INDEX. 
Conglomerate, Great, on Porcupine Mountains, 209, 217, 219. 
———-— Portage Lake, 191, 192. 
—, Thickness of, 177, 182, 186. 
—, Inner, Extent of, 215-217. 
, Kingston, 176. 
—, Outer, 151, 179, 186, 
—— on Bad River, 231. 
——on Manitou Island, 179. 
—— — Montreal River, 226. 
——— Porcupine Mountains, 220, 224. , 
——— Potato River, 230. 
——, Thickness of, 186. 
Contact of acid and basic rocks, 148, 432-436. 
—-- at Great Palisades, 147, 314-318. 
——Animikie slates and interbedded diabase, 374. 
—— Eastern Sandstone and Lower Magnesian limestone, 351. 
—— Houronian Quartzites and Cambrian Sandstone at Bara- 
boo, 444. 
—— Keweenawan gabbros and Huronian, at Bad River, 155, 
156. 
—-----— near Bladder Lake, 232. 
—-—-—--— on Saint Louis River, 263. 
—of Keweenawan Series with Animikie Group, 157, 405. 
oo at Grand Portage Bay, 297, 367. 
—— on Thunder Bay, 376. 
a Saint Louis River, 263. 
——-———-— — at Silver Islet Landing, 378, 379. 
—----— Cambrian (Potsdam) sandstone, 366. 
= SS on Kettle River, 244. 
SSS eS at Taylor's Falls, 237. 
———— Eastern Sandstone, 185, 204, 353-361. 
SSS SS on Béte Grise Bay, 353, 354. 
la ms Douglas Houghton River, 355, 356. 
se ae se Gratiot Lake, 354. 
——— — —— — Hungarian River, 354, 355. 
—_-——— in Michigan (T. 50, R. 39 W ), 359, 360. 
===> on Lac La Belle, 354. 
——————-—— Ontonagon River, 203-205, 359, 360. 
SSeS SS Portage Lake, 359. 
---—-— Huronian, 155, 156, 404-408, 
—— —— — —_ in Bad River Region, 155, 156, 231, 232. 
SE at Bladder Lake, 232. 
——-—-—-—-—— Nipigon Lake, 408. 
ee re of North Shore, 405, 406. 
—_— ——— —— South Shore, 404, 405. 
——— Western Sandstone on Douglas County Copper 
P Range, 250-259, 366. 
— —limestone and trap of Nipigon Lake, 369. 
—— sandstone and gabbro on Nipigon Bay, 333. 
———— — Nipigon Lake, 339. 
—— Western sandstone and Saint Louis River slates, 263. 
Copper of amygdaloids, 90, 419-425. 
——, ashbed-diabase, 122. 
——, sandstones, 128. 
— in conglomerates, 420. 
Deposition of, 420-422, 425, 
—, Modes of occurrence of, 251, 419. 
—, Occurrence of, on Douglas County Copper Range, 251. 
———-— Keweenaw Point, 423, 424. 
———— Ontonagon River, 423. 
———-— Portage Lake, 421, 422. 
—, Origin of, 425, 426. 
—, Possible productive area for, 427-429. 
————— in Isle Royale, 420. 
—————— Michigan, 427. 
—, Productive area for, Minnesota, 428, 429. 
451 
Copper, Productive area for, Wisconsin, 427, 428. 
—, Pumpelly on origin of, 425. 
—, Rules for exploration for, 425, 426. 
— in sandstones, 128, 420. 
—, Sulphuretted, in gabbro, 426. 
—in transverse veins, 423, 424. 
Copper Creek, Keweenawan rocks of, 254, 255. 
Copper Falls mine, Sandstone of, 129, 180, 171. 
Copper Harbor, 151, 186, 413, 414. 
——, Dip of strata at, 178, 
Credner, H., Publications of, 20, 21, 22. 
— on relation of Eastern Sandstone and Keweenaw Series, 
363. 
Current River, Diabase-porphyrite near, 375. 
Dacotah Mine, 189. 
Dana, J. D., on composition of anorthite, 440. 
Dawson, J. W., Publication of, 18. 
Delessite of amygdaloids, 90. 
Deroux, H., Publication of, 19. 
Des Cloizeaux on determination of plagioclase feldspars, 39. 
Desor, E., Publication of, 17. 
Detrital Rocks, 127-133, 151. 
——. See Conglomerate, Limestone, Sandstone. 
Devereaux, J. R., 4. 
Devil's Track Lake, visited by Chauvenet and MeKin- 
lay, 273. 
Devil’s Track River (coast near mouth of), Felsite of, 103, 321. 
—— —, Quartz-porphyry of, 149. 
Diabase, Olivine-, (coarse-grained). See Gabbro, Orthoclase- 
free. 
Diabase, Olivine-, (fine-grained), and Melaphyr, 68-77. 
——of Agate Bay, 76, 287. 
——, Alterations in, 70, 71. 
—— of Béte Grise Bay, 74, 185. 
——— Caribou Point, 77, 328. 
——, Characteristics of, 68, 71. 
——, Color of, 69. 
——, Constituents of, 69,70. 
———-—, Age of, 70. 
———-—, augite, 70. 
———-—, magnetite, 70. 
———-—, olivine, 70. 
————, plagioclase, 69. 
————, pyroxene, 70. 
— —, of Eagle River section, 73, 170. 
——— French River, 75, 76, 279, 280. 
——— Gooseberry River, 76, 289, 290. 
——, Graduation of, into coarse olivine-gabbro, 69. 
——, Grain and texture of, 69. 
— —of Greenstone Group, 73, 174, 175. 
—-— — Knife River, 76, 279. 
——— Lac La Belle, 74, 183. 
——— Lester River, 75, 280. 
——— Moose Creek, 75, 247-249. 
——— Porcupine Mountains, 74, 214, 215. 
——— Potato River, 74, 231. 
——, Pumpelly's descriptioa of, 69, 70. 
—— of Silver Creek, 76. 
——, Specific gravity of, 69. 
——near Split Rock River, 76. 
—— of Saint Croix River, 75, 243. 
——— Totogatig district, 75. 
Diabase, Olivine-free, (coarse-grained). 
clase-. 
Diabase, Olivine-free, (fine-grained), 61-68. 
——-—, of Bohemian Range, 67, 183. 
See Gabbro, Ortho- 
