Mint

Mine, Inactive

Commodities and mineralogy

Main commodities Ag; Cu; Pb
Other commodities Au
Ore minerals arsenopyrite; chalcopyrite; galena; miargyrite; pyrargyrite; pyrite; tennantite
Gangue minerals quartz; sericite

Geographic location

Quadrangle map, 1:250,000-scale TK
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 setting

Geologic description

The 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)
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.

Production and reserves

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).
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 comments

MAS/MILS number 20760002.

References

MRDS Number A012201

References

Reporters R.K. Rogers (U. S. Geological Survey contractor)
Last report date 9/30/2002