70 THE VERMILION IRON-BEARING DISTRICT. 



WiNCHELL, N. H. First Ann. Rept. Geol. and Nat. Hist. Survey Minn., jDp. 

 129. Second edition, 1884. 



The general distribution of the nonfossil-bearing rocks of Minnesota, 

 referred to as "granitic and inetamorphic rocks" (p. 64), is given in this, 

 the first annual report of the second Minnesota survey. It is stated that 

 they occupy a great portion of the northern part of the State. These 

 rocks are regarded as Laurentian and Huronian. At the time of this 

 publication the great deposits of iron ore, which are now of such national 

 as well as local importance, were but little known, as appears from the 

 indefinite statement that "iron ore in unlimited quantities is said to exist 

 in the dividing ridge between Lake Superior and Vermilion Lake" (p. 67). 



1876. 



Whittlesey, Col. Charles. Ph5'sical geology of Lake Superior: Proc. Am. 

 Assoc. Adv. Sci. , Twenty-fourth Meeting, 1875, Part 2, pp. 60-72, with map, 



Whittlesey finds nowhere on the American side of the boundary, except 

 at Vermilion Lake, rocks which are like the Laurentian of Canada. The 

 great masses of granite and syenite, around which the Huronian is formed, 

 do not resemble the Laurentian of the Canadian geologists. Between the 

 Canadian and American Huronian there is a very close resemblance. The 

 conclusion of Foster and Whitney that the traps of Lake Superior are of 

 Potsdam age is adopted. 



1877. 



Streng, a., and Kloos, J. H. Ueber die krystallinischen Gesteine von Minne- 

 sota in Nord-Ame'rika: Neues Jahrbuch fiir Mineralogie, Geologie, und Paleonto- 

 logie, 1877, pp. 31-56, 113-138, 225-212; translation, by N. H. Winchell, in the 

 Eleventh Ann. Rept. Geol. and Nat. Hist. Survey Minn., for 1882, pp. 30-85. 



The authors state that "the St. Louis River rises in northeastern Minne- 

 sota south of Vermilion Lake, in a region of granite, gneiss, and crystalline 

 slates, which form a branch from the Laurentian formation as it is displayed 

 in the region north of Lake Superior" (p. 36). 



1879. 



AViNCHELL, N. H. Seventh Ann. Rept. Geol. and Nat. Hist. Survej- Minn., for 

 1878. 1879, pp. 9-25. 



In this we find a report by C. W. Hall on a reconnaissance in the 

 northeastern part of Minnesota. In the summary of geolog'ic results (p. 10) 



