Section IV, 1887. [ 63 ] Trans. Eoy. Soc. Canada. 



VI. — Tlie Correlation of the Animikie and Huronian Rocks of Lake Superior. 



By Peter McKellar. 



(Communicated by Dr. Bell, May 25, 1887.) 



Having had more than twenty years experience, as a practical geologist, among the 

 rocks of nearly every district on both sides of Lake Superior, I may be allowed to offer to 

 the Eoyal Society the results of my studies of the relations which the different formations 

 of these regions bear to one another. A want of agreement has lately arisen among geo- 

 logists, as to the equivalency, or otherwise, of the Ânimikie and the Huronian series of 

 this paTt of the Dominion, and I propose to confine my remarks chiefly to an elucidation 

 of this problem. I think I am in possession of sufficient facts to set at rest any question 

 as to their mutual relations. The term " Huronian " was first applied by Logan and Murray 

 to a set of metamorphic and igneous rocks north of Lake Huron, and the name was soon 

 extended to rocks, similar to the majority of these, on Lake Superior. Sir "William Logan 

 also called the Huronian, the " Lower Copper-Bearing Eocks," and the series of which the 

 Animikie forms the lower part, the " Upper Copper-Bearing Rocks" of Lake Superior. What 

 is considered to be the equivalent of the upper division of this latter series on the south 

 shore of the lake was afterwards called the " Keweeniau " formation by the United States 

 Greologists, the name being derived from Keweenaw or Kewaiwana Point. Logan's 

 names — Lower and Upper groups of the Upper Copper-Bearing Eocks of Lake Superior — 

 were found to be inconveniently long for constant use, and Dr. Bell proposed to call the 

 whole s§ries the " Nipigou " formation, it being extensively developed around Nipigon 

 Lake and the Bay of the same name on Lake Superior. The lower and upper groups of 

 the Nipigon (or Upper Copper-Bearing) formation appeared, from Dr. Bell's descriptions, to 

 be unconformable to one another, and Dr. T. S. Hiint, at the suggestion of the writer, 

 proposed the name " Animikie " for the lower portion — Animikie being the Outchipwai name 

 for "thunder," the formation being well developed around Thunder Bay. The name 

 " Nipigon " would then be restricted to the upper division. The sandstones of Sault Ste. 

 Marie are generally conceded to be newer than any of the formations referred to, although 

 their relations to some of them have not yet been very satisfactorily demonstrated. 

 According to the Canadian geologists, we have therefore, on Lake Superior, the following 

 sets of rocks, in descending order : — 



1. The Sault Ste. Marie sandstones, resting apparently unconformably on the Ke- 

 weenian. 



2. The Nipigon formation, equivalent, at least in part, to the Keweenian. 



3. The Animikie formation, iinconformable to both the Nipigon above and the 

 Huronian below. 



4. The Huronian system. 



