REGION SOUTH OF GRANITE MOUNTAIN. 693 



Range, and, if any exists, it must be in very subordinate and unimport- 

 ant bodies. Opposite Carson Lake, on the east side' of the range, 

 granite forms the lower foot-hills, extending southward for several miles, 

 and rising abruptly out of the desert Quaternary sands. It is a rough 

 irregular-shaped mass, with the slopes frequently and deeply sulcated 

 by short rugged ravines; the principal canon, known as Sommer's Pass, 

 affording an accessible means of crossing the range. Still farther south- 

 ward, and separated from the last-mentioned body by only a few miles, 

 the granite again comes to the surface, stretching in an unbroken line along 

 the foot-hills beyond the limits of the map. Neither of these granite bodies 

 has been carefully studied. On the east side of the range, northeast from 

 Tarogqua Peak, there is still another small body of granite at the base of 

 the foot-hills, rising but a few hundred feet above the valley. Probably 

 all these masses of granite belong to one body, but their connection is 

 hidden by the heavy beds of Triassic quartzites and limestones, the older 

 nucleus only appearing as already described. Granite Mountain may be 

 regarded as roughly forming the axis of an anticlinal fold, dividing the 

 range into two distinct parts, the later beds dipping away from its mass 

 both to the northwest and southeast, and in the detailed observations to be 

 given the rocks will be first described from Granite Mountain southward, 

 and then from the north side of the peak northward to Humboldt Valley. 

 Directly south of the Archaean granite mass forming Granite Mount- 

 ain are observed a series of quartzitic strata, similar, in most respects, to 

 the inferior quartzites of the West Humboldt Range, which rest uncon- 

 formably against the granite mass, having a northeast strike and south- 

 east dip. These at the summit of McKinney's Pass are overlaid by lime- 

 stories resembling the lower limestone belt of Star Peak, but so far as 

 observed are devoid of fossils. T-hey continue the northeast strike of 

 the conformable underlying quartzites, and wrap around the granite mass, 

 with a gradual change of strike, somewhat in the manner of the lime- 

 stones of Wright's Canon, West Humboldt Range. Curving to the south, 

 this group of Triassic strata of about 4,000 feet thick reaches a north 

 and south strike, which they preserve for about 15 miles to the point of 

 their termination, where there is much faulting, local disturbance, and 



