TERRESTRIAL DEPOSITS OF OWENS VALLEY 



715 



affect the fan there. However, no other evidence of diastrophism 

 appears at Carroll Creek. Probably the difference is due to varia- 

 tions in the gradient and size of the two streams in the mountain 

 canyons, at the time the fans were built. The average slope of the 

 fans in the valley at the base of the mountains is about that of the 

 fan of Lone Pine Creek, 6°. The slope is greater along the axes 

 of the fans than in the inter-fan depressions. 



MATERIALS 



The material of the Sierra bajada is not well exposed, but some 

 idea of its upper portion can be obtained. Nothing is known of 



Fig. 5. — The largest bowlder seen in the Sierra bajada. The man is 6 ft. tall. 

 This bowlder lies in the yard of the Cerro Gordo power shanty in Lone Pine Canyon, 

 ih miles from the foot of the mountains. 



that portion lower than 300 ft. from the surface, as there are no 

 cuts so deep, and well-records are lacking. The material may be 

 seen in three sets of places : (1) on the unaltered surface of the plain, 

 (2) on the sides of the shallow channels, and (3) in the walls of the 

 canyons. 



Lithologically, the bajada is composed of material from the 

 granitic rocks of the Sierras, disintegrated rather than decomposed. 

 Its components are bits of granite, rather than crystals of quartz 

 or feldspar. Even the disintegration is not complete, for the mate- 

 rial is commonly coarse. It is clear that the source of the material 

 is the mountains, and that it was removed from the parent ledges 

 mechanically, and transported to its present position by streams, 



