|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 location is at the mouth of Lower Willow Creek (SO091) and Ruby Creek (SO096), 0.9 miles downstream from the old town of Casadepaga and at an elevation of about 320 feet. It is locality 78 of Cobb (1972, MF 445; 1978, OF 78-181).|
Geologic descriptionThe 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 pronounced 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 the 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). Sainsbury and others (1972, OFR 511) show placer tailings along the west side of the river for 0.3 miles downstream from the mouth of Lower Willow Creek (SO091). A dredge operated in the vincinity of Ruby Creek and between Ruby and Banner Creeks in 1913 and in the 1930s (Cobb, 1978, OF 78-181).
|Geologic map unit||(-164.344615061962, 64.8082582192738)|
|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 and its major tributaries (including Lower Willow Creek) indicate that more than one cycle of erosion and deposition has developed placer deposits in the area. The low elevations between 1780 and 270 feet along the first 11 miles of the river, suggest that Quaternary sea level fluctuations could have influenced placer development.|
|Workings or exploration||A dredge operated along the Casadepaga River in this vicinity as early as 1913 and in the 1930s. Sainsbury and others (1972, OFR 511) show placer tailings along the west side of the river for 0.3 miles downstream from the mouth of Lower Willow Creek.|
|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.
Sainsbury, C.L., Hudson, T.L., Ewing, R., and Marsh, W.R., 1972, Reconnaissance geologic maps of the Solomon D-5 and C-5 quadrangles, Seward Peninsula, Alaska: U.S. