Unnamed (on Bear Creek)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Au; Cu; Pb; Zn
Ore minerals bournonite; galena; gold; pyrite; sphalerite
Gangue minerals calcite; limonite; quartz

Geographic location

Quadrangle map, 1:250,000-scale CA
Quadrangle map, 1:63,360-scale C-5
Latitude 65.54
Longitude -161.06
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is on Bear Creek, about a half-mile above the junction of Bob Creek. The map site is 200 feet north of the north end of the airstrip, in section 25, T. 2 N., R. 12 W., of the Kateel River Meridian. Cobb (1972, MF-389), location 15.

Geologic setting

Geologic description

Miller and Elliott (1969) report that galena, sphalerite and pyrite occur in andesite at the north end of the airstrip on Bear Creek. The sulfides occur in quartz-calcite veinlets and as disseminated grains in the andesite near a mafic syenite dike. The mineralized zone is about 200 feet wide and trends northwest. Gold can be panned from the limonite cap over the mineralized rock. Stream-sediment samples downstream from the mineralized zone indicate a lead-zinc-copper anomaly extending for about a mile. Soil samples from a drainage ditch above the deposit contain anomalous lead and zinc. Placer gold has been intermittently mined on Bear Creek, mostly downstream from the mineralized area. A polished section shows that arsenopyrite, bournonite and a little gold are present in the sulfide aggregate. This occurrence occurs entirely in Jurassic-Cretaceous andesite and has anomalously high values of antimony and gold.
Seven rock samples were collected and analyzed by Miller and Elliot (1969). Gold values were all anomalous and varied from 0.4 to 3.0 ppm; silver varied from 1.5 to 150 ppm; arsenic varied from 500 to greater than 10,000 ppm; copper ranged from 50 to 1,000 ppm; lead ranged from 200 to greater than 20,000 ppm; and zinc varied from 700 to greater than 10,000 ppm.
Geologic map unit (-161.062655745548, 65.5393313203667)
Mineral deposit model Sulfides in altered andesite.
Age of mineralization Jurassic - Cretaceous or younger.
Alteration of deposit Limonite alteration.

Production and reserves

Workings or exploration The site has been visited and sampled by U.S. Geological Survey and ADGGS geologists. Several exploration companies have also visited the occurrence.
Indication of production None

Additional comments

Not well enough exposed to evaluate potential of deposit.


MRDS Number A013493


Smith, S.S., 1917, The mining industry in the Territory of Alaska during the calendar year 1915: U.S. Bureau of Mines Bulletin 142, 65 p.
Reporters Anita Williams (Anchorage, AK)
Last report date 1/12/2000