GOLD MOUNTAIN RIDGE AND HILLS NEAR BY. 
Juniper and pinon cover the crest of the Gold Mountain ridge, the 
timber line being on the 6,'200-foot contour on the south and on the 
G,700-foot contour on the north side of the ridge. Yucca groves are 
sporadically distributed over the rhyolite and basalt flows to the 
south of the main ridge, while a fair growth of grass covers Gold 
Mountain and the surrounding hills. The main ridge on which 
Gold Mountain is situated is well watered. Tunnels and wells in the 
vicinity of Old Camp strike water at depths varying from 50 to 75 
feet. The water in some cases appears to flow from crevices in gran- 
ite and in others to seep from the overlying soil. Two wells located 
in Cambrian sedimentary rocks 1 mile east and northeast of Tokop 
are about 20 feet deep. The water is said to come from rock crevices. 
The water of Sand Spring, west of the boundary of the area here 
discussed, in Death Valley, is rather strongly impregnated with sul- 
phur, but is nevertheless usable. 
GENERAL GEOLOGY. 
The formations exposed in the Gold Mountain ridge and the adja- 
cent hills, from the base up, are as follows: Cambrian sedimentary 
rocks, quartz-monzonite porphyry, post-Jurassic granite, pre-Tertiary 
diorite porphyry, rhyolite, and basalt. 
# SEDIMENTARY ROCKS. 
Cambrian. — Cambrian rocks form the rugged ridge northeast of 
Tokop and the western front of the ridge facing Death Valley. A 
thin band of Cambrian rocks rims the southern border of the gran- 
ite batholith which forms the central portion of the main ridge. 
These narrow Cambrian masses between the granite and the Tertiary 
rhyolite are due to the fact that resistance to late Mesozoic and early 
Tertiary erosion was greater in the granite and the adjacent meta- 
morphosed Cambrian rocks than in the unmetamorphosed Cambrian 
rocks. Large inclusions of Cambrian schist and metamorphosed 
limestone are sporadically distributed in the granite, while small 
fragments are widely distributed in both granite and rhyolite. 
The Cambrian rocks of the Gold Mountain ridge include inter- 
bedded metamorphosed shales and impure limestones and calcareous 
sediments. The amount of metamorphism suffered by these rocks 
decreases w T ith increase of distance from the granite batholith. Argil- 
laceous rocks are widely distributed, although they do not appear to 
be present at the extreme west end of the range. They include fine- 
grained, well-banded slates of black to light-gray color and biotite 
schists both with and without knotlike aggregates of biotite. 
Limestone and calcareous sediments are represented by white and 
gray marbles of medium to coarse grain and by lime-silicate rocks 
in which brown garnet, vesuvianite, epidote, tremolite, chlorite, and 
