Mine detail: Gold Hill Deposit

Previously called ''

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Location

Lat / long:

38.77255, -117.05165

Resource(B)

Primary:	Gold, Silver
Tertiary:	Tungsten, Arsenic, Antimony, Thallium, Mercury, Molybdenum, Fluorine-Fluorite, Manganese
Ore:	Gold, Electrum, Pyrite, Quartz, Adularia, Sericite, Hematite, Limonite, Alunite, Jarosite, Illite, Montmorillonite, Kaolinite, Fluorite, Realgar, Scorodite
Gangue:	Clay
Orebody form:	tabular
Discovery year:	1910

Production

Operation type:	Surface-Underground
Deposit type:	disseminations; veins; sheeted zones
Production size:	Small
Development status:	Producer
Production years:	1910-1942; 1950-1964
First production started:	1910
Last production ended:	1960

Geology

Host rock:	Mount Jefferson Caldera
Host type:	Ash-Flow Tuff,Rhyolite
Associated rock:	Shoshone granite pluton
Associated type:	Granite,Metasedimentary Rock
Structure:	Northwest-striking faults and joints; a WNW-trending paleotopographic high, may represent the margin of buried caldera located SW of Round Mountain., Ore deposits are localized by a NW-trending lineament.
Alteration processes:	Propylitization and argillization of host rocks are intense. Adularia replacement of K-feldspars and plagioclase is associated with ore. Plagioclase and groundmass are replaced with quartz and sericite. Within propylitically altered rock, biotite is partially or wholly altered to chlorite. Groundmass is altered to chlorite +/- clay +/- carbonate+/- epidote. Plagioclase phenocrysts are altered to sericite (illite) as small points, clots, and veinlets along cleavage planes. Argillically altered rock contains no unaltered biotite or plagioclase, both phases being altered to clay (illite, montmorillonite, kaolinite) and sericite. Groundmass is entirely composed of fine-grained clays and sericite. Quartz-adularia silicification is widespread along the veins. Degree of silicification, sericite + argillic alteration increases with (higher) elevation. Fine-grained secondary quartz has replaced original plagioclase feldspars, occurs as clots in the groundmass, and as hairline veinlets that lace the rock.

References

DEP	10310493
Reference	{Deposit:: Giancola, 1998}{Deposit:: Harding 2004c}{Deposit:: Kinross Gold Corp., 2004a}{Deposit:: Kleinhampl and Ziony, 1984}{Deposit:: Nevada Bureau of Mines and Geology, 1999, 2000, 2001, 2003.}{Deposit:: Nevada Star Resources Corp. Annual Report, 2004}{Deposit:: Tingley, 1998}{Deposit:: United States Bureau of Land Management, 1978k}{Deposit:: United States Bureau of Mines, 1995}{Deposit:: United States Geological Survey, 1971a.}{Deposit:: Nevada Star Resource Corp. press release, 7/2/2003}{Deposit:: Nevada Star Resource Corp. website, Dec. 2005, http://www.nevadastar.com/s/GoldHillProject.asp}
Reporter	LaPointe, D.D., Schruben, Paul G.