None
southern Appalachians, 74. Manganese oxides: association with gold- deposits, 786. occurrence in mining-districts, 174. reactions in dissolving gold, 778. Mangauese-salts : lateral migration from country-rock, 794. Manganite: association with gold, 793. Manhattan. Nev. : gold -deposits, 826. Manipori formation, South Island, New Zealand, 162. Map : New England and New York : normal chlorine, 769. Marble : San Jose, Tamaulipas, Mexico, 569. Marcasite : reducing power, 352, 357, 358. Marquette region, Michigan : iron-depos- its : origin, 71. vertical section, 639. Marsh-gas : association with ore-deposits, 345. reducing power, 350, 357. Martinique : volcanic gas : analysis. 388. May Belle Tunnel mine, Cripple Creek, Colo., 419. Melville, W. H. : analysis of sinter, 629. Mend en hall, W. C. : gold in aplite dikes, Alaska, 280. Mercury (see also Quicksilver) : relations to igneous rocks, 753. Mekbitt, W. H. : Discussion on Geological Distribution of Useful Metals in the United States, 90-91. origin of Sudbury nickel-ores, 483. Mesabi ore-deposit : vertical section, 640. Mesozoic gold-belt, 435-438. Metalliferous lodes : successive zones in depth, 789. Metalliferous province : definition, 293. relation to petrographic province, 293, 297. Metallographic province of California, 619. Metal lographic province of Nevada, 619.' Metals : distribution in sedimentary rocks, 254. in detrital rocks, 257. Metamorphism (see also Contact-nieta- morphism) : effects, 68. hydrothermal, 529. Sudbury district, Ontario, 514. Metasomatic interchange : definition, 3. Metasomatic processes, 232. in Fissure-Veins (Lindgren), xviii. Metasomatic replacement: explanation, 453. Tintic district, Utah, 342. Metasomatism: definition, xl. in Leadville ore-deposits, 2. in Scandinavian iron-ores, xxvii. Metastibnite : Steamboat Springs, Nevada, 632. Meteoric hypothesis : inadequacy for ore- deposition on Pacific coast, 589, Meteoric waters : circulation, 240. role in formation of ore-deposits, xix. Mexico : gold production, 435, 436, 438, 439. Cananea copper-deposits, 376, 396. Chihuahua: Guadalupe mine, 218. San Jos6 : ore-deposits, 237. Mica: in rocks of New Zealand and Vic- toria: analyses, 167-168. separation from rocks for examination, 164. Michel -Levy, A. : contact-metamorphic phenomena, 525. Microcline : crystallization from magmas, 609. Midget mine, Cripple Creek, Colo., 420. Mike fault, Leadville, Colo., 48. Miller, W. G. : Discussion on The Geology ical Features of the Gold- Production of North America, 445-446. Millerite : Sudbury, Ontario, 456. Mineral-bearing currents : direction of flow, 37. Mineral ridge, Tonopah, Nev. : mineral veins. 607. rocks, 604. silver-ores : genetic relations, 613. Mineral vein : genesis, 430. Mineral veins : Influence of Country-Rock on (Weed), 216-234. near igneous contacts, 394. Mineral zone, western America, 298. 944 INDEX. Mineralization : due to rich solutions, 700. of veins : rapidity, 700. source of ores, 710. Mineralized veins: product of expiring vulcanism, 698. Mineralizing agents: distribution in ig- neous rocks, 755. Mineralizing process : Tonopah, Nev., 594. Mineralizing solutions: source: Tonopah, Nev., 596. Minerals: isolated from rocks of New Zealand : analyses, 167. isolation for examination, 164. of secondary origin, 791. reducing power, 347, 357. segregation in magmas, 264. separation from rocks by solutions, 165. Mines (see also Gold-mines : Silver-mines, etc.) : of Rosita and Silver Cliff, Colorado (Emmons), 139-161. scarcity of commercially valuable, 696. Mine-timbers : examination for gold, 180. Mi ne- waters : acidity: cause, 174. average of analyses, 765. composition, 764. examination : apparatus and results, 180-181. vadose : acidity, 175. examination for free acid and ferric salts, 176, Mining-districts: areal distribution, 325. review, 805. Mint mine, Cripple Creek, Colo , 420. Mirabel mine, Lake county, Cal.: quick- silver, 79, Mississippi valley zinc-and lead-ores, 335. Missouri : lead -and zinc-deposits, 327. Sedalia: coal associated with blende, 320. Versailles: coal associated with blende, 320. Mitchener mine, Drury township, Sud- bury district, Ontario, 505. Mizpah silver-gold mine, Tonopah, Nev., [825]. Modoc limestone, Clifton-Morenci district, Arizona, 519, 523. Modoc porphyry, 224. Moissan, H.: analysis of volcanic gas, 3S8. Moj a ve desert : borax-deposits, [8351. Mojave Mining -District, California (Bate- son). 832. Molybdenite : San Jose, Tamaulipas, Mex- ico, 573. Molybdenum : distribution in igneous rocks, 750. in siliceous rocks. 285. Molybdenum-deposits: alteration, 135. Mongolia : Ku Shau Tzu : ore-deposition, 359. Montana : Bannack gold-deposits. 381. Butte : copper-veins, 224, 225, 403. silver- veins, 223. vein-formation, 220. Elkhorn district : ore-deposits, [239], 382. gold-production, 437. gold -quartz veins, 280. Jefferson county : Lump Gulch silver- gold-veins : genesis, 408. Montana: Madison county: ore-deposits produced by successive concentra- tions, 303-304. mineral veins, 228-229. Neihart: mineral veins, 227, 228. silver-lead mines, 219. Monument mine, Cripple Creek, Colo.. 419. Moon-Anchor mine, Cripple Creek, Colo., 420. Moonlight mine, Cripple Creek, Colo., 420. Morenci shale, Clifton-Morenci district, Arizona, 519, 523. Morencite, Clifton-Morenci district, Ari- zona. 519. Mosquito fault, Leadville, Colo., 48. Mosquito range, Leadville, Colo.: faulting, 48. uplift. 16. Mother Lode district, Cal.: gold-deposits, 811. Mounds : deposits from springs, 32. Mount Guyot, near Breckenridge, Colo.: horizontal faulting, 64. Mount Hood : ascent by Arnold Hague, Txxxil. Mount Nickel mine, Blezard township, Sudbury district, Ontario, 497. photomicrographs of ore, 487-488. Mount Rainier: ascent *by Emmons, [xxxi]. Mount Shasta: ascent by King and Em- mons, [xxxi]. Mountain-building: periodicity. 