|Quadrangle map, 1:250,000-scale||SH|
|Quadrangle map, 1:63,360-scale||B-4|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||This occurrence is at an elevation of about 2,500 feet on an east-trending ridge, about 1.5 mile east of Billy Hawk Creek. The map site is in section 24, T. 10 N., R. 6 E., of the Kateel River Meridian. Cobb (1972, MF-448), locations 3 and 4.|
Geologic descriptionBedrock in the area of this occurrence consists of andesitic volcanic rocks of Late Jurassic-Early Cretaceous age, and quartz latite volcanic rocks of Late Cretaceous age, both of which are intruded by the Late Cretaceous Hawk River quartz monzonite. The older andesitic volcanics are thermally metamorphosed in the vicinity of the Hawk River pluton. Numerous fine-grained, pyritiferous, felsic dikes cut both the andesitic and quartz latite volcanics throughout this area. Pyrite-bearing, milky-white, vuggy, quartz veins cut the volcanics in a northwest-trending belt about 6.5 miles long by 1.5 mile wide. This belt parallels a zone of prominent, northwest-trending lineations and faults. The veins are narrow, appear to strike NE and dip steeply to the north. Locally they contain irregular segregations of argentiferous galena along with lesser chalcopyrite and malachite. Pyrite occurs in cubes up to one inch on a side and is almost completely oxidized to limonite. The galena is fresh and fills vugs and fissures along the edges of the veins. No galena or chalcopyrite were found in the volcanics, although the andesitic wallrock locally contains abundant pyrite. Grab samples contained up to 200 ppm Ag, 0.3 ppm Au, 3,000 ppm Cu, 20,000 ppm Pb, and 1,500 ppm Zn (Miller and Ferrians, 1968).
|Geologic map unit||(-157.512670176437, 66.2494161439947)|
|Mineral deposit model||Polymetallic veins (Cox and Singer, 1986; model 22c).|
|Mineral deposit model number||22c|
|Age of mineralization||Late Cretaceous or younger.|
|Alteration of deposit||Pyrite is almost completely oxidized to limonite.|
|Workings or exploration||The area was mapped by Miller and others (1966). Six rock samples and sixteen stream sediment samples were collected and analyzed by Miller and Ferrians (1968) during their field investigations. One hundred and fifty lode claims were staked in 1972 (Grybeck, 1977).|
|Indication of production||None|
Cobb, E.H., 1972, Metallic mineral resources map of the Shungnak quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-448, 1 sheet, scale 1:250,000.
Cobb, E.H., 1975, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in five quadrangles in west central Alaska (Hughes, Kotzebue, Melozitna, Selawik, Shungnak): U.S. Geological Survey Open-File Report 75-627, 58 p.
Eberlein, G.D., Chapman, R.M., Foster, H.L., and Gassaway, J.S., 1977, Map and table describing known metalliferous and selected nonmetalliferous mineral deposits in central Alaska: U.S. Geological Survey Open-File Report 77-168-D, 132 p., 1 sheet, scale 1:1,000,000.
Grybeck, Donald, 1977, Map showing known mineral deposits of the Brooks Range, Alaska: U.S. Geological Survey Open-File Report 77-166-C, 45 p., 1 sheet, scale 1:1,000,000.
Miller, T.P., and Ferrians, O.J., Jr., 1968, Suggested areas for prospecting in the central Koyukuk River region, Alaska: U.S. Geological Survey Circular 570, 12 p.
|Reporters||Anita Williams (Anchorage, AK)|
|Last report date||12/16/1999|