Index to Volume 15, 1946-1952*

Home , Cochetopa Dome, Mount Rosa (Colorado), Weber Formation

Colorado Scientific Society . Proceedings

(l)

INDEX TO

VOLUME 15

1946-1952

PUBLISHED BY THE SOCIETY DENVER, COLORADO 1956 Colorado Scientific Society

B. F. LEONARD, President DAVID J. VARNES, Vice-President ROBERT c. PEARSON, Secretary LYMAN C. HUFF, Treasurer

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COLORADO SCIENTIFIC SOCIETY Denver Public Library Denver, Colorado

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COLORADO SCIENTIFIC SOCIETY Box 688 Denver 1, Colorado

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PRINTED IN U. S . A. PEERLESS PRINTING COMPANY DENVER, COLORADO CONTENTS OF VOLUME 15 PAGE No. 1- Fluorspar deposits of the J amestown district, B oulder County, Colorado, by E . N . Goddard...... 5 N o. 2-Preliminary report on the Kokom o mining district, Colorado, by A. H. Koschmann and F. G. Wells...... 51 Replacement deposits (Kokomo district), by A. H. Koschmann, F. G. Wells, and J . W. Odell...... 100 No. 3-Vanadium deposits near Placerville, San Miguel County, Colorado, by R. P. Fischer, J . C. H aff, and J . R. Rominger...... 117 Recent development on the Black Bear vein, San Miguel County, Colorado, by D . J . Varnes...... 137 No. 4-Stratigraphy of the Pando area, Eagle County, Colorado, by Ogden Tweto ...... 149 No. 5-The Gunnison F orks sulfur deposit, Delta County, Colorado, by McClelland G. D ings...... 237 No. 6-Geology and fluorspar deposits of the St. Peters Dome district, Colorado, by T homas A. Steven...... 259 No. 7-The Sunnyside, Ross Basin, and Bonita fault systems and their associated ore deposits, San Juan County, Colorado, by W. S. Burbank...... 285 No. 8-Sources of lightweight aggregates in Colorado, by Alfred L. Bush...... 305 No. 9-Clay deposits of the Denver-Golden area, Colorado, by Karl M . Waage...... 373 Index- by Priscilla C. P atton and Marion C. Snipes...... 391

llJ I LLUSTRA TIO NS PAGE No. 1 P late 1. Geologic map of the central part of the Jamestown dis trict, Boulder County, Colorado, showing distribution of tho principal fluorspar doposits...... 11 2. Ooolo11lc map of tho principal fluorspar-producing area near Jamestown, Boulder County, Colorado...... 15 3. Geologic map of the D luo Jay mlno nnd vicinity...... 15 4. Fluorspar oro from the Argo br eccia zone, showing granite fragments (Iight groy) surrounded by fine- grained sugary fluorite (dark gray). Somo clay minerals ond quartz oro mlxod with the fluorite. (Scale in lnchos) ...... 15 5. Fluorspor ore from veins. A. Specimen from Blue Jay vein showing breccia fragments of deep-violet fluorite (black) in matrix of fine-grained fluorite, clay minerals, carbonate, and quartz. B. Specimen from Yellow Girl vein showing brec ciated pu rple fluorite (light to dark gray, glassy) in o fine-grained matrix of fluorite, clay minerals, quartz, and carbonate ...... 16 6. Geologic maps and sections of the Argo mino...... 33 7. Geologic maps and sections of the Brown Spor mlno...... 35 8. Geologic maps and sections of the Burlington mlno...... 37 9. Geologic maps and sections of the C honcollor mlno...... 39 10. Geologic maps and sections of the Emmott mlno and tho Afterthought tunnel ...... 41 11. Geologic map and sections of the Yollow Olrl mlno...... 47 F igure 1. Index map of Colorado showing tho locatiIon of tho Jamestown district ...... 7 2. Sketch showing lenticular body of stratified fragmental fluorspar material in granite broccio; east wnll of cross- cut, 125 feet northwest of shaft, 280-foot lovol of E m- mett mine ...... 23 No. 2 P late 1. Geologic map and sections of tho Koko mo mining district, Colorado. Southwestern part...... ( In pocket) 2. Geologic map of Kokomo mining district, Colorado. Northeastern part ...... (in pocket) No. 3 P late 1. Map of the Placerville area, Son Miguel County, Colo ..... 121 2. Maps showing the geology and oro bodlo• o f !our vana dium mines near Placervillo, Colorodo...... 130 Figure 1. Vertical sections across elongoto oro bodies, showing dif- ferent forms of rolls...... 126 P late 1. Map of the Treasury tunnel ond vicinity showing veins, faults, and u nderground workings, Ouroy, Colorado...... 146 2. Geologic map of Black Bear vein, Troosury tunnel, Ou- ray, Colorado ...... 146

IV ILLUSTRATIONS (Continued) PAGE N o. 4 Figure 1. Index ma p of part of central Colorado...... 151 2. Generalized geologic map of the Pando area...... 153 3. Cross-section showing relation of the Peerless, Harding, and Chaffee formations...... 166 4. Sections showing features of the Gilman sandstone member ...... 182 No. 5 Figure 1. Index map of southwestern Colorado showing location of the Gunnison Forks sulfur deposit ...... 238 2. Geologic map of the Gunnison Forks sulfur deposit and vicinity ...... 238 3. Geologic map and cross section of the quarry, Gunnison Forks sulfur deposit...... 238 No. 6 Figure 1. Index map showing the location of the St. P eters Dome district, Colorado ...... 260 2. Geologic map of the St. Peters Dome district, El Paso County, Colorado ...... 264 3. Structural map of the St. Peters Dome district, El Paso County, Colorado ...... 267 4. Geologic map of the Mattie B . deposit...... 275 5. Geologic map of the Duffields deposit...... 277 6. Topographic map of the Timberline deposit...... 279 7. Geologic map of the Timberline tunnel...... 281 8. Geologic m ap of the surface workings near the northern end of the Timberline deposit...... 283 No. 7 Figure 1. Index map of southwestern Colorado, showing location and structural setting of the Eureka-Gladstone-Animas Forks area ...... 290 2. Outline structure map of the Eureka, Animas Forks, and Gladstone areas, San Juan County, Colorado...... 292 3. Geologic cross-section from t he South Fork of Cement Creek n ortheast to California M ountain...... 293