43. Mountain View mine, Silver Cliff, Colo., [140]. Movements: repeated: along fissure- planes, 59. Mullan, John : Report on the Construction of a Militarv Road, 1863, [xxxii]. Munster : gold in sea-water, [193]. Murohison, R. I : age of auriferous rocks, 258. horizon of gold, [ix]. Murrav, A. R. F. : auriferous rocks of Victoria, 163. Murray mine. MeKim township, Sudbury district. Ontario, 500. Muscovite : crystallization from magmas, 609. Nason, F. L. : genesis of iron -deposits, Missouri, 87. National mine, Cripple Creek, Colo., 420. Natural gas : confinement, 313. Natural water-channels : causes. 33. Neihart, Mont. : silver-lead mines, 219. veins, 227, 228. Nelson granite, Rossland, B. C, 495. Neii thorn gold-field, Otago, N. Z. : assays, 184. Nepheline-basalt : Cripple Creek district, Colo., 411. Nephelite-syenite: analysis, 562. Tamaulipas, Mexico, 562. Nevada : Belmont : dike-rocks, 277. gold-production, 440. metallographic province. 619. silver-mining industry, 299. Tonopah : geology, 591. mineral veins, 593. Nevada City, Cal. : gold -deposits, 812. INDEX. 945 New Brunswick : pyrrhotite, 462. New Mexico : San Pedro : ore-deposits, [238]. New Zealand : South Island : geology. 162. Newberry, Cosmo : source of gold, 178. Newberry, J. S. : age of lignitic sandstone at Silver Reef, Utah, [322]. criticism of Emmons's views answered, 4, 19. genesisof Appalachian iron-deposits, [36] selenium in Silver Reef, Utah, sand- stones, 325. theory of formation of solution-cham- bers, 6. Newberry's theory of ore-genesis: criti- cism, 6, 21, 24. Nickel : associates in rocks, 75. distribution in igneous rocks, 751. in basic rocks, 2*5, 2(15. in igneous rocks. 268. in Sudbury pyrrhotites, 466. occurrence, 316. quantity in igneous rocks, 733. relation to pyrrhotite, 455, 461. Virginia, 834. Nick el -deposits : characteristic features. 511. genesis, 75. Sudbury, Ont., 90-91. Nickel-ores : classification, 477. concentration-experiments, 470. Nickel Plate mine, British Columbia, 383. Nickeliferous pyrrhotite : magnetic sepa- ration, 466. theories of origin, 481. Niter-deposits: formation, 115. Nitrates : in mine-waters, 768. reactions in dissolving gold, 776. Norite : Sudbury, Ontario, 480. Norrbotten, Sweden, iron-ores, 672. Norway : island of Bo mm el : igneous rocks, 281. titaniferous iron -ore : concentration in magmas, 72. Nova Scotia : pyrrhotite, 462. Observations on Mother- Lode Gold- Deposits, California (V RICHARD), KJO. Occurrence of Nickel in Virginia i Watson), 834. Occurrence of Stibnite at Steamboat Springs, Nevada (Lindgkex), xxvi, 629-632. Ocher-deposits : Carters vi lie district, Bar- tow county, (Ja., 830. Oddie rhyolite, Tonopah, Nov., 593. Ohineruuri district, N. Z. : vadose country - rock : analyses, 190. Ontario : gold-deposits, 445. pyrrhotite, 4(52. Ontario mine. Utah : structural features of deposit, 60-62. Ophir district, Cal. : gold -deposits, 813. Ore-bearing solutions : source, 11. Ore-bodies: association with eruptive rocks, 697. limited to certain magmas, 716. mode of formation, 720. mode of occurrence, Leadville, Colo., 13. Queen of the West mine, Colo., 63. relations to vein-walls: Gunnison region, Colo., 56. Ore-currents : descent from above, 2. Ore-deposition : aqueous solution, 29. ascending theory, 12, 14, 15. association with eruptive activity, 21. by Ascending Hot Waters (Weed), xxiii, 403-410. by thermal springs, 406. causes, 37, 342. character of receptacles, 30. Chemistry, 305-363. conditions, 24-25, 35, 37. determining factors, 24. differential, 362. Igneous Rocks and Circulating Waters as Factors (Kemp), xxi, 235-250. Ku Shau Tzu, Mongolia, 359. lateral secretion theory, 23-24. process, 342. processes : western Nevada, 616. Principles Controlling (Van Hise), xvii. selective hypothesis, 614. variation in parts of an ore-body, 361. Ore-deposits (see also names of metals) : Alaska, Tread well, 830. along bedding-planes, 35. along contact-planes, 37. along planes of rock -fracture, 39. alteration in situ, 123. ascending theory, 201. bibliography, 837-928. classification, 286. climatic effects on, 120-121. concentration, 83. Cripple Creek District, Colorado : Basaltic Zones as Guides (Stevens), xxiii, 411- 423. definition, 111. depth of alteration in unglaciated regions, 122. Eastern Gold-Belt of North Carolina (Crosby), 834-835. Enrichment of Gold and Rilrer Veins (Weed), xviii. formation : influence of carbonaceous matter, 231. from meteoric waters, 369. fumarolic origin, 240. Genesis (Emmons), xi. 1-25, 300. genetic classification. 366. haloid compounds: formation iu arid regions, 135. in limestone : depth, 7. form, 5. Joplin Region, Missouri (Clerc), 833-834. Kristiania type : permanence in depth, 393. lateral -secretion theory, 82, 83.201. Leadville, Colo. : investigation, 26. levigation theory. 14. magmatic differentiation, 83. materials : source and concentration, 159. Montana : Butte, 55. produced bv successive concentra- tions, 303-304. 1 Near Igneous Contacts (Weed), xxiii, 364-402. occurrence, 53. of con tact-rue tam orphic origin, 369. . of fumarolic origin, 368. of gas-aqueous origin, 368. 946 INDEX. Ore-deposits : of igneous origin, 366. of igneous-emanation origin, 368, 370. open -cavity theory, 4. origin in depth, 84. pneumatolytic origin, 240. primary or original, 28. receptacles: assumptions regarding, 3. Red Mountain, Colo., 21-32. relation to igneous rocks, 253. relations to petrographic provinces : practical considerations, 755. replacement theory : application, 8. rich : factors determining location, 790. secondary concentration : Sudbury, Ont., 90. secondary enrichment, 761, 791, 810 et seq. selective concentration. 