600 BRUCE L. CLARK 
indicate a moderate temperature. Dr. J. C. Branner, in a paper 
read before the Cordilleran Section of the Geological Society of 
America, suggested an explanation of this apparent disagreement 
between the floral and faunal evidence.t The great thickness of 
diatomaceous shales in southern California is to be explained by 
the hypothesis that cold currents carried the diatoms southward 
along the coast and finally into the partially land-locked basins 
of southern California where they were killed by the change in 
temperature. The continuous supply from the north resulted in 
great thicknesses of deposits composed largely of the tests of these 
minute plants. This hypothesis may also be an explanation of 
the origin of the diatomaceous shales of the Oligocene and Upper 
Miocene. | 
Paleogeography—The Temblor deposits have much wider dis- 
tribution than those of the Vaqueros (Figs. 6 and 7) and are found 
on the eastern as well as the western side of the Coast ranges. On 
the eastern side from the vicinity of Coalinga northward these 
deposits are composed of coarse clastics, while to the west organic 
shales cover the larger part of the section. The comparison of the 
area covered by this sea with that which existed during Lower 
Oligocene time (when the Kreyenhagen shales were deposited), 
(Fig. 4) shows a marked change. As has already been stated, the 
Oligocene sediments were deposited in an inland north-south trough 
very similar to that which existed during the Eocene. The deepest 
part of the Oligocene trough was on the eastern side of the present 
Coast ranges, a very large part of the western side at that time 
apparently having been subject to erosion. On the other hand, 
the deepest part of the Temblor sea was on the western side of the 
present Coast ranges; the areas which had been land during the 
Oligocene were inundated, while to the east, where the Oligocene 
trough had been deepest, the strand-line deposits indicate shallow 
water conditions. At this time the interior Diablo range prob- 
ably formed an archipelago of islands. 
San Pablo series—The San Pablo series is recognized as the 
second major division of the Miocene. Like the San Lorenzo and 
J.C. Branner, “Influence of Wind on the Accumulation of Oil-bearing Rocks,” 
Proc. Thirteenth Ann. Meeting of the Cordilleran Section of the Geol. Soc. of Am., Bull. 
Geol. Soc. Am., Vol. XXIV (1913), pp. 94-95. 
