Mine detail: Rawhide Mine

Previously called 'Denton-Rawhide MineKennecott-Rawhide MineRawhide GroupRawhide Gold MineNevada New MinesGravelNorth BuckskinRegent HillSouth FortyBlack Eagle SouthwestHooligan HillMurray HillBalloon HillCrazy HillGrutt Hill'

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Location

Lat / long: 39.01408, -118.38624

Resource(B)

Primary: Gold, Silver
Secondary: Copper, Lead
Tertiary: Antimony, Molybdenum, Zinc, Chlorine, Bromine, Aluminum, Tungsten, Selenium, Mercury, Arsenic, Barium-Barite
Ore: Gold, Electrum, Silver, Embolite, Cerargyrite, Pyrargyrite, Argentite, Acanthite, Argentojarosite, Tetrahedrite, Proustite, Azurite, Chalcopyrite, Copper, Covellite, Galena, Scheelite, Chrysocolla, Malachite
Gangue: Quartz, Chalcedony, Chert, Kaolin, Calcite, Adularia, Alunite, Jarosite, Goethite, Hematite, Pyrrhotite, Pyrite
Orebody form: irregular lenses, veins, pod-type ore zones.
Discovery year: 1906

Production

Operation type: Surface-Underground
Deposit type: volcanic-hosted epithermal; veins; hydrothermal; shallow hot springs
Production size: Large
Development status: Producer
Production years: 1907-1920; 1990 - 2004
First production started: 1907
Last production ended: 2004

Geology

Host rock:pre-Esmeralda volcanic rocks(?)
Host type:Andesite,Rhyolite,Quartz Latite,Mixed Clastic/Volcanic Rock
Associated rock:pre-Esmeralda volcanic rocks(?)
Structure:The mine is located in a large caldera system along the northeast margin of the northwest-trending Walker Lane structural zone. The Miocene Rawhide volcanic center is 6.5 by 12km (4 x 7.5 mi.) in area., Three principal structural trends are recognized at Rawhide: 1) north-striking high angle faults, 2) northeast-striking moderate to high angle faults, and 3) an inferred northwest structural trend that is parallel to both the margin of the Rawhide volcanic center and the Walker Lane. North- and northeast -striking moderate to high angle faults are numerous but typically display only minor displacement. Most of the historic gold and silver production has come from veins that occupy these structures, but not all structures are mineralized and many display movement that postdates gold-silver deposition. Displacement on these structures appears to be primarily normal, although oblique-normal displacement is indicated locally by shallowly dipping slickensides. NE-trending structures control the emplacement of late lithic tuff dikes along the SW flanks of Murray and Balloon Hills and the southern flanks of Hooligan Hill. Two major N-S to NNE-trending high angle structures clearly bound and may offset ore grade mineralization at Murray and Crazy hills. Structures with NW trends are rarely exposed but an overall NW trend can be inferred from the alignment of ore zones, the northwesterly strike of tilted structural blocks, the orientation of the Balloon Hill rhyolite and other rhyolite dikes.
Tectonic:continental magmatic arc
Alteration processes:Rocks in the mine area have been affected by silicic, potassic, argillic, and advanced argillic alterations. Silicic alteration is characterized by an increase in quartz or other silica minerals in the host rock; the total silica content of the rock may or may not have increased. Quartz veins commonly accompany silicic alteration, but their presence is not diagnostic of silicic alteration. Rock hardness and resistance to erosion are the primary field criteria for recognizing silicic alteration. Silicic alteration preferentially affects the fine-grained matrix within fragmental host rocks such as the lithic tuff unit and the interstratified siltstone and volcanic breccia unit. More intense silicic alteration is characterized by the replacement of the fine-grained matrix of these rocks by a mosaic of coarser-grained quartz that commonly contains abundant minute rhombs of adularia. Intense silicic alteration results in rock containing only quartz, adularia, and pyrite (or limonite) in significant amounts. Silicic alteration is closely associated with gold ore in the Crazy Hill ore zone. All mineralized rock at rawhide has been potassically altered to some degree, as evidenced by the presence of adularia. The degree of potassic alteration can be adequately assessed only be microscopic identification of adularia and therefore is more difficult to recognize in the field. Three principal habits of adularia are recognized: 1) partial to complete replacement of primary feldspar phenocrysts, 2) overgrowth rims of adularia, and 3) small (typically 0.01-0.1 mm) euhedral rhombs associated with strong silicic alteration. Argillic alteration is characterized by the development of significant quantities of clay minerals (calcite) at the expense of groundmass, mafic minerals, and all phenocrysts except those of adularia and quartz, and apparently has resulted from numerous events including late supergene alteration related to the oxidation of sulfides. The dominant clay minerals formed include illite, kaolinite, and chlorite. Lesser amounts of mixed layer illite-smectites and montmorillonite are present. Argillic alteration is the dominant alteration type at Rawhide and forms a broad halo around more silicified and potassically altered rock, extending well beyond the limits of precious metal mineralization. Argillically altered rock is devoid of precious metal mineralization. The advanced argillic alteration mineral assemblage consists of kaolinite+alunite+quartz, chalcedony or opal. Advanced argillic alteration commonly occurs as irregular bleached zones up to a few inches thick along the margins of paragenetically late veins of kaolinite+alunite+chalcedony. It has only been recognized in oxidized portions of the deposit and may be related to lat

