244 The American Geologist. October, i897 
The difllculty of always being able to discriminate between 
the effects of the different movements is not overlooked, or 
the possibility of their being more complex than at present 
believed. It will be [)erceived that this view introduces an- 
other complete vibration, making two where professor Lawson 
has one, and appears in a general way to harmonize the move- 
ments on the Pacific coast with those recognized by many 
students in other portions of North America. 
The marked orogenic disturbances which accompanied the 
epeirogenic movements at the close of what has been termed 
the Miocene, as well as those which have been considered as 
limiting the Pliocene in the Coast Ranges, should continue to 
be used as in the past to set off the rocks of tliese ])eri(jds. 
These disturbances were accompanied by lava flows and re- 
sulted in marked nonconformities. The intensity of the oro- 
graphic movements varied along the 800 miles of the Califor- 
nia coast, and in the interior, so that owing to different con- 
ditions of life, as well as to this intensity, the number of 
extinct forms in the different beds, particularly in the Plio- 
cene, show a considerable variation. The total outcome of 
the movements because of their local intensification has re- 
sulted in the elevation of Miocene strata over 6000 feet in 
portions of the Coast Ranges, while to the south near San 
Diego strata of that age are apparently absent. 
It is believed that the various lines of evidence presented 
in regard to a supposed post-Pliocene uplift are incontrovert- 
ible, and that the disturbances recognized by all as occurring 
at that time could not have left the general level of the coast 
less than 1000 feet and probably much more than that, above 
the present, and that the upturned Pliocene beds were truncated 
by subaerial erosion previous to the terracing. This elevation 
must have been sufficient and perhaps much more than suffi- 
cient to permit of a connection of the Santa Barbara islands 
with the mainland. The movements of the islands also seem 
to have corresponded very closely with those of the mainland. 
It is believed that tlie submarine valleys are in most cases 
if not in all explainable by no other hypothesis than that of 
subaerial erosion ; that without doubt such vallej'^s were formed 
following the post-Miocene uplift, or what is quite within the 
bounds of possibility earlier still, but that their final form. 
