Unnamed (west side of Broxson Gulch)

Prospect, Active

Commodities and mineralogy

Main commodities Zn
Other commodities Co; Cu; Mo; Pb; Y
Ore minerals pyrite; sphalerite

Geographic location

Quadrangle map, 1:250,000-scale MH
Quadrangle map, 1:63,360-scale B-5
Latitude 63.3204
Longitude -146.1708
Nearby scientific data Find additional scientific data near this location
Location and accuracy This prospect is at an elevation of about 3,350 feet on the west side of the west fork of the stream(s) in Broxson Gulch, in the SW1/4SW1/4 section 26, T. 18 S., R. 8 E., Fairbanks Meridian. The occurrence corresponds to locality 43 in table 2 of Nokleberg and others (1991) and to locality 4 on figure 3 of Rose (1966 [ADMM GR 20]).

Geologic setting

Geologic description

The rock at this prospect is Paleozoic (?) pyritic black phyllite of the Maclaren terrane (Nokleberg and others, 1991). The deposit was described by Rose (1966 [ADMM GR 20]) as a zone of limonite-cemented talus (ferricrete?) as much as 10 feet wide next to an old pit in black 'slate'. A sample of the limonitic material contained 1,000 parts per million (ppm) zinc, 375 ppm lead, 115 ppm copper, and 12 ppm molybdenum. Nokleberg and others (1991) collected samples of pyritic limonite-cemented breccia in black phyllite at probably the same site; their samples 79IL049-051 assayed 1,800 ppm zinc, 500 ppm cobalt, and 700 ppm yttrium (table 2, locality 43). The zinc values are high enough to suggest the presence of sphalerite or an oxidized zinc mineral.
Geologic map unit (-146.173064496815, 63.3199785941855)
Mineral deposit model Unknown; the occurrence suggests a sedimentary-exhalative deposit.
Age of mineralization Unknown; possibly Paleozoic, the presumed age of the host rock.
Alteration of deposit Oxidation of iron-bearing mineral(s).

Production and reserves

Workings or exploration An old pit does not appear to have reached the black phyllite bedrock. The prospect is on active MAN Resources claims.
Indication of production None