Stanford clay deposit, Latah County, Idaho
The Stanford clay deposit, Latah County, Idaho, is about 4 miles northwest of Deary, Idaho. During World War II, the area was studied by the U. S.
Public-domain full text preserved in the Mountain Man Mining Library. Original source: pubs.usgs.gov.
UITI TED SrT2`, 11.3 CF INTERIOR GEOLOGICAL SURVEY STANFORD CLAY DEPOSIT, LATAH COUNTY, IDAHO By Vernon E. Sc:leid, Jc-f= Hosterman, and I. G. Sohn ,0,,ot2sLALso„, 5 2 9 2 9 , U. S. Geological Survey OPEN FILE REPORT This report preliminary and has not been revi 'wed for conformiv w_th GeiogiLal Survey standards or nomenclature. swOMmi 64.1.a 76GICAL Suel;>y., r ///$. sH1NG ToN APR 26 1954
May 1951
CONTENTS Page Abstract Introduction Purpose and location Field work and acknowledgments Gcolo,_T Rej_onal geology Geoloy of the Stamford clay deposit Granitic residual clay Basaltic residual clay Transported clay Ceramic data Clay deposit General features Conclusion Bibliography. Appendix: Drill hole logs and assays ILLUSTRATIONS Plate 1. Geologic and index map of Latah County, Idaho clay district In envelope 2. Ma:0 showing areal anc"._ economic geology of the Stanford clay deposit, Latab County, Idaho In envelope
Abstract The Stanford clay deposit, Latah County, Idaho, is about 4 miles . northwest of Deary, Idaho. During World War II, the area was studied by the U. S. Geoloical Survey in c000eration with the U. S. Bureau. of Mines. The Bureau of Mines hand-augered 10 holes and made chemical analyses on the samples for available alumina and available ferric oxide, and also measured the ignition loss. The deposit contains three types of clay: granitic residual clay derived from the weathering of Cretaceous granodiorite in place; basaltic residual clay derived from the weatherinc of Tertiary Columbia River basalts in place; and transoorted clays of the Latah formation derived from the weathered debris of the granodiorite and older rocks. Only the transported clays are considered as a potential source of available alumina and ceramic-grade clay in the Stanford denosit. The Stanford deposit averages 24.8 percent available alumina and 2 percent available ferric oxide. Transported clays containing more than 15 percent available alumina and less than 5 --)ercent available ferric oxide would be suitable for many ceramic products and some may meet the requirements of high-heat or super-heat duties. Therefore, the clays are usable for ceramic struc tural ware such as bricks, terra cotta, and drain tile.
INTRODUCTION Purpose and Location During World War II, the U. S. Geological Survey, in cooperation with the U. S. Bureau of Mines, made an appraisal of the national alumina resources in an attempt to Emarantee an adequate supply of aluminum. T'is report is a part of a study of hi-h-alumina clay resources in the Pacific Northwest region, rnd describes the results of the investigation of a deposit high-alumina clay 4 miles northwest of Deary, Latah County, If'--.ho. The Stanford clay deposit is secs. 7, 2, 3, 4, 9, 10, 11, and 12, T. 2 0 7., P. 3 W., and secs. 6 and 7, T. LO 77., P. 2 W., Boise Meridian, Latah County, Idaho (pl. 1). State _highway /42, all all-weather road, crosses the deposit, and the Washington, Idaho, and Montana Rail road has a station at Stanford. Power is available from a 22,000-volt transmission line of the Washington Water Power Co. The deposit is in a part of the Columbia River P7atec,--3-1 _thysiocra,)hic province that is characterized by broad, gently rounded hills and fairly broad, even-floored valleys. The area is drained by the Big Bear Cree-_:. anc its tributaries.
Field Work and Acknowledgments The senior author examined and sampled some of the clay outcrops in the Stanford area Curinc. the summer of 1938, as 1-)art of a study of clay in northern ICElio for the Idaho 19ureau of Mines and Geolo7y. An explora— tory drilling --)program was conducted in the summer of 19L3 by the U. S. Bureau of Mines, under the siroervision of S. H. Lorain, District Engineer, and Mire :ahelich, Project Engineer. Ten hand auger holes were drilled totaling 187.7 feet and chemical assays were made on samples re-Jresenting 99.3 feet. In cooperation with the U. S. 2ureau of Ydnes, the U. S. Geological Survey supervised the drill hole logging and the geologic studies of the deposit. I. G. Sohn magoed the geology of the area during the summer and fall of 1944. The authors are indebted to Mr. Lorain and Mr. Mihelich, U. S. 71-Ireau of Mines, for the many courtesies extended and for the chemical data they made available. The writers are indebted to the University of Idaho for use of office space r:aile preparin,_ portions of the report.
