

THE GREAT ICE AGE AND SUBSEQUENT FORMATIhnjP 



AT OTTAWA, ONTARIO. 



By H. M. Ami, M.A., F.G.S. 



Continued from Page 7Jf. 



Following this period of great elevation and of extreme cold there 

 came a period of submergence. Nor must it be surmised that the 

 subsidence which took place in this part of the country was necessarily 

 effected in a short time; on the contrary, it must indeed have taken 

 ages for the country to have come down even to the level at which it is 

 at present a height of between two antl three hundred feet above 

 sea level at Ottav/a. As the elevated and ice-bound country 

 was gradually subsiding, there came an amelioration in its 

 climatic condition, and more temperate seasons ensued. The 

 glaciers which at one time discharged their materials into valleys 

 and on land feeders to a regular system of glacial rivers both 

 in the lowlands and in the mountain districts now discharged these 

 along the coast, and coast- ice and icebergs were soon at work as the 

 sea was encroaching upon the land and depositing pver the old beds of 

 the glaciers a series of sedimentary stratti, with which there came 

 also the life and organisms common to siich habitats, so that the next 

 period or formation with which we have to deal is one of marine ongin, 

 deposited in the still depths of an ocean or sea and containing the 

 remains of animals com won to that period in the earth's hi-story. 

 MeanwJiijp, innumerablw quantitifes of icebergs, carrying with them 

 large blocks of rock and detiitus themselves portions of glaciers- 

 were scattering their burden over the bed of this ocean or sea, as the 

 warmer regions were reached, just as is going on at the present day, 



dong the coasts of Labrador, Nawfoundland, etc , the icebergs detached 

 from their northern fortresses sweep down towards the centre of the 



arth no doubt to a great extent duo to Lhab transporting forc3 de- 

 veloped in the rotation of the earth. 



There are certain geologists, I believe, who would account for the 

 striatious in- the hard rock masses below beinsjc formed through the 

 agency of coast-ice and icebirgs only. Whilst admitting the possibility of 



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