REPORT OF THE DIRECTOR 1920-21 85 



fjords, but observations are as yet still very incomplete. As Suess 

 (v. 3, pt 2) points out, Greenland is clearly a part of Laurentia 

 and, as he suggests, the Laurentian Precambrian rocks may extend 

 under the ocean to the western Hebrides. 



While in eastern Ontario, as we have seen, the Precambrian rocks 

 clearly strike northeast and also the later Proterozoic rocks, as the 

 nickel-bearing Algoman and Keweenawan rocks at Sudbury and 

 Cobalt (see Miller and Knight, 19 15 and 191 7, p. 174; also personal 

 information from D. H. Newland; see also Adams, 1915, p. 52) 

 are involved in this folding, as is also well shown in the geological map 

 of the Dominion of Canada published with the Guide book no. 1 ; 

 this direction of folding changes in western Ontario, north of Lake 

 Superior, into an east and west direction. This is again distinctly 

 shown on the above-mentioned map in the strikes of the Lower 

 Huronian beds, and we have it also on personal information from 

 D. H. Newland in regard to the Rainy Lake region. According 

 to Coleman (19 15, p. 135) the Huronian in this, its original, region 

 to the north of Lakes Huron and Superior, has not undergone much 

 deformation by folding. Along the margin of the shield, however, 

 southwest of Lake Superior it has often been subjected to great 

 folding (Coleman, 19 15, p. 136). In the well-known Marquette 

 region a distinct east-west folding has extended to all divisions 

 of the Precambrian (Van Hise and Bailey, 1897); and this general 

 direction holds true southward through the middle of the continent; 

 although local irregularities as the bending of the strikes toward 

 southwest, around the western end of Lake Superior may occur. 

 The Baraboo range in Wisconsin (see Van Hise & Leith, 1909, 

 p. 720) is a great east- west striking syncline, and associated outcrops 

 in Wisconsin, consisting of Huronian and a basement complex 

 considered as Archean, show corresponding strikes. 



The northwestern part of the Canadian shield, west of Hudson Bay, 

 is as yet but very little known. There is, however, no doubt that 

 the Precambrian rocks have there swung into a north-south and 

 northwest direction. This is brought out by the before-mentioned 

 map of Canada and the recent observations of Camsell (19 16) 

 in the Northwest territories. He found, between the Great Slave 

 lakes and Lake Athabasca, the Archean basement complex to have 

 a north and south trend, " corresponding more to the Cordilleran 

 line than to those of East Canada." 1 



1 F. J.. Alcock and E. L. Bruce (Precambrian rocks of Manitoba. Bui. Geol. 

 Soc. 32, no. 2, p. 272, 1921) report a close folding, indicating a northwest trending 

 structure in the Athapapuskow lake area. 



