, p. 209.

Tate, A. N. Notes on Ferruginous Bands in the Sandstones of this Dis- trict Trans. Liverpool Qeol. Soc, vol. ii, pp. 63, 64. 1882.

Tate, Ralph, and John Sinclair Holden. On the Iron Ores associated with basalts of the northeast of Ireland. Q. J. Q. &, Dec. 1869, vol xxvi Pt. L, p. 151.

Suggested Theories. — Four theories may be suggested to account for the

origin of the (pisolitio) iron ore ; these are:

(1) Sedimentary theory, which implies a derivative origin, but is at variance with the pttrologioal features— the distribution of the mineral particles has evidently been regulated by some other force than that of gravity. Mr. Du Nover, in a paper on the geology of Island Magee, read before the Natural History and Philosophical Society, Of Belfast. November 35, 1868, endeavored to demonstrate that the iron ore in the basalt Of Island Magee was entirely due to the action of water, 'that It was as true an aqueous conglomerate as If It had been formed in the heart of the Old lied Sandstone.' From this opinion we most emphatically dissent, though at the same time we fully concur with him when he assigns such an origin to the iron beds at Ballypalidy.

(D Theory of deposition. Implying either a precipitation of the ferruginous material from chemical solution, or segregation by organic agency. We believe that the state of combination of the oxides of iron, the intimate structure of the spheroids, and the petrology necessitate some other explanation.

(ft) Igneoue theory, Implying production by direct volcanic action. Though specular Iron Is enumerated among the minerals emitted from active volcanoes, and magnetite and Iron pyrites are accessory constituents of several of the basaltic strata, yet such an origin does not meet the requirements of the case in point. The distribution of the Spheroids of pisolitio ore demands either a shower of the ferrous nodules over a large ares- the smaller ones falling before the larger, or a flow of volcanic mud with sus- pended spheroids, the smaller sinking firm in the mass —both assumptions being highly

iQMetamorpMc theory. It Is omy by metamorphism that all the phenomena con- nected with the plsolltic ore can be Interpreted. By metamorphism we understand nothing more than the effects of heat, ana employ the term in its widest significance."

324 Bulletin No. Vi.

Taylor, John. Sketch of the History of Mining in Devon and Cornwall. Philosophical Mag., vol. v, pp. 357. 1799.

. On the Economy of the Mines in Cornwall and Devon. Qeol.

Trans , vol. ii, ser. 1, p. 309. 1814.

. Report on the State of Knowledge Respecting Mineral Veins.

Trans. Brit. Assoc. Adv. 8d. 1833. pp. 1-26.

Gives considerable attention to Werner and quotes his resume' of early theories of the formation of veins. Says that all who have preceded him have erred in attempt- ing to account for all metalliferous deposits upon some one hypothesis. He states that that there are three theories which may account for the formation of all veins.

1st. That which supposes them to have been open fissures, caused by disruption and occasioned principally by subsidence of parts of the rocks, which fissures were after- wards filled up with various matters by deposits from aqueous solution, chiefly from above. Modifications of this theory are: That such rents in the earth may have been caused in other ways, such as earthquakes or certain great convulsions, as well as by subsidence; that they may have been filled by infiltration of solutions, which depos- ited the substances with which they were charged in the veins, or by the process of sublimation from below.

2nd. That veins were formed subsequently to the consolidation of the rocks; but the cause principally assigned for such fissures is the violence done to the strata by the elevation or upheaving of other rocks from below. And it is an essential part of this theory that the materials which fill the veins were forcibly injected upwards in a state of complete fusion by heat.

3rd. Denying any subsequent processes which might either cause rents and fissures, or might fill them with matter which differs from the rocks which enclose them, the whole formation was contemporaneous with the rocks themselves, the mineral sub- stances which we find in veins having separated and arranged themselves into the forms in which we now find them to exist.

"That certain veins have been filled by Injection from below and with matter in Igneous fusion, seems to be rendered certain by evidence which is clearer than most we possess on such subjects, and must be admitted at once. Thus when we see a trap dyke traversing a bed of coal and charring the combustible matter, and affecting the rock itself with visible effects of great heat, we must assent to the cause assigned. . .

"The theory of the filling up of veins by precipitation from aqueous solutions is de- fective in not being able to show what Aenstruum could render such substances soluble in water; and this difficulty must remain an important one unless enlarged knowledge should hereafter afford the means of explaining it. . . .

"As we cannot easily conceive how the metallic ores can have been deposited from solution in water, and appearances are much against their having been injected in a state of fusion, there is another supposition which, though not free from difficulties, has yet probability enough in its favor to have gained many supporters— which is that these and some other substances have been raised from below by sublimation."

Thalen, R. [Discovery of Iron-ores by Magnetic Observations.] Nova Acta. R. Soc. Upsal. 4th centenary volume. 1877.

[Tracing Iron deposits by the Magnet.] Jemkonlerets Annaler,

n. ser. Jahrg. 34, pp. 17-124; and translated into German, "Untersuchung von Eisenerzfeldern durch m-ignetische Messungen," by K. Turley. 8vo. Leipzig.

. Revue dee Progres reoentes de l'Exploitation des Mines, etc., par

M. Ha ton de la Goupillilre, Ingen. en chef des Mines, etc. Ann. d. Mines, t. xvi., p. 6. 1879.

TMessing, Dr. J. [Mineral Processes of Switzerland.] Emul. Jurats. 1 ann., pp. 63-64. 1876.

Thirria and Lame. Memoire sur le Mine de Fer de la Voulte (depart- ment de 1' Ardeche.) Annates des Mines, 1820, v, 325.

Tholander, H. Experimental Researches on the Reduction of Iron Ore and on the effect of Roasting upon Magnetites and Haematites. Iron. n. s; vol. viii, pp. 418, 482. 1876.

Thomas, Richard. Report on a Survey of the Mining District of Corn- wall. Map and Sections, 1819.

Thnmson, Dr. M'neralogical Observations on Cornwall. Annals of Philosophy, vol ii, pp. 247, 346. 1813. w

Thoreld, A. F. [Have we any true Knowledge as to the Length of Time Necessary for the Generation of the Lake- and Bog ores? and if so, how long is this time?] Qeol For en. Stockholm . Bd. iii, pp. 20-40. 1876.

Ibon Obes Of Minnesota. 325

Tichborne, C. R. C. On the Occurrence of Magnetic Oxide of Iron at

Kilbriok, Go. Wicklow. Journ. R. Oeol. Soc Ireland, ser. 2, vol . iv.v pt 4, pp.

219-222. 1877.

"The ore occurs in an extensive vein running northwest and southeast. At the sur- face it is somewhat spongy, but becomes compact and dense as the depth increases. Although a magnetite, it contains excess of ferric oxide. The analysis shows it to oontain from 40.10 to 72.46 of magnetic oxide; thesp. gr. is 4.31. A quantity sent to Staffordshire has been smelted with good results. Considers that this vein is of aque- ous origin* but attributes the formation1 of the magnetic oxide to thermal influences underpressure on partially oxidized solutions. Describes laboratory experiments bearing out this point."

Tombeck, [Natural Fits in the Portlandian of Haute-Marne.] Bull

Soc Qtol, France, 3 se>. t iii, p. 554. 1876.

"Believes that at Sossa the pits in question were the mouths whence was ejected the Neooomlan iron of the neighborhood."

Torell. Prof. Otto. [Report on the Iron and Copper Ore Districts of Lapland, in Sweden.] pp. 144, 4to. Stockholm. 18/7.

"The iron-ore mountains of Lapland are inexhaustible treasuries. The ores, both magnetic and red iron-ore, occur in layers from 180 to 780 Swedish feet thick, and are followed to 1.400 feet in length.

Tornebohm, A. E. [Description of the Geological Map of the Filipetad Iron-ore District, Vermland, Sweden.] 8vo. Stockholm. 1877.

. [Geological Description of the Iron ore District of Persberg.]

Geological Survey of Sweden, Pp. 21; 13 figures in text, 4to. Stockholm. 1875.

. [Description to Geological Atlas of the Iron-ore Mines at Danne-

mora, Sweden.] Pp. x, 85; 2 plates (plans). 8vo. Stockholm. 1878.

Trebra, P. W. v. ErfahningenvonlnnernderGebirge. Dessau. 1785.

Trlbolet, M. F. de. [Siderolite Deposits near Neuohatel.] Bull. Soc. Bei. Nat NeuchateL t. xi, can, 1, pp. 24-31. 1877.

Trowbridge, C. A. Prospectus of the Marquette Iron Company. New York. 1864. 20 pp. with maps.

Tschermak, G. Der Meteoritenfund bei Ovifak im Gronland. Min. Mitt. Hefr. 8, pp. 165-174. 1874

Considers them of oosmic origin. "The meteorites of Ovifak In some respects re- semble the carbonaceous meteorites, though they differ from them in others, specially in the appearance of both metallic and rocky portions. They form a new type of meteoric rocks, and fill the gap that has separated the carbonaceous from other meteorites.** Geol. Record, 1874. p. 219.

. Neuee Jahrb. f. Mineral. 1867, p. 175; Mineral Mittheil. 1873,

p. 254.

. [Meteoric Iron of Greenland, etc.] Naturforscher. Nos. 49-52.

Tsohernov, D. [Description of the mines of the Urals and of the Expo- sition at Bkaterinbourg.j Journ. d. Minist. des Voice de Communication. No.

Contains some account of the mountains of magnetite at Wyssokaya and Blagodat.'*

Tscherngychev, Th. [A Geological Excursion to the Urals in 1888.] Butt. Com. Qtol No. 5, pp. 121-141. 1889.

MHe has made a detailed study of the structure of the Blagodat mountain, cele- brated for its mines of magnetite; the relations between this mineral and the sur- rounding rooks (porphyrltic granite and syenite) are exactly defined, as well as the eonditions under which magnetite Is produced and deposited.

. [Description of the central part of the Urals and the western slope.]

Com. Qiol Vol. iii. No 4; pp. i-viii; 1-320. 1889.

Tanner, — Jahrb. f. d. deterreich. Berg, u Huttenm. 1848-1846, pp.888; 1861, p. 91. Iron Ores of the Eastern Alps.

Tanner, P. Hitter von. [Metallurgy of Iron in the United States.] S pis. 8to. Vienna. 1877.

Tarley, B. Berg- u Huttenm. Zeitung. 1863, p. 348.

. Die Eiaenerz des Bergrevieres Norberg in Sohweden. Berg- hutt- *Z*tung. 1876.

326 Bulletin No. Vi.

Ulrich, F. Die Mineralvorkommnisse in der Umgegend von Goslar, 1890.

linger, — . EiDfluss d. Bodens. p. 39. On Iron Ores of the Eastern Alps.

Urbanek, — . Spatheisensteinvorkommen in Syenit bei Brunn. [Iron-ore in Syenite of Brunn.J Verh. not. Ver. Brunn, Bd. xiii, p. 35. 1875.

Vala, Jos., and R. Helmbacker [Irpn-ore between Prague and Berann.1 Arb. geol Abth. Land Bohm. 1 Theil 11, Bd. ii. Abtheil. pp. 99-407, 1874

Van dn Broeck, E. [On minerals of Iron in the Jurassic and Wealden of the Boolonnais.] Bull. Soc. Geol. France, s£r. 3, t. viii, pp. 616-619, 638-9,

Van Doren, .T. L. Prospectus of the Missouri Iron Company. Boston, 1837, pp. 40. Contains extracts from letters and reports by Schoolcraft, Featherstonbaugh, Dr. Newton May, John F. Cowan, Alphonso Wetmore, James Baily and others.

Van Hise, C. R. Am. Jour. Sci. (iii) vol. xxxvii. Jan. 1889. Holds same opinion in general as Irving, i. e. "that the iron formation deposits were origin- ally an impure cherty carbonate of iron/' p. 45.

Vanuxem, Lardner. Geology of the Third District, New York. 2d. An. Report. 1838, p. 268.

" In this series of rooks commence those beds of red oxide of iron which have long been worked in Oneida county. The number of beds varies from local causes. In Herkimer they are from one to two, in Oneida from one to three, depending, as I fully satisfied myself, upon the nature of the surface over which the iron flowed. If the sur- face was permeable the iron was absorbed by the mass, coloring the rook. If on the contrary, impermeable, a bed of ore was the result. On page 284 we find : Protean Group.— This mass is about two hundred feet in thickness, consists of green and blue shales, green, red and white sandstones, red oxide of Iron, gypsum, etc. The red sand- stone of Herkimer shows that the iron has passed through the rook by infiltration; much of it presenting its grains of sand enveloped by minute crystals of oligiste or specular Iron, the appearance which belongs to the red oxide when in a crystalline state."

Vennor, Henry Geological Survey of Canada. Rep. Prog. 1872-3. p. 175; 1874-75, pp. 112-122; 1876-77. p. 296.

Verbeek, It. D. M. West Coast of Sumatra, Verslag No. 11. [Iron-ores near Goenoeng-Bessi.] Jaarb. Mijn. Ned.O.-lnd. delL 1, p. 39, 1877".

Vicuna, G. [Iron in Biscay.] Rev. Min. s6r. B, t. 1, pp. 130, 137, 142,

Vieira, — . [Iron-ore deposit of Rancie\] Rev. Geol. t. xii, pp. 92-94.

Vinton, F. L. Leadville and the Iron Mines. Eng. Min. Journ. vol. xxvii, p. 110, 1879.

Virlet d' Aoust, T. Rapport sur les mines de fer oxyde" manganeaiffcre d'Escoumps (Pyrenees orientates), 4to. Pp. 12, 1882.

Vivian, W. M. Notes on a deposit of Iron-ore at Marbella, Province of Malaga, Spain. Proc. 8. Wales Inst. Eng., vol. xiv, pp. 48-52, 86, 1384.

Vogdes, A. W. Notes on the Distribution of Iron Ores in the United States. Ft. Monroe, Va. 1886.

Vigt, — . Bergbuukunst, 1789, 2 vols; Magazine d. Naturkunde, 1806, p. 478; MolVs Annalen, 1808, vol. vii., p. 174. Describes the Iron Ore deposits in the Thuringian Forest.

Von Cotta, Bernhard. The Geologist, p. 36, 1863.

Erzlagerstatten in Banat und Serbien. Vienna, 1864, p. 100.

Considered the iron ores of Banat igneous.

. A Treatise on Ore Deposits. Translated by Frederick Prime,

Jr. New York, 1869.

In this work the origin of iron ores is treated of in many places. On page

507 he save:

1 . Spathic iron forms lodes (or veins) bed* and bedded tcgrtQation*, in clay-slate, Zech- stein, etc.

Iron Ores Of Minnesota. 327

2. 8pherosiderite and clay-ironstone form beds, or lenticular masses, parallel to the foliation, in almost all deposits, and bituminous shales; also as grains, in an Eocene sandstone, on the northern edge of the Alps.

3. Magnetite, very frequently with somewhat of specular iron, chlorite amphibole, garnet, quarts ana numerous other minerals, forms beds, lodes, or veins, segregated masses and impregnations in crystalline schists, near their junctions with granular limestone, or of basic Igneous rocks.

4. Chromic iron, almost every where associated with serpentine or gabbro; a small admixture of chromic iron is probably never wanting in these rocks, but the same sometimes forms masses, segregations, or the filling of fissures in the same which can be mineo.

5. Specular iron, forms lodes in crystalline schists, and igneous rocks, even in lavas; at times associated with quartz, lievrite. etc. As beds of micaceous iron schist, between chloritlc schist, ltacolumite, or granular limestone, combined with quarts.

6. Hematite, compact, oohreous or fibrous, more rarely oollthic; frequently with ores of manganese, quartz, limestone or clay ; more rarely with carbonates, heavy and fluor-spar; forms beds, lodes and contact-segregations, for the most part in crystalline schists, or at leas tin old sedimentary formations; often at the limits of crystalline limestone, or also at the limits of pi u tonic igneous rocks, at the same time forming lodes in these; the hematite in the £rzgebirge appears to be principally associated with granite or quartz-porphyry.

7. iAmonite. compact, ochreous or fibrous; with the same accessory minerals as hematite, also under the same conditions of bedding, but extending into the most recent sedimentary strata: the accompanying limestone is as frequently compact as granular, the igneous rocks, at whose limits contact-deposits occur, are also volcanic, as for example, basalt."

It thus appears that he recognizee various methods of origin for iron ores.

As to the origin of ore-beds he remarks, p. 22:

"There can be no doubt that all true ore-beds were originally* formed by mechan- ical or chemical precipitation from water. Their condition may have been much ehanjred afterwards; thus under certain conditions hematite may nave been formed from limonlte, etc.; but their origin remains a precipitation. However certain this may be, still the origin of metalliferous portions of some of the beds remains unex- plained.

"Iron is a metal so widely distributed in its various forms, so common to all rocks, and held :n solution in so many springs, that the origin of the strata in which it pre- dominates, appears by no means obscure. On this account deposits of iron-stone only require an explanation of their state of aggregation and manner of occurrence in each particular case."

It thus appears that Von Cotta had in mind the germ of the theory which is advocated in this report, viz., the chemical precipitation of certain iron-ores contemporaneously with the formation of the beds of rock in which they are found. But in no place do we find him referring to any specific ore -deposit as having been precipitated in oceanic waters. On p. 546 he again advances the

same idea:

"True beds have evidently been formed in a manner analogous to that of the strata enclosing them, through mechanical or chemical precipitation from water. Limonltes are deposited before our very eyes on the earth's surface from ferruginous waters, from which beds of hematite and magnetite could be formed under the Influ- ence of heat and pressure; as well as from these latter beds, near the surface, limonlte might again be formed.

"The deposit of carbonate of iron is far more difficult to explain. For example, the

Shaeroslderites of various formations, or strata containing coal; since in the presence of e atmosphere, carbonate of iron is never precipitated from a carbonic-acid solution; bat, owing to the rapid decomposition of the same, always h yd rated peroxide of Iron. Only when covered (preventing the Influence of the atmosphere) can spharosiderlte, or spathic iron, be deposited. Therefore their formation in the depths of a vein-Assure is easily explained, but it will not apply to a bed at the surface; these were perhaps formed under a considerable depth of water.

"It appears to me. therefore, questionable whether these last named ores, where they occur as beds, were everywhere originally formed as such, or whether occasion- ally oxidized deposits have not first subsequently absorbed carbonic acid, . . . Just M compact limestone has l>ccn converted to marble, so could crystalline spathic Iron have been formed in an analogous manner from beds or masses of compact sphaeroslderlte-, through a subsequent crystallization of the mass, of course under the long continued effects of pressure, heat and moisture. Perhaps on this account beds of spa' hie iron are always found only in older deposits, never very recent ones.

"It Is an ascertained fact that limonlte is formed from spathic Iron, or sphierosld- erite, through the effects of atmospheric causes. Under other circumstances, beneath a considerable covering, hematite and magnetite appear to have been formed from the limonlte."

Von Cotta believed that veia* of iron ore can be and have been produced by other agencies than aqueous solution and deposition. On page 78 we find:

'It is further beyond a doubt that at times clefts in volcanoes are filled with sub- limed ores, especially specular iron, which was reduced from vapors of proto-chlorlde Of Iron. Lodes of specular or micaceous iron, and similarly many other lodes, may have been formed in the same manner at earlier periods In the history of the earth. We must also here know the special case before we arc able to form an opinion.

"It Is, also, by no means impossible that certain ores, coming in an igneous-fluid oondltlon, not from the central hearth of the igneous rocks, but from the; re-melting of the already existing metallic deposits, should have penetrated fissures and solidi- fied In them, although no cases of this kind arc known, as being formed at the present

328 Bulletin No. Vi.

time, or near the earth's surface. We are as yet too little acquainted in this relation with the results of highpressure."

He refers, on page 74, to the fact that Plattner proved the formatirn of mag- netite by sublimation in the Freiberg reverberatory furnaces, and refers to his

work, "Gangstudien," vol. II, p. 1.

On p. 01 he says: "That beds or impregnations of magnetic iron or specular iron were not originally deposited by water as such, is self-evident; but they are always and only found in metaniorphio rocks, as chlorite-schist, mica-schist, etc., and were subsequently subjected to the same catogene influences as the matter from which the rocks sprang. The peroxide of iron, and under certain circumstances the protoxide, might be formed from the hvd rated peroxide of iron. Similar events might have taken place in other metallic Beds, and the accompanying or Independently occurring ore-impregnations, which are found in crystalline schists. This circumstance may explain many otherwise unintelligible phenomena."

On the origin of Spathic iron we find still further considerations on p. 346. " The origin of these deposits (Erzberg) is still very enigmatical. In so far as they are true beds, the mineral matter composing them must have been deposited, during the Dev- onian period, between the beds enclosing them. But in what condition? Hardly as crystalline spathic iron. It might be supposed that they were formerly sphaarosiaer- ite, and had become crystalline through a long continuing period of pressure and warmth. Such a hypothesis would also allow the consideration that the neighboring veins of spathic iron had been pressed in a softened condition from the veins into the fissures. But where do such thick beds of sphserosiderlte occur? and, in any case, the manner in which the sphserosiderlte was formed still remains an unsolved problem."

On pp. 502, 50 is still further discussion on spathic iron, where ideas simi- lar to those quoted are advanced.

On p. 225 we find the following: "A perpendicular vein of magnetite. 30 feet broad, crops almost out to tbte surface, at the junction of the Silurian and Azoic slates, north- erly of the village of Glashfltten, in the lordship Badlutz.

The magnetic Iron ore is enclosed towards the surface, by llmonlte and hematite, with layers of slate: and is generally so intimately combined with the clay-slate that it might be called a clay-magnetite. It is a very remarkable fact that this ore, near the surface, attracts and is polar; at a depth of 14 feet it only repels, and at a depth of 30 feet is no longer magnetic. From this it would appear as if the magnetic force had first been excited by the Influence of the atmosphere."

On p. 182 he describes some deposits of iron ore very similar to some in the Lake Superior region.

" In the gray wacke rocks between Christgrtln and Stenn, near Zwickau, occurs a suc- cession of greenstones which are accompanied by iron ore deposits of a peculiar kind.

"As these deposits principally occur at the limits of the greenstones, they may be comprised under the general name of contact-deposits; though at times they are found altogether within the greenstones, or at some distance from them in the slates. Though clearly of a vein-like character, these deposits are distinguished from the iron lodes of the upper Erzgebirge and western Voigtland (occurring as true fissure lodes), not only by ine irregularity of their extent, as well as of their strike and dip; but also by the frequent absence of sal bands. The frequent transition of their matrix from llmonlte and hematite, either pure or somewhat deteriorated by intermixture with chlorite, quartz and calcspar. through more or less ferruginous greenstone or slate, into the totally barren country rock, shows a greater resemblance to certain classes of beds. They appear at times extending for a considerable distance in length and breadth forming vein-like masses several fathoms broad, at times following the

freenstone limits and slates in the most fantastic curves; at times occurring as road, bed-like zones, of extremely ferruginous Azoic or Silurian slate, between non- metalliferous layers of this rock; again as pockets or nests in the midst of decom- posed greenstone, which not seldom are of considerable breadth and extent. Near the surface their ore Is chiefly massive or earthy limonite with somewhat of goethite, or at greater depths these are replaced by hematite in various degrees of purity."

The formation of bog iron ore is spoken of on pp. 255-256, as follows:

"The formation of bog iron ore, where it is still going on, is very instructive. It is formed by deposits from water which frequently contain very small quantities of iron dissolved in it. The long continuation of the process of deposit, here, completely re- places a greater energy of action, and it is probably the same in the formation of many other ore deposits."

"The iron content of the water evidently originates in the rocks from which the springs rise, even the most sparing and finely disseminated iron contents of the rocks are gradually dissolved and carried away by the water. When this water reaches low and marshy land, stagnating under circumstances where it is exposed to a strong evaporation, or where living or decomposing organic bodies exercise a peculiar reaction upon it, the deposit of oxide of iron takes place, and with this the concentration, in a special deposit, of a formerly, perhaps widely disseminated content of iron. A similar event may take place somewhat more rapidly where springs arise from very ferrugi- nous deposlts.or even from certain iron ore deposits; but as a rule, the formation of bog iron ore has no such special cause.

According to Ehrenberg, small living Infusoria also occasionally take part in the formation of the hyd rated peroxide of iron, since they construct their shells of it, as do many species of OaillondIo4. After their death their shells remain, as collections of a fine ochreous iron, which perhaps subsequently hardens and becomes a firm mass."

The theory of the formation of mineral-veins or lodes by electricity is refer- red to by Von Gotta on pp. 58, 59.

"It has frequently occurred that an essential influence on the contents of lodes and particularly on the unequal distribution of ores in them, has been ascribed to the elec

Ibon Ores Of Minnesota. 329

trio currents which may possibly arise from the superposition or contact in any way of somewhat similarly composed rocks. This hypothesis was founded on the fact that during the decomposition of a solution by a voltaic current dissimilar substances are deposited at the positive and negative electrodes. Fox, in fact, by means of artificially -obtained electric currents, not only produced fissures in clay, but also filled these fissures with metallic substances. In consequence of this he is of the opinion that electricity has exerted a great influence in the arrangement of minerals in lodes; he believes in particular that the greater richness of many lodes, on passing from one rock to another, can be explained by supposing that the electro-negative acting rock must have caused a greater deposit.

The fact of electric currents existing In the earth's crust is, however, somewhat un- certain. Prof. Reich, indeed, obtained deviations of the needle when he connected two different points of a lode by means of conducting wires; but he explains this very olearly through the contact of the various ores composing the isolated groups of ore, which are separated by sterile rock acting as a moist conductor. According to this the electric currents were first caused by the distribution of the ores in the lodes; and the reverse cannot as yet be deduced, namely, that this distribution has been caused by inch currents. By connecting points free of ore. Reich was unable to obtain the slightest deviation.'*

Yon Cotta, B. Berg.- u. Huttenm. Zeitung. 1861, pp. 58, 155; 1864, p. 118; 1869, p. 29.

Yon Miller. Berg.- u. Huttenm. Jahrb. d.k.k. Bergakademien, 1864. No. 12. Considers ironstones of Eastern Alps as belonging to the Triassic.

Yon Morlot. Jahrb. d. geolog. Reichsanst. 1850, pp. 104, 118. Iron Ores in the Eastern Alps.

Yon Oppel, Anleitung zur Marksoheidekunst. 1749. Bericht von Berg- bau. 1749.

Von Bath. Leonhard's Jahrb. 1865, p. 98. On Iron Ores of Elba,

Yon 8ohuppe. Jahrb. d. aeoloa. Reichsanst, 1854, p. 369. Iron Ores in the Eastern Alps. Considers them bedded.

Wadaworth. M. E. Proc. Bost. Soc. Nat. Hist., xv, pp. 470-479. 188a *'I hold that they (Iron ores of Lake Superior) are chiefly eruptive, partly Intrusive partly in overflows; also formed in part by decomposition of the jaspilyte and ore in and in part by mechanical and chemical deposition, Op. C, Vol. XVI., p. 103.

Bull. Mus. Comp. Zool. Geol. Ser., 1, p. 75. 1880.

"The general structure of the country would seem to be as follows: The schists, sandstones, etc., having been laid down In the usual way, were then distributed bv the eruption of the Jasper and ore; this formed the knobs of jasper, the banding belong- ing to flu id al structure and not to sedimentation. Besides occurring in bosses, the Jasper was spread out in sheets, and Intruded through the rocks in wedge-shaped masses, sheets and dikes.*' "The iron-ores are regarded as all of sedimentary origin by Foster. Kimball, Dana, Hunt, Wlncholl. Credner, Brooks, Newberry and Wright, but are believed for the most part to be of eruptive origin by Whitney, and Foster and Whitney." P. 27.

Notes on the Books and Ore Deposits in the vicinity of Notre Dame

Bay, New Foundland. A. J, Sci. Hi, vol. xxviii, pp. 94-104. 1884.

On the Origin of the Iron Ores of Marquette District of Lake Su- perior. Proc. Bost. Soc. Nat. Hist, vol. xx, pp. 470-481, 1881; and Eng. Min Jour . vol. xxxii, no. 18, p. 286, 1881. See also Amer. Jour. ser. 8, vol. xxii, pp. 403-407,1881.

. Litholoffioal Studies. Memoirs Mus. Comp., Zool., vol. xi, pt. 1. 1884. 4ta, pp. 208, xxxiii, plate 8.

"In its oxidised forms, and in association with a rook belonging at the other extreme Of the lithologioal scale, siderollte occurs on the southern shore of Lake Superior." p. 64.

"It is probable that but few will claim that the siderolites of meteoric origin were formed by organic agencies. If they were not, it follows that the graphite contained la them could not have been so produced. This has a very direct and obvious bearing on the question whether the graphite In Azoic and other rocks need have been derived from animal or plant remains, and it negatives the supposition*."

make graphite the evidence of life Is the same kind of argument as It is to claim that no oxides of iron and no carbonate of lime could bo found without the Interven- tion of life. One we knew to be oftentimes of volcanic origin, and the other to be fre- quently the product of the decomposition of rocks." {Iak. Cil., p. 67. )

J. Lawrence Smith. Mineralogy and Chemistry. 1873. pp. 1284-310; Am, . Set. 1876 m Si 898-806, 433-442; Walter Flight. Pup. Sci. Rev. 1877. x vC'MO-401.

330 Bulletin No. Vi.

The Theories of Ore Deposits. Proc. Bost. Soc. Nat. Hist. 1884.

Waldenstein, Joseph W. von. Die besonderen Lagerst&tten der nutzbaren Mineralien. Vienna. 1824.

Walter, Bruno. [Ore Deposits of S. Bukowina.] Jahrb. k. k. geol Reich*. Bd. xxvi, Heft. 4, pp. 343-426, 187a

Ores lie generally parallel to the strike of the beds of the formations. True veins are mostly absent, most of the occurrences being analogous to that of a Swedish "fahlband."

Jahrb. d. Jc. k. geol. Reichsanst, 1876*, p. 891 and 415. v. Ootta,

Erzlager-St&tten, II, p. 260.

Ward, J. C. The Geology of the Northern Fart of the English Lake District. Geological Survey Memoir. 8vo. London. 1876.

Wedding, Dr.H. Zeitsch, d. deutsch. geol. GeseU. 1859. p.399. On Iron Ore deposits near Sohmiedeberg.

. Zeitschr. d. d. geol Qesellsch. vol. xi. 1859, p. 899; Zeitschr. f.

d. Berg- u. Hutten. u. Salinenw. im preuss. Stoat, vol. xxiv, 1876, pp. 330, 836, 345, 346. Contains descriptions of the Michigan and other Iron Ore districts.

Weed, Walter H. The formation of Travertine and Siliceous Sinter by the vegetation of hot springs. Ninth Annual Report U. S. GeoL Sur. 1887-88. pp. 619-676; Am. Jour. Sci. iii. xzzvii, May, 1889, pp. 351-859.

Weibye, . LeonharcFs Jahrb. 1847, p. 697. Iron Ores of Arendal,

Norway.

Weiduer, Henrico. Oerro deMeroado. Report to the Mexican Min- ister of the Interior. 1858. 2nd Ed. 187a

Does not think that it is meteoric, nor that Baron Humboldt referred to samples from this mountain when he speaks of enormous masses of malleable iron and nickel found in the neighborhood, (Political Essays on the Kingdom of New Spain, bk. 8, chap. 3, paragraph 2, Spanish ed., 1827). weidner says: I have not had a moments doubt in considering the Cerro de Mercado an eruptive volcano, denying thus the me- teoric origin that has been so freely attributed to it.'* (Trans. Am. Inst. Min. Eng. for 1884. Paper on Cerro de Mercado by John Birkinbine).

Wendt, A. F. Tilly Foster Iron Mine. Trans. Am. Inst. Min. Eng. xiii, pp. 478-484.

Werner, Abraham Gottlob. New Theory of the Formation of Veins with its application to the art of working mines. German Edition, 1791. Translated by Charles Anderson, M. D.t 1809. Edinburgh. 8vo, 23 pp., with an appendix by the translator.

Wethered, E. On the Origin of the Haematite Deposits in the Carbon- iferous Limestone. Coll. Guard, vol. xliv, p. 334, and Rep. Brit. Assoc, for 1882, p. 533.1882.

Whitehurwt, John. Inquiry into the Original State and Formation of the Earth, p. 283. 1778.

Whitney, J. E>. The Lake Superior Copper and Iron District. Proc Bo8t. Soc. Nat. Hist, 1849, iii, 210-212. Stated that Iron Ores are of igneous origin.

Iron Ores of the Azoic. Proc. Am. Assoc. Adv. Sci. 1856, pp. 209-

216. Am. Jour. Sci. ii, vol. xxii, pp. 38-44. 1856.

Maintained that the iron ores of the Azoic system have had a similar method of origin. On p. 210 op. cit. we find him saying with regard to himself and Mr. Foster: "We maintain, therefore:

1. That deposits of the ores of iron exist in various parts of the world* which in ex- tent and magnitude are so extraordinary as to form a class by themselves. The iron regions above mentioned, (Lake Superior, Scandinavia, Missouri and northern New York), offer the most striking examples of the deposits now referred to.

2. That the ores thus occurring have the same general character, both mineraloglc- ally and in their mode of occurrence, or their relations of position to the adjacent rocks.

Iron Ores Of Minnesota. 331

3. That these deposits all belong to one geological position, and are characteristic of It."

That he did not consider all iron ores as of eruptive origin is shown by the following:

Moat of the veins which are wrought in mines throughout the world are but a few feet in width, often not more than a few inches. This Is true of the ores occurring in veins. In sedimentary metalliferous deposits, such as those of the ores of iron in the Carboniferous, the horizontal extent is often very considerable; but the vertical range is so limited that the most extensive basins may oc in time exhausted, when worked on so extensive a scale as is the case in some of the celebrated iron districts of Great Brit- ain. The mode of occurrence of these ores In the regions above mentioned is so peculiar, that from this point of view alone, it is apparent that these deposits should be classed together as distinct from those in the later geological formation. In all the characteristics of true veins, the great masses of ore now under consideration are wholly wanting. Some of the least Important of them approach much nearer to segregated veins, and might with propriety be classed with them, were they not de- veloped on so large a scale as to render it difficult to conceive of segregut ion as a suf- ficient cause for their production.

