GLACIERS 



205 



is often disposed unevenly, so as to occasion hilly belts and 

 undrained depressions (Fig. 226 and Plate XII). The trans- 

 porting agent, therefore, gathered its load from an area 



FIG. 215. Section of unstratified drift near Henry, Illinois. (Crane.) 



FIG. 216. Shows the accumulation of drift beneath an existing glacier. 

 Extremity of the lower Blase Dale Glacier of Disco Island, Greenland. 

 (U.S. Geol.Surv.) 



B. & B. GEOL. 12 