GEOLGGY Regional Geology The high—alumina clays of Latah County, Idaho, and adjacent areas are divisible into three types: residual clay derived by weat:-Ieri7) of r-a-anitic rocks, residual clay derived by weathering of basaltic rocks, and transported clay. The trans)orted clays are derived )rimarily from gran— itic residual clays that have been transported and deposited in water with other materials to form the Latah formation. An understanding of the clay deposits is best obtained by a brief summaTy of the regional geology (pl. I). The Belt series of pre—Cambrian Plate 1. Geologic and index map of Latah County, Idaho, clay district. age, consisting of quartzites, mica schists, and minor amounts of gneisses, form the mountainous country to the east and north of the clay district. Locally the eroded surface of the Belt rocks, a series of volcanic flows, was extruded in Permian(?) time. Two types of volcanic rocks are recog— nized at the largest outcrop in the vicinity of Potato Hill; one type consists of pink, gray, and dark purple porphyritic lavas varying in com— position from rhyolitc to dacite; the second type is a dark purple to black quartz—bearing flow breccia. In late Jurassic or early Cretaceous time, the older rocks were cut by large masses of a,Tanodiorite and related igneous rocks that are tentatively considered to be part of the Idaho batholith. The ty-.)ical granodiorite is light gray, medium -:rained, and Eranular with gneissoid and porDhz-ritic textures locally; its chief minerals are quartz, biotite, and both -ootash and soda—lime feldspars. The related
igneous rocks consist of hornblende syenite rt Gold Hill (pl. 1) and minor amounts of ada,-.elite, tonalite, and granite with small pegma tite, aplite, and lamDrophyre dues. Post-intrusion erosion exposed the granitic rocks, and a mature topography developed. Beginning in Miocene time, the Columbia River basalts were extruded (Pardee and Bryan, 1926, D. 11-12). These basalts are core_ ,osed of plagio clase and augite in a glassy groundmass with minor amounts of ilmenite and olivine. Streams dammed by lavas formed lakes in which the Latah formation was deposited (Pardee and Bryan, 1926, D. 8). Thus the Latah formation is interbedded with and contemporaneous with the basalt. During a protracted lull in the extrusion of basalt, a weathering surface developed i_l eastern Washington and northwestern Idaho. This weathering surface, which divides the upper basalts from the lower basalts, was given the name Excelsior surface (Scheid, 1946, p. 19). During the Excelsior interval, the climate was very warm and humid, with conditions that -emitted complete oxidation and the formation of the residual clews. The greatest thickness of residual clays was formed upon a land surface of low to -lederate relief. The results of other intraflow weathering intervals have been observed, but none approaches the 124-foot maximum depth of weathering or the lateral extent of the Excelsior surface (Scheid, 1947, D. 1224). From drill hole evidence the Excelsior surface is known to be a gently undulating surface beneath the hills and does not rise far above the present valley floors. Renewed extrusion of basalt brought the Excelsior weathering interval to an end. The upper Latah formation was deposited upon the granitic and basaltic residual
clays in lakes that were formed by streams dammed )ost—Excelsior basalt flows. This me:lber contains the nrincipal transported clay de— posits, and is now thickest beneath the hills. The Latah formation is composed of lacustrine and stream deposits of interbedded claz7s, sand, and gravels that were derived primarily from the granitic and metamorpl-Ac rocks of the mountainous areas. By Pleistocene time, the land surface was maturely dissected in the highlands of older rocks and youthfully dissected in the plateau ,7seas of the basalts. The region was then irregularly blanleeted by the Palouse formation, wi:ich is com)osed for the most part of wind—blown silt from the west (Bryan, 1927, p. 41). The original deposition of she loess material was thickest on the lee sides of the hills. Sub— sequent erosion has removed more material from the valleys than from the hills so that the formation is now thicker on the hills than in the valleys. Terrace deposits of late Pleistocene age and alluvium of recent age are fount. in the valleys of the major streams. The materials of these deposits resemble and blend with the Pelo,Ise formation, so that these deposits have been mapped on the basis of topography.