In the case of the most prominent masses of ore of these regions, there is but one hypothesis which will explain their vast extent and peculiar character. They are supply parts of the rocky crust of the earth, and, like other Igneous rocks, have been poured forth from the interior in a molten or plastic state. No other origin can be assigned to the dome-shaped and conical masses of Lake Superior and Missouri, or to the elongated ridges of the first-named region. The eruptive origin of the. great Lake Superior ore-masses seems also well sustained by the phenomena which they exhibit. They alternate with trappean ridges whose eruptive origin cannot be doubted, and which, themselves, contain so much magnetic oxide disseminated through their mass, as one of their essential ingredients, that they might almost be called ores. These eruptive masses include the largest and purest deposits of ore which are known in the Lake Superior or the Missouri iron regions: but there are other localities in both these districts where the mode of occurrence of the ore Is somewhat different, and where the evidences of a direct aqueous origin are less marked. This class compre- hends those lenticular masses of ore which are usually Included within gneissoldal rooks, and whose dip and strike coincide with that of the gneiss Itself, but whose di- mensions are limited. Such is the character of most of the Swedish deposit**, and of many of those of northern New York. Such beds of ore as these may in some rases bo the result of segregating action, but the facts seem rather to indicate that they are made up of the ruins of pre-existing Igneous musses which have been broken and worn down during the turbulent action which we may suppose to have been preeminently manifested during the azoic epoch, and then swept away by currents, and deposited in the depressions of the sedimentary strata then in process of formation."

"There is still another form of deposit which Is not infrequently met with in the Lake Superior region, and which may be seen in a grand scale on the Pilot Knob of Missouri. This consists of a series of quartzose beds of great thickness, and passing gradually into specular iron, which frequently forms bands of nearly pure ore. alter- nating with bands of quartz more or less mixed with the same substance Some of the deposits In the Lake Superior region are of this class, and they are very extensive, and capable of furnishing a vast amount of ore, although most of it Is so mixed with - ekras matter as to require separating by washing before use. Heavy beds of nearly

Sire ore occur at Pilot Knob, lnterstratlfied with beds of poorer quality. Deposits of is character are usually very distinctly bedded, and the ore shows a greater ten- dency to cleave Into thin lamina) parallel with the l>edding. In proportion to its free- dom from sillcious matter. These deposits seem to have been of sedimentary orlgin- having been originally strata of Hlllelous sand, which has since l>cen metamorphosed. The iron ore may have been Introduced either by sublimation of metalliferous vapors from below during the deposition of the sillcious particles, or by a precipitation from a ferriferous solution. In which the stratified rocks were in processor formation."

Wbitney, J. D. Mining Magazine, N. Y. 1856., vii, pp. 67-73. Con- sidered iron ores of Lake Superior and other regions as of eruptive origin.

. Iowa Geological Report. 1858.

>y, Col. Cha*. Proc. A. A. A. S. 1867. p. 98.

"About five hundred miles north of the Iron mountains of Missouri, on the waters of Lake Superior, occur the iron mountains of Michigan and Wisconsin. Those In the latter state occupy a belt about thirty miles- in length, extending south-westerly from the boundary' on Montreal river, at a distance often to twenty miles from the lake. This ore 1b wholly magnetic and occurs as a stratum, in a belt of stratified azoic quartz, dipping, northwesterly, at a high angle beneath the copper-bearing trap."

"Thus the notable deposits of magnetic and specular iron ore are found associated with the quartz rocks, hornblende rocks, porphyry, micaceous schists and doloinltlc marbles, composing the most ancient metamorphl'c Series. If themctamorphlsmof the Laurenttan and Huron Ian formations shall be regarded as an established geological fact, the separation of the oxides of iron from these rocks Into veins, beds and masses can be easily accounted for. All sedimentary strata contain ihe oxides of iron: and any agent powerful enough to change the crystalline form of rock would bring a bout a concentration of their minerals. Metals, their oxides and salts, possess an inherent qpalltT of segregation. Whenever the condition of the enclosing slrata is such as to allow of motion among particles having the affinity of segregation, they must obey this affinity and become more concentrated." (i.e. p. lhl.j

Still again we find. 1. c. p.

"But more recent investigations show that hematite Is not necessarily of sedimen- tary origin. Hydrates are common in rocks which are still regarded as Igneous.

332 Bulletin No. Vi.

Throughout the masses of specular ore In Marquette county, Michigan, are large bunches of hematite, so extensive as to form a material part of the ore now mined. Hematites are too extensive and too far below the surface to admit a general theory of recent and more local changes.

Depth has disclosed no modifications in the ores of the Green mountains; and sine* these beds were subject, on account of their softness, to great destruction by the drift forces, the bottom of the present mines, in some places more than one-hundred feet down in ore, must be regarded as much more than that distance below the original sur- face. The causes which concentrated the ore along this line of several hundred miles, everywhere in contact with metamorphio- limestone, must have been universal and not local. Iron in some form exists in all rooks. The limestone beds of the Clin- ton and Hudson river groups are charged with it, especially near their junction, where the oolitic or dye- stone ore is generally found. If these strata should undergo a molec- ular change, whatever the agent might be, it must act, at the same time, as a concen- trator of their mineral contents. In this action limestone seems to be an almost nec- essary medium or facilitator. The belief in a wide spread, almost an universal, met- amorphism of the rooks is rapidly gaining ground. In this mysterious but acknow- ledged force, which produces a new crystalline arrangement, have we not all the re- quired agencies to produce masses of any mineral which existed in the strata prior to the change? Is not something more necessary to account for the results— some cause more universal than local chemical action?"

Whittlesey, Charles. On the Origin of the Azoic Rooks of Michigan and Wisconsin. Proc. Am. Assoc. Adv. 8cu, 1859, xiii, 301-308.

The Penokie Mineral Range, Wisconsin. Proc. Bost. Soc. Nat.

Hist., 1863, ix, 235-244.

. Physical Geology of Lake Superior. Proc. Am. Assoc Adv. Sci

1875, xxiv, 60-72.

. On the Origin of Mineral Yeins. Proc. Am. Assoc. Adv. Sci.,

1876, xxv, 213-216.

"My objeot will be to show that electricity in some of its manifestations, may be r garded as the principal agent, or force, which accomplishes the filling of veins. I shall use this term in its general sense, to cover galvanism, electro-magnetism and all other modes of electrical action. The term fissure, or fissure-vein will also be used generically; embracing balls, vugs, stock- werks, floors and bunches, as well as true veins."

. Iron Ores of the Great Seam Goal Region. Cleveland, 1877.

Wichnianu, A. GfeoLSur. Wis., vol. iii. 1880.

Will cock, J. On the History, Progress and Description of the Bowling Ironworks. Rep. Brit. Assoc, for 1873, sections, pp. 219*222.

"The geology around Bowling and the character of the coal-seams and Ironstone are described.

Williams, J. J. The Mineral Resouroes of Flintshire and Denbighshire, ana. N. Engl. Inst. h.ng., vol. xxv., pp. 81-100. 1876.

Williams, W. M, Iron and Steel Manufacture. Lecture 1, Journ. Soc. Arts, vol. xxiv., No. 1234, p. 827. 1876.

Winchell, Alexander. Rep. Oeol. Sur. Mich, 1870. pp. 26, 27.

"The rich masses of magnetic and hematitlc ores of iron are found not to be those erupted outbursts which the older geologists were inclined to regard them. They are simply constituents of the system of sedimentary deposits which make Up the Huron- ian system of Michigan."

. Sixteenth Annual Report Geological and Natural History Sur- vey of Minnesota. 1887. p. 367.

"As to the eruptive origin of the hematites and associated jaspilytes, the evidences of it are so slender that the doctrine would only excite my wonder, if it were not held by a few geologists of good reputation. The difficulties of that view are many, but I must embrace another occasion to set them forth.'*

. Recent Observations on some Canadian Rooks. Am. Geol., vol. vi:

Nos. 5, 6. 1890. Describes hematite occurring in true veins with walls of quartzyte or in connection with dioryte dykes.

Winchell, N. H. Geological and Natural History Survey of Minnesota, Fifteenth Annual Report. 1886. Origin of the iron ore and jaspilyte of the Keewatin is treated of in pages 223-247. The eruptive theory is discussed but not adopted. Suggests that the hematites may have been formed by a substi- tution of iron oxide for lime carbonate.

Iron Ores Of Minnesota. 333

Winchell, 1*. II. and H. V. On a possible chemical origin of the iron ores of the Keewatin in Minnesota. Am. GeoL vol. iv. No. 5. 1889., pp. 291- 800; voL iv, No. 6, pp. 88 2- 385; A. A. A. 8. 1889. ;

Winchell, H. V. The Diabasic Schists containing the jaspilyte beds of northeastern Minnesota. Am. Qeol, vol. iii, No. 1. 1889. pp. 19-22.

Wilson 9 l>aniel. The Southern Shores of Lake Superior. Canad. Jour., 1856, (2,) i, 344-356.

Wohler, F. [Greenland Native Iron.] N. Jahrb, pp. 832-834. 1879.

Wolff, G. Zeitschr. d. d. geol. Geseltech. 1877. Bd. 29, p. 149.

Wood, W. M. Mineral Deposits in Southern States of America. Jour. 8oe. Arts, vol. xxxii, No. 1646, pp. 734, 785. 1884.

Woodward, H. B. Geology of East Somerset and the Bristol Coal- fields. Pp. z, 271, 9 plates. Geological Survey Memoir. 8vo. London. 1876.

Wright, Chas. E. 1st Annual Report Commissioner Mineral Statistics of Michigan. 1879. p. 15.

"In these mines It appears that the finely divided silica has been more or less dis- olved out by alkaline thermal water, leav* He regards the ores of sedimentary origin.

solved out by alkaline thermal water, leaving the iron oxide and other bases behind.

1881, pp. 153-230.

Annual Report of Commissioner of Mineral Statistics of Michigan,

. Annual Report of Commissioner of Mineral Statistics of Michigan,

1880, pp. 162-250.

Wright, O. B. Alder. Ercyclopcedia Britannica, Ninth Edition, vol nil, pp. 286, 287. In the article on "Iron":

"Haeraatitio ores are usually found in the oldergeological formations, -especially the Horonlan, Cambrian, Silurian, Devonian and Carboniferous rocks; in many cases they are of distinctly sedimentary character, (. they have obviously been deposited by aqueous agency. Some deposits have probably been originally thrown down either as ferric oxide detritus from the abrasion of rocks, etc., containing ferruginous matter, or as hydrated oxide from the oxidation of water containing ferrous oar Inm- ate in solution, the ochreous deposits thus formed having been rendered more or less completely anhydrous and Indurated by the long-continued effect of pressure and the conduction of the Internal heat of the earth to them. The Cumberland hamatlte largely occurs in pockets in Carboniferous limestone, and lias doubtless been produced by the latter kind of agency, the Cavities of the limestone rock becoming gradually filled up by the deposition of iron oxide. Ked sandstones, on the other hand, represent deposits of ferric oxide thrown down simultaneously with much sand; whilst the earthy varieties of haematite have probably been less indurated by heat and pressure and were doubtless formed by deposition from water containing clavey matters in suspension to a greater or less extent . The Alabama deposits exhibit distinct strati- fication, forming a bed l>ctwceii the Coal Measures and the Devonian Limestone up- wards of 100 feet in thickness, and several square miles in extent. In Cornwall. North Wales, and especially In the Lake Superior and Missouri districts, the hsematltlc de- posit* form large veins and lodes. The specular ores of Elba, Sweden. Missouri and elsewhere usually occur as massive deposits; portions of the latter occasionally show the passage of spat hose ore into specular ore (Snclus), suggesting the effect of heat accompanied by oxidizing action. Occasionally brown hiviiiatite is found passing into red* Indicating gradual dehydration more complete in one portion of the deposit than

In another Many deposits (of brown hematite) have been apparently

formed by the alteration of argillaceous ferrous carbonate; others from superficial sandy beds, produced by the deposition of ochreous matter from solution either by purely chemical action, such as the oxidation of dissolved ferrous carbonate, or by

the action of organized beings, especially Diatomaceie Usually brown

hJematites are distinctly of sedimentary character, forming beds; but they often occur also as veins, especially In the older format Ions, doubtless deposited (often along with other minerals e. g. copper ores) from water flowing through the cracks and ore vices of the rooks."

Metals and their Chief Industrial Applications.

Wurttenberger, . Xeues Jahrb. f. Mineral. 1807, p. 685.

Wursburger, P. On the Geology of the North Lancashire and Cumber- land Iron-ore Districts. Journ. Iron Steel Inst., No. 2, 1874, pp. 287-296.

The Hematite deposits occur as veins in the Lower Silurian, but are both larger and purer in the Mountain Limestone— as "flat deposits which follow or leas the dip," as veins, and filling irregular hollows.

"Wyley, Andrew. The Iron Industries of Upper Austria. Proc. Dudley GtoL Sne., vol. 8, No. 8, pp. 45-47. 1877. 9

334 Bulletin No. Vi.

Zaytzev, A. [Preliminary account of geological researches in the Urals, made in 1885.] Bull Com. GSoL, No. 2, pp. 57-85.

. [Geological description of the region of the Revdinsk and Werkhne*-

Issete forges and their environs.] Mim. Com. Qiol.y T. iv., No. 1, pp. 1-140.

[Preliminary account of geological investigations in the Urals in

1887.] Bull Com. QioL, No. 7, pp. 263-288. 1888.

Zemiatschensky, P. [The iron ores of Gentral Bussia.] Trav. 8oc. Natur. St. Petersburg. Vol. xx, pp. 1-306, plate. 1889. "Part three considers the age and the or Iff in of the ores. The author is driven to the

ige ana the origi following conclusions: All the minerals of the region studied are simply spherosider- - -lQf

he careous rocks. Some of the limestones are aolomitlo. Hydrocfiemical processes

ig conclusions: Ail tne minerals of tne region stuaiea are simply ite and limonlte, the latter being always (?) of secondary origin, arising from the decomposition of the sp hero-side rite. All (?) the minerals are directly allied with the various limestones, and have been produced by the action of irony solutions on cal-

which have given rise to these iron minerals are manifest through a whole series of geological periods, and have been of various durations. There are some which are still active at present."

Zepharovich, v. Neues Jahrb.f. Miner. 1865, p. 60; 1867, p. 715,

and 1870, p. 355.

Zerrenner, . Zeitschr. d. d. geol. Qesellsch. Bd. 1, 1849, p. 475.

Zimmerm%nn, Die Wiederansrichtnng verworfener Grange,

Lager und Plotze. Darmstadt und Leipzig, 182H.

. Das Harzgebirge, 1834, p. 98.

Zimmerman, C. F. Ober-Sachsische Bergakademie. Dresden. 1746.

Zimmermanii, . In KarsterCs Arch., 1837, vol. x, p. 26, Iron Ore

deposits of the Hartz are described.

Zioken, . Der ostliohe Harz, vol. i, p. 135. 1825.

Zirkel, . Petrographie. I. 1866\ p. 341. 1

Zouloukidze, G. [Geological researches in the region of the Alguetka and Ehrama valleys.] Mat. OioL Caucase. Ser. II, livr. 1, pp. 1-70. 1895.

Part Vi.

LIST OF COMPANIES INCORPORATED UN- DER THE LAWS OF MINNESOTA FOR THE PURPOSE OF MINING AND

Quarrying.

mis name of the oompany is stated first, then the place of its principal office, amount or capital stock, number of shares, date of incorporation, and names of Incorporators In order. This list is complete up to Dec. 1, 1890. J

Abacus Iron Mining Company; St. Paul; $1,000,000; 10,000 shares; March 31, 1887. A. D. MoLeod, G. G. Olcutt, W. R King, W. N. Viguers.

A. E. Maher Mining, Smelting and Milling Company ; St. Paul; 120,000; 4U0 shares; Nov. 19, 1888. A. E. Maher, P. H. Raaohe, W. H. Hopson.

Alaska Treadwell Gold Mining Company; St Paid: $5,000,000; 300,000 shares; Nov. 21, 1889. J. A. Humphreys, S. E. Day, W. H. Williams.

Algoma Gold and Silver Mining Company; Minneapolis: $2,000,- 000: 200,000 shares: May 5, 1888. G. N. Murdook, A. D. Dunn, F. J. Bletcher, A. J. Glmsted, H. J. G. Oroswell, G. H. Browne, B.B. Enapp, £. E. McDonald.

Anchor Iron and Smelting Company; Minneapolis; $1,500,000; 60,- 000 shares; Aug. 29. 1887. J. F. Force, B. Gloutier, L. Matthews, F. Murdook, R.E. Trafton.

Ancient Diggings Company; Cook county, Minn., and Detroit, Mich.; $1,000,000; 40,000 shares; May 23, 1885. W. P. Spalding, T. S. Spragne, a J. Hunt, W. F. Eberte, H. S. Sprague.

Arizona Northern Mining Company; Minneapolis; $75,000; May 22, 1880. J. Barry, A. Kelly, P. H. Kelly, W. W. MoNair, J. K. Sidle, G. H. Christian, G. H. Keith, W. D. Hall, T. S. King, R. J. Baldwin.

Arrow River Mining and Manufacturing Comf*any; Minneap- olis: $2,500,000; 250,000 shares; Aug. 20, 1881 W. W. Braden, J. H. Baker, J. MoGuire, S. Leavitt, F. P.Lane.

Ashland Iron and Steel Company; Minneapolis: $250,000; 2,500 hares: Oct. 18, 1886. J. E. York, A. H. Linton, R B. Langdon, 0. L. Lang- don, BL. 0. Henry, W. W. Eastman, J. H. Oiarke, W. J. Van Dyke.

Avalanche Mining Company; Yemdale; $500,000; 50,000 shares: April 5, 1886. E. S. Case, E. K. Nichols, BL A. Thompson. A. F. Stewart, T. Tinkel- paugh.

Bald Mountain Mining Company; Minneapolis; $2,500,000; 100,000 shares; April 12, 1884. R S. Innes, R. D. Russell, G. B. Kirkbride, S. P. Snider.

Bearer Bay Mining Company; Daluth; $1,000,000; 200,000 shares; Maroh 25, 1885. E. B. Jefferson, E. 0. Howard, B. G. Segog, J. A. Stock- bridge, 0. E. Wheeler.

Bed Bock Iron Mining Company; Minneapolis; $600,000; 60,000 hares; Aug. 10, 1687. L. N. Sharps, N. S. Lockwood, C. E. Case, E. O. Cos- man, B. B. Peaslee, A. H. Noyes, B. F. Teall.

336 Bulletin No. Vi.

Belle Platne Salt Company; Belle Plaine; $15,000; 800 shares; Aug. 16, 1872. a A. Hooper, S. A. Packer, R H. Rose, A. G. Ohatfield, M. M. Cfcreon, a T. Metzener, H. B. Gates, W. T. Woods, I. P. Black.

Ben Harrison Gold and Silver Mining Company, of Granite Falls, Minnesota: Granite Falls; $125,000; 5,000 shares; Dec. 5, 1888. S F. Scott W. N. Allen, O. S. Richards, J. M. Thompson, M. Campbell, G. Powers.

Biwabik Mountain Iron Company; Dnluth; $2,000,000; 20,000. shares; Oct 9, 189a L. Merritt, E. H. Hall, J. J. Wheeler.

Bishop Iron Company; Chicago, Bis.; $1,000,000; 40,000 shares; March 28, 1889. J. C. Sterling, R Forsyth, 0. W. Hillard.

Black Hawk Land and Mining Company; Glencoe; $100,000; 20,- 000 shares; May 17, 1890. H. B. Strait, 0. T. Buchanan, J. A. Coller, J. C. Buchanan, G. K. Gilbert, R Buchanan, M. T. Gitchell, L. W. Gilbert, C. H. Silvers.

Black Hills Tin Mining: Company; St Paul; $1,000,000: 200.000 shares: April 18, 1888. R J. Truax. J. MoNamara. S. J. Truax, J. A. South all, J. A. Smith, C. Madden, J. L. Fox, J. Mory. N. L. Bailey, et al.

Blair Manganese Mining: Company; Minneapolis; $125,000; July 24, 1888. T. E. Penney, F. E. H. Bruen, J. B. Shoenfelt. G. B. Shoenfelt

Boston Iron Mining: Company; Minneapolis; $1,000,000; 40,000 shares: Jan. 29, 1887. E. J. Shaw, G. W. Payne, E. A. Sumner.

Brazil Iron Mining Company; St. Paul: $1,000,000; 40,000 shares; June, 25, 1887. M. D. Miller, N. P. Frost, B. F. Wright, J. D. Bisbee.

Bristol Silver Mining: Company; Minneapolis; $50,000; Dec. 19, 1879. G. H. Keith, R J. Baldwin, F. A. Lewis, J. B. Oiooker, G. B. Mead, W. S. King, H. M. Goodhue, M. W. Lewis.

Brookfield Mining: Company; Duluth; $500,000; 50,000 shares; Feb, 9 1887. W. O. Hughart, Jr., J. D Howard, J. D. Ensign, D. G. Cash, A. J. Whiteman.

Cabinet Consolidated Mining: Company; Minneapolis; $1,500,000; 150,000 shares; Aug. 30, 1883. C. C. Hughes, J. C. Howard, J. A. Laach, D. B. Burdette, E. O. Stewart, J. F. Reed, W. 0. Tonkin,

Cambria Mining:, Milling: and Smelting: Company; St. Paul; $1,000,000; 100,000 shares; Aug. 21, 1884. J. Edwards, N. M. Singleton, F. B. Howell, J. K. Stone, R W. Cavenaugh.

Canton Iron Company; Chicago, 111.; $50,000; 2,000 shares; April 13 1889. R. Spencer, A. C. Ely, J. H. Chandler.

Carbonette Mining: and Milling: Company; Black Hawk, CoL; $1,000,000; 200,000 shares; Sept. 14, 1887. 0. Al MoLain, A, B. Roberts, J. Owens.

Carlotta Gold Mining: Company; St Paul; $1,000,000; 100,000 shares; March 20, 1885. J. S. Prince, G. Mitch, R W. Johnson, A. Allen, E. H. Strong, N. H. Hemiup.

Carleton Land. Mineral and Mining Company; Duluth; $100,000; 2,000 shares; Aug. 29, 1890. H. J. Jewett, H. B. Payne, H. M. Rice, J. Wade S. T. Everett

Central Iron Mining: Company; Minneapolis; $1,000,000; 100.000 shares; May 20, 1887. J. 0. Joslyn, W. P. Buell, D. A. Pool, G. C. Card, C. S. Sedgwick, O. W. Betts, J. Lucas, C. P. Beard.

ChRmpion Iron Company; Duluth; $1,000,000; 40,000 shares; March 2,1889. J. L Gilbert, W. McRae, C. F. Howe.

C andler Iron Company; Duluth; $1,000,000; 40,000 shares; May 2, 1887* J. H. Chandler, J. H. James. H. J. Pickands, J. C. Morse, A. 0. Ely.

Ikon Obes Of Minnesota. 337

Chengwatona Mining Company; St. Paul; 8100,000; 4,000 shares; Nov. 11, 1880. J. P. Ilsley, J. B. Smith, J. P. Ilsley, J. J. Porter, J. Smith, Jr.

Chippewa Tron Company* Chicago, Ills.; $1,000,000; 40,000 shares; April 13, 1889. R. Spencer, A. 0. Ely, J. H. Chandler.

Clyde Iron Company; Duluth; 8100,000; 1,000 shares; Oct. 24, 1889.

C. P. Craig, James Cash, J. W. Anderson, D. G. Cash, J. G. Williams.

Coleman Mining Company; Winona; $2,500,000; 100,000 shares; Sept. 20, 1881. W. P. Phelps, H. D. O'Neill, C. H. Berry, C. L. Bonner, P. Hueff- ner, G. Doud, R. F. Doud.

Colville Mining Company; St. Paul; $1,500,000; 300,000 shares; Nov. 12, 1887. W. D. Stearns, H. E. Goodrich, W. E. Monroe.

Consolidated Clancy Creek Mining Company; Minneapolis; $2,500,000; 100,000 shares; April 12, 1884. S. H. Baker, W. H. Eastman, S. P. Snider.

Consolidated Vermilion Tron and Land Compauv; Duluth; $1,000,000; 100,000 shares; May 12. 1887. R. S. Munger, J. T. Hale, D. G. Cash, J. M. Smith, F. A. Day, G. W. Kimberly, H. W. Coffin, A. P. House, 0. F. Diokerman, S. W. Matteson.

Crescent Iron Mining Company; Duluth; $200,000; $40,000 shares; Feb. 13, 1890. J. McKinley, 0. E. Shannon, J. H. James, J. Shephard, J. G. Brown.

Crested Butte Mining and Smelting Company; St. Paul; $259,- 000; 50,000 shares; Deo. 18, 1883. B. Beaupre, D. Byan, F. Keogh, J. C. Meloy, LE. Finoh.

Crown Point Mining Company; Minneapolis; $2,500,000; 100,000 hares; April 12, 1884. K. S. Innes, A. J. Trimble, S. P. Snider.

Crown Point Mining Company ; Duluth; $600,000: 60,000 shares; May 31, 1890. A. D. Oummings, H. R. Tiakbam, E. Tinkham, Hdlyer, G. A. Elder, J. Billings, C. E. Shannon, J. Bond, Jr.

Dakota Qold Mining Company; Minneapolis; $300,000; 10,000 shares; Jane 16, 1880. J. P. Wilson, S. A. Reed, M. A. Larson, M. Aspland, L. L. Baxter.

Dakota Iron and Steel Company; Minneapolis; $750,000; 15,000 hares; May 4, 1886. W. Baker, E. R. Kent, R. B. Mum ford.

Dakota Mining Company; Minneapolis; $100,OOC; 10,000 shares; April 14, I860. J. Anderson, S. A. Reed, M. A. Larson, M. Aspland, R. L. Baxter.

Delaware Iron Company; Chicago, 111.; $50,000, 2,000 shares; April 18, 1889. R Spenoer, A. 0. Ely, J. H. Chandler.

Derwood Consolidated Mining and Milling Company; St. Paul; ttVXXMXX); t00.000 shares; Dea 14, 1888. J. A. McKinley, J. A. Brent, W. B Bparkmtn, J. W. Erwin, F. F. Ellis, T. H. Monahao.

Detective Mining Comnany; Minneapolis; $2,500/00; 100,000 shares April 19, 1888. P. J. Drew, J. H. Wheeler, J. A. Northrop, O. S. Northrop.

Da' nth and Nva Scotia Mining Company; Duluth; $1,000,000: 100,000 shares; Dea 8, 1886. H. Burg, M. Haug, C. Poirier, H. F. Miller, M. Fink.

Frown Stone Company; Dnluth; $30,000, 600 shares; March U, 1887. J. H. Crowley, A. MoDougall, F. B. Lazier.

Dulnth Gold and silver Smelting and Refining Company, Duluth; $100,000, 1.000 shares; Ang. 18, 1887. H. H. Hawkins, J. H. Triggs, F. & Kennedy, J. B. Sutphin, L. W. Young.

Iron Company; Duluth; $100,000, 4,000 shares; Nov. 19, 1879.

D. M. Bafain, C. H. Graves, G. Spencer, J. Ilsley, 0. F. Graft.

338 Bulletin No. Vi.

Dnluth Iron Mining and Development Company; Duluth, $1,000,0P0, 100,000 shares, Nov. 19, 1886. a Chapman, G. 0. Greenwood, J. BL James, J. Sheridan.

Duluth Mineral La"d Company; Duluth; $35,000, 1,400 shares; Deo. 27, 1884 W. C. Sargent, H. C. Kendall, E. V. Muody, W. Bunnell, EL B. Moore, J. Bice, A. Fraser.

Duluth Mining and Smelting Companv; Dnluth: $1,000,000, 10,000 ehares; Jan. 11, 1887. R S. Munger, J. D. Ensign, A. N. Seip, J. R Myers, O. N. Simonds.

Dulu'h Mining Stock Exchange; Duluth; $500,000, 10,000 shares; March 28, 1887. F. W. Eaton, R. H. Fagan, N. B. Thayer, H. EL Bell, J. Fraser, J. B. Sutphin, J. W. Anderson.

Duluth Natural Gas Oil and Mineral Company: Dnluth; 8100,000; 1,000 shares; Aug. 10, 1887. W. A. Foote, J. D. Ray, J. B. Carey, li. Menden- hall, J. H. Triggs, N. J. Miller, S. E. Cheeseman.

Duluth Silver and Copper Mining Company; Dulutb: $200,000; 100,000 shares; Dec. 10, 1883. H. A. Douglas, B. Brown, C. Markell, M. Daniels, H. W. Pearson, M. Fink, H. H. Bell.

Eagle Mining Company; St. Paul; $1,000,000; 100,000 shares; June 16, 1882. F. Beebe. J. A. Conlee, J. M. Gilman, C. Eaton.

East Hoppenyan Tron Mining Company; Minneapolis; $1,000,000; 40,000 shares; Oct. 4, 1887. J. Paulson, E. Farnsworth, Jr., W. P. Andrus, O. J. Nevitt, W. A. Hemphill, M. FitzSimmone, S. H. Soule.

Eden Prairie Mining Company; Minneapolis; $1,000,000; 10,000 shares; Jan. 14, 1889. R J. Anderson, E. U. Loose, D. A. Fisk.

Ellsworth Consolidated Mining Company; St. Paul; $1,000,000; 2C0,000 fchares; Nov. 1881. A. DeGraff, E. S. Goodrich, R Knapp.

Enterprise Iron and Lead Company; Duluth; $50,000; 2,000 shares; Dec. 21, 1889. J. Frank, E. Hartmann, L. Moss, L. Minzesheimer, D. Good- man.

Equator Mining Company; Minneapolis; $10,000,000; 200,000 shares; Nov. 11, 1887. T. B. Stone, E. B. Burdick, J. E. Merritt, J. W. Griffin.

Fayal Iron Company; ChicPgo, Bis.; $50,000; 2,000 shares; April 13, 1889. R Spencer, A. C. Ely, J. H. Chandler.

Flag River Brown Stone Company; Duluth; $30,000; 600 shares; Jan. 29, 1889. J. F. Fredin, A. Broman, F. H. Quinby, C. W. Wilson, G. J. Miller, S. J. Miller.

Florel'a Mining Company : Minneapolis; $10,000; 200 shares; Dec. 29 1884. C. P. Cole, A. Y. Merrill, A. W. Stow.

Florence Mining and w melting Companv; St. Paul; $100,000; 4.000 shares; Dec, 24, 1878. C. W. Carpenter, D. A. Montfort, 0. Eaton, C. S. Mine, W. Dawson, R A. Smith, N. W. Kittson, J. J. Hill.

Freeborn Consolidated Coal Mining Com pan v; Alden; $40,000; 1,600 shares; Feb. 14, 1882. E. G. Clark, E. G. Perkins, W. W. Cargill.

French River Mining Company; Duluth; $100,000; 2,000 shares; Aug. 16, 1863. R T. Paine, H. B. Paine, R B. Carlton, E. Goodrich, G. L. Becker.

Galena Silver Mining and Milling Company; St. Paul; $1,000,000; 200,0( 0 shares; March 22, 1887. A. M. Levy, 0. E. Fowler, H. H. Hamilton, C. M. McLain, J. Q. Haas.

Iron Obes Of Minnesota. 339

Germania Iron Company; Duluth; $50,000; 500 shares; June 4, 1889.

E. Hartmann, W. W. Billson, E. 0. Little.

Gitcheg"mee Gold and Silver Mining: Company; Minneapolis: $2,000,000; 200,000 shares; May 7, 1888. A. F. Olmsted, H. J. G. Croswell, O. N. Murdock, T. J. Bletcher, J. Kaufman.

Gogebic Bessemer Ore Company; Minneapolis; $5,000,000; 200,000 shares; Feb. 14, 1890. W. Pond, J. N. Cross, F. H. Carle ton, N . M. Cross.

Gogebic Development Company; Minneapolis; $5,000,000: 200,000 shares; April 26, 1887. S. P. Snider, J. W. Pence, A. J. Trimble, S. E. Neiler, T. J. Buxton, M. I*. Hallo well Jr., A. H. Hall.

Gogebic Pr'ze Iron Mining Company; St. Paul; $800,000; 80,000 shares; June 9, 1887. H. Laycock. A. B. Roberts, H. W. Knapp, O. A. Turner, W. B. Stephens.

Gold Hill Mining Company; Minneapolis; $5,000,000; 200,000 shares: May 28, 1886. D. B. Burdette, J. B. Collins, J. K. Wright, G. F. Jackson, N. C. Tomkins.

Gold Hunter Mining and Smelting Company; St. Paul; $2,000,- 000; 200,000 shares; Feb. 2, 1887. D. Ryan, P. T. Kavanaugh, K. B. Galusha, P. M. Hennessy, B. A. Cox.

Gold King Mining and Milling Company; Denver, Col., and St. Paul; $750,000; 150,000 shares; Dec. 30, 1885. C. A. Heffelfinger. A. M. Levy,

F. P. Lane, F. Cramer, G. Canfield.

Gold River Mining Company; Duluth; $500,000; 50,000 shares; June 25, 1887. J. D. Ensign, O. P. Stearns, H. A. Smith, J. B. Howard.

Gopher Gold and Silver Mining Company; Minneapolis; $100,000; 100,000 shares; July 28, 1890. J. W. Griffin, L. Swift, Jr., J. R. Jones, H. A. Turner, R Blaisdell, A. F. Olmsted.

Grand Mara's and Vermilion Iron and Land Company; St Paul; $2,000,010; 80,000 shares; Dec, 1887. G. M. Smith, C. T. Dunbar, A. Delaney, J. E. Mo Williams, J. F. Van Sickle, R W. Cavenaugh, T. W. Ken- nedy, E. 0. Dunn, et al.

Granite Falls S*one Quarry Company: Granite Falls; $10,000; 1,000 shares; Sept. 5, 1887. J. G. Dodsworth, W. W. Penney, K. E. Neste, C. J. Goodenow; D. A. McLarty.

