Unnamed (southeast of upper Berg Creek) (ARDF #JU012) Cu

Unnamed (southeast of upper Berg Creek)

Occurrence, Inactive

Commodities and mineralogy

Main commodities	Cu
Ore minerals	chalcopyrite; pyrite

Geographic location

Quadrangle map, 1:250,000-scale	JU
Quadrangle map, 1:63,360-scale	D-5
Latitude	58.9325
Longitude	-135.6546
Nearby scientific data	Find additional scientific data near this location
Location and accuracy	This occurrence is at an elevation of about 2,500 feet, 2.5 miles southeast of Berg Mountain on the east side of the Berg Creek drainage. It is in the SE1/4 section 12, T. 34 S, R. 58 E. of the Copper River Meridian. This is location J016 of Wells and others (1986). The location is accurate within 1/2 mile.

Geologic setting

Geologic description The rocks in the vicinity of this occurrence are predominantly Silurian and Devonian greenstones and other metavolcanic rocks (Brew and Ford, 1985). Cobb (1978 [OFR 78-374]) reports that a boulder containing pyrite and chalcopyrite was found in glacial moraine at this location. The rocks in the vicinity of this occurrence are deformed and metamorphosed Silurian or Devonian carbonate, clastic and volcanic clastic units that have been intruded by Upper Jurassic and Lower Cretaceous granitic and dioritic rocks (Brew and others, 1992).
Geologic map unit	(-135.656460479045, 58.9321481619551)

Geologic description

The rocks in the vicinity of this occurrence are predominantly Silurian and Devonian greenstones and other metavolcanic rocks (Brew and Ford, 1985). Cobb (1978 [OFR 78-374]) reports that a boulder containing pyrite and chalcopyrite was found in glacial moraine at this location.

The rocks in the vicinity of this occurrence are deformed and metamorphosed Silurian or Devonian carbonate, clastic and volcanic clastic units that have been intruded by Upper Jurassic and Lower Cretaceous granitic and dioritic rocks (Brew and others, 1992).

Geologic map unit

(-135.656460479045, 58.9321481619551)

Production and reserves

Indication of production	None

References

References Brew, D.A., and Ford, A.B., 1985, Preliminary reconnaissance geologic map of the Juneau, Taku River, Atlin, and part of the Skagway 1:250,000 quadrangles, southeastern Alaska: U.S. Geological Survey Open-File Report 85-395, 23 p., 2 sheets, scale 1:250,000. 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. Cobb, E.H., 1978, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Juneau quadrangle, Alaska: U.S. Geological Survey Open-File Report 78-374, 155 p. MacKevett, E.M., Jr., Brew, D.A., Hawley, C.C., Huff, L.C., and Smith, J.G., 1971, Mineral resources of Glacier Bay National Monument, Alaska: U.S. Geological Survey Professional Paper 632, 90 p., 12 plates, scale 1:250,000. 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