Vor. III] |= ANDERSON—FURTHER STRATIGRAPHIC STUDY 17 
In its structural features the Eocene is simple. It forms a 
monocline that dips away from the older rocks toward the 
Great valley with only such flexures in strike and dip as are 
consistent with the insular conditions of the period. The beds 
lie along the eastern and northern slopes of the range in such 
a manner as to be in general concentric with the Cretaceous, 
presenting in some places the appearance of conformity, but 
on the whole showing the strongest evidences of unconform- 
ity. This unconformity is evident, as the formations are fol- 
lowed along the range, not only in the physical character of 
the various beds and in their fauna, but also in the distribu- 
tion of the Eocene and the Cretaceous and in their lack of con- 
formity in detail in many places. 
On the western slope of the range, the structure of both the 
Eocene and the Cretaceous is less simple, and both formations 
are also less in evidence. The large amount of faulting which 
has taken place has complicated and obscured the geology, - 
and no clear statement can be made without much detailed 
work. 
THE MIOcENE SERIES 
Regarding the occurrence, stratigraphy, and distribution of 
the Miocene in the Mount Diablo range, a fairly good state- 
ment was given in the former paper, except as to a part of 
the territory north of Coalinga. Miocene rocks are co-exten- 
sive with the range and can be followed almost continuously 
throughout its entire length, particularly along its eastern 
flanks. 
In the earlier paper the stratigraphic divisions of the range 
were considered to be: 
(c) Coalinga beds 
(b) Monterey shales 
(a) Temblor beds 
These do not form an entirely conformable series, though in 
some places it is difficult, or even impossible, to draw the 
line sharply between the several members. The greatest degree 
