Red Mountain

Prospect, Active

Commodities and mineralogy

Main commodities Pt
Ore minerals platinum group metal alloys

Geographic location

Quadrangle map, 1:250,000-scale HG
Quadrangle map, 1:63,360-scale D-6
Latitude 58.93
Longitude -161.77
Nearby scientific data Find additional scientific data near this location
Location and accuracy This prospect represents the deeper, subsurface part of the Red Mountain ultramafic pluton. The surface coordinate location (map site) above this prospect is on the southern end of the pluton above and west of the headwaters of Fox Gulch. It is at an elevation of 1,000 to 1,250 feet and very approximately located.

Geologic setting

Geologic description

This prospect represents the deeper, subsurface part of the Red Mountain ultramafic pluton. This large Jurassic pluton is mostly dunite, but the eastern border zone includes bands of peridotite, clinopyroxenite, and hornblende-bearing rocks that are zoned outward from dunite in that order. Gravity and aeromagnetic surveys over the Red Mountain pluton show that it is thicker and more deeply seated in its southern part (Alaska Earth Sciences, 2000). This relationship has led to the interpretation that the ultramafic magma was emplaced through a deep feeder conduit in this area. A conceptual diagram of this prospect infers a sulfide-rich, PGM-bearing cumulate zone along the footwall of the feeder conduit (Alaska Earth Sciences, 2000).
Geologic map unit (-161.772234093088, 58.9292164904641)
Mineral deposit model Alaskan PGE (Cox and Singer, 1986; model 9).
Mineral deposit model number 9
Age of mineralization Jurassic, the age of the Red Mountain ultramafic pluton. Hoare and Coonrad (1978) report K/Ar ages for two samples of amphibole from the southeast border of the Red Mountain pluton: 176.4 +/- 5.3 Ma and 186.9 +/- 5.6 Ma.

Production and reserves

Workings or exploration An aeromagnetic survey was flown over the Salmon River (Goodnews) area in 1994, a gravity survey has been completed, and some controlled-source audio magneto-telluric lines have been run over selected parts of the ultramafic complex (Alaska Earth Sciences, 2000).
Indication of production None


MRDS Number 10307612


Alaska Earth Sciences, 2000, The Goodnews Bay ultramafic complexes: Unpublished data,
Reporters Travis L. Hudson
Last report date 3/18/2001