Great Western Mining Company, of Pennsylvania; $5,000,000; 500,- 000 shares; Jan. 26, 1870. T. S. Emery, S. Knapp, G. St urges, G. B. Fitts, W. fallen.

Hall Iron Mining Gompany; Duluth; $500,000; 20,000 shares; Jan. 10, 1888. F. H. Frisbee, J. A. Hall, G. 0. Howe, P. M. Graff, F. L. Murray.

Ham's Fork Coal Mining Company; $2,500,000; 100,000 shares; Deo. 8. 1884. O. J. Johnson, H. Brintuell, J. W. Cochran, H. N. Anderson, H. C. Peterson, P. P. Swenson, H. Church, A. A. Bailey, I. C. Winslow.

Hartmann- Mallet Iron and Land Company; Duluth; $1,500,000; Dec 1, 188a E. Hartmann, R. D Mallet, J. T. Hale.

Hawkeye Mining Company; St. Paul; $2,500,000; 100,000 shares; May 24, 1880. J. A. Hughes, Jr., R. P. Hughes, S. Newell, R. Merriam, H. B. Willis, G. B. Young.

Hekla Iron Mining Company; St. Paul; $1,000,000; 40,000 shares; March 11, 1887. F. M. Morris, H. B. Watson, H. B. Nor vi lie, H. 0. Masters, H. J. Overholzer, O. J. Nevitt, C. B. Walker, C. C. Greeley, et al

Hematite Iron Company; Duluth; $1,000,000; 40,000 shares; July 27* 1887. J. B. Sutphin, J. C. Clark, H. C. Kendall, F. W. Eaton, H. A. Blume, O- W. Traphagen, F. N. Parcher.

Hennepin Mining Company; Minneapolis; $2,500,000; 250,000 shares; March 8, 1887. E. J. Davenport, G. D. Emery, J. V. Nye.

340 Bulletin No. Vi.

Hidden Treasure Gold Mining? Company; St. Paul: $5,000,000; 600,000 shares; Dec. 19, 1887. D. O. Price, L. D. Hause, J. C. Cabanne, W. Wilkin, 0. Phillips, R F. Hersey, E. L. Hersey, W. W. Price.

Higins Wildcat Company; Duluth; $2,000,000; 2,000 shares; March 3, 1890. W. H. Butler, O. T. Higgins, F. R. Webber, C. D'Autremont, G. Gil- bert, W. H. Acker, F. W. Higgins, H. O. Morgan, et al. .

Home Gold and Silver Mining Company, of Wabasha; $500,000; 10,000 shares March 19, 1865. W. T. Dugan, J. F. Rose, D. H. Eldridge, O. J. Noble. S. Wells, E. S. Wills, J. H. Mullen.

Home Iron Mining Company; Dnluth; $1,000,000; 40,000 shares; Dec. 13, 1887. R N. Marble, J. Flynn, E. Hartmann, R D. Mallet, H. R Haivey.

Home Mining: Company, Duluth; $1,500,000; 150,000 shares; April 10, 1885. J. D. Ensign, D. G. Cash, O. F. Bay, J. Kajander.

H pe Iron I and Company, Chicago, 111.; $25,000; 1.000 shares; Dec. 21, 1889. L. Silverman, J. Frank, E. Haitmann, L. Moss, L. F. Minzesheimer.

Ida C. Mining and Milling: Company, Minneapolis; $500,000; 250,000 shares; Aug. 22, 1889. W. H. Middlemist, M N. Price, A. D. Westby.

Imperial Gold Mining: Company, Minneapolis; $1,250,000; 125,000 shares; April 27, 1885. R. W. Johnson, W. Baker, E. H. Strong, J. H. Baker, N. fl. fiemiup.

Iron Dollar SUver Mining: Company, St. Paul; $2,500,000; 250,000 shares; Sept. 12, 1887. J. H. Murder, E. F. Mues, O. T. Newcomb, C. W. Eber- jein, J. R. Foulke, J. E. SheriD, A. Donald.

Iron Ore Mining" Company, Minneapolis; $1,000,000; 40,000 shares; April 19, 1887. E. W. Hand, M. V. Little, F. H. White, E. J. Swan .

lr<n Fiver Brown Stone Company, Duluth; $100,000; 2,000 shares; Feb. 27, 1890. J. F. Fredin, O. W. Wilson, J. F. Gargill, B. L. Peterson, A. Broman.

Ironton Steel Company, Duluth; $1,000,000; 10,000 shares; Aug. 20, 1890. F. Barrett, G. A. Atkins, F. B. Williams, J. J. Sullivan, J. L. Wylie, C. W. Boyd, W. Duffey, J. J. Bright, J. P. Morrow.

Jefferson Silver Mining Company, St. Paul; $500,000; 100,000 shares; Oct. 26, 1882. A. De Graff, L. D. Hodge, E. S. Goodrich.

Jordan Mining: Company, Jordan: $250,000; 2,500 shares; Dec. 8, 1887. F. Nicolin, H. Nicolin, W. W. Knott, C. Erickson, P. Rich, J. H. Nicolin, H. Hartwig, M. M. Shields, F. Nicolin, Jr , et al.

Judith Mining Company; St. Paul; $100,000; 1,000 shares; May 2?* 1885. A. DeGraff, E. N. Saunders, S. S. Eaton, H. L. Moss, W. S. Alexander

Kkabeka Gold and Silver Mining: Company; Minneapolis; $2,000,000; 200,0(0 shares; May 5, 1888. C. Sunderland, A. C Dunn, F. J. Bletcher, O. N. Murdock, H. M. Murdock, R R Knapp, E. E. McDonald.

Knministiquia Iron M: Company; St. Paul; $2,500,000; 100,000 shares; Dec. 14, 1887. O. N. Murdock, W. Murdock, V. Bowerman, A. F. Olmsted, G. M. Smith, E. E. McDonald.

Kettle River Sandstone Company; St. Paul; $250,C00; 5,000 shares; Sept. 16, 1887. W. H. Grant, J. P. Knowles; J. Hurley, F. A. Hodge.

1 ake I on Mining: Company; St. Paul; $1,000,000; 40,000 shares; March 12, 1887. F. M. Ferris J. D Cameron, R G. Baldwin, O. Martin, W. S. Reynolds, C. B. Walker, W. W. McDonald, C. B. Harvey, et al

Lebigh Coal and Iron Company; St. Paul; $500,000; 5,000 shares; April 30, 1886. O. W. Griggs, A. G. Foster, J. li. Lewis, A. G. Yates.

Lincoln SHer Mining Company; Minneapolis; $200,000;

shares; Oct. 26, 1880. W. Windom, O. O. Jones, C. M. Loring. R S. Jones, H. M Goodhue, G. J. Goodhue, A. 0. Loring, G. L. Scott, J. E. Miner.

Iron Ores Of Minnesota 341

Lochiel Iron Mining Company; St. Paul; $1,000,000; 100,000 shares. July 25, 1887. P. H. Rasohe, O. 0. Fairchild, W. J. O'Brien, J. F. Beinlein, O; H. VanAuken.

Lone Hand Mlnint? Company; St. Paul; $1,500,000; Aug. 6, 1887. H. B. Willis, H. P. tfall, E. W. Johnson, E. L. Corning, C. C. Perkins, J. AL Oilman.

Longyear Mesaba Land and Iron Company; Jackson, Mick; $500,000; 20,000 shares; Deo. 10, 1887. J. M. Longyear, J. M. Case, C. 0.. Bloomfield, A. B. Robinson, D. S. Smith, H. H. Smith, Henry H. Smith, W. H. Withington, A. M. Walker, et al.

Lumberman's Mining Company; Stillwater; $1,000,000; 40.000 shares; May 28, 1887. C. E. Mosier, L. Clarke, C. Oonham. E. J. Rowly, R. Fitzgerald, J. A. Abraham, W. P. Brown.

Lnverne Granite Company: Lnveme; $200,000; 2,000 shares; Feb. 13, 1886. B. C. Richards, C. H. Wynn, B. L. Richards, O. A. Wynn.

Macomber Mining Company; Duluth; 81,000,000; 100,00') shares; Deo. 5, 188a J. A. Willard, G. F. Piper, M. G. Willard, C. Markell, H. W. Coffin, C. E. Shannon, A. L. Warner, W. C. Sherwood, T. B. Mills.

Madiflon Mining and Reduction Company; Minneapolis; $1,000,- 000; 10,000 shares; Aug. 12, 1887. J. B. Atwater, A. B. Jackson, G. C. Ripley, C. K Davis, E. S. Goodrich, D. F. Morgan, N. D. Johnson.

Mallmann Iron Mining Company; Duluth; $600,000; 60,000 shares; July 19, 1890. A. H. Viele, A. J. Trimble, F. L. Cowen.

Mankato Coal Oil and Mineral Com nan y; Mankato; $50,000; 1,000 shares; Jan. 14, 1887. P. Zimmerman, J. L. Ritter, G. E. Spotz, J. Hagen, P. A. Larson, W. P. Marston, C. E. Davis, E. Weaver, et al.

McNaughton Mining Company Duluth: $160,000; 1,600 shares; Oct 16, 1886. jTF. Baars, Jr., J. D. Howard, W. O. Huhart, Jr., J. D. Ensign, R. McNaughton, W. J. Nelson.

Merrill Discovery Company; Minneapolis; $15,000; 150 shares; Jan. 12, 1882. R. S. Innes, R D. Russell, G. B. Kirkbride, T. G. Merrill, G. H. Keith, H. M. Goodhue, A. F. Elliot.

Merritt Mining and Milling Company; Minneapolis; $150,000; 150,000 shares; July 1, 1885. R. B. Langdon, A. H. Linton, A. D. Coon, W. J. Hahn.

Mesaba Gold and Silver Mining Company; Rochester; $70,000; l,400shares; Aug, 29, 1866. G. W. Baker, O. P. Stearns, 8. Risker, O. P. Whit- oomb, E. O. Jones, A. Gooding, C. H. Morrill, C. C. Jones, C. S. Younglove.

Mesaba Iron Company; Duluth; $3,000,000; 100,000 shares; June 14, 1882. W. W. Spalding, H. P. Wieland, A. Ramsey, W. Harris, W. D. Williams, Im Stannard, J. Mercer.

Michigan Mining and Developing Company; Duluth; $1,000,000; 40.000 shares; Nov. 5, 1887. Neil Molnnis, E. W. Mee, L. D. Cyr, W. J. Adams, J. Bale.

Minneapolis and Black Hills Mining Company; Minneapolis; $1,500,000; 800,000 shares, Nov. 14, 1887. H. W. Carter, F. W. Reed, A. L. Loomis, E. D. N. Whitney, J. Hildreth, I. A. Oisen, M. O. Little.

Minneapolis and Gogebic Mining and Milling Company; Min- neapolis; $1,000,000; 200.000 shares; Nov. 21, 1888. I. J. Cox, W. H. Midde- miet, A. D. Westby, D. F. Strobeck.

Minneapolis and Malaga Gold and Silver Mining Company; Minneapolis; $1,250,000; April 12, 1888. R. J. Anderson, W. P. Douglas, J. M. Anderson.

342 Bulletin No. Vi.

Minneapolis Mica Mining* Company; Minneapolis; 8250,000; 2,500 shares; July 16, 1884. P. B. Christian, R. H. Hawkinson, A. F. Scott, P. S. Janney, M. C. Chapman.

Minneapolis Mining: and Milling Company; Minneapolis; 930,000; 1,200 shares; Sept. 28, 1877. J. L. Pomeroy, 0. B. Severance, S. P. Hawley, D. A. Tinkelpaugh.

Minneapolis Mining and Milling Company; Minneapolis; $2,500,- 000; 100,000 shares; Oct 17, 1884. M. A. Morey, V. Truesdell, A. A. Camp, R. F. Hurlburt, H. W. Armstrong.

Minneapolis Mining and Smelting Companv; Minneapolis; 82,- 500,000; 500.000 shares; Sept. 22, 1885. P. W. McAdow, J. R. Anderson, E. S. Case, J. V, Nye, G. D. Emery* E. J. Davenport, 0. P. Chapman.

Minneapolis Mining avid Exchange; Minneapolis; Dec. 7,

1889. J. Hildreth, A. F. Olmsted, H. A. Turner, W. N. Viguers, J. R. Jones, C. J. Robertson, G. W. Cooley, R. L. Pratt.

Minneapolis Mining, Smelting and Refining Company; Minne- apolis; $50,000; Jan. 30, 1888. W. E. Steele, A. J. Blethen, A. J. Board man.

Minnesota and Wisconsin Stone Company; Minneapolis; $200,000; 4,000 shares; Feb. 5, 1886. E. H. Steele, C. C. Dunn, W. H. Hubbard, D. J. Spaulding, W. J. Thompson.

Minnesota Gold Mining Company: St. Paul; 82,000,000; 100.000 share*; Nov. 22, 1865. H. M. Rice. H. M. Sibley, F. Steele, S. Miller, J. S. Prince, W. J. Cullen, R. Chute, S. H. Chute, W. W. Webb, J. E. Thomson. C. H. Oakes.

Minnesota Granite Company; St. Paul; 815,000; 300 shares; Nov. 27, 1867. W. F. Davidson, W. A. Spencer, A. H. Wilder, H. L. Carver, H. B. Big. low.

Minnesota Iron Company; St Paul; 820,000,000; 200,000 shares; Nov. 14, 1882. 0. Tower, E. Breitung, G. C. Stone, C. Tower, Jr., R. H. Lee.

Minnesota Lake Manitan Gold and Silver Mining Company;

Benson ; $2,000,000; 1,000,000 shares; Aug. 14, 1884. T. Knudson, 1. F. Young, G. Camden, T. J. Berjerson, H. Mercie, J. Ward, P. J. Johnson, et al.

Minnesota Mining Company; Monticello; $100,000; 2,000 shares; July 20. 1886. H. L. Brazie, C. W. Boyd, J. N. Stacy, D. A. Melrose, W. M. Mel- rose, T. Melrose, A. Y. Eaton.

Minnesota Mining Company iDuluth; 8600,000; 6,000 shares; May 28,

1890. fl. B. Moore, W. T. Bailey, W. B. Parsons, F. B. Kellogg, C. A. Severance,

Minnesota Natural Gas, Oil and Fuel Companv; Albert Lea; $1,500,000; 30,000 shares; Aug. 24, 1887. W. P. Sergeant, R. M. Todd, E. S. Prentice, D. F. Morgan, J. P. Hovland, C. C. Dwight, W. C. McAdam, J. H. Parker, T. V. Knatvold.

Minnesota Plumbago Company; Minneapolis; 81,000,000; 40,000 shares; Feb. 10, 1888. M. J. Merrill, R. J. Baldwin, E. Russell, O. H. Tyler.

Minnesota Valley Gold and Silver Mining Company; Granite Falls; 8250,000; 10,000 shares; July 24, 1889. E. O'Connor, J. O'Connor, E. F. Rowe, T. A. Mellermoe, T. O'Connor,

Missouri Cannel Coal Mining Comoany; St. Paul; $500,000; 5,000 shares; April 30,1888. L. S. Chaffee, B. R. Co wen, H. C. Weakley, F. E. Weakley, J. W. Baker, W. W. Braden, G. F. Hamilton.

Mokoman Mining Company; Lake county; 8500,000; 10,000 shares; Sept. 9, 1864. E. Sales, J. P. Coulter, A. A. Parker, W. D. Williams.

Monarch Hydraulic Mining Company ; St. Paul; $1,000,000; 100.C0O shares; Jan. 17, 1887. H. W. Carter, 0. A. Gridler, J. M. Oilman, M. D. Mann.

Iron Ores Op Minne80Ta. 343

Monitor Mining Company; Lake county; $500,000; 10,000 share?; Sept. 9, 1864. A. Doolittle, J. Bentonshow, J. W. Orozer, A. A Parker, W. D. Wil- liams,

Monongahela County Agricultural and Mineral Society; Jan. 18, 1867. J. Tuttle, J. S. Whitla, C. E. Lien.

Montezuma Gold Mining Company; Minneapolis; $1,000,000; 100,000 shares; June 22, 1886. D. Ryan, S. E. Dawson, H. Matt son, L. Jaeger.

Mo g*n Mining and Reduction Company; Minneapolis; 825,000; 250 ahares;Aug. 12; 1887. J. B. Atwater, A. B Jackson, G. C. Ripley, C. K. Davis, E. S. Goodrich, D. F. Morgan, N. D. Johnson.

Mountain Iron Comnany; Duluth; $2,000,000; 20,000 shares; July 10, 1890. L. Merritt, J. T. Hale, R. H. Palmer.

Mountain King Mining Association; Winona; 81,500,000; 60,000 shares; April 2, 1881. F. A Johnston, E. M. Wilson. W. F. Phelps, C. H. Berry, C J. Johnson, L. R Brooks, E. G. Perkins, C. L, Coleman, S. Y. Hyde, C. L. Bonner, W. W. Oargill.

Mountain Range Tron Company; Duluth; 8.50,000; 500 shares; May 31, 188a L. Merritt, A. Merritt, C. C. Merritt, E. D. Chase, C. Chambers.

Mouse River Land Company; Minneapolis; $60,000; 100 shares; Jan. 26, 18S5. J. A. Bowman, C. E. Brown, C. P. Huseltine, W. H. Mitchell, M. H. Raymond.

Neptune Gold Mining Company; Minneapolis; $750,000; 7,500 shares; Dec 10, 188a R J. Anderson, W. P. Douglas, H. C. Hanford.

New Ulm Stone Compmy; New Ulm; $25,000; 250 shares; Dec. 24,

1888. W. Boesob, G. G. Benz, A. Schell, J. Pfeuniuger.

New Vienna Mining Company; $500,000; 20,000 shares; Nov. 16,1888; a L. Coleman, H. J. O'Neill, F, A. Johnston, S. Y. Hyde, W. W. Cargill.

Nicollet Mining Company; Minneapolis; $2,500,000; 250,000 shares; March 8, 1887. E. J. Davenport, G. D. Emery, J. V. Nye.

Norman Iron Company; Chicago, III; $50,000; 2,000 shares; April 13

1889. R Spencer, A. C. Ely, J. W. Chandler.

North Dnkota Coal Mining Company; St. Paul; 8200,000; 4,000 shares; Sept. 18, 1883. N. 0. Deerin*, J. B. C'eland, W. L. E tton, F. F. Coffin, P. H. True, W. A. Kirkham, J. T. Standrin*, L. Standring, T. W. Burdick, M. V. Richards.

North east Minnesota Mining Company; Minneapolis; $2,500,000; 100,000 shares; April 27, 1887. A. C. Bruce, J. G. Emery Jr., J. Paulson.

Northern Gold Company; Minneapolis; $40,000; 400 shares; April 22, 188a W. A .DellPlain, P. K. K. Paulson, J. H. Cates.

North Shore Consolidated Silver Mining Company; St. Paul; $600,000; 20,000 shares; Nov. 1, 1878. W. J). Washburn, A. H. Wilder, W. Lee,A. DeGraff, 0. A. Morton, G. Culver, A. Wharton, O. P. Whitcomb, G. L. Moore, J. H. Baker, J. F. Magher.

North Shore Gold and Sliver Mining Company; St. Paul; $2,000,- 000; 200,000 shares; Feb. 11, 1888. O. N. Mnrdock, C. A. Stinson, H. S. G. Gnswell, J. M. Lynch, F. J. Bletcher, G. B. Shaw, G. H. Browne, A. F. Olm- .

North Shore Mining Tompanv; Duluth; $100,000; 2,000 shares; Aug. 18, 1863. R T. Paine, H. B. Paine, R B. Carlton, E. S. Goodrich, G. L. Becker.

North Shore Mining Company; Detroit, Mich.; $1,000,000; 40,000 shares; May 24, 1888. W. P. Spalding, H. F. Eberts, R R Paulison.

344 Bulletin No. Vi.

North Shore Silver and Copper Mining" Company; Duluth; $2,500,000: 100,000 shares; April 15, 1884. B. B. Spalding, J. McBelh, E. W. WakeliD, J. Buttle, J. S. Daniels, J. S. Crawford, S. H. Seelye, W. Dunlap, W. B. Gahan, M. Paine, J. E. Knowlton, H. H. Hawkins.

North Star Gold and Silver Mining' Company; Minneapolis; $60,- 000; 1,200 shares; Feb. 20, 1866. J. M. Waldron, T. M. Linton, B. P. Russell, G. A. Brackett, P. Gibson.

North Star Jrn Land Company; Duluth; $100,000; 4,000 shares; March 14, 1887. L. Silverman, J. Frank, B. Moos, £. Hartmann, R. Mallet.

North Snperior Iron Mininer Company; Dnluth; $1,000,000; 40,000 shares; April 23, 1887. W. W. Spalding, H. M. Francis, F. W. McKinley.

Northwestern Coal Mininer Company; Minneapolis; $1,000,000! 40,000 shares; March 23, 1888. W. E. Jones, W. C. Jones, C. W. Jones, F. H-

Remington.

Northwestern Gold and Silver Mining: Company, of Minnesota; St Paul; $500,000; 10,000 shares; Jan. 5, 1865. 0. E. Davis, J. W. Webb, J. H. Place, J. McGraves, T. Ranck, J. Condit

Northwestern Mining" Company; Minneapolis; $10,000; 200 shares; Dec. 23, 1884. H. N. Farnam, Carrie H. Farnam, H. G. Cable.

Northwestern Mining: Exchange; St. Paul; $27,000; 270 shares; April

19. 1887. G. D. M. Sherman, H. S. Chase, M W. Gasser, F. J. Bletcher, H. W. Wack, H. L. Bryant, M. M. Metcalf, H. L. Wheat, B. M Bicksler.

Northwestern Natural Gas, Oil and Mining: Company ; St. Panl; $500,000; 5,000 shares; March 17, 1887. F. J. Oleminger, W. G. Hunter, H. Brawley.

Oil, Gas and Water Well-Drilling Company; St. Paul; $50,000; 500 shares; Feb. 28, 1890. H. Barton, D. N. Harris, J. 0. Barton, S. A. Anderson, S. T. Conkhng.

Old Veteran Miring: Company; Minneapolis; $1,000,000; 80,000 shares; Oct. 4, 1888. J. P. Nichols, R. R. Henderson, A. F. Nichols, G. H. Simpson, E. Nichols, C. W. Tracy, W. E. Hale.

Omega Iron Company; Minneapolis; $800,000; 80,000 shares; May 27> 1887. D. D. Jones, F. V. Darrow, J. C. Jones, E. Gjertsen, I. L. Moore, B. H. Hellen, N. Goff, G. W. Williams.

Oneota Gold and Silver fining Company; Duluth; $1,000,000; 500,000 shares; April 2, 1884. A. E. Sears, J. Mallech, E. Lightheart.

Ontario Silver Mining Company; St. Paul; $2,000,000; 400,000 shares; June 1, 1887. E. H. 0. Taylor. A. F. Russell, V. C. Oilman, A. K. Murray, W. J. Stevenson, T. Tyrer, R. M. Fulton.

Ontario Syndicate Mining Companv; St. Paul ; $1,000,000; 100,000 shares; Deo. 30, 1887. J. H. Bur well, M Auerbach, E. G. Rogers, T. Sauls- paugh, H. P. Breed, R. B. Galusha, H. Sahlgaard.

Oriental Granite and Iron Company, Duluth; $1,000,000; 40,000 shares; April 23, 1887. L. Silverman, J. Frank, B. Moos, E. Hartmann.

Philadelphia Gold Mining: Company; Minneapolis; $600,000; Nov.

19. 1888. C. A. Sparks, E. V. Douglas, R. Wetherill, Richard Wetherill, W. P. Douglas.

Pigeon River Mining: Company; Duluth; $250,000: 10,000 shares; May 17, 1883. 0. J. Bower, W. Warner, W. M Lenhart, G. F. Schutt, M. E. Chambers.

Pioneer Exploration and Mining Company; Duluth; $1,000,000; 40,000 shares; July 23, 1888. J. T. Gregory, J. S. Ellis, W. H. Phippa, J. A. Hum bird, J. H. James.

Iron Obb8 Of Minnesota. 345

Pioneer Gold and Silver Mining" Company, of Minnesota; St. Paul; $600,000; 10,000 shares; Aug. 10, 1866, T. M. Newson, H. M. Lamborn, I. N. 8teele, et al.

Pioneer tron Mining: Company; Duluth; $1,000,000; 40,000 shares; July 16, 1886. E. J. Palmer, J. T. Gregory, J. a Ellis, N. I. Willey, J. H. James.

Pipestone Quarrying: Company; Pipestone; $250,000; 5,000 shares; June 6, 1884. E. K. Wall bridge, L. H. Moore, H. E. Corbett

Pleasant River Gold Mining Company; Minneapolis; $100,000; 10,- 000 shares; Jan. 24. 1887. S. Leavitt, S. L. Baylies, 8. Schreiber.

Portland Stone Company ; St. Paul; $50,000; 500 shares; Nov. 14, 1885. P. Berkey, J. A. fierkey, W. P. Cockey, L. Washington.

Potter Mining, Smelting- and Refining: Company; Minneapolis; $500,000; 20,000 shares; Maroh 1, 1887. J. West, C. E. Baldwin, R. Bruce, R Ii. Penney, T. G. Merrill, W. D. Pinkerton.

Premier Pet Company; St. Paul; $300,000; 6,000 shares; Deo. 17, 1867. C H. Oakes, 0. D. W illiams, M. R. Jefferds.

Queen Gold and Silver Mining and Milling Company: St. Paul; $1,500,000; 300,(00 shares; April 14, 1887. H. S. Sibley, 0. G. Kimball, J. A. Bosk, J. H. flullsilk, A. H. Truax, J. Q. Haas, A. C. Ramsden.

Rainy Lake Mining: and Improvement Company; Duluth; $100,- 000; 100,000 shares; Oct 23, 1890. L. S. Franklin, A. Thompson, J. H. Norby, C. W. Ericson, B. Fenstad, J. A. Rowneng, W. Ericsoa.

Bawdon Gold Mining: Company; St. Paul; $250,000; 2,500 shares; Aug. 30, 1886. E. C. Long, A. D. McLeod, G. Graham, E. A. Long* J- Graham.

Red Pipestone Quarrying Company; Pipestone; $50,000; 500 shares; Oct. 24, 1889. J. M. Poorbaugh, T. A. Black, E. W. Davies.

Redwood Coal Company; St. Paul; $10,500; 210 shares; Oct. 12, 1864. H. H. Sibley, J. S. Prince, F. Steele, 0. H. Oakes, H. M. Rice.

Richmond Mining Company ;_Richmond; $10,000; 400 shares; March $, 1880. J. Simonitsch, J. Schneider, Berghoff, M. A Busson.

Kio Grande Miniug Association; Winona; $500,000; 5,000 shares; June 1, 1882. R. A. Jones, 0. C. Hughes. E. G. Stewart, J. F. Read, D. B. Burdette.

River Iron Mining Company; St. Paul; $1,000,000; 40,000 shares; March 12, 1887. F. M. Ferris, J. D. Cameron, R. G, Baldwin, H. C. Masters, W. S. Reynolds, C. B. Walker, 0. A. Greeley, et al.

Sage-Emery Mining Syndicate; Minneapolis; $2,500,000; 100,000 shares; April 27, 1887. J. G. Emery, T. Emery. V. W. Bayless.

Sand Coulee Coal Company; St Paul; $250,000; 2,i00 shares; July 27, 1888. W. P. Clough, M. D. Grover, E. Sawyer.

Paiik River Mining Company; Richmond; $200,000; 1,000 shares; Sept 25, 1871. H. P. Daendels, J. Eder, W. Erdman.

Sault Ste. Marie Quarrying and Mining Company; Minneapolis;

$5X1000; 1,000 shares; April 3, 1889. A. M. Jordan, W. G. Tice, C. M. Jordan, T. W. Hammond.

Sharp Iron Mining and Smelting Company; Minneapolis: $1,500,- 000: 60,000 shares; Sept 28, 1887. L. M. Sharp, T. H. Monahan, E. H. Page, J. F. For je, H. Byrnes, R. E. Trafton, F. Murdock.

Sheridan Iron Company; St Louis county; $1,000,000; 10,000 shares; Sept, 27, 1887. H. & Piokands, W. L. Brown, J. H. Chandler.

Sentinel Gold Mining Company; Minneapolis; $750,000; 75,000 shares; Bee. 22. 1884. N. H. Hemiup, A. P. Walrath, S. H. Baker, A. A. Camp, R. F. Hurlburt

346 Bulletin No. Vi.

Silver and Copoer Island Mining Company, of Minnesota; St. Paul; $2,000,000; 1,000,000 shares; Jane 14, 1882. J. N. Stewart, C. G. Kimball,

C. A. Heffelfinger, W. A. Kindred.

Silver Bell Mining: Company; Rochester; 8200,000; 2,000 shares; July 26, 1881. G. W. VanDusen, R A. Newton, C. H. Chadbourne, A. Gooding, H. T. Hannon, L. E. Cowdery, A. Harrington, S. E. Newton, C. VanOampen.

8ilver City Mining: Company; Duluth; 81,000,000; 100,000 shares; Nov. 22, 1884. D. T. Adams, J. Evans, J. A. Stookbridge, J. M. Sharp, G. Anderson, A. P. Dodge, O. W. Fish, T. A. Bury, J. D. Howard. (Company dissolved by order of court).

Silver Lake Mining Comnany; Duluth; $2,000,000; 200.000 shares; April 27, 188a A. D. Cummings, H. R Tinkham, J. H. Hillyer, E. Tinkham.

Silver Lead Mining: Company; St. Paul; $1,000,000; 200,000 shares; Feb. 23, 1889. O. A. Turner, E. B. Northrop, 0. C. Mister. (Moved to Montana).

Silver Ore Mining: Company; St. Paul; 850,000; 5,000 shares; June 17,

1885. F. Wilde, 0. Faber, A. Barmann, M. Toltz, J. W. Gandsay, J. C. Simonet, et al.

Silver Star Mining: Company; Stillwater; $1,200,000; 48,000 shares; Oct. 12, 1887. R S. Davis, E. W. McClure, J. W. Shupp, A. G. Triebel, et al.

Sixty-Three Twelve Iron Land C mpanv; Duluth; 81,000,000; 40,000 shares; Oct. 8, 1887. L. Silverman, J. Frank, B. Moos, E. Hartmaun, R. D. Mallet.

Solid Gold and Silver Mining Compwv; Minneapolis; 8#)0,000; 40,000 shares; May 24, 1883. J. C. Phillips, 0. E. Whelpley, C. E. Oonant, N. H. Hemiup, L A. Barnes, S. H. Wood, W. D. Haycock.

South Superior Gold and Silver Mining and Milling Company;

Minneapolis; $250,000; 250,000 shares; Aug. 19, 1890. S. Parker, E. E. Blinn, M. N. Price, J. L. Parker, A. D. Westby.

South Washburn Mining and Smelting Company; Minneapolis; 81,250,000; 50,000 shares; Feb. 16, 1888. A. D. Westby, D. F. Strobeck, C. B. Holmes.

Standard Gold Mining and Milling Cimpauv; Minneapolis; 82,000,000; 200,000 shares; Nov. 29, 1890. J. C. Stout, H. D. Stocker, R. T. Lang, G. L. Matchan, N. Galles, M. Thompson.

Stanton Miuing Company; St. Paul; 8100,000; 10,000 shares; Dec. 1,

1886. 0. M. Ramsey, H. C. Davis, W. S. Alexander, R B. Galusha, A F. Hughes.

S . CI oud Granite Quarrying and Manufacturing Company;

St. Paul; 8100,000; 2,000 shares; Aug. 16, 1875. H. Rogers, W. M. Tileston,

D. W. Wellman, W. D. Rogers, L. A. Evans.

Stillwater Mining Company; Minneapolis; 8800,000; 16,000 shares; Sept. 22, 1885. J. V. Nye, P. McAdow, J. Anderson, E. S. Case, G. D. Enery,

E. J. Davenport, C. P. Chapman.

Stillwater Mining Company; Minneapolis; 81.000,000; 400,000 shares April 29, 1887. P. Potts, L. P. Richardson, G. H. Atwood, A. M. Dodd, E. A. Phinney, W. A. Chambers, O. A. Watier.

St'Il water Natural Gas and Oil Company; 850,000; 10,000 shares; Deo. 1, 1887. E. W. Durant, J. MoOusick, D. Tozer, A. K Doe, J. C. Nethaway.

St. Louis Iron Mining Company; Duluth; 81,000,000; 100.000 shares; March 28, 1887. R. H. Lee, I. P. Beck, A. J. Whiteman, A. H. Viele, W. B. Dixon, C. B. Woodruff.

Iron Company; Duluth; 8600,000; 60,000 shares; April 26, 1890. G. C. Stone, J. Sell wood, J. B. Geggie.

Ibon Obes Of Minnesota. 347

Stonewall Wining Company: St. Paul; 82,500.000; 100,000 shares; Feb. 6, 1881 D. Schutte, J. M. Pottgieser, S. Dearing, K. B. Galusha, W. 8. Alexander, J. Hill, W. H. Fisher.

8t. aul and Black Hills Gold Mining Company; St. Paul; $50.- 000; 2,000 ebaree; March 22, 1877; A. H. Merrick, O. D. Williams, W. S. Alexander, T. Brennan, G. Messer, T. M. Newson, 0. R. Groff, N. Meyrick.

St. Paul and Dunn County Mining Corporation; St. Paul; $500,- 000: 20,000 shares; June 22, 1887. E. S. Norton, P. J. Schmitz, T. C. Hand, J. M. Bohrer, A. Boldigheimer.

St. Paul and Pacific Coal and Iron Company; St. Paul; $100,000; 1,000 shares; Ang. 80, 1883. H. Pratt, L. C. Hanna, A .

St. Paul Clay and Mining Company; St. Paul; $10,C00; 200 shares; Hot. 19, 188a J. 0. Stiokney, R. C. Wight, W. M. Jones.

SulMvan Tron Company; Dulnth; $50,000; May 19, 1890.

