426 DLE OTe NAL TOL GLAOLO GN ls 
represent a portion of the uppermost Jurassic or possibly the very 
base of the Cretaceous. Dr. White has represented graphically 
the position of the different divisions of the California Cretaceous 
in his Correlation papers. According to this the extreme basal 
portion of the Cretaceous is absent. The more recent work of 
Messrs. Diller and Stanton, which has been carried out with the 
greatest care, places the Knoxville at the base of the Cretaceous. 
This places the Golden Gate series in the Jurassic, and probably 
at a horizon which corresponds very closely with that represented 
by the Mariposa beds. Although the fauna at present known 
from the Golden Gate series is indeterminate in its time relations, 
as far as the Jurassic or Cretaceous is concerned, the pronounced 
nonconformity between it and the Knoxville must be taken into 
account. The interval necessary for the deformation, metamor- 
phism and erosion of the lower series must have been consider- 
able, and is to be correlated with that found by Mr. Diller to 
exist between the Upper Jurassic beds of northern and central 
California, and the Shasta-Chico series of the Sacramento Valley. 
The increasing mass of evidence is in favor of the views of Mr. 
Diller concerning the synchronism of the great revolution in the 
Sierras and the Klamath Mountains, which he holds took place 
near the termination of the Jurassic. Accepting this as true, as 
the writer has stated in former publications, a demonstration of 
the extension of this nonconformity southward also proves 
that the underlying rocks are at least as old as the Jurassic. 
THE NONCONFORMITY BETWEEN THE CHICO AND KNOXVILLE IN 
THE SOUTHERN COAST RANGES. 
In several papers the writer has expressed the opinion that 
there is evidence at many points in the Coast Ranges of the 
existence of a nonconformity between the Chico and Knoxville 
beds. This nonconformity is supposed to be due in part toa 
post-Knoxville elevation when numerous bodies of peridotitic 
eruptives were formed. As far as is known the Horsetown beds 
are absent from the Coast Ranges south of. San _ Francisco. 
Until recently the Upper and Lower Cretaceous had not been 
