THE PLEISTOCENE OR GLACIAL PERIOD. 



461 



Bonneville time. Since the Bonneville stage, too, there has been fault- 

 ing in the basin (Figs. 541-542). At the west base of the Wasatch 



Fig. 541. — The trough in the middle foreground was produced by faulting; near 

 the mouth of Little Cottonwood Canyon, Utah. The trough is in glacial drift. 

 (Gilbert, U. S. Geol. Surv.) 



range, faulting has affected the Bonneville terraces, with displace- 

 ments of as much as 40 feet. At other points where post-lacustrine 

 faulting has been observed, the throw is less. 



Fig. 542. — Fault scarps in the moraine at the mouth of the Little Cottonwood Canyon, 

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



The diastrophic activities of the region have not been confined 

 to faulting. The shore lines of the former lake have been deformed 