79. Silver Cliff, Colo.: genesis, 155. solfataric origin, 85. source and concentration (summary), 82. source of materials, 15, 111. status of investigations, 81. Structural Relations ( Emmons), xii, 26-64. Sudbury, Ontario (Dickson), xxiv-xxv, 455-516. Superficial Alteration (Penrose), 110-138. sulphide secondary enrichment, xvii. Utah, Bingham, 831. Ore-Formation : Osmosis a Factor in (Gil- lette), xxiv, 450-454. Ore-genesis: ascension theory, xiii. lateral secretion theory, xiii. Ore-materials: migration, 123. Ore-minerals : source in eruptive rocks, 2. Ore- regions: association with ores of ig- neous activity, 253. Ore-segregation : definition, 252. Ore-zone: Cripple Creek, Colo.: structure, 413, 414. Ores (see also, names of metals) : deposition contemporaneous with sedi- ments, 256. derivation from magmas, 237. Oregon : gold-production. 436. Origin of Vein-filled Openings in Southeast- ern Alaska (Spencer), Ki. Orphan Belle mine, Cripple Creek, Colo.,422 Osmosis as a Factor in Ore-Formation (Gil- lette), xxiv. 450-454. Osmotic pressure: law, 451. Osmotic separation of metal-bearing so- lutions. 207. Otago. New Zealand : vadoseconntry-rock: analyses, 188. Otago harbor : sediments: examination for gold, 196. Oversight, mine, Cananea, Mexico, 398. Ovifak. Greenland: iron-ore deposit. 72. Owvhee mines, Idaho : gold-production, 410. Oxidation : limiting depth, 118. Oxidized ores, 581. Pachuca district, Mexico: comparison with Tonopah, Nev., 601. Pacos gossan) : definition, 112. Paraelase : rocks, 92. . Paraclases: definition, 40. Paragenesis of minerals : Clifton-Mor- enci district, Arizona, 536. Paris mine, Silver Peak district, Nevada, 627. Park. James : gold in sea- water, [192]. source of ore-materials of Thames dis- trict. N. Z., 164. Pearce. Richard : analyses of gold-ores, [820]. experiments in solution of gold, [763]. r773|. veins of Cornwall, 10. Pearceite ores, Neihart, Montana, genesis, 404. Pegmatite veins. 239. Pegmatites: definition. 275. Penfield, S. L.: pentlandite in Sudbury ores, 470. Penokee-Gogebic ore-deposit: vertical sec- tion, 639. Penrose, E. A. F., Jr.: The Superficial Al- teration of Ore-Deposits, xv, 110-138, [761]. chemical relations of iron and man- ganese in rocks, [795]. distribution of chloride ores. [768]. fissures at Cripple Creek, Colo., 221. formation of silver chlorides in arid countries, 801. manganese in gold-deposits of Cripple Creek. Colo., 819. Pentlandite: formula, 474-475. Lillehammer, Norway, 474. Sudbury, Ontario, 456, 474. Permeability of rocks under heat and pressure, 29. Persberg, Sweden : iron-deposits : map, 667. Petrographic provinces, 737. distribution, 295-299. in the United States, 740. of foreign countries, 741. persistence, 291. Petrographic provinces and ore-deposits: practical considerations, 755. Petroleum: associated with ore-deposits, 344. oxygenation, 308. reducing power, 350, 357. Pharmacist gold-mine, Cripple Creek, Colo., 422, [819]. Philips: deposition of copper from sea- water, 258* Philipsburg, Mont.: gold-deposits, 814. Phillips, J. A.: banded structure in ore- deposits, 57. ore-deposits in vadose region. 171. Treatise on Ore-Deposits, [5, 12]. Phillips and Lewis: ore-deposits, [282] N pegmatite-dikes at Timbarra, New South Wales, 276. Phosphate-deposits: formation, 114-115. Phosphates: in mine-waters, 770. Phosphorus: distribution iu igneous rocks, 749. in Lake Superior iron-ores. 652. quantity in igneous rpeks, 733. Piesoclases: definition, 40. Pilot fault, Leadville, Colo., 48. Pilot Knob, Mo., iron-ores : occurrence, 87. Pirsson, L. V.: radial dikes. 394. Placer-deposits (see also Gold-deposits), 133, 134. INDEX. 947 Placers : distribution in western America, 435. relation to manganiferous gold-depos- its, 805. Plant- remains, Jasper county, Mo., 329. Plasticity of rock -masses, 44. Platinum : association with gold in Urals, 289. distribution in igneous rocks, 753. in basic rocks, 285. in igneous rocks, 269. Plication of rock masses, 44. Pneumatolysis : definition, 205. Pneumatolytic origin of ore-deposits, 240. Pneumatolytic vapors : action, 388. Pocatello mine, Mineral ridge, Nev., 613. Pointer mine, Cripple Creek, Colo., 420. Pontgibaud, France: silver-lead veins, 226. Porphyry : in Norbotten ore-fields, 675. percolation by water, 13. white : Lead vi lie, Colo.: condition and composition, 18. Leadville, Colo.: source of ore-materi- als, 18. Porphyry Dike mine, Rimini, Mont., 221. Portland mine, Cripple Creek, Colo., 419. Posepny, Franz: Genesis of Ore-Depos- its, v, vii, xiii, 86, 171, 696. gold in stratified formations, 200. metals in water of springs, [708]. origin of Sudbury nickel-ores, 485. Potash : quantity in igneous rocks, 732. Pre-Cambrian gold-deposits, 434. production, 435. Pre-Cambrian series of the Lake Supe- rior region, 634. Precious metals: greater abundance in vadose region : cause, 206. Precipitation : circumstances favoring, 30. of mineral solutions: causes, 37. ore-materials : conditions favoring, 35. Pressure : in relation to jointing, 94, r61e in ore-deposition, 2. Pbichard, W. A.: Obsenmtions on Mother- Lode Gold- Deposits, California [ Trans. , xxxiv, 454-466], Notice, 830. Prime, F.: on Appalachian iron-ores, 36. Principles Controlling Ore-Deposition (Van Hisei, xvii. Promontorio Silver-Mine, Dnrango, Mexico (Lincoln), 834. Prophylitic veins : definition, 438. gold-production, 441. Puerticitos mine, Cananea, Mexico, 378, 398. Purapelly, R.: copper of Lake Superior region, xxxviii. genesis of copper-deposits in Lake Su- perior region, 76. Purington, C. W. : ore-deposits of San Juan region, Colo., 818. source of useful metals, 716. Pyrite : as primary constituent of rocks, 203, 212. behavior with carbonate solutions, 409. chemical reactions with chalcocite, [799]. crystallization from magmas, 609. effect on