190 CALIFORNIA ACADEMY OF SCIENCES [Proc. 30 Ser. 



Conclusions. 



The conclusions to be arrived at from the stratigraphic 

 study of this field are not at variance with, but are mainly 

 confirmatory of much that has been written during the last 

 decade. The Tertiary^ formations of California have thus far 

 been too little studied and analyzed, though for general scien- 

 tific as well as for economic reasons they richly deserve 

 attention. In the present contribution to the literature it is 

 believed that the following points are either made clear or are 

 at least clearly indicated : 



1. Stratigraphic nonconformities exist in the Mount Dia- 

 blo Range between all of the chief periodic series, and in 

 some instances between different members of the same 

 series. 



2. The Eocene strata are capable of being divided into 

 several distinct members, of which the Tejon portion contains, 

 at least locally, two sandy members separated by one of 

 shale. 



3. The Neocene deposits of California can be separated 

 into two or more basins or minor provinces, those of the 

 Mount Diablo Range belonging to the California interior 

 basin and being characteristic of the same. 



4. In the Mount Diablo Range two clear stratigraphic 

 nonconformities exist within the Neocene, dividing these 

 deposits into three groups, lower, middle, and upper. The 

 lower and older of these groups contains the well recognized 

 Miocene strata of Central California ; the later and younger 

 group, the strata which have been described as Etchegoin or 

 San Pablo, and which are believed to be of Pliocene age: 

 while the interv^ening or middle group, on account of its 

 faunal resemblance to the older Miocene, is more logically 

 classed in this period than in the period following. 



5. In the older Miocene two distinct members are to be 

 recognized; viz., the Monterey Shale and the Temblor 

 Sandstone. 



6. The most complete and therefore the most typical 

 fauna of the Lower Miocene of the California interior is that 



