290 



INDEX. 



Contact deposits, 58. 



Copper Basin, Ariz., 151. 



Copper Creek, near Gothic, Colo., 211. 



Copper Falls copper mine, Michigan, 



141. 



Copper Mountain, Ariz., copper dis- 

 trict, 145. 



Copperopolis, Cal., copper mines, 136. 

 Copperopolis copper mine, Utah, 152. 

 Copper ores, analyses of ore miner- 

 als, 134. 



Capper Queen mine, Arizona, 150. 

 Copper, statistics, 155. 

 Cordillera region, general geology, 



27o. 

 Cornwall, Penn., iron mines, 125, 127. 



Literature, 127. 



Costillo Co., Colo., iron mines, 126. 

 Cotta, B. von, on filling of mineral 



veins, 28. 

 Schemes of classification of ore 



deposits, 44-46. 

 Courtis, W. M., on the microscopic 



structure of gold quartz, 249. 

 Cranberry magnetite mines, North 



Carolina, 125. 

 Credntr, H , on origin of Marquette 



ores, 106. 



Creede, Colo., 207-209. 

 Crimora, Va., manganese, 263. 

 Crismon-Mammoth copper mine, 



Utah, 152, 194. 

 Crittenden Co., Ky., lead and zinc 



veins, 166. 



Crosby, W. O., cited on joints, 13. 

 Cross, W., on the mines near Rosita, 



Colo., 213. 

 Crustification, 283. 

 Cryolite, 258. 



Cumberland iron mine, Colorado, 126. 

 Cumberland River region, Kentucky, 



78. 



Curry Co. ore, 240. 

 Curtis, J. S., cited on caves, 21. 

 On Eureka, Nev., 196, 197. 

 On growth of aragonite crystals, 



34. 



On replacement, 33. 

 On silver in quartz porphyry, 25. 

 Caster Co., Colo., 212, 213. 



Idaho, 223. 



Custer mine, Idaho, 223. 

 Dakyns and Teall cited on origin of 



magnetite, 129. 

 Dall, W. H., on Alaska, 253. 

 Dana, divisions of geological time, 4. 

 Davison Co., N. C., lead mines, 157. 

 Dawson, G. M.. on Douglass Island, 



254. 

 Deadwood, S. D., 217. 



Deep Creek mine^, Utah, 225. 

 Deep gravels, California, 24o. 

 Deer Lodge Co., Mont., 221. 

 Deer Trail mine, Utah, 226. 

 De'la Biche, electrical activity of 



veins, 41. 



De Launay, treatise of, 285. 

 Delaware, chrornite, 261. 

 Del Noi-te Co., Cal., chromite, 261. 

 Deloro, Can., arsenic mine, 260. 

 Deloro (Marmora), Can., gold mine* 



256. 

 Devereux, W. B., cited on Colorado 



iron ores, 126. 

 Devonian system at Hamilton, Nev., 



231. 



Diaclases. See under " Joints." 

 Dickerson iron mine, New Jersey, 130. 

 Dike defined, 11. 



Distinction from vein, 11. 

 Cause of earthquakes, 17. 

 Diller, J. S., cited on Kentucky peri- 



dotite, 166. 

 On California, 241. 

 Dillsburg iron mines, Pennsylvania^ 



127. 



Doe Run, Mo., lead mines, 158. 

 Dolomitization, 21, 22. 

 Dolores Co., Colo., 205. 

 Dofia Ana Co., N. M., 181. 

 Douglass Co., Ore., nickel mines,. 



271. 



Douglass Island, Alaska, 250, 254. 

 Drinker, H. S. , cited on the Saucon 



Valley zinc mines, 175. 

 Drumlummon mines, Montana, 221, 



222. 



Dry Canon, Utah, 194, 225. 

 Ducktown, Tenn., illustration of gos- 

 san, 39. 

 Mines of pyrite and chalcopyrite, 



131, 135. 

 Dutton, Capt. C. E. 5 cited on the 



geology of New Mexico, 203. 

 Dyestone iron ore, 92. 

 " Dvestone ranges,' 94. 

 Eagle Co., Colo., 211. 

 Eagle River district, Colo., 186. 

 Earth, average composition of crust, 



72. 

 Eastern sandstone, Keweenaw Point, 



Mich., 139. 



Egan Canon, Nev. , 231. 

 El Dorado Co., Cal., 249. 

 Electrical activity of ore bodies, 235 1 



of veins, 40. 

 Elk Mountains, Colo., 211. 



Iron mines, 126. 

 Elko, Nev., 231. 

 Elko Co., Nev., 232. 



