Malack

Prospect, Inactive

Commodities and mineralogy

Main commodities Cu
Ore minerals pyrite; pyrrhotite
Gangue minerals epidote; quartz

Geographic location

Quadrangle map, 1:250,000-scale SR
Quadrangle map, 1:63,360-scale B-2
Latitude 60.4236
Longitude -147.7251
Nearby scientific data Find additional scientific data near this location
Location and accuracy The prospect is located in the center of section 21, T. 4 N., R. 10 E., of the Seward Meridian. It is on the east shore of the southeast arm of Herring Bay near tidewater. This is location 202 of Cobb and Tysdal (1980), and location S-78 of Jansons and others (1984). This location is accurate to within a quarter of a mile.

Geologic setting

Geologic description

The country rock is pillow basalt altered to greenstone and is part of the Orca Group of early Tertiary age (Cobb and Tysdal, 1980). The greenstone is cut by a 3-foot-wide shear zone that trends N75W and contains as much as 50 percent epidote and 1 percent disseminated pyrrhotite. A short adit is present, and a little pyrite is visible in the dump (Tysdal, 1978 [MF-880-A]). A single chip sample of the shear zone contained 260 ppm copper (Kurtak and Jeske, 1986).
Geologic map unit (-147.727126632311, 60.4230202304075)
Mineral deposit model Cyprus massive sulfide (Cox and Singer, 1986; model 24a)
Mineral deposit model number 24a
Age of mineralization Tertiary or younger; the mineralization is in rocks of the Orca Group of Tertiary age.
Alteration of deposit There is epidote alteration of greenstone and pillow basalts (Kurtak and Jeske, 1986).

Production and reserves

Workings or exploration Tysdal (1978 [MF-880-A]) reported a short adit is present, but he gave no further details. A single chip sample of the shear zone contained 260 ppm copper (Kurtak and Jeske, 1986).
Indication of production None

References

References

Reporters Jeff A. Huber and Carol S. Huber (Anchorage)
Last report date 12/15/2000