RfiSUME OF LITERATURE. 



105 



very w'de personal knowledge of the occurrences described in the articles, 

 and this lends additional value to his opinion. 



The following are his conclusions about the Vermilion district, with 

 which we are especially interested. The succession, compared with that of 

 the Marquette district of the south shore of Lake Superior, which, having 

 been carefully worked out, we can use as a standard, is as follows (p. 195): 



Marquette (Michigan) district. 



AlgonMan 



Archean 



Northern Minnesota 



Keweenawan. 



Unconformity. 



Animikie and Upper Ver- Upper Marquette. 



milion. 

 Unconformity. Unconformity. 



Uower Vermilion. Lower Marquette. 



Unconformity (?). Unconformity. 



(Coutchiching?). 

 Eruptive unconformity 



Fundamental complex (not yet 

 separated in mapping). 



Laurentian. 



Grant, U. S. The stratigraphic position of the Ogishke conglomerate of north- 

 eastern Minnesota: Am. Geologist, Vol. X, 1892, pp. -i-lO. 



Grant states that the Animikie rests unconformably upon the Saganaga 

 granite ; that the Ogishke conglomerate is intruded by the Saganaga granite, 

 and therefore that the Ogishke conglomerate is earlier than and separated 

 by a great structural break from the Saganaga granite. As the Keewatin 

 has the same relations to the Saganaga granite as the Ogishke conglomerate, 

 the same thing is time of the Animikie and Keewatin. 



The Ogislilce conglomerate is younger than the most of Keewatin, but 

 is considered as a part of it. 



1893. 



Van Hise, C. R. An historical sketch of the Lake Superior region to Cambrian 

 time: Jour. Geol., Vol. I, 1893, pp. 113-128. 



In this historical sketch the five subdivisions given for this region are 

 the Basement complex or Archean, the Lower Huronian, Upper Huro- 

 nian, and Keweenawan, the last three together constituting the Algonkian 

 and the Lake Superior (Cambrian) sandstone. Each of these divisions is 

 separated from the others by unconformities. The only rocks of the Ver- 

 milion district treated of are the Lower Vermilion and the Animikie series, 



