Pass

Prospect, Inactive

Commodities and mineralogy

Main commodities Cu; Pb
Other commodities Ag; Mo; Sb; Zn
Ore minerals argentiferous tetrahedrite; chalcopyrite; galena; molybdenite; pyrite; pyrrhotite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale LC
Quadrangle map, 1:63,360-scale B-4
Latitude 60.38
Longitude -154.47
Nearby scientific data Find additional scientific data near this location
Location and accuracy About 10.8 km NW of Kijik Lake. Locality 16 of Nelson and others (1985) and locality 24 of MacKevett and Holloway (1977). Sec. 3, T. 3 N., R. 30 W., of the Seward Meridian. Locality is accurate to within 2.0 km.

Geologic setting

Geologic description

Iron-staining reported to be related to stockwork-fracture filling of pyrite and (or) pyrrhotite and varying amounts of chalcopyrite, galena, and tetrahedrite (?). Resource Associates of Alaska (1976) reported values up to 470 ppm Ag, 3,000 ppm Cu, 1,500 ppm Pb, and 3,600 ppm Zn. Mineralization is associated with a silicified, brecciated zone in propylitically altered dacite porphyry, possibly an explosive vent breccia, part of unit Tv (Nelson and others, 1983). Unit Tv includes rhyolitic breccia, ash-flow tuff, flows, and intrusive rocks and subordinate mafic to intermediate flows. Potassium-argon ages for Unit Tv range from 56.2 to 62.7 m.y. indicating a Tertiary age for these rocks (Eakins and others, 1978).
Geologic map unit (-154.472226958731, 60.3793297081136)
Mineral deposit model Porphyry Cu-Mo? (Cox and Singer, 1986; model 21a?).
Mineral deposit model number 21a?
Age of mineralization Tertiary; potassium-argon ages for rocks of Unit Tv range from 56.2 to 62.7 m.y. (Eakins and others, 1978).
Alteration of deposit Iron-staining, silicification, and propylization of the dacite.

Production and reserves

Workings or exploration Resource Associates of Alaska (1976) reported values up to 470 ppm Ag, 3000 ppm Cu, 1500 ppm Pb, and 3600 ppm Zn. Eakins and others (1978) reported a Mo anomaly of 66 ppm.
Indication of production None
Reserve estimates No reserves
Production notes No production

Additional comments

No ore grade mineralization has been discovered (Nelson and others, 1985). Site is in Lake Clark National Park and Preserve.

References

MRDS Number A013010

References

Resource Associates of Alaska, Inc., 1976, Geology and geochemistry of certain land within the Lake Clark National Park: Contract report for U.S. Bureau of Mines, Contract JO166108, 7 v.
Young, L.E., St. George, P., and Bouley, B., 1997, Porphyry copper deposits in relation to the magmatic history and palinspastic restoration of Alaska, in Goldfarb, R.J., and Miller, L.D., eds., Mineral deposits of Alaska: Economic Geology Monograph 9, p. 306-333.
Reporters M.L. Miller (USGS); D.P. Bickerstaff (USGS)
Last report date 6/15/1998