Oncillaflons of the California Coast. — Fairbanks. 237 
vial bottoms above tlie points of tlooding were excavated out 
of the Pliocene or older strata, as the case may be, during an 
early Pleistocene elevation. 
The plains of Los Angeles stretch from Newport north to 
Santa Monica broken chiefly by the San Pedro hills. The 
plains are underlaid by a very considerable thickness of Pli{»- 
cene deposits, with Pleistocene on the surface. The submar- 
ine valleys at Newport, Redondo and Santa Monica must have 
been excavated chiefly in the Pliocene strata. The landward 
prolongation- of these valleys was of course obliterated in the 
recover^'- from the Pleistocene depression. The mouths of 
nearly all the streams in this section, as along the coast of 
San Diego county, are more or less flooded. It is possible that 
the recent depression of about 350 feet which Mr. W. S. T. 
Smith recognized on S-tnta Catalina island is the same as that 
shown by the small submarine valley at Newport, opposite 
the mouth of the Santa Ana river, which is not apparent at 
the depth of 100 fathoms but extends very close to the shore. 
The valley of the Santa Clara river has a general east and 
west direction curving toward the south near its mouth where 
the alluvial plain is many miles wide. The higher hills on 
either side are Miocene while the lower belong to the Pliocene. 
According to Mr. Watts* the valley is not a structural one 
but due to erosion. It is baseleveled for 30 miles from its 
mouth but the depth of the Pleistocene forming the bed on 
which it flows is not known. The submarine valley correspond- 
ing to this, as before remarked, comes very close to the shore. 
It miist be in great part cut out of the Pliocene filling of 
the post-Miocene erosion valley. There is no reasons what- 
ever for supposing that the deep and narrow valley could in 
any way be formed by the deformation of the Pliocene. 
No more large streams are met until western Santa Barbara 
count}'' is reached. Here the Santa Ynez and the Santa Maria 
enter the ocean with alluvial bottoms 10 and 5 miles wide re- 
spectively. No submarine valleys, are known opposite these 
rivers. It is possible that with the last uplift the channels were 
filled pari passu with the emergence of the land. Both of these 
streatns flow over sandy or gravelly beds for many miles back 
from their mouths. The Santa Ynez has a general course fol- 
* Verbal communication. 
