﻿474 



SMITHSONIAN MISCELLANEOUS COLLECTIONS 



[vol. 47 



across the valley with a break at the center, most of the blocks being 

 accumulated upon the western side where they attain a height of 40 

 to 50 ft. ( pis. lxv. b, lxvi, a). These blocks are mainly quartzite, are 

 dark and lichen covered and have but slightly disintegrated. What- 

 ever fine material may exist it is entirely overshadowed by the 

 massive blocks thrown tumultuously together. The largest one 



Fig. 78. — Contorted laminae, Wapta glacier. 



observed split in falling and must have originally weighed about 970 

 tons. These also show only rarely signs of glaciation and were 

 carried either on or in the ice and were not carried, or pushed along 

 beneath it. Those blocks upon the eastern side of the valley came 

 from Aberdeen, the Mitre and Lefroy ; those upon the western 

 side were derived mainly from Victoria. The central part of the 

 glacier was not so heavily laden as the sides. No matter how long 

 the ice front should now halt it would be incapable of forming such 

 a moraine. < >ne-quarter mile still farther down the valley there is 

 a double detrital cone which partially covers a triple moraine, com- 

 posed of fine and coarse material, with some till and not differing 

 ntiallv from what is being formed at the present stage of the 

 glacier Mil;. 70). There was a time between the formation of this 

 moraine and the present Mage when the glaciers occupying the head 



