374 



University of California Publications in Geology [Vol. 9 



they are the most characteristic forms of the Rimella simplex zone 

 of the Tejon group. 



Above the basal portion is about twenty-five to fifty feet of a 

 deep-water facies of this zone consisting of fine-grained, gray, fora- 

 miniferal shales, which yielded Pecten inter radiatus Gabb, Schizaster 

 lecontei Merriam, Venericardia planicosta Lamarck, and several spe- 

 cies of foraminifers. These beds, which were evidently deposited in 

 moderately deep water as the presence of glauconite and abundance 

 of Schizaster lecontei and foraminifers show, are far better devel- 

 oped in the south limb of Pacheco Syncline, where they have yielded 

 the fauna listed under localities 215, 337, 532. This facies is not 

 quite so well developed south of Mount Diablo as in the Pacheco 

 Syncline. 



The stratigraphic position of the beds yielding the Turbinolia 

 fauna, the presence of several species which are generally charac- 

 teristic of the Martinez, the presence of several species which appear 

 to be restricted to the Turbinolia zone, and the absence of several 

 characteristic forms common in the Rimella simplex zone indicate a 

 life condition which is decidedly closer to the Martinez, the lower 

 Eocene, than that of the Tejon of Canada de las Uvas. However, 

 the presence of seventy-five or eighty species typical of the Tejon 

 of the type locality connects this fauna with that of the Rimella 

 simplex zone and shows that both are zonal phases of the upper 

 Eocene, the Tejon group. 



Rimella Simplex Zoxe 



Resting upon the gray-green shales of the Turbinolia zone are 

 from one hundred to two hundred feet of massive tan sandstones 

 constituting the first '"bluff sandstone"'. As the name implies, these 

 strata have a very characteristic weathering habit, a tendency to 

 form prominent walls and caves. 



Above the first bluff is seven hundred feet of strata made up of 

 alternating thin-bedded sandstones and carbonaceous shales which at 

 places contain thin seams of lignite. This apparently represents 

 several local oscillations of the coast in Tejon time, thus giving rise 

 to marine littoral, brackish, or even fresh-water conditions. Its 

 fauna is the same as the one obtained above the first bluff sandstone. 

 Turritella andersoni, n. sp. was found in the upper portion of these 

 beds. This species is also common in the Eocene beds northwest of 

 Coalinga which have been referred to the Martinez, but its occur- 



