Show MINING DISTRICTS OF NEVADA the results of reconnaissance work in nevada by F L ransome have been published by the united states geological survey as bulletin notes on oil some mining districts in humboldt county nev the bulletin embodies the results of a recon reconnaissance nals examination of some square miles including the seven troughs rosebud star unionville Uni onville humboldt pitting chafey kennedy adelaide red butte and coppereid Cop districts some of the districts examined such as seven troughs rosebud and red butte have been prospected only within the last decade others like star city and unionville Uni onville reached their acme of productiveness in the sixties and have not yet participated in the recent general revival of mining activity in nevada one or two like chafey have received new names and have been exploited in various ways that modern experience and ingenuity have devised for this purpose still others like adelaide have been intermittently active for over thirty five years oscillating between prosperity and decay mr ransome discusses the mineralogy geology and mining operations I 1 of the region his conclusion is that the southern portion of hum holdt county is part of a province characterized chiefly by the prevalence of ores of silver with numerous and widely scattered deposits of stibnite and cinnabar there are in addition some deposits of gold silver copper and nickel cobalt ores ore deposition probably began immediately after the intrusion of the triassic and jurassic sediments in n late mesozoic time by a igneous rock of the same kind as that which invaded the sedimentary rocks of the sierra nevada at the same period and continued into the tertiary the known tertiary dep deposits are essentially gold silver ores and co copper ores but it is possible that some of the other types are also tertiary |