East Broxson Gold

Prospect, Active?

Commodities and mineralogy

Main commodities Au; Cu; Pd; Pt
Ore minerals chalcopyrite; gold; pyrrhotite

Geographic location

Quadrangle map, 1:250,000-scale MH
Quadrangle map, 1:63,360-scale B-5
Latitude 63.3471
Longitude -146.0033
Nearby scientific data Find additional scientific data near this location
Location and accuracy The East Broxton Gold prospect is at an elevation of about 4,400 feet in the headwaters of east fork of Broxson Gulch near the terminus of two unnamed glaciers. It is about 0.8 mile northwest of elevation 6045 and about 0.5 mile north of the center of section 22, T. 18 S., R. 9 E.

Geologic setting

Geologic description

The East Broxson Gold prospect is in the Late Triassic Rainey ultramafic-mafic complex that intrudes the Slana Spur Formation of Pennsylvanian and Permian age. The Rainy complex is up to 5,000 feet thick, dips shallowly north and is mainly serpentinized dunite with subordinate peridotite, pyroxenite, and gabbro (Nokleberg and others, 1992 [Open-File]; Nokleberg and others, 1992 [MF]; Bittenbender and others, 2007). In this area, the base of the complex is a layered gabbro as much as 1,500 feet thick.
From 1995 to 1999, the prospect was explored by American Copper and Nickel Company (ACNC) working with Fort Knox Gold Resources, Inc. in their regional search for copper-nickel-PGE mineralization. Their work in the area included rock sampling, and airborne and ground geophysical surveys W.T. Ellis, oral communication, 2001). Claims held by MAN Resources were active through at least 2001 (W.T. Ellis, personal communication, 2001).
The mineralization consists of disseminated pyrrhotite and pentlandite in a peridotite near the northern contact of the Rainy complex (W.T. Ellis, oral communication, 2001). A mineralized sample contained 0.05 percent nickel, 0.58 percent copper, 1,950 parts per billion (ppb) gold, 36 ppb palladium, and 140 ppb platinum. (W.T. Ellis, oral communication, 2001). Bittenbender and others (2007) searched the area but could not find mineralized rock. They collected three samples but none had base or precious metals significantly above background.
Geologic map unit (-146.005564742004, 63.3466822941214)
Mineral deposit model Gold-nickel-copper-PGE mineralization in a differentiated mafic-ultramafic complex.
Age of mineralization Genetically related to the emplacement of a Late Triassic mafic-ultramafic complex.

Production and reserves

Workings or exploration From 1995 to 1999, the prospect was explored by American Copper and Nickel Company (ACNC) working with Fort Knox Gold Resources, Inc. in their regional search for copper-nickel-PGE mineralization. Their work in the area included rock sampling, and airborne and ground geophysical surveys W.T. Ellis, oral communication, 2001). Claims held by MAN Resources were active through at least 2001 (W.T. Ellis, personal communication, 2001). Examined and sampled by the Bureau of Land Management in the early 2000s.
Indication of production None
Reserve estimates None.
Production notes None.

References