Vot. III] ANDERSON—FURTHER STRATIGRAPHIC STUDY 33 
Tejon ranch, Sunset, McKittrick, Coalinga, the Cantua creek, 
Tesla, and Mount Diablo. Their elevation varies between 
1200 and 1500 feet above the sea, or between 850 and 1000 
feet or more above the floor of the Great valley. On the west- 
ern side of the range their elevation is perhaps a little less, and 
there is also a greater variation throughout and a considerably 
greater extent, particularly about the head of the Salinas valley 
drainage. Along the foothills on either side of the range it is 
not unusual to see these terraces rising from 200 to 400 feet 
or more above the beds of the various stream valleys. These 
terraces are well exhibited in the lower hills in the vicinity of 
McKittrick, Midway, and the Kern river. Most of the oil 
wells of the McKittrick district are drilled upon the outer 
border of a large section of such a plain. Similar remnants 
and other evidences of base-leveling are plainly marked along 
the foothills about the southern end of the valley, especially in 
the neighborhood of the Tejon ranch, where a careful study 
would probably reveal a series of different levels. At the 
mouth of Grapevine canyon a terrace is cut at an elevation of 
600 feet above the floor of the valley. 
In the vicinity of Coalinga the terraces are well marked in 
many places both north and south, but especially in the foot- 
hills to the east of Alcalde and still further eastward in the 
Kettleman hills. Not only are these marginal remnants of 
the old base levels to be seen as terraces along the slopes of the 
higher range, but in many places in the outlying hills there 
are mesa-like ridges and flats strewn with the usual deposits 
of alluvial debris. 
The base-leveling here described has acted upon and trun- 
cated each and all of the stratigraphic series of the range, but 
naturally its effects have been most pronounced upon the 
younger and softer strata. In the foothills along the south- 
west border of the valley the denudation has beveled and 
truncated the upturned edges of all of the sedimentary series 
from the earliest to the latest, including the Etchegoin and 
even the Tulare beds. To a less extent it has acted upon the 
older series, but usually their greater hardness has protected 
them from the destructive effects of denudation. 
