90 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4TH SER. 
followed toward the northwest, the beds pass into the normal 
marine conditions of the lower Miocene already described. 
Overlying this brackish-water series above described are the 
beds of the Kern River group forming a wide overlap. 
DIVISIONS OF THE NEOCENE 
In the foregoing descriptions it has been shown that, upon 
the basis of lithology, the Neocene series can be divided more 
or less satisfactorily into three groups, two of which are 
thick, sandy aggregates separated by a third, in which clays 
and organic shales form a prominent part, constituting prob- 
ably half its volume. If, on the other hand, the division is 
based upon other criteria it is not easy to separate the two 
lower members, though the upper one remains distinct. 
On the whole the most natural division accords with the 
data of paleontology, and as measured in the outcrops is 
roughly as follows: 
Gravels and sands, 250’ 
Kern River sands and clays, without fossils, t 1260’ 
Group. but including the Kern oil-meas- 
ures. 
Neocene j Unconformity 
Lower Miocene; clays, ashy beds, 
shales, white and yellow sands 1160’ 
with marine fossils; 
Sands, sandy ash-beds, pumiceous 
ash-beds, and conglomerate, with 600’ 
(marine fossils. 
Total Thickness, 3270' 
Temblor 
es and brown beds, gravels, ) 
’ Group. 
THe TEMBLOR GROUP 
Basal Member.—The basal division of the Neocene series, 
like the upper division, is essentially sandy; but, unlike the 
latter, the rocks are often considerably indurated, and some- 
times concretionary. Fossil invertebrates are often abundant, 
and have doubtless contributed cementing material to the con- 
cretions and to other hard portions of the strata. Some of 
the lower beds consist largely of volcanic ash, pumice, and 
sand, as has been already noticed by previous writers, and 
in this paper. Basal conglomerates are visible in only a few 
places, but a stratum of at least 50 feet is exposed at one 
