Lucky Bear

Occurrence, Inactive

Commodities and mineralogy

Main commodities Ag; Au; Cu; Mo; Pb; Zn
Other commodities Ba
Ore minerals galena; molybdenite; pyrite; pyrrhotite; sphalerite

Geographic location

Quadrangle map, 1:250,000-scale TY
Quadrangle map, 1:63,360-scale C-5
Latitude 61.6812
Longitude -151.7752
Nearby scientific data Find additional scientific data near this location
Location and accuracy Lucky Bear is located about 4.2 miles southeast of Hayes River Pass; about 0.5 mile west-northwest of the center of section 2, T. 18 N., R. 14 W., of the Seward Meridian. The location is accurate to within about 500 feet from the center of the occurrence (Ellis, 1994).

Geologic setting

Geologic description

Lucky Bear is an occurrence in the Beluga Project Area. This area is made of Cretaceous sedimentary units that have been intruded by 62 Ma felsic hypabyssal rocks and exhibits porphyry style alteration and lead-zinc-silver mineralization. Numerous color anomalies were noted in the lower parts of the stream valleys within the felsic package and massive sulfide float boulders were also discovered (Ellis, 1994). The Cook Inlet region geologic map (Wilson and others, 2012) shows that this occurrence occurs in an area of intermediate composition Cretacous volcanic and sedimentary rocks.
This area has been intruded by younger 62 million year old felsic intrusive volcanic and sedimentary packages that exhibit porphyry style alteration and lead-zinc-silver mineralization. Lucky Bear is characterized by veins and breccias with sphalerite and galena and stratiform massive sulfide pods and lenses of pyrrhotite and sphalerite up to 2 feet thick and 20 feet long. They are intermittently exposed within a 1 to 200 foot thick interval of thin-bedded siltstone, fine-grained tuff and chert. Mineralization can be traced a few thousand feet along strike. Quartz-calcite gangue is locally recrystallized and epidote-altered. Mineralization is either exhalative volcanic massive sulfides (VMS) or replacement (Ellis, 1994).
Geologic map unit (, )
Mineral deposit model Kuroko massive sulfide (Cox and Singer, 1986; model 28a).
Mineral deposit model number 28a
Age of mineralization A fine-grained porphyry returned an age of 62 million years using argon-argon dating analyzed by the University of British Columbia petrology lab (Ellis, 1994).
Alteration of deposit Quartz-calcite gangue is locally recrystallized and epidote-altered (Ellis, 1994).

Production and reserves

Workings or exploration
In 1993, a reconnaissance effort was carried out by American Copper and Nickel Company's 'Alaska Task Force' to identify targets for future work (Ellis, 1994).
Exploration by American Copper and Nickel Company in 1994 focused on mapping, sampling and prospecting. Twenty rock samples and five stream and pan samples from Lucky Bear were collected and analyzed. Average results were 470 parts per billion (ppb) gold, 3 parts per million (ppm) silver, 0.2 percent copper, 8.6 percent zinc (Ellis, 1994).
Indication of production None

References

References

Reporters V.C. Zinno (Alaska Earth Sciences, Inc.)
Last report date 3/15/2016