California Tertiary Formations.—Hershey. 359 
Tue Upper PLIOCENE SERIES. 
The Upper Pliocene basin of the Santa Clara river val- 
ley is oval in shape, with its major axis east to west. It ex- 
tends from a point in Soledad canyon one-half mile east of 
Lang station to near the Camulos ranch, a distance of about 
20 miles and from a point one mile south of Newhall to four 
miles up Castaic creek, a distance of about 10 miles. On all 
sides the strata dip toward the center of the basin at angles of 
20 to 30, but the chief disturbance is an unsymmetrical an- 
ticline traversing the area from northwest to southeast on the 
line of Castaic creek and Saugus. On one side of the strata, 
even the very latest Pliocene, dip to southwest at an average 
angle of 45’, not infrequently increasing to 60 or 70’, while the 
northeast slope is longer and gentler. 
The strata within the basin are clearly divisible into 
three members which, in field notes, I have designated the 
Buff, the White and the Red Banded, but it may be conven- 
ient to name them the Lang, the Soledad and Saugus divis- 
ions. 
The Lang Division.—This is a great bed of gravel and 
sand of a uniform buff color which is a distinguishing mark 
all around the basin. Red and brown lava cobbles are plen- 
tiful but there is also much granitic debris. The major 
bedding planes are regular but within each stratum there is 
the irregular and somewhat indistinct stratification common 
to alluvial deposits. It has the appearance of the delta of 
some large river flowing westward on the site approximately 
of Soledad canyon, perhaps draining Antelope valley, in part 
at least. Coarse gravel and boulders up to three feet in diam- 
eter occur at various levels in the deposit and even to the cen- 
ter of the basin: It is too well waterworn and too well strat- 
ied to be one of the “detrital slope’? accumulations so com- 
mon in the arid region. The width of the outcrop of this di- 
vision of the Upper Pliocene near Lang station is about two 
miles, and a conservative estimate of its thickness (based on 
good data, with all faulting eliminated,) gives it 3000 feet. 
The Soledad Division—This is gravel and sand, chiefly 
granitic, with lava pebbles and cobbles less abundant. It 
is finer in texture, more regularly bedded, and slightly more 
lithified than the lower members. It is inclined to outcrop in 
