Unnamed (west of Snowcap Mountain)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Ag; Cu; Pb; Sb; Zn
Ore minerals bornite; chalcopyrite; galena; pyrite; sphalerite

Geographic location

Quadrangle map, 1:250,000-scale LH
Quadrangle map, 1:63,360-scale B-2
Latitude 61.4644
Longitude -153.7046
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is on a glacial moraine at the head of a small east tributary to the Stony River. It is at an elevation of about 4,600 feet, 2.6 miles west-northwest of Snowcap Mountain. The map site is in the NE1/4 of section 23, T 16 N., R 25 W, of the Seward Meridian. This is locality 7 of Cobb (1972 [MF 412]; 1976 [OF 76-485]) and Cobb and Reed (1981). The location is probably accurate to within a quarter of a mile.

Geologic setting

Geologic description

Reed and Elliott (1970, p. 23) reported finding a 2-foot-diameter, float boulder of volcanic breccia containing 60 percent sulfide minerals at this locality. The boulder is in glacial float apparently derived from altered Tertiary volcanic rocks in the nearby cirque. A sample of the boulder contained 3,000 ppm silver and 1.5 percent copper, and greater than 2 percent lead, 1 percent antimony, and 1 percent zinc. Country rocks in this area are mostly Jurassic or Lower Cretaceous clastic sedimentary rocks and Upper Cretaceous or Tertiary volcanic rocks (Reed and Lanphere, 1973; Nokleberg and others, 1994).
Geologic map unit (-153.706864161832, 61.4637447563422)
Mineral deposit model Polymetallic veins? (Cox and Singer, 1986, model 22c)
Mineral deposit model number 22c?
Age of mineralization Late Cretaceous or Tertiary. The volcanic breccia is Upper Cretaceous or Tertiary.
Alteration of deposit Sulfidation.

Production and reserves

Workings or exploration Reconnaissance surface observation and sampling has been completed at this locality (Reed and Elliott, 1970).
Indication of production None

References

MRDS Number A013064

References

Nokleberg, W.J., and (seven) others, 1994, Metallogeny and major mineral deposits of Alaska and Metallogenic map of significant metalliferous lode deposits and placer districts of Alaska, in Plafker, G. and Berg, H.C., eds., The Geology of Alaska: Geological Society of America, DNAG, The Geology of North America, Vol.. G1, p. 855-904, Plate 11, scale 1:2,500,000.
Reed, B.L., and Lanphere, M.A., 1973, Alaska-Aleutian Range batholith--Geochronology, chemistry, and relation to circum-Pacific plutonism: Geological Society of America Bulletin, v. 84, no. 8, p. 2583-2610.
Reporters Travis L. Hudson and Madelyn A. Millholland
Last report date 6/10/2001