PMRGX-4

Occurrence, Inactive

Commodities and mineralogy

Main commodities Ag; Au; Cu
Ore minerals pyrite

Geographic location

Quadrangle map, 1:250,000-scale PM
Quadrangle map, 1:63,360-scale A-5
Latitude 55.085
Longitude -161.593
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is located just south of a perennial stream outlet on the west shore of Poperechnoi Island (Christie, 1974, color anomaly 69; Wilson and others, 1988, locality 53). It is referred to as PMRGX-4 in Wilson and others (1988). The location is accurate to within 1,200 feet.

Geologic setting

Geologic description

This site represents a spotty color anomaly 1 mile in diameter (Christie, 1974, color anomaly 69), developed around granodiorite that intrudes upper Miocene volcanic and epiclastic rocks (Wilson and others, 1995). Christie's examination was brief, and he examined only the edge of the anomaly. He reported probable propylititc alteration, and collected two silt samples, one of which contained 0.02 ppm gold. Mapping in the mid-1980s by the U.S. Geological Survey elsewhere in this general area revealed a hypabyssal andesite intrusion into mineralized sandstone of the Oligocene to Miocene Belkofski Formation (Wilson and others, 1988). Samples of mineralized rock were anomalous in copper and silver.
Geologic map unit (-161.594990542575, 55.0841508889886)
Age of mineralization Miocene or younger.
Alteration of deposit Christie (1974) reported epidote and chlorite, indicating probable propylitic alteration.

Production and reserves

Workings or exploration Christie (1974) collected two silt samples, one of which contained 0.02 ppm gold. Rock samples AJm733-734 collected elsewhere in the general area by the U.S. Geological Survey in the mid-1980s (samples 84AJm733-734) were reported to be anomalous in copper and silver (Wilson and others, 1988).
Indication of production None

Additional comments

This site is on land selected by the Aleut Corporation.

References