NATURAL HISTOKY, TORONTO REGION 



The region is not one of high relief, the most ele- 

 vated points to the south not exceeding 850 feet and 

 to the east or north within 100 miles probably not 

 going beyond 1,200. The highest point in the penin- 

 sula between the Great Lakes rises to something over 

 1,700 feet near Dundalk, 76 miles northwest of 

 Toronto. Lake Ontario is 246 feet above the sea, 

 Lake Erie 572 feet and Lake Huron 581. 



Although the variations in elevation are moderate 

 there is great variety of surface features, including 

 gently sloping lacustrine plains, rolling uplands, and 

 an escarpment which crosses the region from south 

 to north with a sudden rise of 300 or 400 feet. It 

 has adjoining it some of the greatest lakes in the 

 world, as well as many smaller bodies of water, and 

 it is well watered with streams of every dimension 

 up to Niagara River, some, like the Thames or Grand 

 River, with gentle, meandering flow, and others with 

 rapids or waterfalls having a sheer leap of 160 feet. 



Except in the Archaean portion to the north the 

 rocky structure is uniform and undisturbed, the beds 

 of sedimentary rocks dipping very gently to the 

 southwest without folds or faults or interruptions by 

 eruptive rocks. 



From middle Palaeozoic times to the present, & 

 far as known, the region has been dry land excep 

 where lakes have covered it owing to Pleistocen 

 shif tings of level or to the damming of valleys by ic 

 masses. The most dramatic episodes in its histor 

 are the advances and retreats of the continental ic 

 52 



