702 C.K, ILENE 
and granites classed as Laurentian, and folded schists and greenstones 
classed as Huronian. 
The Laurentian rocks prevail over a much greater area than the 
Huronian rocks, being seen along the White and Berens rivers, on 
Lac Seul, and on the English and Matawan rivers. They are gneisses 
and granites, the latter in places apparently intrusive in the former, as 
along the headwaters of the Berens River. ‘The granites are occasion- 
ally intrusive also in the Huronian to the south. 
The Huronian rocks are a series of schists, limestones, and water- 
deposited volcanic materials. They occur in two main areas. The 
eastern one is in the vicinity of Clearwater and Woman lakes. The 
eastern boundary of this area has not been defined; to the west, 
the Huronian is in contact with the Laurentian. From the southwest- 
ern part of the area, a belt extends southwest to the vicinity of Shal- 
low Lake. The western area of Huronian occurs in the vicinity of Red 
Lake, and is surrounded by and incloses areas of Laurentian granite 
and gneiss. 
Contacts of the Laurentian and Huronian rocks are described for 
numerous localities. The contacts are “ generally of a brecciated char- 
acter, the gneisses and granites while in a plastic condition surround- 
ing and inclosing the Huronian schists” (p. 40). 
The Huronian rocks are similar in many respects to the Keewatin 
series of the Lake of the Woods and Rainy Lake districts, to the south : 
but the Huronian of the area under discussion includes dark blue lime- 
stone, and conglomerates with jasper pebbles, both very similar to those 
of the typical Huronian area north of Lake Huron, and the rocks are 
accordingly mapped as Huronian. 
The Coutchiching, supposed by Lawson to underlie the Keewatin 
of the Rainy Lake country, is possibly here represented by a small area 
west of Shallow Lake, mapped as Huronian. However, at Gull Rock 
Lake, rocks which still more resemble the Coutchiching of the Rainy 
Lake region are found to be but highly altered Huronian beds in con- 
tact with the Laurentian, which, when followed along the strike, take 
on the general aspect of the remainder of the Huronian of the district. 
GENERAL COMMENTS. 
In the articles by Blue, Coleman, and Dowling the term Laurentian 
is used to cover both the ancient basement upon which the Huronian 
rocks were deposited, and later granitic intrusives, although Coleman 
