:U2 



GEOLOGY. 



priate), seems to have little orderly arrangement of its parts, yet 

 it often has a sort of rude cleavage which has been called foliation. 



Fig. 476. — Glaciated stones from the drift of northern Illinois. (Photo, by Church.) 



Fig. 477. — Glacially faceted and scratched pebbles, remarkable for the number of 

 planed faces, for the pronounced beveling, etc.; from the Illinois and Michigan 

 canal, Chicago. 



The planes of cleavage are in such relations as to suggest that they 

 were developed by pressure from above. This is consistent with the 