solubility of galena [766]. in eruptive rocks, 70. Pyrite: precipitating-agency, 232. reducing action, 405. reducing power, 352, 357, 358. Pyrolusite: association with gold, 793. Pyroxenes : in rocks of New Zealand : analyses, 167. Pyrrhotite : analyses, 460. composition and formula, 458, 475. Dead wood, S. D., 316. in diorite, 90. origin, 460. relation to chalcopyrite, 513. reducing power, 355, 358. Pyrrhotite-deposits : Rossi and, B. C, 486. Pyrrhotites: associated minerals, 478. classification, 477. geological relations, 477. Quartz: crystallization from magmas, 609. Quartz-porphyry : Cripple Creek district, Colo., 412. Quartz-veins : origin, 275. origin as magmatic segregations, 275. Quartz- Veins of Silver- Peak, Nevada ( Hast- ings), xxvi. 621-628. Quebec : pyrrhotite, 462. Queensland : gold-quartz veins, 282. Queen of the West mine, Ten-mile dis- trict, Colo.: structural conditions, 62. Quicksilver, associated with petroleum, 344. Quicksilver-deposits : alteration, 134. genesis, 79. Mirabel mine, Lake county, Cal., 79. Racine Boy claim: Silver Cliff, Colo., [140]. Radioactive water: analyses, 709. Rainfall run-off, and evaporation : rela- tion in Colorado, 698. Rainy River district, Ontario: gold-de- posits, 445. Ranbome. F. L.: The Geology and Copper- Deposits of Bisbee, Arizona [Trans., xxxiv, 618-642]. Notice, 829. association of gold with manganese, [781]. gold -deposits, Goldfield, Nev., 825. gold -deposits, Mother Lode district, Cal., 811. gold-deposits, San Juan region, Colo., 818. manganese as indication of rich ore, 787. Ransome, F. L., and Lindgren, W.: gold- deposits, Cripple Creek, Colo., 819. Raven mine, Cripple Creek, Colo., 420. Raymond, R. W.: Preface, v. Discussion on The Torsional Theory of Joints, 101-103. charcoal between lava flows, 319. Geological Distribution of Mining Dis- tricts in the United States, [65]. gold -deposits, Summit district, Colo., [823]. King's meridional zones of mineral- deposits, [81], origin of ore-deposits, [242]. Reports on Mines and Mining West of the Rocky Mountains, [764]. Read, T. T.: The Secondary Enrichment of Copper-Iron Sulphides [Trans., xxxvii, 297-303], Notice, 832. 948 INDEX. Real del Monte district, Mexico: compari- son with Tonopah. Nev., 601. Receptacles for ore-deposition : charac- ter, 30. Recrystallization process: San Jose, Ta- rn an li pas, Mexico. 575. Red Cliff region, Colo.: ore-deposits, 36. Red Mountain, Ouray county, Colo.: oc- currence of ore, 831. ore-deposits, 31-32. Red Spruce mine, Cripple Creek, Colo., 429. Reducing action of volatile hydrocarbons, 346. Reducing power of minerals, 347, 357. Reid. J. A.: analyses of vadose waters : Comstock lode. 802. silver-content of mine- waters, 800. Repeated movements along fissure-planes, 59. Replacement-deposits : Rocky mountains. 10. Replacement iron -deposits : Appalach- ians, 36. Replacement-theory : ore-deposit*. 8, 9. Rhodochrosite: reducing power, 358. Rhyolite: near Silver Cliff, Colo., 139, 143, 157. Rhyolite-dacite: Tonopah, Nev., 592. Richthofen, F. von : genesis of Comstock lode, ix, 85. mineralization of the Comstock lode, 598. Natural Classification of Eruptive Rocks, [ix]. production of Comstock lode. 803. proportion of gold to silver in Com- stock lode, 802. Rickard, T. A.: bonanzas in gold-veins, [797]. formation of bonanzas, 761. mineral veins varying with country- rock, 226. ore-deposits of Rico, Colo.. [3301. origin of ores of Bendigo reefs, Aus- tralia, T20H]. reduction of ore-bodies by black shale, 331, 332. solution of gold, 773f. vein-structure. 221. vertical distribution of ores, [407]. Rico, Colo., veins. 226. Ritter, E. A.: The Evergreen Copper- De- posits,Colorado [ Trans., xxxviii, 751-765], Notice, &35. Robertson : analvses of rocks of Missouri, [209]. Rock-flowage : loons and conditions, 711. relation to earthquakes, 712. Rock -fracture : causes, 41. effect on water-channels, 34. Rock -fractures : character and extent, 39. classification. 40. complexity, 92. Rock -intrusions (see Intrusions). Rock -m asses : plication and fracture, 44. rigidity and plasticity, 43. Rocks: changes due to contact m e ta- rn or phi Bm, 384. crystalline: classification, 68. determination of age, 68. Rocks : eruptive : analyses, 705. emissions, 236. geological age, 66. Leadville, Colo.: mode of eruption, 18. source of ore-materials, 15. tests for ore-materials. 16. source of vein -materials, 20-22. Tamaulipas, Mexico, 561. gaseous content, 767. igneous: average composition, 734. central Sweden, 657. origin, 659. chlorine-content, 767. crystallization: order in, 261. derivation from refusion of stratified rocks, 21. determination of age, 67. general chemical composition, 730, 734. geological age, 66. origin, 67, 259. RSle in the Formation of Veins (Kemp), xix. segregation or differentiation, 259. superficial : lack of ore-materials, 20. influence on vein -structure, 217. New Zealand : examination, 167-168. permeability to water, 29. Queensland : examination, 168. salts in waters of non -calcareous, 764. secular decay, 112. sedimentary, at Leadville, Colo.: tests for ore-materials, 16-17. distribution of metals, 254. stratified : derivation from igneous rocks, 21. Victoria ; examination, 168. Rock -segregation : unknown finer laws, 265 Rohn, Oscar: Bullfrog and Kawich dis- tricts, Nevada, 600. Rolker, Charles M.: ore-deposits at Lead- ville, Colo.. 13. 18. Roscoeand Schorl em mer : analysis of sea- water, [195]. Rose. G.: forms of gold from precipitation, 105. specific gravities of gold, 106. Rosenbusch, H.: contact-metamorphic phenomena. 524. Rosita. Colo.: Mines (Emmons), 139-161. Rossi and monzonite, Rossi and, B. C, 495. Rossi and, B. C: pyrohotite-deposits, 486. Rotation in faulting. 