&8 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4TH SER. 
At a later date a well was drilled by the Santa Fe Railroad 
Company in the western part of the Kern River field near the 
center of Sec. 24, VT. 285), R127 Ei attained a depth of 
only 2270 feet, and was then abandoned. The formations 
penetrated by this well were for the most part sandy beds 
with interstratified clays described in the log as “blue clays.” 
Only a little oil-sand was reported above 1260’, and less 
still below that depth. Many of the sandy beds carried water 
which required frequent shutting off in drilling the well. 
Most of the productive oil-wells in the Kern River field 
have penetrated only the upper member of the series, and but 
few have attained a depth of more than 1250 feet. The rec- 
ords show the beds to be mainly sand and sandy shale, which 
are separated by beds of clay distributed at intervals in the 
formation. Very little oil has been found below a depth of 
1250 feet, though the deep-well records report small quantities 
at a much greater depth. 
In 1909 the Santa Fe Railroad Company under the name of 
the Petroleum Development Company drilled a deep well, 
“Rasmussen No. 28,” on the S. E. % of Sec. 4, T. 29 S., R. 
28 E., and at the time of this writing had not ceased operations 
upon it. Through the kindness of Mr. F. C. Ripley, superin- 
tendent of the company, permission was obtained to make use 
of the following facts and records. 
In the upper part of the log the formations are chiefly clays 
and sands with the usual oil-sands of the district. Oil in 
paying quantities was not found below a depth of 905 feet 
from the surface. 
At a depth of 2694 feet the drill entered a hard sandstone 
from which was obtained a strong flow of salt water. At 
2805 feet a dark gray shale was reached which continued 
almost uninterruptedly for nearly 2000 feet. This formation 
of gray shale resembles very much the dark shales of the 
Eocene in the vicinity of the Tejon ranch, in the San Emidio 
hills. Fossils were brought up from a depth of near 2600 feet, 
including Turritella ocoyana, and Chione temblorensis. The 
sandy bed between 2694 and 2805 feet apparently marks the 
base of the Miocene. 
As will be seen, the thickness of the Neocene series is here 
also somewhat reduced by erosion—probably by as much as 450 
