BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA 



Vol. 29, pp. 281-296 JUNE 30, 191S 



PROCEEDINGS OF THE PALEONTOLOGICAL SOCIETY 



MEGANOS GEOUP, A NEWLY RECOGNIZED DIVISION IN 

 THE EOCENE OF CALIFORNIA * 



{Read before the Paleontological Society January 2, 1918) 



BY BRUCE L. CLARK 



CONTENTS 



Page 



[ntroductory statement 281 



Previous literature concerning the Eocene of the Mount Diablo quadrangle 282 



Meganos group north of Mount Diablo 283 



Stratigraphy and lithology 283 



The area under consideration 283 



Summary of lithology of section 285 



Evidence for unconformity between Meganos and Tejon 288 



Faunal list 289 



Comparison of Meganos and Tejon faunas 289 



Meganos group to south and west of Mount Diablo 290 



General statement 290 



Stratigraphy and lithology 291 



Fauna 292 



Other occurrences of Meganos 292 



General reference 292 



Coalinga district 292 



Eocene of Calabasis quadrangle, Ventura County 294 



Summary of conclusions 295 



Introductory Statement 



During the summer of 1917, while studying the Tertiary formations 

 on the north side of Mount Diablo, in the Mount Diablo quadrangle, the 

 writer noticed a marked difference in strike between certain of the beds 

 which up to this time had been considered a part of the Tejou (Upper 

 Eocene). This discordance, a difference of nearly 50 degrees, meant one 

 of two things : either it was due to faulting or to an unconformity. T^ater 



* Manuscript received by the Secretary of the Geological Society March 5, 1918. 

 XXII — Bull. Geol. Soc. Am., Vol. 29, 1917 (281) 



