California Tertiary Formations.—Hershey. 301 
West at an average angle of 45°. It is eroded into sharp hills 
several hundred feet high and the oldest Quaternary river 
terrace of Soledad canyon is trenched on its disturbed beds. 
Combining the three divisions, this great gravel deposit 
with its almost incredible thickness of about 8000 feet, appar- 
ently represents the Upper Pliocene alone. On structural and 
lithologic grounds I will correlate it in a general way with thé 
Paso Robles formation discriminated by Dr. H. W. Fairbanks.* 
in the Salinas valley and with the Merced series on San Fran- 
cisco peninsula, discriminated by Prof. A. C. Lawson,+ and 
proved by abundant fossils to represent the latest Pliocene 
time. Mr. Homer Hamlin, of Los Angeles, who is familiar 
with the geology of the southern Coast ranges, particularly 
of Monterey county, confirms this correlation. 
The three divisions are conformable to each other, but 
the lower rests on very diverse formations. On the northwest 
of the basin is Cretaceous shale; on the north, schist and 
gneiss; on the northeast, the Mellenia series; on the south- 
east, dioryte and granite; and on the southwest and west, a 
great series of light yellow coarse sandstones and conglom- 
erates which constitutes the San Fernando range and is heav- 
ily developed in the valley of the Santa Clara river between 
Camulos and the sea. This rests unconformably on the 
bituminous, oil-yielding shales of the Monterey formation 
and is conceded by all who have studied it, including Mr. 
Homer Hamlin and the present writer, to be the San Pablo 
formation, generally classed as Lower Pliocene. Mr. Hamlin 
says 5000 feet in thickness of it are clearly exposed in a single 
section on the southern face of the Sierra Madre range. 
Between San Fernando and Newhall, this supposed San 
Pablo has a prevailing dip to southwest at angles of 20° to 
40°, but a reverse dip sets in on the northern side of the 
mountain so that the non-conformity with the overlying 
gravel is not a conspicuous one although none the less real 
and significant. The older formation is well lithified and 
resists erosion well, giving rise to high, craggy mountains. 
The newer is merely an unconsolidated gravel and its terrane, 
abounds in many low hills and an intricate network of ravines. 
* Journal of Geology, Sept.-Oct., 1898, p. 565. 
* Bulletin of the Department of Geology, University of California, vol. i, 
No. 4, pp. 142-148. 
