East fork of Broxson Gulch

Mine, Inactive

Commodities and mineralogy

Main commodities Au
Other commodities Cu; Ni; Pb; Pt
Ore minerals galena; gold
Gangue minerals epidote; garnet; magnetite

Geographic location

Quadrangle map, 1:250,000-scale MH
Quadrangle map, 1:63,360-scale B-5
Latitude 63.326
Longitude -146.0907
Nearby scientific data Find additional scientific data near this location
Location and accuracy The locally named east fork of Broxson Gulch (see figure 2 of Rose, 1965) has been placer mined at several locations. For this record, the mine site is at an elevation of about 3,550 feet at a placer mine site reported by Rose. The mine is at the mouth of a steep-west flowing tributary to the east fork, about 1,000 feet east of the center of section 30, T. 18 S., R. 9 E., Fairbanks Meridian. The most recent place mining was about 3 miles south of the site described here, in the west bend of the east fork (W.T. Ellis, unpublished data, 1997).

Geologic setting

Geologic description

The east fork of Broxson Gulch drains fault-juxtaposed bedded rocks of the Slana Spur Formation of Late Paleozoic age and complex thrust slices of Upper Triassic ultramafic intrusive complexes (Nokleberg and others, 1991; W.T. Ellis, unpublished data, 1996). At this placer mine site near the Broxson airstrip (built since the publication of the 1978 edition of the Mount Hayes B-5 topographic map) a tributary creek drains a small fault-bounded wedge of Tertiary conglomerate (W.T. Ellis, unpublished data, 1996). This conglomerate may be the material mapped as a Quaternary fan by Stout (1976). The upper course of this tributary crosses the Airport Fault that also juxtaposes Upper Triassic ultramafic rocks and volcaniclastic strata of the Slana Spur Formation (Rose, 1965, figure 2); Nokleberg and others, 1991).
Little is known about the early placer mining here. Rose (1965, p. 35) deduced that the mine probably operated until about 1940 but that it had only small-scale activity after that. According to Rose (1965), gravel within a foot or two of the surface contained 4 to 7 colors of gold per pan; magnetite, pink garnet, and epidote occur in the concentrates. The headwaters of the tributary creek include lode mineral deposits (MH124, MH125, and MH136).
Geologic map unit (-146.092964074921, 63.3255801166143)
Mineral deposit model Placer Au-PGE (Cox and Singer, 1986, model 39a).
Mineral deposit model number 39a
Age of mineralization Holocene and Tertiary.

Production and reserves

Workings or exploration
The placer workings are mainly at the mouth of the tributary to the east fork of Broxson Gulch, just north of the airstrip (built since the publication of the 1978 edition of the Mount Hayes B-5 topographic map). Equipment is scattered around the north end of the airstrip, and there is evidence that the gravel was bulldozed and run through a wash plant and sluice. Water was brought in by more than 2 miles of ditches. The main period of operation of the mine was probably about 1940 (Rose, 1965). The most recent mining occurred 3 miles to the south, at the west bend in the east fork of the stream in Broxson Gulch (W.T. Ellis, written communication, 1997). Production from this site was reported to be small, the gold very fine, and bedrock was not reached.
The claims are now owned by MAN Resources.
Indication of production Yes; small
Production notes There has been intermittent placer mining since the early 1900s. The amount of production is uncertain but probably small.

References