VOLUME XXX NUMBER 5 



THE 



JOURNAL OF GEOLOGY 



yuly- August ig22 



POST-GLACIAL LAKES IN THE MACKENZIE RIVER 

 BASIN, NORTH WEST TERRITORIES, CANADA 



A. E. CAMERON 



University of Alberta, Edmonton, Alberta, Canada 



It is a well-known fact that lakes or ponds of impounded water 

 would form whenever the retreating continental ice sheet receded 

 down a stream valley. It is therefore evident that the run-off 

 from the eastward slopes of the Rocky Mountain cordillera would 

 be impounded behind the retreating ice front of the Keewatin 

 glacier as it receded, and the lakes so formed would expand laterally 

 along the margin of the ice sheet, and the water would collect both 

 from the inflowing streams and the melting ice until it rose above 

 the lowest point in the stream valley walls, when it would spill 

 over and form a new river course, possibly at considerable variance 

 to the pre-established drainage lines. Thus we would expect to 

 find evidence of ice-dammed lakes of greater or less magnitude 

 throughout large areas in the northern portions of the great plains 

 area of the Dominion of Canada. It is not the object of this 

 paper to deal with the possible extent of such lakes throughout the 

 northern regions, but rather to consider one or two specific stages 

 in the lake expansions as they were apparently developed in the 

 lower Peace and Athabaska river valleys, Athabaska Lake and 

 Great Slave Lake. 



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