Marshall Glacier

Occurrence, Probably inactive

Commodities and mineralogy

Main commodities Cu
Ore minerals chalcopyrite; pyrite; pyrrhotite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale VA
Quadrangle map, 1:63,360-scale A-5
Latitude 61.081
Longitude -145.5099
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is about eight-tenths of a mile northeast of the toe of Marshall Glacier on an unnamed stream; it is approximately on the north boundary of section 24, T. 9 S., R. 2 W., of the Copper River Meridian. This occurrence is approximately located, perhaps within a mile or more.

Geologic setting

Geologic description

Float of massive and semimassive sulfide cobbles and boulders have been found in the drainage of Marshall Glacier (Kodosky and Teller, 1989). Minerals identified in these cobbles include chalcopyrite, pyrite, pyrrhotite, and quartz. The source and setting of this mineralization has not been identified. It is tentatively considered to be similar to other sulfide-rich occurrences in mafic metavolcanic rocks of the Valdez Group (for example, VA055 and VA144).
Geologic map unit (-145.511919440233, 61.0804861203939)
Mineral deposit model Cyprus massive sulfide? (Cox and Singer, 1986; model 24a)
Mineral deposit model number 24a?
Age of mineralization Late Cretaceous?; the host metavolcanic rocks may be ocean-floor basalts that were accreted with the enclosing flysch of the Valdez Group (Winkler and others, 1981 [OFR 80-892-A]).

Production and reserves

Workings or exploration Only reconnaissance surface examinations and sampling have taken place.
Indication of production None

References

References

Kodosky, Larry, and Teller, Steve, 1989, Economic mineral assessment of Chugach Alaska Corporation properties and selected land in the Copper, Bremner, and Tasnuna River area: Unpublished report prepared for Chugach Alaska Corporation, Anchorage, Alaska, 116 p.
Reporters Travis L. Hudson
Last report date 12/14/2001