102. Roth well, R. P.: charcoal in silver-bear- ing sandstones, 319. Silver Reef district, Utah, 326. Rounding of rock -fragments: origin, 46. Rumbold, W. R.: The South African Tin- Deposits [Trans., xx xix, 783-789.], No- tice. 832-833. The Tin- Deposits of the Kinta Valley, Fed- erated Malay State* [Trans., xxxvii, 879-889], Notice, 832. Rupture : angle of, 104. by shear, 98. torsional : character, 99. Rupture-surfaces, experimentally pro- duced, 97. Russell, Clarence : compilation of analy- ses, 763, 765. Entile: occurrence in veins of Alaska, 586, 587. INDEX. 949 Saline deposits : formation, 115. Salisbury mine, Silver Peak district, Ne- vada, 627. Salt : in sedimentary rocks, 766. Sandberger, F.: derivation of vein-ma- terials, 22. genesis of ore-deposits, 14, 86, 204. Sandstone : chlorine-content, 766. San Jose district, Tamaulipas, Mexico: geology, 559. geological map, 560. ore-deposits, 237. situation, 559. San Jose deposits, Tamaulipas, Mexico : map showing location, 558. San Juan region, Colo.: fissure-faulting, 50. gold -deposits, 818. Sankowsky, Nicholas : compilation of an- alyses, 763, 765. San Pedro, N. M. : ore-deposits, [238]. Savant lake, Ontario : gold-deposits, 446. Saxony : Berggiesshubel ore-deposits, 378. Freiberg : Gottlob vein, 218. Scandinavian Iron-Ores, The Geological Relations of [SjSgren), xxvi, 657-695. Scandinavian lake- and bog-ores : distri- bution and origin, 694. Scheerer:. amount of water in magmas, 608. Schmitz, £. J.: copper-ores in the Per- mian of Texas, 327. Schneider, E. A.: experimental tests on colloidal sulphides of gold, [xxiv]. Schrader and Brooks: quartz-veins in Nome region, Alaska, 280. Schwa rz, T. E.: Features of the Occurrence of Ore at Red Mountain, Ouray County, Colo. [Trans., xxxvi, 31-39J, Notice, 831. Science of Ore-Deposits : Bibliography (Irving, Smith. Ferguson). 837-928. Scientific method of study, 70. Scotland : Sutherland gold-fields, 281. Secondary concentration : ore-deposits, 74. Sudbury, Ont., ore-deposits, 90. Secondary enrichment : Copper-Iron Sul- phides (Read), 832. criteria for recognition, 791. gold-deposits, 761. of metals, 785. ore-deposits, 326. sulphide ores, xl. Secular contraction of earth's crust, 42. Security-Geyser mine : Silver Cliff", Colo., 142. Sedimentation : agency in producing water-channels, 33. Sediments : aggregate thickness, 22. Segregation of igneous rocks: laws, 261. Segregation of rock materials : cause, 260. Selenium : mode of occurrence, 326. occurrence in Silver Beef, Utah, sand- stones, 325. relations to igneous rocks, 754. Selwyn, A. R. C.: auriferous rocks of Vic- toria, 163. Se'narmont : synthetic experiments, [2]. Sentinel mine, Silver Peak district, Ne- vada, 626. Serpentine : metamorphic origin, 75. Sewell, H.: silver-ore associated with coal, 321. Shale: oxidation, 536. Shaler, N. S.: origin of limonites, 124. Shales: chlorine-content, 766. Sheeting of country-rock, 46, 47. Shuler, D. P.: magnetic separation of nickel-ores, 469. Siderite : reducing power, 358. Silica : in mine-waters, 770. quantity in igneous rocks, 732. Silver : association with gold, 182. assays, [17], 161. determination of small amounts in sea- water, 829. distribution in igneous rocks, 752. in assays of California rocks, 301. in mine-waters, 800. in rocks of New Zealand, 170. in sea-water, 191. native : in Lake Superior district, 76. precipitation by black shales, 331. removal by solution, 116. salts: reactions, 115. tests for : in rocks at Lead vi lie, Colo., 16-17. Silver City district, Idaho: comparison with Tod o pah, Nev., 601. Silver Cliff, Colo.: country-rock : assays for silver, 161. investigations of country-rocks, 23. Mines (Emmons), xvi, 139-161. mines in rhyolite : geology, 139. ore-deposits : genesis, 155. silver-mines : production, 141. surface-deposits, 140. Silver Cliff and Cripple Creek ore-depos- its compared, 158. Silver-deposits: alteration, 131. association with eruptive rocks, 80. Colorado: Silver Cliff region, 157. Bassick mine, 158. Ben Eaton mine, 157. Bull-Domingo mine, 158. Democrat mine, 157. genesis, 155. Summit district, [823]. concentration, 80. New Mexico, Lake Valley : genesis, 835. Silver-gold and gold-silver ores : vertical relations in deposits, 799. Silver-gold deposits : associated minerals, 825. Nevada: Tonopah, 824. Silver-gold mines (see also Gold-silver mines) : Mizpah, Tonopah, Nev., [825]. Montana-Tonopah, Tonapah, Nev., [825]. Silver-gold ores : Comstock lode, Nev., 800. Silver-Islet mine, Lake Superior, 231. gas-flows, 346. Silver-lead deposits : Colorado : George- town and Silver Plume, 816. in dolomitic limestone, 1. Silver-lead-gold deposits: Leadville, Colo., 815. Silver-lead mines, Neihart, Mont., 219, 220. Silver Ledge, Mercur district, Utah: origin, 290. Silver-mine : Mexico, Durango (Promon- torio), 834. 950 INDEX. Silver-mine waters: salts in, 764. Silver-ore: Lead ville, Colo., 800.* Mineral ridge, Nevada: genetic rela- tions, 613. mode of occurrence, Silver Cliff, Colo., 140. Neibart, Mont., 800. Silver Cliff, Colo.: treatment, 141. Silver-ores of West: origin, 136. Silver Peak, Nevada: geology and ore- deposits, 622, gold-deposits, 813. ore deposits: origin, 628. Quartz- Vein* (Hastings), xxvi, 621-628. Silver Peak quadrangle, Nevada: geol- ogy, 603. mineral veins, 607. Silver Beef ore-deposits, 36. Silver-salts : solubilities, 800. Silver-veins, Butte, Mont., 223, Silvestri, O.: copper in volcanic fumes, 721. Similkameen type of ore-deposits, 383. Sinter : analyses, 149, 629. Sinters: Gevser mine, Silver Cliff, Colo., 148. Sjogren, A.: iron -ores of Taberg, Sma- land, 681. Sjogren, Hjalmar: The Geological Re- lations of the Scandinavian Iron- Ores, xxvi, 657-695. Skarn : definition, 657. Skolar : formation, 669. "Slickenside"-surfaees : fissures, 45. Slickensiding: in joints, 93. Smith, Alexander : chemical