HINTZE, GEOLOGY OF WASATCH MOUNTAINS, UTAH 



89 



The main crest line of the Wasatch extends in a general north-south 

 direction and stands at a variable height of from 3000 to 8000 feet above 

 the level of the Bonneville Basin to the west. It is situated near the west- 

 ern border of the block and is marked by a succession of lofty peaks 

 which crown the western terminations of a series of ragged ridges that 

 lead westward from the main divide. This divide is situated from two to 

 six miles east of the crest line, being often nearer the eastern border of 

 the range than the western. This is especially noticeable in the central 

 Wasatch. Here the divide is also lower than the crest by more than a 

 thousand feet. 



FIG. t, STEREOGRAM OF A PORTION OF THE CENTRAL WASATCH MOUNTAINS, UTAH 



Shows a maturely dissected block mountain with a steep western fault face and a 

 gentle eastward back-slope. The main gorges are Big and Little Cottonwood Canyons, 

 heading near the eastern margin of the block, and representing principally obsequent 

 stream channels. 



To the east, a similar series of ridges and intervening gorges lead off 

 from the divide. A significant difference is to be noted here between the 

 slope of the tops of the ridges east of the divide and those to the west. 

 East of the divide, the ridges slope down to the level of high-lying basins, 

 while westward they rise to the crest line and then suddenly break oif to 

 the Salt Lake plain. The tops of the ridges from the crest eastward 

 descend gradually to the divide, and, crossing over it, they continue to 

 become lower until they reach the eastern valley levels. They thus indi- 

 cate the original back slope of the block, though they do not preserve any 

 of the undissected upland surface. The present eastward slope of the 

 ridge tops is not a very noticeable feature when viewed from the high 

 peaks on the crest, the inclination being but a few degrees and appearing 

 almost horizontal to the eye. From the more rapid erosion that has been 

 going on along the crest line, however, it is safe to infer that the original 

 back slope was of greater inclination, probably as much as 10 or 15 

 degrees. 