J. T. Hale, J. M. Smith, H. W. Coffin, J. T. Snively, 0. P. Craig, S. F. Wadhams.

8nmmit Mining and Smelting Comnany; St. Paul; $2,500,000; 250,000 shares; Feb. 27, 1888. E. H. Smith, A. F. Stewart, E. S. Case, H. A. Thompson, H. S. Potts.

Swan Iron Mining Company; Minneapolis; $1,000,000; 40,000 shares; Jan. 29, 1887. E. J. Swan, G. W. Payne, E. A. Sumner.

Swart Gold and Silver Mining Company; Wabasha; $500,000 20,000 shares; Deo. 27, 1887. G. H. Swart, C. Jellison, W. M. McDonald.

Taylor's Falls Copper Mining Comnany; Taylor's Falls; $200,000; 2tV*K) shares; Deo. 6, 1874. W. H. C. Folsom, G. W. Seymour, T. W. Folsom, J. L. Taylor, D. A Caneday, C. Hanser, J. Schottmnller.

Temperance River Silver and Copper Mining Company; Duluth;

Feb. 9, 1884. S. H. Seelye, J. E. Knowlton, J. A. Mannheim, J. F. Baars, Jr., F. W. Paine, M. Thomas, J. C. VanNorman.

Thunder Bay Gold and Silver Mining Company; St. Paul; $2,000,- 000; 200,000 shares; April 4, 1889. R. L. Wharton, C. A. Stinson, F. M. Cady, R F. Marvin, J. J. Dougher, C. B. Marvin, J. R. Mansfield, T. J. Willbeck, A.

F. Olmsted, et ah

Union Gold and Silver Mining Company, of Minnesota; St. Paul; $600,000; 10,000 shares. Aug 10, 1866. T. M. Newson, G. P. Harris, etal.

Union Iron Company; Duluth; $4Q0,<00; 40,C00 shares; Jan. 30, 1889; J. H. James, J. Megins, W. C.Sherwood, A. J. Lonstorf, J. Bale.

Union Iron Milling Company; Duluth; 81,000,000; April 6, 1887. J. Paulson, W. W. Spalding, J. D. Strjker, F. W. McKinney, H. M. Francis.

Union Mining, Smelting and Refining Company; Duluth; $1,0C0,- 000; 10,000 shares; Jan. 19, 1887. O. P. Stearns, C. H. Graves, 0. Markell, D.

G. Cash, J. D. Ensign.

Union Quartz Mining and Milling Company; Winona; $300,000; 8,000 shares; Dec. 19, 1881. 0. JL. Colman, A. De Graff, F. A, Johnston, A. D. Ellsworth; H. J. O'Neill.

U. 8. Mining and Milling Company; Minneapolis; $250,000; 250,- 000 shares; Deo. 4, 1890. A. B. Trombly, G. W. Robinson, H. Shear, C. J. Woodward, C. E. Moore, G. H. Eastman, A. F. Olmsted.

Vermilion and Grand Marais Iron Company; Duluth: 85,000,000; 600,000 shares; Dec. 11,1888. H. W. Sibley, D S. Fox, I. Benriuger, H. M. Loud, G. T. Walker, 0. S. Brown, W. McKinley, F. W. Paine, H. Williston, et al.

Vermilion Palls Gold Mining Company; St, Paul; $300,000; 6,00 shares- Nov. 8, 1865. O. E. Dodge, E. A. Dodge, C. D. Gilfillan, J. Gilfillan, Q D. Williams.

348 Bulletin No. Vi.

Vermilion Iron and Land Company, of Duluth; Duluth; 81,000,000; 100,000 shares; March 26, 1888. J. W. Achom, A. H. Holgate, G. T. Johns, W. H. SmallwoocL

Vermilion Iron Mining and Improvement Company, of St. Paul; St. Paul; $2,500,000; 100,000 shares; Aug. 12, 1887. O. L.Taylor, O. E. Millis, P. D. Youngman, W. L. Lamb.

Vermilion Land and Iron Syndicate; Duluth; $3,000,000; 750,000 shares; March 23, 1887. W. W. Sp4ding, H. K. Bell, P. W. McKinney, BL M. Francis, J. Paulson, B. J. Wemyss, 0. H. Arthur.

Vermilion Mining- Company; Duluth; $1,000,000; 40,000 shares; Jan. 17, 1887. J. B. Myers, H. H. Myers, B. F. Myers.

Vermilion Range Iron Cunppny; Duluth; $1,000,000; 100,000 shares; Nov. 5, 1887. C, E. Shannon, J. M. Mc Kinley, J. A. Willard, G. F. Piper, W. Foulke.

Vermilion Range Iron Company; Duluth; $50,000; 500 shares; May 31, 1889. L. Merritt, A. Merritt, C. C. Merritt, B. D. Chase, 0. Chambers.

Vermilion Range Lumbar and Iron Companv; Minneapolis; $100,000; 10,000 shares; Jan. 22, 1890. L. Howland, R. W. Gilkey, C. B. Lampson, W. J. Monahan, F. C. Laird.

Vermilion Rang* Mining Syndicate; Minnwpolis; $2,500,000; 100,- 000 shares; April 27, 1887. J. G. Emery, T. Emery, J. Paulson.

Vienna Consolidated Mining Company; Winona; $675,000; 27,000 shares; March 5, 1881. E. M. Wilson, F. A. Johnston, C. J. Johnston, C. H. Berry, W. F. Phelps, O. B. Gould, C. A. Morey, 0. H. Mills, H. 0. Shepherd, E. F. Curtis, R. T. Doud, et ah

Vienna Mining Company; Winona; $15,000,000; 150,000 shares; March 23, 1882. C. L. Coleman, A. De Graff, H. J. O'Neill, A. D Ellsworth, C. H. Berry, B. H. Langley, 0. L. Bonner, F. A. J jhaston, L. Y. Hyde.

Wabasha Black Hoof Mining Company; Wabaeha; $200,000; 4,000 shares; June 29, 1867. F. Klinge, M. E. Wetherbee, J. E. Morrison, A. W. Ditmars, J. Crowley, D. Schutte, 8. Lyon.

Wabasha Mining Company; Wabasha; $500,000; 20,000 shares; Sept 5, 1887. J. H. Mullen, C. Jellison, G. H. Swart

Washburn Mining and Milling Company; Minneapolis; $1,000,000; 200,000 shares; July 26, 1888. W. H. Middlemist, A. D. Westby, D. F. Strobeck.

Wasioja St me Company; Dodge Centre; $60,000; 1,200 Phares; Feb. 21, 1889. J. A. Green, W. B. Parsons, W. E Richardson, F. C. A. Day.

War Eagle Gold and Silver Minin&r and Milling Company;

St. Paul; $2,500,000; 250,000 shares; Feb. 21, 1888. J. M. McCafferty, E. A. Fitzgerald, M. Treacy, P. Durack, E. Kelley, J. Norton, et al.

Watab Gold and Silver Miiing Company; St Paul; $500,000; 10,000 shares; Sept. 25, 1867. C. D. Montreville, T. M. Newson, J. Gilman.

Waterloo Iron Mining and Smelting Company; Minneapolis* $1,500,000; 60,000 shares; March 28, 1888. J. Buhe, L. Matthews, E. Munger;

Watertownand La Crosse Go'd and Silver Mining Company;

Minneapolis; $500,000; 10.000 shares; June 30, 1866. 1. 1. Lewis, S. M. Tarvin, L. Brandt, W. B. Ellis, H. J. McKee, E. Hamlin, D. M. Lusk, C. V. Kiagsley, M. M. Ryan, W. F. Robinson.

Western Transportation and Mining Company; $100,000; 1,000 shares; May 1, 1871. (Changed into Lake Superior and Puget Sound Com- pany). A. Coburn, R. Coburn, R. D. Bice..

West Superior Iron and Steel Company; St Paul; $2,500,000; 25,000 shares; May 8, 1888. B. L. Belknap, F. H. Weeks, B. J. Wemyss. J. F. Oakes, H. W. De Forest, J. Roosevelt, J. B. Williams, J. H. Ames.

Ibon Ores Of Minnesota. 349

Whitefish Take Mining: and Manufacturing" Company; Duluth; $1,500,000; 150,000 shares; Deo. 30. 1884. J. H. Caldwell, T. F. McGowan, A. Fraser, E. Jordan, N. Thomas, H. O. Kendall, 0. J. Bower, Q. Bruette.

White Iron Lake Iron ant "Water Power Company; Dulnth; $1,000,000; 100,000 shares; Sept. 20, 1888. F. W. EatoD, R Fagan, H. W. Bell, E. Brown, H. M. Load, D. L. Walker, D. S. Fox, 0. S. Brown.

White Spar Mica Mining Company; Minneapolis $2,500,000; 100,000 (hares; Deo. 20. 188a £. A. Scales, R. B. Vining, C. B. Dick in 8, A. F. Olm- sted, C. B. Lawton.

White Spar Mica Company; Minneapolis; $25,000; 1.000 shares; Oct. 9, 1881. S. Chapman, E. S. Kelly, D. Olmsted, J. E. Miner, C. G. Rogers.

Wllmina Silver Mining and Smelting Company; St. Paul; $50,000; 2.000 shares; Oct. 27, 1877. A. Lewis, W. H. Schreffler, F. Moorhead, W. O. Rogers, S. E. Bright.

Winnipeg and Northwest Petroleum Company; Minneapolis; $1,000,000; 100,000 shares; Oct. 12, 1883. C. T. Gregory, F. C. Butterfieid, E. RKent

Winona County Mining Company; Dresbach; $100,000; 4,000 shares; April 17, 1880. G. B. Dresbach, E. S. Burns. G. Widmoyer, G. Johnson, W. H. Sherwood, L. Blumentritt, F. Rodolf, G. Findell, J. J. Gunther, J. M. Turner.

Wisconsin Central Mining Company; Stillwater; $1,500,0(0; 60,000 shares: July 7, 1887. M. M. Colliner, P. Potts, S. P. Riohardson, L. A. Gotts- chall, ix Albenberg, M. Albenberg, F. C. Chartrand.

Wolverine Iron Mining Company, of St. Paul; St Paul; $1,000,000; 40,000 shares: Sept 6, 1887. J. N. Smith, B. F. Ferris, G. H. Browne, H. P. Haskell, E. F. May bee, J. H. Chamberliu, C. H. Morse, W. A. Barr, et al.

Wurst Mining Manufacturing Company -St. Paul; $100,000; 2,000 shares: Aug. 27, 1885. J. H. Kneass, T. W. Teasdale, R. W. Cavanaugh, W. H. Faraham, W. W. Sly, M. Wurst

Zenith Iron Mining Company; Dulutb; $1,000,000; 40,000 shares; March 28, 1887. E. Ellis, G. C. Greenwood. J. T. Gregory, R. D. Mallet, J. H. James.

Zumbro Lead Mining Company; Wabasha; $60,000; 2,400 shares; March 15, 1868. F. Klinge, A. C. Remondino, W. Wetherbee, J. Crowley, J. E. Morrison, O. Monette, E. H. Davis.

350 Bulletin No. Ti.

Bta Lands Leased Under The Act Of The Leo Is L At It Kb Of 1889.*

To Whom Leased.

James B. Giggle

W. B. Parsons

W. B. Parsons

C. A. Severance.

C. A. Severance

C. W. G. Wilhee. ... C. W. G. Wither.. . Leonidas Merrltt. .. Leonidas Merrill... Leonidas Merrltt... Leonidas Merru'. .. Leonidas Merrltt... Leonidas Merrill. Leonidas Merrltt... Leonidas Merr.lt... George L. Bobbins.. George L. Bobbins. George L. Bobbins.. George L. Bobbins.. George L. Bobbins.. George L. Robblns. .

George L. Bobbin*. George L. Bobbins. Fannie Griffin and Anna P. Warner.

Geo. L. Bobbins

B. IT. L. JewelL... R. H. L. Jewett

E. H. L. Jewell

Fred M. Washburn. Fred M. Washburn.. Wm. A. McGunagh..

E. V. Mnndy

John Paulson

John Paulson

A.T. Naff

Andrew Myles

Andrew My

W.T.Bailey

W.T. Bailey

A. H. Barle

R. C. Judson

R. C. Judson

John J. Wheeler

Leonidas Merrill Leonidas Merrill

John A.Davis

John A. Davis

Leonidas Merrltt — Leonidas Merrltt Leonidas Merrltt

For a nummary statement

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Aug.28, 1880 . Men. 1, 1890 I Men. 1,1890

Mcb. 1, 1890 : Mch. 1, 1890 : Mch. 1,1890 : Mch. 1, 1890

Mch. 8, 1890 ' Mch. 8. 1890

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Mch. 13,1890 Mch.13,1890 Mch.13,1890

Mch.13,1890 Mch.13,1890 Mcb.15,1890

Mch. 15,1890 , Mch. 17, 1890 i Mch.17,1890 Mch. 17,1890 Mch.17,1890 : Mch. 18, 1890 , Mch. 18. 1890 . Mch, 18,1890 i Mch. 18,1890 i Mch. 18,1890 ; Mch. 18, 1890 ' Mch.18,1890 Mch.18,1890 Mch .20, 1890 i Mch.20,1890

: Mch.20,1890 Mch.20,1890 Mch.20,1890 ; Mch.20,1890 ; Mch.20,1890 ; Mch.20,1890

Iron Ores Op Minnesota.

To Whom Leased.

Leon id as Merritt Leonidas Merritt.

Stephen L. Selder Stephen L. Selder

John M. Millar . John M. Millar . R.N. Marble... B. N. Marble . . . Belle L. Marble. W. H. Estep

Morris Thomas

Morris Thomas

William H.Phipps

Emil Hartmann

Emil Hartmann

Emil Hartmann

Emil Hartmann

Emil Hartmann

Emil Hartmann

Emil Hartmann

Emil Hartmann

Robert Louden

Robert Louden

Robert Louden

John R. Howes

Parts of Sections.

D. J. Sinclair

A. H. Truax

Leonidas Merritt.

Leonidas Leonidas Leonidas Leonidas Leonidas Leonidas Leonidas Leonidas Leonidas Leonidas Leonidas Leonidas Leonidas

Merritt

Merritt

Merritt

Merritt

Merritt

Merritt

Merritt. ...

Merritt

Merritt

Merritt

Merritt

Merritt

Merritt

SEi

NEi SWi and Ni of SEi

and SEi of SEi

Lots 4, 5 and Si NWi... Lotl and NWi NEi and

EiNEi

NEi

NWi

m nw*

NiNEi

EiSWi

Lots 2, 3 and NWi of

NWi

Ni of Si

SiofNi

NWiofNWi

NEi

NWi

SWi

SEi

NEi

NWi

SWi

SEi

Ei SWi and N Wiof SWi

;Siof NWi

SEiof NEi

Ni of NEi and Ei of

NWi

of NEi and Ni of SEi

:SEi

'Lots 2, 3, 4 and SWi of

I NWi

SEiof NWi

SEiof SWi

:SEiofSEi

Leonidas Merritt

Leonidas Leonidas Leonidas Leonidas Leonidas Leonidas Leonidas Leonidas Leonidas

Merritt, Merritt. Merritt. Merritt. Merritt. Merritt, Merritt, Merritt. Merritt,

NEi

NWi

SWi

SEi

Si of Si

sNEi

NWi

SEi ' N Wi, Ni' SWi ' and SWiof SWi

Lots 1, 2, 3 and NEi of SEi

NEi

!SiofSi

SEi

NWi

SWiof SWi

NEi

iNWi

;SWi

!SEi

O

Co

3tt

3(5 M

o

M

O

M

Cd

a o

36 ' 65

16 ; 64

16 j 64

16 ' 63

2b

1e 6w 6w

Ie

oo

Mm Oo

Mm

Oo

MM mm

oo oo

Mm

oo

Mm

oo

Mm

Mm

Date.

Mch.20,1890

Mch.20, Mch.21,

Mch. Men. Mch, Mch, Mch. Mch.

21, 21, 21, 21,

21,

Mch.21, Mch.21, Mch.21, Mch. 22, Mch. 25, Mch. 25, Mch.25, Mch.25, Mch.25, Mch.25, Mch.25. Mch.25, Mch.28, Mch.28, Mcn.28,

Mch.28, Mch.28, Mch.30,

Aprl. Aprl. Aprl. Aprl. I Aprl. Aprl. Aprl. Aprl. Aprl. Aprl. Aprl. Aprl. Aprl.

1,

1, 1,

1,

1,

1,

1,

1, 1, 1, 1, 1,

Mch.20,

Mch Mch Mch Mch Mch Mrh Mch Mch Mch Mch

Of)

.so;

0<)

.29,

.21),

8W

8Jk)

Iron Obeb Of Minnesota

To Whom Leased.

AlexandT I'im/i'i1.. Th-mas IV Dirkn,. Leonldas Merrill. .

Leonldas Merritt . . Leonldaa Merritt.. Leon id as Merritt.. Leonldas Merritt..

Leonldas Merritt.. Leonldas Merritt . . Leonidas Merritt.. Leonldas Merritt. . Leonidas Merritt. .

Leonidas Merritt. . Leonldas Merritt. . Leonidas Merritt.. Leonidas Merritt.. Leonldas Merritt. . Leonidas Merritt.. Leonidas Merritt.. Leonldas Merritt.. Leonidas Merritt.. Leonldas Merritt.. Leonldas Merritt..

Leonldas Merritt. . Leonidas Merritt.. Leonidas Merritt.. Leonidas Merritt. . Leonidas Merritt.. Leonldas Merritt.. Leonidas Merritt.. Leonidas Merritt.. Leonidas Merritt. . Leonidas Merritt.. Leonidas Merritt.. Leonidas Merritt.. Leonldas Merritt.. Leonidas Merritt. . Leonldas Merritt. .

Leonidas Leonidas Leonldas Leonidas

Leonidas Leonidas Leonidas Geo. L. R.

Cass i us C.

Merritt. . . Merritt...

Merritt...

Merritt...

Merritt...

Merritt...

Merritt... ibblns — Merritt..

Parts of Sections.

SEi

Wi SWi, NEi SWi and

Lot 2

SWi

Lots), 2 and 3

Lots 3, 7, 8 and SWi of

NEi

Lotse, 10 and Ni NEi

SEi

Si NWiand Si NEi... m SWi, SWi SWi and

NWi SEi

Lot5

NEi

SEi

Lotsl, 2 and 5

Ni NEi, SWi NEi and

lot 3

NEi

NWi

SWi

SEi

NWi

NWi

NEi :

NWi

SWi

SEi

Ni NEi. SWi NEi, SEi

NWi

SWi

Wi SEi.NEi SEi.SEi

NEi

NEi

NWi

SWi

SEi

NEi

NWi

SWi

SEi

NEi ,

NWi

SWi

SEi

NEi

NWi

Lots 3 and 4 and Wi of

SWi

Lots 1, 2 and 6

NEi

NWi

SWi

SEi

SiofNi

Niof Si

WiNWi,WiSWi.. NEi

Apr. 4,1890 Apr. 6,1890 Apr. 5,1880

May 15, 1890 May 15, 1890 May 15, 1890 May 15, 1890

: May 15, 1890 i May 15, 1890 i May 15, 1890 : May 15, 1890 May 15, 1890

May 15, 1890 May 15, 1890 May 15, 1890 May 15, 1890 May 15, 1890 May 15, 1890 May 15, 1890 May 15, 1890 May 15, 1890 May 15, 1890 May 15, 1890

l May 15, 1

) May 15, 1

I May 15,1

i May 15, 1

) May 16, 1

' May 15, 1

' May 15, 1

May 15,1

May 15,1

I May 15,1

. J May 15, 1

18 May 15, 1

18 IMay 15,1:

18 iMay 15, l

18 May 15, 1

18 IMay 15, 1 18 IMay 15, 1 18 May 15, 1 18 May 15,1 18 May 15, 1 18 Mav 15. 1: 4w May IS, 1 4w .May 15, 1; 10 May 15,1; 13 iDec. 15, l;

Bulletin No. Vi.

To Whom Leased.

CasBius C. Merritt

Andrew R. Merritt — Andrew R. Merritt

Lewis J. Merritt

Lewis J. Merritt

L. F. Merritt

L. F. Merritt

J. W. Stone

J. W. Stone

Scvert M. Severtson. . . Randolph L. Frazer . . Randolph L. Frazer. . .

Thomas Griffen

Thomas Griffen

H. Mayhew

E.W. Wakelin

Loi mi' las Merritt

H. M:ittsonandH.Bus- trom

L. T. Watson .

NWi

SWi

NEi

SEi

NWi

SWi

SEi of NWi

Niof NEi

m NWi, Lots 1 and 2. .

NWi SEi and Lot 6

SiSWi

SEi NWi

SEi

NWi

SWi

NEi Of NEi

John Watson

Nicholas Probeck . H. Mayhew

M. L. Kenyon

D. J. Tew and H. W. Eldrud

D. J. Tew and II. W. Eldrud

D. J. Tew and H. W. Eldrud

Lewis J. Merritt. .

Lewis J. Merritt.

Lewis J. Merritt

Lewis J. Merritt

Lewis J. Merritt.

Emll Hartmann

Emil Hartmann

Emll Hartmann

Emil Hartmann

James II. Baker, Fan- nie A. Griffon and Millie W. Griffen

James H. Baker, Fan' nie A. Griffen and Millie W. Griffen

James H. Baker, Fan- nie A. Griffen and Millie W. Griffen.

James H. Baker, Fan- nie A. Griffen and Millie W. Griffen

James H. Baker, Fan- nie A. Griffen and Millie W. Griffen

James H. Baker, Fan- nie A. Griffen and Millie W. Grltten.

Parts of Sections.

NENE,SiNEi,NWiof SEi

NWi NEi, NW.SWi NWi

Nl SWi and SEi NWi

Lots 1, 2, 3 and 7

Lots 4, 5 and 6 and SWi SWi

Wiof NWi

Wi SEi and SEi of SWi Ei SWi and SWi SWi.

NWi of NWi

swiorswi

Si SWi and SWi SEi.

Niof SEi

SWiNWi

NWi NEi

NEi

NWi

SWi

WiSEi

NEi

NWi

SWi

SEi

SWi

SEi of NWi..

Dec. 15, 1890 Dec 15, 1890 Dec. IB, 1890 Dec. 16, 1890 Dec. 15, 1890 Dec. 15. 1890 Dec. 15, 1890 May 17, 1890 Maj 17, 1890 May 20, 1890 May 20, 1890 May 20, 1890 Jud. 14, 1890 Jun.28,1890 Jud. 26, 1890 Jun. 26, 1890 July 26, 1890

Sep. 1,1890

Sep. 1,1890 Sep. 1,1890 Sep. 11, 1890

Sep. 11, 1890 Oct. 1,1890

Oct. 16, 1890

Oct. 16, 1890

Oct. 18, 1890 Dec-16, 1890 Deal 8, 1890 Dec. 16, 1890 Dec .16, 1890 Dec. 16, 1890 Dec. 26, 1890 Dec. 26, 1890 Dec. 26, 1890 Dec. 26, 1890

Jan. 13, 189:

Jan. 13.

Jan. 13,

Jan. 13, 189

Jan. 13, 189

Jan. 13, is):

Iron Obeb Of Minnesota.

To Whom Leased.

James H. Baker, Fan- nie A. Grlffen and Millie W. Griflen

James II. Baker, Fan- nie A, Griflen and Millie W. Grlffen

James H. Baker, Fan- nie A. Griflen and Millie W. Griflen

James H. Baker, Fan- nie A. Grlffen and Millie W. Griflen

James H. Baker, Fan- nie A. Griflen and Millie W. Griflen

James H. Baker, Fan- nie A. Griflen and Millie W. Griflen.. .

James H. Baker, Fan- nie A. Grlffen and Millie W. Griflen

James H. Baker, Fan- nie A. Griflen and Millie W. Grlffen

James H. Baker, Fan- nie A. Griflen and Millie W. Griflen

James H. Baker, Fan- nie A. Griflen and Millie W. Griflen

James H. Baker, Fan- nie A. Griflen and Millie W. Griflen...

Jarni-s n. Baker Fan ate A. Uriftfn and Millie W Grlffen

Jam is II. Baker Fan- nie A. Griflen and Millie W. Oriffen...

James H. Baker, Fan- nie A. Griflen and Millie W. Griflen

James H. Baker, Fan- nie A. Grlffen and Millie W. Griffon

James H. Baker, Fan- nie A. Griflen and Millie W.GriflVn

Henry G. Inuereon

Henry G. Ingerson. ..

Henry G. Ingerson

Henry G. Ingerson. . .

Parts of Sections.

SWi SWi

Wi SEi.SWiNEiand SE SWi

NWiNEi.WiNWiand SEi NWi

EiSEi

Si SWi and Si SE1 . .

SEi

Si NWi and Ni SWi.

SWi NWi and NWi of SWi

Ni NEi, NEi NWi and Wiof NWi

NWi

9i NWi

EiSEl

Si SEi, Si SWi

Nj SWi, SWi SWi

Wi NEi

Ei SEi and Ei NEi. - .

NEi

NWi

SWi

SEi

Jan. 13, 1891

Jan. 13, 1801 Jan. 13, 1S01 Jan. 13, 1891 Jan. 13, 1891 Jan. 13, 1891

Jan. 13, 1891

Jan. 13, 1891

Jan. 13, 1891

Jan. 13, 1891

Jan. 13, 1891

Jan. 13, 1891

Jan. 13, 1891

Jan. 13, 1891

Jan. 13, 1891 Feb. 9, 1691 Feb. 9,1891 Feb. fi.1891 Feb. 9,1891

Part Vii.

Legislation Relating To Mineral

Lands In Minnesota.

Congress enacted in 1866, 1870 and 1872, an elaborate scheme of regulations for the mineral lands of the Pacific slope and the western interior portions of the United States, but its provisions were made not to apply to the states of Michigan, Wisconsin and Minnesota, which were "declared free and open to exploration and purchase, according to legal sub-divisions, in like manner as before the tenth day of May, 1872. And any bona fide entries of such lands within the states named, since the tenth day of May, 1872, may be patented without reference to any of the foregoing pro- visions of this chapter. Such lands shall be offered for public sale in the same manner, at the same minimum price, and under the same rights of pre-emption as other public lands."*

All the lands of the state, therefore, are subject to the laws that have been enacted for "agricultural lands." When a public sur- vey and sub-division of any township has been made, all its lands are divided into three classes: 1. School lands, comprising sec- tions 16 and 36; 2. Agricultural lands, and 3. Swamp lands. Those lands which are wet and are returned as "swamp lands" by the surveyors, are by law ordered to be patented to the state, and the state may dispose of them as it chooses. In Minnesota large quantities of these lands have been granted to railroad corpora- tions. Special acts of congress have allowed to the state others of the original agricultural lands. Such lands, when patented, be- come "state lands," and are known as University lands, Agricultural College lands, Salt Spring lands, Capitol lands, etc. The remainder of the original agricultural lands, held by the United States are subject to sale, homestead or other disposition, according to the

♦The present laws for the disposition of the mineral lands of the United 8tates are found in chapter 6 of the revised statutes, title: "Mineral Lands and Mining re- sources," and in the regulations of the general land office of date April 1, 1879.

Iron Obes Of Minnesota. 357

laws of the United States. Some of them have been granted to railroads, and in Michigan many in the northern peninsula were patented to the company which built the Sault Ste. Marie canal. Application respecting the lands of the United States within the state of Minnesota should be made to the registers of the various land offices. For the iron regions of Minnesota the register's of- fice is at Duluth.

The State of Minnesota, having come into possession, through the operation of the laws and grants of congress, of lands on which were found to be valuable deposits of iron, and of silver and cop- per, found it necessary, in order to protect its prospective revenue interests in these lands, to enact some regulations for their sale or lease. The legislature of 1889 therefore passed the following:

ACT REGULATING THE SALE AND LEA8E OF MINERAL AND OTHER LANDS BELONGING TO THE STATE.

Sxotion 1. The commissioner of the land office of the State of Minnesota is hereby authorized to execute leasee and contracts for the mining and shipping of iron ore, from any lands now belonging to the state, or from any lands to which the state may hereafter acquire title, subject to the conditions herein- after provided.

Sao. 2. The application for a mineral lease, as herein provided, shall be in such form as the state land commissioner may prescribe. It shall correctly describe the land desired to be leased, and shall consist of contiguous descrip- tions, which, in the aggregate, shall not exceed one hundred and sixty (160) acres in any one lease, unless some of the descriptions shall be fractional sub- divisions, in which case the acreage may exceed the number above mentioned. Before any lease shall be granted, th* applicant shall pay to the state treasurer the sum of twenty-five dollars ($25), and in case two or more personb shall ap- ply for a lease at the same time, then, the one who will pay the largest sum of money therefor, shall be entitled to receive the lease first, provided for in this act

Ifrowided further. That in case any persons, whether as owners, lessees or otherwise, shall have sunk, or shall hereafter sink mining shafts, or make other mineral developments, to the amount of not less than $5,000 in good faith under the presumption that the lands belonged to them, or that they had fall legal right to operate thereon for iron ore or other minerals, which hall be ascertained to be upon lauds belonging to the state or leased under the provisions of this act, such persons shall have a first or prior claim, on the teems above provided, to such development and to a reasonable area of land to embrace and include such improvements.

The holder of a mineral lease, secured as above provided, shall have the right to prospect for iron ore on the lands embraced therein, for a period of one year from the date thereof, at which time said right shall terminate. Provided that no iron ore shall be removed therefrom until a contract, as hereinafter pro- vided, shall have been executed.

Sac. 8. At any time prior to the expiration of said lease, the lease-holder, or any assignee thereof, shall have the right to obtain from the said commis- sioner of the state land office a contract, which shall bind the state of Minne- sota, aa thearty of the first part, and the person, persons or corporation to whom said contract shall issue, as a party of the second part, in a mutual observance of the obligations and conditions as specified therein.

Sno. 4. The contract provided for in section three (3) shall be as follows:

This indenture, made this day of , A. D.t one thousand eight huudred

and , by and between the State of Minnesota, party of the first part, and

, party of the second part, Witnesseth, That the party of the first part

in conaJaeration of the sum of one hundred dollars ($100) to it in hand paid by

358 Bulletin No. Vi.

the party of the second part, being the first annual payment hereinafter pro- vided for, the receipt whereof is hereby acknowledged, and in further consid- eration of the covenants and conditions herein contained, to be kept and performed by the part. . . .of the second part, does hereby contract, lease and demise to the part. . . .of the second part for a term of fifty (50) years from and after the day of. ... , one thousand eight hundred and. . . . , the follow- ing described land situated in the county of . . . . , in the state of Minnesota,

viz: , which premises are leased to the part. ... of the

second part for the purpose of exploring for, mining, taking out and removing therefrom the merchantable shipping iron ore, which is, or which hereafter may be found on, in, or under said land, together with the right to construct all buildings, make all excavations, openings, ditches, drains, railroads, wagon roads and other improvements upon said premises which are or may become necessary or suitable for the mining or removal of iron ore from said premises, with the right, during the existence of this lease, to cut and use the timber found upon said premises for fuel, other than for smelting purposes, and so far also as may be necessary for the construction of buildings required in the oper- ation of any mine or mines, on the premises hereby leased, as also the timber necessary for drains, tramways and supports for such mine or mines. Pro- vided, however, that the part of the second part shall have the right at

any time to terminate this agreement in so far as it requires the part of the second part to mine ore on said land, or to pay a royalty therefor, by giving written notice to the party of the first part, which shall be served by leaving the same with the commissioner of the state land office, who shall officially in writing acknowledge the receipt of said notice, and the foregoing lease shall terminate sixty (60) days thereafter, and all arrearages and sums which may be due under the same up to the time of its termination, as set forth in suck notice, shall be paid upon settlement and adjustment thereof.

The party of the first part further agrees thao the part. . . .of the second part shall have the right under this agreement to contract with others to work such mine or mines, or any part thereof, or to subcontract the same, and the use of said land, or any part thereof for the purpose of mining for iron ore with the same rights and privileges as are herein granted to the said part

of the second part. The part of the second part in consideration of the

premises, hereby covenants and agrees to and with the party of the first part;

that the part of the second part will, on or before the twentieth (20th)

days of April, July, October and January, in each year, during the period here- inbefore stipulated, or during the period this contract continues in force, pay to the treasurer of the state of Minnesota, for all the iron ore mined and removed from said land during the three (3) months preceding the first day of the month in which payment is to be made, as aforesaid, at the rate of 25 cents per ton for all the iron so taken out, mined and carried away, each ton to be reckoned at twenty-two hundred and forty (2240) pounds.

The part of the second part, at the time of such payment,- shall transmit to the commissioner of the state land office an exact and truthful statement of the amount of iron ore removed during the three months for which such pay- ment shall be made. The iron ore so taken by the part of the second part

from said land shall be weighed by the railroad company transporting the same from said land, which weight shall determine the quantity as between the par- ties hereto. Said part of the second part shall furnish the commissioner

of the state land office monthly statements showing the aforesaid weights; the right, however, is hereby conceded to the said party of the first part, by its duly authorized agents, to inspect, review, and test the correctness of said railroad company's scales and weights, at any time and in such manner as may seem proper to adopt, it being understood that any errors in these respects, when ascertained, shall be recognized and corrected. The part of the second pait agrees to pay all taxes, general or specific, upon the laid so leased which may be assessed, either against such land and the improvements thereon, or the iron ore product thereof, or any personal property at said mines, during the continuance of this lease; just the same as though the lands herein leased were owned in fee by the said part. ... of the second part, and at the termina- tion of this lease to quietly and peaceably surrender the possession of said land to the party of the first part.

The part of the second part further covenants that within five (5) years

Ibon Ores Of Minnesota. 359

from the completion of a railroad within one mile of said land there shall be mined and removed therefrom at least one thousand (1,000) tons of iron ore, and that at least five thousand (5,000) tons shall be annually, thereafter, mined and removed therefrom, and in owe the said part — of the second part shall not annually remove from said land the five thousand (5,000) tons of ore as above stipulated, the part. ... of the second part shall pay into the treasury of the state of Minnesota a royalty of 25 cents per ton on 5,000 tons, which pay- ment shall be made quarterly as above specified.

