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. 69-76.Clark, W.B. and Carlson, D.W., 1956, Mines and mineral resources of Amador County: California Division of Mines, California Journal of Mines and Geology, v. 52, p. 422.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.Irelan, W., Jr., 1888, Amador County, Keystone Consolidated Mining Company: California State Mining Bureau, 8th Annual Report of the State Mineralogist, p. 63-66.Logan, C.A., 1921, Mines and mineral resources of Amador County, Keystone Mine: California State Mining Bureau, 22nd Report of the State Mineralogist, p.411.Logan, C.A., 1934, Mother Lode gold belt of California: California Division of Mines Bulletin 108, p. 92-95.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.Storms, W.H., 1900, The Mother Lode region of California: California Mining Bureau Bulletin 18, p 77-78.Tucker, W.B., 1914, Mines and mineral resources of Amador County, Keystone Mine: California State Mining Bureau, 14th Report of the State Mineralogist, p. 34-36.Additional information on the Keystone Mine is available in file no. 339-1454 (CGS Mineral Reources Files, Sacramento).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J.E., 1983, The Geology and structural evolution of a portion of the Mother Lode Belt, Amador County, California: unpublished M.S. thesis, University of Arizona, 138 p.