OTHER OCCURRENCES 295 



new species of Turritella in his so-called Martinez, Turritella reversa, is 

 found very abundantly in the Meganos beds of the Mount Diablo region. 



'Note. — During the summer of 1918 a number of the most important 

 Eocene sections in southern California were studied by the writer; these 

 included the Coalinga section and that of the Calabasis quadrangle, both 

 mentioned above. The details of this work will be published in the near 

 future. Briefly stated, the results are as follows: 



In the Coalinga section a marked unconformity was found separating 

 the Turritella andersoni beds (now known to belong to the Meganos epoch 

 of deposition) from those of the t3^pical Tejon. l^ot only is the contact 

 irregular between the beds of these two groups, but also there is a notice- 

 able difference in dip and strike at many localities, together with a true 

 basal conglomerate at the base of the Tejon. In this general region the 

 Martinez is absent; the Meganos group rests on the Upper Cretaceous 

 shales. 



In the Calabasis quadrangle, the section studied by C. A. Waring, 

 whose paper was referred to above, the Martinez, the Meganos (Turritella 

 andersoni beds), and the Tejon are all present. The Tejon of this section 

 rests unconformably on the Meganos, the unconformity being indicated 

 by an irregular contact, a marked difference in strike, and a possible dif- 

 ference in dip, together with a basal conglomerate. A very good typical 

 Tejon fauna was obtained above this contact. 



The writer's conclusion is that the Meganos group is to be correlated, 

 at least in part, with the marine phase of the lone as found at Table 

 Mountain, near Oroville, California, the fauna from which latter beds 

 has been referred by Dickerson^^ to his Siphonalis sutterensis zone. The 

 writer has refrained from using the name lone for the beds belonging to 

 this epoch of deposition as found in different parts of California, for it is 

 believed that the lone very probably is composed of beds belonging to 

 more than one epoch of deposition. 



Summary of Cokclusion-s 



1. Mapping of the sedimentary series of the Eocene in the Mount 

 Diablo quadrangle shows that there are three distinct stratigraphic units 

 in these deposits instead of two, as was formerly recognized. 



2. The beds of this newly discovered epoch of deposition come between 

 the Martinez (Lower Eocene) and the Tejon (Upper Eocene). 



3. The name Meganos lias been given to this group of deposits. 



IS R. E. Dickerson : Note on the faunal zones of the Tejon sroup. Univ. of ralifornia 

 Pnbl,. Bull. Dept. Geol., vol. 18, no. 2, 1914, p. 23. 



