GLACIER TYPES OF A WANING GLACIATION 385 



FIG. 410. Map of the Baltoro glacier of the 

 Himalayas, a typical glacier of the dendritic 

 type. 



striae directed in opposite directions from the highest point. The 

 pass of the Grimsel in Switzerland furnishes an excellent illustra- 

 tion of such earlier transection of the range. 



The expanded-f oot glacier. As air temperatures continue to be- 

 come milder, the glacier streams within the mountains are less deep 

 and hence more clearly 

 defined, and instead of 

 coalescing upon the moun- 

 tain foreland, they now 

 issue from the mountains 

 to form individual aprons 

 and are described as ex- 

 panded-foot glaciers (Fig. 

 408, stage II, and Fig. 

 292, p. 264). 



The dendritic glacier. 

 Still later in the hemicycle nourishment of the glaciers is di- 

 minished as depletion from melting increases, so that the glacier 

 streams no longer reach to the mountain front. Branches con- 

 tinue to enter the main valley from 

 the several side valleys like the short 

 branches of a tall tree, and because of 

 this arrangement such a glacier may 

 be described as a dendritic glacier 

 (Fig. 408, stage III, and Fig. 410). 



Inasmuch as the depletion from 

 melting increases at a rapid rate in 

 descending to lower levels, the tribu- 

 tary glacier valleys " hanging " above 

 the main valley in the lower stretches 

 become separated, and may continue 

 to exist as series of hanging glacierets 

 upon either side of the main valley be- 

 low the glacier front (Fig. 408, stage 

 III, and Fig. 411). It must be clear 

 from this that any attempt to name 

 FIG. 411. The Triest glacier, a each separated ice stream without 



hangingglacieretseparatedfrom d t ^ relationship must lead 



the Great Aletsch glacier to .... 



which it was lately a tributary, to endless confusion, for glacier size 



20 



