66 The American Geologist. February, 1896 
hills are clearly shown to be older than the granite adjoining. 
As the contact is approached the granite becomes finer grained 
and is replaced by porphyritic dikes intersecting the highly 
metamorphosed sedimentary strata. 
Walcott lias described an Appalachian type of folding 
exhibited by the rocks of the White Mountain range.* The 
same structure is beautifully shown in Hunter's canon on tin- 
eastern slope of the Inyo range and less prominently in many 
other places. An apparent monoclinal structure was observed 
in several of the desert ranges which Mere not visited. This 
is most strikingly characteristic of the Pinto range lying east 
of the northern end of the Panamint valley. As viewed from 
the Argus range at Darwin it appears to be a monocline with 
an enormous thickness of strata whose truncated edges face 
the valley. 
There can be no doubt that the sedimentary strata of this 
whole section have been subjected to many and complex 
orographic movements. What is the origin of the folded 
structure? Did it result from the intrusion of the granite 
into the strata or from subsequent movements to which must 
be attributed the great hight and steep slope of these moun- 
tains? Judging from the manner in which the strata rest on 
or against the granite axes the folding in its important 
features dates from the earlier event, the later movements 
being due to faulting. The axes of the ranges in all proba- 
bility date from the period of the granitic intrusion. This 
must have been at least as late as post-Triassic, for according 
to Whitneyf Trfassic fossils occur in the Inyo range east of 
Independence. Whether or not it is to be correlated with the 
post-Jurassic granite of the Sierra Nevadas is not certain. 
Several of the ranges traversing this region are very precip- 
itous and strongly suggest the idea of faulted blocks. The 
eastern slope of the Inyo range is almost as high and steep ;is 
the corresponding slope of the Sierra Nevadas. The massive 
granite of this range and the metamorphic strata resting 
against it have the appearance of having been raised bodily. 
Should the folded structure be due to the forcing back of the 
strata along the line of granitic irruption it would differ in 
*Am. Jour, of Sei., March, 1895. 
fGeneral Geology of Cal., vol. i. p. 459. 
