Unnamed (west of upper North Fork Rainy Creek)

Occurrence, Undetermined

Commodities and mineralogy

Main commodities Ag; Au; Cu; Ni
Ore minerals chalcopyrite; pyrite; pyrrhotite

Geographic location

Quadrangle map, 1:250,000-scale MH
Quadrangle map, 1:63,360-scale B-4
Latitude 63.3201
Longitude -145.9692
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is at an elevation of about 4,950 feet on the hillside west of the middle section of the North Fork Rainy Creek. It is about 3.1 miles northwest of the junction of the North and West Forks of Rainy Creek and about 0.4 mile south of the center of section 26, T. 18 S., R. 9 E.

Geologic setting

Geologic description

This occurrence is in a unit of hornfelsed calcareous sedimentary rocks that are part of the Pennsylvanian and Permian, Slana Spur Formation, which has been intruded by Triassic gabbro dikes and sills (Rose, 1965; Nokleberg and others, 1992 [MF], 1992 [Open-File]). Bittenbender and others (2007) describe discontinuous lenses with sulfides, mainly pyrrhotite, with minor chalcopyrite and pyrite, that they traced for about 700 feet in silicified sedimentary rocks. The source of the metals may be the nearby gabbro dikes. A sample of mineralized hornfels collected by Rose (1965) contained less than 0.1 percent each of copper and nickel, 0.02 ounce of gold per ton, and 0.4 ounce of silver per ton Nokleberg and others (1991) cited a sample that contained 0.6 percent copper, 0.2 percent cobalt, 0.004 ounce of gold per ton, and 0.09 ounce of silver per ton.
Examined and sampled by the Alaskan geological survey before 1965, by the U.S. Geological Survey in before 1991, and by the Bureau of Land Management before 2007. Covered by a regionally extensive block of MAN Resources claims in 2007.
Geologic map unit (-145.971461107241, 63.3196820775521)
Mineral deposit model Weak copper-nickel mineralization in sedimentary rocks cut by gabbro dikes.
Age of mineralization Source of metals may be nearby Triassic gabbro dikes.
Alteration of deposit Scattered copper-nickel mineralization is associated with hornfelsed and silicified sedimentary rocks near gabbro dikes.

Production and reserves

Workings or exploration Examined and sampled by the Alaskan geological survey before 1965, by the U.S. Geological Survey in before 1991, and by the Bureau of Land Management before 2007. Covered by a regionally extensive block of MAN Resources claims in 2007.
Indication of production None
Reserve estimates None.
Production notes None.

References

References

Reporters W.T. Ellis (Alaska Earth Sciences), C.C. Hawley (Hawley Resource Group), and W.J. Nokleberg (USGS); D.J. Grybeck (Contractor, USGS)
Last report date 5/13/2012