SOUTHERN KLONDIKE HILLS, ECONOMIC GEOLOGY. 81 
luck of time did not permit their being mapped. Some faulting also 
occurred after the formation of the ore deposits in the northern part 
of the hills. The basalt northeast of Southern Klondike dips to the 
South. 
ECONOMIC GEOLOGY. 
GOLD AND SILVER. 
Gold and silver ores were discovered in the Cambrian rocks at South- 
ern Klondike in March, 1899, by J. G. Court and T. J. Bell. Since 
that time the prospects have been worked more or less continuously. 
It was while on a trip to these prospects in 1900 that J. L. Butler dis- 
covered the veins at Tonopah. From one group of claims shipments 
of ore ranging in value from $200 to $281 per ton and aggregating 
£50,000 are reported. Several thousand feet of tunnels, shafts, and 
inclines have been driven. In June, 1905, eight men were at work in 
the camp. 
The ore deposits are of three kinds — first, quartz veins which are 
parallel to the bedding of the Cambrian rocks, and which carry pre- 
dominant silver values; second, veins along the contact of the sedi- 
mentary rocks and rhyolite dikes, the values, about $15 per ton, being 
predominantly gold, and third, thin veins of quartz carrying silver- 
bearing galena and cerussite in granite along joint fractures parallel 
the bedding of the surrounding Cambrian rocks. The veins along 
ontacts apparently show post-mineral faulting. 
The quartz veins parallel to the bedding planes, which occur at and 
mile east of the village of Southern Klondike, are of greatest value 
tnd interest. These are tabular lenses of quartz, from a few inches to 
foot or more in thickness. Horses of limestone are included. Adja- 
ent veins connected by cross veins of quartz or completely separated 
y thin bands of limestone form in some instances mineralized zones 
1 feet thick. Quartz appears to have filled a fissure in the limestone, 
>recciation of the limestone having accompanied the fissuring. The 
ontact between the limestone and quartz is sharp, and important silici- 
ication of the limestone has not occurred. Vugs lined with acicular 
uartz crystals are rather characteristic. 
The original sulphides deposited simultaneously with the quartz and 
isseminated in small masses in it are, in the order of their abundance, 
[alena, copper sulphide,^ and iron pyrites. The secondary ores in- 
ude cerargyrite, chrysocolla with less malachite and azurite, specular 
ematite, and cerussite in brownish granular masses and to a less 
stent in crystals. These secondarv minerals surround the sulphides 
For a detailed description of this type see Spnrr. J. E.. Economic Geology, vol. 1, 100C>, 
>. 369-381'. 
[ h Stetefeldtite. according to J. E. Spurr, Trans. Am. Inst. Min. Eng., 1905, p. 961. 
Bull. 308—07 m 6 
