Unnamed (east of South Fork)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Pb; Zn
Other commodities As
Ore minerals limonite; pyrite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale EA
Quadrangle map, 1:63,360-scale A-2
Latitude 64.1451
Longitude -141.6958
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is along a tractor trail on a ridge top at an elevation of about 3,050 feet about 2.9 miles east-southeast of the old town of Franklin. The occurrence is in section 4, T. 27 N., R. 19 E., of the Copper River Meridian. The location is accurate.

Geologic setting

Geologic description

The rocks in the vicinity of this occurrence are interlayered Paleozoic, amphibolite-facies paragneiss, schist, amphibolite, orthogneiss, and minor marble (Werdon and others, 2001) that to the south have been intruded by small Jurassic plutons. Quartz-feldspar-white mica gneiss is iron-oxide stained and contains disseminated limonite cubes (pseudomorphs after pyrite?). Pyrite cubes approximately 1 millimeter in diameter occur within vuggy quartz veins. Many fractures are filled with limonite. An assay of this material contains 40 ppm arsenic, 444 ppm lead, and 136 ppm zinc (Werdon and others, 2000).
Geologic map unit (-141.698086664837, 64.1447744047394)
Mineral deposit model Distal Zn-Pb skarn?
Age of mineralization Paleozoic or younger; possibly related to nearby Jurassic intrusions.
Alteration of deposit Quartz-feldspar-white mica gneiss at the site is iron-oxide stained and contains disseminated limonite cubes (pseudomorphs after pyrite?).

Production and reserves

Indication of production None

References