Quadrangle map, 1:250,000-scale | MG |
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Quadrangle map, 1:63,360-scale | A-2 |
Latitude | 62.029 |
Longitude | -153.824 |
Nearby scientific data | Find additional scientific data near this location |
Location and accuracy | This unnamed occurrence is located on a steep, southeasterly slope adjacent to the west fork of Post River at an elevation of 4,900 feet (1,494 m) in the NE1/4 sec. 3, T. 22 N., R. 25 W., of the Seward Meridian. The reporter sampled the site in 1982. |
Geologic descriptionThis unnamed occurrence is shale-hosted Ag-Cu-Zn mineralization in the Lower Ordovician-to-Lower Silurian Post River Formation, a unit of the Dillinger subterrane (Bundtzen and others, 1988). Graptolites of the Monograptus spiralis zone were found in the shale at the occurrence. A distinctive yellowish, sulfur bloom occurs in the mineralized zone, which is estimated to be about 2 meters thick. Disseminated pyrite was observed in one outcrop. Although isotopic data is lacking, Bundtzen, Harris, and Gilbert (1997) classified the occurrence as a sedimentary exhalative lead-zinc deposit. Two random chip-channel samples collected across the zone contained up to 1.37 percent zinc, 0.12 percent copper, 13.6 grams/tonne silver, and 196 ppm nickel. | |
Geologic map unit | (-153.826229188683, 62.0283717624673) |
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Mineral deposit model | Sedimentary exhalative lead-zinc? (Cox and Singer, 1986; model 31b). |
Mineral deposit model number | 31b? |
Age of mineralization | Inferred to be Lower Silurian, based on graptolite identifications (Bundtzen and others, 1988). |
Alteration of deposit | Sulfides oxidized to free sulfur. |
Workings or exploration | The reporter sampled the occurrence in 1982. Two random chip-channel samples taken across the mineralized zone contained up to 1.37 percent zinc, 0.12 percent copper, 13.6 grams/tonne silver, and 196 ppm nickel. |
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Indication of production | None |
Reserve estimates | None. |
Additional commentsSee other shale-hosted deposits in McGrath quadrangle such as MG049, MG029, MG051, MG071, MG064, and MG074. |
MRDS Number | 10307870 |
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References | |
Reporters | T.K. Bundtzen (Pacific Rim Geological Consulting) |
Last report date | 12/9/1998 |