CURRENT PRE-CAMBRIAN_ LITERATURE Ii 
overlying Huronian schists as eruptives, of later age than at least the 
earlier members of the Huronian. If this were done, very little of 
the territory under consideration could be mapped as Laurentian 
—perhaps none of it with certainty. However, the discrimination 
may not be made until more detailed work has been done in the 
district. 
Coutchiching mica-schists and gneisses, though probably present, 
have not been certainly recognized. The series of eruptives, pyroclas- 
tics, and less common waterworn clastics, Lawson’s Keewatin, is of 
widespread occurrence, and of great importance as containing the 
gold-bearing veins of the district. It is spoken of under the general 
term Huronian. 
Blue* sketches the geological history of the New Ontario, which 
includes that part of the province of Ontario lying beyond the Mata- 
wan and French rivers, and the Nipissing, Huron, and Superior lakes, 
to the north and west boundaries of the province. Laurentian and 
Huronian rocks form highlands which in Archean time were the most 
important physical feature of North America, sweeping in a curve 
through what is known in our time as the regions of Labrador, Quebec, 
Ontario, and the Northwest Territories. While there are large areas 
in which eruptive masses of granite and gneiss have penetrated the 
Huronian rocks, and thrown them into folds, proving their later age, 
in general the reverse is the case, the Huronian resting unconformably 
upon the Laurentian, and being of later origin. The Huronian is over- 
lain unconformably by Cambrian rocks, under the Cambrian being 
included Animikie, Nipigon, and Potsdam rocks. 
Comments.— The term Camérian, as here used, covers Animikie, 
Keweenawan, and Potsdam rocks. The two former have ordinarily 
been regarded as pre-Cambrian. 
Dowling’ reports on the geology of the country in the vicinity of 
Red Lake and part of the basin of Berens River, in the district of Kee- 
watin, Canada. The rocks exposed are all Archean, including gneisses 
*The New Ontario, by ARCHIBALD BLUE. Fifth Rept. Bureau of Mines, Onta- 
rio, for 1895, pp. 193-196, 1896. 
? Report on the country in the vicinity of Red Lake, and part of the basin of the 
Berens River, District of Keewatin, by D. B. DowLinc, Ann. Rept. Geol. Sury. of 
Canada, for 1894, Vol. VII, Part F, 1896, pp. 54. With geological map. 
