INDEX. 



299 



Rocky Mountain*, geology, 9. 

 Zinc ores, 179. 



Rogers, H. D., on geology at Frank- 

 lin Furnace, N. J., 175. 



Rolker, C. M., cited on Colorado iron 



ores, 126. 

 On Silver Reef, Utah, 226. 



Rominger, C., on the Marquette dis- 

 trict, 101, 102. 



Ropes mine, gold, Michigan, 253. 



Rosenbusch, H., cited on succession 

 of rock-forming minerals, 24. 



Rosita, Colo., 212, 213. 



Rothpletz, A., cited on oolites, 57. 



Rothwell, R. P. , on Silver Rt:ef , Utah, 

 226. 



Roxbury, Conn., spathic ore, 91. 



Ruby, Colo., 211. 



Russell, J. C., cited on Clinton ore, 

 97. 



Russia, platinum, 272. 



Sacramento Valley, 243. 



Saguache Co., Colo., 207-209. 



Saline Co., Ark., nickel, 271. 



Salt Lake Co., Utah, 225. 



San Benito Co., Cal., antimony, 259. 



San Bernardino Co., Cal., iron ore, 

 127. 



Sandberger, F., cited on source of 



ores, 25, 



Barite in limestone, 26. 

 On lateral secretion, 30. 



San Diego Co., Cl., iron ores, 127. 



San Emigdio, Kern Co., Cal., anti- 

 mony, 259. 



Sangre de Cristo range, Colorado, 212. 



Sandia Mountains, N. M., 204. 



Sanford Lake, titaniferous ores, New 

 York, 280. 



San Joaquin Co., Cal., 266. 



San Juan Co., Colo., 205. 

 Bismuth, 260. 



San Juan Mountains, 205. 



San Juan region, Colorado, 205. 



San Luis Obispo Co. (Cal.) chromite, 

 261. 



San Miguel Co., Colo.. 206, 245. 



Santa Fe Co , N. M., 204. 

 Placers of, 245. 



Santa Rita, N. M., copper mines, 150, 

 151. 



Santa Rita Mountains, 203. 



Saucon Valley zinc mines, Pennsyl- 

 vania, 174, 175. 



Schmitt, A., on Missouri iron ores, 



118. 

 On replacement theory as applied 



to Missouri iron ores, 33. 

 On zinc mines of southwestern 

 Missouri, 167. 



Schapbach in the Black Forest, veins 



at, 31. 

 Schooley's Mountain, N. J., iron ores, 



281. 

 Schuyler copper mine, New Jersey, 



153. 



Sebenius, U. , on Adirondack titanif- 

 erous ores, 280. 



Sedimentary rocks defined and rough- 

 ly classified, 6. 



Forms assumed by, 10, 11. 

 Segregated veins, as applied to mag- 

 netite, 281. 



Described, 60. 

 Senarmontite, 259. 

 Sevier Co., Ark , antimony, 259. 

 Shasta Co., Cal., chromite, 261. 

 Shear zones, defined, 13. 

 Sheet of igneous rock, defined, 11. 

 Shepherd Mountain, Mo., 116. 

 Shumagin, Alaska, 254. 

 Siderite, iron ore, 86-91. 

 Siegenite, Mine la Motte, Mo., 271. 

 Sierra Co., Cal., iron ore, 126. 

 Sierra Nevada, chromite, 261. 

 Sierra Nevada in California, 241. 



Recent geological history, 282. 

 Sigmoid fold, defined, 11. 

 Silliman, B., on gold quartz, 248. 

 Siluro-Cambrian limomtes, 276. 

 Silver and gold, mode of occurrence, 



199. 200. 



Silver belt of Utah, 275, 

 Silver Bow Co., Mont., 220. 

 Silver Bow Creek, Butte, Mont., 136. 

 Silver, California, 242. 

 Silver City, Idaho, 223. 

 Silver Cliff, Colo., 212, 213, 

 Silver Islet, Lake Superior, vein il- 

 lustrating lateral secretion, 31. 



Literature, 31. 



Mines, 201. 



Silver King mine, Arizona, 228. 

 Silver minerals, 200. 

 Silver Plume, Colo., 214. 

 Silver Reef, Utah, 154, 226. 

 Silverton, Colo., 207. 

 Silver, Washington, 239. 

 Slayback Lode, New Mexico, 204. 

 Slickensides or slips, defined, 18, 19. 

 Smyth, C. H., Jr., on Clinton ore, 97. 

 Smithfield iron mine, Colorado, 126. 

 Smuggler Mountain, near Aspen, 



Colo., 189. 

 Snake River, Idaho, basalt, 222. 



Placers, Idaho, 245. 

 Socorro Co., N. M., 204. 

 Sonora, Mex., antimony, 260. 

 South Dakota, lead-silver ores, 191. 



Geology, 216. 



