OTHER OCCURRENCES 298 



of the Tejoii, locally known as the Domengine sands. He suggested that 

 the Turritella andersoni beds might be Martinez in age. E. T. Dumble^'^ 

 was so impressed with the importance of this contact that he unhesitat- 

 ingly expressed the belief that the Turritella andersoni beds were Martinez 

 in age. In his paper entitled "Notes on Tertiary deposits near Coalinga 

 oil field and their stratigraphic relations with the Upper Cretaceous'' 

 occurs the following statement: 



"Our work now proves that this lower member of the Eocene (the Martinez) 

 is of very considerable extent southward on the west side of San Joaquin 

 Valley ; that it consists of three or more clearly defined members, and that, in 

 addition to the unconformity already described between it and the Cretaceous, 

 there also exists a decided unconformity between it and the overlying Tejon." 



Robert Anderson and Robert W. Pack,^^ in their paper entitled "Geol- 

 ogy and oil resources of the west border of the San Joaquin Valley north 

 of Coalinga^ California," referred the Turritella andersoni beds to the 

 Martinez ? Their point of view is stated as follows : 



"The relation of the Martinez? formation to the overlying Tejon formation 

 may be stated with more assurance" to be one of unconformity. . . . The 

 writers believe that the beds here described as Martinez? are probably the 

 equivalent partly of the Martinez and partly of the Tejon, and that the uncon- 

 formity here registered in the Eocene is not to be correlated with that between 

 the Martinez and Tejon formations in the Mount Diablo region." 



Thus in the foregoing we have the suggestion that possibly the Turri- 

 tella andersoni beds are transitional between true Tejon and true Mar- 

 tinez. 



Dickerson/^ in his paper entitled "Stratigraphy and fauna of the 

 Tejon Eocene of California/' states his belief that the unconformity be- 

 tween the Turritella andersoni beds and the beds regarded as the base of 

 the Tejon by the writers just quoted is not important. He says : 



"Several workers in this field report a well marked unconformity in the 

 middle of the section. The time represented by this unconformity is difficult 

 to evaluate. The only method at present available is the faunal one, and, as 

 has been previously shown, the faunas from above and below the unconformity 

 are as a whole quite similar. There is no well marked difference in dip and 

 strike reported along the unconformable contact ; but the evidence consists of 

 a sharp change in lithology and the penetration of the underlying strata by 



10 E. T. Dumble : Jour, of Geology, vol. 20, 1912, pp. 28-37. 



^ Robert Anderson and Robert W. Pack : U. S. Geol. Survey, Bull. no. 603, 1915, p. 66. 



12 More assurance than the unconformity between the Chico and the Martinez, just 

 described in the paragraph preceding this. 



13 R. E. Dickerson : Univ. of California Publ. Bull. Dept. Geol., vol. 9, no. 17, 1916, pp. 

 428-429. 



