Unnamed (north of Jack Bay)

Prospect, Inactive

Commodities and mineralogy

Main commodities Pb; Zn
Other commodities Cu
Ore minerals arsenopyrite; galena; pyrite; pyrrhotite; sphalerite
Gangue minerals calcite; quartz

Geographic location

Quadrangle map, 1:250,000-scale VA
Quadrangle map, 1:63,360-scale A-7
Latitude 61.0489
Longitude -146.5845
Nearby scientific data Find additional scientific data near this location
Location and accuracy This prospect is on the south side of the ridge between Jack Bay and Port Valdez. It is near a small cirque lake about 1,500 feet above Jack Bay at an elevation of about 1,700 feet in the NE1/4 section 35, T. 9 S., R. 8 W., of the Copper River Meridian. This prospect is probably located to within one-half mile. It is locality 37of Cobb and Matson (1972) and locality 29 of Winkler and others (1981 [OFR 80-892-B]).

Geologic setting

Geologic description

A mineralized shear zone in metagraywacke of the Valdez Group contains disseminated arsenopyrite, chalcopyrite, pyrrhotite, sphalerite, and galena (Johnson, 1919; Winkle, Miller, and others, 1981; Winkler and others, 1981 [OFR 80-892-A]). Quartz and calcite accompany the sulfide minerals in the shear zone, which is 2 to 4 feet wide, trends N 10 E, and dips 70 degrees west. A 40-foot-long adit explored this deposit. Four grab samples from the prospect area contained 10 to 190 ppm copper, 810 ppm to 0.15 percent zinc, and 0.13 to 0.18 percent lead (Jansons and others, 1984).
Geologic map unit (-146.58652533044, 61.0483707501246)
Mineral deposit model Mineralized shear zone in metaflysch
Age of mineralization Late Cretaceous or Tertiary; the mineralized shear zone cuts Upper Cretaceous rocks of the Valdez Group.
Alteration of deposit Silicification?; the sulfide minerals are accompanied by quartz and calcite.

Production and reserves

Workings or exploration This prospect was explored with a 40-foot long adit (Johnson, 1919).
Indication of production None