Vol. V] DICKERSON— FAUNA OF THE TYPE TEJON 39 



TEJON GROUP AT TYPE LOCALITY. 



STRATIGRAPHY. 



The Tejon group at the type locality is a portion of an east- 

 west strip which extends from Tunis Creek on the north flanks 

 of the Tehachapi Mountains to a point about three miles south- 

 east of Pattiway where it is cut off by the San Andreas Fault. 

 The map (see Text Figure 1) which is adapted from the 

 ''Preliminary Report on the Geology and Possible Oil Re- 

 sources of the South End of the San Joaquin Valley, Cal." by 

 Robert Anderson shows the general distribution of the Tejon 

 very satisfactorily. 



The Tejon strata in the vicinity of Grapevine Creek rest 

 upon a Basement Complex consisting of granitic rocks and 

 associated schists. The beds in general have a steep north dip 

 of 75° to 85°, but are disturbed in places so that the dip is re- 

 versed. The basal member, about 250 to 300 feet in thickness, 

 consists of a very coarse conglomerate derived from the gran- 

 itic rocks of the Basement Complex. This member is overlain 

 by about 1000 to 1200 feet of thin bedded, brown sandstone 

 with subordinate strata of dark gray, clay shale containing 

 limestone nodules. The sandstone is, in places, conglomeritic 

 and in one locality the dark gray pebbles of shale yielded a 

 small Pec ten. The occurrence of this Pecten suggests the 

 deposition of earlier deposits which were completely removed 

 during Eocene time. The uppermost strata — about 1200 feet 

 in thickness — consist chiefly of light tan sandstone with sub- 

 ordinate strata of shale and brown sandstone. The total thick- 

 ness of the Tejon group along Grapevine Creek (Canada de 

 las Uvas) is about 2500 feet. The Tejon is overlain by vol- 

 canic ash of Oligocene or Miocene age on the west side of 

 Grapevine Creek. Mr. Bruce Martin states that the upper- 

 most Tejon beds in Live Oak Creek are covered by a lava 

 flow. 



FAUNA 



The middle portion of Tejon group in the vicinity of Grape- 

 vine Creek is particularly rich in upper Eocene species. The 

 basal beds yielded a small fauna (Cal. Acad. Sci. locality 246) 

 which consists of Spondylus carlosensis, Barhatia, sp., Mcre- 

 trix, sp. and Ostrea, sp. 



