224 The American Geoloijist. October, 1897 
ing been att'ected by an erogenic disturbance which threw the 
Pliocene peneplain into "orographic blocks and anticlinal ar- 
ches," but without any accompanying uplift. The evidence 
for no uplift will have to be made much stronger than it ap- 
pears from the description given, before it can be used to off- 
set the result of many lines of research all of which point to 
a very considerable uplift following the post-Pliocene disturb- 
ance the whole length of California. It is difficult to under- 
stand also how the Pliocene peneplain could have remained in 
a distinguishable condition after the beds of that age in the 
same region had been so generally deformed. 
According to professor Lawson* the Pliocene is extensively 
developed in thehillsback of Berkeley, east of San Francisco 
bay. The beds have been quite sharply folded and are briefly 
referred to in part as follows. f "The Pliocene rocks were all af- 
fected by sharp orogenic deformation prior to the general uplift 
of the coast." He mentions an "uplifted coastal peneplain" in 
these hills whose average elevation is about 15G0 feet, but whet- 
her due to wave action or subaerial erosion is not stated. It is 
impossible to believe that in the Berkeley hills the post-Plio- 
cene disturbance which so steeply tilted and faulted the Plio- 
cene beds found there should not have elevated them above 
the sea and subjected them to a period of subaerial erosion 
before the depression took place in the recovery from which 
the terraces were formed. 
Turner]; has shown that mount Diablo was elevated at the 
close of the Pliocene and that the Pleistocene deposits lie un- 
conformably upon the rocks of the former period. 
Enough geological work has been done in the Coast Eanges 
to show that the post- Pliocene disturbances were not local 
but affected in varying degree the whole coast; that with this 
mountain-making process there was also associated a general 
uplift. The fact of a disturbance and elevation at the close 
of the Miocene is not questioned by any geologist and there is 
no valid reason for doubting that the similar phenomena mark- 
ing the close of the Pliocene were due to similar causes. I 
cannot see anything in the nature of the phenomena present- 
*Bull. Dpi. of Geol., Univ. of Calif., Vol. II, p. 94. 
tBull. Dpt. of Geol., Univ. of Calif., Vol. I, p. 268. 
JBull. Geo., Soc. of Am., Vol. II, p. 402. 
