io A. P. COLEMAN 



COUCHICHING IN OTHER REGIONS 



Schists of the Couchiching type are widely found in northern 

 Ontario. They occur at various points on Lake-of-the-Woods, 

 e.g., on the southern edge of the Grande Presqu'isle, and near 

 the Scramble mine east of Kenora, where they are accompanied 

 by a band of granular silica having the look of sandstone. They 

 are found also in large areas near Clearwater and Manitou Lakes, 

 north of Rainy Lake, and extend for miles along the railway east 

 of Dryden, here associated with the iron formation. 



Mica schist or gneiss of the same kind, and also arkose and 

 slate, are found on Sandy and Minnitakie Lakes north of Wabi- 

 goon; so that areas of Couchiching occur for a distance of more 

 than ioo miles north of the Minnesota boundary. 



Within the past year or two similar rocks have been described 

 by E. S. Moore from near Round Lake, north of Lake Nipigon, 

 and by the present writer from Black Sturgeon Lake to the south 

 of Lake Nipigon. 1 In 1908 A. L. Parsons gave an account of 

 schists like the Grenville gneisses on the Algoma boundary 2 and 

 in the following year gray schists of the same sort were observed 

 by myself north of Jackfish and along the shore of Long Lake. 

 The Couchiching here has a width of several miles across the 

 strike, with dips of 6o° or 70 . W. J. Wilson in a "Summary 

 Report on the Algoma and Thunder Bay Districts" 3 describes 

 such gneisses containing garnet, cordierite, sillimanite, etc., as 

 occurring extensively, and compares them with the Couchiching 

 and also with the Grenville gneisses; and W. H. Collins gives an 

 account in the same report of rocks of the same kind southwest of 

 Long Lake, containing garnets and graphite. He mentions quart- 

 zite and arkose as occurring there also. 4 



There are sillimanite gneisses and arkose, as well as ordinary 

 and carbonaceous slate, in various places in the Michipicoten 

 region 150 miles southeast of Long Lake, but the known area of 

 these rocks is not very large. 



Mica schist with staurolite has been found by M. B. Baker in 

 the Abitibi region more than 200 miles to the east, and he men- 



l Bur. Mines (1909), 144 and 158. ^G.S.C, No. 980, 5 and 6. 



2 Ibid. (1907), 101. * Ibid,, No. 1081, 14. 



