| Quadrangle map, 1:250,000-scale | WI |
|---|---|
| Quadrangle map, 1:63,360-scale | C-4 |
| Latitude | 67.5217 |
| Longitude | -151.5889 |
| Nearby scientific data | Find additional scientific data near this location |
| Location and accuracy | This occurrence is located on a ridge between Sirr Creek and Wild Lake, about 1.6 miles north of the mouth of Seward Creek on Wild Lake. It is about 0.4 mile south-southwest of the center of section 9, T. 31 N,, R. 18 W. The occurrence is the site of sample 128 of Chipp (1972). Several other samples were collected for about 1.5 miles up the ridge to the north by Chipp (1972), and Kurtak and others (2002) The location is accurate. |
Geologic descriptionThis occurrence consists of numerous thin quartz veins and lenses in Middle to Lower Devonian chlorite and sericite schist (Dillon and others, 1986). Most are barren quartz although some also contain ankerite(?). Over an area about 200 by 300 feet in size, small amounts of tetrahedrite(?), chalcopyrite, galena, malachite, and pyrite are scattered through the quartz (Chipp, 1972; Kurtak and others, 2002). One sample of altered calcareous schist with vein quartz and unspecified sulfides contains 0.52 parts per million (ppm) gold, 31 ppm silver, 1 percent antimony, 9,700 ppm copper, 2,400 ppm lead, and 1,000 ppm zinc (Chipp, 1972; sample 128). | |
| Geologic map unit | (-151.591654214304, 67.5212485656802) |
|---|---|
| Mineral deposit model | Scattered, thin quartz lenses and veins with rare, scattered base and precious-metal minerals. |
| Age of mineralization | Unclear other than the veins and lenses are probably younger than the Devonian host rocks. |
| Alteration of deposit | Chipp (1972) and Dillon and others (1981) describe some of the samples as altered calcareous-schist, but did not describe the alteration. |
| Workings or exploration | Briefly examined and sampled by the Alaska Division of Geological and Geophysical Surveys (Chip, 1972, Dillon and others, 1981) and the Bureau of Land Management (Kurtak and others, 2002). |
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| Indication of production | None |
| Reserve estimates | None. |
| Production notes | None. |
| MRDS Number | A011935 |
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ReferencesKurtak, J.M., Klieforth, R.F., Clark, J.M., and Maclean, E.A., 2002, Mineral investigations in the Koyukuk mining district, northern Alaska: Final Report: U.S. Bureau of Land Management Technical Report 50, 2 vols., 845 p.
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| Reporters | J.M. Britton (Anchorage); D.J. Grybeck (Contractor, USGS) |
| Last report date | 2/1/2011 |