368 



University of California. 



[Vol. 3. 



of Quaternary time into relief. They bring into equally marked 

 relief the fact that, on the basis of the physical evolution of the 

 region, Quaternary time is divisible into two parts, the earlier 

 of which is many times longer than the later, the demarkation 

 point, between the two being the initiation of the second uplift. 

 If we correlate the earlier subdivision with Hershey's Santa 

 Claran epoch,* as the writer is disposed to do, then the estimates 

 of the writer as to the time ratios of the two main divisions of 

 the Quaternary are confirmatory of those made by Hershey. 



In view of the exceedingly slight post-glacial erosion in the 

 cirques and of the fact that glaciers still linger in the high 

 mountains to the north of the Upper Kern Basin, it appears to 

 the writer that 1,000 years is a reasonable guess at the length of 

 time which has elapsed since the disappearance of the ice from 

 the basin. With this for our unit, the entire duration of 

 Quaternary time would, on the ratios given above, amount to 

 •2, 7.") 1,000 years. 



*Bull. Dept. Geol. Univ. Cal., Vol. Ill, No. 1. 



University of California, 

 December, 1903. 



