Vol. VII] GESTER— GEOLOGY McKlTTRlCK DISTRICT 223 



The specimens of the above quoted species are numerous and 

 very perfect. Similar forms and fragments of Anodonta were 

 noted by Mr. F. M. Ander.son in a number of the Universal 

 Oil Co.'s wells and by Dr. E. A. Starke in the wells of the 

 Standard Oil Co. Invariably they come from fine sand or 

 sandy shale a comparatively short distance above the oil 

 sands. In the southern and eastern portions of the field the 

 Tulare beds are much thicker than at the north. 



In and just above the oil and gas sands in many wells, in 

 the Lost Hills, various species of marine Lower Etchegoin 

 (Lower Pliocene) fossils have been found. Fragments of 

 marine shells are reported in nearly all of the drilling records 

 and some nearly perfect specimens have been either blown out 

 by gas or bailed out of the wells. 



From one of the Universal Oil Co. wells. Sec. 32, the fol- 

 lowing forms were noted at a depth of about 790 feet. 



Pecten crassicardo. Nassa californica. 



Echinarachnius gibbsi. Trophon ponderosum (?). 



Mulinia densata (Pseudocardium Macoma vanvlecki. 



gabbi). Cardium, species. 



Macoma inquinata. Chione, species. 

 Pecten oweni. 



Similar fonns including fragments of either Pecten estrell- 

 .(inus, or Pecten eldridgei, and Nassa calif ornka were reported 

 as coming from the oil horizon of the Standard Oil Co.'s 

 wells, Sec. 4. 



No specimens from, or records of. determinable species 

 from the lower oil sands in the Lost Hills are at hand, but 

 this light gravity oil comes from sands in the lower part of 

 the Etchegoin and from a sandy shale in the upper part of the 

 Santa Margarita. There are two, and possibly three, oil 

 sands recognized in the records of the Lost Hills wells, all 

 within the limits of the Lower Etchegoin and other sands as 

 shown in the accompanying diagram, which is typical of the 

 general conditions that obtain in the Lost Hills. 



Belridge 

 Similar conditions obtain at Belridge as at Lost Hills, but 

 incomplete records, due to a seemingly unnecessary caution on 

 the part of some of the operators in not giving out records, 

 have rendered a study of this field less complete. 



