NON-GLACIAL FORMATIONS 



659 



debris \vas carried beyond the ice by the water flowing from it, 

 and deposited in the valleys and "parks," or on the plains below. 

 (iladal cirques, the result of a peculiar phase of glacier erosion, are 



IMS,'. 540. Faulting on the shore of Luke Uonneville. (Church.) 



well developed in many of the glaciated valleys as, for example, in 

 the Uinta Mountains. 



The characteristics of mountain valleys which were occupied 

 by considerable glaciers are essentially constant. They include 

 (i) well developed cirques at the heads (PI. XIII); (2) the upper 

 parts of the valleys were so thoroughly cleaned out by the ice that 

 little loose debris, except that due to post-glacial weathering, re- 

 mains; (3) numerous tributary valleys are hanging (Fig. 151), and 

 their waters form cataracts; (4) at and near the limits of the ice, 



Fig. 541. Fault scarps in the moraine at the mouth of the Little Cottonwood 

 Canyon, Wasatch Mountains. (Gilbert, U. S. Geol. Surv.) 



at stages when its end or edges remained for a time nearly constant 

 in position, there are heavy accumulations of drift, lateral moraines 

 being as a rule more conspicuous than terminal; (5) the valleys 



