Unnamed (west of Mt. Elder) (ARDF #JU003) Cu, Mn

Unnamed (west of Mt. Elder)

Occurrence, Inactive

Commodities and mineralogy

Main commodities	Cu; Mn
Ore minerals	psilomelane; pyrite; secondary cu mineral

Geographic location

Quadrangle map, 1:250,000-scale	JU
Quadrangle map, 1:63,360-scale	D-6
Latitude	58.9785
Longitude	-135.8536
Nearby scientific data	Find additional scientific data near this location
Location and accuracy	This occurrence is on the west side of Mt. Elder at an elevation of about 3,700 feet. It is in the SE1/4 section 26, T. 33 S., R. 57 E. of the Copper River Meridian. It is location number J002 of Wells and others (1986). The location is accurate within 1/2 mile.

Geologic setting

Geologic description Wells and others (1986) describe this deposit as psilomelane, pyrite, and secondary Cu minerals in a siliceous gangue associated with volcanic rocks. No other information is available. The area is underlain by deformed and metamorphosed Silurian or Devonian carbonate, clastic and volcanic clastic rocks that have been intruded by Upper Jurassic and Lower Cretaceous granitic and dioritic rocks (Brew and others, 1992). The host country rocks at the occurrence are metamorphosed Silurian and Devonian graywacke and argillite that have been intruded by non-foliated Cretaceous and Tertiary granodiorite (Brew and others, 1978).
Geologic map unit	(-135.855483203369, 58.9781201893545)

Geologic description

Wells and others (1986) describe this deposit as psilomelane, pyrite, and secondary Cu minerals in a siliceous gangue associated with volcanic rocks. No other information is available. The area is underlain by deformed and metamorphosed Silurian or Devonian carbonate, clastic and volcanic clastic rocks that have been intruded by Upper Jurassic and Lower Cretaceous granitic and dioritic rocks (Brew and others, 1992). The host country rocks at the occurrence are metamorphosed Silurian and Devonian graywacke and argillite that have been intruded by non-foliated Cretaceous and Tertiary granodiorite (Brew and others, 1978).

Geologic map unit

(-135.855483203369, 58.9781201893545)

Production and reserves

Indication of production	None

References

References Brew, D.A., Himmelberg, G.R., Loney, R.A., and Ford, A.B., 1992, Distribution and characteristics of metamorphic belts in the southeastern Alaska part of the North American Cordillera--Metamorphic styles in young and ancient orogenic belts: Journal of Metamorphic Geology, v. 10, no. 3, p. 465-482. Brew, D.A., Johnson, B.R., Grybeck, D., Griscom, A., Barnes, D.F., Kimball, A.L., Still, J.C., and Rataj, J.L., 1978, Mineral resources of the Glacier Bay National Monument Wilderness Study Area, Alaska: U.S. Geological Survey Open-File Report 78-494, 670 p., 7 sheets. Wells, D.E., Pittman, T.L., Brew, D.A. and Douglass, S.L., 1986, Map and description of the mineral deposits in the Juneau, Taku River, Atlin, and part of the Skagway quadrangles, Alaska: U.S. Geological Survey Open-File Report 85-717, 332 p., 1 sheet, scale 1:250,000.
Reporters	J.C. Barnett and L.D. Miller (Juneau, Alaska )
Last report date	12/15/2001