1914] Dickerson: Fauna of the Martinez Eocene of California 69 



AEEAL DISTRIBUTION OF THE MARTINEZ IN CALIFORNIA 



PRINCIPAL LOCALITIES 



The most northerly occurrence of Martinez thus far reported is 

 near the town of Lower Lake, in Lake County. Martinez strata occur 

 in the Napa Quadrangle four miles northwest of Suisun, where Gabb 12 

 found fine specimens of Turrit ella pachecoensis and Meretrix(f) 

 fragilis, and near Benicia. Across the Carquinez Strait from Benicia 

 is the type locality of the Martinez near the town of that name. In 

 1909, R. W. Pack and G. E. Gester recognized a small area of Martinez 

 on Carquinez Strait at Selby Station. North of Mount Diablo another 

 area occurs, and a very small but interesting locality was found south- 

 west of Mount Diablo by the 1911 University of California Summer 

 Session class in palaeontology. Beds of Martinez age make up a 

 portion of the strata at San Pedro Point, in San Mateo County. 

 Dumble 13 reported Martinez north of Coalinga, but later work has 

 shown that these beds are a phase of the Tejon. 



A typical collection of Martinez fossils was made by the 1910 

 Stanford University class in geology forty miles northwest of Los 

 Angeles in the Calabassas Quadrangle. Arnold 14 reported Martinez at 

 Rock Creek, Los Angeles County. The Martinez was recognized by 

 the 1913 University of California Summer Session class in palaeon- 

 tology in the Santa Ana Mountains. No positive evidence of Martinez 

 south of this last point is known, but Stanton 15 reports Glycimeris 

 veatchii var. major from Point Loma near San Diego. None of the 

 collections from this locality which the writer has examined have con- 

 tained any typical Martinez forms; all appear to be Tejon or Chico. 



DISTRIBUTION OF THE MARTINEZ COMPARED WITH THAT OF THE TEJON 



Some interesting relations between the Martinez and the Tejon are 

 brought out when their distribution is studied. (See fig. 1.) In 

 certain localities the Martinez and Tejon occur together, but in other 



i^ Gabb., W. M., Kept. Geol. Surv. of California, Palaeontology, vol. 2, p. 135, 

 1869. 



is Dumble, E. T., Notes on Tertiary Deposits near Coalinga Oil Field and 

 their Stratigraphic Eelations with Upper Cretaceous, Jour. Geol., vol. 20, pp. 

 28-37, 1912. 



i* Arnold, E., Tertiary and Quaternary Pectens of California, Professional 

 Paper no. 47, U. S. Geological Survey, p. 11, 1906. 



is Stanton, T. W., The Faunal Eelations of the Eocene and Upper Cretaceous 

 on the Pacific Coast, 17th Ann. Eept. U. S. Geol. Surv., p. 1040, 1895-6. 



