Mystery Mountains West

Occurrence, Inactive

Commodities and mineralogy

Main commodities Pb; Zn
Other commodities Ag
Ore minerals galena; sphalerite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale MD
Quadrangle map, 1:63,360-scale C-4
Latitude 63.514
Longitude -154.656
Nearby scientific data Find additional scientific data near this location
Location and accuracy The Mystery Mountains West occurrence is situated on a southwesterly spur in the western-most part of the Mystery Mountains about 0.6 miles (0.9 km) northwest of Cottonwood Creek, at an elevation of 1,650 feet (503 m) in Section 8, T. 23 S., R. 22 E., of the Kateel River Meridian. Location is accurate to within 500 feet (152 m).

Geologic setting

Geologic description

The Mystery Mountains West occurrence consists of galena, sphalerite, and quartz in hornfels, and locally in quartz-tourmaline breccias in hornfels. Altered dikes cut the hornfels on the property. The Mystery Mountains West occurrence represents an outer-most metallic lead-zinc zonation observed in the Mystery Mountains mineralized area, which is thought to be a large-scale copper porphyry system. Prospects more central to the core, which include the Copenhagen Hill, Mystery Mountains-East, Frozen Creek, and Tarn prospects (MD030, MD028, MD032, MD027) are representative of a copper-gold bearing core. The Ursus prospect (MD033), like the Mystery Mountains West mineralization, represents a southern, outer lead-zinc zone (DiMarchi and others, 1997). The Mystery Mountains West occurrence is inferred to be Late Cretaceous, based on isotopic ages of plutonic rocks in Mystery Mountains (Moll and others, 1981). No assay data was found for this summary.
Geologic map unit (-154.658343476671, 63.513401381641)
Mineral deposit model Polymetallic vein deposits (Cox and Singer, 1986; model 22c).
Mineral deposit model number 22c
Age of mineralization The Mystery Mountains West occurrence is inferred to be Late Cretaceous, based on isotopic ages of plutonic rocks in Mystery Mountains (Moll and others, 1981).
Alteration of deposit Sericite in dike rocks.

Production and reserves

Workings or exploration Mystery Mountains West is one of a number of prospects related to a large porphyry copper-gold target explored in the Mystery Mountains by WGM Inc., ACNC, and ASA Inc. from 1975 to 1997 (DiMarchi and others, 1997). No assay data was found for this summary.
Indication of production None
Reserve estimates None.

Additional comments

See Ursus prospect (MD033).

References

MRDS Number 10307779

References

DiMarchi, J.J., and Frantz, P.S., 1997, Annual Report for 1997-Doyon Option Lands, Block 10: ASA Inc.-Montague Gold Joint Venture Report, Volume II: Unpublished report, 189 p. (Report held by Doyon, Limited, Fairbanks, Alaska.)
Reporters Bundtzen, T.K. (Pacific Rim Geological Consulting)
Last report date 6/6/1998