Super Cub Ridge

Occurrence, Active

Commodities and mineralogy

Main commodities Fe
Other commodities Zn
Ore minerals magnetite; sphalerite
Gangue minerals chlorite; quartz; sericite

Geographic location

Quadrangle map, 1:250,000-scale MH
Quadrangle map, 1:63,360-scale B-1
Latitude 63.2752
Longitude -144.0747
Nearby scientific data Find additional scientific data near this location
Location and accuracy The Super Cub Ridge occurrence is about 2.5 miles southeast of the confluence of the Robertson River and Rumble Creek at an elevation of about 5,500 feet. It is about one-half mile north-northeast of the center of section 9, T. 17 N., R. 7 E., Copper River Meridian. The location is accurate.

Geologic setting

Geologic description

Pods of pyrrhotite-magnetite skarn occur in the Tushtena Pass unit at the contact with a gabbroic sill (S.S. Dashevsky, written communication, 2002). The Tushtena Pass unit consists mainly of medium- to coarse-grained calcareous quartz-sericite-chlorite schist with carbonate interbeds. The schist is typically green to gray and laminated to layered and contains quartz eyes. Discontinuous bands of siliceous limestone, dolomitic marble, and black pyritic metasiltstone are common. A poorly exposed graphitic member in its upper part is a stratigraphic marker that can be traced by electromagnetic surveys. Quartz-carbonate veins and bands are characteristic of the Tushtena Pass unit. It is intruded and thickened by gabbroic sills and dikes, many of which are associated with local hornfelsing in nearby rocks.
Geologic map unit (-144.076951936642, 63.2748256413581)
Mineral deposit model Iron skarn (Cox and Singer, 1986; model 18d).
Mineral deposit model number 18d
Age of mineralization Mid-Triassic, on the basis of the U-Pb zircon age of gabbroic bodies that are related to this deposit (Dashevsky and others, 2003).

Production and reserves

Indication of production None

Additional comments

Unpublished data cited is available for viewing by contacting Grayd Resources Inc. in Vancouver, B. C., Canada (, or Northern Associates Inc. in Fairbanks, Alaska.