454 
Flowage-structure in basic rocks, 81, 139. 
—of Beaver Bay Group, 149, 313. 
—— Great Palisades, 317, 318. 
—— Red Rock Bay, 322. 
Fond du Lae, 26. 
—, Sandstone of, 262. 
Fond du Lac Mine, Olivine-free diabase of, 68, 251. 
Fortieth Parallel, Geological exploration of, 98, 109, 312. 
Foster, J. W., Publications by, 18. 
Foster, J. W., and Whitney, J. D., 2, 5, 6, 197. 
——— on acid eruptives, 12. 
———W— Bohemian Range, 180, 185. 
—— —— conglomerates, origin of, 30, 31. 
—-—- , pebbles of, 31. 
— ——— Eastern Sandstone, 361, 362. 
——— — Isle Royale, 330, 331. 
———— Keweenaw Series, age of, 12, 352, 442. 
—— —— Lake Superior synclinal, 410. 
———— Mount Bohemia, 184. 
os Houghton, 149, 183. 
———— pebbles of conglomerates, 31. 
—— —-- Pigeon Point, 370. 
———— Porcupine Mountains, 207, 224. 
——-—, Publications of, 16, 17, 18. 
——— on Saint Croix Valley, 240. 
———— sandstone of Béte Grise Bay, 185, 353, 354. 
———— South Range, 204, 205. 
—— ——Stannard’s Rock, 197. 
— ——— traps, origin of, 9. 
Fouqué, F., and Lévy, A. M., on secondary quartz, 438. 
French River, 264. 
——, Agate Bay Group on, 284. 
——, Diabase-porphyrite of, 83. 
——, Lester River Group on, 279-281. 
— —, Olivine-diabase of, 72, 76, 280. 
——, Olivine-gabbro of, 281. 
Gabbro, Hornblende-, 5€-58. 
— of Bad River country, 232. 
—, Characteristics of, 56. 
—, Constituents of, 57. 
—, Localities for, 56. 
—, Tabulation of observations on, 57, 58. 
Gabbro, Olivine-. See Gabbro, Orthoclase-free. 
Gabbro, Orthoclase-, 50-56. 
—of Aminicon River. 
——Bad River, 54, 144, 155, 156, 232, 233. 
—— Brunschweiler River, 54, 230, 231. 
—— Cascade River, 56. 
—, Constituents of, apatite, 52. 
——-—, augite, 52. 
——-—, biotite, 52. 
———, copper sulphide, 52. 
—— —, chlorite, 52. 
——-—, iron sulphide, 52. 
———, magnetite, 51. 
———, orthoclase, 51. 
——-—, plagioclase, 51. 
———, quartz, secondary, 51, 438. 
— ——, titanic acid, 51. 
—, Distribution of, 154. 
—, of Duluth, 51, 53, 55, 269. 
—— Eagle Mountain, 56, 273, 274. 
—— Eagle River Section, 53, 174, 175, 176. 
— Frequency of, 50. 
—, Grain of, 50. 
— — Lester River, 55, 981, 282. 
—, Mode of occurrence of, 52. 
INDEX. 
Gabbro, Orthoclase-, of Mount Bohemia, 53, 184. 
— — Pigeon River, 372. 
— — Silver Islet, 378. 
—, Tabulation of observations on, 53-56. 
—of Thunder Bay, 376. 
Gabbro, Orthoclase-free, 37-50. 
—of Animikie Group, 368, 379. 
— — Bad River, 45, 232. 
—— Beaver Bay Group, 48, 49, 302, 308. 
—— Brunschweiler River, 46, 230, 231. 
—— Brulé River, 38, 49, 144, 321. 
—, Characteristics of, 37. 
—, Constituents of, apatite, 43. 
———, augite, 42, 43. 
——— biotite. 43. 
——-—, chlorite, 43. 
—— —, ferrite, 40. 
——-—, iron oxide, 41. 
——-—, olivine, 37, 38. 
——-, plagioclase, 39, 40. © 
——-—, prehnite, 43. 
——~-—, titaniferous magnetite, 41. 
—— -—, viridite, 43. 
—, Distribution of, 154. 
—of Duluth 46, 277. 
—— Eagle River section, 45, 175. 
—— Encampment Bluff and River, 47, 286. 
—, Localities for, 43. 
—, Luster-mottling of, 42. 
—, Mode of occurrence of, 43. 
—of Nipigon Bay, 50, 333, 334. 
—- Pigeon Point, 370. 
— —— River, 371, 372. 
—— Potato River, 45, 230. 
—— Saint Lonis River, 268, 270. 
—, Specific gravity of, 38. 
—of Split Rock River, 49, 302. 
— Tabulation of observations on, 45-50. 
—— Thunder Bay, 371, 376, 277. 
Gaujot, E., on Bohemian Range, 180. 
Geological Report, Copper Lands, &c. See Foster and 
Whitney. 
Glass-base, 96. 
——of felsites, 99, 100. 
Gogogashugun River, Diabase, &c., of, 229, 
——, Quartzless-porphyry of, 93. 
Good Harbor Bay, Sandstones of, 329. 
Gooseberry River, Agate Bay beds at, 289, 290. 
——, Conglomerate on, 293. 
——, Felsite of, 231. 
——, Olivine-diabase of, 76. 
Goose Point, Olivine-gabbro near, 375. 
Grand Falls. See Kakabika Falls. 
Grand Marais and vicinity, Beaver Bay rocks at, 298, 319, 320. 
——~—, Felsite of, 103, 110. 
——v—, Reef at harbor at, 327. 
—-—— Relation of acid and basic rocks of, 436. 
— —, Temperance River Group at, 324, 327. 
——, Titanic acid in rocks of, 52. 
——, Titaniferous magnetite of, 51. 
——, Topography near, 141, 142. 
Grand Portage, 330. 
—— Bay, Animikie Group at, 297, 367, 405. 
———, Gabbros of, 297. 
——— Erosion of Huronian beds at, 405. 
Granite,125. 
— of Bad River, 144, 233, 435. 
sellin iia ita isin ia as insu alia nti alia g pment — Biya 
