INDEX 



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Page. 



Agawa formation, age of -- 33,308,330 



characters of - - 34* 327-328 



distribution of - 324^326 



exposures of ..- — 326,330-335 



origin of --— 329,440 



petrographic characters of. 327-328 



relations of 303,329-330 



stratigraphic position of 33, 308, 329-330 



structure of. --- 326-327 



thickness of — - 330 



Agawa Lake, Agawa formation at 325,329,330,331 



Agriculture of the district, chai-acter of 50 



Ahbe, F., cited on mining methods in Vermilion dis- 

 trict -. 234 



Akeley Lake, Gunflint formation at 25,109-110 



iron-bearing rocks of 109-110 



Logan sills at 411 



Pewataic quartzites at 103-104. 110, 119 



Akeley Lake series, occurrence of 119 



Algonkian period, geologic history of 437-445 



Algonkian rocks, components of - 105 



map showing- 32 



Amphibole-schists derived from greenstones, com- 

 position of 157 



Amygdaloidal greenstones, occurrence of 139-141,165 



plate showing - 168 



Anderson. C. L., and Clark, Thomas, report made 

 by, on geology and, geological survey of 



Minnesota 66 



Annamani Lake (a glacial lake ) , site of 430 



Animikie series, age of 106,114,122,124-125,396 



areas of 25,88,375 



character of._ 25-26, 



74, 88, 96, 97, 102-103, 106, 120-122, 377-387, 392-393 



components of 25,33,88,102-103,109,115,121,374 



deposition, of conditions of 442 



dip of - - 88,109 



divisions of 25,33,88,102-103,109,115,121,374 



equivalents of 80-81,92,118 



exposures of 120-122 



formations composing 25, 33, 102-103, 121 , 374 



metamoi-phism of 25-26, 122, 383-387, 393-394 



relations of, to adjacent formations 84, 



86, SS, 93, 96, 97, 105, 109-110, 114^116, 387-390, 395 



to Hiironian quartzite 93 



to Eewatin rocks 84,88,93,109 



to Logan sills 408-410 



to Vermillion slates 86 



stratigraphic position of 78,80-81,99,106 



thickness of 74,390 



See also Upper Huronian. 



MON XLV — 03 20 



Archean history, sketch of.. 437-439 



Archean rocks, chaz'acter of 95-96,99 



components of 33, 99, 100, 105, 116-117, 129-130, 439 



definition of 1 129-130 



divisions of 129-130 



Ely greenstone of 130-173 



granites of -... 124,246-274 



intrusive rocks of, relations of, to Soudan for- 

 mation 199 



relations of 95,96,281-284 



Soudau formation of 172-246 



Archean history, sketch of.. 437-439 



Area and boundaries of the district 32 



Argentiferous quartz veins near Vermilion Lake, 



occurrence of 67 



Arkose, occurrence of.. 270 



Armstrong Bay, conglomerate at 287 



Armstrong Lake, conglomerate and greenstone at, 195 



rock banding near 195 



Augiteof Cacaquabic granite, analysis of 366 



Am'iferous quartz veins near Vermilion Lake, oc- 

 currence of 67 



Bacon, D. H., acknowledgments to 18,30 



cited on mining methods in VermUiou district , 234 



Banding in Ely greenstone.. 149 



Bass Lake, slates at 336 



Basswood gneiss, stratigraphic place of 89 



Basswood Lake, elevation of 34 



granite at, age of 261 



distribution of 258 



exposures of 258 



folding in ..., 262 



petrographic characters of 259-260 



relationsof 260-261 



topography of 259 



granitoid and gneissoid rocks at 87 



greenstones near , 118 



syenite near 69 



Upper Kewatin rocks at 120 



Bayley, W. S., citation from, on Duluth gabbro_. 402,404 

 on iron-bearing rocks of Gunflint formation . '3Sii 

 on metamorphism of slates by gabbro at 



Pigeon Point, Minn 394 



on petrography and geology of Akeley Lake 



region 103-104 



Bayley, "W. S., geologic work in Vermilion district 



done by 17,30 



Bayley, W. S., Smyth, H. L., and Van Hise, C. E., 



cited on origin of iron ores 23^^ 



449 



