Main commodities | Ag; Au |
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Other commodities | Cu; Pb; Zn |
Ore minerals | arsenopyrite; chalcopyrite; galena; gold; pyrite; sphalerite |
Gangue minerals | quartz |
Quadrangle map, 1:250,000-scale | SV |
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Quadrangle map, 1:63,360-scale | C-2 |
Latitude | 59.574 |
Longitude | -150.508 |
Nearby scientific data | Find additional scientific data near this location |
Location and accuracy | These prospects are located just south of Pilot Harbor on the west side of the North Arm of Nuka Bay. The Hatcher prospect consists of two short adits near the high tide line, just south of the entrance to Pilot Harbor. The Utopia and North Gold claims are described as being about one mile south of Pilot Harbor and the workings consist of a series of short tunnels and prospect pits which trace multiple white quartz veins up the ridge. This is Cobb's (1972, MF-397) location 24 and Richter's (1970) location 7. Cobb (1979, OFR 80-87) summarized the relevant references to this prospect under the name Hatcher. The location of the two adits is accurate to within 300 feet. |
Geologic descriptionThe host rock of the prospects is Cretaceous Valdez Group slates and graywackes (Richter, 1970). The quartz veins are typical of the district and consist of white crystalline quartz with varying amounts of sulfides. Arsenopyrite is the dominate sulfide with decreasing amounts of pyrite, chalcopyrite, sphalerite, and galena. Gold occurs as free gold and is associated with arsenopyrite. The veins are confined to the more massive graywacke units and commonly pinch out when they splay into the slate units. The veins at the various tunnels and prospect pits range in width from five inches to over five feet. The general strike of the veins is east-west with a near vertical dip. | |
Geologic map unit | (-150.510104306737, 59.5734197654941) |
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Mineral deposit model | Low-sulfide, Au-quartz vein (Cox and Singer, 1986; model 36a) |
Mineral deposit model number | 36a |
Age of mineralization | Tertiary; Boden and others (1991) report other veins in the district are about 55 m.y. old. |
Alteration of deposit | Borden and others (1991) report carbonization, sulfidization, sericitization, and silicification of the wall rock adjacent to the veins. |
Workings or exploration | The workings consist of several short tunnels and numerous prospect pits. No assay results are reported. |
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Indication of production | None |
Reserve estimates | None. |
Additional commentsThese prospects are within Kenai Fjords National Park; the area is closed to mineral entry. |
MRDS Number | A010577 |
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ReferencesPilgrim, E.R., 1933, Nuka Bay district, in Stewart, B. D., Making mining investigations and mine inspection in Alaska, biennium ending March 31, 1933: Alaska Territorial Department of Mines Annual Report 1933B, p. 26-51.
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Reporters | Jeff A. Huber (Anchorage) |
Last report date | 2/9/1999 |