References

MRDSW016386
DEP10310397
Reference{Deposit:: Ross, D.C., 1961, Geology and Mineral Deposits of Mineral County, Nevada; NBMG Bull. 58. pp. 83-84.}{Deposit:: Vanderburg, 1937, Reconnaissance of Mining Districts in Mineral County, Nevada; USBM IC 6941. pp. 58-64.}{Deposit:: Lincoln, F.C., 1923, Mining Districts and Mineral Resources of Nevada; Nevada Newsletter Publishing Co.}{Deposit:: Mining and Scientific Press, Notes on Rawhide, Nevada; March 28, 1908}{Deposit:: Bates, James A., Nov. 1967, unpublished report on the Rawhide Lode-Placer Deposits in Mineral County, Nevada.}{Deposit:: Archibald, N.L., 1966, Industrial Mineral Deposits of Mineral County, Nevada: NBMG Report 14. p 30.}{Deposit:: Bonham, H.F. 1988, NBMG MI-1987}{Deposit:: Bonham, H.F. 1986, NBMG Map 91}{Deposit:: Bonham, H.F., 1986 NBMG Field Examination and Sample Analysis}{Deposit:: NBMG Mining District File #206, numerous press clippings 1986-1987.}{Deposit:: Plexus Resource Corp. 1986, Rawhide Gold Mine Report.}{Deposit:: Black, John E., 1988, Mineralization and Wallrock Alteration at the Rawhide Gold-Silver Deposit Mineral Co., Maste* Thesis, Stanford University.}{Deposit:: Black, John E., et al., 1991, Geology and Mineralization at the Rawhide Au-Ag Deposit, Mineral County, NV in Raines, G.L., et al., Eds., Geology and Ore Deposits of the Great Basin, The Geological Society of Nevada, Reno, p. 1123-1144.}{Deposit:: NBMG, 1991, The Nevada Mineral Industry-1990, NBMG Special Publication MI-1990, p.16 and 23.}{Deposit:: Mining Journal/ Montagu Mining Finance, Minindatabase, 8/10/91.}{Deposit:: NBMG, 1994, MI-1993}{Deposit:: Nevada Division of Minerals, 1994}{Deposit:: The Mining Record April 28,1993}{Deposit:: Long, K.R., DeYoung, J.H., Jr., and Ludington, S.D., 1998, Database of significant deposits of gold, silver, copper, lead, and zinc in the United States; Part A, Database description and analysis; part B, Digital database: U.S. Geological Survey Open-File Report 98-206, 33 p., one 3.5 inch diskette.}
ReporterLaPointe, D.D., Schruben, Paul G.