| Lat / long: | 38.77255, -117.05165 |
| 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 |
| 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 |
| 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. |
| 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. |