Oscillations of the Colifornia Coast. — Fairbanks. 219 
with, the orogenie or local, and the epeirogenic or general up- 
lift. Is it possible to discriminate the two ert'ects? Certain 
striking facts suggest an answer to this question in the atfir- 
inative. The orogenie uplift preceded the epeirogenic, and 
there was an interval between tlie movements iii which a great 
denutiation was affected." It will be evident from these quo- 
tations that it is exceedingly difficult to get at what professor 
Lawson's ideas really are on this question. His general mean- 
ing seems to be, aside from the discrepancies, that the post-Plio- 
cene movements were purely of the nature of upthrusts of local 
fault blocks portions of which remained at or below the orig- 
inal level, and that the geography of the coast was not alfect- 
ed at all. The epeirogenic uplift referred to is that of the 
last iiplift giving rise to the terraces. I cannot see what there 
is about the phenomena of these recent movements of the coast 
of California which makes it necessary to assume such pecu- 
liar mountain making disturbances, so different from the us- 
ual character of such events. 
The views of professor Lawson in his different papers, al- 
though showing numerous contradictions, the earlier ones re- 
maining unmodified in the later, may be generalized as fol- 
lows. For the coast as a whole no marked disturbance ap- 
pears to separate the Pliocene from the Pleistocene, a depres- 
sion with transgression of the sea during the former, and a 
gradual re-elevation through the latter. Marked disturban- 
ces are recognized as having taken place locally, but without 
affecting any general elevation of the coast; while on the San 
Francisco peninsula a depression is recognized at the time of 
the disturbance or immediately following it. The San Bruno 
fault block is excepted, it having undergone a period of ero- 
sion before the deposition of the terrace formations. The 
history which professor Lawson thus recognizes as having been 
characteristic of San Bruno mountains I believe is character- 
istic of the whole coast. 
Mr. George Ashley* clearly distinguished a period of land 
erosion between the formation of the Merced sesies and the 
Pleistocene terraces as the following quotation will show. 
"The arguments from the structural side are, that while, as 
shown by the fauna, this formation (Upper Merced beds) is 
*Proc. Cal. Acad. Sci., Ser. 2, Vol. V, p. 334. 
