California · Amador County
Past Producer

Central Eureka Mine

Amador County, California, United States
GoldSilver
⌖ Show on mapUSGS source ↗
Commodities
PrimaryGold
SecondarySilver
Commodity typeM
Deposit
Deposit typeHydrothermal vein
Model273: Low-sulfide Au-quartz vein
Orebody formTabular, pinch and swell
Ore controlOre shoots within mesothermal gold-bearing quartz veins, and as disseminated auriferous sulfides in greenstone\n\n
Materials
Ore mineralsGold, Pyrite, Arsenopyrite
GangueSlate
Geology
Host rockSlate,Greenstone · Mariposa Formation
StructureBear Mountains Fault zone, Melones Fault zone
Tectonic settingMagmatic arc
AlterationWall rocks hydrothermally altered, having been partially to completely converted to ankerite, sericite, quartz, pyrite, arsenopyrite, chlorite, and albite. Locally, greenstone bodies adjacent to the quartz veins contain enough disseminated auriferous pyrite in large enough bodies to constitute low-grade ore.
Economic & production
Development statusPast Producer
Discovery year1855
Identification
Deposit ID10310599
Alternate namesSummit Mine
RegionNA
Data scoreA
Coordinates38.38284, -120.79792
References
Carlson, D.W., and Clark, W.H., 1954, Mines and mineral resources of Amador County, California: California Division of Mines and Geology, 50th Report of the State Mineralogist, p. 173-177.Clark, W. B., 1970, Gold districts of California: California Divisions of Mines and Geology Bulletin 193, p. 69-77.Duffield, W.A. and Sharp, R.V., 1975, Geology of the Sierra foothills melange and adjacent areas, Amador County, California: U.S. Geological Survey Professional Paper 827, 30 p.Logan, C.A., 1921, Amador County, Central Eureka Mine: California State Mining Bureau, 17th Report of the State Mineralogist, p. 409-410.Logan, C.A., 1927, Amador County, Central Eureka Mine: California State Mining Bureau, 23rd Report of the State Mineralogist, p. 158-165.Logan, C.A., 1934, Mother Lode gold belt of California: California Division of Mines Bulletin 108, p. 74-80.Schweickert, R.A., Hanson, R.E., and Girty, G.H., 1999, Accretionary tectonics of the Western Sierra Nevada Metamorphic Belt in Wagner, D.L. and Graham, S.A., editors, Geologic field trips in northern California: California Division of Mines and Geology Special Publication 119, p. 33-79.Spiers, J., 1931, Mining methods and costs at the Central Eureka Mine, Amador County, California: Bureau of Mines Information Circular 6512, 13 pp.Storms, W.H., 1900, The Mother Lode region of California: California Mining Bureau Bulletin 18, p 64-65.Tucker, W.B., 1914, Amador County, Central Eureka (Summit) Mine: California State Mining Bureau, 14th Annual Report of the State Mineralogist, p. 24.Zimmerman, J.E., 1983, The Geology and structural evolution of a portion of the Mother Lode Belt, Amador County, California: unpublished M.S. thesis, University of Arizona, 138 p.Additional information on the Central Eureka Mine is available in file no. 322-5941 (CGS Mineral Reources Files, Sacrament)o.