Unnamed (south flank of Chitsia Mountain)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Cu
Other commodities Pb; Zn
Ore minerals chalcopyrite; limonite; pyrite

Geographic location

Quadrangle map, 1:250,000-scale MM
Quadrangle map, 1:63,360-scale D-1
Latitude 63.9507
Longitude -150.2977
Nearby scientific data Find additional scientific data near this location
Location and accuracy The approximate location of this occurrence is on the south flank of Chitsia Mountain at an elevation of about 2800 feet. It probably is the NE1/4 of section 21, T. 11 S., R. 14 W., Fairbanks Meridian. The occurrence corresponds to number 75 of Bundtzen, Smith, and Tosdal (1976) and 85a of Bundtzen (1981).

Geologic setting

Geologic description

The area of this occurrence is probably underlain by phyllite and porphyritic metarhyolite of the Upper Devonian and Mississippian Totatlanika Formation (Hawley and Associates, 1978, fig. 4.1-A(3); Bundtzen, 1981). The occurrence consists of limonitic gossan developed on pyritic metarhyolite and phyllite; small amounts of chalcopyrite are associated with the pyrite. Grab samples of the limonitic material contained up to 400 ppm each of copper and lead, and 500 ppm zinc. Gold was not detected, but three samples each assayed 0.01 ounce of silver per ton (Bundtzen, 1981, occurrence 85a, table 10). The occurrence is similar geologically to those at MM007 and MM009, which are also in the Totatlanika Formation.
Geologic map unit (-150.300028360854, 63.9502108057414)
Mineral deposit model Stratabound sulfide deposit in metarhyolite.
Age of mineralization Possibly Late Devonian or Mississippian, the depositional age of the Totatlanika Formation.
Alteration of deposit Iron-oxide alteration.

Production and reserves

Workings or exploration The area has been reconnaissance mapped and sampled (Hawley and Associates, 1978, fig. 4.1-A(3); Bundtzen, 1981). There are no siginificant workings.
Indication of production None

Additional comments

The occurrence is in Denali National Park and Preserve.