The Dawn of Canadian History | Page 5

waters of the inland sea, these waters have narrowed into great rivers--the Mackenzie, the Saskatchewan, the Mississippi--that swept the face of the plateau and wore down the surface of the rock and mountain slopes to spread their powdered fragments on the broad level soil of the prairies of the west. With each stage in the evolution of the land the forms of life appear to have reached a higher development. In place of the seaweed and the giant ferns of the dawn of time there arose the maples, the beeches, and other waving trees that we now see in the Canadian woods. The huge reptiles in the jungle of the Carboniferous era passed out of existence. In place of them came the birds, the mammals,--the varied types of animal life which we now know. Last in the scale of time and highest in point of evolution, there appeared man.
We must not speak of the continents as having been made once and for all in their present form. No doubt in the countless centuries of geological evolution various parts of the earth were alternately raised and depressed. Great forests grew, and by some convulsion were buried beneath the ocean, covered deep as they lay there with a sediment of earth and rock, and at length raised again as the waters retreated. The coal-beds of Cape Breton are the remains of a forest buried beneath the sea. Below the soil of Alberta is a vast jungle of vegetation, a dense mass of giant fern trees. The Great Lakes were once part of a much vaster body of water, far greater in extent than they now are. The ancient shore-line of Lake Superior may be traced five hundred feet above its present level.
In that early period the continents and islands which we now see wholly separated were joined together at various points. The British islands formed a connected part of Europe. The Thames and the Rhine were one and the same river, flowing towards the Arctic ocean over a plain that is now the shallow sunken bed of the North Sea. It is probable that during the last great age, the Quaternary, as geologists call it, the upheaval of what is now the region of Siberia and Alaska, made a continuous chain of land from Asia to America. As the land was depressed again it left behind it the islands in the Bering Sea, like stepping-stones from shore to shore. In the same way, there was perhaps a solid causeway of land from Canada to Europe reaching out across the Northern Atlantic. Baffin Island and other islands of the Canadian North Sea, the great sub-continent of Greenland, Iceland, the Faroe Islands, and the British Isles, all formed part of this continuous chain.
As the last of the great changes, there came the Ice Age, which profoundly affected the climate and soil of Canada, and, when the ice retreated, left its surface much as we see it now. During this period the whole of Canada from the Atlantic to the Rocky Mountains lay buried under a vast sheet of ice. Heaped up in immense masses over the frozen surface of the Hudson Bay country, the ice, from its own dead weight, slid sidewise to the south. As it went it ground down the surface of the land into deep furrows and channels; it cut into the solid rock like a moving plough, and carried with it enormous masses of loose stone and boulders which it threw broadcast over the face of the country. These stones and boulders were thus carried forty and fifty, and in some cases many hundred miles before they were finally loosed and dropped from the sheet of moving ice. In Ontario and Quebec and New England great stones of the glacial drift are found which weigh from one thousand to seven thousand tons. They are deposited in some cases on what is now the summit of hills and mountains, showing how deep the sheet of ice must have been that could thus cover the entire surface of the country, burying alike the valleys and the hills. The mass of ice that moved slowly, century by century, across the face of Southern Canada to New England is estimated to have been in places a mile thick. The limit to which it was carried went far south of the boundaries of Canada. The path of the glacial drift is traced by geologists as far down the Atlantic coast as the present site of New York, and in the central plain of the continent it extended to what is now the state of Missouri.
Facts seem to support the theory that before the Great Ice Age the climate of the northern part of Canada was very different from what it is now. It is very