No. 1.] GEOLOGY AND MINERALOGY. 49 



GEOLOGY AND MINERALOGY. 



The Mineral Region op Lake Superior. — At the fifth 

 moathly meeting oP the Natural History Society, held on Monday 

 evening last, Feb. 2-4th, Prof. R. Bell, of the Geological Survey 

 of Canada, read a paper on the Huronian and mineral-bearing 

 rocks of Lake Superior ; an abstract of which will be found 

 below. 



In addition to the sandstones of the South shore of the Lake, 

 which are unaltered sediment?, in which traces of organic life 

 have been detected, there are three well-marked groups of rocks 

 •on the Canadian side. These are the Laurentian, the Huronian. 

 and the Upper Copper-bearing series of Lake Superior. Reccat 

 researches have shewn that Huronian rocks occur to a much 

 larger extent than was formerly supposed, as bands alternating 

 with Laurentian beds on both the North and South shores of the 

 Lake. 



To the northward of liike Superior the Laurentian rocks for 

 the most part consist of gray and reddish gneiss, with micaceous 

 belts and mica schists. No minerals of any economic value have 

 yet been found in these rocks, at this particular locality, nor do 

 there seem to be any crystalline limestones. 



In the same region the Huronian rocks are mostly of a schis- 

 tose character, the most common of which are greenish schists 

 and imperfect gneisses, the whole formation being rich in useful 

 minerals. 



A geological map, coloured in conformity with the latest dis- 

 coveries, of the country lying to the north of the lake, and 

 extending from its eastern point as far west as Lake Winnipeg, 

 was then exhibited and explained somewhat in detail, the site of 

 Lake Shebandowan being also pointed out. About two-thirds 

 of this area consists of Laurentian beds, and the remainder of 

 Huronian rocks. 



In these latter deposits almost every conceivable variety of 

 schist is to be met with. Among them are micaceous, hornblen- 

 dic, dioritic, porphyritic, siliceous, cherty, chloritic, felsitic and 

 argillaceous schists ; more rarely dolomitic schists, and occa- 

 sionally bands of magnetic iron ore and haematite. The lecturer 



Vol. VII. D No. 1. 



