Unnamed (south end of Herring Bay)

Prospect, Inactive

Commodities and mineralogy

Main commodities Cu
Other commodities Zn
Ore minerals chalcopyrite; pyrite; pyrrhotite; sphalerite
Gangue minerals epidote; quartz

Geographic location

Quadrangle map, 1:250,000-scale SR
Quadrangle map, 1:63,360-scale B-2
Latitude 60.4174
Longitude -147.7253
Nearby scientific data Find additional scientific data near this location
Location and accuracy The prospect is located in the S1/2 section 21, T. 4 N., R. 10 E., of the Seward Meridian on the southeast side of the south end of Herring Bay between sea level and 110 feet elevation. This is locations 203 and 204 of Cobb and Tysdal (1980) and location S-76 of Jansons and others (1984). This location is accurate to 300 feet.

Geologic setting

Geologic description

The prospect consists of several short adits and a prospect pit that explored thin, discontinuous sulfide veins, stringers, and lenses hosted in sheared greenstone of the Orca Group of early Tertiary age. Sulfide minerals are chalcopyrite, pyrite, pyrrhotite, and sphalerite (Cobb and Tysdal, 1980). A 50-foot adit was driven into fractured greenstone healed with quartz, pyrite, sphalerite, and chalcopyrite (Grant and Higgins, 1909). The prospect pit exposed irregular mineralization consisting of chalcopyrite, sphalerite, and pyrite. Epidote stringers occur in the country rock, but there is no well-defined vein or shear zone associated with these stringers.
Geologic map unit (-147.72732648753, 60.4168199715905)
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 Greenstone is altered to epidote.

Production and reserves

Workings or exploration Four workings are described in the literature. Grant and Higgins (1909) described a 25-foot adit that is a quarter of a mile south of the camp and a 50-foot adit. Johnson (1918 [B 662-C, p. 212]) described a 30-foot adit with a 10-foot drift to the north driven at an elevation of 110 feet. He also mentioned a 15-foot-wide open cut, west of the 30-foot adit. When the U.S. Bureau of Mines searched for this prospect in the early 1980s, they found none of these workings, and they did not collect samples from the area. Improvements on the property were two bunk and mess houses on the beach and a floating dock (Grant and Higgins, 1909). No other information is available.
Indication of production None

References

MRDS Number A010377

References

Reporters Jeff A. Huber and Carol S. Huber (Anchorage)
Last report date 3/9/2002