400 



H. W. TURNER — GEOLOGY OF MOUNT DIABLO. 



and these are followed successively by Miocene, Pliocene, and post-Pliocene 

 deposits. 



The accompanying sections illustrate the general structure of the district. 



The section figure 1, extending from Clayton to Oyster point, exhibits 

 best the influence of the central metamorphic mass on the outlying later ter- 



FiGURE 1.— Section through Mount Diablo. 



ranes. The limit between the Chico and the Knoxville series is only claimed 

 to be approximately located, and the strata to the south of the mountain 

 between the metamorphic area and Curry creek are called Chico only 

 because of this similarity to and conformity with the known Chico strata 

 south of Curry creek. No fossils were obtained on the southern slope of 

 the mountain north of Curry creek. The beds here are possibly of the 

 Wallala epoch. 



MetamorpUc 



1^'iGURE 2.— Section from North Peak to Kirker Pass. 



The section extending from North peak to Kirker pass shows an appar- 

 ently conformable series from the Knoxville to the Pliocene ; but, as before 

 stated, there is no doubt that a considerable time elapsed between the close 

 of the Knoxville epoch and the opening of the Chico epoch. It is also pos- 

 sible that some of the lower beds represented in this section as upper Creta- 

 ceous are really of the Wallala epoch. The beds represented as Miocene 



Figure Z.— Section from Tasajero Creek to Lone Tree Valley. 



in the section are so considered on lithological and stratigraphical grounds, 

 no fossils having been found in them at this particular point. 



The section from Tasajero creek to Lone Tree valley shows the reversed 

 strata east of Tasajero creek, where the Eocene and upper Cretaceous overlie 



