Bear Creek (upper)

Mine, Probably inactive

Commodities and mineralogy

Main commodities Au
Other commodities Pt
Ore minerals gold; pge

Geographic location

Quadrangle map, 1:250,000-scale GO
Quadrangle map, 1:63,360-scale B-6
Latitude 59.4
Longitude -161.14
Nearby scientific data Find additional scientific data near this location
Location and accuracy Bear Creek is a south tributary of Canyon Creek. Its confluence with Canyon Creek is 3/4 mile downstream of the outlet of Canyon Lake. This placer mine is the upper of two located on Bear Creek. It is 1 3/4 miles upstream of the confluence of Bear Creek with Canyon Creek. The map site is at the junction of Bear Creek and an unnamed west tributary, in the SW1/4 of section 18, T 9 S, R 70 W, of the Seward Meridian. It is locality 17 of Hoare and Cobb (1977) and of Cobb and Condon (1972).

Geologic setting

Geologic description

Placer gold was discovered on Bear Creek as early as 1916 and mining was reported intermittently up to 1934 (Hoare and Coonrad, 1978). This site is the upper of two placer mine locations on Bear Creek shown by Cobb and Condon (1972). Harrington (1921) visited Bear Creek in 1919 and reported that initial mining had opened up a 15- by 50-foot pit, in which 2 to 3 feet of black clayey muck overlay 2 to 5 feet of gravel. The gravel was post-glacial, locally iron-stained and cemented, and mostly sedimentary material, all locally derived. Only a few very small colors were obtained in pans taken from the base of the gravels (not necessarily on bedrock). Fechner (1988) described about 1 mile of workings along this part of Bear Creek and estimated that a total of 12,000 cubic yards of material had been mined. Pay from various mine pits is reported to have run 0.002 to 0.011 ounce of gold per square foot (Reed, 1931). Fechner (1988) collected 4 samples of Bear Creek sediments; pan concentrate from these samples contained a trace to 0.624 ounce of gold per ton. A float sample of limonite-stained intrusive rock containing pyrite and arsenopyrite assayed 725 ppb gold (Fechner, 1988, sample 44). One of the sediment samples, from the main west tributary to Bear Creek (locally called Danielson Creek), yielded heavy-mineral concentrate containing more than 10 ppm platinum and anomalous As and Cu values. Minor platinum was recovered with the gold from Bear Creek and some prospecting for platinum was completed here by the Goodnews Bay Mining Company (Mertie, 1969, p. 89). An analysis of PGE material recovered from Bear Creek showed it to contain 72.82 percent platinum, 15.58 percent iridium, 8.17 percent osmium, 2.29 percent ruthenium, 0.78 percent rhodium, and 0.36 percent palladium (Mertie, 1969, Table 38). Bedrock in the area includes Paleozoic and Mesozoic sedimentary and volcanic rocks locally intruded by Upper Cretaceous to Lower Tertiary granitic rocks and Jurassic mafic/ultramafic plutonic rocks (Hoare and Coonrad, 1978).
Geologic map unit (-161.142234789768, 59.3992302393906)
Mineral deposit model Placer Au-PGE (Cox and Singer, 1986; model 39a)
Mineral deposit model number 39a
Age of mineralization Quaternary.
Alteration of deposit Iron-staining and cementation.

Production and reserves

Workings or exploration Fechner (1988) described about 1 mile of open-cut workings along this part of Bear Creek and estimated that a total of 12,000 cubic yards of material had been mined.
Indication of production Yes; small
Production notes Fechner (1988) estimated that a total of 12,000 cubic yards of material had been mined. Pay from various mine pits is reported to have run 0.002 to 0.011 ounce of gold per square foot (Reed, 1931). Production could therefore have ranged from 24 to 132 ounces of gold.

References