Provided further, that up to the time when the first one thousand (1,000) tons of iron ore is required to be mined and removed, as hereinbefore specified, there shall be annually paid into the treasury of the state of Minnesota, by the

part of the second part, the sum of one hundred dollars ($100.00), which

payment shall be made on or oefore the first day of August of each year.

It is mutually understood and agreed that upon the termination of this agreement, whether by the acts of the parties, or either of them, or by limita- tion, the part of the second part shall have ninety days in which to remove

all engines, tools, machinery, railroad tracks and structures erected or placed

by said part on said land, but shall not remove or impair any supports

placed in the mines, nor any timbers or frame work necessary to the use and maintenance of shafts or other approaches to the mines or tramways within the mines.

The part. ... of the second part shall open, use and work the said mines in such manner only as is usual and customary in the skillful and proper mining operations of similar character when conducted by the proprietors themselves on their own lands, and so as not to do, cause, or permit, any unnecessary or unusual permanent injury to the same, or inconvenience or hindrance in the subsequent operating of the said mine, and in the working of said mine, the part of the second part shall deposit all earth, rook, and other useless material or rubbish at such places and in such manner as will not conflict with or embarrass the future operating of said mines.

The party of the first part expressly reserves to itself (and the part of the

second part assents thereto) the right, by its duly authorized agents, to enter into and upon the above described premises and any part or parts thereof, at any time or times, to inspect and survey the same, and measure the quantity of ores that shall have been mined and removed therefrom, not unnecessarily or unreasonably hindering or interrupting the operations of lessees.

The covenants, terms and conditions of this lease shall run with the land and be in all respects binding and operative upon all sub-leases and guaranty es under the part of the second part.

It is further provided that the present lease is granted upon the express con- dition that if the said royalty, or any part thereof, be and remain unpaid after the days and time herein specified, and if the same remain in default for a period of sixty (60) days, or in case the part of the second part fail to keep and perform any of the covenants or conditions herein expressed to be kept and performed bv slid part. . . *of the second part, then and from thenceforth

and m either of those events, it shall be lawful for the part of the first part,

at its own option, to take possession of the said leased premises with or with- out any previous notice or process whatever, to re-enter, and the same to have and possets again, as fully and completely as though no lease had been given to the said part. . . .of the second part, and they and all parties claiming under them shall be wholly excluded therefrom.

The part. . . .of the first part reserves and shall at all times have, proses? and hold a Hen upon all ore mined, and on all improvements made on said prem- ises by the part. . . . of the second part for any unpaid balances due on this contract.

The part of the first part reserves the right to grant to any person or

corporation the right of way necessary for the construction and operation of one or more railroads over or across the land herein leased, without let or hin- drance from the part. ... of the second part; but such railroad or railroads shall not manifestly or materially interfere with the mining operations carried on. on said premises.

Bao. 6. All payments under this act ehall be made to the state treasurer on the order of the state auditor, and shall be credited to the permanent fund of the class of land to which it properly belongs.

360 Bulletin No. Vi.

Sec. 6. The land commissioner is hereby authorized and empowered, in case the lessee under any lease hereinbefore provided for fails or neglects to fully comply with all the conditions and covenants of such lease, to at once enter upon the premises described in duch lease and take possession of the same, any rule of law or equity to the contrary notwithstanding.

Sec. 7. Should copper or any other valuable mineral be discovered on any land leased as heretofore authorized, the terms and conditions on which the same may be mined shall be agreed upon by the state land commi sioner and lessee, and in case they are unable to agree, then each shall choose a referee — the two persons thus selected shall choose a third. The decision of said board shall be final and binding on the parties in interest.

Sec. 8. The ptate land commissioner is hereby authorized to lease state lands for hay or grass privileges, subject to suck restrictions as he may pre- scribe; provided that no such lease shall be for more than one (1) calendar year.

Sec. 9. Whenever state lands situated in the counties of St. Louis, Lake and Cook are sold, for which contracts or patents are issued, it shall be proper for the land commissioner of the state land office to endorse across the face of such contracts or patents the following words: "All mineral rights reserved to the state." The effect of such endorsement shall be to reserve to the state all mineral rights.

Sec. 10. This act shall take effect and be in force from and after its passage.

On these favorable terms 153 leases* have been issued under sec- tion 2 of the above law, and under section 3 of the same six con- tracts, bringing into the state treasury $4,425. Applications have been made for over 600 leases. About two-thirds of the applica- tions are on the Mesabi range, between the line of the Duluth & Iron Bange railroad and the Duluth and Winnipeg railroad. Leases have been issued upon the Vermilion range as far west as Town 47 of Eange 125, Fifth Meridian. The major portion of these leases have been taken out for the purpose of exploring for iron ore, although it is reported that a few of them have been issued for silver and copper.

The form generally adopted by the fee owner, for giving an in- dividual or company the privilege to explore on their lands is in shape of an option.

The option gives the individual or company the right to go on to the property described and explore or mineral. .There are a great many different forms, but the one almost universally used by the larger land companies allows the explorer to erect suitable camps, use all timber necessary with the exception of pine, hem- lock and cedar, for building and shaft timbering, and to sink test- pits and shafts wherever they desire, requiring them to employ a certain number of men continuously and agreeing to grant to the operating company a lease for a term of years, after a certain amount of ore has been shown up. This lease generally requires the mining company to pay a royalty, ranging from 25 cents to 50 cents per ton, on all ore mined.

The Salt Spring lands of the state, received from the United States on the admission of the State into the Union, were devoted,

♦For list of those leases see paf?e 350.

Iron Ores Of Minnesota. 361

in 1873, to the maintenance of the geological and natural history survey of the state, and are managed and sold by the board of re- gents of the state university.

Summary Of Canadian Mining Regulations.

The following is a summary of the regulations with respect to the manner of recording claimR for mineral lands, other than coal

lands, and the conditions governing the purchase of the same:

Any person may explore vacant Dominion Lands not appropriated or re- served by government for other purposes, and may search therein, either by surface or subterranean prospecting, for mineral deposits, with a view to ob- taining a mining location for the same, bnt no miuing location shall be granted until actual discovery has been made of the vein, lode or deposit of mineral or metal within the limited*of the location of claim.

A location for mining, except for iron or petroleum, shall not be more than 1,500 feet in length, nor more than 600 feet in breadth. A location for mining iron or petroleum shall not exceed 160 acres in area.

On discovering a mineral deposit any person may obtain a mining location, upon marking out his location on the ground, in accordance with the regula- tions in that behalf, and filing with the agent of Dominion lands for the district within sixty days from discovery, an affidavit in form prescribed by mining regulations, and paying at the same time an office fee of five dollars, which will entitle the person so recording his claim to enter into possession of the loca- tion applied for.

At any time before the expiration of five years from the date of recording his claim, the claimant may, upon filing proof with the local agent that he has expended $500 iu actual mining operations on the claim, by paying to the local agent therefor 85 per acre cash and a further sum of $50 to cover the cost of survey, obtain a patent for said claim as provided in the said mining regula- tions.

The Ontario Legislature has made still more liberal laws relat- ing to the acquisition of unsurveyed mineral lands, as may be seen from the following summary of the provisions of the Geneial Act of the Province of Ontario (R. S. O. Cap. 29).

Any person or persons may explore for mines or minerals on any Crown lands, surveyed or unsurveyed, not marked or staked out or occupied.

The price of lands sold as mining locations is two dollars per acre, the pine timber being reserved to the Grown. Patentees or those claiming under them may out and use such trees as may be necessary for buildiug, fencing or fuel, or for any other purpose essential to the working of mines.

Mining locations in ud surveyed territory shall be rectangular in shape, and the bearings of the outlines thereof shall be doe north and south and due east and west astronomically, and such locations shall be one of the following dimen- sions, viz*, eighty chains in length by forty chains in width containing 320 seres, or forty chains square, containing 160 acres, or forty chains in length by twenty chains in width, containing 80 acres.

All such locations must be surveyed by a Provincial Land Surveyor, and be connected with some known point or boundary at the cost of the applicant, who must file with a pi. cation, surveyor's plan, field notes and description of location applied for.

In all patents for mining locations a reservation of five per cent of the acre- age is made for roads.

Lands patented under tbe Mining Act are free from all royalties or duties in respect to any ores or minerals thereon and no reservation or exception of any mineral is made in any patents.

Part Viii.

Glossary Of Mining And Geological

Terms.

[These terms are selected from glossaries published in Volume IX, Tram. Am. Inst. Main. Eng.. by Dr. R. W. Raymond; in Balch's Mines, Miners and Mining Interests of Vie U. 8. and in the Report of the Royal Commission upon the Mineral Resources of Ontario. and other sources. Some terms have been added that have been met with only among the miners of Minnesota.]

Accessory minerals— Minerals found in crystalline rocks in such small proportions that their absence would not alter the lithological name of the rock.

Acid rock— A rock containing 55 per cent, or more of silica as opposed to basic rock in which the alkaline bases predominate.

Adit— A nearly horizontal passage from the surface, by which a mine is entered and drained.

Aerolites— Meteoric masses of metallic or other mineral substances which hare fallen to the earth through the air. The metallic aerolites consist principally of me- tallic iron, nickel and chromium, and the non-metallic of crystalline minerals, and resemble greenstones; others consist of mixtures of these.

Agglomerate— An accumulation of more or less rounded fragments of rock in an old volcanic vent or immediately connected with a volcano, the rounding having been caused by friction in the volcano or in the air, and not by the action of water as in the case of a conglomerate.

Alblte -Soda, feldspar; a silicate of alumina and soda, crystallizes in triolinic system.

Alluvium— Recent aqueous deposits of silt or mud.

Alumina— Oxide of aluminum. Pure crystalline alumina is represented by corundum, sapphire and ruby. The commonest form of alumina is as a silicate, of which clays are mostly composed, and as the compound silicates of aluminum and other metals, of which a very large class of minerals is formed

Amalgam— A combination of mercury with another metal, especially gold or silver.

Amalgamation— The process of uniting mercury with gold, silver, etc.

American forge—See Catalan forge.

Anurrphous— Without form; applied to rocks and minerals having no definite structure.

Amphiboltte— See Hornblende.

Amygdaloid— An igneous rock containing almond-shaped kernels of minerals such as quartz or agate, calcspar, etc., which have resulted from the filling up of ves- icular cavities that originally existed in these rocks due to the expansion of jrases in them while still hot and in a soft condition.

A northite— Lime-feldspar; a silicate of alumina and lime; crystallization triclink*.

Anthracite— See Coal.

Anticlinal— The liste of a crest, above or under ground, on the two sides of which the strata dip in opposite directions. The converse of synclinal.

Apatite— Mineral phosphate of lime. It is usually of various shades of green and bluish green, brownish red and light gray. It occurs in grains and small crystals in nearly all trappean rocks, in granites, gneiss, etc. It represents the fifth cle-

free in the hardness of minerals, n the U. S. Revenue Statutes, the end or edge of a vein nearest the surface. Aqueous.— See Sedimentary. Arch—1. A portion of a lode left standing when the rest is extracted, to support the

hanging wall, or because it is too lean for profitable extraction.

2. The roof of a roverberatory furnace. Archaean— A term proposed by Dana and largely adopted for the Azoic period or age.

or what had formerly been called the primitive rocks, the lowest of the five

grand divisions or periods of geological time. It embraces the Laurentian and

Keewatin formations, (the Huronian also, according to some geologists), all of

which rocks are sometimes called the pre-Cambrian. See Azoic, Laurentian and

Huronian. Arenaceous— Sandy rocks composed of sand or containing sand along with other in-

irredients Argentiferous— Containing silver. Argentine— Sulphide of silver; contains 86H per cent of silver and 13& of sulphur; heavy

blackish gray in color, malleable, easily cut by a knife; it is an important ore

of silver, common in the Thunder Bay silver region. Argillaceous— Containing clay, either soft or hardened, as in shale, slate, argillyte, etc. Arm— The inclined member or leg of a set or frame of timber. Artesian Wells— Deep wells bored through the solid strata. In properly selected

situations the water generally rises in them to the surface, or flows over.

Iron Ores Of Minnesota. 363

fibrous, flexible variety of hornblende. Chrysotile, a fibrous variety of serpentine is also called asbestos. It fuses at a lower temperature, but for steam-packing answers ibe same purpose.

Attcoision-theory— The theory that the matter filling fissure veins was introduced in solution from below.

Assay— To test ores and minerals by chemical or blow pipe examination; said to be in the dry way when done by means of heat (as in a crucible), and in the wet or humid way when by means of solution and precipitation or liquid tests. An assay differs from a complete analysis in being confined to the determination of certan ingredients, the rest not being determined. Bot h assays and analyses may be either qualitative or quantitative; that Is, they may determine the presence merely, or also the amount of some or all of the constituents of the substance examined.

A tUe— Refuse rock.

Auget or Auaette— A priming tube, used in blasting.

Auriferous— Containing gold.

Azoic— Without life. Applied to all the ancient crystalline rocks, because they show no evidence of the existence of life on the earth at the time of their formation.

Bode— With reference to an adit, drift or stope, the part of the ore deposit between it and the next working above, or the surface. 2 See Face.

Back-shifts- The second set of miners working in any spot each day.

Back-skin— A leather covering worn by men in wet working.

Bait— A pitman's provisions.

Bailing- -The aggregation of iron in the puddling or blowing process into Itall* or Iouim.

Batik— An ore-deposit worked by surface excavations or drifts above water-level.

Bar—1. A drilling or tamping rod. 2. A vein or dyke crossing a lode.

Barney— A small car attached to a cable, used to null cars up a slope or inclined plane.

Barn— A piece of small pipe inserted in the end of a cartridge to carry the squib to the powder.

Barrier-pillars- Pillars of ore, larger than usual, left at intervals to prevent too exten- sive crushing when the ground comes to be robtxd.

Barrow— 1. A heap of attic or rubbish; a dump. 2. A vehicle in which ore, rock, etc., are wheeled.

Barytes— Sulphate of barium; also called heavy spar, from its high specific gravity. When finely ground it is used as a substitute for white lead paint. It occurs as a veinstone and is abundant iu some of the veins between Thunder bay and Pigeon point .

Basalts- Igneous rock having a columnar structure like that of the Giants' Causeway in Ireland. LIthologlcally, basalt is closely allied to diabase.

Base Metals— The metals not classed as noble or precious.

Basic— h. In furnace practice, a slag In which the earthy bases are in excess of the amount required to form a neutral slatr with the silica present. 2. In geology, a rock which contains less than 55 per cent of silica.

Basic-lining process— An improvement of the Bessemer process, in which by the use of a basic lining in the converter and by the addition of basic materials during the blow, It Is possible to eliminate phosphorus from the pig-iron, and keep it out of the steel.

Basin— L A natural depression of strata containing a coal bed or other stratified de- posit. 2. The doposit itself.

Basque— A lining for crucibles or furnaces; generally a compound of clap, etc.. with charcoal dust

Basset—" An outcrop;" the edge of a stratum.

Bath— A mass of molten material in a furnace, or of a solution in a tank.

Battery— tl A bulk-head of timber."

Beating—Bee Strike.

Bed— A layer of rock or mineral later in origin than the one below, and older than the one above; a regular member of the doposit and not an intrusion.

Bedded-vcin or Bed Vein — A lode occupying the position of a bed, that is, parallel with the stratification, of the enclosing rock.

B$d-rock— The solid rock underlying alluvial and other surface formations.

Bed-way— An appearance of stratification or parallel marking in granite.

Beits aephtmphtrrizttig process—The removal of phosphorus from molten pig-iron in n puddling furnace, lined with iron oxide and filled with a mechanical rabble agitate the bath. Red-hot iron ore is added. See Krupp's HHishlnu process.

Belt—A term used in the description of the geographic distribution of strata, especial- ly if Inclined strata, to indicate a zone or bank of a particular kind as exposed on the surface.

iron-' Pig-iron suitable for the Bessemer process.

ore— Iron ore suitable for making steel by the process. See pane 187 for full definition.

Process— The process of decarburizlng a hath of molten cast iron by blowing air through It, in a vessel called a converter,

tool ending below in a conical cavity, for recovering broken rods from a l>orc- hole.

BUlst— 1. Iron or steel drawn from a pile, bloom or ingot into a sinjill bar for further manufacture. 2. A small bloom.

Bing-ore— Ore in lumps.

-fuAe—A hole or slumt through which ore is thrown.

Utt— The cutting end of a boring implement.

Bitumen— Mineral pitch; It iscotni>osed of carbon and hydrogen.

Bituminous— Containing disseminated bitumen or its elements, which may generally be distinguished by the dark color or the odor.

BUtertpar— Also called Pearls par. The crystalline form of carbonate of lime and mag- nesia; the pure form of dolomite. It consists of one part or equivalent of car- bonate of lime and one of cart>onate of magnesia.

364 Bulletin No. Vi.

Black-band— An earthly carbonate of iron, accompanying coal-beda. Worked in Great Britain. Ohio and Pennsylvania.

Black-damp— Carbonic acid gas.

Black-jack— Dark varieties of zinc blende or sulphide of zinc. It has a resinous lustre and yields a light colored streak or powder.

Black-lead— Graphite

Black sand—Henvy particles of black oxides of iron, sometimes accompanied by allu- vial gold.

Blast— l The operation of blasting, or rending rock or earth by means of explo- sives. 2 The air forced into a furnace to accelerate combustion. 3 The period during which a blast furnace is in blast, that is in operation.

Blast furnace— A furnace, usually a shaft-furnace, into which air is forced under pressure.

Blasting-stick— A simple form of fuse.

Blende— Without any qualification means zinc blende or the sulphide of sine which has the lustre and often the color of common resin, and yields a white streak and powder. The darker varieties are called black-jack by the English miners. Other minerals having this lustre are also called blendes, as antimony-blende, ruby-blende, pitch-blende, hornblende.

Blind level— I. A level not yet connected with other workings. 2. A level for drain- age, having a shaft at either end, and acting as an inverted siphon.

Blind-shaft— See Winze.

Bloat— A hammer swelled at the eye.

Blood-stone— A dark green variety of chert or jasper with small red spots.

Bloom— 1. A large steel bar, drawn from an ingot for further manufacture. 2. A rough bar of iron, drawn from a Catalan or bloomary ball, for further manu- facture. See BUM.

Bloomary- A forge for making wrought-iron, usually directly from the ore. The sides are iron-plates, the hair-plate, at the back, the cinder-plate at the front, the tuyere-plate, through which the tuyere passes, at one side (its upper part being called in some bloom ar lea the merritr-pUtie,) the fore. spar-plate opposite the tuyere-plate, its upper part being the skew-plate, and the boUom-plaU at the bottom.

Blossom— The oxidized or decomposed outcrop of an ore deposit or coal-bed. Also called smut and tailing. See Oossan.

Blow— A single heat or operation of the Bessemer converter.

Blower— 1. A strong discharge of gas from a fissure. 2. A fan or other apparatus for forcing air into a furnace or mine.

Blow-in— To put a blast furnace in operation.

Blow-out— I. To put a blast furnace out of blast, by ceasing to charge fresh materials, and continuing the blast until the contents of the furnace have been smelted. 2. A large outcrop, beneath which the lode contracts is called a blow-out. 3. A shot or blast is said to bo a blow-out when it goes off like a gun and does not shatter the rock

Bog iron ore— A loose, earthy brown hematite, of recent origin, formed in swampy ground.

Bonnet— A covering over a cage to shield it from objects falling down the shaft.

Boot— A leather or tin joint connecting the blast-main with the tuyere or nozzle in a bloomary.

Board-and-piltar . See Post-and-staU.

Borer. See Drill.

Burt— Opaque black diamond.

Bosh— 1. A trough in which bloomary tools are cooled. 2. (Or Boshes.) The portion of a shaft furnace in which it widens from above the hearth up to its maximum diameter.

Bottomcr— The man stationed at the bottom of a shaft in charge of the proper loading of cages, signals for hoisting, etc.

Boulder or Bowlder— A fragment of rock brought by moving water or ice from a dis- tance, usually rounded by attrition. .

Bowke—A small wooden box in which iron ore is hauled under ground.

Box-biU— A tool used in deep boring for slipping over and recovering broken rods.

Box-timbering. See Plank-Umbering.

Brace— The platform, collar or landing at the mouth of a shaft.

Brace-head— A cross-attachment at the top of the column of rods in a deep boring, by means of which the rods and bit are turned after each drop.

Brakesman— The man in charge of a hoisting engine.

Branch— A small vein or elbow departing from the main lode, and in some cases returning.

Brasses - Pyrites.

Brattice— A plank lining, or a longitudinal partition of wood, brick, or even cloth, in a shaft, level or gangway, generally to aid ventilation.

Brazil— Iron pyrites.

Breast— 1. The face of a working. 2. The chamber driven upwards from the gangway, on the ore deposit, between pillars left standing. 3. That side of the hearth of a shaft furnace which contains the metal-notch.

Breast-boards— Planking placed between the last set of timbers and the face of a gang- way or heading which is quicksand or loose ground.

Breccia— A conglomerate in which the fragments are angular.

Bridlc-cliains— Safety-chains to support a cage if the link between the cage and rope should break.

Brob—A peouliar spike, driven alongside the end of an abutting timber to prevent Its slipping.

Browse— Ore imperfectly smelted, mixed with cinder and clay.

Bucker—A flat piece of iron with a wooden handle used for breaking ore.

Iron Ores Of Minnesota. 365

BueMng—8ee Cobbing. The bucking-hammer or bucking-iron is a broad-headed hammer used for bucking or breaking ore; the ore is broken on a flat pieoe of iron called the bucking-plate. Buckshot cinder— Cinder from the iron blast furnace, containing grains of iron. Buddie— A circular tub, pit or enclosure for separating finely divided ores from the

waste by means of water. Bulkhead— A tight partition or stopping in a mine for protection against water, fire or

gas. Bulldog— A refractory material used as a furnace-lining, obtained by calcining mill-

ctnder, and containing silica and ferric oxide. Bullfrog— See Barney.

Bullrpump—A direct single-acting pump, the steam cylinder of which is placed over the top of a shaft or slope, and the piston-rod attached to the pump-rods. The steam lifts piston and pum-rods, and their own weight produces a down-stroke. Bull wheel- A wheel on which is wound the hoisting cable.

Bully— A pattern of miner's hammer, varying from "broadJ>ully" to "narrow-bully:' Bunch— in mining, an irregular mass of ore of considerable size. Bunding— A staging of boards on stuUs or sUmpU*, to carry deads. Burden—The proportion of ore and flux to fuel in the charge of a blast-furnaoe. Burnt iron—1. Iron which by long exposure to heat has suffered a change of structure and become brittle. It can be restored by careful forging at welding heat. 2d. In the Bessemer and open-hearth processes, iron which lias boen exposed to oxi- dation until all its carbon is gone, and oxide of iron has been formed in the mass. Burr— Solid rook.

Butt— A surface exposed at right angles to the face. See End. Butty— A miner by contract at so much per ton of ore.

CaoZHtao— Breaking up pieces of flat iron to be piled or fagoted, heated and rolled. Cache— The place where provisions, ammunition, etc.. are cached or hidden by trappers

or prospectors in unsettled regions. Cage—1. A frame with one or more platforms for cars, used in hoisting in a vertical shaft. It is steadied by guides on the sides of the shaft. 2. The barrel or drum in a whim on which the rope is wound. CafmoxoicSee Tertiary. Calamine— The natural carbonate of zinc: one of its most easily reduced ores; occurs

both in beds and veins, mostly in the Carboniferous and higher rocks. Calcareous— Containing carbonate of lime as calcareous sandstone, or composed of it,

as calcareous spar or calcspar. Calcareous tufa— A spongy, porous or vesicular deposit of carbonate of lime from water. It often incrusts vegetable and animal substances, which are thus Raid to be petrified. When the carbonate of lime, is deposited in a more solid form It is called travertine or calo sinter. Stalactites and stalagmites are of this nature. Caleiferous— Carrying carbonate of lime. Calcine— To expose to heat, with or without oxidation; to roast, applied to ores for the

removal of water and sulphur and carbonic acid, etc. ale-spar— See Calcareous.

Cam— A projection from a revolving shaft for raising the stamp by catohing the lower surface of the tappit or collar surrounding the rod on which the stamp-head is hung. The upper side of the cam has an easy curve, such as a parabola, so that when it strikes the tappit it may not jar it when the lifting movement begins. Cam-shaft— A strong horizontal revolving shaft to which a number of cams art) attached In such a manner that no two of them shall strike the tappits at the same Instant, thus distributing the weight to be lifted. Cambrian— Derived from Cambria, the ancient name of Wales. The name given by the late professor Sedgwick of the University of Cambridge to the rocks of the second fauna, tho Llandeilo-Bala group. His "Lower Cambrian" embraced the tone of theTaconlcof America and the primordial of Barrande. Canon—A ravine or gorge, usually on a large scale. Cop, or Cap rock— Barren vein-matter or rock, or a pinch in a lode, supposod to overlie

ore. Captain— The official In immediate charge of the work in a mine. CaroorKrarntt— Containing a carbonate or carbon not oxidized.

Carboniferous System— The system of rocks which succeeds the Devonian or "Old Red Sandstone** and precedes the Permian or New Red Sandstone. It is character- ised by its containing workable seams of true coal. Cornelian— One of the varieties of chalcedony, originally only the red, but now of any

color. Case harden— To convert iron superficially into steel by partial cementation. Caring— A partition or brattice, made of casing-plank, in a shaft.

Carting— Pouring or drawing fused metal from a blast furnace, cupola, crucible, con- verter, or ladle into moulds. Catalan /3W--A forge with a tuyere for reducing iron ore, with charcoal, to a loup of

wrought Iron; aW/wmian/. See Champlaln forge. Cat-toad— 1. A small capstan. 2. A broad-bully hammer. See Bully.. Caving— The falling in of the sides or top of an excavation.

CvlssHM or celcstitt— Sulphate of strontium, a mineral which resembles bar lie in its high specific gravity and is often mistakeu for it. It may be used for many of the same purposes in the arts. — flt-The calcareous, siliceous, ferruginous, etc., matter, cementing together gravel,

broken fragments of rock. etc. Geraattte— Natural carbonate of lead, which sometimes occurs in economic quantities. Chaferu—A forge fire for reheating- ' CwUmonu Translucent varieties of quartz, such as carnelian. agato, siliceous sinter, etc.

366 Bulletin No. Vi.

Chalk— Originally and properly the soft amorphous variety of limestone of the Creta- ceous system used for marking, but now also applied to other subs tanoes, as red chalk or clayey oxide of iron, French chalk or steatite or soapstone.

Chalybeate— Impregnated with Iron (applied to waters)

Chomplain forge or American forge-- A. forge for the direct production of wrought iron.

Senerally used In the United States instead of the Catalan forge, from which it iffers in using only finely-crushed ore and In working continuously.

Changing-housc—A room where miners change and dry their underground clothing. See Dry.

Charge— 1. The materials Introduced at one time or one round into a furnace. 2. The amount of explosive used for one blast.

Cheeks— 1. The sides or walls of a vein or lode. 2. Extensions of the sides of the eye of a hammer or pick.

Chenot process— The process of making iron-sponge from ore mixed with coal-dust, and heated in vertical cylindrical retorts.

Chert— A brittle nearly opaque variety of flint. It generally occurs as nodules or thin irregular beds in limestones, and is abundant at the base of the Animike.

Chill— An iron mould or portion of a mould, serving to cool rapidly and so to harden, the surface of molten Iron which comes in contact wlta It Iron which can be thus hardened to a considerable extent Is chilling iron, and is specially used for cast-iron railway car-wheels requiring hardness at the rim without loss of strength in the wheel.

Chimney— An ore-shoot. See Chute.

Chlorite— A soft, dark green mineral, entering largely Into the composition of chlorltic schist. It is a silicate of alumina, magnesia and Iron, and has a peculiar earthy odor when freshly broken and breathed upon.

Choke-damp— Carbonic acid gas.

Chrome ore— Chromic Iron (chromtte, oxide of chromium and oxldeof iron.)

Chute -(Sometimes written shoot.) 1. A channel or shaft underground, or an inolined trough above ground, through which the ore fails or slides from a higher to a lower level. 2. A body of ore, usually of elongated form, extending down- ward.

Cinder— Slag, particularly from iron blast furnaces.

Cinderpig-SeePLg iron.

Cinder tap. Cinder notch— The hole through which cinder Is tapped from a furnace.

Cinnabar— Sulphide of mercury. A very heavy, red, granular crystalline mineral, giving a bright red streak, and easily reduced to metallic mercury.

Claim— The portions of mining ground held under the Federal or State laws by one claimant or association, by virtue of one location and record.

ClaHtic— Broken, f ragmen tal; a rock composed of pieces, or of fine grains whioh have been formed by the breaking down of pre-existing rooks, as opposed to crystal- line and other rocks which have been formed from the cooling of molten mat- ter, or from the alteration of sedimentary rocks to such an extent that all traces of an original fragmentary origin are obliterated.

Clau-Ironstone—Ol&yey carbonate of iron. A heavy compactor fine-grained clayey looking stone, occurring in nodules and uneven beds among Carboniferous and other rocks. It con talus only 20 to 30 per cent, of metal, and yet much of the iron produced in Great Britain Is made from it.

Cleavage— The property in a mineral of splitting more easily and perfectly in some directions than in others. The cleavage of rock-masses is more properly a joint- ing, unless it follows the planes of bedding.

Clinometer— A simple apparatus for measuring by means of a pendulum or spirit- level and circular scale, vertical angles, particularly dips.

Coal, Anthracite— Hard, black, composed almost wholly of carbon; bituminous or cokinu coaly brownish or black, containing hydro-carbons: and lignite or brown coal, containing much water.

Cobbing— Breaking ore to sort out its better portions. See Spael.

Cleaning Up— The process of collecting together the metal or ore which has accumu- lated In the various contrivances for saving it by mining machinery.

Cobble— An Imperfectly puddled ball, which goes to pieces In the squeezer.

Cobble stones— Smooth, flattened, rounded or elongated stones, larger than pebbles and smaller than boulders; used for paving.

Coffer or Cofer—A rectangular plank frame, used in timbering levels.

Coffin— 1. An old open working. 2. The mode of open working by casting up ore and waste from one platform to another, and so to the suface.

Cog— To roll or bloom Ingots.

Coil Drag— A tool to pick up pebbles, bits of iron, etc., from the bottom of a drill hole.

Coke -When the bitumen is driven out of coal by heating it out of can tact with the air. as In ovens constructed for the purpose, the residue is called coke.

Cold blast— Air forced into a furnace without being previously heated.

Cold short— Brittle when cold. Applied chiefly to iron and steel containing an excess of phosphorus.

Collar— The collar of a shaft is the horizontal timbering around the mouth.

Color— M in ute particles of gold obtained by panning, and too small for their value to

; be estimated.

Combined Carbon— That portion of the carbon in iron or steel which is not visible as

i — i graphite, and Is supposed to be alloyed or chemically combined with the iron.

Complex— In mineralogy, containing many ingredients, compound or composite.

. Some United States geologists use the word as a noun to indicate a complex set

of rocks folded together, or Intricately mixed, involved, complicated or en- "" larged.

Concentration—The removal by meohanloal means of the lighter and less valuable por- tions of ore.

Conchoidal— Shell-shaped. The more compact rooks, such as flint, argillyte, felsyte. etc., break with concave and convex surfaces and are therefore said to have a conchoidal fracture.

Iron Ores Of Minnesota. 367

Concretionary— Tending to grow together. Particles of like chemical composition, when free to move, come together and form nodules of various sizes and shapes which are called concretions. Clay and ironstone nodules, balls of iron pyrites, turtle stones, etc., are good examples. Some greenstones exhibit con- cretionary structure.

Conformable- When beds or strata lie upon one another in unbroken and parallel order they are said to be conformable, and this arrangement shows that no dis- turbance or denudation has taken place at the locality while their deposition was going on. But if one set of beds rests upon the eroded or up-turned edges of another, showing a change of conditions or a break between the formations of the two sets of rocks, they are said to be unconformable.

Conglomerate— A rook consisting of fragments of other rocks (usually rounded) ce- mented together.

Contact— The plane between two adjacent bodies of dissimilar rock. A contact-vein is a vein, and a contact-bed is a bed, lying, the former more or less closely, the latter absolutely, along a contact.

Contemporaneous— Existing together or at the same time.

Contorted— Bent or twisted together. Used where strata are very much folded or crumpled on a considerable scale. If on a small scale they are said to be corru- ffated.

iJoniraelkm— Shrinking. Bocks in passing from a vitreous to a crystalline texture shrink considerably, which may account for the subsidence of certain areas. The whole globe of the earth has shrunk by cooling. This contraction is sup- posed to be a cause of volcanic action.

Converter- See Bememer process.

Cornish Pump— A pump operated by rods attached to the beam of a single-acting con- densing steam-engine. The steam, pressing down the piston in the vertical steam-cylinder, lifts the pump-rods, and these subsequently descend by their own weight.

Corrugated— When beds on a small scale are much wrinKled, folded or crumpled, they are said to be corrugated. On a larger scale they are said to be contorted.

Costeaning or Gosteentnp— Discovering ore-deposits by pits and open cuts, run on the surface transversely to the supposed strike of the ore.

Country or Country-rock— -The rook traversed by or adjacent to an ore deposit.

Courwe— See Strike.

Coursing— Conducting the air-current of a mine in different directions by means of doors and stoppings.

CoutcMching— The name applied by A. C. Law son to the crystalline schists at Rainy Lake. The Vermilion schists of the Minnesota report.

Cramp— A pillar of rook or mineral left for support.

Creep— A rising of the floor of a gangway, occasioned by the weight of incumbent strata, in pillar workings. Also any slow movement of mining ground.

Cretaceous System— The system of rocks next above the Jurassic, so called from .the abundance of chalk which it contains In England. In America the same sys- tem as recognized by Its fossils holds but little chalk.

