Lone Mountain

Occurrence, Inactive

Commodities and mineralogy

Main commodities Cu
Other commodities Ag; Au; W
Ore minerals pyrite
Gangue minerals carbonate; quartz

Geographic location

Quadrangle map, 1:250,000-scale GO
Quadrangle map, 1:63,360-scale B-4
Latitude 59.36
Longitude -160.23
Nearby scientific data Find additional scientific data near this location
Location and accuracy Lone Mountain is an upland between Gechiak Creek and another (unnamed) west tributary to the Togiak River. This occurrence is assumed to be on the east side of Lone Mountain, in the larger drainage that flows east to Togiak River. For this record, the map site is at an elevation of 1,300 feet on the north flank of Lone Mountain, in the SE1/4 of section 28, T 9 S, R 65 W, of the Seward Meridian. This occurrence is area 2 of Kilburn and others (1992). It is approximately located, perhaps within a mile.

Geologic setting

Geologic description

Lone Mountain is centered on a Cretaceous or Tertiary felsic stock surrounded by hornfels (Hoare and Coonrad, 1978). The iron-stained hornfels, which is locally gossan, contains disseminated pyrite and small quartz-pyrite veinlets. Quartz veinlets are also locally present in iron-stained parts of the stock near the contact zone. Stream-sediment samples from the area contain anomalous amounts of As, Bi, Cu, Pb, Mo, W, or Zn (Cieutat and others, 1988; Hessin and others, 1978 [OF 78-9-Q; OF 78-9-M]). Hornfels and veinlet samples collected near the eastern contact mostly contain anomalous amounts of copper (up to 900 ppm Cu) and up to 1.2 ppm Ag, 0.01 ppm Au, 26 ppm Bi, 7.2 ppm Mo, 30 ppm Sn, and 50 ppm W (Kilburn and others, 1992). One iron-stained, carbonate-cemented breccia contained 460 ppm As, 0.15 ppm Au, 1.9 ppm Hg, and 11 ppm Sb.
Geologic map unit (-160.232220209443, 59.359238816826)
Mineral deposit model Polymetallic veins (Cox and Singer, 1986; model 22c)
Mineral deposit model number 22c
Age of mineralization Probably Late Cretaceous or Early Tertiary. Mineralization is probably related to the granitic pluton in the area, which is part of a regionally extensive Upper Cretaceous and Lower Tertiary plutonic suite (Hoare and Coonrad, 1978).
Alteration of deposit Silicification and oxidation.

Production and reserves

Workings or exploration Reconnaissance geochemical sampling has been completed in the area (Cieutat and others, 1988; Hessin and others, 1978 [OF 78-9-Q; OF 78-9-M]).
Indication of production None

References

MRDS Number DE00940

References

Reporters Travis L. Hudson
Last report date 3/20/2001