A(/e of the Cnlifornin Coast. Jinnges. — Fairbanks. 275 
"There is evidence favoring tlie same conclusion in that the thickness 
of the Shasta-Chico series diminishes westward from the Sacramento 
valley into the Coast range, as it does eastward to the base of the Sierra 
Nevada. — The thinning out of the Shasta-Chico series westward from 
the Sacramento valley shows that the Coast range was uplifted at the 
close of the Jurassic, when the Sierra Nevada received its final folding 
and the Great Valley of ('alifornia was outlined thereby. It cannot yet 
be definitely concluded that the Coast range and the Sacramento valley 
originated at the close of the Jurassic ; their beginnings may date from 
earlier foldings; but whatever the date of inception, it is evident that 
during the Shasta-Chico period the Coast range existed, but did not 
furnish sufficient obstruction to keep the open sea out of the Sacra- 
mento valley, for the fossils of that period are everywhere purely 
marine." 
Although the CretJiceous is? found at Avidely separated points 
through the central Coast ranges there is ever}'^ reason to be- 
lieve that much of the region was above water through not 
only the Cretaceous, but also the Eocene. If the Coast ranges 
originated as late as the close of the Miocene how is it possi- 
ble to explain the fact that in different portions the strata 
of this age rest unconforniably on either the Tejon, Chieo, 
Knoxville, Golden Gate series, or the crystalline basement 
rocks, as the case may be? While all the main geological di- 
visions from the Jurassic down appear in the Coast ranges 
they are all rarely present in a single locality. 
The quotation given by Mr. Ransome from Antisell shows 
the limited knowledge of his day, for a little farther along he 
says that the earliest strata brought to light by the Tertiary 
elevation are of Miocene age. 
It is difficult to see the harmony which is stated to exist 
(p. 386) between the quotation from the U. S. Geological Sur- 
vey to the effect that during the Miocene the Great Valley 
was occupied by a gulf, connecting with the ocean by sounds 
through the Coast ranges, and the statement by Mr. Ransome 
that '"the Coast ranges M'ere altogether benejith the ocean, 
deeper submerged in fact than what is now the Great Valley." 
As a true conception of the age of the Coast ranges, as well 
as of the many oscillations of level recorded by their strata, 
is of the utmost importance for California geology it seems 
best to restate briefly what is at present known bearing on 
this subject. 
