Pinnell River

Occurrence, Inactive

Commodities and mineralogy

Main commodities Au
Other commodities Ag; Cr; Pb; Zn
Gangue minerals fuchsite; quartz

Geographic location

Quadrangle map, 1:250,000-scale BN
Quadrangle map, 1:63,360-scale D-3
Latitude 65.86
Longitude -163.07
Nearby scientific data Find additional scientific data near this location
Location and accuracy Pinnell River is a major north-flowing tributary to Inmachuk River. This occurrence is on the east side of the Pinnell River valley, just above the Fairhaven ditch at an elevation of 750 feet. It is 1.8 miles south of Inmachuk River.

Geologic setting

Geologic description

A small orange gossan is developed in black dolomitic marble just above the Fairhaven ditch at an elevation of 750 feet. The marble is partially replaced by disseminations and stockwork veinlets of quartz and veinlets of fuchsite (Herreid, 1966). A gossan sample contained 0.02 ounces/ton Au, 0.023 ounces/ton Ag, 0.05 % Cu, 0.05 % Pb, 0.05 % Zn, and 0.5 % Cr (Herreid, 1966, Table 1). Most of the bedrock in the area is a metasedimentary schist and marble sequence of Lower Paleozoic age (Till and others, 1986).
Geologic map unit (-163.072694534584, 65.8593054077339)
Mineral deposit model Vein and replacement in marble?
Age of mineralization Epigenetic mineralization in metamorphic rocks of Seward Peninsula is primarily of Cretaceous age. Some lode gold deposits on southern Seward Peninsula are mid-Cretaceous in age (see Midnight Mountain, BN047).
Alteration of deposit The occurrence is oxidized and quartz veining of marble is present.

Production and reserves

Workings or exploration Small, hand dug prospecting pits may be present.
Indication of production None