GLACIAL LAKES TAYLOR. 



317 



for the character of the outlet channel at Kirkfield and below shows 

 that it carried the full discharge of the upper lakes for a considerable 

 length of time. Indeed, the principal or upper strand of the Algon- 

 quin group of beaches is remarkably strong and continuous, not only 

 in the southern parts of the basins, but runs on unbroken in the same 

 character far toward their northern sides. If there are parts where 

 this beach was not formed they must be limited to the far north, 

 for it is strongly developed on the high ground north of Sault Ste. 

 Marie, Ontario. Apparently during the time of the making of the 

 upper strand no part of the lake was subject to deformmg or warping 

 influences, and the outlet was at Kirklield. 



Fig. 7.— Isobases of Lake Algonquin. 

 By Frank B. Taylor and Frank Leverett, 1911. (With compilation from other sources.) 



At length, when the ice sheet had almost entirely disappeared from 

 the lake basins, a great movement of differential elevation began to 

 raise the land. This movement afi'ected a vastly greater area than 

 that of the Great Lakes, but withm this area it affected the northern 

 parts most. South of a line runnmg through the middle of the 

 ''thumb" of Michigan (fig. 7) and across the south arm of Lake 

 Huron in a course about S. 68° E. and N. 68° W. and also south of a 

 line running westward across Lake Michigan from a point south of 

 Frankfort, the Algonquin beach was not affected at all by the uplift. 

 This line was a sort of "hinge" line for the movement. Kirkfield, at 

 the head of the Trent Valley outlet (fig. 6), was well within the region 



