Unnamed (north of mouth of the West Fork Chistochina River)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Fe
Ore minerals magnetite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale MH
Quadrangle map, 1:63,360-scale A-2
Latitude 63.1679
Longitude -144.9581
Nearby scientific data Find additional scientific data near this location
Location and accuracy The occurrence is about 2 miles north of the confluence of the Chistochina River and the West Fork Chistochina River at an elevation of about 5,450 feet. The occurrence is in the SW1/4NW1/4 section 19, T. 20 S., R. 15 E., Fairbanks Meridian. It corresponds to locality 12 on figure 2 of Rose (1967).

Geologic setting

Geologic description

The rocks at the site consist of andesite to dacite agglomerate, flows, and tuff of the Chisna Formation (Rose, 1967). The volcanic rocks probably correlate with Tetelna Volcanics of Pennsylvanian age or Slana Spur Formation of Pennsylvanian to Permian age (Richter and Dutro, 1975).
Rose (1967) found several boulders of quartz-magnetite rock at this location; the underlying deposit is probably similar to the replacement deposit of quartz-hematite-magnetite at MH280. Both sites are about one-quarter mile west of a prominent quartz monzonite dike.
Geologic map unit (-144.96032232506, 63.1674987955973)
Mineral deposit model Fe skarn? (Cox and Singer, 1986; model 18d?).
Mineral deposit model number 18d?
Age of mineralization Possibly related to Pennsylvanian to Permian volcanic rocks or to Mesozoic quartz monzonite.
Alteration of deposit Probable replacement of intermediate volcanic rocks by quartz and magnetite.

Production and reserves

Workings or exploration Geologic mapping only.
Indication of production None