STUDIES IN THE NEOCENE OF CALIFORNIA. 439 
fication is distinct. In other places the strata are heavily bedded 
and frequently so intersected with joint planes that it is difficult 
to make out the real bedding. 
These two facies were not found occupying definite horizons, 
but, as in the Pescadero section, grade into each other irregu- 
larly in the vertical section. 
The third facies is more characteristic. It is hard, brown 
or dark colored conglomerate, heavy bedded, the pebbles of 
metamorphic rock are from one to four inches in diameter, and 
are sometimes distinctly faulted. 
The Pescadero section gave a questionable thickness of over 
10,000 feet. The exposure is cut off on the north by a noncon- 
formity, and on the south by a fault. The conglomerates at the 
top or south end of the section have a thickness of 720 feet. It 
is thought that the Carmelo series of Professor Lawson’ may be 
only a local development of the conglomeratic facies. 
Occurrence.—The Pescadero series is well exposed at Benicia ; 
in the northeastern quarter of San Francisco; in the San Bruno 
Mountains, and all through the Santa Cruz, Mount Hamilton and 
Monte Diablo Ranges. It will probably be found to be wide- 
spread throughout the Coast Ranges. 
Relations —No evidence of nonconformity between the Pesca- 
dero series and the metamorphic sandstone and phthanite was 
found, although one probably exists. The lowest Eocene and 
the uppermost Cretaceous are, as yet, unknown in California, and 
in the southern part of the state Chico beds lie unconformably 
on Knoxville, showing the absence of Horsetown strata. 
THE MONTEREY-MERCED PERIOD. 
The Monterey series was long ago described and assigned to 
the Miocene, and later investigations have not modified that 
decision. 
The Merced series was first mentioned by Whitney, who 
merely speaks of the finding of Pliocene strata on Seven Mile 
Beach* by Gabb and Remond. Until recently these beds seem 
* Univ. of Cal., Bull. Dept. Geol., Vol. I., p. 19. 
? Geol. Surv. of Cal., Geology, I., 79. 
