Miss Molly

Prospect, Probably inactive

Commodities and mineralogy

Main commodities Mo; Pb; Zn
Other commodities F
Ore minerals galena; molybdenite; pyrite; sphalerite
Gangue minerals fluorite; quartz

Geographic location

Quadrangle map, 1:250,000-scale TY
Quadrangle map, 1:63,360-scale C-6
Latitude 61.73
Longitude -152.07
Nearby scientific data Find additional scientific data near this location
Location and accuracy Fernette and Cleveland (1984) locate the Miss Molly prospect on the north side of the Trimble River near the toe of the Trimble Glacier in Section 18, T. 19 N., R. 15 W. The area is mostly covered by glacial debris and dense vegetation, with good bedrock exposures along the Trimble River and in stream valleys (U.S. Bureau of Mines, 1998, MAS # 0020840031 and U.S. Bureau of Mines, 1973, localites 26 and 46). Location is known to within 100 yards.

Geologic setting

Geologic description

Fernette and Cleveland (1984) described the mineralization at Miss Molly as quartz veins with medium to coarse-grained molybdenite, pyrite, and local fluorite. Veins are regularly spaced, sub-parallel, vary from 2 to 10 cm wide, and are spaced 2 to 10 m apart. Veins occur in two zones about 545 m long and up to 150 m wide in a leucocratic, equigranular biotite granite stock. Veins locally fill joints and less commonly shears. Hydrothermal alteration up to 0.3 m wide to sericite and pyrite, occurs adjacent to veins. Grab and chip samples contain up to 0.38 percent Mo, 0.16 percent Zn and 100 ppb Au. The granite stock intrudes Mesozoic marine sediments (KJs) of the Kahiltna terrane (Fernette and Cleveland, 1984 and Nokleberg and others, 1987). Reed and Lanphere (1972) report nearby granitic plutons with K-Ar ages of 56-59 m.y. and is probably the same age as the intrusion hosting the veins.
Geologic map unit (-152.072184566612, 61.7294254320301)
Mineral deposit model Mo-bearing quartz veins
Age of mineralization Possibly related to dated Tertiary (59 - 56 m.y.) intrusions nearby. (Reed and Lanphere, 1972)
Alteration of deposit Quartz, sericite, clay, and alunite? (Fernette and Cleveland, 1984).

Production and reserves

Workings or exploration Exploration work included prospecting, rock chip geochemical sampling.
Indication of production None
Reserve estimates Moderate size and grade (Fernette and Cleveland, 1984).

Additional comments

The Miss Molly prospect is not a classic stockwork molybdenum- type occurrence.

References

MRDS Number A106253

References

Hollister, V.F., 1978, Geology of the porphyry copper deposits of the Western Hemisphere: Society of Mining Engineering, American Institute of Mining, Metallurgy, and Petroleum Engineers Inc., 218 p.
U.S. Bureau of Mines, 1998, Minerals Availability System/Minerals Industry Location System (MAS/MILS), Talkeetna quadrangle: Worldwide Web URL http://imcg.wr.usgs.gov/data.htm
Reporters Madelyn A. Millholland (Anchorage), James Riehle (USGS)
Last report date 6/1/1998