ANCIENT GLACIERS. 



127 



gellan he found great masses of un stratified glacial material 

 containing boulders which were at least one hundred and 

 thirty miles away from their parent rock ; while upon the 



MAP 



OF 



NORTH AMERICA ° 



IN THE 



ICE PERIOD 



By J. S. NEWBERRY. 



Glaciers and^Snow Fields 



Fig. 38.— Generalised view of the whole glaciated region of North America. 

 The area of motionless ground-ice is shown by the white lines in northern 

 part of Alaska. 

 10 