No. 8 Figure 1. Index map of Colorado and northern N ew Mexico showing areas covered by figures 2-6 ...... betwe en 308-309 2. M ap of a part of n orth-central Colorado, sh owing the lo cation of deposits of lightweight aggregat es.... b etween 308-309 3. Map of Eagle County, Colorado, and parts of adjacent counties showing the location of deposits of lightweight aggregates ...... between 308-309 4. Map of Douglas County, Colorado, and p arts of adjacent counties, showing the location of deposits of lightweight aggregates ...... b etween 308-309

V I ILLUSTRATIONS ( Conlinued)

PAGE Figuro S. Map, of n part or central Colorado, showing the location of deposits of light weight aggregates ...... between 308-309 6. Map of a part of south-central Colorado and north central Now M oxlco, showlng t ho location o f deposits of lightweight aggrogalos ...... b otwoen 308-309 No. 9 F igure 1. Generalized stratigraphic section of rocks exposed in the D enver-Golden area ...... 375 2. Index m ap of the D enver-Golden area ...... 377 3. Clay-bearing strata in and adjacent to the D akota hog back in the D enver-Golden area...... 3 79

vi Colorado Scientific Society

PROCEEDINGS

INDEX TO VOLUME 15, 1946-1952*

By PRISCILLA C . PATTON and MARION C . SNIPES

U. S. GEOLOGICAL SURVEY DENVER FEDERAL CENTER, DENVER, COLORADO (All place names refer to localities in Colorado. Some of the features shown on the illustrations are indexed, but such indexing is not uniform.) Abe Lincoln Number 2 deposit American Metals Company (Koko (Chaffee Co.), vermiculite, 333 mo dist.) , 55 Adularia (Jamestown dist.), 18, 22 American Smelting & Refining Cor Afterthought tunnel (Jamestown poration (Leadville) dist.), 42 slag from, 346-34 7 Aggregate, lightweight American tunnel of Gold King mine bibliography, 352-368 (Eureka dist.), 289, 303 characteristics, 307-309 Ankerite (Jamestown dist.), 18, 34, classification of, 308 35, 36, 41 compared with normal-weight aggregate, 306, 307, 309 Aplite dikes (St. Peters Dome dist.), defined, 306 263, 264, 268, 270,277 properties of, 308 Arapahoe formation, 386 sources in Colorado, 305-368 Dawson arkose (Denver-Golden by commodity, 314-348 area), 378, (Castle Rock area), by county, 311-313 386-387 by deposit, 348-352 Arfvedsonite (Jamestown dist.), 18, Aggregate, normal weight 26 compared with lightweight aggre Argentine gate, 306, 307, 309 dike (San Miguel Co.), 138, 145, defined, 306 146 Alamosa Creek deposit (Conejos fissure (San Miguel Co.), 145 Co.), see Capulin deposit vein (San Miguel Co.), 146 Alice mine and vein (Jamestown Argentite dist. ) , 19, 21, 30 Kokomo dist., 107 Allanite San Miguel Co., 142 Kokomo dist., 78, 79, 80 Argo mine (Jamestown dist.), 19, Pikes Peak granite (St. Peters 22-23, 31-33 Dome dist.), 263 Allen deposit, Phares and, (Custer Arkansas smelter (Leadville), 51 Co.) Aurand, H. A., 8, 261-262 'vermiculite, 337-338 Bald Mountain stock (Kokomo Alum dist.), 75, 79-80 Gunnison Forks area, 253 Barite near Doughty Springs (Delta Kokomo dist., 104 Co.), 253 St. Peters Dome dist., 273, 274, see also Potash alum, Pickeringite 280, 282

*Publication authorized by the Director, U. S. Geological Survey. 391 392 INDEX

Basalt Mountain (Eagle Co.) Bonita Peak fault and fault block perlite at, 331 (Eureka dist.), 293, 294, 295, 302 pumice at, 318 Boston Cooney mine (Kokomo dist.), Base metals (Eureka dist.), 295, 106 296, 301 Boulder County, see Jamestown dis Bassem Park (Park Co.) trict pumice, 318 Boulder Creek granite (Jamestown Basset, C. F., 191 dist.), 10 Batholith (Jamestown dist.), 10 Boulder Fluorspar and Radium Co., Battle Mountain formation (Pando 31, 33, 35, 40 area), 189, 191, 201, 204 Boyd smelter (Boulder), 9 Bear Creek mine (Placerville area), Breccia reefs (Jamestown dist.), 10; 121, 123, 125, 127, 132-133 see also Breccia zones Behre, C. H., 90, 177 Breccia zones (Jamestown dist.), 13- Beidellite-montmorillonite group 14, 21-27; 29-46 passim (Jamestown dist.), 18 Breene mine (Kokomo dist.), 68, Belcher mine (Kokomo dist.), 94 101 Belcher vein (Eureka dist.), 300 Brill, K. G., 73, 189, 190, 191, 192, Belden shale 193, 201, 203, 204, 229 member of Battle Mountain for Brown Spar mine (Jamestown dist.), mation, 189 19, 24, 28, 35-36 Pando area, 184, 187, 189, 191, Burbank, W. S., 137, 145 192-193, 205, 228 Burbank, W. S., The Sunnyside, Ross Bell, W. C. Basin, and Bonita fault systems fossil identification, 159 and their associated ore deposits, Bentonite San Juan County, Colorado, 285- B lack Mountain, 316 304 Gunnison Forks area, 242 Burchard, E. F., 45 near Kokomo dist., 73 Burlington mine (Jamestown dist.), Benton shale (Denver-Golden area) 19, 22-23, 36-38 clay, 378, 384, 387, 388 Burns quartz latite, see Silverton Bilk Creek sandstone and marl mem volcanic series ber (Placerville area), 122 Bush, Alfred L., Sources of light Black Bear weight aggregates in Colorado, 305- fracture (San Miguel Co.), 146 368 mine (San Miguel Co.), 138, 142 Butler, B. S., 58, 76 vein (San Miguel Co.) Butler, G. M., 388 paragenesis and mineralogy, 141- Caldera, 138, 286, 289, 293 144 Cambrian rocks recent development, 137-146 Kokomo dist., 58-59 Black Mountain deposit (Park Co.) Pando area, 158-165 pumice, 316 Quartzite (Routt Co.), 323 Blue Creek flats ( Eagle Co.) Camp Bird vein (San Miguel Co.), pumice, 318 142 Blue Jay Hill, veins on, (Jamestown Cannibal Plateau (Hinsdale Co.) dist.), 34 pumice or scoria, 318 Blue Jay mine and vein (Jamestown Capulin (Alamosa Creek) deposit dist.), 14, 17, 19, 33-34 (Conejos Co.) "Blue" limestone (Pando area), 169, pumice, 315-316 177 Carbonaceous shale Bonanza vein (Eureka dist.), 300 Dakota sandstone (Gunnison Forks Bonita fault and fault system (Eu area), 237, 241, 242, 245, 246 reka dist.), 286, 292-293 Carpenter mine (Placerville area), ore in, 294, 295, 296-300, 302, 133-134 303 Cashier vein (Eureka dist.), 300 INDEX 393

