RESUME OF LITERATURE. 65 



1852. 



Owen, David Dale. Report of a geological survej' of Wisconsin, Iowa, and 

 Minnesota; and incidentallj^ of a portion of Nebraska Territory. 1852. (Dr. J. G. 

 Norwood's report, pp. 213-118.) 



In 1848 Dr. Norwood ascended St. Louis River, and crossing the 

 divide descended Vermilion River to Vermilion Lake. This portion of the 

 river is now known as Pike River. He then crossed the lake and went on 

 down Vermilion River proper to Rainy River. His observations were not 

 numerous. On the divide, the Missabd Wachu (Big Man Hills) or Giants 

 range, he observed syenitic granite associated with gneiss. As Vermilion 

 Lake was approached, outcrops of slaty hornblende rock, micaceous clay 

 slate, and siliceous slate appeared in the banks and bed of the river, 

 forming riffles and falls. On the south side of Vermilion Lake talcose and 

 mica-slate and micaceous schists were exposed. On the north side of the 

 lake, at the outlet, and continuing on along the outlet, mica-slate and 

 granite were found. He notes that the general trend of the ridges is east- 

 northeast and west-southwest (p. 313). Structiu-ally, he considers the 

 northeast part of Minnesota (p. 333) to consist of northeast-southwest 

 alternating anticlinal and synclinal folds, rivers sometimes occupying the 

 synclinal valleys. A range of greenstone, beginning at the great bend of 

 St. Louis River and running northeast (N. 30° E.), forms a true anticlinal 

 axis, the line of elevation crossing the boundary line between the sources 

 of Arrow Lake and Mountain Lake (p. 336)." 



In 1849 Dr. Norwood followed the international boundary from Pigeon 

 River to Saganaga Lake. He mentions the occurrence of siliceous slate 

 and hornblende and ferruginous rocks on Grunflint Lake, and while the 

 statement is not perfectly clear, he seems to have the idea that these have 

 been disturbed by the intrusion of the granite, which he observed exposed 

 from Gunflint Lake to Saganaga Lake. This granite forms a range which, 

 if continued on the southwest, he states (p. 417) would pass in the line of 

 the Missabi^ Wachu (Giants range) and Pokegama Falls on the Mississippi. 

 He thus implies the correlation of the granite of Saganaga Lake with that 

 of the Mesabi range, a position taken by some of the later geologists, as 

 will be seen below. He commends the northwest shore of Lake Superior as 



« Norwood erred in making this statement, as this axis — the Giants range — crosses the interna- 

 tional boundary between Gunflint and Saganaga lakes. 



MON XLV — 03 5 



