Mine detail: Democrat Lode

Previously called 'John Mitchell Lode'

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Location

Lat / long: 64.33357, -146.35674

Resource(M)

Primary: Gold
Ore: Arsenopyrite, Gold, Pyrite, Stibnite
Gangue: Ankerite, Muscovite, Quartz

Production

Operation type: Unknown
Development status: Producer

Geology

Host type:Rhyolite
Associated type:Rhyolite
Alteration processes:Areas of the rhyolite at the Democrat Lode exhibit several types of alteration. The lode contains fractures filled with gossanized quartz veins with voids and localized sericite. McCoy and others (1997) describe several stages of alteration at the Democrat Lode. An early stage of alteration consists of quartz-tourmaline-muscovite +/- biotite +/- K-spar +/- clinozoisite. The stage more commonly associated with gold is an assemblage of quartz-white mica +/- ankerite +/- carbonaceous material. Albite is present in veins with quartz (R.J. Newberry, oral communication, 1998). The surrounding gneiss displays evidence of hornfelsing (K. Ausburn, oral communication, 1998).

References

MRDSA012486
DEP10001704
Reference{Deposit:: Ellsworth, C.E., and Parker, G.L., 1911, Placer mining in the Yukon-Tanana region: U.S. Geological Survey Bulletin 480, 325 p.}{Deposit:: Prindle, L.M., and Katz, F.J., 1913, Detailed description of the Fairbanks district, in Prindle, L. M., A geologic reconnaissance of the Fairbanks quadrangle, Alaska: U.S. Geological Survey Bulletin 525, p. 59-152.}{Deposit:: Saunders, R.H., 1965, A geochemical investigation in the Richardson area, Big Delta quadrangle, Alaska: Alaska Division of Mines and Minerals Geochemical Report 3, 11 p.}{Deposit:: Bundtzen, T.K., and Reger, R.D., 1977, The Richardson lineament-a structural control for gold deposits in the Richardson mining district, Alaska: Alaska Division of Geological and Geophysical Surveys Geologic Report 55, 46 p.}{Deposit:: Eberlein, G.D., Chapman, R.M., Foster, H.L., and Gassaway, J.S., 1977, Map and table describing known metalliferous and selected nonmetalliferous mineral deposits in central Alaska: U.S. Geological Survey Open-File Report 77-168-D, 132 p., 1 map, scale 1:1,000,000.}{Deposit:: Weber, F.R., Foster, H.L., Keith, T.E.C., Dusel-Bacon, C., 1978, Preliminary geologic map of the Big Delta quadrangle, Alaska: U.S. Geological Survey Open-File Report 78-529A, 1 sheet, scale 1:250,000.}{Deposit:: Menzie, W.D., and Foster, H.L., 1979, Metalliferous and selected nonmetalliferous mineral resource potential in the Big Delta quadrangle, Alaska: U.S. Geological Survey Open-File Report 78-529D, 61 p., 1 sheet, scale 1:250,000.}{Deposit:: Cobb, E.H., and Eberlein, G.D., 1980, Summaries of data on and lists of references to metallic and selected nonmetallic mineral deposits in the Big Delta and Tanacross quadrangles, Alaska: U.S. Geological Survey Open-File Report 80-1086, 77 p.}{Deposit:: Metz, P.A., and Hawkins, D.B., 1981, A summary of gold fineness values from Alaska placer deposits: University of Alaska, Fairbanks, Mineral Industry Research Laboratory Report No. 45, 63 p.}{Deposit:: Swainbank, R.C., Burton, J.P., and Metz, P.A., 1984, Bedrock geology of the Richardson mining district, Alaska: University of Alaska, Mineral Industry Research Laboratory Open-File Report 84-2, 60 p., 8 maps, scale 1:40,000.}{Deposit:: Olson, B.G., Burton, J., Wolff, E.N., and Swainbank, R.D., 1985, Mining and minerals in the golden heart of Alaska: Fairbanks North Star Borough Publication, 80 p.}
ReporterCameron S. Rombach