Brown Bear (ARDF #KD029) Ag, Au

Brown Bear

Prospect, Inactive

Alternative names

Old Harbor
Silver Queen
Barling Bay

Commodities and mineralogy

Main commodities	Ag; Au
Ore minerals	arsenopyrite; gold; pyrite; pyrrhotite; sparse tetrahedrite
Gangue minerals	chlorite; quartz; sericite

Geographic location

Quadrangle map, 1:250,000-scale	KD
Quadrangle map, 1:63,360-scale	A-5
Latitude	57.212
Longitude	-153.386
Nearby scientific data	Find additional scientific data near this location
Location and accuracy	This prospect is located 0.3 mile north of triangulation station Love at the head of Barling Bay (Berg and Cobb, 1967, figure 15, locality 13; Cobb, 1972, MF 460, locality 5; McGee, 1972, locality 1; MacKevett and Holloway, 1977, locality 5) Site location is accurate to within 1/4 mile.

Geologic setting

Geologic description Three separate sulfide-bearing quartz veins, the Brown Bear, Old Harbor, and Silver Queen, cut Cretaceous metasedimentary rock. The Brown Bear vein, said to have been traced for several miles, strikes northeast, generally parallel to bedding. The dip is irregular and varies from 90 to 15 southeast. At one point the vein has a thickness of 15 feet. At another the vein splits into 3 bands 18 inches, 30 inches, and 6 feet in thickness. Assays of nine samples taken by Roehm (1936, PE 131-5) on the Brown Bear vein ranged from trace gold, trace silver over 32 inches to 0.58 ounce per ton gold and 0.30 ounce per ton silver over 12 inches. A basic dike, an aplite dike, and a porphyry dike crop out in the vicinity of the vein. The Old Harbor vein crops out approximately 400 feet above the Brown Bear. It averages 5 feet in thickness and is said to have been traced for 3000 feet. No descriptions of the Silver Queen vein are available.
Geologic map unit	(-153.388254517603, 57.2112171114576)
Mineral deposit model	Chugach-type low-sulfide gold-quartz vein (Bliss, 1992; model 36a.1), turbidite-hosted gold vein.
Mineral deposit model number	36a.1
Age of mineralization	Cretaceous or younger

Production and reserves

Workings or exploration	The Brown Bear vein in 1936 had been developed by a 42-foot adit, a 23-foot adit and several open cuts. Open cuts and pits exposed some of the other veins. Nine samples taken by Roehm (1936, PE 131-5) on the Brown Bear vein assayed from trace gold and silver over 32 inches to 0.58 ounce per ton gold and 0.30 ounce per ton silver over 12 inches.
Indication of production	Undetermined
Additional comments Most of the area is on land conveyed to the Koniag Corporation.

References

MRDS Number	A015092
References Berg, H.C., and Cobb, E.H., 1967, Metalliferous lode deposits of Alaska: U.S. Geological Survey Bulletin 1246, 254 p. Capps, S.R., 1937, Kodiak and adjacent islands, in Smith, P.S. and others, Mineral resources of Alaska, report on progress of investiagtions in 1935: U.S. Geological Survey Bulletin 880-C, p. 111-184, 1 plate, scale 1:250,000. Cobb, E.H., 1972, Metallic mineral resources map of the Kodiak quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-460, 1 map sheet, scale 1:250,000. Cobb, E.H., 1979, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Afognak, Karluk, Kodiak, and Trinity Islands quadrangles, Alaska: U.S. Geological Survey Open-File Report 79-860, 49 p. MacKevett, E.M., Jr., and Holloway, C.D., 1977, Map showing metalliferous mineral deposits in the western part of southern Alaska: U.S. Geological Survey Open-File Report 77-169-F, 38 p., 1 sheet, scale 1:1,000,000. McGee, D.L., 1972, Kodiak Island and vicinity, Alaska: Geology and mineral resources: Alaska Division of Geological & Geophysical Surveys Alaska Open-File Report 31, 7 p., 1 sheet, scale 1:250,000. Roehm, J.C., 1936, Preliminary report of Brown Bear Group, Kodiak mining district, Kodiak Island, Alaska: Alaska Territorial Department of Mines Prospect Evaluation 131-5, 4 p. (1 sheet, scale 1 inch=300 feet, 2 sheets, scale 1 inch=20 feet).
Reporters	S.H. Pilcher (Anchorage)
Last report date	10/12/1998