110 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4TH Ser. 
Temblor sandstones and shales which are quite comparable 
to those of the Kern River. It may be added also that in 
the outer coast ranges the thickness of the Monterey is often 
as great as 3000 or 4000 feet, though this thickness may not 
be constant. 
On the other hand, as shown in previous papers, and as 
admitted by others, at Coalinga and vicinity the Monterey is 
but very little developed, and in the Mt. Diablo Range north 
of Jacalitos Creek it is not clearly recognizable at all, and if 
actually present it is in very greatly reduced volume. Nor 
has it been recognized at any place on the eastern border of 
the Temblor basin. 
It may be said, then, with reference to the Temblor, and 
also to the Monterey, that the conditions during the early 
and middle Miocene were similar in the Kern River area and 
in the Mt. Diablo Range in the vicinity of Coalinga. In both 
places on the borders of the Temblor basin the Temblor 
deposits are fairly well developed, while the Monterey is either 
absent, or is present in a reduced or disguised form. There 
are other facts that emphasize the absence of the Monterey on 
the eastern and northern borders of the basin, as will be shown 
later. 
The explanation of this interesting fact is to be found no 
doubt in the diastrophic record of the times. The subsidence 
that inaugurated the occupation of this basin by Temblor sedi- 
ments continued without interruption until middle Miocene 
time. It then paused, and on the eastern and northern borders 
of the basin the shore lines remained stationary throughout 
the epoch of the Monterey. In these parts, therefore, sedi- 
mentation was nil, while along the western borders, in the 
position of the outer coast ranges, and about the southern 
portion of the Mt. Diablo Range, subsidence went on without 
cessation, and sedimentation was therefore continuous. 
It is unnecessary to suppose that there was any elevation 
and denudation of the older Miocene during the Monterey 
epoch, either in the Kern River area or elsewhere, and no 
such disturbance seems probable. The facts appear to indicate 
merely an epoch of stability along the eastern and northern 
shore-lines of the basin, along which, therefore, the conditions 