Crflib (nfl— Close timbering, as the lining of a shaft, or the construction of cribs of tim- ber or timber, earth and rock to support a roof.

Crop— The basset or outcrop of strata at the surface.

-course - A vein crossing the general course of a more important one.

Cmm-eut—A level driven across the course of a vein, or in general, across the direction of thn main workings, to connect two parallel gangways.

Crow or Crow-foot— A tool with a side-claw, for grasping and recovering broken rods in In deep bore-holes.

Crushing md— The same as stamp mill.

Crusher— A machine for crushing ores.

Cryolite— A soft white translucent mineral which melts in ordinary flame. It consists of fluoride of sodium and aluminum, and is valuable for the manufacture of carbonate of soda, and metallic aluminum. It occurs in veins in gneiss in western Greenland.

Crydais— The various geometric forms assumod by nearly all the solid chemical ele- ments and definite compounds, whether natural or formed artificially. The countless modifications of crystalline forms are all grouped under six systems.

CYvdtffline roefca— Consisting of crystalline particles or grains; when the latter arc dis- tinct the rock is said to bo crystalline-granular.

Crystallography— The description or science of crystals.

Cup-andrCone -A machine for charging a shaft-furnace, consisting of an Iron hopper with a large central opening, which Is closed by a cone or ttell pushed up Into it from below. In the annular space around this cone, the ore, fuel, etc., are placed: then the cone is lowered to drop the materials Into the furnace, after which It is again raised to close the hole.

Cupola— A shaft-furnace with a blast, for remolting metals, preparatory to casting.

Cupriferous— Copper-bearing. The Niplgon or Keweenawan formation.

Curb— A timber frame, circular or square, wedged in a shaft to make a foundation for walling or tubing, or to support, with or without other timbering, the walls of the shaft.

Oam— The wall of refractory material, forming the front of the fore-hearth of a blast furnace. It Is built on the inside of a supporting Iron plate (dam-plate). Iron Is tapped through a hole In the dam. and cinder through a notch in the top of the dam.

Damp— Miners in England call gases "damps"; carbonic acid gas Is choke-damp, and light carburotted hydrogen is fire-damp.

Dam-plate— Tike plate upon the dam-stone or front stone of the Ixrttom of a blast fur- nace.

large sheet, placed as a curtain or partition across a gate-road to stop and turn an air-current.

368 Bulletin No. Vi.

Dead— 1. Unventilated. 2. As a vein or piece of ground, unproductive.

Dead ground— Bock in a mine which, although producing no ore, requires to be removed in order to get at productive ground.

Deads— The waste rook, packed in excavations from which ore has been extracted.

Dead voork— Work that is not directly productive, though it may be necessary for ex- ploration or future production.

Deal— Plank used In shaft and gallery timbering.

Decomposition— The breaking up or decay of compounds into simpler chemical forms.

DecrepUatio'*r-The breaking up with a crackling noise of mineral substances when exposed to heat, as when common salt is thrown upon the fire.

Denudation— The washing down of surface deposits so as to lay bare underlying form- ations. This washing away in one place is associated with the idea of deposi- tion in another.

Deposit— Anything laid down. Formerly applied to matter left by the agency of water, but now made to Include also mineral matter in any form, and precipi- tated by chemical or other agencies, as the ores, etc., in veins.

Derrick— A hoisting tower or stand.

Descension-theory— The theory that the material in veins entered from above.

Detritus— Accumulations derived from the wearing down of rock surfaces.

Devitrification— The change from a glassy to a crystalline state.

Devonian system— The geological system of rooks above the Silurian and below the Carboniferous; so-called from Devonshire. In Scotland it was called the Old Bed Sandstone.

Diabase— A dark green, greyish green or nearly black igneous rook, one of the green- stones; consisting of a triclinic feldspar, augite (or pyroxene) and usually some olivine, with magnetic or titan if erous iron, apatite and viridite as accessory minerals. It occurs in dykes, beds, overflows and erupted sheets and masses, and it may be coarsely or very finely crystalline. It is common in all the above forms around lake Superior and north of lake Huron. Diabase differs from basalt in having undergone certain internal mlneraloglcal changes, without, however, affecting its general chemical composition, which is the same in both. Some varieties of amygdaloid have the composition of diabase.

Diagonal stratification— Also called false bedding and current bedding. Many sands and sandstones are marked by lines of subordinate stratification running through the main beds at various angles to their planes; these are due to cur- rents at the time of deposition, and they have received the above names.

Dial— To dial a mine Is to make a survey of it.

Diallage—A very cleavable variety of augite or pyroxene. Gabbro or diallage rock is composed of this mineral and a triclinic feldspar.

Diamond-driU—A form of rock-drill in which the work is done by abrasion Instead of percussion; black diamonds (hortst being set in the head of the boring tool.

Diggings— Applicable to all mineral deposits and mining camps.

Dike or Dyke— A vein of igneous rock.

Diluvium— Sand, gravel, clay, etc., in superficial deposits. See drift.

Dioryte—A crystalline igneous or metamorphic rock, outwardly resembling diabase, and also called greenstone, but composed of a triclinic feldspar and hornblende, generally with some magnetite and apatite as accessory minerals. Dioryte occurs in the same manner as diabase, and is a common rock north of the great lakes. There are several varieties of dioryte, the principal of which are quartz- dioryte, containing free quartz, mloa-dioryte, containing black mica, often abundantly, dioryte-porphyryor por phy ritlc dioryte, in which some of the feld- spar or hornblende is In the form of large crystals among the smaller ones. Both dioryte and diabase sometimes assume a coarsely concretionary structure.

Dip— The inclination of a vein or stratum below the horizontal. The dip at any point is necessarily at right angles with the local strike, and its inclination is steeper than that of any other line drawn in the plane of the vein or stratum through that point.

Disintegration— The breaking asunder and crumbling away of a rook, due to the action of moisture, heat, frost, air and the Internal chemical reaction of the com- ponent parts of rocks when acted upon by these surface Influences.

Dislocatitm— A shifting of the relative posltiou of the rock on either side of a crack or break. It may be up, down or to one side. Equivalent to slip, slide, fault, throw, heave, upthrow, downthrow.

Divining-rod or Dowsing-rod— A rod, most frequently of witch-hazel, and forked in shape, used, according to the old but still extant superstition, for discovering mineral veins, springs of water, oil-wells, etc.

Divisional planes— Planes which divide rocks into separate masses, large or small, in the same way as joints, fissures and backs.

Doleryte—A crystalline igneous rock having the composition of basalt and diabase, but formerly supposed to belong to newer rocks. This distinction has not been maintained. The term is now used to distinguish the coarser grained varieties of basalt In which the component minerals may be distinguished by the naked eye

Dolomyte—A rock consisting of carbonate of lime and carbonate of magnesia in the proportions of one chemical equivalent of each, also called magneslan lime- stone. It occurs in a great many crystalline and non-crystalline forms, the same as pure limestone, and among rocks of all geological ages. When calcined It answers for most of the purposes of ordinary lime. But In the caustic form it would be unfit for putting upon land as a manure. When the carbonate of magnesia is not present in the above proportion the rock may still be called u magnesian limestone, but not a dolomy to, strictly speaking.

Dope— See Explosives.

Downcast— The opening through which the ventilating air-current descends into a mine.

Iron Ores Of Minnesota. 369

Downcome—The pipe through which tunnel-head gases from iron blast-furnaces are

brought down to the hot-blast stoves and boilers, when these are below the

tunnel-head. Drug-twist— A spiral hook at the end of a rod, for cleaning bore- holes. Dressing— The picking and sorting of ores, and washing, preparatory to reduction. Drift— 1. A horizontal passage underground. A drift follows the vein as distinguished

from a cross-cut, which intersects it, or a level or gallery which may do either.

2. Unstratified diluvium, including the till. DrQI—A metallic tool for boring in hard material. The ordinary miner's drill is a bar

of steel, with a chisel-shaped end. and is struck with a hammer. Driving— Ex tending excavations horizontally. Distinguished from sinking and raising. Drum— That part of the winding machine on which the rope or chain is coiled, crystallized crust lining the sides of a cavity. changing-house.

-1. To unload a vehicle by tilting or otherwise, without handling or shoveling

out its contents. 2. A pile of ore or rook. Dune— A heap of blown or drifted sand.

Dust&ate—A vertical Iron plate, supporting the slag-runner of an iron blast furnace. Dyke, see Dike.

Earth's Crust— The external part of the earth, accessible to geological investigation. The use of this term does not necessarily imply that the rest of the earth is not also solid.

Economic Minerals— Any minerals having a commercial value.

Ehoan—K granite vein or belt running through schistose rooks.

AJmerw— Properly a variety of corundum from Cape Emeri in the island of Noxos, but generally used to signify the powder of corundum, a mineral consisting of alumina alone, and ranking next the diamond in hardness.

Engine Shaft— Usually the principal shaft in a mine, and the one at which the hoisting and pumping are done.

Entry— An Adit.

Eocene— The oldest division of the Tertiary system. This name was introduced by Sir Charles Lyell, and means the dawn of the recent.

Eptdotc—A bard mineral, usually of a grass-green or a yellowish green color, common among gneisses, greenstones and certain schists.

Epidosyte— An intimate mixture of epidote and quartz, forming an exceedingly tough and hard rock.

Equivalent— Used in geology in regard to rocks of corresponding age in regions far from each other.

Erosion— The gnawing or wearing away of rocks by means of denuding agencies. The disintegrating processes already referred to soften the rocks, which are then removed by the erosive action of ice or water aided by gravitation, etc.

Erratic— A name often given to transported boulders.

Eruption— A violent breaking forth to the surface of pent-up matters, such as lava, volcanic ashes, stones, mud, water, etc.

Escarpment— A perpendicular cliff, especially of stratified rock.

Exfoliate— To fall off in leaves or scales, as some rocks do by weathering. In this way the ooncretionary structure of some kinds of greenstones is well brought out. the weathered surface showing only rounded masses with the successive layers falling off.

Exploder— A oap or fulminating cartridge placed in a charge of gunpowder or other ex- plosive, and exploded by electricity or by a fuse.

Exploitation— The productive working of amine, as distinguished from exploration.

Explosives— The principal explosives used in mining are gunpowder, a compound of sul- phur, charcoal and potassium nitrate or sodium nitrate; nitro-glyceritie, a liquid compound of carbon, hydrogen, nitrogen and oxygen, produced by the action of nitric acid upon glycerine; dynamite No. 1 or giant-powder, a mixture of nitro- glycerine with a dry, pulverized mineral or vegetable absorbent or dope (com- monly siliceous or infusorial earth); dynamite No. 2, nitro-glyceriue mixed with sawdust, saltpeter, coal-dust, paraffin, etc., in lieu of an explosive dope; litho- fracteur, nltro-glycerine mixed with siliceous earth, charcoal. sodium (and sometimes barium) nitrate and sulphur; diudin. nltro-glycerine mixed with po- tassium nitrate and fine saw-dust: rend-rock. Atlas, Hercules, Umitc, vigoritr*. with other powders, resembling dynamite No. 2. i. e. consisting of nltro-elycor- Ine with a more or less explosive iU>pc; and rn fro- powder, a No. 1 dynamite. In whloh the dope is scales of fine mica. The chlorate, picratr. and fulminate explo- sives are not used in mining, except the fulminate of mercury, which is em- ployed for the caps or exploders, by means of which charges of gunpowder, dyna- mite, etc., are fired,

. The top of a shaft. 2. The opening at the end of a tuyere, opposite the nozzle. 8. The hole In a pick or hammer-head which receives the handle.

any adit, tunnel or stope, the end at which work is progressing or was last done. Fatiband—A zone or stratum in crystalline rock impregnated with metallic sulphides. k revolving machine, to blow air into a mine (pressure-fan, blower), or to draw it out (suction fan.)

-An air-course cut in the side of a shaft or level, or constructed of wood. -A gang-way with rock on both sides.

i- A charge of powder exploding without producing the desired effect. The animals collectively of any given age or region. The plants are similarly called its Flora.

dislocation of the strata or the vein.

small vein falling into or Joining a larger one and often enriching It or other- wise affecting Its character.

370 Bulletin No. Vi.

Feldspars— Several allied species of minerals composed of silicates of alumina and of alkalies and lime. They crystallize In different systems. The triclinic group of feldspars is called collectively plagioclase. The principal species of feldspars are ortnoclase, albtte, labradorite. anorthite and ollgoclase. In granitoid rocks the feldspar grains may be detected by the shining of the faces of the cleavage planes. Those of labradorite are marked by minute parallel ridges called strias. The feldspars rank sixth in the scale of hardness, or next softer than quartz, and may be scratched with difficulty by the point of a knife. Feldspathic— Containing feldspar as a principal ingredient. Felsyte—A compact rock composed or ortnoclase feldspar and silica in microscopic

grains. Ferric Furnace— A high iron blast furnace, in the upper part of which crude bitumin- ous C"al is converted into coke. Ferromanganese— A n alloy of iron and manganese. Ferruginous— Containing iron.

Fine Metnlr- The iron or plate-metal produced in the refinery. Finery A charcoal-hearth for the conversion of cast into malleable iron. Fining— I. See Refining. 2. The conversion of oast Into malleable iron in a hearth or

charcoal Are. Fire-bricks— Kef ractory bricks of fire-clay or of siliceous material used to line furnaces. Fire-bridge- The separating low wall between the fire-place and the hearth of a rever-

beratory furnace. Fire-clay— A clay comparatively free from iron and alkalies, not easily fusible and

hence used for fire-bricks. Often found beneath coal-beds. Fire-damp— Light carburetted hydrogen gas. present in common air to the ex- tent of one fifteenth to one-thirteenth of volume the mixture is explosive. Fissile— Capable of being split, as schist, slate and shale. Fissure-vein- -A fissure in the earth's crust filled with mineral. Flaggy— Capable of being split into parallel-faced slabs thicker than slates. Flang—A two-pointed miner's pick. Flap-door— Applied to a man-hole door. Flat— A horizontal vein or ore deposit auxiliary to a main vein; also any horizontal

portion of a vein which is not elsewhere horizontal. Float-ore— Fragments of the material of an ore deposit found at a distance from Its

outcrop. Floor— 1. The rock underlying a stratified or nearly horizontal deposit, corresponding to the foot-wall of more steeply dipping deposits. 2. A Horizontal, flat ore- body. Flora— The plants collectively of a given age or region. See Fauna. Fluccan— Soft, clayey matter in the lode. Flume-A wooden trough, sluice or race for conveying water.

Fluorspar— Fluoride of calcium; a mineral which often forms veinstone and is usually finely colored,— green, purple, yellow, blue. etc. It is the fourth In the scale of hardness, or next higher than calcite, and may be scratched by a steel point. It crystallizes in the Isometric system. Common In veins in the Animike slates of the Thunder bay district. Fluting- Smooth gutter-like channels or deep smooth furrows worn In the surface of

rocks by glacial action. Fluviatile— Pertaining to rivers.

Flux— In metallurgy, auy substance added to facilitate the smelting of another. Foliated— Leaf-like. The meaning is similar to that of laminated, but the latter is now generally used to indicate a finer or more parallel division into layers, foliation being applied rather to the approximate parallelism of the layers in such rocks as gneiss and schist. Foot-wall— The wall of rock upon which the ore deposit seems to lie. Ft tot-way— The series of ladders and sollars by which men enter and leave a mine. Foraminifera— Minute marine animals of the lowest and simplest organization, but

having beautiful shelly coverings. Forefield— The face of the workings. The forefield-end is the end of the workings farth- est advanced. Fore-hearth A projecting bay in front of a blast-furnace hearth, under the tymp. In open-front furnaces it is from the fore-hearth that cinder is tapped. See Dam and Tymp. Forge— 1. An open or semi-open hearth with a tuyere. 2. That part of an ironworks where baUs are squeezed and hammered and then drawn out into puddle-bars by

?;rooved rolls. nder— The slag from a forge or bloomary. Forepale or forpale— The drawing of timbers or planks horizontally ahead at the work-

iug face, to prevent the caving of the roof In subsequent driving. Formation— "Any assemblage of rocks which have some character in common, whether

of origin, age or composition."— LyeVL In chronological geology formations

constitute as it were the units, and several formations may go to make up a

system. The word is often loosely used to indicate anything which has been

formed or brought into its present shape. Fowfl-Llterally anything "dug up," but how restricted to organic remains, and not

properly applied to any mere mineral substance.

Fossil ore— Fossil lferous red hematite. Fracture— The character or appearance of a freshly broken surface of a rock or mineral.

Peculiarities of fracture afford one of the means of distinguishing minerals and

rocks from one another. Fragmentary rock*— Rocks composed of fragments, whether large or small, broken from

j re-existing ones. See Clastic. Freestone -A variety of sandstone which may be freely dressed by the stone-cutter. Friable— Easily broken, or crumbling naturally. Fundamental rocks— Those which form the foundation, substratum, basis or support of

others. %

Iron Ores Of Minnesota. 371

IPurpen— A round rod used for sounding a bloom a ry fire.

Furnace— 1. A structure in which heat is produced by the combustion of fuel. 2. A structure In which, with the aid of heat so produced, the operations of roasting, reduction, fusion, steam generation, dessiccation, etc.. are carried on, or. as In some mines, the up-cast air-current Is heated to facilitate its ascent and thus aid ventilation

Fuse— A tube or casing filled with slow burning material, by means of which a blast is Ignited and exploded.

Gabbro— An Igneous rock consisting of a crystalline granitoid mixture of a tricllnlo feldspar and d tallage, the latter being a variety of augite with perfect cleav- age in one direction. Oabbro is often accompanied by. or partially composed of, titaniferous magnetite or ilmenite.

Gad— I. A steel wedge. 2. A small iron punch with a wooden handle, used to break up ore.

Galena— The commonest ore of lead, of which it is the sulphide. When freshly broken It has a bright silvery appearance, from which It has been called lead-glanco. It crystallizes in the cubic system. Galena nearly always contains more or less silver; too little to extract profitably in tho majority of cases.

Gallery— A level or drift.

Ganister—A mixture of ground quartz and fire-clay used in lining Bessemer converters.

Gang— 1. Amine. 2. A set of miners.

Gangue— The mineral associated with the ore in a vein.

Gangway— 1. A main level. 2. A wooden bridge.

Gas-furnace— A furnace employing gaseous fuel.

Gash— Applied to a vein wide above, narrow below, and terminating in depth within the formation it traverses.

(Tote, Gate-way or Gate-road— 1. A road or way underground, for air, water or general passage; a Gangway. 2. The aperture In a founder's mould, through which the molten iron enters.

Gear-1. The working tools of a miner. 2. The mechanical arrangement connecting a motor with its work.

Geode—A cavity, studded around with crystals or mineral matter, or a rounded stone containing such a cavity.

Geological Formation— Groups of rocks of similar character and age are called forma- tions. The miners of Minnesota frequently apply the term to the rocks of a particular region and not of a geological period.

GeoUitry— "The science which investigates the history of the earth." Geikie.

Girafe—A car of peculiar construction to run up an incline.

Girth— In square-set timbering, a horizontal brace In the direction of the drift.

Glocker— A large accumulation of ice formed from snow falling upon high land and gradually sliding to lower levels. When a glacier reaches the sea it gives rise to Icebergs.

Glance— A term formerly used to designate various minerals having a splendent lustre, as silver-glance, lead-glance, etc. These minerals are generally tho sulphides of the metals so termed.

Gneiss— A foliated crystal line rock of a general granitoid composition. The common- est varieties are mica-gneiss, consisting of feldspar, quartz and mica, and hornblende gneiss, or syenite gneiss, consisting of feldspar, quartz and horn- blende. ,

Goaf— An excavated space, also the waste rock packed In old workings.

Goaves—0\d workings.

Gob flee Goaf.

Gopher or Qaphtr-dri /f— An irregular prospecting drift, following or seeking the ore without regard to maintenance of a regular grade or section.

Gossan or Giazan—Uyd rated oxide of iron, usually found at the decomposed outcrop of a mineral vein.

Gouge— A layer of soft material along the wall of an ore deposit, favoring the miner. by enabling him, after "gouging" It out with a pick, to attack the vein from tne side.

Grapnel— An implement for removing the core left by an annular drill In a bore-hole, or for recovering tools, fragments, etc.. fallen into the hole.

Grampus— The tongs with which bloomury loup and billets are handled.

GrantU— A homogeneous crystalline granular mixture of feldspar (usually ortho- clase) quartz and mica, showing no foliation or tendency to break in one direc- tion more than In another. It may still be called granite when the per cent, of mica Is very small. Granites may have been of eruptive origin, but their con- stituents show ihey were, in that case, produced by a secondary fusion of sedi- mentary rock. They often contain trlclinlc feldspars, and also hornblende.

Granite Family— The group of crystalline, homogeneous or non-foliated rocks, resemb- ling granite, such as syenite, quartz-syenite, granityte. and all varieties of gran re itself.

GranUelle— Binary granite, composed of feldspar and quartz.

QranttyU—A mixture of orthoelase and ollgoclase with a little quartz and mica.

Granitoid Rocks— The granite family includes rocks which have a general resemblance to granite, such as syenite, quartz-syenite, granulyte, granityte, granitello, massive gneiss, etc.

Granulyte— A crystalline rock composed of orthoclase and quartz with garnet ami ky- anite (a silicate of alumina) as accessory minerals. Granulyte may be of erup- tive origin notwithstanding its some times schistose character.

Graphic Granite— A variety of binary granite in which thequartz isis|M>scd in the feld- spar In such a way that In cross section il has some resemblance to Hebrew and Arabic writing, and from this circumstance it derives Its name.

GropMte— Called alno black lead and plumbago, because It can be used for marking like lead, although this metal does not enter into Its composition. It consists of pure carbon, with a slight admixture of Iron.

372 Bulletin No. Vi.

Grass-roots— A miner's term equivalent to the surface.

Grating— The plate of perforated metal or sieve fixed in the openings in mortar or stamper boxes in gold or silver crushing mills.

Greenstone— A general name for the compact granular trap rocks, such as dioryte, diabase, basalt, etc.. and is a convenient term for use in the field, where It is difficult to distinguish these rocks from one another. Trap has too wide a range of meaning,

Greywacke—A gray, ashy looking rock,consisting of a mixture of grains of feldspar and quartz with some amorphous mineral, and often containing rounded and an- gular fragments of all sizes, from that of peas up to boulders of a quartz-feldspar rock. These are often so abundant as to constitute a breccia-conglomerate. Greywackes are very common rocks in the Keewatin system in the vicinity of Vermilion lake.

Grit— Sandstone in which the grains are sharper or more angular than usual.

Growan— Decomposed granite; sometimes the granite rock.

Groove or Grove (from Grube)— A mine.

Grundy— Granulated pig iron.

Gubbin—A kind of iron-stone.

Guides— The timbers at the sides of the shaft to steady and direct the cage.

Guillotine— A machine for breaking iron with a falling weight.

Gully—A small valley with steep sides, usually cut out of clay or earth.

Gunnies or Gunniss— The vacant spaces left where the lode has been removed.

Gypsum— Sulphate of lime, usually white and crystalline granular. Selenite is the pure crystalline form, and splits into plates which are very transparent. It Is very soft, and is the mineral which constitutes the second degree of hard- ness, talc being the first. Gypsum occurs in beds in the Jura-Trias. Selenite crystals are found in the drift throughout western Minnesota.

Hack— I. See Pick. 2. A sharp blade on a long handle, used for cutting billets in two.

Hade— See Underlay.

Hair plate— See BUwmary.

Hanging-side, or Hanging-wall or Hanger— The wall or side above the ore-body.

Hardness of minerals— Mineralogists have adopted a conventional scale of hardness for minerals. It is divided into ten degrees, and the following minerals are used for reference as standards: ITalc, 2 Gypsum. 3 Calcspar, t Fluorspar, 5 Apatite, 60rthoclase feldspar, 7 Quartz, 8 Topaz, 0 Corundum, 10 Diamond. There is no scale of hardness for rocks, which are generally composed of mixtures of differ- ent minerals, but some varieties may be referred approximately to the scale for minerals.

Head-gear— That part of deep-boring apparatus which remains at the surface.

Heading— 1. The vein above a drift. 2. An interior level or air-way driven In a mine. 3. In long-wall workings, a narrow passage driven up in a gangway in starting a working in order a give a loose end.

Head-piece— See Cap.

Headway— See Cross heading. The headways are the second set of excavations in post and stall work.

Heap— The refuse at the mouth of the pit.

Hearth— 1. The floor or sole of a reverberatory. 2. The crucible of a blast furnace.

Heat— One operation in a heating furnace, Bessemer converter, puddling furnace, or other furnace not operating continuously.

Heating-furnace— -The furnace in which blooms or piles are heated before hammering or rolling.

Heave— A miner's term for an upthrow. See Dislocation.

Heavyspar—B&rytes or sulphate of barium. Celestite or sulphate of strontium is also a neavyspar easily mistaken for barytes. The carbonate of barium is witherite; that of strontium is strontlanite.

Height-of-Land— See Water Shed.

Helve- A lift-hammer for forging blooms.

Hematite or Hcematite— One of the commonest ores of iron. It is the peroxide or sesqui- oxide. and when pure contains about 70 per cent, of metallic iron and 30 of oxy- gen. It may be readily distinguished from magnetic and titanlferous iron ore by its red streak and. powder, the others giving a black streak. Hematite is sometimes mixed with sufficient magnetite to cause it to adhere to the magnet. The h yd rated variety of this ore is called limonite or brown hematite, the an- hydrous being often distinguished as red hematite. It contains about 14 per cent, of water and gives a brown or yellowish streak. It is not always compact —yellow ochre, bog iron ore, umber, terra sienna, etc., being varieties of it.

Hercules powder— See Explosives.

Hexagonal— having six angles, and consequently six sides. Crystals of quartz, apatite etc., are examples.

Hitch— 1. Minor dislocation of a vein or stratum not exceeding in extent the thick- ness of the vein or stratum. 2. A hole cut in the side rook, when this is solid enough, to hold a cap set with timbers, permitting the leg to be dispensed with.

High explosive— An explosive or detonating compound developing more intense and in- stantaneous force than gunpowder. Most high explosives in general use con- tain nitro-glycerine. See Explosives.

Hog-back— 1. A sharp anticlinal, decreasing in bight at both ends until it runs out. 2. A ridge produced by highly tilted strata.

Hollow-fire - A kind of hearth with blast, used for reheating the stamps produced in the South Welsh process of firing, or the bars of blister-steel, in the manufacture of shear steel. Homogeneous metal— A variety of ingot-metal produced by the open hearth process. See

Steel. Hopper— 1. A trap at the foot of a shoot for regulating the discharge. 2. A place of deposit for ore.

Iron Ores Of Minnesota. 373

Horizon— In geology, refers to the age or place of rocks in the chronological scale. A rock is spoken of as belonging to a higher or lower horizon according as it is newer or older than some other rock.

Hornblende- A very common mineral; so called from its hornlike cleavage and its lus- tre ; also known as am phi bole and amphibolite by the French. Usually dark green and blackish, but occasionally of light colors. It enters largely into the composi- tion of dioryte, rendering this rock very touh. It is also a constituent of syen- ite, soi'ie gneisses, etc. It is a silicate of magnesia, iron and lime, and its chemical composition differs but little from that of pyroxene or auglte, this mineral be- ing distinguished from it by crystalline form, etc. The principal varieties of hornblende are tremolite, actinolite and true asbestos.

Hornstone— The cherty and chalcedonlo varieties of quartz.

Hone— A mass of country rock enclosed in a vein and almost or entirely surrounded by the vein stuff; sometimes called boulders. See Salamander.

Hot-bed— A platform In a rolling-mill on which rolled bars lie to cool.

Hot-blast— A\r forced Into a furnace after having been heated.

Hudge—Aa iron bucket for hoisting ore.

Hummocky— Lumpy, or in small uneven knolls. Huronian System— Th

'he great system of primordial or sub-crystalline rocks belonging between the Keewatin (below) and the Cambrian or Lower Silurian system (above). This name was first given by Sir William Logan and Dr. T Sterrv Hunt to these rocks as they were largely developed on the north side of lake HuroQ, but the term has been pretty generally extended downward to include all the stratified crystalline rocks to the Lauren tian. It is a synonym forTaconic.

Hutch— A low car suited both for running in a level and hoisting in a cage.

Hydrated— Containing water in chemical combination, and hence in a definite propor- tion in each case, as gypsum which contains "water of crystallization," hydrate of lime, or lime which has absorbed water on slacking, hydrated oxide of iron, or yellow ochre, which can be readily converted into the anhydrous or red ox- ide by driving off the water by heat

Hydraulic Cement Cement which sets under water. The rocks which.on being calcined and ground very fine yield this cement must contain, in addition to lime, certain proportions of alumina, silica and magnesia. A little iron is also usually present.

Hydraulic Mining— Washing down gold-bearing earth by means of a large and power- ful Jet of water brought from a considerable night and directed by a hose-pipe so as to have a pressure of from 50 to 100 pounds to the square inch. This pro- cess has been extensively used in California and has also been tried in the Chaudiere gold region of the Province of Quebec.

Hydro-carbons— Substances composed of hydrogen and carbon, as bitumens, parafflne, petroleum, benzine, etc.

Hypogene—A term proposed by Lyell for all nether-formed rocks, i.e. rocks which have assumed their present form at great depths beneath the surface, whether orig- inally stratified or unstratifled. The former belong to the metamorphic and the latter to the plutonlc group.

Iceland-spar— The transparent variety of calcspar, found in perfection in Iceland. It possesses the property of double-refraction of light. If a dark line be viewed through it, it will appear as two parallel lines.

Igneous— Connected with subterranean heat. Igneous rocks are those which have evi- dently been once In a molten condition. Those which have cooled at or near the surface, Much as lava mid amygdaloid are called volcanic rocks; while those which have cooled at depths and under great pressure, such as granite, syenite, dioryte. etc.. are called plutonlc rocks.

JImenite— Titanic iron or menaccanite; a black heavy mineral like magnetite and com- posed of black oxide of iron with a varying quantity of oxide of titanium. It occurs similarly to magnetite. The black iron ores associated with the plagio- claseprtricllnlc feldspar rocks appear to be prone to contain titanium. No prof- itable process has yet been discovered for the extraction of Iron from ores con- taining more than a very small percentage of titanium.

Impervious— Impassable; applied to strata such as clays, shales, etc., which will not permit of the penetration of water, petroleum or natural gas.

Impregnation— An ore-deposit consisting of the country-rock impregnated with ore, usually without definite boundaries.

Incline— 1. A shaft not vertical: usually on the dip of a vein. See Slope. 2. Aplane,not necessarily underground.

Indicator— An instrument for showing at any time the position of the cage in the shaft.

Indurated- Hardened; applied to rooks hardened by heat, pressure, or the addition of some ingredient not commonly contained in thermic referred to, as marl indu- rated by carbonate of lime.

InJUtration— The deposition of matter among the grains or pores of a rock by the per- meation or percolation of water carrying it In solution.

Infiltration theory— The theory that a vein was filled by the infiltration of mineral so- lutions.

Ingot— A cast bar or block of metal.

Injection theory— The theory that a vein was filled first with molten mineral.

Inorganic— Not organic; unconnected with animal or plant structure.

In place- Of rock, occupying, relative to surrounding masses, the position that it had when formed.

In situ— In position or place; applied to solid or fixed rocks as opposed to those which are loose and may have been t ransported.

Inspissated— Thickened as by evaporation and oxidation, as for example the pitch or gum resulting from petroleum after long exposure.

Intake— The passage by which the ventilating current enters amine. See Downcast, which is more appropriate for a shaft; Intake for an adit.

374 Bulletin No. Vi.

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Intercalated— In geology means interposed or placed between, as beds of one kind placed between or interstratifled with those of another kind.

Interstratifled— Or interbedded . Strata laid between or alternating with others.

Intrusive— Applied to igneous rocks which have been forced between or into the midst of others.

Iridescent— Colored like the rainbow. A play of colors such as is seen on the peacock's tail. Labradorite and some other feldspars show it. The tarnish on the surface of coal, copper pyrites, etc., is sometimes iridescent.

irtmThe principal varieties of iron are wrougltt-iron and cast-iron (see Pig-iron). -iron, also called bar-iron and weld-iron, is the product of the forge or the puddling furnace; cast-iron of the blast furnace. The former approaches pure iron; the latter is an alloy of iron and carbon. Steel, except some of the so-called "low" or " mild" steels, which are more nearly wrought-iron (fused and cast), stands between them, having less carbon than, cast- iron and more than wrought-iron. Some of the carbon in cast-iron is usually segregated dur- ing cooling, in the form of graphite, and this determines the grade of the iron as No 1 foundry (the most graphitic, coarsely crystalline, soft and black). No 2 foundry (less open in grain). gray /wye or mill iron (still closer in grain, suitable for puddling), mottled, (spotted with white-iron), and white (hard, brittle, readily crystalline containing its carbon mostlv in alloy with the iron, and showing no -visible graphite). These grades are called simply No. 1, 2, 3, etc. So-called *tf- ver gray, glazy or carbonized iron is usually an iron rendered brittle by excess of silicon. Ingot iron, see steel. Anthracite, charcoal and coke iron, are names given to pig-iron according to the fuel with which it is made.

Iron hat— See Gossan.

Iron-ores— Magnetic .( Magnetite protoperoxlde) specular (hematite proper) red hematite (an- hydrous peroxide;, brown iron ore, hematite, brown liematite. limonite, etc., (hyd rated peroxides), spathic (siderite, carbonate), clay ironstone (black band, argillaceous siderite.)

Iron Pyrites— Or simply pyrlte; bl-sulphide of iron. A hard, heavy, shiny, yellow min- eral, generally in crystals of the cubic system. It may be distinguished from copper pyrite by being of a paler yellow color, harder and giving a black pow- der, whereas copper pyrites gives a yellow powder. When struck by steel, or when two pieces are struck briskly together sparks of fire are emitted, accom- panied by the odor of sulphur. A very common mineral. Marcasite has the same composition, but is white and crystallizes differently. Pyrrhotite or mag- netic pyrites is the monosulphide of iron and is of an iron-gray to bronze color.