reactions in solution of gold, [777]. chemistry of manganese, 780. Smith, H. D., Irving, J. D., Ferguson, H. G. : Bibliography of the Science of Ore- Deposits, 837-928. Smith, George: The Garnet Formations of Chillagoe Copper- Field, North Queens- land, Australia [Trans., xxxiv, 467-478], Notice, 830. Smith, J. Alden : deposition of ores by ascending solutions, 12. Smyth, R. Brough : gold-fields of Vic- toria, 171. Soda: quantity in igneous rocks, 732. Soda mine, Silver Peak district, Nevada, 627. Solfataras: source of ores, 84. Solution chambers: formation, 5. Solutions : r61e in ore-deposition, 2. Some Fractical Suggestions Concerning the Genesis of Ore- Deposits (Boeumer), 829- 830. Songbird mine; Silver Cliff, Colo.? [140]. Sonstadt, E.: gold in sea-water, 192. methods of detecting gold in sea-water, 193. Sonstadt's solution : disadvantages, 166. Soret's principle of cooling solution, 67. Soret's principle of molecular flow, 260. South African Tin-Deposits (Rumbold), 832-833. Southern Klondike district, Nevada, ore- deposits, 618. Spaltenverwerfungen (fissure-faults) : def- inition, 41. Spencer, A. C: Geology of the TreadweU Ore-Deposits* TreadweU Island, Alaska [Trans., xxxv, 473-510], Notice, 830. The Magmatic Origin of Vein-Forming Waters in Southeastern Alaska, xxvi, 582-589. The Origin of Vein-Filled Openings in Southeastern Alaska [Trans., xxxvi, 581-586], Notice, 831. TreadweU gold-mines, Alaska, [811]. Sperrylite: in diorite, 90. Sudbury district, Ontario, 463. Spherulites : Silver Cliff, Colo., 140. Spring waters : analyses, 706. Spriugs : Nevada region : source, 597. production, 33. SPURR, J. £.: A Consideration of Igneous Rocks and their Segregation or Differen- tiation as Related to the Occurrence of Ores, xxii, 251-303. Genetic Relations of the Western Nevada Ores, xxvi, 590-620. convection currents in magmas, 260. differentiation in igneous rocks, 261. gold -deposits, Silver Peak, Nev., [813]. magmatic differentiation, 722. metal lograpbic provinces, 7.56. ore-deposits of Silver Peak quadraugle, 621. silver-gold deposits, Tonopah, [824]. Spurr and Garrey : ore-deposits of George- town, Colo., 8i6, 817. Spurr, Garrey, and Ball : silver-lead depos- its, Georgetown and Silver Plume, Colo., [816]. Stall berg mines, Sweden : plan, 664. Standard mine, Bodie, Cal.: vein-system, 833. Steamboat Springs, Nevada : ore-deposi- tion, 86. stibnite at, 629. Stelzner: origin of ore-deposits, [2011. Step-faults, Lead ville, Colo., 49. Stern beck, R. von : specific gravity of earth, 715. Stetefeldite, Mineral ridge, Nevada, 614. Stevens, E. A.: Basaltic Zones as Guides to Ore- Deposits in the Cripple Creek Dis- trict, Colorado, xxiii, 411-423. Stevens, Hazard : ascent of Mt. Rainier, [xxxiii]. Stibnite : at Steamboat Springs, Nevada, 629, 631. reducing power, 354, 353. Stobie mine, Blezard township, Sudbury district, Ontario, 499. photomicrographs of ore, 487-488. Stokes, H. N.: action of pyrite and m ar- eas ite, 409. reaction with pyrite in production of chalcocite, 799. solution of gold, 771, 772. Stratification : agency in producing water- channels, 33. Stretch, R. H. : "compression-veins," 221. mineral-veins varying with country- rock, 225. vein-contents and country-rock, 233. Striations : fissures, 45. Stringers: definition, 51. Stroug mine, Cripple Creek, Colo., 419. INDEX. 951 Strontium : distribution in igneous rocks, 747. quantity in igneous rocks, 733. Stutzer, O.: genesis of iron-ores of Nor- botten, Sweden, 678. Styria: iron-deposits: surface-action, 126. Sublimation theory of ore-deposition, 2, 204. Substitution theory: ore-deposits, 8. Subterraneau water : limiting depth, 44. Subterranean waters : Geyser mine, Sil- ver Cliff, Colo., 148. Sudbury district, Ontario : metamorphism, 514. Sudbury, Ontario, nickel-region : miner- als, 456. nickel-deposits, 90-91. geology, 479, 481. nickel-ores : genesis, 477. Ore-Deposits (Dickson), xxiv-xxv, 455- 516. Sudbury mattes: composition, 465. Sudbury ores : assays, 464. origin : microscopical evidence, 497. Suess, Eduard: formation of mineral veins by gaseous emanations, 339.. gold resources of the world, 425. ! hot springs of Carlsbad region, 369. ore-deposits derived from igneous ema- , nations, [368]. origin of ore-deposits, 391. Sullivan, £. C: chemical relations of iron and manganese in rocks, 795. experimentation on copper-iron sul- phides, 832. Sulphates : effect on solution of gold, 772, 775. in mine-waters, 766. solution and precipitation of mangan- ese by, 795. Sulphide secondary enrichment : ore-de- posits, xvii. Sulphides : alteration, 2. deep: formation, 183. in rocks, 163. secondary : definition, 183. Sulphur : distribution in igneous rocks, 750. quantity in igneous rocks, 734. reducing power, 307, 351, 357. Sulphuretted hydrogen: reducing power, 352, 357.. Summary of Lake Superior Geology with Special Reference to Recent Studies of the Iron-Bearing Series (Leith), xxvi, 633- 656. Summit district, Colo.: gold-deposits, 822. Summit gold-mine, Cripple Creek, Colo., [819]. Sunrise gold-mine, Macetown, N. Z.: assays, 184. Sunrise mine: Silver Cliff, Colo., [140]. Superficial Alteration of Ore-Deposits (Pkn- rose), xv. Surface-alteration : varying depths, 121. Surface-waters : definition, 6. varying action on ore-deposits, 116. Sutro, A.: genesis of Comstock lode, x. Svartvik mines, Swedeu : section, 665. Sweden : map of ore- province, 658. titaniferous iron-ore: concentration in magmas, 72. Swedish iron-deposits : lake region : con- centration, 127. Syenite : in Norbotten ore-fields, 675. treatment for isolation of hornblende, 165. Synclases : definition, 40. Taberg, Sweden, iron-district : map, 683. Taberg mines, Sweden: origin of iron- ores, 668. Tel lu ride type of ore-deposits, 372. Tellurium : relations