﻿sherzer] 



GLACIAL STUDIES IN CANADIAN ROCKIES 



493 



bare (fig. 9 2 )> ' ,ul the western side is entirely so and we see an ice 

 ride 25 to 30 ft. in height (fig. 93). This exposure of the ice per- 

 mits its rapid melting, even below the level of the ice upon which the 

 two ridges are now resting and instead of the ice ridge we find 

 farther down the valley a depression with a small morainic ridge 

 upon either side. 



5. Block Moraines. — From the outermost of the two block 

 moraines of the lllecillewaet there curves across the mouth of the 

 Asulkan valley a similar type of moraine, made up of identical blocks 

 in the same condition. From their position it is evident, as pointed 



Fir,. 93. — Left Asulkan moraine shedding its rocky covering and exposing the 



ice core. West side. 



out by Penck, that the Asulkan glacier operated conjointly and 

 simultaneously with the lllecillewaet. The bulk of the material is 

 deposited upon the eastern side of the valley and appears to have 

 been derived mainly from Glacier Crest. Lookout Mountain and the 

 Asulkan Range. In retreating up its relatively narrow valley, in- 

 stead of a single prolonged halt, it made two or three minor ones 

 and built coarse moraines, at the same time distributing coarse 

 material along the valley floor. 



6. Rate of Retreat. — From an examination of a number of trees, 

 of the different varieties found in the Asulkan and lllecillewaet val- 

 leys, it was found that the average breadth of an annual ring of 



