THE GLACIER'S SURFACE FEATURES 



399 



ments over the area earlier ice-covered, the terminal moraines are 

 ranged along the vacated valley as recessional moraines, each with 

 a valley train of outwash below. About the apron of the piedmont 

 glacier, such deposits are particularly heavy (Fig. 428). During 



M 



FIG. 428. Ideal form of the surface left on the site of the apron of a piedmont 

 glacier. M , moraine ; T, outwash ; C, basin usually occupied by a lake ; D, drum- 

 lins (after Penck). 



the "ice age " the Swiss glaciers extended down the valleys below 

 the existing ice remnants and spread upon the Swiss foreland as 

 great piedmont glaciers such as may now be seen in Alaska. To- 

 day we find there moraines and glacial outwash, a lake in the 

 middle of the apron site, and sometimes a group of radiating drum- 

 lins like those found within the ice lobes of the continental glacier 

 in southern Wisconsin (Fig. 429, and Fig. 344, p. 317). 





FIG. 429. Moraines and drumlins about Lake Constance upon the site of the 

 earlier piedmont glacier of the Upper Rhine. The white area outside the outer- 

 most moraine is buried in glacial outwash (after Penck and Bruckner). 



