514 
INDEX. 
Page. 
Strong mine, view of.:. 416 
water level in. 240,470-471 
change in, figure showing. 242 
workings of. 466 
Strontia, occurrence of, in vein-forming waters. 220 
Strontium sulphate, analysis of. 126 
description and occurrence of. 125-126,220 
Structure, account of. 2,23-40 
Sulphantimonites, description of. 120-122 
Sulphates, etc., description of. 122-129 
occurrence and source of. 220-221 
Sulphide enrichment, description of. 204 
Sulphides, deposition of. 229 
description of. 120-122,225 
presence of, in vein-forming water. 225 
Summit mine, minerals in. 123 
Sunflower shaft, location and description of. 271 
Sunnyside claim, location of.. 298 
Sunset claim, location of. 330 
Sunset-Eclipse mine, description of. 494-495 
geology of. 494 
minerals in. 122 
ore bodies in... 213 
production of. 494 
veins of. 494 
Sunshine mine, description of. 281-282 
production of. 281 
veins of... 282 
workings of. 281 
Swanson, Walter, data from. 279 
Syenite, abundancy of. Ill 
alteration of. 184,188 
analyses of. 87,104 
area covered by. 110 
composition of. 57,87-88 
description of. 84-85 
intrusions of. 32-34 
minerals in. 85-86 
occurrence of. 2,3,20,21,23,32-34,274, 
291,306-307.374,378,408,416-417,426,430,436-437 
origin of. 56 
petrology of. 85-87 
photomicrograph of. 82 
See also Olivine syenite. 
Sylvanite, composition of. 169 
description of. 116,169 
occurrence of. 4,114,131,169,178,303,307- 
308,311,318,337,341,343,344,360,372,442,475,476 
See also Tellurides. 
Synopsis of paper. 1-10 
T. 
Talbot vein, location of. 423 
Talc, occurrence of. 192 
Tateman shaft, location and description of. 426 
Tayfbr, E. G., vein found by. 355 
Teals tunnel, location of. 495 
Telluride mill, process in, description of. 142 
Tellurides, deposition of. 223-225,229 
description of. 115-118 
derivation of. 224 
occurrence of. 115-118, 
185-193,274,289,312,320-321,337-338,345, 348, 
356, 372, 373, 379,397-402,410 442, 475, 487 
oxidation of. 7,200 
See also Calaverite; Sylvanite. 
Tellurite, description of. 120 
Page. 
Tellurite, occurrence of. 114,120,289 
Tellurium, analysis of. 118 
occurrence of. 6,114,115 
oxidized compounds of, analyses of. 118 
descriptions of. 118-120 
presence of, in vein-forming water. 223-225 
value of. 170 
Temperature, underground, data on. 10,269-270 
Tenderfoot Hill, copper on. 115 
dike on. 32 
prospects on. 151 
Tertiary volcanics. See Volcanic rocks. 
Tetradymite, description of. 116 
Tetrahedrite, deposition of. 225 
description of. 121-122 
occurrence of. 4, 
6,7,114,169,174,175,188,204,212,272,278,286,307-308, 
318-320,327-329,343,353,372-379,391, 402, 411, 414, 418 
Theresa mine, description of. 426 
minerals in. 121 
veins of. 427,428,429 
Theresa East vein, character of. 427,428,429 
Thompson fault, location and description of.... 166,333,334 
Thompson mine, location of. 331 
ore of. 338,341 
workings on. 331,333-334 
Thurlow claim, location of. 322 
Tillery vein, location and description of. 351-352,353 
minerals in. 175 
Tipton, B. F., data from. 256,264 
Titanite, description of. 127 
occurrence of. 49,64,76-77,81,83,86,114 
Titanium, occurrence of. 56 
Topographical map of district. Pocket 
Topography, description of. 147,233 
development of. 36-40 
prevolcanic condition of. 36-38 
figure showing. 37 
Tornado claim, location of. 331 
workings on. 331-332 
Tourmaline, description of. 127 
occurrence of. 114 
Trachydolerite, abundancy of. Ill 
analyses of. 90,104 
area covered by. 110 
description of. 88 -89 
eruptions of. 24 
occurrence of. 2,3,21,34,322,324,387 
origin of. 56 
petrology of. 89-90 
photomicrographs of. 82,94 
texture of. 90 
See also Isabella trachydolerite. 
Trachyte, origin of. 56 
Trachyte mine, description of. 406 
minerals in. 122 
Trachyte Mountain, prospects on... 151,283 
rocks of. 3«, 57 
Trail mine, description of. 370 
dikes in. 370 
ore of. 211,370 
Trilby mine, description of. 369-370 
dikes in. 368,369-370 
location of. 370 
ore of. 369 
production of. 369 
Triumph shaft, location of. 482 
