NATURAL HISTORY, TORONTO REGION 



perhaps equally vast gap between the middle of the 

 Palaeozoic and the end of the Pliocene is likewise 

 without a record. It is probable that during both 

 great intervals the region was a land surface under- 

 going denudation. What took place during these 

 times can only be inferred from the general geologi- 

 cal history of North America. 



The different formations within easy reach of 

 Toronto will be taken up briefly as given above, 

 beginning with the oldest and advancing to the most 

 recent. 



ARCHAEAN. 



Archaean rocks are exposed ninety miles to the 

 north of Toronto, and may be reached by any of the 

 four northward-running railways, the nearest point by 

 rail being Washago. After passing the boundary of 

 the Archaean the traveller is struck by the change of 

 scenery, rounded hills of reddish gneiss rising irregu- 

 larly above valleys generally occupied by a lake ; for 

 the region stretching two thousand miles to the north 

 of the Palaeozoic border is typical " rocky lake " 

 country, with thousands of rock-rimmed bodies of 

 water, summer playgrounds for the city dweller and 

 tourist. They include the Muskoka lakes and dozens 

 of others less known, as well as the eastern shore of 

 Georgian Bay. 



At the nearest points to Toronto the Archaean 

 consists mainly of Laurentian granite and gneiss, 

 with masses and bands of greenstone or greenschist, 

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