214 T. C. CHAMBERLIN — GLACIAL STUDIES IN GREENLAND. 



points by congelation, but not, I think, by the flowing of crystallized 

 particles over each other while in their crystalline condition. 



Relation of the Glaciers to their Debris. 



The northern glaciers afford little that is new respecting lateral and 

 medial moraines, and they may be neglected. It has already been seen 

 that much basal material is carried in the lower layers of the ice. It 

 was also a matter of frequent observation that debris lies under the ice. 

 Apparently the ice sometimes pushes this along and sometimes slides 

 over it. At the end of the glacier the debris within the ice is freed by 

 melting and accumulates as a talus-slope. This sometimes protects the 

 basal layers from melting, and they become at length incorporated in the 

 growing accumulation. Their subsequent melting gives rise to one form 

 of kettle-holes, but only one form. It appeared from the stages presented 

 by the several glaciers that where a glacier is slowly advancing the 

 talus-slope gradually grows forward and constitutes an embankment 

 upon which the glacier advances. It thereby grades up its own path- 

 way in advance. On seeing this process one is at no loss to understand 

 how ice can advance over fields of sand or soil without in any way dis- 

 rupting them. It buries them before it advances upon them. A large 

 number of the glaciers of the Inglefield region rest upon embankments 

 or pedestals of this kind. Some, which have retreated, have left these 

 exposed to observation. (Figure 13, plate 9.) 



Where the frontal material accumulates in a large mass it opposes 

 such a degree of resistance to the ice that its layers are curved upward 

 on the inner slope, and if the glacier subsequently advances the ice rides 

 up over the moraine. Several such instances were observed, but none 

 was seen where the ice showed any competency to push even its own 

 debris, in notable quantity, in front of it. The ice is weaker than the 

 moraine as a whole. 



Wind-drift Border. 



Not only is the ice of the north Greenland glaciers weak when tested 

 by the resistance of its own frontal moraine, but it is even weak when 

 compared with the wind-drift accumulations of snow on its front. There 

 is a very notable wind-drift phenomenon connected with the border of 

 the great ice-field of north Greenland to which Lieutenant Peary was the 

 first, I think, to call attention. The winds of the great ice-cap flow 

 chiefly down its slopes, as though by direct control of gravity. They 

 carry great quantities of snow, and this lodges in the lee of the terminal 

 moraine. The border-drift thus formed has a breadth of from 1,000 to 



