ORIGINAL ICE STRUCTURES IN SANDS 231 



of grains indicate, under extremely variable conditions and in 

 complex relations to unassorted masses. This seems to point to 

 marginal and superglacial accumulation in such relation to the 

 general ice mass that the particles subsequently became incor- 

 porated with it and partook of its later movements. These later 

 movements developed the structures just described which may not 

 have been uncommon in other drift deposits but which are prob- 

 ably seldom so well preserved. 



Although the original ice behavior is indicated by these struc- 

 tures it is doubtful whether the observations are of much value 

 toward a better understanding of ice flowage. The ice must have 

 been unusually heavily saturated with these earthy matters, the 

 sands and gravels, and it is probable that differentia] movements 

 were largely encouraged by their differences of texture. 



