22 University of California Publications in Geology I Vol. 8 



as at the above described locality, but several species other than the 

 ones mentioned have been found in these gray-green shales above zone 

 1 south of Mount Diablo. 



ZONE 2 



Resting upon these shales 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 weather- 

 ing habit, a tendency to form prominent walls and caves. 



A fossiliferous horizon at the top of the first bluff yielded the 

 following species : 



Turbinolia, n.sp. (short form). 

 Astarte mathewsonii Gabb. 

 Cardium cooperi Gabb. 

 Cardium breweri Gabb. 

 Gari(?) texta Gabb. 

 Leda gabbi Conrad. 

 Meretrix hornii Gabb. 

 Meretrix uvasana Gabb. 

 Ostrea, sp. 



Solen parallelus Gabb. 

 Tapes eonradiana Gabb. 

 Tellina hornii Gabb. 



Bulla hornii Gabb. 

 Cyliehna costata Gabb. 

 Ficopsis remondii Gabb. 

 Fusus diaboli Gabb. 

 Galerus excentricus Gabb. 

 Megistostoma striata Gabb. 

 Cassidaria tubereulata (Gabb). 

 Spiroglyphus (f ) tejonensis Arnold. 

 Tritonium californicum Gabb. 

 Turritella uvasana Conrad. 

 Xenophora (?) sp. 

 Dentalium, sp. 



This fauna is characterized by Turritella uvasana Conrad. 



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 stringers 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. In 

 this middle zone Turritella, n.sp., was in the upper portion of these 

 beds. This species is also common in the group northwest of Coalinga 

 which has been referred to the Martinez, but its occurrence here, taken 

 together with other evidence, proves that this reference is incorrect. 



The second bluff sandstone of one to two hundred feet overlies 

 the thin-bedded sandstones and carbonaceous shales. It is for the 

 most part non-fossiliferous. In sandstone about one hundred feet 

 above it a fauna which was similar to that of the first bluff sandstone 

 was obtained. The similarity in fauna of these two horizons indicate 

 that the oscillations represented by the seven hundred feet of alter- 

 nating shales and sandstones were of short duration. 