to igneous rocks, 754. reducing power, 358. Temperature: increase with depth, 246. of descending column of water, 245. of fluid magmas, 724. rate of increase in earth's crust, 713. Ten-Mile district, Colo.: investigations of country-rocks, 23. ore-deposits, 36. Tephrite : Cripple Creek district, Colo.: 412. Tertiary gold-deposits, 438-441. Tertiary volcanic rocks, Tonopah, Nev., 591. Tetrahedrite : reducing power, 358. Thames district, N. Z. : vadose and deep vein-gold : assays, 185. Thermal springs : ore-deposition, 406. Thompson mine, Cripple Creek, Colo., 420. Thomson, J.: chemical properties of gold, 107. forms of gold from precipitation, 105. Thorium: distribution in igneous rocks, 749. Thunder Bay, Canada, silver- veins, 231. Tibbey, B.: hydrocarbou-gas in Illinois mine, Montana, 346. Tiberg, H. V., iron-ores of Sweden, 665, 669. Time in geologic operations, 700. Tin : distribution in igneous rocks, 753. in siliceous rocks, 285. Tin chloride test for gold, 194. Tin-deposits : Alaska, Cape Prince of Wales : geology and mining, 833. alteration, 133-134. Kinta Valley, Federated Malay State* (Kumbold), 832. South Africau, 832. Tin-veins : occurrence, 287. Tinguaite : San Jose, Tamaulipas, Mexico, 565. Tipperary Premier gold-mine, Macetown, N. Z.: assays, 184. Titaniferous iron-ore : concentration in magmas, 72. Norway, 72. Sweden, 72. Titanium : distribution in igneous rocks, 749. Titanium dioxide : quantity in igneous rocks, 733. Tomboy gold-mine, Silverton, Colo., [818]. Tonopah, Nevada: geology, 591. mineral veins, 593. silver-gold deposits, 824. Topography : effect on depth of altera- tion, 120. 952 INDEX. Tornado mine, Cripple Creek, Colo., 420. Tornebohm : iron-ores of Taberg, Sma- land, 681. Torsion : effects, 51. experiments on glass plates, 95 of rock-masses, 45. Torsion-fractures : character, 95. Torsional rupture : character, 99. Torsional Theory of Joints (Becker), xiii, 92-104. Tourmaline : occurrence in ores, 586. Toyabe range, Nevada : ore-deposits, 617. Travers, M. W.: origin of gas in mineral substances, 389. Tread well gold-silver mine, Douglas Island, Alaska, 811, Tread we 11 ore-deposits: Alaska, Douglas Island, 830. Tremolite : San Jose, Tamaulipas, Mexico, 569. Triumph mine. Cripple Creek, Colo., 419. Tungsten in siliceous rocks, 285. Tuollavaara iron-ore deposits : Sweden, 673. Turner, A. T. : Sudbury mattes, 465. Turner, H. W.: field-work in Silver Peak region, Nevada. 604. quartz-veins at Silver Peak, Nevada, 276. Ulrich, G. H. F.: auriferous rocks of Vic- toria, 283. rocks of Otago peninsula, N. Z., 166. Uncle Sam mine, Tintic district, Utah, 339, 340, 343. Underground water : agency in forma- tion of Lake Superior irou-ores, 644. circulation : factors, 237. derivation, 236. direction of flow, 14. Union Belle mine, Cripple Creek, Colo., 420. United States Geological Survey : found- ing, [xxxiii]. Urals: relations of gold and platinum, 289. Uranium : distribution in igneous rocks, 749, Utah, Dry Cailon, Mono silver-mine, 332. Mercur district: gold -production, 437. vein system, 290. Silver Reef: geologic structure, 325. ore-deposits, 322. silver-ore in sandstone, 320. Tintic district ore-deposits, 335-340, 362. Vadose country-rock at different distances from auriferous lodes : examination, 183. Vadose region : greater richness of gold- deposits, 171. Vadose waters, xiv. Valcalde mines, Silver Peak district, Nevada, 626. Vanadium : association with coal, 321. distribution in igneous rocks, 750. in basic rocks, 285. Vanderbilt mine, Mineral Ridge, Nev., 613. Vanderbilt mine : Silver Cliff, Colo., [140]. Van Diest, E. C. and P. H.: Rito Seco gold-deposits, Costilla county, Colo., 447. Van Hise, C. R.: classification of Algon- kian rocks, 69. critical temperature of water, 713. development of rocks of Lake Superior region, 648. fissures at Cripple Creek, Colo., 221. formation of secondary copper sul- phides, 533. genesis of ore-deposits, [252]. iron-ores : origin, 70. magnetite in magmas, 72. meteoric waters, 240. origin of iron-ores of Michigan and Wisconsin, 124. origin of pegmatite, 275. principles of ore-deposition, xvii, [235], 696, [761]. zone of flowage, 699, 711. zone of fracture, 711. Veins: comb-structure, 10. dependence on rock -structure, 217. derivation of mineral contents, 14. frequency, 248. productive : explanation, 718. . relation to trap rocks, 20. view of older geologists as to their nature, 84. Vein-enrichment : by Ascending Hot Waters (Weed), xxiii, 403-410. Vein-fissure: Ontario mine, Utah, 61. Vein-material : source, 53, 161. Vein-materials: derivation from adjoin- ing rocks, 22-24. derivation from eruptive rocks, 19-22. Leadville, Colo.: source, 16. Vei n -structure : influence of rocks, 217. Vein-system : Cornwall, England, [52]. Erzgebirge, Freiberg, Saxony, 52. Standard Mine, Bodie, Cal. (Bbown),833. Vein-systems : age and relations, 290. Vein -walls : structural features, 54. Butte, Mont., 55. Gunnison region, Colo., 55. Vermilion Creek Basin, Wyoming : dia- mond swindle, [xxxiii]. Vermilion iron range: vertical section, 640. Vermilion River, Ontario : gold -deposits, 445. Vesuvianite: San Jose, Tamaulipas, Mexico, 572. Victor mine, Cripple Creek, Colo., 423. Victoria : gold-quartz veins, 282. Victoria mine, Denison Township,Sudbury district, Ontario, 505. photomicrographs of ore, 490. Vindicator mine, Cripple Creek, Colo., 422. Virginia: Virgilina : copper-veins, 220. Vogelsang, H.: petrographic provinces, 737. Vogesitc : San Jose, Tamaulipas, Mexico, 567. Vogt, J. H. L.: chromite in Norway, [268]. con tact- inetaniorphic phenomena, 525. distribution of rare elements, 745. genesis of ore-deposits, [253], 403. genesis of titaniferous iron-deposits of Sweden, xiii. geology of ore-deposits, [222]. iron -ores of Christian ia region, 692. nickel in basic rocks, 295. origin of nickel-ores, 484. INDEX. 