Castle Rock area (Douglas Co.) Purgatoire formation, 384, 387-388 welded tuff, 344-345, 346 refractory Cathedral deposit (Saguache Co.) bentonite-like (Denver - Golden perlite, 329-330 area), 381 Cather Springs deposit, see Timber Glencairn shale member of the line deposit Purgatoire formation, 376, Chaffee formation (Pando area), 380-383, 388 168 kaolinite, 383 Dyer dolomite member, 169, 174- reserves (Denver-Golden area), 177, 180-181 383-384, 389; (Pueblo-Canon "sand grain marker," 175, City area) , 389 176 reserves, 386 section, 175-176 Clay deposits of the Denver-Golden Parting quartzite member, 156, area, Colorado, by Karl M. Waage, 162, 163, 169-174 373-390 section, 171-173 Clinker, 309 Chalcedony (Jamestown dist. ), 18, Coal 35 Dakota sandstone (Gunnison Chalcopyrite Forks area), 242, 245 Jamestown dist., 20, 30, 32 Laramie formation (Denver-Gold Kokomo dist., 99 en area), 385 St. Peters Dome dist., 282 Cochetopa Dome deposit (Saguache Champion mine ( Kokomo dist.), 67, Co.) 95, 101 perlite, 3 16-317, 330-331 Chancellor mine and vein (James pumice, 3 16-317, 318 town dist.), 19, 21, 38-40, 44, 45 volcanic ash, 31 7 Cherokee age, see Des Moines age Collapse structures ( Pando area) , Chonolith (Kokomo dist.), 74-75, 181-184 110 Colonel Sellers mine (Kokomo dist.), Chromium, 125, 128, 129 68, 101 Cinder, see Slag Colorado Fuel & Iron Corporation Cinder cone (Costilla Co.), 319 (Pueblo) Cinnamon fault (Eureka dist.), 291, metallurgical fluorspar shipped to, 292 38 Clark, Clark H ., 9, 43, 45 slag from, 346 Clarke, F. W., 251, 252 Colorado shaft (St. Peters D om e Clay dist.) , 264, 267 Benton shale, 384 Colorado, Sources of lightweight ag bloating-type, 374, 375, 388 gregates in, 305-368 brick, t ile, sewer pipe, 374, 376, Colorado Va nadium Corporation, 384-389 120, 121, 133, 134 Dakota sandstone (Pueblo-Canon Columbine mine (Kokomo dist.), 95 City area), 381, 389 Concrete, lightweight aggregate for, Dawson arkose ( Castle Rock area), 306-308 378, 384 , 386-387 Conger Mesa (Routt Co.) Fountain formation, 384, 387 scoria, 322 Laramie formation, 374, 376, 384- Consolation mine (Jamestown dist.), 386 40 lightweight aggregate, 309, 347-348 Copper bibliography, 358-361 Eureka dist., 286, 296 Lykins formation, 384, 387 J amestown dist., 21, 33 Morrison formation, 384, 387 Kokomo dist., 56 outlook, 389 San Miguel Co., 14 5 production (Denver-Golden area), Crater deposit ( R outt Co.) 374, 384-389 scoria, 322 394 I NDEX

"Crater Mountain" (Chaffee Co.) Pennsylvanian (middle) p umice, 318 Cherokee age, 193, 205 scoria, 325 P ando area, 192, 199, 202, 205 Crawford, R. D., 79 Devil Lake (H insdale Co.) Cripple Creek district, 266 scoria or pumice, 3 18, 326 compared with St. Peters Dome Devonian rocks (Pando area), 169, dist., 274, 276 177 Cripple Creek caldera, 276 Dikes Cripple Creek granite Jamestown dist., 22, 41, 44 related to Pikes Peak granite, 263 St. P eters D ome dist., 263, 264, Cross, Whitman, 81, 83, 261, 289, 268, 270, 277 302, 376 Dings, McCleiland G., Gunnis on Cryolite pegmatite (St. Peters Dome Forks sulfur deposit, Delta Coun dist.), 261, 262, 263, 265 ty, Colorado, 237-256 Dakota group, 3 78 Dolomite member, see Leadville Dakota sandstone, 383 dolomite Denver-Golden area, 380-381, 389 Donner, H. F., 189, 323 Gunnison Forks area, 240 - 242, Dotsero Crater deposit (Eagle Co.) 246, 247, 248, 254 scoria, 321-322 alums, 253 Doughty Springs (Delta Co. ) , 248, bentonite, 242 252, 253 carbonaceous shale, 237, 241, Duffie lds deposit (St. Peters Dome 242, 245, 246 dist.), 270, 276, 277, 278, 280 coal, 242, 245 Dyer dolomite member, see Chaffee "fertilizer" rock, 23 7 - 238, formation 243-247 Eagle County, see Kokomo district; gas seeps, 247-248, 250, 252 P ando area gold, 254 East mine (Kokomo dist.), 101 pyrite con cretions, 242, 245, Eldorado mine ( Kokomo dist.), 101 254 E ldridge, G. H., 188, 376 sulfur, 248-252 Elk Mountain porphyry P lacerville area, 122 Kokomo dist., 74, 77-78 Pueblo-Canon City area, 380- P ando area, 230, 231, 232, 233 381, 389 E lk Ridge limestone (Kokomo dist.), D and G tunnel ( K okomo dist.), 98, 62, 67 100 Elk Ridge limestone member, see Daughenbaugh shaft (Kokomo dist.) , Minturn formation 95 El Paso County, see St. Peters D ome D awson arkose district clay (Castle Rock area), 378, 384, Emmett mine and vein (Jamestown 386-387 dist.), 17-29 passim, 40-42, 44 tuff, welded, 344-345 Emmons, S . F., 56-108 passim, 160, Delaware mine (Kokomo dist.), 68, 174, 186, 188, 201, 204, 229, 376 101 Empire Zinc Company (Gilman), Delphos mine (Kokomo dist.), 94 175 Delta County, see Gunnison Forks Enargite (J amestown dist.), 19 sulfur deposit En echelon structures (St. Peters Denver County, see Denver-Golden Dome dist.), 271, 272, 276 area E ntrada sandstone (Placerville area) Denver formation, 378, 3 86 vanadium-bearing, 121-125, 134 Denver-Golden area Epithermal veins clay deposits, 3 73-390 fluorspar (St. Peters Dome dist.), stratigraphic section, 3 75 273-274 Des M oines age Eureka district (San Juan Co.) Pennsylvanian (lower) fault system s and ore deposits, Kokomo dist., 64, 66, 68, 69 285-304 INDEX 395

