SLATE RIDGE, SEDIMENTARY ROCKS. 
achite, azurite, and coral-red opaline quartz, heavily stained by 
manganese dioxide, is a streak from 1J to 2 inches wide of a canary- 
yellow granular mineral which appears to replace limestone. Di 
W. F. Hillebrand determined this mineral to be chloropal, a hydrous 
iron silicate. The general resemblance in structural relations and 
mineralogic composition of these deposits to those near the granite of 
the Belted Range at Oak Spring is worthy of note. The nearest 
water to these prospects is at Sand Spring, 6 miles away, and fuel 
can be obtained from Gold Mountain within 10 miles. By road the 
prospects are 45 miles from the railroad terminus at Goldfield. 
SLATE RIDGE, 
TOPOGRAPHY AND GEOGRAPHY. 
Slate Ridge lies between the valley south of Mount Jackson on the 
north and Oriental -Wash and an opposed westward-reaching arm 
of Sarcobatus Flat on the south. The ridge trends a little north of 
east, and near its middle is almost severed by opposed gravel-filled 
valleys. West of the Stateline Mill the ridge is formed of a number 
of low domelike granite hills, which reach a maximum. elevation of 
0,500 feet. The hills are rather gently sloping and without promi- 
nent rock exposures. From a distance they are yellowish gray in 
color. East of the Stateline Mill the rocks are largely of sedimen- 
tary origin and there is a sharp crest line. The east end of Slate 
Ridge is a mesa of lava flows which have been considerably dis- 
sected. The range is covered by a sparse growth of tree yucca and 
a little grass grows throughout its extent. 
GENERAL GEOLOGY. 
The formations exposed in Slate Ridge, from the oldest to the 
youngest, are the following: Cambrian sedimentary rocks, post- 
Jurassic granite, pre-Tertiary quartz-monzonite porphyry, pre-Ter- 
tiary diorite porphyry, earlier rhyolite, later rhyolite, and basalt. 
SEDIMENTARY ROCKS. 
Cambrian. — Cambrian rocks form the central part of Slate Ridge 
and occur in numerous areas isolated in the granite in its west end. 
Of the latter some are clearly inclusions buoyed up by the granite 
magma, while others may perhaps be connected with larger masses 
beneath the surface. Small Cambrian fragments are abundantly 
included in granite and the earlier rhyolite, particularly near the 
contact of these rocks with the sediments. 
The Cambrian rocks of Slate Ridge are little metamorphosed 
the road between Tokop and Goldfield. Here the interbedded series 
consists of paper-thin olive-green shales, gray limestones, or ma 
