Main commodities | Au |
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Other commodities | Pb; Zn |
Ore minerals | arsenopyrite; galena; gold; pyrite; sphalerite |
Gangue minerals | carbonate; quartz |
Quadrangle map, 1:250,000-scale | SR |
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Quadrangle map, 1:63,360-scale | D-4 |
Latitude | 60.9453 |
Longitude | -148.3145 |
Nearby scientific data | Find additional scientific data near this location |
Location and accuracy | This prospect is located near sea level on the south shore of Bettles Bay, a northwest-trending bay in Port Wells. It is located in the NW1/4 section 24, T. 10 N., R. 6 E., of the Seward Meridian. This is location location 125 of Condon and Cass (1958), location 64 of Cobb and Richter (1972), location 83 of MacKevett and Holloway (1977), location 130 of Cobb and Tysdal (1980), and location S-157 of Jansons and others (1984). The location is accurate to within a quarter of a mile. |
Geologic descriptionThe prospect is hosted in slate and sandstone of the Valdez Group of Late Cretaceous age that is intruded by Oligocene felsic dikes (Tysdal, 1978 [MF-880-A]). The sedimentary rocks strike N48E and dip 66N. The felsic dike is 18 inches wide, strikes N43E, and dips vertically. The deposit consists of two intersecting quartz-carbonate veins that, at the portal, respectively strike N15W and N20W and dip 72W and 86W. The veins merge underground and continue along a 4-foot-wide, N20W shear zone. The veins are banded with quartz and carbonate that carries arsenopyrite, galena, sphalerite, and gold (Johnson 1914 [B 592-G, p. 232]). The U.S. Bureau of Mines assayed five samples from the workings; they contained a trace to 0.77 ounce of gold per ton and a trace to 0.41 ounce of silver per ton (Jansons and others, 1984). | |
Geologic map unit | (-148.316587146808, 60.9447213317624) |
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Mineral deposit model | Low-sulfide Au-quartz veins (Cox and Singer, 1986; model 36a) |
Mineral deposit model number | 36a |
Age of mineralization | Oligocene or younger; quartz veins cut an Oligocene dike. |
Workings or exploration |
Workings consists of a single 45-foot adit with a 40-foot-deep winze and some stripping (Johnson, 1914 [B 592-G, p. 232]). A rotten log structure is located immediately above the portal (Hoekzema and Sherman, 1983). Jansons and others (1984) assayed five samples; these contained a trace to 0.77 ounce of gold per ton and a trace to 0.41 ounce of silver per ton. They described the workings as very hazardous and did not attempt to map them. |
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Indication of production | None |
Reserve estimates | The U.S. Bureau of Mines estimates a resource of 500 tons of ore grading 0.3 ounce of gold per ton and 0.24 ounce of silver per ton (Hoekzema and Sherman, 1983). |
Additional commentsU.S. Bureau of Mines reports a 47-foot adit with a 20- to 30-foot winze (Jansons and others, 1984). This differs from Johnson's (1914 [B 592-G, p. 232]) description of the workings. |
MRDS Number | A010389 |
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ReferencesHoekzema, R.P., and Sherman, G.E., 1983, Mineral investigations in the Chugach National Forest, Alaska (Peninsula study area): U.S. Bureau of Mines in-house report; held at U.S. Bureau of Land Management Alaska State Office, Anchorage, 524 p.
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Reporters | Jeff A. Huber (Anchorage) |
Last report date | 3/7/2000 |