500 



i:^rDEX. 



Iron oxide of metabasalt 98,99,117,127,131 



of raetadolerite 202 



of muscovite-biotite-gneiss, plate of 298 



of peridotite 252 



of picrite-porpliyry 214,216,218 



of variolites HI 



veins in Gro veland formation i49 



Iron pyrites of basic dikes 47 



of peridotite 252 



Iron Star Co. {See Great "Western mine.) 



Iron Star mine. {See Great "Western mine.) 



Ishpeming formation, correlation of xxv, xxvi 



Irving, R. D., in concretionary structure in feriugi- 



nous cbert 422 



on Felch Mountain range 379-380 



on magnetic mapping - - 24,336 



on mica-schist 414 



on origin of iron ore 70) 71 1 130 



Ivrea, Italy, norite from, analysis of 244, 245 



Italy, norites from 235 



J. 



Jacob's staff, use of, described - 342 



Janesville, N. Y., analysis of slate from 261 



Johnston-Lavis, H. J., on resorption by intrusives. . 227 



Judd, J. W., on basalts 104 



Julien, A. A., on litbology of Crystal Falls district . 21 



on Upper Huronian 173-174 



K. 



Kayser, E., analyses by 207-208 



Kelley, F. T., referred to 22 



Kemp, F. J., analysis of mica-schist 394 



on limburgite 221 



on ultrabasic intrusives 220 



' on picrite- porphyry 219 



referred to 95 



Keweenawan series relations to Cambrian sandstone . 162 



Kona dolomite, correlation of xxv, xx vi 



Erakatao, tuff from 142 



L. 



La Platte Ei ver, olivine gabbro from 255 



Labradorite of gabbro and norite 233 



of hornblende-gabbro 241 



of metabasalt 104,105 



twinning of 104 



Lakes of Crystal Falls district, origin of 32 



Bone, described 35 



referred to 156 



Huron, Huronian rocks of north shore of xvii 



Michigan, streams tributary to 31 



Superior, streams tributary to 31 



Light, described 34 



Liver, described 34 



Mary . , 161 



Squaw 335 



SnuDog 335 



Tobin 164 



Trout 335 



Lake Superior land district, map of, by Foster and 



Whitney 17 



Lake Superior sandstone described 28 



unconformity with Huronian 28 



(See Potsdam sandstone.) 



Lake Superior Survey 183 



Lake Superior Survey, reconnaissance by 329 



topography by 22 



Lamont mine, location of 178, Op. 186 



table of shipments from Op. 186 



{See Monitor mine.) 

 Lamont Mining Company. {See Lamont Mine.) 



Land Survey, United States 23, 343 



Lane, A. C, referred to 21 



Lang, H. Otto, referred to 105 



Larsson, Per, on composition of iron ore 69 



Laurentian. {*S'fie Archean.) 



Lavas, basic, described 95-135 



Lawson, A. C, on ellipsoidal structure 118-119 



on Laurentian and Coutchichiug 380 



Lean ore in Upper Huronian 182 



Lee Peck mine, location of 178, Op. 186 



table of shipments from Op. 186 



Leith, C. K. , indebtedness to 12 



Leucosene of greenstone 470 



of metabasalt 100 



of metadolerite 202 



surrounding magnetite 470 



Lewis, H. C, on saxonite-porpbyry 220 



on alteration of olivine 218 



Lewis, indebtedness to 331 



Life in Mansfield slate, presence of carbon 60 



Light Lake described 34 



Limburgite, porphyritic intrusive, described 212-221 



Lime rock of Mansfield mine 63,67,69,70 



Limestone of Felch Mountain range, Rominger on.. 383 



of hemlock formation .* 153 



,{See Dolomite, Randville dolomite.) 



Llmonite deposits of Upper Huronian 180 



from calcite 153 



from siderlte 168 



of Groveland formation 420 



Lincoln mine 179 



analysis of ore from 181 



location of 178, Op. 180 



table of shipments from Op. 186 



Lincoln Mining Co. {See Lincoln mine.) 



Lindgren, "Waldemar, on granodiorite 231 



Liver Lake described 34 



Long Portage 174 



Long Portage series 173 



Lessen, K., on altered clay slates 206, 209 



Lower Huronian series described x vii, 



. XVIII, 50-154, 398-423, 430-450, 471-481 



erosion of xxi, xxii 



magnetic rocks of, described 338-341 



relations to Archean xix, 55 



relations to intrusives 187,190 



relations to Upper Huronian xvii, 



XXII, 158, 160, 161, 162, 163, 176, 424 



succession in xxv, xx vi, 50 



thickness of xvii 



Lower Marquette series, distribution of 453-455 



relations to Crystal Falls series xxv, xxvi 



relations to Menominee series xxv, xxvi, 451-457 



relations to Sturgeon River series 462 



ore deposits, comparison with Crystal Falls ore 



deposits 181 



Lower Menominee, relations to conglomerate of 



Sturgeon River tongue 473 



relations to Lower Marquette 451-457 



Luster mottling in metadolerite 100 