Eureka rhyolite, see Silverton vol• Chaetetes, 198, 201, 214, 217, 220 canic series corals, 217 Fall Creek mine (Placerville area), crinoids, 201, 212, 213, 217 121, 126, 130-131 Dicellomus, 159 Felicia Grace mine (Kokomo dist.), echinoids, 212, 213 67, 101 fish scales, 226 "Fertilizer" rock fusilinids, 199, 202, 208, 211, 212, composition, 246-247 213 Gunnison Forks a rea, 243-247 gastropods, 203, 205, 210, 211, production, 244 212, 213 F inlay, G. I., 261, 263, 265, 380 horn corals, 212 Fischer, R. P., 119 Mesolobus mesolobus, 203 F ischer, R . P., Haff, J. C., and ostracods, 193, 208, 226, 227 Rominger, J. F., Vanadium deposits pelecypods, 193, 203, 217 near Placerville, San Miguel Coun plants, 210, 213, 214, 215, 223, ty, Colorado, 117-134 226 Flattop penep lain (Jamestown dist.), reefs, 198 25-26 stigmaria, 214 Florissant lake beds, 276 trilobites, 159 Fluorite, see Fluorspar Fountain formation (Den ver-Golden Fluorspar area) Jamestown dist. (Boulder Co.), clay, 378, 384, 387 5-47 Fourney deposit (Jackson Co.) acid-grade fluorspar, 9, 20 vermiculite, 340-342 analyses and grade, 19, 20, 27 Frazier mine ( Placerville area), 132 m etallurgical - grade fluorspar, Free America mine (Kokomo dist.), 9, 20 69, 109 St. Peters Dome dist. (El Paso Fremont limestone, 168 Co.), 259-284 Friedhelm claim (Jamestown dist.), Fluorspar deposits of the Jamestown 38 district, Boulder County, Colorado, Front R ange highland (Paleozoic), by E. N. Goddard, 5-47 155-156, 197 F ossils (Gunnison Forks area) Front Range mineral belt (James plants, 242, 245 town dist.), 9 Fossils (Kokomo dist.) Galena cephalopods, 68-69 Jamestown dist., 19, 20, 32, 37 Domatoceras, 69 Kokomo dist., 105 Mooreoceras, 69 St. Pete rs Dome dist., 273, 282 nautiloid, 69 "Gapco Sulfor Base Soil Condition orthoceroid, 68 er," 238 Pseudorthoceras, 69 G arnet Chonetes, 66 J a mestown dist., 18 fusilinids, 66 Kokomo dist., 70 gastropods, 69 Gas seeps M arginifera, 66 D akota sandstone ( Gunnison Spirifer, 66 Forks a rea), 247-248, 250, 252 Fossils (Pando area) G azin , G. L ., 276 algal, 163, 198, 205, 207, 210, 213, Gearksutite (Jamestown dist.), 18 234 Gem Park deposit (Custer and Fre- borings, 163, 165 mont Cos. ) brachiopods, 159, 193, 203, 212, vermiculite, 338 213 General Agricultural Products Co., productid, 225 237-238, 244, 247 spiriferoid, 208 General Chemical Co., 9, 30, 36, 38, bryozoa, 212, 213, 225 39, 43, 45 cephalopods, 203, 205, 207 Genth, F. A., analyst, 123 396 INDEX

