MILLER 



irORK OF GLACIERS 



12; 



or scarcity of sharp angled rocks, and cirques. How is he to rec- 

 ognize glacial erosion in other regions? A trip to a region con- 

 taining rock exposures such as rock hills but not rock valleys 

 will convince him that the facts already learned can be applied. 

 In traveling over such a region, however, he observes that the 

 rock hills have a gentle slope on the side from which the glacier 

 came ( stoss side) and a steep slope on the other (lee) side ( h^ig. 

 2). Wliy do glaciers give this characteristic shape to a rock 

 hill? Are there exceptions? Can this shape be used as a proof 

 to show the direction of ice movement? Can the grooves and 

 scratches be used for the same purpose? are some of the ])r( 

 lems that confront him. 



roD- 



F](;. 3. Rock hill shaped b_v a glacier passing over it from right to left. 



WORK OF DEPO.SITION. 



Let us secure a good view point near the lower end of the 

 same mountain valley where we can look up the vallev and also 

 out upon the plain. How was that semi-circular ridge (Fig. 3) 

 around the mouth of the valley — the tcnniiial moraine — formed? 

 From this position he can form a mental picture of the ice mass 

 that occupied the valley, dei)ositing great quantities of loose rock 



Fig. :\. Terminal moraine around the lower end of valley 

 shown in Fig. l. Both pictures were taken from the same 

 point. 



