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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 geological 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 fniles to the {forth 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 irregularly 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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