Geology of the Stanford Clay Deposit The Stanford clay deposit occurs in the northwestern corner of the Avon embayment (pl. 1), a relatively flat area underlain by Columbia River basalts and sediments of the Latah formation and. part1:- surrounded by hills of older rocks. To the east, the embayment is limited by Potato Hill tha..t is underlain by Permir,,n(?) volcaaics; to the northeast and west, it is limited by granodiorite hills; and to the north it is limited by hills underlain by the Belt series. The regional distribution of these rocks is shown on plate 1, d the local distribution is shown on - late 2. Plate 2. Map ei-Lowing areal and economic geology of the Stanford clay deposit, Latah County, Idaho. Rocks of the Belt series do not occur within the area of detailed mapping (n1. 2), out crop out about a mile north of the deposit. These rocks have contributed very little except quartz and muscovite to the sedimentary beds of the Latah formation. The Permian(?) volcanic rocks, also, are not exposed in the area cf detailed mapping and they have probably contributed very little to the sedimentary beds of the Latah formation. The granodiorite and related igneous rocks are well exposed in the western portion of the de-posit (pl. 2). The weatherinc and decomposition of these rocks supplied practically all of the kaolinite for the trans— ported clay beds of the deposit. The contact of the granodiorite with the overlying basalt (p1. 2) is concealed beneath the Latah formation and/ or the Palouse formation.
The Columbia River basalts form the floor of the major portion of the Avon embayment. The upper basalts ca=nnot be distinguished from the lower basalts where the Excelsior surface is rot exposed, or where there is no upper Latah formation dividing them. On ,late 2, ..)wevcr, both the upper and lower members of the Columbia River basalt are sown because they occur at different altitudes and the Latah formation lies between them. The lower Latah member occurs as minor lenses within the lower Columbia River basalt and does not crop out within the ma)ped area (21. 2). The upper Latah formation was deposited upon the Excelsior surface and occurs throughout the map-)ed area, but rarely crops out. The Palouse formation forms the bulk of the over-burden La the denosit area. The greatest thickness of this formation encountered by drilling is 18.0 feet at drill hole Stan-3, and the average thickness based on drilling information is approximately 11 feet. Deposits of alluvium border several of the streams in the area. The largest area of this material is in the valley of the Iaddle Fork of :RI,: sear Creek. Other areas of alluvium are in the valleys of Big Bear Creek and Howell Creek (pl. 2).
The U. S. Bureau of Mines drilled 10 holes for a total of 187.7 feet in the vicinity of the Stanford de)osit. Drilling was done by hand, using 3—inch post—hole augers of the Iwan type. Logs of the drill holes are in the appendix. Samples were taken at 5—foot i:_tervals or where the material showed a marked c' an The samples were prepared in a drying room at Troy, Idaho, and were sent to the Bureau of Mines, Northwest Experiment Station, Seattle, Wash., to be assayed. Twenty—two samples (1 granitic and 21 transported clay) were assayed for available alumina and available ferric oxide. Available alumina (A1,0 ) as defined by Skinner and Kelly (1949, 3 ' p. 6), is the amount of alumina extracted from clay that has been dried at 130° C. overnight, weighed, calcined at 700° C. for one hour, and boiled in a 20 percent solution of sulfuric acid for one hour. The quan— tity of available alumina has been shown to depend upon the degree of weathering, and thus on the kind and amount of clay minerls. In general, the more complete the wenthering, the higher the available alumina content. The available ferric oxide (Fe203) is defined as the percentage by weight of ferric oxide in the calcined clay that is soluble in 20 percent solution of sulfuric acid under the same conditions as above. Because ilmenite is not appreciably soluble in sulfuric acid, its iron content for the most part, is not available; therefore, the quantity of available ferric oxide is mainly dependent on the quantity of limonite and to a minor degree on the quantity of nontronite.
Granitic Residual Clay The amount of granitic residual clay in the Stanford area is quite small. It was identified in the basal 5.0 feet of drill hole Stan-7. A thin zone of granitic residual clay is probably --)resent beneath the transported clays in the southwestern edge of the West Block. The thin ness and the low grade of the granitic residual clays suggest that it may be correlative with the lower grade granitic residual clay near the base of the wer.thering profile at the Benson deposit, where the residual clay has a maximum thickness of more than 100 feet (Wilson and Goodspeed, 1934, p. 80). The granitic residual clays, derived from the granodiorite and re lated rocks, preserve the texture of the original rocks, and they grade downward into hard, unweathered rock. The best grades of these clays are white to gray in color, phut are locallz, stained yellow or brown by iron oxides. Kaolinite, the principal clay mineral, is formed from feld spar and to a minor extent from muscovite and biotite. Quartz remains unaltered and occurs abundantly throughout the Granitic residual clay. One sample of granitic residual clay was assayed by the U. S. :Bureau of Mines. This sample contained 11.5 percent available alumina, and 0.9 percent available ferric oxide.
