UNIVERSITY OF CALIFORNIA PUBLICATIONS 



BULLETIN OF THE DEPARTMENT OF 



GEOLOGY 



Vol. 8, No. 11, pp. 257-274a, pis. 26-28 Issued December 22, 1914 



THE MARTINEZ AND TEJON EOCENE AND 

 ASSOCIATED FORMATIONS OF THE 

 SANTA ANA MOUNTAINS 



BY 



ROY E. DICKERSON 



CONTENTS 



PAGK 



Introduction 257 



Historical 258 



Location and Physiographic Features 258 



Basement Complex 261 



Chico Group 262 



Martinez Group 263 



Tejon Group 265 



Lower Miocene 267 



Geologic History 269 



Summary 270 



INTRODUCTION 



The Santa Ana Mountains have been selected for this study 

 because the faunas and formations represented in this area furnish 

 important information concerning the relations between the various 

 Tertiary and Mesozoic formations of southern California and those of 

 northern California. The possibility of connecting the marine Tertiary 

 of southern California with the land-laid deposits of the Great Basin 

 region was also an incentive. The field work upon which this paper 

 is based was done by members of the University of California Summer 

 Session class in palaeontology. 1913, under the direction of the writer. 

 The writer is particularly indebted to Mr. Earl L. Packard, who sup- 

 plied most of the discussion on the Chico Cretaceous, and to Mr. John 

 P. Buwalda, who wrote portions of the text relating to the Miocene. 



