Unnamed (north of White Glacier) (ARDF #JU055) Au, Cu, Mo, Pb, Zn

Unnamed (north of White Glacier)

Occurrence, Inactive

Commodities and mineralogy

Main commodities	Au; Cu; Mo; Pb; Zn
Ore minerals	pyrite

Geographic location

Quadrangle map, 1:250,000-scale	JU
Quadrangle map, 1:63,360-scale	D-6
Latitude	58.8255
Longitude	-135.9246
Nearby scientific data	Find additional scientific data near this location
Location and accuracy	This occurrence is at an elevation of about 3,300 feet, approximately 2 miles east-northeast of Mt. Case and 1.5 miles north of the White Glacier. It is in the NW1/4 section 21, T. 35 S., R. 57 E. of the Copper River Meridian. This occurrence is close to location J006 of Wells and others (1986). The location is accurate within 1/4 mile.

Geologic setting

Geologic description The general 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). Brew and others (1978) map the country rocks at this occurrence as Permian, thin-bedded limestone and argillite, basalt and andesite, and cherty limestone and siltstone. The deposit consists of lenses and disseminations of pyrite in andesite. It is marked by iron-stained zones hundreds of feet wide and up to 1000 feet long (Brew and others, 1978). MacKevett and others (1971) report that a 6-foot chip sample contained 2 percent zinc, but Brew and others (1978) failed to find samples with elevated zinc. Still (1989), reports samples that contain anomalous gold, lead and molybdenum.
Geologic map unit	(-135.926473116149, 58.8251221467542)
Mineral deposit model	Possible metamorphosed Kuroko massive sulfide (Cox and Singer, 1986; model 28a)
Mineral deposit model number	28a
Alteration of deposit	Conspicuous iron-staining.

Production and reserves

Workings or exploration	Surface sampling only.
Indication of production	None

References

MRDS Number	A012115
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. 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. Still, J.C., 1991, Section B: Glacier Bay subarea, in U.S. Bureau of Mines, Mineral investigations in the Juneau Mining District, Alaska, 1984-1988: Volume 2 - Detailed mine, prospect, and mineral occurrence descriptions: U.S. Bureau of Mines Special Publication VOL. 2B, 69 p., 3 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