Basaltic Residual Clay The basaltic residual are the result of the weathering of the lower Columbia River basalts during the Excelsior interval. If the drainage was poor, the plagioclase and basaltic _lass were altered to nontronite (Allen and Scheid, 1946, p. 209); but if the drainage was good, kaolinite was formed from plagioclase and migrated along cracks and, o-pen cavities. Good drainage was usually present in the upper part of the weathering profile during the Excelsior interval, and poor drainage was usually present in the lower part of the profile. The residual clay retains the original basaltic texture to some degree. The fine— and even—grained texture is sharply defined by the abundant, small, uniformly disseminated flakes of blue—black ilmenite. Thus, the texture in the residual clay is more sharply defined than the fresh basalt, in which the texture is locally indistinct when ex— amined with a hand lens. The best high—alumina basaltic residual clays are composed almost entirely of kaolinite and unaltered ilmenite, and are plastic. The residual clays are bluish gray from the metallic blue— black ilmenite. In ,places they are stained yellow or tan by alteration products derived from ilmenite. No assays were made of basaltic residual clay.
Transported Clay The transported clays of the Upper Latah formation comprise poten tially all the high-alumina and ceramic grade clays of the Stanford deposit. The Latah formation is composed primarily of weathered debris from the Belt rocks, the granodiorite and related rocks, and to some extent the volcanic rocks. It was deposited upon the granitic and basaltic residual clays in lakes that were formed by streams dammed by post-Excelsior interval flows of basalt. The best high,-alumina transported clays are generally plastic, light gray or yellow, and occasionally -oink. Kaolinite is the principal clay mineral in the trans-,ported clays. It resulted from the weathering of feldspar and to a minor extent from the weathering of muscovite and -ciotite of the older formations. The kaolinite was formed before being transT)orted and deposited. The clays also contain a certain amount of fine-grained quartz and muscovite flakes. Many sandy and pebbly beds exist in the lower part of the u79per Latah formation. Twenty-one samples of trmisported clay were assayed. The average values are as fol7ows: available alumina, 17.2 -)ercent and aVailable ferric oxide, 2.0 percent.
Ceramic data Information published. by Skeels 0920, p. shows that there are many deposits of clays throllehout Latah County usable for most ordinary ceramic uses. Skinner and Kelly (1949, p. 37), furthermore, made many ceramic tests on a large number of samples of high—alumina transported clays of the Olson deposit. They demonstrated that a high degree of correlation existed between the refractoriness and the nercentage of available ferric oxide and available alumina (Skinner and Kelly, 1949, p. 8). Many of the clays at the Olson deposit were shown to be suitable for Litermediate heat duty (pyrometric cone equivalent of 26 to 31) and high heat (p. C. E. 31-33), while some were suitable for super heat duty (p. C. E. 33). The transported clays of the Stanford deposit are very similar to those of the Olson deposit, and they would probably yield similar ceramic results. Judging from the work of Skinner and Kelly, nearly all clays containing more than 12 percent available alumina and not more than percent available ferric oxide would be usable for ceramic products.
CL.Z DEPOSIT General Features The Stanford clay deposit consists entirely of transported clay of the upper Lrtah formatio—. There are, however, both granitic residual and basaltic residual clays in the area surround_lc the Stanford deposit. The granitic residual_ clay is the product of the weathering of gran— itic rocks in place, and the basaltic residual clay is the product of the weathering of basalt in place. The transporter:, clays are derived primarily from the weathered debris of the granitic rocks that has been transported and deposited in water. "'or purposes of discussion, the deposit has been divided into the West, Middle, and East Blocks. The lateral extent of the deposit is limited mainly by the -present stream valleys. The minable limit of the high—alumina clays in the West and Middle Blocks has been determined from the chemical assays. The overburden is composed mostly of the Palouse formation, which averages about 11 feet in thickness. The ratio of overburden to high— alumina clay is about 0.8 to 1. CONCLUSION Under emergency conditions the Stanford clay deposit could serve as a source of amminum. The deposit contains large reserves of clay for ceramic wares such as: brick, terra cotta, and drain tile.