Geology and fluorspar deposits of the Harding quartzite ( Pando area), 156, St. Peters Dome district, Colorado, 162, 163, 166-169 by Thomas A. Steven, 259-284 section, 167 George Washington ore shoot, of H arry M. Williamson and Son, 9, Sunnyside mine (Eureka dist.), 31, 33, 35, 40 300-301. Hayden, F . V., 3 78 Gilman sandstone member, see Lead Haymon deposit (Park Co.) ville dolomite vermiculite, 343-344 Glencairn shale member, see Purga Headden, W. P., 248, 252, 253 toire formation Hematite (Jamestown dist.), 10, 18, Goddard, E. N ., 387 41 Goddard, E. N., Fluorspar deposits Henbest, L. G., fossil identification, of the Jamestown district, Boulder 64, 66, 199, 202, 213 County, Colorado, 5-47 Henderson, C. W., 53, 54, 55, 56 Gold Henson tuff, 288, 289 Eureka dist., 286, 295, 296, 298, Hermosa (?) formation (Pando 304 area), 188 in Dakota sandstone (Gunnison Hess, F. L., 119 Forks deposit), 254 Hillebrand, W. F., 123, 261 in fluorspar veins analyst, 123 Jamestown dist., 8, 20, 30, 33, Hoodoo claim (Jamestown dist.) , 38 39, 43 Hoosier reef (Jamestown dist.), 12 St. Peters Dome dist., 261-262, Hornsilver dolomite member, see 273, 278 M'. inturn formation Kokomo dist., 56, 107 Howe, Ernest, 289, 302 San Miguel Co., 142-145 Hughes Boss shafts and claim, on G olden-Denver area, see Denver Duffields deposit (St. Peters Dome Golden area dist.), 264, 276, 278 "Goldenite" mine (Custer and Fre Idaho Springs formation (Jamestown mont Cos.) dist.) ,9 vermiculite, 338 Idarado Mining Company, 139 Gold King mine and vein (Eureka Invincible mine (Jamestown dist.), dist.), 286, 289, 294, 296, 297, 298, 43, 46 303 Iron (Eureka dist.), 299, 304 American tunnel of, 289, 303 Iron vein (San Miguel Co.), 142 Gold-silver ore (Eureka dist.), 301 Jack 8 bed Goldstein, August, Jr., 332 of Minturn formation (Pando Gore fault, 155, 157, 186 area), 196, 197 Jack N o. 8 claim (Pando area), 196 Gossan (Kokomo dist.), 108 Jacque Mountain limestone Graben ( Eureka dist.), 292, 293 Kokomo dist., 60, 62, 68-69 Granodiorite (Jamestown dist.), 10, of Maroon formation (Kokomo 12, 13, 38-39, 46 dist.), 60 Great Mogul mine (Eureka dist.), P ando area, 188, 192, 204-208 299-300 J amestown district (Boulder Co.), Greer lead smelter (Kokomo), 54 Fluorspar deposits, 5-47 Gude, A. J., 3d, 384 origin of deposits, 22-27 Gunnison Forks sulfur deposit, Delta production and reserves, 8-9, 27-29 County, Colorado, by McClelland J efferson County, see Denver-Golden G. Dings, 237-256 area Haff, J. C ., see Fischer, Haff, and Johnson, J. H., 57, 85, 155, 168 R ominger Juniata mine (Kokomo dist.), 95 Half-Moon mine (Kokomo dist.), 95 Jurassic rocks H andicap vein (San Miguel Co.), Ent r a d a sandstone (Placerville 139 area), 121 INDEX 397

Karst topography Leadville dolomite (Pando area), 150, former, in Pando area, 184 177-186, 192, 207 Kimberly mine (Kokomo dist.), 56, dolomite member, 184-186 68, 101 hydrothermal alteration, 184 Kokomo district (Summit, Eagle, section, 185-186 and Lake Cos.) Gilman sandstone member, 174, faults, 90-96 177-184, 186 high-temperature deposits, 97- sections, 179-180 100, 110 "Leadville" limestone (Pando area), mineral deposits, 96-112 177 replacement deposits, 100 - 104, see also Leadville dolomite 111 Lee, W . T., 237 stratigraphic section, 62 Lehman mill (Jamestown dist.), 20, surficial alteration of ores, 106- 43 109 Leopard Creek, mineralized belt vein deposits, 104-106, 111 along, (Placerville area), 123, 125 Kokomo mining district, Colorado, Leroy, L. W., 384 Preliminary report, 51-112 Leyte open pit, on Duffields deposit Kokomo syncline (Kokomo dist.), (St. Peters Dome dist.), 264, 277, 89-90 278 Koschmann, A. H., 157, 195, 201, Lightweight aggregate, see Aggregate, 204, 229 lightweight Koschmann, A. H., and Wells, F. G., Lillie G prospect (Kokomo dist.), 99 Preliminary report on the Koko Lime Cliffs group of limestones mo mining district, Colorado, 51- (Minturn area), 201 112 Lincoln porphyry Koschmann, A. H., Wells, F. G., and Kokomo dist., 76, 80-81 Odell, J. W., Replacement deposits Pando area, 232 (Kokomo dist.), 100-104 Little Chief fault (Kokomo dist. ), Kramer Mines, Inc. (St. Peters 80, 94-95 Dome dist.), 276, 278 Locke, Augustus, 24 Lake County, see Kokomo district Loess (Denver-Golden area), 389 Lamproph yre (St. Peters Dome for bricks, 389 dist. ), 263, 265, 266, 270 Lovering, T . S., 25-26, 57, 85, 155, Landes, K. K., 262 177, 189, 387 La Plata limestone, see W anakah for Lucky Strike mine (Kokomo dist.), mation (Pony Express member) 56, 68, 101, 108 La Plata sandstone (Placerville area), Lykins formation ( Denver-Golden 121 area) Laramide structures (Kokomo dist.), clay, 378, 384, 387 89-96 Lytle member, see Purgatoire forma Laramie formation tion clay for brick, tile, sewer pipe, 3 74- MacQuown, W. C., Jr., 326 376, 384-386 Magnesia alum Denver-Golden area, 374-389 pas in Dakota sandstone (Gunnison sim Forks area), 253 Larsen, E. S., 289 Magnetite (Kokomo dist.), 70, 79, Lead 83, 99 Eureka dist., 286, 296, 304 Mancos shale (Gunnison Forks area), Jamestown dist., 21, 33 242, 246 Kokomo dist., 56, 104 Manitou limestone (Pando area), St. Peters Dome dist., 278 168, 169 Lead Carbonate mine (Eureka dist.), Marcasite (Gunnison Forks area), 294, 296-297, 298 254 Lead-silver ore (Jamestown dist.), 19, Marjorie Lode deposit (Custer Co.) 30, 31, 33 vermiculite, 333-335 398 INDEX

