Page:The Journal of geology (IA journalofgeology21894univers).pdf/68

This page has been proofread, but needs to be validated.
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 portion of the range. The Klamath Mountains may in some portions 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 auriferous gravels were formed. The source of their material was found in the thick deposits of residuary detritus which had accumulated upon the surface of the land during the baselevel period. This large accumulation of disintegrated rock substance 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.[1]

J. S. Diller.

U. S. Geological Survey, Washington, D. C.
December 12, 1893.
  1. ↑ 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 California.University of California, Bulletin of the Department of Geology, Vol. I., No. 4, pp. 115-160.
This article is issued from Wikisource. The text is available under Creative Commons Attribution-Share Alike 4.0 unless otherwise noted. Additional terms may apply for the media files.