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University of California. 



[Vol. i. 



fornia was greatly depressed and received a load of marine sedi- 

 ments at least a mile thick. (2) After the accumulation of the 

 series it was folded in a syncline, the southern limb of which has 

 been critically observed. This syncline has its axis approximately 

 normal to the trend of the coast. Near the ocean it has gentle dips, 

 but is sharply compressed and has high dips in the vicinity of 

 Scotia. (3) The base of the series, as seen in the Ferndale section, 

 must have been over a mile below sea level. It is now about 1,650 

 feet above that level. 



This diastrophism appears, thus, to involve at least three dis- 

 tinct movements: (1) From the nature of the beds of the Wild-cat 

 Series it is evident that the subsidence proceeded pari passu with 

 the accumulation of the sediments. The movement was probablv 

 local. The doctrine of isostacy teaches a direct causal relation 

 between the accumulation and the subsidence; but it is not clear 

 that the accumulation may not have been an effect rather than 

 a cause of the subsidence. (2) An orogenic movement which 

 deformed the terrane and tilted the strata. This orogenic move- 

 ment was local so far as the effects we are now considering are con- 

 cerned, but may have been simply a local manifestation of a wide- 

 spread orogenic activity inaugurated at the close of the Pliocene 

 sedimentation on the west coast. (3) The third movement was the 

 general or epeirogenic uplift of the coast. This movement, as has 

 been shown, effected the uplift of an extensive coastal peneplain. 

 This peneplain truncates the upturned edges of the Wild-cat strata 

 and forms their upper hypsometric limit. The terrane is, moreover, 

 terraced at various lower levels representing stages of the uplift. It 

 is thus clear that the orogenic deformation of the terrane antedates 

 the general uplift, and is separated from it by a portion at least of 

 the time occupied in the evolution of the coastal peneplain. The 

 fossils of the Wild-cat Series enable us to determine that the epeirog- 

 enic uplift of the coast was long subsequent to the deposition of 

 the California Pliocene. The recognition of an orogenic disturbance 

 following the accumulation of the Pliocene and antedating the epei- 

 rogenic uplift, suggests an explanation of some features of the 

 coastal geomorphy which would otherwise be difficult to account 

 for. If we suppose, and there is good warrant for the assumption. 



