82 CALIFORNIA ACADEMY OF SCIENCES [Proc. 47H Ser. 
localities, and the flattest is along the western border of the 
hills. There are a few local undulations that develop low 
anticlinal arches elongated in a northwest and southeast direc- 
tion. One of these anticlines traverses the developed oil dis- 
trict of the Kern River, and, according to Eldridge, another 
is found farther north. Another is to be seen along the 
eastern border of the area just north of the Kern River, and 
may be followed to the northwest across Poso Creek. It lies 
a little to the west of the fuller’s-earth mine on the road from 
Poso station to Granite. There is a corresponding syncline 
to the east of this, midway between the Granite road and 
Adobe canyon. 
The evidences of faulting within the Neocene area are 
almost negligible, though such faulting has taken place. 
Faulting to a greater extent has taken place along the eastern 
margin of the area, following in a general way, and in part, the 
contact with the basement rocks, and extending also at right 
angles to it for a limited distance at one point at least. 
The faulting along the margin has evidently been of the 
normal type, and was probably progressive, resulting in a 
displacement of at least a few hundred feet in some places, 
and much more in others. At Pyramid Hill, the lowest Neo- 
cene beds known within the area are left exposed at a consid- 
erable elevation, resting upon a floor of granite. Near Walker 
Basin Creek, beds of sandy ash, which are apparently of Lower 
Miocene age, are severed from the main area and left stranded 
at an elevation of 2500 to 3000 feet upon the granites, indicat- 
ing a throw of 1000 feet or more. 
The structure of the Neocene beds developed by this faulting 
is partially expressed in the Poso anticline previously men- 
tioned. It seems probable that the faulting has been pro- 
gressive, and pari passu with the corrasion of such narrow 
defiles as that of the Kern River; but this aspect of the subject 
cannot be fully taken up at present. 
North of Poso Creek, erosion has greatly excavated the 
Neocene sediments along the line of contact, forming small 
deep valleys in which the strata are clearly exposed. 
In the head of Adobe canyon and near Granite station, where 
the structure of the Neocene beds resting upon or against the 
basement rocks is well shown, they are seen to be almost 
