Porcupine Creek

Occurrence, Active?

Commodities and mineralogy

Main commodities Au
Ore minerals gold

Geographic location

Quadrangle map, 1:250,000-scale SR
Quadrangle map, 1:63,360-scale B-7
Latitude 60.325
Longitude -149.4037
Nearby scientific data Find additional scientific data near this location
Location and accuracy Porcupine Creek drains into the southwest side of Kenai Lake just southwest of Porcupine Island. The creek is in T. 3 N., R 1 W., of the Seward Meridian. The placer extends from near the mouth of the creek upstream for more than 4 miles, all of which has been worked by panning or suction dredging or both. The map location is in the center of the placer in N1/2 section 26. Porcupine Creek is misnamed Primrose Creek on the 1994 Seward B-7 map. This is location P-52 of Jansons and others (1984) and is accurate to within 300 feet.

Geologic setting

Geologic description

Porcupine Creek occupies a deep, narrow, bedrock-walled canyon along most of its course; a small alluvial fan is developed along its lower portion. Gold is disseminated throughout the gravels and concentrated on bedrock. Bench gravels also contain anomalous gold values. Gold occurs as flakes and is fine in the lower part of the creek, but nuggets and coarse gold has been found in the upper section (Jansons and others, 1984). Bedrock in the Porcupine Creek drainage is metasedimentary rock of the Valdez Group of Late Cretaceous age (Nelson and others, 1985).
Production has been estimated at less than 25 ounces of gold (Jansons and others, 1984). Two samples yielded 0.0008 and 0.0022 ounce of gold per cubic yard (Jansons and others, 1984).
Geologic map unit (-149.405854121243, 60.3244391319797)
Mineral deposit model Placer Au (Cox and Singer, 1986; model 39a)
Mineral deposit model number 39a
Age of mineralization Quaternary.

Production and reserves

Workings or exploration Recreational suction dredging is occasionally done in this creek in sections previously worked. Two samples yielded 0.0008 and 0.0022 ounce of gold per cubic yard (Jansons and others, 1984).
Indication of production Yes; small
Production notes Production has been estimated at less than 25 ounces of gold (Jansons and others, 1984).

References