Little Clearwater lode (ARDF #MH046) Cu

Little Clearwater lode

Occurrence, Inactive

Commodities and mineralogy

Main commodities	Cu
Other commodities	Ag
Ore minerals	chalcocite; chalcopyrite; malachite
Gangue minerals	calcite; quartz

Geographic location

Quadrangle map, 1:250,000-scale	MH
Quadrangle map, 1:63,360-scale	A-6
Latitude	63.1492
Longitude	-146.8837
Nearby scientific data	Find additional scientific data near this location
Location and accuracy	The Little Clearwater lode is at an elevation of about 4,850 feet about 0.7 mile southwest of peak 5315 at the south end of the Clearwater Mountains; it is in the SE1/4SE1/4 section 24, T. 20.S., R. 4 E., Fairbanks Meridian. The occurrence corresponds to locality A36 of Kurtak and others (1992), locality 3 in figure 4 of Cobb (1979 [OFR 79-238]), and locality 6 in table 2 of Nokleberg and others (1991).

Geologic setting

Geologic description The rock at the occurrence is propylitized basalt of the Nikolai Greenstone of Late Triassic age (Nokleberg and others, 1991). The deposit consists of copper-bearing quartz-calcite veins in the weakly altered basalt. Reported copper minerals are chalcopyrite, chalcocite, and malachite. Sample 1414 from metabasalt assayed 0.34 ounce of silver per ton and 1.08 percent copper; gold is present in a near-background amount (10 parts per billion) (Kurtak and others, 1992, table A32, p. 165).
Geologic map unit	(-146.885962897574, 63.1487580710163)
Mineral deposit model	Basaltic Cu (Cox and Singer, 1986; model 23).
Mineral deposit model number	23
Age of mineralization	The deposit is probably either Cretaceous or early Tertiary in age (see MH060, MH087, or MH100).
Alteration of deposit	Propylitic alteration.

Production and reserves

Workings or exploration	U.S. Bureau of Mines sample 1414 contained 1.08 percent copper and 0.34 ounce of silver per ton (Kurtak and others, 1992, table A32).
Indication of production	None
Additional comments The mineralized zones are small and mostly in rubble.

References

References Clautice, K.H., Smith, T.E., Pessel, G.H., and Solie, D.N., 1989, Geology and mineral occurrences, upper Clearwater Creek area, Mt. Hayes A-6 quadrangle, Alaska: Alaska Division of Geological and Geophysical Surveys Public-data File 89-18, 14 p., 2 sheets, scale 1:24,000. Cobb, E.H., 1979, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Mount Hayes quadrangle, Alaska: U.S. Geological Survey Open-File Report 79-238, 140 p. Nokleberg, W.J., Lange, I.M., Roback, R.C., Yeend, Warren, and Silva, S.R., 1991, Map showing locations of metalliferous lode and placer mineral occurrences, mineral deposits, prospects, and mines, Mount Hayes quadrangle, eastern Alaska Range, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-1996-C, 42 p., 1 sheet, scale 1:250,000. Smith, T.E., Trible, T.C., and Stein, D.R., 1973, Analyses of rock and stream-sediment samples, Mt. Hayes A-6 quadrangle, south-central Alaska: Alaska Division of Geological and Geophysical Surveys Geochemical Report 26, 1 plate, scale 1:63,360.
Reporters	W.T. Ellis (Alaska Earth Science), C.C. Hawley (Hawley Resource Group), and W.J. Nokleberg (USGS)
Last report date	8/5/2001