|Quadrangle map, 1:250,000-scale||SO|
|Quadrangle map, 1:63,360-scale||D-5|
|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 on the north side of the Casadepaga River, about 4 miles upstream from the confluence of the Casdepaga and Niukluk Rivers and across from Little Dixie Creek. It was referred to as the mouth of Fool Creek by Smith (1910). This is locality 57 of Cobb (1972, MF 445; 1978, OF 78-181).|
Geologic descriptionThe only information specific to this locality along the Casadepaga River is that minor placer production occurred here early in the history of the area. 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 the river is incised into benches and terraces that have surfaces 30 to 150 feet higher than the present drainage. Gold colors are commonly present throughout 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; pyrite accompanied gold at this locality (Smith, 1910). The minor gold production here was from a low schist bedrock bench and some of the gold was fairly coarse; a 0.6 ounce nugget was recovered from spotty concentrations on bedrock. The bench gravels are frozen. Bedrock in this area is Paleozoic marble (particularly on the north side of Casadepaga River) and a pelitic schist assemblage that may be Cambrian or Precambrian in age (Till and others, 1986). 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).
|Geologic map unit||(-164.151622335401, 64.9212631587003)|
|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 of 170 to 270 feet along the first 11 miles of the river, suggest that Quaternary sea level fluctuations could have influenced placer development.|
|Workings or exploration||The only information specific to this locality along the Casadepaga River is that minor placer production occurred here early in the history of the area.|
|Indication of production||Yes; small|
Cobb, E.H., 1972, Metallic mineral resources map of the Solomon quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-445, 1 sheet, scale 1:250,000.
Cobb, E.H., 1978, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Solomon quadrangle, Alaska: U.S. Geological Survey Open-File Report 78-181, 185 p.
Collier, A.J., Hess, F.L., Smith, P.S., and Brooks, A.H., 1908, The gold placers of parts of Seward Peninsula, Alaska, including the Nome, Council, Kougarok, Port Clarence, and Goodhope precincts: U.S. Geological Survey Bulletin 328, 343 p.
Smith, P.S., 1910, Geology and mineral resources of the Solomon and Casadepaga quadrangles, Seward Peninsula, Alaska: U.S. Geological Survey Bulletin 433, 234 p.
|Reporters||Travis L. Hudson (Applied Geology)|
|Last report date||8/19/1999|