54 THE JOURNAL OF GEOLOGY. 



The northern end of the Sierra Nevada has since been raised at 

 least 4,000 feet, and possibly as much as 7,000 feet, and a fault 

 of over 3,000 feet developed along the eastern face of that por- 

 tion of the range. The Klamath Mountains may in some por- 

 tions have experienced at the same time an equal upheaval. 

 From all sides the amount of uplift decreased rapidly toward 

 the Sacramento valley. 



In the initial part of this revolution the earlier quartzose aurif- 

 erous gravels were formed. The source of their material was 

 found in the thick deposits of residuar}^ detritus which had 

 accumulated upon the surface of the land during the baselevel 

 period. This large accumulation of disintegrated rock sub- 

 stance rendered the loading of the streams so easy that when 

 rejuvenated by orogenic movements they became overloaded and 

 filled their ancient channels with auriferous gravels. "^ 



J. S. DiLLER. 

 U. S. Geological Survey, Washington, D. C. 

 December 12, 1893. 



' Since this paper was written a very important one has been published by Prof. 

 A. C. Lawson, on the Post-Pliocene Diastrophism of the Coast of Southern Calfornia. 

 University of California, Bulletin of the Department of Geology, Vol. I., No. 4, 

 pp. 1 15-160. 



