Aii Unique -Region 183 



rocks, and crystallized into the granitic rocks (quartz mon- 

 zonite and allied rocks) which, uncovered by erosion, now make 

 up a large part of the range. 



further Uplift, Faulting and Erosion 



At a later time, probably during the Quaternary period, 

 another upheaval occurred by which the Inyo range was 

 brought to its present height. Erosion in the long lapse of 

 time since has caused the removal from great areas of the over- 

 lying roof rocks that were uplifted by the great batholith. 

 Thus the granitic crystalline rocks of the great batholith are 

 exposed now at the surface. Metamorphism by the great heat 

 and pressure of the intruded molten rocks transformed the 

 sedimentary rocks, as sandstone to quartzite, shale to slate, and 

 limestone to marble. 



The eastern and western walls of the Inyo range are very 

 steep and rugged, fault planes or zones of faulting marking 

 both slopes. The western wall of Owens Valley is the great 

 fault scarp of the Sierra range, higher and more rugged than 

 the east wall, that of the Inyo range. The great scarp of the 

 Sierra rises from 3,600 feet in the vicinity of Lake Owens to 

 14,500 feet in Mount Whitney. The average height of the 

 Inyo range is about 10,000 feet. The fault walls or scarps on 

 both sides of the valley are deeply scarred by erosion, and allu- 

 vial deposits of vast extent border the sides of the valley against 

 the bases of the two ranges. Those on the west side of the val- 

 ley are more extensive, forming a nearly continuous plateau 

 abutting the foot of the scarp. On the east or Inyo side of the 

 valley the alluvial cones or outwash from the mountain gullies 

 extend far up the ravines, spreading out below as great alluvial 

 fans or aprons, but not forming a continuous plateau as on the 

 west or Sierra side. The precipitation is less on the Inyo range 

 than on the Sierra, owing to the fact of the greater height of 

 the Sierra and the robbing of the clouds of their moisture as 

 they are carried by the winds eastward from the Pacific Ocean. 



