228 University of California Publications in Geology [Vol. 7 



posits whatever part or portion of the whole Monterey time they 

 represented. The arguments for marked change in climate do 

 not appear to apply particularly, for unless the volume of silt- 

 laden water discharged from the land had been comparatively 

 small there could not have been such pure diatomaceous materials 

 deposited at any portion of the period so close to shore as we 

 know them to have been throughout the whole province, and 

 this applies to the lower as well as the upper portions of the 

 series. The evidence favors an arid climate throughout. 



South End San Joaquin Valley, R. Anderson, 1912. — In the 

 spring of the present year (1912) Robert Anderson published 77 

 a "Preliminary Report on the Geology and Possible Oil Re- 

 sources of the South End of the San Joaquin Valley" — the 

 region lying along the mountain flanks between the McKittrick- 

 Sunset area and the Kern River region just discussed. He says 

 "Although great differences in thickness and details of litho- 

 logic character occur, the similarity is sufficient to show that the 

 major features of the Tertiary geologic history were alike on 

 the two sides of the valley. ..." "In the Temblor Range field 

 the lower division corresponds to the Vaqueros sandstone (lower 

 Miocene), the middle one to the Monterey shale, and the similar 

 shale of the Santa Margarita (?) formation (middle Miocene)" 

 (p. 115). 



A most interesting relationship is brought out in the statement 

 that "At the south end of the valley the formations of the 

 Temblor Range continue into the San Emigdio region, with 

 changes, however, that alter the section considerably, especially 

 in the lower and middle divisions. ... A significant change is 

 the decrease in the exposed thickness of the organic shale from 

 several thousand feet in the Temblor Range to about 1000 feet 

 in the San Emigdio region, and its gradation into a less diato- 

 maceous and more clayey and sandy type of shale. Whether 

 this is due to the fact that a smaller volume of the organic 

 sediment was deposited here, or to its having been partly eroded 

 in this region, owing to its nearness to the zone of uplift repre- 

 sented by the granite mountains, or to its being hidden in part 



" U. S. Geol. Surv. Bull., 471-A, pp. 102-132 (April, 1912). 