Ironstone— Any ore of iron from which the metal may be smelted commercially, but usually restricted to stratified ores, especially to clay- ironstone -the ore from which most of the iron of Great Britain and Pennsylvania has been made.

Isochemic lines— Planes or lines of equal content of phosphorus in any single layer of iron ore.

Isoclinal— Applied to strata which have been so completely overturned that the upper fold or inverted portion dips in the same direction as the corresponding lower portion.

Jars— A part of percussion-drilling apparatus for deep holes, which is placed between the bit and the rods or cable, and which by producing at each up-stroke a decided jar of the bit jerks it up though it may be tightly wedged in the hole.

Jasper— Compact opaque varieties or quartz with conchoidal fracture and usually ca- pable of a high polish. The colors are red. brown, green spotted, nearly white, etc. When it carries hematite in the Keewatln it has been named jaspflyte.

Jig-Chain— A chain hooked to the back of a skip and running around a post, to prevent too rapid descent on an inclined plane.

Jiaging— One of the operations in the dressing of crushed ores, such as those of lead, copper, etc. The usual process consists In shaking or jerking the ore In a wire- bottomed sieve suspended in a vat of water. This allows the fines to pass through and they are afterwards treated In buddies, while the rest becomes sorted according to its relative gravity. The waste fragments are scraped off the top, the process being called skimping.

Joints— The nearly vertical division-planes which traverse nearly all rocks. They are called backs by quarrymen.

Jump— 1. To take possession of a mining or other claim alleged to have been forfeited or abandoned. 2. A fault or dislocation of a bed or vein.

Jumper— A short steel drill for boring holes in rock for blasting or for splitting by gads.

Jurassic Sunt em— The system which succeeds the Triassic; so called after the Jura mountains on the border betwiou Switzerland and France. It corresponds with the Oolite of England.

Karnes— Ridges of sand and gravel of which the stratification Is rudely parallel to the slopes of the surface. Their origin has not been satisfactorily accounted for.

Kaolin— Clay, usually very light in color, derived from the decomposition of the sili- cates of the crystalline rocks. It is used for the manufacture of porcelain.

Kawish iivin— The iron-bearing belt of the Keewatln. The greenstone, or diorltic, (upper) part of the Keewatln.

Keewatin— From the Chippewa, meaning Northwcxt. Applied by A. 0. Lawson to the semi-crystalline schists that immediately follow the crystalline schists. They consist of silky mica schists, gray wackes and chloritic schists, with agglomer- ates and tuffs; the whole being largely of volcanic origin. Contains the iron ore at Tower and Ely. „

Klbhall or Kibble— An iron bucket for raising ore.

Kies— The pure or separated sulphides, as distinguished from the vein-matter in bulk.

Kiln— A large receptacle for calcining ores, limestone, etc.

Kindly— A miner's term for a rock which is considered congenial or likely for carrying ore.

Iron Ores Of Minnesota. 375

Kith— The blast-furaacemen's name for the graphite segregations seen in pig-iron and in the cinder of a furnace, making a very gray iron.

Knobbing-fire—A bloomary for refining cast-iron,

Krupp washing process -The removal of silicon and phosphorus from molten pig-iron bv running it Into a Penwt furnace, lined with iron oxides. Iron ore may also be added, and the bath is agitated by rotation for five to eight minutes only.

Labradorite— Lime soda feldspar; a silicate of alumina, lime and soda. Crystalliza- tion, triclinlo. See Feldspar.

Labor— Labor; work; a working. This term is applied in mining to the work which is actually going on, and to the spaces which have been dug out. It includes galleries, cavities and shafts.

Laboratory- -l. A place fitted up for chemical analyses, etc 2. The space between the fire and flue bridges of a reverberatory furnace in which the work is per- formed ; also called the kitchen and the heatth.

Laccolitt—A mass of igneous rock which has not reached the surface, but has been forced between two beds of rock where it has spread out. The typical ex- amples occur in the Henry mountains.

Lacustrine deposits— Deposits formed in the bottom of lakes.

Lagging— Planks, slabs or small timber placed over the caps or behind the posts of the timbering, not to carry the main weight, but to form a ceiling or a wall, to prevent fragments of rock from falling through.

Lander— The man at the shaft-mouth who receives the kibble.

Landslides or slips— Large masses of clay, earth or rock which have lost their support and slid down, sometimes temporarily blocking up streams or railroads.

Launder— A spout or trough for carrying water for a short distance.

LaurenUan System— The lowest rocks of the Archaean, principally acidic gneisses and granites.

Lateral— Belonging to the sides, or to one side.

Lead— An auriferous deposit following the former bed of a stream now covered by superficial deposits. In general use quartz veins are called leads.

Leader— A small ore shoot leading to larger bodies.

Lean— Applied to poor ores or those containing a lower percentage of metal than is usually worked.

Leap— A fault. See Jump.

Lenticular— Shaped approximately like a double convex lens. When a mass of rock thins out from the centre to a thin edge all round it is said to be lenticular in form.

LentUU— An isolated mass of rock containing fossils of a fauna older than the strata in which it occurs, though of cotemporary age with those strata.

Level— A horizontal passage or drift into or in a mine. It is customary to work mines by levels at regular intervals in depth numbered in their order below the sur- face or below the adit if there bo one.

Leg— A prop of timber supporting the end of a stull, or the cap of a set of timber.

Lignite— See Coal.

Limestone— A rock composed of carbonate of lime; of all colors and varieties in texture from compact or amorphous to coarsely crystalline. White marble is a finely crystalline variety. Chalk is a soft form Limestone may be distinguished from other rocks by being easily scratched with a knife and by effervescing when acid is placod upon ft.

Limonite— Brown hematite; hydrated oxide of iron. See Hematite.

Lithology or Petrology— The study of rocks as such; a branch of geology which is being much developed in recent years. By making thin sections and examining them under the microscope the nature of a rock may be determined as well for most purposes as by chemical analysis.

Loam— A mixture of sand and clay. If decayed vegetable matter be added, it as- sumes a dark color and is called vegetable loam.

Location— i The act of fixing the boundaries of a mining claim according to law. 2. The claim itself.

Loch— See Vug.

Lode— Strictly a fissure in the country-rock filled with mineral; usually applied to metalliferous lodes. In general miner's usage, a lode, vein or ledge is a tabular deposit of valuable mineral between definite boundaries. Whether it is a fissure formation or not is not always known, and does not affect the legal title under the United States federal and local statutes and customs relative to lodes.

Loess— A peculiar deposit like fine silt found in some parts of northern Europe, north- ern China and in the north-western United States.

IjOng-Ton$— A trough for washing gold-bearing gravel or earth.

Long-wall— A method of mining coal and iron ore by which a whole seam or bed is taken out as the working faces progress, and the roof is allowed to fall in behind the workers, except where passages must be open, or where the gob being packed in the space formerly occupied by the coal or ore, prevents caving. According as the work of extraction begins at the boundary of the winning, and converges hack to the shaft, or begins nearest the shaft and extends outward to the boundaries of the property, it is called long-wall retreating or long-wall advancing.

Loop— See Loup.

Loop-drag— An eye at the end of a rod through which tow is passed for cleaning bore- holes.

Lorry— A hand-car used on mine tramways.

Lost level— "Level" is "lost" when a gallery has been driven with an unnecessarily great departure from the horizontal.

-Loup—The pasty mass of Iron produced in bloomary or puddling furnace. See Puddle- ball.

376 Bulletin No. Vi.

Lowe—A light. A "piece of lowe" is part of a candle.

Lum-~ A chimney aver an upcast pipe.

Lurmann front— An arrangement of water-cooled castings through which iron and cinder are tapped from the blast furnace, thus avoiding the use of forehearth.

Isytng-waW-See Foot-wall.

Lustre— The character of the light reflected by minerals; it constitutes one of the means of distinguishing them.

Jjydian-stone—A compact or close grained, nearly black, variety of jasper. A smoothed surface of this stone is used for trying the streak of gold, the color of which af- fords an index to its purity.

Macroscopic— Readily seen by the naked eye. On a large scale compared with micro- scopic; same as megascopic.

Magnesian Limestone— See Dolomyte.

Magnetic Iron Pyrites— See Iron Pyrites.

Magnetite— Or magnetic iron ore. Black oxide of iron. In addition to its magnetism it may be distinguished from hematite by yielding a black streak and powder.

Mainway—A gangway or principal passage.

Malleable castings— Small iron castings made malleable by "annealing" or deoarburiz- ing by cementation in powdered hematite or other oxide of iron.

Mallet— The sledge-hammer used for striking or beating the borer.

Maltha— The pitch or "gum" resulting from the drying up and oxidation uf petroleum, as when it has reached the surface of the ground.

Mammittatcdr— Having the form of paps or breasts.

Mammoth— A fossil elephant allied to the living species, but larger.

Manganese— A metal chemically related to iron. The black oxide, pyrolusite, the gray oxide, manganite and the earthy oxide, wad, are used in the arts. Manganese is used in toe manufacture of Bessemer steel.

Man-hole— The hole in a sollar through which men pass upon the ladder or from one ladder to the next.

Mantle— The outer wall and casing of an iron blastfurnace, above the hearth.

Manway—A small passage, used by workmen, but not for transportation.

Marble— A variety of moderately soft rocks capable of taking a good polish is called marble. The commonest are compact and crystalline limestones and dolomy tes and serpentine.

Marcasite—See Iron Pyrites.

Marl- Usually applied to a soft or friable natural mixture of clay and lime.

Marly— Resembling marl.

Martin process— Called also the Siemens-Martin and the open hearth process. See Steel.

Massive Rocks— Those which have no stratification or lamination, as greenstones, granite, syenite, etc.

Mastodon— A genus of extinct elephantine mammals, having conical protrusions on the grinding surfaces of their teeth, whereas the mammoth has flattened trans- verse ridges.

Matrix— The rock or earthy material containing a mineral or metallic ore; the gangue.

Matt or Matte— A mass consisting chiefly of metallic sulphides obtained in the fusion of ores.

Maul— A large hammer or mallet.

Measures— A general name for stratified rocks.

Megascopic— Visible to the unaided eye. Macroscopic.

Mei-chantrtrain— A train of rolls for reducing iron piles or steel ingots, blooms or billets to bars of the various round, square, flat or other shapes, known as merchant iron or steel.

Mesozoic— Or secondary ; the "middle-life" period or age. It is the third of the five grand divisions of geological time. It includes ( in ascending order), the Triassic, Jur- assic and Cretaceous systems.

Jfctol--This term is applied by miners both to the ore and to the metal extracted from it. It is sometimes used for vein, and even for a mine itself. It includes all the rocks met with in mining ores. Road metal is rock used in macadamizing roads

M etaUiferous— Carrying metal.

Metal-notch— See Tap-nole.

Metamorphic — Applied to the rocks which have been changed in form and internal structure. Heat, pressure and time acting on the constituents of rocks have been the main causes of rnetamorphism, converting ordinary and soft sediment- ary deposits into crystalline and hard rocks.

Metamorphism— The change in form, etc.. which some rocks have undergone, or the process itself. Alteration has a different meaning, but is sometimes used synonymously.

Meteorite— See Aerolite.

Mica— A common mineral easily recognized by Its glistening appearance and from the fact that it may be split into very thin leaves which are flexible. It enters into the composition of mica-schist, gneiss, granite and other crystalline rocks, and is found in scales in sands and sandstones derived from their disintegration. Ignorant persons sometimes speak of it improperly as isinglass, which is made from the swimming bladder of the sturgeon.

Micaceous— Containing mica or largely composed of it.

Mica-schist— A foliated crystalline rock composed of alternate layers of quartz and mica in various proportions, the typical one being about two-thirds quartz to one-third mica; although the proportion of the latter generally appears greater than it is. because the rock splits along the mica foliar thus showing the mica alone on the flat surfaces. The true composition may be seen by looking at the squarely broken edges. Orthoclase is a common constituent.

Microscopic — So small as to be seen only by the microscope.

Iron Ores Of Minnesota. 377

t

MQl—1. That part of an iron works where puddle-barn are converted into merchant iron, i. e., rolled iron ready for sale in bars, rods or sheets. 2. By common usage any establishment for reducing ores by other means than smelting; more strictly, a place or a machine in which ore or rock is crushed. 3. An excavation made in the country rock by a cross-cut from the workings on a vein, to obtain waste for gobbing, ft is left without timber so that the roof may fall in and furnish the required rook. 4. A passage through which ore is shot underground.

Millstone Grit— In Great Britain this name is given to a part of the Carboniferous system consisting principally of sandstones, below the Ooal Measures; it is also some- times used for the equivalent group in America.

Mine— In general, any excavation for minerals or ores. More strictly, subterranean workings, as distinguished from quarries, placer and hydraulic mines, and surface or open works.

Mineral— Scientifically, any inorganic substance having a definite chemical composi- tion and crystallizing in definite forms. Each of these constitutes a mineral species. See Rock. But the word means literally anything dug out of the earth, and in this sense includes everything except living or recently dead organic matter. Many mineral substances, such as coal, some limestones, etc., are composed of mineralized organic matter.

Mineralization— The conversion of a substance into mineral, as peat into coal.

Mineralngy— The study or science of minerals; often confounded with geology, which see.

Miocene— The middle Tertiary system.

Molecule— An ultimate particle of matter, having a definite chemical composition.

Mollusca— One of the primary divisions or provinces of the animal kingdom : it embraces those so ft- bodied invertebrates most but not all of which are provided with shells, as oysters, snails, slugs, etc.

ifolyodenttc— Sulphide of molybdenum— a soft bluish black, usually laminated mineral occurring In veins of quartz, etc., having somewhat the appearance of graphite, but in most cases yielding a dark green mark on white paper. If found incon- siderable quantity it has a commercial value.

Monkey-drift— A small prospecting drift.

MonocUnal— Applied to any limited portion of the earth's crust throughout which the strata dip in the same direction.

Moonstone*— Pale, opalescent, almost transparent varieties of feldspars.

Moraines— Piles or ridges of boulder-drift or till which have accumulated at the sides (lateral) or lower extremities (terminal) of glaciers.

Mortar Box— The large deep cast-iron box into which the stamps fall and the ore is fed in a gold or silver stamp mill; also called a stamper-box.

Moss Aqatc—A variety of agate showing branching forms like those of moss.

Mountain Cork— An extremely light non-fibrous variety of asbestos.

Muck-bar— Bar-Iron which has passed once through the rolls.

Mullock— A term sometimes used for the accumulated waste or refuse rock about a mine.

Mundie— Iron pyrites. White mundlc Is mispickel.

Naphtha— A highly volatile liquid form of hydro-carbon.

Narrow work— The driving of gangways or airways; also any dead work.

Native— Occurring in nature; not artificially formed. Usually applied to pure metals, uncomblned .

Neutral— Of slags, neither acid nor basic; of wrought-iron, neither red short nor cold short; of iron ores, suitable for the production of neutral iron.

New Red Sandstone— The former name for the Permian system; it lies above the Car- boniferous, while the Old lied Sandstone lies below it.

Nickel— One of the metallic elements. It is a white metal, having a lustre like silver, but in its chemical relations It is more nearly connected with iron ; it is not, however, susceptible to oxidize like iron, and this is one of the properties which renders it so valuable for plating this metal. It has recently been found to give great toughness to steel, a most valuable property. Nickel is found most abundantly as a sulphide, associated with iron and copper.

Noble Metals— The metals which have so little affinity for oxygen e., are so highly electronegative; that their oxides are reduced by the mere application of heat without a reagent; in other words, the metals least liable to oxidation under ordinary conditions. The list includes gold, silver, mercury and the platinum group, palladium, iridium, rhodium, ruthenium and osmium.

Nodule— A concretion in a soft matrix, as the kidney stones found in clays almost everywhere. The bombs or kettles in the black shales of the Kamlnlstiqula and Whiteflsh valleys are only great nodules. The flints of the chalk of Eng- land and the detached lumps of clay iron-stone of the Carboniferous shales, etc, are other forms of nodules. Nodules have generally formed themselves around some fragment of either organic or inorganic matter as a centre or nucleus. Similar nodules are found in the Anlmike slates at Thomson, Minn , and on the Vermilion river northwest of Sudburv.

Nose- An accumulation of chilled material around the inner end of a tuyere in a smelt- ing shaft furnace, protecting and prolonging the tuyere.

Nugget— A lump of native gold, silver, platinum, copper, etc.

Obsidian— Dark-colored volcanic glass, the product of volcanoes of later geological times. It is a silicate of alumina, potash, soda and lime.

Oc/imc-Naturally occurring pigments, as yellow ochre or hydrated oxide of Iron. Blue, green, red, etc., clayey mixtures which may be used as coarse paints are also called ochres. Ochre Is also used as a mineraloglcal term for certain decom- position oxides, as bismuth, chrome, antimony and cobalt-ochres.

Old Nan— Ancient workings, goares.

Old Red Sandstone -See New Red Satulstone.

Oltyocfeue-Soda-lime feldspar; a silicate of alumina, soda and lime. Crystallization, triol 1 n Ic . See feidsixir.

378 Bulletin No. Vi.

Olivine— An earthy looking olive-green mineral, occurring In many trappean rooks.

Oolyte A limestone composed of small round grains, resembling fishes eggs, hence the name.

Opal— A gem composed of silica, with from 5 to 10 per cent, of water, having a "play of colors," or reflecting rainbow-like colors, with a brilliance or ''fire that gives to sound pieces a great value. Generally white and having a hazy or milky translucency.

Opatecent- Resembling opal.

Open Crib Timbering —Shaft timbering with cribs alone, placed at intervals.

Open Cut, Op*.n Pit— A surface working, open to daylight.

Open Front -The arrangement of a blast-furnace with a fore-hearth.

Open*— Large caverns.

Open Work - A quarry or open cut.

Ore— Properly speaking, combinations of metals with other substances, bat also ap- plied to the matrix from which native metals, such as gold, silver and copper are extracted. Sometimes, also, applied to other minerals won by mining, as apatite, barytes, etc.

Ore- Washer— A machine for washing clay and earths out of earthy brown-hematite ores.

Organic - Having organs for carrying on vital processes. Animals and plants are thus organized as distinguished from minerals or inorganic substances. When these organs or organic structures become mineralized they are fossils, or organic remains.

Orthoclase— Potash feldspar; a silicate of alumina and potash. Crystallization, mono- oli n ic. See feldspar.

Outcrop—The portion of a vein or stratum appearing at the surface, or immediately under the soil and surface debris.

Outlet— The passage by which the ventilating current goes out of a mine. See upcast.

Outlier— A portion detached from the main body, an island, as it were, surrounded by some other kind of rock.

Output -The product of a mine.

Overlap— When strata extend over an ancient formation further than those Immedi- acy preceding them, this extension is called an overlap.

Overturned— Where strata have been highly tilted till they pass the perpendioular, so that the lower fold becomes turned upside down, they are said to be overturned.

Oxidation— A chemical union with oxygen.

Oxide -A compound of the element oxygen with another element or other elements.

Pack— A wall or pillar built of gob to support the roof.

Pair or Pare— Two or more miners working in common.

Palaeontology— The science of ancient life, especially of animal remains, that of plant re- mains or fossil botany being called palseobotany.

Palaeozoic— The second of the five grand divisions, periods, or ages of the rocks of the earth's crust; so called from containing evidences of the most ancient life on the planet. The Palaeozoic period includes (in ascending order) the Taconio, Cambrian, Silurian, Devonian, Carboniferous and Permian systems.

Pane— The striking face of a hammer.

Panel— A heap of dressed ore.

Parachute— I. A kind of safety-catch for shaft cages. 2. In rod-boring a cage with a leather cover to prevent a too rapid fall in case of accident.

Paroxysm— In geology, any violent or sudden natural occurrence, as a volcanic erup- tion a sudden flood, etc.

Parting— A thin layer separating greater masses of rock, usually beds, as a parting of shale between beds of sandstone or limestone.

Parting Sand -Fine, dry sand, which Is sifted over the partings in a mould to facilitate their separation when the flask is opened.

Pass—1. An opening in a mine through which ore is shot from a higher to a lower level. See Shoot. 2. In rolling mills the passage of the bar between the rolls. When the bar passes "on the flat" it is called a "flatting-pa**"; If "on the edge," an "edging pass."

Patchy— Distributed In patches or In an Irregular manner as when ore occurs in bunches or sporadically.

Pavement— The floor of a mine.

Peat— A mass of vegetable matter formed in bogs and marshes. Its principal constitu- ent is sphagnum moss, but rushes, reeds, sedges, grasses, algae, etc., may also contribute. Peat sometimes accumulates to considerable depth; the lower por- tion becomes black and dense and Is used for fuel. The rotten wood found In the bottoms of swamps Is not peat, properly speaking.

Pegmatyte—A very coarse variety of granite, composed principally of quartz and crys- talline feldspar, but ofien holding sheets of mica. It usually forms great veins or enlargements of veins cutting mlca-schist, gneiss, etc. Formerly applied also to finer mixtures of o uartz and feldspar, called binary granite, now known asgranulyte and quartz-feldspar rock.

Permian System -The system next above the Carboniferous; formerly called the New Red Sandstone; the Devonian or next system below the Carboniferous being the Old Red Sandstone. This name (introduced in 1841 by Sir Roderick Murehi- son) is derived from the government of Perm In Central Russia, where the sys- tem Is well developed. There, as in the north of England, it is made up princi- pally of red sandstones.

Pernot furnace or Post-Pernot furnace— A revcrbrratory puddling or smelting furnace, hav- ing a circular, inclined, revolving hearth.

Peter or peter out— To fail gradually in size, quantity or quality.

Petrify— To become stone. Organic substances, such as shells, bones, wood, etc., em- bedded In sediments, become converted into stone bv the gradual replacement of their tissues, particle by particle, with corresponding amounts of Infiltrated mineral matter. Thus not only the outward forms but even the minutest de- tails of the organic tissues are preserved.

Iron Ores Of Minnesota. 379

Petroleum— Or rock-oil; liquid hydrocarbon. Formed in large quantities in some rooks which contain organic matter.

Petrology— See Lithologu.

PetroeUex—A compact siliceous felsyte having a fracture like jasper distinguishable from it in being fusible before the blowpipe.

Pith— A pick-axe with one or two points.

Pig —An ingot or cast bar of metal .

PiQ-iron— Crude cast iron from the blast furnace. When the furnace is tapped the molten iron flows down a runner moulded in sand, from which it enters the sows or lateral runners, flowing from these again into the pig-lied*, the separate parallel moulds of which form the pigs. In each bed the ingots lie against the $ow like suckling pigs, whence the two names. See Iron. Mine-pig is pig iron made from ores only ; cinder-pig, from ores with admixture of some forge or mill-cinder.

Pfle. 1. The fagot or bundle of flat pieces of iron prepared to be heated to welding heat and then rolled. 2. To make up into piles or fagots.

PiUars— Portions of the vein or bed left standing to support the roof.

Pillar-and-*tall—8ee Post-and-mtall.

Pinched— Where a vein narrows, as if the walls had been squeezed in. When the walls meet the vein is said to be pinched out.

Pipe or pipe-vein— An ore-body of elongated form.

Pipe-ore— Iron ore(limouite) in vertical pillars, sometimes of conical, sometimes of hour-glass form embedded in clay. Probably formed by the union of stalac- tites and stalagmites in caverns.

Pit— A shaft; an open mine or working.

Pitch— The inclination of a vein, or of the longer axis of an ore-body, different from dip or strike, but lying in the same plane.

Pitch-bag— A ba.g covered with pitch In which powder is enclosed for charging damp holes.

Pitchstone-A dark glassy or looking Igneous rock, occurring as dykes, and also as beds which have flowed upon the former surface. It is a natural glass with splintery fracture, although translucent only on thin edges, and has the com- position of felsyte.

Placet"*— Gold-bearing sand and gravel deposited on the bed-rock.

Plagioclase— The trlciinic feldspars are called collectively plagioolase. The principal triclinlc feUsparsare albite, anorthite, labradorite and oligoclase. As constit- uents of rocks they occur generally in small crystalline grains, and without a microscopic examination it lsdifHcult to distinguish them in this form from one another; hence this term is very convenient for use in the field.

Plane— An incline with tracks, upon which materials are raised in cars by means of a stationary engine or are lowered by gravity.

Plank-timbering— The lining of a shaft with rectangular plank frames.

Plank-tubbing— The lining of a shaft with planks, spiked on the inside of curbs.

Plaster of Paris— A plaster made from gypsum by grinding and calcining it; so called from its manufacture near Paris in France. In general this term has been adopted for gjrpsuni in any form.

Plastic Clay— In England, applied to certain clays of the Eocene system, but In general means clay suitable for moulding into any form.

Plot— The map of a survey, in horizontal projection.

Piatt— An enlargement of a level near a shaft, where ore may await hoisting, wagons pass each other, etc

Pleistocene System— Or Post-Pliocene. The system which succeeds the Pliocene. It embraces the remains of a fear extinct species of animals, especially of mam- mals, while those of the Recent belong entirely to species still living.

Plicated— Folded together, as in highly inclined and contorted strata.

Pliocene System— The uppermost of the Tertiary systems; divided into the Older Plio- cene, in which from 35 to 50 per cent, of its embedded species are still living, and the Newer Pliocene, in which the proportion Is from 90 to 05 per cent.

Plug— A hammer closely resembling the bully.

Plumb— 1. Vertical. 2. Soft.

Plumbaginous— Containing plumbago, as plumbaginous schists; some crystalline lime- stones are also plumbaginous.

Plumbago— Graph i te.

Plunger— The piston of a force pump.

Plutonic Rocks— Igneous rocks which have cooled at a considerable depth from the sur- face and under great pressure. See Igneous.

Pocket— 1. A small body of ore. 2. A natural underground reservoir of water. 3. A receptacle from which coal, ore or waste is loaded into wagons or cars.

PolingB— Poles used instead of planks for lagging.

Poll-pick— A pick with a head for knocking down rocks already seamed by blasting.

Ponsard furnace — A furnace in which the escaping combustion gases, passing through tubular flues, heat the incoming air continuously through the flue-walls.

Poppet heads- -A timber frame over a shaft to carry the hoisting pulley.

Porphyry— Any massive rock with crystals distinct from the matrix. Typical porphy- ries are however those which have a feldspathlc ground-mass or matrix with a compact or flinty texture and holding disseminated crystals of feldspar. Quartz-porphyry contains a considerable proportion of quartz in addition to the feldspar, and crystals of both minerals are scattered th rough it; but where no such crystals occur and the whole mass Is compact, it forms a variety of felsyte. Porphyry was originally applied to a red syenite with distinct feld- spar crystals from Lpper Egypt, and all similar rocks are still Included among the porphyries.

Porphyritic— Resembling porphyry.

Posl—l. A pillar of coal or ore. 2. An upright timber.

380 Bulletin No. Vi.

Post-andstall—A mode of working coal or iron ore in which so much is left as pillar and so much is taken away, forming rooms and thirling*. The method is called also bordrand-pillar, pillar-and breast* etc,

Post Tertiary Period— Also called Quaternary. The newest of the Ave grand divisions of geological times. It includes the Pleistocene or Post- Pliocene and the Re- cent or Prehistoric systems, which bring us up to the present or historic time.

Pot-holes— Kettles; circular holes sometimes much deeper than wide, worn into the solid rook at falls and strong rapids, by sand, gravel and stones being spun round by the force of the current.

Potstone—K coarse or impure variety of soapstone; so called from being easy to cut into pots owing to its softness.

Power drill-- See Rock-drill.

Precious metals-See Noble metals.

Precipitate— When a substance, held in solution in a liquid, is thrown down in a solid form by the addition of some other substance in solution, the resulting solid is called a precipitate. When a substance held only mechanically in suspension in a liquid settles to the bottom it is called a sediment.

Prill-- A good sized piece of pure ore.

Primary— See Palaeozoic.

Primitive— Hee Archaean.

Primordial— The name given by Barrande to the oldest fosslliferous rocks as developed In Bohemia. It corresponds with the American Taconic and the British lower Cambrian.

Prop— A timber set to carry a roof or other weight acting by compression in the direc- tion of the axis

Prop-cut timbering— Shaft-timbering with cribs kept at the proper distance apart by props.

Prospecting— Searching for new deposits; also preliminary explorations to test the value of lodes or ore-beds.

Prospector— A person engaged in exploring for valuable minerals, or in testing sup- posed discoveries of the same.

Protogene—A variety of granite in which chlorite or talc takes the place of mica; so called by the French, who supposed that it was the first-formed of the gran- ites. The granites of Cornwall, England, which decompose and yield kaolin are of this kind.

Pseudomorph— False form; the name given to crystalline forms of trcom position not proper to such forms. They may be mere casts, occupying cavities from which crystals have been dissolved, or they may have replaced other crystals par- ticle by particle by some slow process.

Pudding-stone— A conglomerate in which the pebbles are rounded. See Breccia.

Puddling— 1. The process of decarburizing cast iron fusion on the hearth of a rever- beratory furnace, lined t fixed or fettled) with ore or other material rich in oxide of Iron. The bath is stirred with a rabble to expose It to the action of the lining and of an air current. The escape of carbonic acid causes it to boll, whence the early name of this method of puddling, viz., boiling. Dry puddling is per- formed on a siliceous hearth, and the conversion is effected rather by the flame than by the reaction of solid or fused materials. As the amount of carbon diminishes the mass becomes fusible and begins to coagulate (come to nature)* after which it is worked together into lumps (puddle-bails, loups) and removed from the furnace to be hammered (shingled) or squeezed in the squeezer, which presses out the cinder, etc., and compacts the mass at welding heat, preparatory to rolling. Silicon and phosphorus are also largely removed by puddling, pass- ing into the cinder. Mechanical puddlers. in which the bath is agitated by rev- olution or by mechanical rabbles* to save hand labor, are used to a limited ex- tent. 2. The term puddling, now applied in metallurgy exclusively to the above process, originally referred to the puddling of clay or clay and charcoal upon the masonry of a furnace hearth to form a lining. Ditches, reservoirs, etc., are puddled with clav to make them water-tight.

Pumice— A very light, porous and vesicular lava which will float on water; a sort of volcanic froth . Its color is generally whitish or light gray.

Pyrites - See Iron Pyrites.

Pyrolusite— Black oxide of manganese; used for making oxygen.

Pyroschists— Bituminous shales which yield hydrocarbon oils and gases on distillation.

Pyroxene— See Augite.

Pyrrhotite-8ee Iron Pyrites.

Quartz— A common mineral occurring In a great variety of forms. It is composed of the elements silicon and oxygen. It crystallizes in the hexagonal system. The transparent colorless variety, which is the purest form, is called rock-crystal. White or milk-quartz Is a very common vein-stone. Gold occurs most fre- quently with quartz, but only a small proportion of quartz veins contain gold. The numerous varieties of quartz maybe classified in three groups: (1) the vitreous, like rock-crystal, rose quartz, amethystine quartz,et.; (2) the chaloe- donlc, like chalcedony, carnellan, agate, flint, etc.; (3) the jaspery, like jasper, bloodstone, 1yd ian stone, etc. Quartzyte— Quartz rock; a rock composed of grains of quartz cemented, or, as it were, fused together by the same substance. Quartzytes are indurated sandstones; they often contain grains of feldspar. Among the Huronlan rocks, great belts of quartzyte occur from lake Huron north and northwestward; also in central Wisconsin and southwestern Minnesota. vrtzose— Containing quartz as a principal ingredient. latemary - See Post Tertiary. jrc, Queere, Owear—A small cavity or fissure. iickr— Applied to a productive ore deposit, as against one that is dead or barren.

Iron Ores Of Minnesota. 381

Quick-lime— When carbonate of lime (limestone) has been thoroughly calcined this re- sults. By the addition of water it forms hydrate of lime, the process being called slaking.

Quicksilver— A common name for mercury; one of the metallic elements, remarkable for its low melting point, being liquid down to 40© Fah. below zero.

Rabble— An Iron bar bent to a right angle at the end.

Race— An artificial canal for conveying water.

Rail-train— A train of rolls for reducing iron piles or steel ingots or blooms to rails.

Rake— A fissure vein crossing the strata.

Random -The direction of a rake-vein.

Range— A chain of mountains or hills; also a belt or strip of country within which cer- tain economic minerals are supposed to occur or run.

Rapper— A lever or hammer at the top of a shaft or inclined plane, for signals from the bottom.

Reamer— A tool for enlarging a bore-hole.

Recent— The present geological time, although it extends back through a vast period of years. All or nearly all existing species of animals have lived throughout the Recent epoch.

Redshortr— Brittle at red heat, caused by an excess of sulphur.

Reduce— 1. To deprive of oxygen. 2. In general, to treat metallurgically for the pro- duction of metal.

Reef— In mining, often applied to quartz veins or veins of any kind; also to solid or fixed rock in general, as opposed to loose materials.

Refractory— Resisting the action of heat and ohemioal reagents; a quality undesirable in iron ores, but desirable In furnace linings, etc.

Resin— Mineral resin; substances allied in composition to the resins of coniferous trees, such as amber.

Reticulated— A net-like arrangement.

Rests— The arrangement at the top and bottom of a pit for supporting the shaft-cage while changing the tubs or cars,

Reverberatory furnace— A furnace in which ores are submitted to the action of flame, without contact with the fuel. The flame enters from the side or end, passes upward over a low wall or bridge, strikes the roof (arch) of the furnace, and is reverberated downward upon the charge.

Rib— The solid ore of a lode; an elongated pillar left to support the hanging-wall in working out a vein.

Ribboned— When the stratification of rocks is very distinct or strongly marked on a small scale, as by contrast of colors, such as may often be seen in gneisses, they are said to be ribboned. When the lines of contrast are on a larger scale they are said to be banded.

Rider— Bee Horse.

Riddle— A box or vessel with a perforated bottom, used by alluvial gold miners for separating out coarse gravel.

RiMcs, Bee Ripples.

Rvtig—A gutter curb around a shaft to catch and conduct away the water.

Ripples -Grooves or bars across sluices for washing gold.

Rtppte-wiarfc— The wavy surf ace of some beds of sandstones and mudstones, produced by gentle movement in shallow water when these rocks were in a soft condition.

