172 Adventures in Scenery 



Among the high peaks that mark the crest of the High 

 Sierra, and in isolated patches below the crest, occur remnants 

 of the rock formations that were uplifted by the great batho- 

 lith and which formed the roof of the great mountain dome. 

 The first mountain crest above the Yosemite region is the boldly 

 sculptured Clark Range, which terminates in Mount Clark 

 (11,506 feet), on the south side of the Merced. About eight 

 miles farther northeast, between the Merced Basin and the 

 Tuolumne Basin, stands the still bolder Cathedral Range, which 

 extends from Mount Lyell (13,090 feet) northwestward to 

 Cathedral Peak (10,933 feet). The main crest of the Sierra 

 Nevada is surmounted by Mount Dana (13,050 feet) and a 

 long row of other peaks between 12,000 and 13,000 feet in 

 altitude that overlook Mono Lake and the deserts at the east 

 base of the range. 



The largest mass of the ancient roof rocks extends along 

 the western foothills and the lower slope of the range. It is in 

 the remnants of this ancient rock roof that are recognized what 

 have been termed the "roots" of the earlier mountain systems. 

 The rocks are seen to be composed almost wholly of upturned 

 beds of slate, quartzite and marble, inclined at high angles. 

 The slate, quartzite and marble are really shale, sandstone, and 

 limestone originally deposited as mud, sand, and lime that 

 have been metamorphosed by pressure and heat as the beds were 

 folded and pressed together and baked by the intruded molten 

 granite. Intercalated with them are ancient lavas that have 

 been metamorphosed out of all semblance to their former 

 selves. It is interesting to note that cutting northwestward 

 through this belt of metamorphic rocks is a group of gold- 

 bearing quartz veins, the famous Mother Lode of the "days 

 of '49." 



These upturned beds of the lower Sierra slope represent the 

 remnants of a series of closely compressed folds or wrinkles of 

 the ancient rock roof. Strongly bent, folded and closely 

 crumpled strata occur in the canyon of Merced River below 



