392 OSCAR H. HERSHEY 
nary conditions in California. It is, therefore, reasonably certain 
that the upper portion of the Neocene gravels of the Klamath 
region represents the Upper Pliocene. In short, the alluvial 
filling of the Neocene valleys is probably the chronologic equiva- 
lent of the whole of the Coast Range Pliocene series, with its 
San Pablo, Berkeleyan, and Merced divisions. 
I have correlated in a general way the Neocene baselevel of 
the Trinity valley with the peneplain of the Sierra Nevada 
region, but this requires some qualifications. The latter was 
developed in early Pliocene time and largely buried under 
andesite lava and tuff during the Middle Pliocene time. Then 
it was slightly disturbed and partly resurrected by erosion during 
late Pliocene time. In the Klamath region there were deep 
cafions in the earlier portion of the Pliocene period, and the 
Neocene baselevel reached its stage of maximum development 
at about the close of the period. Then came the great uplift 
which terminated low-level conditions in both provinces. 
Oscar H. HERSHEY. 
BERKELEY, CALIF., 
February 7, 1902. 