Rise or Riser— A shaft or winze excavated upward.

RnasUng—CsAol nation, usually with oxidation. To drive off sulphur and arsenic.

Rob— To extract pillars previously left for support, or, in general, to take out ore or coal from a mine with a view to Immediate product and not to subsequent working.

Roches mouUmnies— Rounded hummocks or bosses of rook like sheeps' backs, smoothed and striated bv glacial action.

Rock— Commonly used to indicate any stony substance occurring in nature, but geolo- gists are obliged to extend its meaning so as to include almost everything which enters into the composition of the earth, even if the material be soft like marl, clay, or sand. Rocks generally consist of mixtures of different minerals, although some, such as limestone, serpentine, quartzyte, etc., are composed almost entirely of one mineral species. See Mineral.

Rock-basin— A depression or basin-like excavation in the solid rock, sometimes of great extent. Nearly all of our numerous lakes, even the largest of them, are en- tirely surrounded bv solid rook, or lie in rock-basins.

Rock-breaker— Usually applied to a class of machines of which Blake's rock-breaker is the type, and In which the rock is crushed between the jaws, both movable, or one fixed and one movable.

Rock crystal— Transparent, colorless quartz.

Rock-drill -A machine for boring in rock, either by percussion, effected by reciprocat- ing motion, or abrasion, effected by rotary motion. Compressed air is the usual motive power, but steam also is used.

Rock-salt— Common salt occurring in nature in solid beds or rock-masses.

RoUey-way—A gangway.

Rolls— Cylinders of iron or steel revolving towards each other, between whioh rock is made to pass in order to crush it. See Roll-train.

Roll-train— The set of plain or grooved rolls through which iron or steel pUes, ingots, blooms or billets are passed, to be rolled Into various shapes.

Rondlc or RondcUe— The crust or scale which forms upon the surface of molten metal in cooling.

Roof— The rock overlying a bed or flat vein.

Rotten-stone -A soft light earthy substance, consisting of silica in fine grains, resulting from the decomposition of siliceous limestone.

Royally— Dues paid to the lessor or landlord of a mine, or to the owner of a patented Invention.

Rullers— The workmen who wheel ore in wheel-barrows underground.

382 Bulletin No. Vi.

Run-steel— Malleable castings.

Rutile—A mineral consisting of oxide of titanium. It is found associated with tltan- iferous iron ores and occasionally in mica-schist, granite, etc.

Saccharoidal— Having the texture of loaf sugar, as fine-grained crystalline limestone or marble. -

Saddle— Au anticlinal in a bed or flat vein.

Safety-cage— A cage with a safety-catch.

Safety-catch— An automat lc device for preventing the fall of a cage in a shaft or of a car on an incline, if the supporting ca'de breaks.

Salamander A mass of solidified material in a furnace hearth; called also a sow and bear

Sand-pump— A cylinder with a valve at the bottom, lowered into a drill-hole from time to time, to take out the accumulated slime resulting from the action of the drill on the rock.

Sandstone— Rock composed of sand, more or less consolidated or cemented together.

Scaffold— An obstruction in a blast furnace above the tuyeres caused by an accumula- tion or shelf of pasty, unreduced materials adhering to the lining.

Scale— 1. The crust of metallic oxide formed by the cooling of hot metals in air. 2. A scale of air is a small portion of air abstracted from the main current.

Scale of Hardness- The relative hardness of minerals is one of their most convenient tests. There are ten degrees See hardness

Scarcement—A -projecting ledge of rock left in a shaft as support for a ladder, or to sup- port pit- work, etc.

Scarfing— Splicing timbers so cut that when joined the resulting piece is not thicker at the joint than elsewhere.

Schist— Crystall I ne foliated rock, splitting into irregular lenticular or wedge-shaped

Elates There are many kinds of schist, such aschloritic, talcoid. dioritic, mica, orn blende, etc. See state and cleavage.

Scoria or Scoriaz— See slag.

Scouring Cinder— A basic slag, which attacks the lining of a shaft-furnace.

Scoonn lode— A lode having no gossan at or near the surface.

Scram- An Irregular, exploratory pit or excavation, not pursued far enough to become a mine

Scraper— A tool for cleaning base-holes.

Seam—1. A stratum or bed of coal or other mineral. 2. A joint, cleft or fissure.

Seat— The floor of a mine.

Section- In geology either a natural or an artificial rock-cut, or the representation of such on paper.

Secular— Relating to an age or vast period of time.

Sediment— Any matter such as mud, sand, etc.. which has settled down from suspen- sion in water. Most stratified or sedimentary rocks have been formed in this way. although some, as certain limestone and dolomites, have been precipita- ted. See precipitate.

Segregation— A process by which mineral matter has been transfused or exuded into veins and openings, especially in crystalline rocks.

Sclenite— Gypsum in transparent crystals. Septum - A dl1

A division or partition, such as those in an Orthoceras. Seguence-iFollowing. succession, coming after, continuation. Sericite A talc-like hydrou** mica (muscovite) occurring in small scales and forming sericitic schist, which is also called talcoid schist and often spoken of by pros-

I >ectors as la 1 cose schist, but this term properly applies to schists composed argely of talc, which are much rarer.

Series— In geology, a group of rocks in a certain order or succession, or a set of beds having something in common . See page 3.

Serpentine -A compact rock, rather soft or sectile, with a conchoidal and splintery fracture and waxy lustre. When powdered has a greasy feel. Capable of a high polish is called marble. Translucent on thin edges. In color, it has various shades of green, generally dark and leek green, often spotted or veined; these are called verd-antique, also brown, red, yellowish, etc. Composed of hydrated silicate of magnesia and a little iron. The name has reference to its colors, suggestive of those of snakes.

Set or Sett -A frame of timber for supporting excavations, or the space included by the same, usually about 8 ft. x8 ft. x 8 ft.

Shaft— A deep pit or hole sunk through earth or rock for the purpose of reaching minerals. Shafts are generally rectangular in cross section, and perpendicular or approximately so. If they underlie far from the perpendicular they are called slopes.

Shaft- furnace— A high furnace, charged at the top and tapped at the bottom.

Shaft-walls— The sides of a shaft.

Shaking-Table— A slightly inclined table to which a lateral shaking motion Is given by means of a small crank or an eccentric. Water is allowed: to flow over them and they are covered with copper plates coated with mercury for the purpose of amalgamating gold or silver. They may also be provided with ripples and used in separating alluvial gold.

Shale— Fissile argillaceous rock, splitting with the bedding as distinguished from slate, which cleaves in parallel planes independent of the bedding. Shales are generally softer than slates. There are many varieties, as ordinary argilla- ceous or clayey shale, bituminous (like the Utlca) shale, arenaceous, ferrugin- ous, calcareous, etc.

Shamblff— Shelves or benches, from one to the other of which successively ore Is thrown in raising ir to the level above or to the surface.

Shell-Marl— A light colored calcareous deposit in the bottoms of small lakes, composed largely of dead fresh water shells, but apparently also to some extent of pre- cipitated carbonate of lime and the hard parts of minute organisms; used for manure.

Iron Ores Of Minnesota. 383

Shift— The time during which one Bet of men works in a mine. There are usually two shifts of 10 hours each in the 24 hours, but when great expedition is required three shifts of 8 hours each may be worked.

Shift-boss— The foreman in charge of a shift of men.

Stuxxd— Ore washed or detached from the vein naturally. See Float-ore.

Shoading or Shading— The process of tracing boulders to the rock from which they came.

Shoot— An inclined wooden spout or slide for sending down ore or rock; also the richest ore-streaks in a vein, which in the profile of the vein may run at any angle to the horizon. '

Shooting Needle— A sharp metal rod, to form a vent-hole through the tamping to the blasting charge.

ShuU— See chute.

Sickening of Quicksilver— See Flouring.

Silica- Siiex. The same in composition as quartz; used more frequently In chemical language for this substance.

SfWcous— Relating to silica.

Silicifled— Made into silica. Organic remains, both plant and animal, are often thus converted.

Siil—1. A stratum. 2. A piece of wood laid across a drift to constitute a frame with the jposts, and to carry the track of the tram-way.

Sill— Mud, fine sand, etc., deposited in harbors, estuaries, lagoons, etc., from the slack- ing of the currents which had borne them along.

Silurian System— The th.rd system, in ascending order, of the Palaeozoic period.

Sink-hole* - When rocks, such as salt, gypsum or limestone have been locally dissolved away, the earth may sink and form a cup-shaped basin, to which this name is given.

Sinking-fire— A forge in which wrought iron scraps or refined pig iron is partially melted or we'ded together by a charcoal blast.

Sinuous— Curving, winding.

Skep or Skip— An iron box working between guides, in which ore or rock is hoisted. It is distinguished from a kibble, which hangs free In the shaft.

Skid— A wooden beam, scantling or other timber used in sliding heavy weights upon.

Skimping— See Jigging.

Skull- A crust of solidified steel lining a Bessemer ladle.

Slab— A wide flat stone; the outside cut off a log of wood in sawing it into planks.

Slag— The vitreous mass, separated from the fused metals in smelting ores.

Slickensides— Polished and sometimes striated surfaces on the walls of a vein or ore- deposit, or on the interior joints of the vein material or of rock masses. They are the result of movement.

Slide— An upright rail fixed in a shaft, with corresponding grooves for steadying the cages. 2. See Fault, Dlslrtcation.

Sitae— Natural transverse cleavage of rock.

Slip— A vertical dislocation of the rocks.

Slipes— Sledge runners, upon which a skip is dragged from the working breast to the tramway.

Slit— A communication between two levels.

Slope— See Incline.

Sluice-Box— A long trough or flume with ripples for catching alluvial gold when the earth is washed down it by water.

Sludge— Is the pumplngs lifted from a churn drill, the product of the cuttings of the drill.

Smelting - Reducing ores by fusion in furnaces.

Smift— A fuse or slow match.

Snoff—A short candle-end put under a fuse to light it.

Sole—1. The bottom of a level. 2. The bottom of a reverberatory furnace.

Solid crib-timbering -ShB.(t-tlmber\na; with cribs laid solidly upon one another.

SoUar—A platform in a shaft, usually constituting a landing between two ladders.

Sough— See Adit.

Sow 1. See Salamander. 2. See Pig-iron.

Spall or Spawl— To break ore. Ragging and cobbing are respectively coarser and finer breaking than spalling, but the terms are often used interchangeably. Pieces of ore thus broken are called spall*.

Spar— A name given by miners to any earthly mineral having a distinct cleavable structure and some lustre: with Cornish miners generally quartz.

Specific Gravity— In regard to solids, means their weight relatively to an equal bulk of water at a temperature of 60° Fahr.

Specimen— Properly speaking, a sample of anything; but among miners it is often re- stricted to selected or handsome minerals, as fine pieces of ore, crystals, or pieces of quartz containing visible gold.

Specular— Mi rror-1 Ike, as specular iron ore. a variety of hematite.

Spend— To break ground; to continue working.

Spteqcleisen— Manganiferous, white cast-iron.

Spiking-curb—A curb to the inside c f which plank-tubing is spiked.

Spilling— A process of driving or sinking through very loose ground.

Spills— Long thick laths or poles driven ahead horizontally around the door-frames in running levels in loose ground— a kind of lagging put in ahead of the main tim- bering.

Spire— The tube carrying the train to the charge in a blast hole. Also called reed or rush* because these as well as spires of grass are used for that purpose.

Splil— To divide a ventilating current.

Sponge— Metal in a porous form, usually obtained by reduction without fusion.

Sprag—l. A prop. 2. A short round piece of wood used to block the wheels of a car.

Spreader— A horizontal timber below the cap of a set, to stiffen the legs, and to support the brattice when there are two air-courses in the same gangway.

384 Bulletin No. Vi.

Spreaders— Pieces of timber stretched across a shaft as a temporary support of the walls.

Sprue— A piece of metal attached to a casting, occupying the gate or passage through which the metal was poured.

Spud— A nail, resembling a horse-shoe nail, with a hole in the head, driven into mine- timbering, or into a wooden plug inserted in the rock, to mark a surveying station.

Spur— A branch leaving a vein, but not returning to it.

Square sets— A kind of timbering used in large spaces.

Squeeze— The setting, without breaking, of the roof over a large area of workings.

Squeezer— A. machine for reducing the puddle ball to a compact mass, ready for the hammer or rolls,

Squip—A slow-match or safety-fuse used with a barrel.

Stack— A chimney.

StalactUe8 -Tapering, or icicle-shaped projections of travertine hanging from the roofs of caves or fissures, formed by the dripping of lime water.

Stalagmites— Ot the same composition and form as stalactites, but have grown upward from floors of oaves, etc., on which lime-water has dripped.

Stamper Box— See Mortar Box,

Stamp Head A heavy and nearly cylindrical cast iron head fixed on the lower end of the stamp rod, shank or lifter to give weight in stamping the ore. The lower surface of the stamp head is generally protected by a cheese-shaped "shoe" of harder iron or steel which may be removed when worn out. These shoes work upon "dies" of the same form laid in the bottom of the mortar or stamper box.

Stamp Mill— A mill for stamping ores; used for reducing those of gold, silver, tin, cop- per, etc.

Stamps— The pieces into which the rough bars shingled from the finery ball are broken, to be pUed for subsequent rolling into sheet-iron.

Stanniferous— Carrying tin.

Steatite— Or soapstone; a massive1 variety of talc: a very soft rock having a soapy or greasy feel; it is a silicate of magnesia with a little water.

Steel— A compound or alloy of iron, principally with carbon, which may be cast, forged, hardened and tempered. Ordinary steel contains from 0.5 to 1.5 per cent of carbon. More carbon makes cast iron; less carbon, wrought-iron. But this classification is not now strictly adequate or applicable, either to the sci- entific or to the commercial use of the term. The so-called mild or loir or structural steels (low in carbon and hence relatively soft and tough as compared with high or hard or tool steels, do not always harden or temper. An interna- tional committee appointed by the American Institute of Mining Engineers has recommended the use of the following classification:

1. That all malleable compounds of iron with its ordinary ingredients, which are aggregated from pasty masses, or from piles, or from any forms of iron not in a Aula state, and which will not sensibly harden and temper, and which generally resemble what is called "wrought iron," shall be called weld-iron.

2. That such compounds when they will from any cause harden and temper, and which resemble what is now called puddled steel, shall be oalied weld-steel.

3. That all compounds of iron with its ordinary ingredients, and which will not sensibly harden by being quenched in water while at red-heat, shall be called ingot-iron.

4. That all such compounds, when they will from any cause so harden, shall be called ingot-steel..

This proposed classification does not cover ordinary cast or pig iron. It is a classification of the malleable compounds only. The Institute has recom- mended its use in papers and discussions, except as to the term weld, for which a substitute was desired, and meantime the continuance of the old term wrought. though in a somewhat wider significance, was suggested. The resolution of the Institute concludes as follows: "It being understood that the ingot-iron and ingot-steel of this classification constitute, taken together, what is now commer- cially known as cast-steel, including the so-called low or soft cast-steels." Bes- semer steel is made by de-carburizing oast iron in a converter. (See Bessemer Pro- cess). Blister or cement-steel is made by carburizlng wrought iron bars by packing them in charcoal powder and heating without access of air. It is melted in crucibles to cast steel, or hammered (tilted) to shear-steel (for cutlery, etc.), or rolled to spring steel. Puddled steel is made by arresting the puddling pro- cess before wrought iron has been produced, and thus retaining enough carbon in the bath to constitute steel. Natural steel is a similar product, obtained from the refining of cast-iron. Crucible cast steel is steel made by the fusion in crucibles, either of blister-steel or puddled-steel or steel scrap, or other Ingredi- ents and fluxes which will produce the desired quality. Cast-steel in its widest sense, as now employed, comprises all malleable compounds produced by fusion, including, therefore, the Bessemer and open-hearth metal. Open hearth, called also Martin-Siemens steel, is made in the reverberatory furnace, (almost invariably a gas-furnace on the Siemens regenerative system, since an intense temperature is required) by the reaction, in the fused bath, of oast-iron, with wrought iron, iron-oxide or iron ore. At a certain stage of the process & deoxidiz- ing or recarburizing agent (spiegeleteen, ferromanganese) is added. Chrome-steel is a crucible cast-steel in which chromium is a constituent. Tungsten or Wolfram- steel is a steel containing tungsten. Phosphorus-steel is a steel in which the amount of phosphorus exceeds that of carbon. Damascus-steelAs a laminated mixture of steel and wrought-iron. India-steel or wootz is manufactured in India direct from the ore.

Stemming— The tamping put above the charge in a bore-hole.

Stempel or Stempte— 1. ne of the cross-bars of wood placed in a mine-shaft to serve as steps. 2. A stull-piece. 3. A cap, both sides of which are hitched instead of be- ing supported upon legs.

Iron Ores Of Minnesota.

Slip-pefn-A vain alternately cutting through the strata of country-rock a

parallel with them. StticH-worfc— An ore-doposl t of such form

be a solid muss of ore, or a mok-maMM so 11

that the whole must be mined together.

StV'IC-t I!, I ii,,-1.; tli-i I in -inking ii shaft.

Stape— ToevaeiiiUt'iiroliui vi-ri.ii-:il ..r liUhlv In.'lnii'.l . ii-p. -it by driving horizontally

upon It- a suriis ivni k in--, i.rn jiiiiut.-i.liiiri-iv nviT ilr-s other of via vena. Each

liiii'i/oniiil "fi'lJu.- is fin li-tl ii slope .jiciilinlilv :i ..irruption of ttep) because

' tbo noit above or liH.uv. i in- faiv under ft Jack assumes the

-1i:j|H' nf :i (lir-'lit nf <(.i i rs. WIivil I lie lir-t -Ii.'|ji3

" — -j) he removed, rind uf — " ucnced above It, Bod at sKipn bet ins at un ii uirtltr-liumi etuplnu.

iii'i i i eninriiein -ni h I ii i vc it. inii'l si i mi. tin- prui.v— is called oner-hand itoping

Win- 1 1 I liv iirsi smiic lie, In-- ni :in iiijmii- m.t. lie succeeding ones are be

-f ext-ppt .that .which incidentally performed lu

i etc., for JMpnmgrM 'if opening a mine.

Sloping When ;i mine lin.s i|i ' tjv- siuklir.' i Litis and driving levels (called

simply "sin kin-- find ili-iiiim"! ilm uovt jn- is to stopaout the ore, which .uTi-isi- iii f\i;;ivui in!; i i villi. -r niMv.ii.i fi-iim i in- rue r of each level, called over- hiirnl siriiiiic-. ..[ iLi.ivuiviis.l iviiru i In; 'l. i r-. .-ni;.-.i n iniorhand stoplng. The lat- ter requires all the material to be removed out of the mine, whereas by the overhand process the refuse maybe left supported on stulls or flooring made of

Stopping— 1. See Stnpiiig. 2. A partition of boards, masonry or rubbish, to stop the alr-

eh all the material Is removed, and the waste la

Its delineation o

Stratum-- A bed or layer of rook; strata, more than one layer.

Streak— Tha color of a mineral when scratched. When a mineral Is rubbed on a surface of unglazed porcelain the streak Is well brought out.

Sb-fn— Fine parallel lines, either grooves or ridges.

.Striated-. Marked with parallel grooves or strloj.

Strike — Tke course or bearing of the outcropping edges of Inclined atrata In reference to the horizon, or la other words, the strike 1b the Intersection of the plane of the bedding with the horizontal plane. It Is therefore at right angles to the dip.

Slrlno— A very small vein, either Independent or occurring as a dropper or branch of a

Strip— To remove the overlying earth and disintegrated rook from an ore-deposit.

Structure— The arrangement of rock-masses, such as their being bedded. Jointed, slaty, schistose, basaltic, columnar, etc.; also the attitude of rocks and their positions relatively to each other.

Studdles— Props supporting the middle of dull*.

Stuli— A platform Btull-ooverlng) laid on timbers 1st ull- pi aces) braced across a work- ing from side to side, w support workmen or to carry ore or waste.

Siulm--5eo Adit .

HubUmaUoH— The volatilization and condensation of a solid substance, without fusion

Sublimation Ouwry-Tbe theory that a vein was Ailed first with metallic vapors.

SuLtidenct— A sinking down of a part of the earth's crust.

Sulphur— 1. Iron pyrite. 2. Carburetted or sulphuretted hydrogen. In vsrburetted hydrogen there is no sulphur.

Sulpoureii— The undecompoeed metallic ores, usually sulphides.

Sump— The apace left below the lowest landing In a shaft to collect the mine water. The lowest pumj- "

Supe., , „

aeter. In Canada tbey Include the fieistoceue i

deposits.

Superpostoon— The order In which rocks are placed above one another.

Surfnoe (Jeukvu -The geology of the superficial deposits and uf the surface of the

fundamental rocks. Bwab-— A stick frayed out atone end; used for cleaning the sludge out of holes In

process of being bored for blasting. Si/enlU— Originally applied toe reddish crystalline granitoid rock from Syene in Egypt,

consisting of feldspar, hornblende and ciuartt, now culled ouartE-syenlte, while

syenite has come to mean a crystalllue granitoid rook consisting of orthoelase

feldspar and hornblende with --

Ull— When s "' '

arrange mei

When stratified rock) dip from opposite aides towards a common line the

Jt series Of strata having Nome general character In commt division of the rocksof the earth's crust, the system ranks next u formation In comprehensiveness. Formations art somewhat local dlvi

many of them can only be recogulred in one country, whereas the svi sufficiently comprehensive to be recognized In all parts of the world, ine nys tenia In ascending order are Laureutlam Ontarian. Taconlc. Cambrian, Silu- rian. Devonian. Carboniferous, Permian, Trlasslc, Jurassic, Cretaceous, Eocene

Indiass, rope and kibble.

386 Bulletin No. Vi.

Taconic— The Taconic system is that series of rooks containing the primordial fauna at least that portion which is older than the New York Potsdam. It is the Lower Cambrian of English geologists, and the Huron! an of the typical Huronian area of the Canadian geologists. Named from the Taconic mountains of west- ern New England, by Dr. E. Emmons, it antedates, as a primordial system, both Cambrian and Huronian. It is the principal iron ore-bearing system of the lake Superior region, and in this Bulletin is substituted for the term Huronian be- ing" of earlier date and less ambiguous. '

Tailings— The fine waste material from jiggers and crushing mills. That from the latter is carried out by water and is as flue as sand.

Tail-race -The channel for carrying off the spent water of a mill or from a washing process.

Talc— A very soft mineral, being 1 in the scale of hardness; occurs in laminse like mica but is not elastic; has a pearly luster and greasy feel; prevailing color, green- ish; isa silicate of magnesia; enters into the composition of talcose schist, soap- stone or steatite, the variety of granite known as protogsne, etc.: is used in the manufacture of crayons, crucibles and porcelain.

Talcoi d— Resembling talc, as talcoid schist. See Scrtcite.

Talcose— Containing talc; aspotstone, steatite and talcose schist.

Talcose Granite— See Protogene.

Talus- In geology, the sloping mass of fallen rocks accumulated at the base of a cliff or precipice.

Tamp -To fill (usually with clay tamping) the bore-hole or other opening through which an explosive charge has been introduced for blasting.

Tamping— The crushed rock or other material which is hammered tightly down over the explosive in a drill-hole for blasting.

Tamping Bar— An iron bar, shod with copper to obviate striking fire, used for driving down the tamping.

Tap cinder— The cinder drawn from a puddling furnace or bloomary.

Tap-hole— The opening through which the molten metal is tapped or drawn from a fur- nace.

Tar— Soft pitch or thickened petroleum, found in cavities of some limestones, as those of the Cornlferous formation in Ohio, also In those of the township of Keppel west of Owen Sound. Along some parts of the Athabasca river, in the North- west territory, much mineral tar has exuded from the rocks. Common in oil districts.

Teem—1. To dump. 2. To pour steel from a melting-pot

Terra Cotta— Ihe ': baked earth" of the Italians, Kiln-burnt clay assuming a peculiar reddish-brown color fashioned into vase3, statuettes and other mouldings.

Terra Sienna— See Ochre.

Terrace— A nearly level shelf of land abutting on higher ground and dropping off sud- denly on the lower side. This steep bank is due to the former wearing action of some body of water which cut it away.

Terrane—A group of strata, a zone, or a series of rocks. This word is used in the description of rockb in a general, provisional or non-committal sense.

Tertiary Period or Age— Also called the Cainozoic. The third grand division of geological time above the Azoic or the fourth in all. It comprises (in ascending order) the Eocene, Miocene and Pliocene systems.

Tessellated— A surface divided in squares, or figures approaching squares, by joints or natural divisions.

Texture The coarseness or fineness, character, arrangement, etc., of the component grains or particles of a rock.

Thermo-aqueous— Produced by, or related to, the action of heated waters.

ThUl— The floor of a mine.

Thread— An extremely small vein, even thinner than a string.

Tlirow— A dislocation or fault of a vein or stratum which h&aoeeuthrownup or down by the movement.

Thrust— The breaking down or the slow descent of the roof of a gangway. See creep.

Thurl— To cut through from one working to another.

Thurlings or thirlings— Passages cut from room to room in post-and-stall working.

Thurst— The ruins of the fallen roof, after pillars and stalls have been removed.

Tiek-tuile— See Vug.

l\tt— The Scotch name for hard-pan, boulder-clay, or the unstratlfled stony clays of the drift formation; a convenient term now generally adopted by geologists for these deposits.

Titaniferous— Carrying titanium, as titaniferous ore.

Titanic— See llmenite.

Titanite— Or sphene ; a mineral consisting of silicate of titanium and lime, generally darkly colored, occurring among later crystalline rocks.

Tilt-hammer— A hammer for shingling or forging iron, arranged as a lever of the first or third order, and '-tilted or "tripped" by means of a cam or cog-gearing, and al- lowed to fail upon the billet, bloom or bar.

Toadstone— A kind of trap rock.

Top-wall - See hanging-wall.

Tourmaline -A mineral occurring in long, usually striated prisms In the ancient crys- talline rocks; generally dark in color, harder than quartz and complex in coni- f>ositlon, but consisting principally of silicate and borate of alumina with some ron, n.agnesia. lime, fluorine and different alkalies.

Trachyte— A volcanic rock or lava common in Tertiary and Post-Tertiary times, con- sisting principally of a glassy variety of orthoclase called sanidine and some triclinic feldspar, together with hornblende, mica, magnetite, etc. It lscharac terized by its rough fracture.

Tram— 1. A four-wheeled truck to carry a tub. corve or hutch, or to carry coal or ore on a railroad. 2. One of the rails of a tram road or railroad.

Transition— Intermediate. A term i sed by the older geologists for rocks which came between their better defined divisions; but little used at present.

Iron Ores Of Minne80Ta. 387

Translucent— Admitting the passage of light, as milk-quartz, but not capable of being seen through.

Transparent- That may be seen through, as rook-crystal, Iceland-spar, selenite. etc.

Trap -A general term for igneous rocks, such as the greenstones, basalts, amygdaloids, Rome porphyries, etc., but too indefinite for modern geological language.

Tremolite—A variety of hornblende in radiating or columnar aggregates, generally light colored, with pearly lustre.

Triassic System— The first or lowest system of the Mesozoic or secondary period.

TrUobiten-A family of crustaceans, so named from their bodies as viewed from above being divided longitudinally into three lobes. They embrace many genera and species; are most abundant in the Taconic and Cambrian systems, dying out in tne Carboniferous; so that rocks in which the remains of these oreatures are common may be pronounced to be below the coal bearing strata.

Tributer— One who works a mine or mineral deposit for a share of the product.

Truncated— Cut or broken off abruptly.

TroUy—A small two or four-wheeled truck without a body.

Trouble— A dislocation of the strata.

Trt/ugh— In geology, synonymous with Basin and Synclinal, which see.

Truck— A small tram-car for carrying coal, rock or ore along a level in a mine, or out to a shoot or a dump. Also goods paid instead of money for wages.

Tubbing— A shaft lining of casks or of cylindrical caissons, of iron or wood.

Tubing— Lining a deep bore-hole by driving down iron tubes.

Tufa— Any open, porous or vesicular mass, as volcanic tufa, calcareous tufa, etc.

Tug— The ironTiook of a hoisting bucket, to which the tacrtles are attached.

Tunnel — 1. A nearly horizontal underground passage, open at both ends to day. 2. See Adit.

Tunnel-head— The top of a shaft-furnace.

Turn— A pit sunk in a drift.

Turn-bat— A wooden stick used in turning the tongs which hold a bloom under the hammer.

TurUe-stones— Large nodular concretions found in certain clays and marls. In form they have a rough resemblance to turtles, and this appearance is increased by their being divided into angular compartments by cracks filled with spar.remind- ing one of the plates on the shell of a turtle. They are common in the Cretaceous marls of the western states and territories.

Tuyere, Tweer, Twyer, T were— A pipe inserted in the wall of a furnace, through which the blast is forced into the furnace. Usually the tuyere enters through an embrasure in the masonry (tuyere-arch). A nozzle or Interior pipe is frequently inserted at the inner end or the tuyere. By changing the nozzle, the size of the opening for the blast may be thus regulated without changing the tuyere. The latter is either an annular hollow casting of iron (box-tuyere) or bronze, fyronze- tuyere\ or a coll of iron pipe. In either case water is continually circulated through it to protect it and the nozzle from the action of the melting materials In the furnace. 8pray-tuyeres are open box-tuyeres in which a spray of water in- stead of a current, is employed. This is vaporized by the heat, and passes away as steam.

Tuyere-Plate— See Bloomary.

Tymp—A hollow iron casting, cooled interiorly by a current of water, and placed to protect the tump-arch, or arch over the dam in a blast furnace having a fore- hearth. (8ee Open front.)

Unconformable— See Conformable.

Unctuous— A greasy feel such as that of soapstone, powdered serpentine, certain clays, etc.

Under-hand— See Stope.

Underlie or Underlay— The departure of a vein or stratum from the vertical, usually measured in horizontal feet per fathom of inclined depth. Thus a dip of 60 o is an underlay of three feet per fathom. The underlay expressed in feet per fathom is six times the natural cosine of the angle of dip. See Dip.

Undisturbed— Rocks which lie in the positions In which they were originally formed. See Disturbed.

Univalve— A moll us k having a single shell. A bivalve moll us k has two shells.

Unstratijled— Rocks which are not in beds or strata, as granite, syenite, greenstone, etc.

Unwater— To drain or pump water from a mine.

Upcast— i. The lifting of a coal seam or ore bed by a dyke. 2. The opening through which the ventilating current passes out of a mine. See Downcast.

Upheaval— A lifting up. as if by some force from below, of stratified or other rocks.

Upthrow— An upward displacement of rook along a line of break or fissure.

Vamping— The debris of a stope, which forms a hard mass under the feet of the miner.

Vein— A fissure, a contact-space, or a gash which has been filled with mineral matter. After a rent or fissure has been formed In solid rock, there is usually some dis- location, so that a space is left between the walls. This gives rise to the fissure vein. Similarly a movement or dislocation along the contact of two different kinds of rocks gives rise to the contact vein. A gash vein terminates in a thin edge In all directions or has a lenticular form, and is only exposed so that it may be discovered by a natural section of the rock formed either by the sur- face of the ground or by a cliff.

Veinstone— The mineral matter filling a vein, exclusive of the ore. See Oangue.

Veined— Marked or streaked with veins or lines of color in various directions, as some marbles.

-antique Mafl)le—A variety of green serpentino with patches and veins of white oalcspar and capable of a fine polish.

Verifier— A tool used in deep boring for detaching and bringing to the surface portions of the wall of the bore-hole at any desired depth. „

383 Bulletin Notvi.

Vermilion— The lowest of the stratified schists; [the crystalline schists. Dr. Lawson named them Coutchiching.

Vermilion— A bright red pigment consisting of the sulphide of mercury. See Cinnabar.

Vertebra— A joint of the backbone of any vertebrate animal.

Vertebrata— One of the provinces or primary divisions of the animal kingdom.

Vesicular—Containing little bladder-like cavities, such as some lavas.

VUreous— Like glass.

Vitrify— To make like 'glass.

Volcanic— Pertaining to volcanoes. Volcanic rocks are those of igneous origin formed at or near the surface, such as lava, amygdaloid and volcanic ash ; whereas igneous rooks formed at a depth and under pressure are generally crystalline and are called plutonic. See Igneous.

Vug% Vugg or Vugh—A cavity in the rock or ore, usually with a crystalline incrusta- tion.

Wad-hook— A. tool with two spiral steel-blades for removing fragments from the bottom of deep Dore-holes.

WaU—1. The side of a level or drift. 2. The country-rock bounding a vein laterally.

WaXL-plate*— The two side-pieces of a timber frame in a shaft, parallel to the strike of the lode when the shaft is sunk on the lode. The other two pieces are the end- pieces.

Waste— Old workings. The signification seems to include that of both goaf and gob.

Weather-door— A door in a level to regulate the ventilating current.

Weathering— Oh&ng\ng under the effect of continued exposure to atmospheric agencies.

Wedgina-curb or Wedging-crib—A curb used to make a water-tight packing between the tubbing in a shaft and the rock-walls, by means of split cats, moss and wedges, driven in between the curb and the rock.

Weld— To join pieces of metal by pressure, at a temperature below that of complete fusion.

Whim— A lare drum for winding rope, revolving horizontally and kept in its place by a frame- work. It is worked by a horse or horses attached to a long horizontal beam placed under the drum.

Whin or Whinstone— Basaltic rock; any hard, unstratified rook; greenstone.

Whip— A beam over a shaft, with a pulley and rope for raisins or lowering a bucket or kibble. This is done by means of a horse going forward and back again.

Win— To extract ore.

Winch or Windlass— A man-power hoisting machine, consisting of a horizontal drum with crank handles.

Winding- Hoisting with a rope and drum.

Winds— See Winze.

Winning A new opening.

Winze— An interior shaft, usually connecting two levels.

Work— Ore not yet dressed.

Working home— Working toward the main shaft in extracting ore or coal, as in longwaU retreating.

Working out— Working away from the main shaft in extracting ore, as in longwaU ad- vancing.