172 The American Geologist. Novombor, isee 
tho formation of its axis as a whole, so recent as was formerly 
supposed. In the light of our present knowledge a return to 
the earlier opinion is very surprising. 
The«latements in Mr. Ransorae's paper to which the writer 
wishes to call especial attention and to which there are the 
most weighty objections are the following: 
"It is very doubtful whether anything at all comparable with the 
present valley existed during Cretaceous times At Paskenta on the 
west side of the Sacramento valley there is a great thickness of Creta- 
ceous strata exposed, dipping steeply toward the valley. Mr. Diller re- 
ferring to these strata, speaks of over 29,000 feet of sediments (Shasta- 
Chico series) being laid down in the Sacramento valley, but he probably 
hardly means to convey the impression that there was then any distinct 
valley. No such thickness of Cretaceous rocks is found on the eastern 
or Sierra Nevada side of the valley, and we should rather suppose that 
the sediments observed at Paskenta thin out under the present valley, 
and that their greatest thickness, and therefoj-e the deepest depression 
in which the Cretaceous sedimentary lense was being deposited, was 
either at the above named place or even at some place west of it, over 
the site of the jjresent Coast ranges. In the latter case the strata have 
probably been largely r(!moved by denudation. Throughout the Coast 
ranges the Cietaceous strata are so widely spread, and so considerable 
in volume, as to indicate that the region occupied by these mountains 
was not only submerged at that time, but was probably more deeply 
submerged than was the area of the present Great Valley. 
During the Eocene (Tejon), according to Mr. Diller. northern Califor- 
nia and a large part of Oregon were above sea and being degraded, no 
Eocene deposits being known in California above the 40th parallel. 
There was probably a gradual subsidence, as shown by the thinning 
out of the Tejon northward in California. But so much being granted, 
there is nothing to indicate that any step had been taken toward the 
initiation of the upper Sacramento Valley, while to the south of the 
40th parallel the probabilities are that the sea had an almost or wholly 
xanbroken sweep across the area now occupied by the Coast langes and 
the Great Valley .... It is possible that with further knowledge of tht; 
mountain ranges inclosing the Great Valley we may be able to trace in 
Miocene times the first faint boundaries of the whole or part of the 
valley as known to us to-day, but at the present time we must agree 
substantially with Antisell in considering that 'probably during the 
whole of the Miocene the Coast range was altogether Iteneath the sea- 
level,' and take up its history at a point subsequent to that time. 
The occurrence of a great orogenic disturbance at the close of the 
Miocene, giving birth to the Coast ranges as a connected mountain 
chain, appears to l)e one of the best established facts in the geology of 
California. From that disturbance dates the history of the Great Val 
Jey According to the U. S. Geological Survey the Great Valley was 
probably occupied during the whole of the Neocene by a gulf, connect- 