Allen, V. T., and Scheid, V. E., 1946, Nontronite in the Columbia River region: Am. Mineralogist v. 31, D. 249-312. Bryan, Kirk, 1927, The'Palouse Soil" problem: U. S. Geol. Survey :Dull. 790—B, . 21-45. Pvrdee, J. T., and Bryan, Kirk, 1926, Geology of the Latah formation in relation to the lavas of Columbia Plateau near Spokane, Wash.: U. S. Geol. Survey Prof. Paper 140—A. Scheid, V. E., 1946, Excelsior high—alumina clay deposit, Spokane County, Wash.: U. S. C-col. Survey Prelim. Rept. Scheid, V. E., Excelsior surface--an intra—Columbia River basalt weathering s=face (vbs.): Geol. Sec. America Bull., v. 53, no. 12, D. 1224-1225. Skeels, F. H., 1920, A -oreliminary report on the clays of Idaho: Idaho 19ur. Mines and Geoloy Bull. 2. Skinner, K. G., and Kelly, H. J., 1949, Preliminary ceramic tests of clays form seven Pacific Northwest deposits: U. S. Bur. Mines Re7)t. Inv. Wilson, Hewitt, and Goodspeed, G. E., 1934, Kaolin and china clay in the Pacific Northwest: Washington Univ. (Seattle) Exper. Sta. Ser. Bull. 76.
APPENDIX: DRILL HOLE LJGS ANI ASSAYS Interval Available Available oration (feet) Description Fe2O3 A1233 DA.11 Hole Stan-1: ,ocrd. 27,410 N, 6,750 F. Qp 0.0--1:.2 Soil and Palouse formation. Drilling stopped because of hardness. Drill liole Stan-2: Coord. 26,310 N, 4,950 Qp Soil and Palouse formation. Tlu Clay, transported, tan sandy, sliEhtly micaceous, tLin Emonite band. Clay, transported, light to dark gray. 15.2-17.4 Clay, transpori,ed, light gray, pinkish gra7-streaked, many small kaolin lumps. 17.4-25.0 Clay, transported, light yellow, sandy, slightly micaceous, iron-stained layers. Drill Hole Stan-3: Coord. 27,150 N, 7)440 Qp Soil and Palouse formation Tce 18.0-22.0 Clay, residual, basaltic, green. Basalt.
Formation Interval (feA) 1)escription Available Fe2O3 Available Al203 Drill Sole A 4: Coord. 26,730 N, 12,070E. ':1D 0.0 - 12.0 ,;oil and. Palouse formation; 1/4 inch limonite band. Tlu 12.0 - 1-.0 Clay, transported, white, hard, dry. 16.0 - 17.0 Clay, transported, white, iron-stained, hard dry Drilling stopped because of hardness. is ri11 Hole L) tan-5: Coord. 31,170 N, 9,230 E. p - 0.0 - 10.0 Soil and Palouse formation. 1u 10.0 - 17.0 Clay, transported, micaceous, iron-stained; one thin limonite band. A.6 rill ole Stan-6: Coord. 28,640 14, 9,340 E; Elev. 2789.7 ft. Tlu 0.0 - 10.0 Clay, transported, gray and white, plastic. 10.0 - 14.0 Uay, transported, sandy, micaceous, iron-stained. 14.0 - 20.0 Sand, transported, yellow, micaceous. 20.0 - 24.0 Sand, transported, yellow, micaceous. Drilling stopped because of inadequate equipment.
Formation Interval (fect) Description F15203 Available A1203 Drill Hole Stan -7: Coord 26,940 U, 2,120 E. 13.0 Soil and Palouse formation; last 2 feet contains 1/2 inch quartz pebbles. Kg 1? . .0 Clay, residual, granitic, fine-grained toward bottom. Drilling stopped because of inadequate equipment. 0.? Drill Hole Stan-8; Coord. 26,610 N, 3,670 E. Tlu 6.0 Clay, transported, iron-stained to viite. 10.0 Clay, transported, dark gray. 12.0 Clay, transported. 15.5 Clay, transported, sandy, iron-stained. Drilling stopped because of hardness. Drill :Joie Stan-9: Coord. 26,620 N, 3,730 E. zN3 Tlu 8.0 Clay, transported, sndy, iron-stained, 1/4 inch limonite band. 9.0 Clay, transported. 11.0 Clay, transported, white to yellow, candy. 34.0 Clay, transported, white, sandy. 18.0 Clay, trcnsported, yellow, sandy; 4-inch beds of waxy white clay. Layer of white quartz grains at bottom. Lrill stopped because of inademlate equipment.
Interval Available AvaLlable : --ormation (feet) Description Fe2O3 A1203 Lrill Hole Stan-10: Coord. 30,890 N, 10,080 E. 7.0 — 2.0 Soil and Palouse ,or ation 2.0 — 2.5 LI ,onitc. Tlu 2.5 — 5.0 Clay, transported, yellow, iron—stained. 5.0 — 10.0 Clay, transported, white, :Icaceauz. 10.0 — 15.0 Clay, transported, white, plastic. 15.0 — 1I.J.0 Clay, transported, iron—stained, thin lionite bands.
WERT BOOKBINDING MIDDLETOWN ►A AUG 84 we're Ovek, Sound
Plates & figures from the original
