232 



GEOLOGY 



valleys, and is the offspring of mountain snow-fields. The former 

 type, confined chiefly to high latitudes, are polar or high-latitude 

 glaciers (Fig. 189); the latter are alpine glaciers (Figs. 190-192). 

 The end and side slopes of high-latitude glaciers are, as a rule, 

 much steeper than those of alpine glaciers. 



When a valley glacier descends through its valley to the plain 

 beyond, its end spreads. The deploying ends of adjacent glaciers 



4* 



Fig. 188. New snows of the Cascade Mountains, Washington. 



sometimes merge, and the resulting body of ice constitutes a pnd- 

 mont glacier (Fig. 193). Piedmont glaciers are confined to hiuh 

 latitudes. In some cases the snow-field that gives rise to u ,<r!acicr 

 is restricted to a relatively small depression in the side of a mount ain, 

 or in the escarpment of a plateau. In such cases the snow-fid' I 

 and glacier are hardly distinguishable, and the latter descends l.ut 

 little below the snow-line. Such a glacier, nestled in the face of 

 a cliff, has been called a cliff glacier 1 (Fig. 194). Cliff iilariers an- 

 often as wide as long, and are always small, and between them 

 1 Jour, of Geol., Vol. Ill, p. 888. 



