Unnamed (Surprise Cove)

Prospect, Inactive

Commodities and mineralogy

Main commodities Ag
Other commodities Au; Cu; Pb; Zn
Ore minerals chalcopyrite; galena; pyrite; pyrrhotite; sphalerite
Gangue minerals calcite; chlorite; quartz

Geographic location

Quadrangle map, 1:250,000-scale SR
Quadrangle map, 1:63,360-scale C-4
Latitude 60.7382
Longitude -148.3733
Nearby scientific data Find additional scientific data near this location
Location and accuracy The prospect is situated on the northwest side of Cochrane Bay about a mile south of Surprise Cove. It is in the SE1/4 section 34, T. 8 N., R. 6 E., of the Seward Meridian. This is location S-104 of Jansons and others (1984). This location is accurate to within a quarter of a mile.

Geologic setting

Geologic description

The prospect consists of a 3- to 15-foot-wide shear zone that is exposed along strike for as much as 1,000 feet. The shear zone contains several quartz and quartz-calcite-chlorite veins (Jansons and others, 1984). The bedrock in this area is mapped as shale and graywacke of the Upper Cretaceous Valdez Group (Tysdal and Case, 1979). The veins and sheared sedimentary rocks contain both disseminations and podiform masses of chalcopyrite, galena, pyrite, pyrrhotite, and sphalerite. Overall, the shear zone contains 1 percent sulfides (Jansons and others, 1984).
Samples collected by the U.S. Bureau of Mines include an 8-inch chip sample containing 130 ppm silver and float rock samples containing 4.25 percent copper, 3.5 percent arsenic, and 0.3 percent zinc (Jansons and others, 1984).
Geologic map unit (-148.375384342977, 60.7375936733785)
Mineral deposit model Low-sulfide Au-quartz veins (Cox and Singer, 1986; model 36a)
Mineral deposit model number 36a
Age of mineralization Cretaceous or younger; the deposit is in a shear zone that cuts rocks Valdez Group rocks of Late Cretaceous age.

Production and reserves

Workings or exploration Samples collected by the U.S. Bureau of Mines include an 8-inch chip sample containing 130 ppm silver, and float rock samples containing 4.25 percent copper, 3.5 percent arsenic, and 0.3 percent zinc (Jansons and others, 1984).
Indication of production None

References