Unnamed [on Pete Dahl (Copper Sands) Island]

Occurrence, Inactive

Commodities and mineralogy

Main commodities Au
Other commodities Cr; Fe; Mn; Ni; Ti; V; Zr
Ore minerals native gold
Gangue minerals beach sand

Geographic location

Quadrangle map, 1:250,000-scale CV
Quadrangle map, 1:63,360-scale B-5
Latitude 60.35
Longitude -145.54
Nearby scientific data Find additional scientific data near this location
Location and accuracy This site is located on a barrier island in the Copper River delta. Older maps refer to this island as Pete Dahl Island (Reimnitz and Plafker, 1976); current maps name this island Copper Sands. The map site is in the SW1/4 sec. 35, T. 17 S., R. 2 W., of the Copper River Meridian. Accuracy of the location is within 1 mile.

Geologic setting

Geologic description

This occurrence consists of widespread beach and flood plain black sand deposits containing heavy minerals. Input of sands is from the Copper River where the supply of material is high. Reimnitz and Plafker (1976) report that the sands extend offshore to depths up to 50 m. They also report that the beaches of the Copper River delta contain as much gold and other heavy minerals as beaches that have been mined elsewhere along this coast. One analysis from a 5-cm-thick surface layer from the west end of the island contained 0.25 ppm Au (Reimnitz and Plafker, 1976).
Geologic map unit (-145.541987257883, 60.3494464321046)
Mineral deposit model Placer gold (Cox and Singer, 1986; model 39a)
Mineral deposit model number 39a
Age of mineralization Recent beach sands.

Production and reserves

Workings or exploration One analysis from a 5-cm-thick surface layer from the west end of the island contained 0.25 ppm Au (Reimnitz and Plafker, 1976).
Indication of production None

Additional comments

Islands in the Copper River delta change shape considerably due to storms and sedimentation supply. The islands are in the Chugach National Forest.

References