

INDEX. 



293 



Page. 



North Star mine, discovery of gold in 27 



faultsin 178 



ores of, character of 86 



section in 177-178 



figure showing '. 177 



shaft of, depth of 106 



later andesite from, analysis of 241, 246 



description of 239-240 



study of 246-247 



rocksin 126,177-178 



veins in 178 



O. 



Oddie, Mount, erosion on 113 



lava from, analysis of 58,60 



rocksof :. 36,49-51,53,60-61,101 



view from 24 



view of 52 



Oddie, T. L., mention of 26 



Oddie rhyolite, age of 50 



character of 49-50 



contact of, section showing 193 



veins at 191-194 



lava from, analysis of 57 



occurrence of 49, 127 



rhyolile from 61 



Oddie shaft, section in, diagram showing 116 



Ohio Tonopah shaft, depth of 106-203 



location of . 202 



minerals in 205 



roctsof 107,202-205 



section near, diagram showing 43 



temperatures in 263-204 



diagram showing 265 



Ordonez, E., on Mexican ores 267-268,273 



on petrographic province 274 



Ore production, amount of --- 26,28 



Ore shoots, origin of 85,119-122,276-278 



Oregon, craters in 82 



Ores, at Tonopah and elsewhere, comparison of.- .. 267-287 



genesis of 261-262 



treatment of - 28 



Ores, oxidized, analysisof _ 92 



Ores, primary, composition of 86-90 



location of 86 



Oxidation, agents of 90 



depth of 22,90 



effects of 90-94 



process of 93-94 



V. 



Pachuca, Mexico, ores of Tonopah and, comparison of 22, 



267-268,273,278 



section at, figure showing 277 



Pachuca Range, character of 267 



veins of 267-268 



Pacific petrometallographic zone, existence of 278-287 



Pah-Ute Lake, deposits of, comparison of Siebert tuffs 



and 70 



Paleozoic limestone, occurrence of 66 



Paragenesis of vein material 104 



Pelee, Mont, plug of 104 



Penrose, R. A. F. jr., on oxidized veins 91 



Peru, rocks of 280 



Petrcgraphic province, extent of 22, 274-275 



Petroleum , use of 29 



Petrometallographic zone. Pacific, existence of 278-287 



Page. 



Phosphorus, alteration of 233-234 



Physiography of region, account of 109-114 



Pinnubaria inaequalis, occurrence of 70 



Pktsburg shaft, data concerning 204 



Planorbis utahensis, occurrence of 67 



Pliocene time, history in 68, 69, 110 



1'olybasite, occurrence of 22,95 



Power, use of 28 



Propylite, definition of 236-237 



Prospects, descriptions of 115-206 



Pseudomorphs, character of 61-62 



origin of 62 



Pyrargyrite, occurrence of 22, 94-95 



Pyrite, character of 88 



occurrence of 22 



relations of siderite and 208 



view of rock specimen containing 208 



Q. 



Quartz, alteration of earlier andesite to 207-209 



analysis of 87 



character of 86 



occurrence of 22 



origin of 22 



Quaternary erosion, sketch of 109-111 



Quinn Canyon Range, view of 112 



R. 



Railroad, construction of 25, 28 



Rainfall, absorption of 107-108 



amount of 112-113 



Ray, fossils near 66-67 



Real del Monte, ores of Tonopah and, comparison of. 267- 



268,273-274 



Red Rock shaft, data concerning 204 



Replacement, veins due to 84-S5 



Reptile elaim, vein on 103 



vein on, section of, diagram showing 102, 103 



Rescue shaft, description of 194 



water in 105 



Rhynlitc, analyses of 57-58,60,64,65 



areas of, diagram showing 46 



character of 21,36-51, S9-SS 



classification of 59-iiO 



fissure veins in 102 



flow brecciation in 102 



hornblende in 62 



occurrence of 21, 36-51 



origin of 22,63 



veins in 22 



Richthofen, F. von, on mineralization 259-260 



on propylite 236 



Rock alteration, changes during, diagrams illustrat- 

 ing 218,234,242,243 



maximum points of, location of 226-227 



of the earlier andesite 207-238 



of the later andesite 238-252 



of the Oddie rhyolite 252 



processes of 207-252 



Rocks, altered, specimens of, analyses of 216 



microscopic description of 213-216 



phases of, diagrams showing 217-218 



study of 217-226 



Rosenbusch, H., on feldspar 233 



on propylite 236 



Rushton Hill, rocksof and near 43,49-50,57,60-61 



