I:. BELL — GLACIAL PHENOMENA [N CANADA. 



tions of the country east of the Rocky Mountains have been unequalled 

 by any other single traveller, and it is therefore hoped thai some points of 

 interest will be brought out in the following paper. 



The Evidence concerning Repetition of Gold Epochs. — Have we had in 

 North America two or more distinct glacial periods, separated from one 

 another by long interval.-, of time? Thie is one of the Grst questions which 

 arise when we begin to classify our facts and describe the observed phe- 

 nomena. Limited deposits of lignite occur between layers of till, especially 

 in the more southern ami western parts of the drift region, where the ice- 

 Bheel was liable to advance and retreat according as the conditions were 

 more or less favorable for the accumulation of ice during cycles of years. I 

 have found similar deposits as far north as the southern part of Hudson'.- Bay. 

 liut these facts seem merely to indicate temporary and local interruptions of 

 the glacial condition, and do not afford proof of an interglacial period ex- 

 tending throughout North America and lasting long enough to require us to 

 consider thai there were two or more glacial periods wholly separated from 

 one another. On the contrary, it appears as if all the phenomena might be 

 referred to one general glacial period, which was long continued and con 

 quently accompanied by varying conditions of temperature, regional oscilla- 

 tions of the surface, and changes in the distribution of sea and land and in 

 the currents in the ocean. These changes would necessarily give rise to 

 local variations in the climate, and might permit of vegetation for a time in 

 regions which need nol have been far removed from extensive glaciers. 



Geographic Changes of the 1'1'iMocene. — Geological explorations have now 

 been made in all parts of the Dominion sufficient to show that the glaciation 

 of the surface east of the Rocky .Mountains has been universal, except in the 

 northern part of the eastern Labrador range and perhaps in some of the 

 higher parts of Baffinland. It is doubtful also if the Gaspe* peninsula has 

 been glaciated, excepl locally. What was the condition of the now glaciated 

 ana before the commencement of the drift period? 



The relative contours of adjacent districts were probably something like 

 what they are to-day, but regional elevation and depression have made greal 

 differences in the distribution of land and water on a grand scale. Th< 

 changes of level, going on during the progress of the ice a'_ r e. made great 

 alteration.-- in the distribution of the ice-sheets ami in the movements of th< 

 wide-spread glaciers themselves, a- proved by the various courses of the ice- 

 grooves and the different directions in which the drift materials have been 



transported. The latter, alter having been moved in one direction, have in 



some cases been partly carried off in another, owing to a change in the 

 com-.' of tin- ice movement. These changes of movement may have been 

 brOUghl about by an increase or diminution in the Blope of the land or the 



relative elevations of different districts, but probably also largely on account 



