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University of California . 



[Vol. 3. 



into the granitic magma, and that in the Kaweah Peaks we have 

 probably another such area, or, possibly, an extension of the 

 Mineral King belt. The Kaweah Peaks area, however, appears 

 rather to be sessile upon the granite than sunk down into it, 

 although this is questionable. 



These facts suggest that over the granitic terrane of the 

 Upper Kern Basin the original upper surface of the batholith 

 may not be very far above the present actual surface, and that 

 the two may, in places, be even coincident, the present surface 

 being in such a case merely the original upper surface of the 

 batholith stripped of its covering by the usual processes of 

 denudation. Such a contact plane between a batholith and its 

 roof would constitute a structural feature of no mean importance 

 in the degradation of the region; and the possibilities of this 

 control are considered in a subsequent portion of the paper. 



Jointage. — In many parts of the Upper Kern Basin the granite 

 of the region exhibits a pronounced jointage. This structure is 

 best displayed in the walls of the glacial cirques in the higher 

 parts of the mountains, and is less abundantly developed in the 

 walls of the deeper canons. In eases where horizontal jointage 

 prevails there may often be seen distinct and striking differences 

 in the spacing of the joint planes in a vertical range of a few 

 hundred feet, on a cliff face. Near the top of the cliff the joint 

 planes are close together and the joint blocks thin, while lower 

 down they are more widely separated and the blocks thick. 

 Similar differences in the spacing of joint planes have been 

 observed by the writer in other parts of the Sierra Nevada, as 

 for example in the walls of Yosemite. Such horizontal jointages 

 are usually traversed by others approximately vertical, breaking 

 the rock into more or less rectangular prisms or slabs. In other 

 cases the granite has a sheeted or lamellar structure, due to the 

 dominance of a single system of nearly vertical jointage. This 

 is finely exemplified in the cirques about Mt. Whitney, where 

 the sheets are thin and remarkably even from the top of the 

 cirque walls to the bottom. But the direction of this vertically 

 sheeted jointage is not constant over wide areas. In the cirque 

 southwest of Mt. Whitney its strike is roughly east and west, 

 while in the cirque northwest of Mt. Whitney its direction is 



