596 WILLET G. MILLER AND CYRIL W. KNIGHT 



province. This is apparently chiefly due to less erosion having 

 taken place, especially prior to Timiskamian time, in the south- 

 eastern section than in the others. Over the northern and north- 

 western areas the Grenville was eroded until only comparatively 

 small remnants in most localities were left. Later erosion, and 

 intrusions, especially the Algoman, have also assisted in destroying 

 the Grenville. However, the broader, more extensive areas of the 

 series in the southeast can be connected, by tracing outliers from 

 point to point, with the exposures in the north and northwest, 

 where occur Timiskamian and Animikean rocks. 



Coleman has described a comparatively large area of Grenville 

 rocks, seven or eight miles southeast of the town of Sudbury, whose 

 relations to the Timiskamian, his Sudbury series, he has deter- 

 mined.^ The Grenville here consists of cyrstalline limestone, quart- 

 zite, and various schists and gneisses, while the Timiskamian con- 

 tains quartzites, greywackes, and other sediments. The Grenville 

 series is profoundly metamorphosed. The Timiskamian, on the 

 other hand, while often schistose and resting in highly inclined 

 positions, has suffered much less metamorphism than the Grenville. 

 There can be no doubt that the two series near Sudbury are sepa- 

 rated by a great discordance and that the Grenville is vastly older 

 than the Timiskamian. Similar relationships are found in other 

 locahties in most of which the Grenville is represented by only 

 very small outliers. 



Near the eastern end of Lake Kipawa, Quebec, which lies not 

 far distant from the foot of Lake Timiskaming, there is an area 

 of Grenville, consisting of crystalline limestone and other sediments. 

 These rocks, described by the senior author in 1901, have been 

 much disturbed by an intrusion of granite, apparently of the same 

 age as that of Lake Timiskaming, on the eroded surface of which 

 lie the fragmental rocks of the Cobalt series, Animikean.^ 



It would thus seem that the authors are justified in correlating 

 the rocks of southeastern Ontario with those to the north and north- 

 west. They have no doubt as to the relations of the Grenville to 

 the Keewatin which occurs in large volume in the southeastern part 



^ Ont. Bur. Mines, XXIII, 208-9. 



^ Am. Geologist, January, 1901; Ont. Bur. Mines, XIII, 102. 



