Casadepaga River

Mine, Inactive

Commodities and mineralogy

Main commodities Au
Ore minerals gold
Gangue minerals garnet; magnetite

Geographic location

Quadrangle map, 1:250,000-scale SO
Quadrangle map, 1:63,360-scale D-5
Latitude 64.89
Longitude -164.19
Nearby scientific data Find additional scientific data near this location
Location and accuracy The Casadepaga River is a major west tributary to the Niukluk River. This locality is 1.3 miles upstream from the mouth of Big Four Creek (SO066) at about 210 feet elevation. This is probably located within about 3/4 mile of the coordinates. It is locality 56 of Cobb (1972, MF 445; 1978, OF 78-181).

Geologic setting

Geologic description

The Casadepaga River is a major west tributary to the Niukluk River. The first 11 miles upstream from the mouth varies from 170 to 270 feet in elevation. The next 8 to 9 miles upstream gains another 150 feet of elevation. The lower 11 miles of the river has a pronouced floodplain over most of its length but in general this river is incised into benches and terraces that have surfaces 30 to 150 feet higher than the present drainage. Gold colors are commonly present in bench gravels and mining has commonly taken place where tributaries cross the benches and rework these gravels (Collier and others, 1908). Heavy mineral concentrates from various parts of the drainage commonly contain garnet and magnetite. In general, bedrock was not exposed by early mining operations along the lower part of this river. As noted by Smith (1910), the depth to bedrock is known to vary from as much as 57 feet at the mouth of Penelope Creek (SO079) to 17 feet a half mile above the mouth of Big Four Creek (SO066). Smith (1910) noted that at this locality, an abandoned channel of the Casdepaga River (between Dixon and Dawson Creeks) was being mined by small-scale methods in 1907. The mining found some coarse gold that was spottily distributed on an irregular bedrock of schist and marble.
Geologic map unit (-164.192619772396, 64.8892618192806)
Mineral deposit model Placer Au-PGE (Cox and Singer, 1986; model 39a).
Mineral deposit model number 39a
Age of mineralization Quaternary; the numerous incised terraces along the Casadepaga River indicate that more than one cycle of erosion and deposition has developed placer deposits in the area. The low elevations between 170 and 270 feet along the first 11 miles of the river, suggest that Quaternary sea level fluctuations could have influenced placer development.

Production and reserves

Workings or exploration Small-scale surface operations recovered a little gold at this locality.
Indication of production Yes; small