454 



INDEX. 



i'age. 

 Hematite, features of - 182 



Hematitic specular iron ore, occurrence of 67 



Heni'y, Alexander, citation from, on travels in the 



Northwest - --- 63 



Highest point in district, location of 34,35-86 



Hitchcock, Edward, cited on schist conglomerates 



of Vermont - 170 



Houghton, Douglas, geologic work in Lake Superior 



region done by 64 



Hunt, T . Sterry , Animikie series named by 374 



Huronian group, components of 76, 80-81, 88, 89-90 



Hiironian quartzite, relations of -. - 93 



I. 



Iddings, J. P., citation from, on crystallizations in 



acid lavas 143 



on lavas of Yellowstone Park -- 142 



Igneous intrusions, periods of -. 437-447 



Indian reservation in the district, location of 20,54 



Indians in the district, number and character of... 20,54 



Ingall,E.D., citation from,on Animikie series 396 



on Logan sills - 408 



Intrusive rocks in Duluth gabbro, occurrence and 



character of --- 422-424 



Iron-bearing carbonates, analyses of 380 



Iron-bearing formation, age of 195-196,200 



banding of - 188-190 



beltsof -— 195-196 



characters of 22 



clastic rocks associated with 212 



deposits at bottom of 223-224 



deposits within 224-227 



greenstones associated with 196 



inclusions of, in greenstones . . _ 197 



interbedded volcanic greenstones with 196 



macroscopic characters of - - 181-183 



microscopic characters of 185-188 



origin of.. -. 188-191 



relations of, to adjacent formations. - . 197-198, 207-208 

 unconformity between Ogishke conglomerate 



and 307 



Ii'on Lake, Duluth gabbro at -. 403 



Iron Mountain Lake. See Ensign Lake. 



Iron-ore deposits, age of ._ 232-234 



character of - - 101-103, 113, 127-128, 183-185 



distribution of 78-79 



geologic horizons and relations of... 96-97,127-128,215 



historical sketch of exploration of 213-215 



localitiesof ...-.— 67,96-97 



methods of mining _-. 234-241 



origin of 78-79, 95, 100, 101-103, 227-234 



prospecting for, mode of. 24.3-246 



Ironoi'es, analyses of... - 385 



character of... 101-103,113,183-185 



coarseness of 185 



copper minerals in 184 



iron content of 184 



methods of mining 234r-241 



phosphorus content of 184 



production of.... 241-243 



shipments of 215,241-243 



silica content of 184 



Iron oxide bodies in Duluth gabbro, analyses of 420 



character of 420-422 



Irving, E. D., citation from, on Animikie series... 74,396 



on Archean formations of Minnesota 77-78 



on Cambrian and pre-Cambrian formations. 89-90 



Irving, E. D., citation from, on copper-bearing 



rocks 73-75 



on Huronian group 80-81 



on iron-bearing schists 74 



on iron ores of Lake Superior region, origin 



of. 78-79 



on Logan sills 408 



on relations of Duluth gabbro to Kewee- 



nawan series 407 



geologic work in Vermilion district done by 30 



Irving, E. D., and Van Hise, C. E., citation from, on 



Animikie slates 396 



on Gunflint beds 379 



on iron ores, origin of 328 



on mica-schist at Enghsh Lake 350 



cited on Penokee iron-bearing series 97, 390 



J". 



Jasper, brecciation of 194-195 



color of 182 



folded and contorted, plates showing 176, 178 



relations of, to greenstones 200-210 



unhanded, occurrence of 197 



Jasper Lake, spherulitic greenstones at and near 142, 



148,168 



iron-bearing formation at, relations of 208-209 



jasper interbanded with greenstone at 192-193 



Jasper Peak, heightof 86 



jasper at. 211 



Soudan formation at ■. 173,175 



Kawishiwi Eiver, coui-se and character of 40-41 



conglomerates, metamorphosed, near ....316-317 



dikes along - 357 



gabbro near 93,407 



granite along and near 363-364,355,357,359-860,407 



greenstones near 118 



ellipsoidal, near 169 



metamorphosed rocks along ... 316-317,340-341,359-360 



rotks of various kinds near 108 



Kawishiwin, name proposed 91 



Kawishiwin agglomerate, character of 104 



Kawishiwin greenstone, age and geologic relations 



of -. 91-118 



Kawishiwin rocks, components of (note) 131 



See also Ely conglomerate and Soudanf ormation. 



Keewatin series, age of. 106-107,114 



Kewatin series, characterof 96,106-107,114-115 



deposition of, conditions of 91 



ii-onores of, mode of origin of 95 



origin of .- .- 88,93 



relations of 87,105,114^-115 



• stratigraphic place of 91-92,100,106-107 



Kekekabic, Kekekebic, Kekequabic. See Cacaqua- 



bic. 



395 



Keweenawan dolerite, relations of Rove slates to . 



Keweenawan gabbro, metamorphism of slates by. 342-344 



relations of, to Cacaquabic granite 368,869 



to Giants Eange granite... t. 357-358 



to Gimflint formation 389-390 



to Knife Lake slates 307-308 



to Ogishke conglomerate 307-308 



to Eove slates 395 



to Snowbank granite 



-S'ee also Duluth gabbro. 