Maroon formation Molybdenite (Kokomo dist.), 98, 99- Kokomo dist., 60-61 100 Pando area, 187, 188, 189, 190, M o ntmori lloni te-beidellite group 191, 192, 201, 229-235 (Jamestown dist.), 18 Jacque Mountain limestone Morning Star deposit (Gunnison member, 188, 192, 204-205 Co.) section, 230-235 perlite (dikes), 328-329 Mattie B. deposit (St. Peters Dome Morrison formation dist.), 264, 267, 275, 278 Denver-Golden area Maxwell reef (Jamestown dist.), clay, 378, 384, 387 10, 12 Gunnison Forks area, 240 McCoy formation, 188, 191 Placerville area, 122 McDonald, A. C., 244, 246, 247 Mosquito fault McDonald, Jesse R., 105 Kokomo dist., 90-92 Meek, F. B., 378 Pando area, 155 Mesita deposit (Costilla Co.) Mountain King vein (Eureka dist.), scoria, 319-320 300 Metals Reserve Company, 120, 133 Mountain Queen vein (Eureka Miarolitic cavities (Jamestown dist.), dist.), 300 18 Mount Rosa granite, 265 Mica, vanadiferous, (Placerville Mount Saunders deposit (Eagle Co.) area), 123, 124 scoria, 320-321 Michigan mine (Kokomo dist.), 55, Murata, K. J., analyst, 255 68, 101, 108 Nathrop-Ruby Mountain deposit Miller, A. K., fossil identification, 69, (Chaffee Co.) 205 Mineralization stoping (Jamestown obsidian, 314, 327 dist.), 24-27 perlite, 314, 326-327 Minturn formation (Pando area), pumice, 314-315 187, 190, 191, 192, 193, 194-228 Nations Treasure mine (Jamestown Elk Ridge limestone member, dist.), 43-44 202-203, 209-211 New York mine (Kokomo dist.), 67, Hornsilver dolomite member, 95, 101 199, 201, 216-217 No Name vein (Eureka dist.), 301 J ack 8 bed, 196, 197 Nontronite (Jamestown dist.), 18 Jacque Mountain limestone North, V., analyst, 123 member, 204-206, 207-208 Obsidian (lightweight aggregate), Resolution dolomite member, 310, 3 13, 329, 347 199-201, 215-216 bibliography, 355-356 Robinson limestone member, sources in Colorado, 313, 314, 201-202, 211-215 329 sections, 207-228 Odell, J. W., see Koschmann, Wells, Wearyman dolomite member, and Odell 198-199, 217 Omega mine (Placerville area), 121, White Quail limestone member, 123, 125, 127, 131-132 203-204, 205, 207, 208-209 Ordovician rocks (Pando area), 166, oolitic, 203 169 Miocene rocks Pando area (Eagle Co.), Stratigra San Juan tuff (San Miguel Co.), phy, 149-235 138, 145 stratigraphic section, 152 Miocene veins (St. Peters Dome see also Fossils (Pando area) dist.), 276 Parkdale deposit (Fremont Co.) Mississippian rocks (Pando area), vermiculite, 338-339 177-192 Parker, Charles 0., analyst, 249, 251 Molas formation, 184, 187 Parting quartzite member, see Chaf - type material (Pando area), 193 fee formation INDEX 399

Peerless formation (Pando area), Porphyritic quartz monzonite (Ko 160-165, 166, 168, 169 komo dist.), 72, 75-76, 78 section, 164, 165 Porphyry Mountain stock (James Peerless shale member, see Peerless town dist.), 11, 12, 13, 18, 21-26 formation relation to fluorspar deposits, 22 Pegmatite Potash alum cryolite-bearing, 261, 262, 263, 265 Dakota sandstone (Gunnison Forks Jamestown dist., 22 area), 253 St. Peters Dome dist., 261-265 pas P otosi volcanic series (Eureka dist.), sim, 268, 269 288, 289 Peneplain, F lattop (Jamestown Powderhorn deposits (Gunnison Co.) dist.), 25-26 Number 1 Pennsylvanian rocks vermiculite, 339 Kokomo dist., 59-73 Number 2 Pando area, 186-235 vermiculite, 339-340 Pentada de! Norte Peak (Rio Grande Pre-Cambrian rocks Co.) J amestown dist., 9-10, 12 scoria reported, 326 Kokomo dist., 58 P erlite (lightweight aggregate), 347 Routt Co., 323 bibliography, 355-356 St. Peters Dome dist., 262-284 devitrified, 327 passim sources in Colorado, 311, 312, 313, with vermiculite, 332-344 passim 3 14, 326-331, 349-350 Preliminary report on the Kokomo Permian rocks mining district, Colorado, by A. H. Kokomo dist., 59-73 Koschmann and F. G . Wells, 51- Pando area, 186-192, 194-235 112 Phares and Allen deposit (Custer Primos Chemical Company, 119, 120, Co.) 121, 131, 132, 133 vermiculite, 337-338 Prosser's Rock deposit (Saguache Phosphoria formation Co.) State Bridge formation correlated obsidian, 329 with, 189 perlite, 329, 331 Picayune volcanic group, see S ilver Pumice (lightweight aggregate), ton volcanic series 347 Pickeringite bibliography, 356-357 Dakota sandstone (Gunnison Forks sources in Colorado, 311, 312, area), 253 313, 3 14-318, 348 Pikes Peak granite, 387 P u micite, 3 10, 348 St. Peters Dome d ist., 262-284 Huerfano Co., 331 passim P ark Co., 316 faulting in, 269-270 Purgatoire formation (Denver-Gold jointing in, 266-270 en area), 374-389 passim Pitchblende clay fer brick, t ile, sewer pipe, associated with fluorspar (James 3 78, 384-389 town dist.), 19, 34 clay, refractory, 3 76, 380, 381- Pittsburg smelter (Kokomo dist.), 53 384 Placerville area (San Miguel Co.), G lencairn shale member, 376, Vanadium deposits, 117-134 381-383 Pocahontas mine (Placerville area), Lytle sandstone member, 380 134 Purington, C. W., 302 Polvo Blanco deposit (Huerfano Co.) Pyrite pumicite, 331 Eureka dist., 298 P ony Express limestone member, see Gunnison Forks area, 242, 245, 254 Wanakah formation Jamestown dist., 19, 20, 30, 32, 37 Poorman claim, mine, and vein Kokomo dist., 64, 100, 103 (Jamestown dist.), 9, 45 St. Peters Dome dist., 282 400 INDEX

