Unnamed (at head of tributary to Post River)

Occurrence, Inactive

Commodities and mineralogy

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

Geographic location

Quadrangle map, 1:250,000-scale MG
Quadrangle map, 1:63,360-scale A-1
Latitude 62.018
Longitude -153.464
Nearby scientific data Find additional scientific data near this location
Location and accuracy This unnamed occurrence is located at the base of a steep north-facing cliff near the cirque headwall of an unnamed northwest flowing tributary of Post River. It is at an elevation of 4,500 feet (1,372 m) in the NE1/4 sec. 10, T. 22 N., R. 23 W., of the Seward Meridian. The occurrence corresponds to map number 34 in Bundtzen, Harris, and Gilbert (1997). The reporter sampled the site in 1988; at station no. 88BT163.

Geologic setting

Geologic description

This unnamed occurrence consists of a series of N70W, steeply dipping joints and fractures filled with quartz, pyrite, and euhedral galena grains. Width and strike length of the mineralized area was not determined. Host rock is a medium-grained, phaneritic variant of the Hartman pluton (Bundtzen, Harris, and Gilbert, 1997), which has been dated by K-Ar methods as 37.9 Ma (Solie and others, 1991). A strong ferricrete gossan is associated with the sulfide-bearing stockwork veins. One chip sample of of mineralized stockwork veins contained 500 ppm arsenic, 20 ppb gold, and 340 ppm zinc (Bundtzen, Harris, and Gilbert, 1997). Lead was not analyzed.
Geologic map unit (-153.466230699992, 62.0173833094469)
Mineral deposit model Polymetallic vein (Cox and Singer, 1986; model 22c).
Mineral deposit model number 22c
Age of mineralization Mineralization undated; host pluton is 37.5 Ma (Solie and others, 1991).
Alteration of deposit Strong ferricrete alteration.

Production and reserves

Workings or exploration The reporter visited the site in 1988. One chip sample of mineralized stockwork veins contained 500 ppm arsenic, 20 ppb gold, and 340 ppm zinc. Lead was not analyzed (Bundtzen, Harris, and Gilbert, 1997).
Indication of production None
Reserve estimates None.