Main commodities | Ag; Cu; Pb; Zn |
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Other commodities | Cd |
Ore minerals | chalcopyrite; galena; pyrite; sphalerite (marmatite) |
Gangue minerals | epidote; garnet; johannsenite |
Quadrangle map, 1:250,000-scale | MG |
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Quadrangle map, 1:63,360-scale | B-2 |
Latitude | 62.455 |
Longitude | -153.694 |
Nearby scientific data | Find additional scientific data near this location |
Location and accuracy | The Tin Creek-North occurrence is located near a 4,955 foot (1,510 m) summit about 6 kilometers east of Sheep Creek. The reporter visited the site in 1980. |
Geologic descriptionThe Tin Creek-North occurrence consists of thin, 5 to 20 centimeter thick mineral veins containing johansenite, garnet, sphalerite (marmatite), and chalcopyrite in argillaceous limestone of the mid-Silurian Terra Cotta Mountains Sandstone a unit of the Dillinger subterrane (Bundtzen, Harris, and Gilbert, 1997). The mineralization is hosted within a thermally altered zone where prograde garnet-johansenite veins are cut by epidote replacement bodies that are accompanied by sulfide minerals. The sulfide skarns are near a 29 Ma granodiorite dike which is part of a larger, 5 kilometer wide, N70W-trending dike swarm which intrudes the Dillinger subterrane. One grab sample contained 2.25 percent copper, 1.21 percent lead, 0.11 percent zinc, 0.13 percent cadmium, and 319.8 grams/tonne silver (Bundtzen, Kline, and Clough, 1982; Szumigala, 1987). | |
Geologic map unit | (-153.69622745481, 62.4543938181233) |
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Mineral deposit model | Copper-iron skarn (Cox and Singer, 1986; model 18b). |
Mineral deposit model number | 18b |
Age of mineralization | Inferred to be 29 Ma, based on age date from nearby granodiorite dike (Solie and others, 1991). |
Alteration of deposit | Epidotization. |
Workings or exploration | The Tin Creek-North occurrence was first described in Bundtzen, Kline, and Clough (1982). One grab sample contained 2.25 percent copper, 1.21 percent lead, 0.11 percent zinc, 0.13 percent cadmium, and 319.8 grams/tonne silver (Bundtzen, Kline, and Clough, 1982; Szumigala, 1987). |
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Indication of production | None |
Reserve estimates | None. |
Additional commentsSee MG042, Tin Creek-Midway (MG043) and Tin Creek-South (MG046) prospects. |
MRDS Number | 10307851 |
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References | |
Reporters | T.K. Bundtzen (Pacific Rim Geological Consulting) |
Last report date | 12/5/1998 |