953 Vogt, J. H. L.: rare chemical elements, 737. Waters, ascending, 85. secondary enrichment, xxxix source of iron, 205. ' titauiferous iron-ores of Norway, [111]. Volcanic eruptions : sequence in connec- tion with sequence of metalliferous , veins, 288. ( Volcanic gas : analysis, 388. Vom Rath : Elba iron -ores, 8. Von Foullon : Sudbury nickel -ores, 482. Vrang, C. H.: iron-ores of Sweden, 665. Vulcan ism : expiring: cause of ore bodies ' 721. relation to ore-deposits, 239. vein forming by, 704. Wagoner. Luther: The Detection and Estimation of Small Quantities of Gold and Silver [Trans, xxxi, 798-810], Notice, 829. assays of California rocks, 301. petroleum associated with quicksilver, 344. ; Walferdin : temperatures in earth's crust, 714. i Walhalla, Victoria, gold-bearing rocks: analyses, 186. gold in country-rock : curves showing, 192, 193. vadose country-rock : analyses, 186. Walker, T. L. : 8 perry lite associated with chalcopyrite, 463. Sudbury nickel-ores, 484. Wallace mine, near Whitefish River, Ontario, 508. Wall-pyrite : origin and content, 207, 214. Wall-rocks : permeability to solutions, 207. Walls (see Vein-walls). Washington, H. S.: The Distribution of the Elements in Igneous Rocks, xxviii, 726-758. analysis of analcite-tinguaite, 566. analysis of neph elite-syenite, 562. Washoe, Nev.: investigations of country- rocks, 23. Water (see also Mine-waters) : agency in producing breccia, 47. amount in magmas, 608. aualysis, 630. compression, 244. descending : temperature, 245. films : action in joints, 93. G«yser mine, Silver Cliff, Colo.: analyses, 150. in igneous rocks, 262. ingredients, 113. movement in porphyry, 13. oxidizing agents lost in descending, 6. quantity in crystalline rocks, 733. r61e in magmas, 731. stability, 314. underground : direction of flow, 14. limiting depth. 44 circulating in earth's crust: chanuels for, 30. deep -seated, xiv. in mines: analyses, 765, [779]. salts in, 764. silver-and gold-content, [800]. natural, chlorine-content, 767. vadose, xiv. Water-table : definition and characteriza- tion, 788. relation to chemical activity, 738. seasonal variation, 788. Watson, T. L,: Geology of the Virginia Barite- Deposits [Trans., xxxviii, 710- 733], Notice, 834. Lead- and Zinc-Deposits of the Virginia- Tennessee Region [Trans., xxxvi, 681- 737], Notice, 831-832. The Occurrence of Nickel in Virginia [Trans., xxxviii, 683-697], Notice, 834. Yellow Ocher Deposits of Cartersville Dis- trict, Bartow County, Ga. [Trans., xxxiv, 643-666], Notice, 830. Wells: temperatures in, 714. Wells, R. C: reactions in dissolving gold, 777. reactions of manganese compounds, 785. services rendered by, 764. Weed, W. H.: Influence of Country-Rock on Mineral Veins, xxi, 216-234. Ore- Deposition and Vein- Enrichment by Ascending Hot Waters, xxiii, 403-410. Ore- Deposits ffear Igneous Contacts, xxiii, 364-402. Enrichment of Gold and Silver Veins, xviii. form of contact-deposits, 528. mineral vein-formation at Boulder Hot Springs, Montana, [247]. minerals of secondary origin, [792]. secondary enrichment of gold and silver veins, [761], [815]. Weed and Barrell : Elk horn district, Mont., ore-deposits, [239]. Weidman, S.: origin of Baraboo iron- ores, 651, 652. White, David : plant-remains in Missouri, [329]. White Knob Copper Deposits, Mackay, Idaho (Kemp and Gunther), 833. Whitney, J. D.: locus of metalliferous veins, 280. ore-genesis, [viii]. The Metallic Wealth of the United States, [110]. Williams, G. H. : origin of pegmatite, 275. Wilson, A. D.: ascent of Mt. Rainier, [xxxiii]. Winch ell, A. N.: Discussion on A Consid- eration of Igneous Rocks and their Segre- gation or Differentiatimi as Related to the Occurrence of Ores, 303-304. velocity moving through a channel, Wiuchell, H. V.: genesis of chalcocite at Butte, [761]. genesis of copper-ores, 402. origin of iron -deposits of Mesabi range, Minn., 125. pyrite as a precipitant, 232. synthesis of chalcocite, 533. Thunder Bay silver-veius, 231. 450. Water-channels: in eruptive rocks, 33. locus at Leadville, Colo., 13. natural : causes, 33. Water-courses : Geyser mine, Silver Cliff, Colo., 147. "Water-level" : locus, 6. 60 954 INDEX. Winslow, Arthur: Discussion o» Geolo- gical Distribution of Useful Metals in the United States, 86-89. Discussion on The Genesis of Certain Auriferous Lodes, 208, 211. lead- and zinc-deposits of Missouri ,[209], Wisconsin lead-ores, 334. Wolf, T.: volcanic gases, 723. Wollastonite : contorted zones, Durango, Mexico, 578. San Jose, Tamaulipas, Mexico, 570. Wood lying undersea-water: examination for gold, 197. Worthington mine, Drury township, Sudbury district, Ontario, 505. photographs of sections of ore, 493. Wurtz, Henry : solubility of gold in ferric salts, 173. Yankee Girl mine, San Juan region, Colo., example of chimney -deposits, 58,59. occurrence of ore, 831. Yellow Ocher Deposits of Cartersville District, Bartow County, Qa. (Watson). 830. Yttrium : distribution in igneous rocks. 749. Yukon: gold-quartz veins: formation, 272. Yung and McCaffery : ore-deposits of San Pedro district [577]. Zonobia mine, Cripple Creek, Colo., 422. Zinc: distribution in igneou9 rocks, 753. Zinc-blende: effect of pvrite on solubility, [766]. in Geyser mine, Silver Cliff, Colo., 146. Zinc-deposits : alteration, 131-132. Zinc : distribution in igneous rocks, 753. genesis, 77-79. source of material, 77. Virginia-Tennessee region, 831. Zircon : crystallization from magmas, 609. Zirconium : distribution in igneous rocks, 749. quantity in igneous rocks, 733. Zirkel, F.: contact-metamorphic phenom- ena, 525. Zone of cementation, 241. Zone of flowage : effect on open channels, 699. Zones in ore-deposits, 789. in .«* N 1*1--, M 3 2 *!§'&'&&'*:. 