Pyroxene quartz latite , see Silverton Robinson limestone volcanic series Kokomo dist., 60, 62, 65-67, 101, Pyrrhotite ( Kokomo dist.), 103 102 Quail group of mines (Kokomo of Maroon formation, 60, 188 dist.) , 103 Pando area, 201-202, 211-215 Quail porphyry (Kokomo dist.), 80 Robinson mine (Kokomo dist.), 56, Quaintance Number 1 deposit (Jack• 67, 101, 102, 108 son Co.) Robinson syncline (Kokomo dist.), vermiculite, 340-341 88-89 Quartz monzonite (Kokomo dist.), Rolls (Placerville area), 125-127 75, 79-80 Rominger, J . F., see Fischor, Haff, Quartz monzonite, porphyritic, (Ko and Rominger komo dist.), .72, 75-76, 78 Roscoelite (Placerville area), 123, Quartz monzonite porphyry, sodic 124 granite-, (Jamestown dist.), 12-13, Rosita Hills deposit (Custer Co.) 18, 22 perlite, 327-328 Queen Anne vein (Eureka dist.), 300 Ross Basin fault and fault system Queen of the West mine (Kokomo (Eureka dist.), 286, 291, 292, 293 dist.), 93, 96, 104, 109, 111-112 ore in, 294-295; 298-304 passim Ross, C. S., analyst, 123 Quist Claim 72 deposit (Custer Co.) vermiculite, 336, 33 7 Roth, R., 188 Ruby Mountain deposit, see Nath Radioactivity of fluorspar (James rop-Ruby M ountain deposit town dist.), 19 St. Peters D ome district (El Paso Radiographs of pitchblende (James Co.), Geology and fluorspar de town dist.), 19 posits, 259-284 Ransome, F. L ., 289, 297 rock descriptions, 262-266 R are M etals Mining & Milling Com structure, 266-270 pany (Placerville area), 119, 120 vein deposition, 271-276 Recent development on the Black San Antonio M ountain deposit ( Rio Bear vein, San Miguel County, Arriba Co.) Colorado, by D. J. Varnes, 137- scoria, 324-325 146 Sanidine ( K okomo dist.), 82, 83 Red vein (Eureka dist.), 297 San Isabel deposit (Pueblo Co.) Replace,ment deposits ( K okomo vermiculite, 344 dist.), by A. H. Koschmann, F. G. San Juan County, see Eureka dis Wells, and J. W. Odell, 100-104 trict; Sunnyside, Ross B asin, and Resolution dolomite member, see Bonita fault systems Minturn formation San Juan tuff Resort Claim deposits (Jackson Co.) Eureka dist., 288 vermiculite, 340-341, 342 San Miguel Co., 138, 14 5 Rhodochrosite (Kokomo dist.), 104 San Luis Hills Rhodonite scoria reported, 325 E ureka dist., 294, 297, 304 San Miguel County, see Placerville Kokomo dist., 104 area; Black Bear vein Rhyolite ( Kokom o dist.), 70-71, 73, Sawatch quartzite 81-83 Kokomo dist ., 57, 58-59, 92 Rhyolitic p lug (Eureka dis t.), 299 Pando area, 156, 158-161, 162, 171 Rice, G. S., 26 Peerless shale membe r , see Richardson , G. B., 386, 387 Peerless formation R iebeckite ( St. Peters D ome dist.), Routt Co., 323 263, 265 Schaller, W. T., 144 Riveira deposit (Rio Arriba Co.) Scoria ( lightweight aggregate) scoria, 323-324 bibliography, 356-357 Robinson Consolidated Mining Com sources in Colorado, 311, 312, 313, pany (Kokomo dist.), 53 3 17, 318-326, 348-349 INDEX 401

Seller's Creek area (Douglas Co.) Sodic granite-quartz monzonite por welded tuff, 345-346 phyry (Jamestown dist.), 12-13, Selma mine (Kokomo dist.), 69 18, 22 Shale (lightweight aggregate), 347, Soil conditioner 348 "fertilizer" rock, 243-24 7 bibliography, 358-361 Gapco Sulfor Base Soil Condi Shale and clay (Denver - Golden tioner, 238 area), 374, 388 Sources of lightweight aggregates in Sheeted zone (Kokomo dist.), 81-82, Colorado, by Alfred L . Bush, 305- 93, 94 368 Sparling Ranch deposit (Custer Co.) "Shorty" Robison deposit (Custer Co.) vermiculite, 335-336 vermiculite, 333-335 Specularite (Kokomo dist.), 70, 99 Sphalerite Siderite (Jamestown dist.), 46 Jamestown dist., 19, 41 Si Ii ca te, vanadiferous, (Placerville Kokomo dist., 55 area), 123 St. Peters Dome dist., 273, 282 Silver Spicer, H. C., analyst, 19 Eureka dist., 286, 296 Spinney Mountain deposit (Park Jamestown dist., 20-21, 32, 33 Co.) Kokomo dist., 53, 56, 94, 104, 105, vermiculite, 342-343 106, 107, 108 Standard reef (Jamestown dist.), 12 St. Peters Dome dist., 261-262, State Bridge formation (Pando 273, 278 area), 187, 189, 191, 229 San Miguel Co., 142, 143, 145 Steven, Thomas A., Geology and "Silverite" mine (Custer and Fre fluorspar deposits of the St. Pe mont Cos.) ters Dome district, Colorado, 259- vermiculite, 338 284 Silver-lead ore (Jamestown dist.), Stocks 19, 30, 3 1, 33 Bald Mountain stock (Kokomo Silver Plume granite (Jamestown dist.), 75, 79-80, 110 dist.), 10, 11, 12, 31, 40, 41 Jamestown dist., 10, 12 Silverton volcanic series (Eureka Porphyry Mountain stock (James dist.), 286, 288 town dist.), 12, 13, 18, 21-26 Burns quartz latite, 288, 289, Tucker Mountain stock (Kokomo 291, 301, 302 dist.), 75, 77, 110 veins in, 301 Stoping, mineralization, (Jamestown Eureka rhyolite, 288, 289, 291, dist.), 24-27 301, 302 Stormking mine (Kokomo dist.), 98 Henson tuff, 288, 289 Stose, G . W ., 380 Picayune volcanic group, 288 Stratigraphy of the Pando area, pyroxene quartz latite, 288, 289, Eagle County, Colorado, by Ogden 296, 301 Tweto, 149-235 Singewald, Q. D., 173 Sulfur deposit, Gunnison Forks, (Delta County), 237-256 Slag (lightweight aggregate) Sulfur Gulch (Gunnison Forks) sul bibliography, 361-363 fur deposit, 237-256 blast-furnace, 313, 346-347, 352 Sulfur, native, ( Gunnison Forks cinder, 362-363 area) clinker (natural slag), 309 analyses for, 249, 250, 251 expanded, 361-362 "fertilizer" rock, 243-24 7 Slate (lightweight aggregate), 309 gas seeps, 247-248, 250, 252 bibliography, 358-361 origin, 251-252, 254 Smuggler mine (Kokomo dist.), 94 production (as fertilizer rock), Snowbank mine (Kokomo dist.), 55, 244 101, 108 Summit County, see Kokomo district 402 INDEX

