1. Mineral Resources
  2. Online Spatial Data
  3. Alaska Resource Data File (ARDF)

Tin Creek-North

Occurrence, Inactive

Map
KML
XML
GeoJSON

Commodities and mineralogy

Main commodities Ag; Cu; Pb; Zn
Other commodities Cd
Ore minerals chalcopyrite; galena; pyrite; sphalerite (marmatite)
Gangue minerals epidote; garnet; johannsenite

Geographic location

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

Geologic description

The 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)
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.

Production and reserves

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).
Indication of production None
Reserve estimates None.

Additional comments

See MG042, Tin Creek-Midway (MG043) and Tin Creek-South (MG046) prospects.

References

MRDS Number 10307851

References

Bundtzen, T.K., Harris, E.E., and Gilbert, W.G., 1997, Geologic Map of the eastern McGrath quadrangle, Alaska: Alaska Division of Geological and Geophysical Surveys Report of Investigations 97-14, 34 p., 1 sheet, scale 1:125,000.
Bundtzen, T.K., Kline, J.T., and Clough, J.G., 1982, Preliminary geologiy of the McGrath B-2 quadrangle, Alaska: Alaska Division of Geological and Geophysical Surveys Open-File report 149, 22 p., 1 sheet, scale 1:40,000.
Szumigala, D.J., 1987, Geology of the lead-zinc skarn deposits at Tin Creek area, McGrath B-2 quadrangle, Alaska: Alaska Division of Geological and Geophysical Surveys Report of Investigations 87-5, 21 p., 1 sheet, 1:10,000 scale.
Reporters T.K. Bundtzen (Pacific Rim Geological Consulting)
Last report date 12/5/1998