Main commodities | Ag; Cu; Pb |
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Other commodities | Au |
Ore minerals | arsenopyrite; chalcopyrite; galena; miargyrite; pyrargyrite; pyrite; tennantite |
Gangue minerals | quartz; sericite |
Quadrangle map, 1:250,000-scale | TK |
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Quadrangle map, 1:63,360-scale | D-5 |
Latitude | 62.8586 |
Longitude | -149.3669 |
Nearby scientific data | Find additional scientific data near this location |
Location and accuracy | The Mint Mine is located on the west side of Portage Creek, about 2.8 miles north of its mouth on the Susitna River. The mine workings extend from the creek for about 230 feet above it. The mine is in the SE1/4 sec. 13, T. 32 N., R. 1 W., Seward Meridian. The location is accurate to within 1/4 mile. The property was also called the Portage Creek mine. The Cheechako Moose 1-5 and 7-30 claims were staked here. |
Geologic descriptionThe rocks at the Mint mine are blocky slate that strikes North to N30E and dips 20-80W (Richter, 1963; Kurtak and others, 1992). The slate is cut by a 5- to 12-foot-thick andesite dike that strikes N20W and dips 75SW. The dike contains sericitized orthoclase phenocrysts in a groundmass of altered feldspar laths. The dike and country rocks are cut by quartz veinlets containing small amounts of pyrargyrite, miargyrite, arsenopyrite, chalcopyrite, galena, tennantite, and pyrite (Richter, 1963). The working consist of adits 15 feet, 17 feet, and 240 feet long. and an open cut . Rock samples contain up to 7.8 ounces of silver per ton, and 3 parts per million gold (Kurtak and others, 1992). A 40-pound sample selected in 1926 contains 117.9 ounces of silver per ton (Capps and Short, 1926). No details are available but Capps and Short (1926) indicate that a small amount of ore was shipped. | |
Geologic map unit | (-149.369163699362, 62.8581177717551) |
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Mineral deposit model | Polymetallic vein? (Cox and Singer, 1986; model 22c?) |
Mineral deposit model number | 22c? |
Alteration of deposit | An altered andesitic dike contains sericitized orthoclase phenocrysts in a groundmass of altered plagioclase. |
Workings or exploration | The working consist of adits 15 feet, 17 feet, and 240 feet long and an open cut . Rock samples contain up to 7.8 ounces of silver per ton, and 3 parts per million gold (Kurtak and others, 1992). A 40-pound sample selected in 1926 contains 117.9 ounces of silver per ton (Capps and Short, 1926). |
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Indication of production | Yes; small |
Production notes | No details are available but Capps and Short (1926) indicate that a small amount of ore was shipped. |
Additional commentsMAS/MILS number 20760002. |
MRDS Number | A012201 |
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References | |
Reporters | R.K. Rogers (U. S. Geological Survey contractor) |
Last report date | 9/30/2002 |