Summit smelter (Robinson), 54 "Tung Ash" deposit (Chaffee Co.) Sunnyside Basin, see Sunnyside fault vermiculite, 333 system Turret deposit (Chaffee Co.) Sunnyside Extension vein (Eureka vermiculite, 332-333 dist.), 301 Tweto, 0. L., 177, 189 Sunnyside fault and fault system Tweto, Ogden, Stratigraphy of the (Eureka dist.), 286, 291, 292, 293, Pando area, Eagle County, Colo 299 rado, 149-235 ore in, 294-295; 301-304 passim Upper Alice mine (Jamestown dist.), Sunnyside mine (Eureka dist.), 286, 31 289, 292, 294-295 U. S. Vanadium Company, 119, 120, George Washington ore shoot, 121, 132 300-301 Uranium, equivalent Sunnyside, Ross Basin, and Bonita in fluorspar (Jamestown dist.), 19 fault systems and their associated Uthoff mine (Kokomo dist.), 55, 56, ore deposits, San Juan County, 68, 101 Colorado, by W. S. Burbank, 285- Vanadium (Placerville area), 117- 304 134 Sunnyside vein (Eureka dist.), 301 deposits, 122-128, 130-134 Swandyke hornblende gneiss (James production, 119-120, 134 town dist.), 9, 10 Vanadium Corporation of America, 120, 121, 131, 132, 133 Telluride conglomerate (Eureka dist.), 288 Vanadium deposits n ear Placerville, San Miguel County, Colorado, by Telluride, gold, (Jamestown dist.), 7 R. P. Fischer, J. C. Haff, and Tenmile fault (Kokomo dist.), 95-96 J. F. Rominger, 117-134 Tennantite (Jamestown dist.), 19, 32 Vanderwilt, J. W., 58, 76, 188 Tertiary rocks Van Tuy!, F . M., 25-26, 376, 385 Black Mountain (Park Co.), 316 Varnes, D. J., Recent development J a mestown dist., 10, 12 on the Black Bear vein, San Placerville area, 121 Miguel County, Colorado, 137-146 St. Peters Dome dist., 263-284 Veins passim Eureka dist., 286, 294-298, 300-304 Thermoluminescence of fluorite Jamestown dist., 13-14; 17-47 pas (Jamestown dist.) , 17 sim Timberline deposit (St. Peters Dome Kokomo dist., 97, 100, 104-106 dist.), 264, 272, 273, 276, 278, 279, St. Peters Dome dist., 270-284 280-282, 283 "Vermiculite King" deposit (Custer Titanite (Kokomo dist.), 78, 79 Co.) Toltec fault (Eureka dist.), 292, 293, vermiculite, 336-33 7 298-299 Vermiculite (lightweight aggregate), ore in, 294 306, 347 Topaz (Kokomo dist.), 83 bibliography, 357-358 Treasury tunnel (San Miguel and sources in Colorado, 311, 312, Ouray Cos.), 138, 139, 142, 144, 313, 331-344, 350-352 145 Volcanic ash (lightweight aggregate), Tucker Mountain stock (Kokomo 310, 348 dist.), 75, 77 sources in Colorado, 313 Tuff Volcanic Eureka dist., 288 cone (Routt Co.), 322 Kokomo dist., 70-71 neck (Eagle Co.) , 320; (Rio Ar San Miguel Co., 138, 145 riba Co.), 325 Tuff, welded ( lightweight aggregate), rocks 347 Eureka dist., 288, 289, 291, 296, sources in Colorado, 312, 344- 301, 302. 346, 352 Kokomo dist., 70-73 INDEX 403

San Miguel Co., 138, 145 White Quail lead smelter (Kokomo vent (Eagle Co.), 321 dist.) , 54 Volcano White Quail limestone (Kokomo Black Mountain (Park Co.), 316 dist.), 56, 62, 67-68, 101, 102, 103 deposit (Routt Co.), 322-323 White Quail limestone member, see Voss Land deposit (Custer Co.) Minturn formation vermiculite, 336-33 7 White Quail mine (Kokomo dist.), 67, 68, 94, 96, 101, 103, 108 Waage, K. M., 381 Wilfley mill (Kokomo), 55 Waage, Karl M ., Clay deposits of Wilfley mine (Kokomo dist.), 56, 68, the Denver-Go/den area, Colorado, 94, 101 373-390 Wilfley, Robert A., 55 Wanakah formation Wilfley, R obert D., 339 Bilk Creek sandstone and m arl Wilfley table, 55 member, 122 Wiilia ms, James Steele, fossil identi P ony Express limestone member, fication, 64, 66, 68, 69, 203, 205 121, 128, 129 Willow Peak (Garfield Co.) W ano mill (Jamestown), 9, 21, 40 scoria, 326 Wintergreen mine (Kokomo dist.) , Washington mine (Kokomo dist.), 69, 109 68, 101 Wyoming formation Wearyma n dolomite member, see K okomo dist., 60-61 Minturn formation P ando area, 188, 189, 191, 229 Weber formation ( Kokomo dist.), Yellow Girl mine and vein (James 60-61 town dist.), 18, 45-47 Weber (? ) formation (Pando area), Young deposit (Custer Co.) 19 1, 192 vermiculite, 335 grit, 186, 188 "Zebra rock" (P ando area), 185 limestone, 188 Zinc shale, 186, 188, 189 Eureka dist., 286, 299, 304 K okomo dist., 55, 56, 104 Weeks, H. J ., 237, 240, 247 St. Peters D ome dist., 278 Wells, F . G., 201, 204, 229 San Miguel Co., 145 see a/so Koschmann and Wells; Zircon and Koschmann, Wells, and Odell Kokomo dist., 78, 79, 83 Wheel of Fortune mine (Kokomo St. Peters Dome dist., 263 dist.), 65, 67, 101 Zoisite ( Kokomo dist.), 78