THE MARINE TERTIARY OF THE WEST COAST 603 
post-Monterey disturbance, and the strata were not upheaved to a great 
altitude. Faulting on a most magnificent scale took place along the earth- 
quake rift and certain other fault-zones, especially that in the Salinas Valley, 
and along these lines of displacement, masses of granitic rocks, which during 
the preceding epoch had been subject to little or no erosion, were suddenly 
thrust upward and left exposed to the ravages of streams that assumed the 
proportions of torrents in certain regions, as for instance adjacent to the 
Carrizo Plain in south-central California. The post-Monterey diastrophic 
movements in the Puget Sound province also produced sharp relief as is evi- 
denced by the coarse sediments immediately following the disturbance. The 
localization of movements during the period is exemplified at numerous locali- 
ties in the Coast Ranges. 
Throughout much of the coastal belt, and probably likewise in the interior, 
great volcanic activity took place during the middle Miocene, this being the 
last epoch of volcanism in the Coast Ranges, south of San Francisco Bay. 
It is interesting to note that only a comparatively short distance 
to the east of the southern Salinas Valley area, where the great 
unconformity between the Temblor and the Santa Margarita 
deposits is best seen, it has been very difficult to find the line 
separating these two horizons. Both the Santa Margarita and 
Temblor deposits to the southwest of the San Joaquin Valley 
are composed of organic shales, and in consequence of the diffi- 
culty in separating the two horizons the United States Geological 
Survey has applied the name Maricopa shale to the deposits 
as a whole.2, No marked stratigraphic break has been found in 
middle California between the deposits of the lower San Pablo 
series (Briones group) and those representing the Temblor. Here 
the beds of these two horizons are parallel, the chief basis for mak- 
ing the separation being irregular contacts and the difference 
between the faunas. In middle California, therefore, we have no 
evidence of crustal movements immediately after the deposition 
of the Temblor. 
Correlation.—Direct evidence for the correlation of the San 
Pablo series with the eastern and European sections is lacking. 
The writer has presented the evidence for the correlation of this 
tR. Arnold, ‘‘The Environment of the Tertiary Faunas of the Pacific Coast of 
the United States,” in Willis e¢ al., Outlines of Geology (1910), p. 241. 
2 R. W. Pack, ‘Geology and Oil Resources: Sunset-Midway Oil Field, California,” 
U.S. Geol. Surv., Prof. Paper 116 (1920), p. 35. 
