Unnamed (south-flowing tributary to Coal Creek)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Au
Other commodities Hg
Ore minerals arsenopyrite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale MH
Quadrangle map, 1:63,360-scale A-6
Latitude 63.1895
Longitude -146.9248
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is at an elevation of about 4,800 feet at the head of an unnamed south-flowing tributary to Coal Creek, in the S1/2SW1/4 section 11, T. 20 S., R. 4 E., Fairbanks Meridian. The location corresponds to mineral occurrence 27 of Clautice and others (1988, 1989). The location is accurate within one-tenth of a mile.

Geologic setting

Geologic description

A small, probably Cretaceous granodiorite plug and felsite dikes intrude greenstone and argillite in the area of this occurrence (Kaufman, 1964). The deposit consists of an iron-stained quartz stockwork in argillite (Clautice and others, 1989, plate 2). The stockwork is strongly anomalous in arsenic (1,925 parts per million [ppm]) and mercury (64 ppm) and contains 170 parts per billion (ppb) gold (Clautice and others, 1988, sample 33882). Stream-sediment sample 33610S collected about one-half mile downstream was anomalous in arsenic (495 ppm) and somewhat anomalous in tungsten (25 ppm).
Geologic map unit (-146.927064586779, 63.1890576475622)
Mineral deposit model Low-sulfide Au-quartz veins (Cox and Singer, 1986, model 36a).
Mineral deposit model number 36a
Age of mineralization Probably Cretaceous, related to intrusion of granodiorite and felsite dikes.

Production and reserves

Workings or exploration There are no workings at the site.
Indication of production None

Additional comments

An arsenic anomaly at the mouth of the tributary stream suggests further prospecting is warranted in the area.