168 



GUIDEBOOK OF THE WESTERN UNITED STATES. 



From the small tovm of Palisade the narrow-gage Eureka & Pah- 

 sade Hailroad runs to Eureka/ one of the most famous of the old 



es to the south. 



Palisade, 



mmmg camps 



of Nevada, 80 



mi 



Elevation 4,514 feet. 

 Population 242.* 

 Omaha 1,257 miles. 



The narrow-gage line goes u^) Pine Creek, the mouth 



of which is passed just beyond the tunnel at Palisade. 



Pine Creek valley trends due north, and irrigated 



lands lie along it for 30 to 35 miles. 

 Below Palisade the route continues dovra the canj^on, which is 

 wider and bounded by less steep walls than east of this. town. The 

 lavas, Avhich all look much alike in general aspect, are cliiefiy basalt 



The first claims in the Eureka camp 

 * located in 1864, but it was not until 



1869 that the Eureka mine was developed 

 on Ruby Hill. From that time until the 

 early eighties this was the most active 

 mining camp in Nevada and had a popii- 

 lation of about 6,000. Between 1869 and 

 1883 the district yielded $60,000,000 in 

 bullion, about one-third gold and two- 

 thirds silver, and about 225,000 short tons 

 of lead. After 1878 the production de- 

 clined. "The lead ores constituted the 

 main source of gold and silver until 1910, 

 since when the greater part of the precious 

 metalrf has been derived from milling ore 

 containing little or no lead. 



rhyolite, and basalt) breaking up to the 

 surface along certain of the larger faults. 

 The Ruby Tlill ore deposits were found 

 in a roughly V-shaped mass of shattered 

 limestone between the main Ruby lUll 

 fault and a branch fault which for the 

 most part followed the contact of the 

 limestone with quartzite. The shapes of 

 some of the ore bodies suggest that they 

 were formed by replacement along frac- 

 tureSj but as a whole they are very irregu- 

 lar. The minerals originally deposited 

 in the limestone were pyrite, arsenopy- 

 rite, galena, and zinc blende, with minor 

 amounts of molybdenite and other min- 

 erals, but the bulk of the ore mined was 



The Eureka district comprLses a rough, oxidized nearly down to ground-water 



almost completely isolated mountain 



and it is doubtful if within the 

 Great Ba^in pro\'ince there can be found 

 any region of equally restricted area sur- 

 pa.s.sing it in its exposures of Paleozoic 

 formations, especially those of the lower 

 and middle Paleozoic systems. The sed- 

 imentary formations represent all siges 

 from Lower Cambrian to Pennsylvanian 

 (see table on p. 2) and have a total thick- 

 ness of 30,000 feet. 



In post -Jurassic time the strata in this 

 district, as elsewhere in Nevada, were 



^ 



crumpled into a scries of folds, some of 

 them with very steep sides. The folding 

 was followed by intense faulting. The 

 more profound faults had a general 

 northerly trend, and there were branches 



or connecting 



faults of northwesterly 

 trend. Next came a long period of ero- 

 sion. Tertiar>^ time was marked by 



great volcanic activity, lavas (andesite, 



level, which ranged from 600 to 1,100 feet 

 below the surface. One of the principal 

 kinds of ore, known as *^red carbonate/' 

 was composed of a hydrous iron oxide 

 mixed with sulphate and carbonate of 

 lead and inclosing residual lumps of ga- 

 lena. Most of it carried gold and silver 

 to the amount of $25 to $50 of each to the 

 ton. In some of the ore, however, the 

 gold was worth much more than the silver. 



Several of the ore bodies in Pro:^ect 

 Mountain contained a large amount of 

 quartz and a relatively larger proportion 

 of gold to silver, with less lead. Some 

 contained bismuth and tellurium. 



According to J. S. Curtis, who studied 

 the deposits in 1881 and 1882, the ores 

 were deposited by hot volcanic waters 

 which ascended along the fissures after the 

 rhyolite eruptions, Curtis assumed that 

 these waters had leached the metals from 

 some deep-seated rock. 



