THE MARINE TERTIARY OF THE WEST COAST 607 
PLIOCENE 
The marine Pliocene of the West Coast as now recognized is 
divisible into at least three distinct horizons: the Jacalitos, the 
Merced, and the Saugus. Continental deposits are found in 
different parts of the Coast ranges representing all three of these 
horizons, and in some instances to which reference has already 
been made these continental deposits are found closely associated 
with the marine beds. 
Stratigraphic relationship of the Pliocene and Upper Miocene.— — 
No evidence of folding between the beds of the Santa Margarita 
(Upper Miocene) and the Jacalitos (Lower Pliocene) has been 
obtained in southern California, though good erosion contacts are 
found separating them and the faunas are on the whole very differ- 
ent. In the vicinity of Mount Diablo, just to the east of the San 
Francisco region, the Santa Margarita beds were folded before the 
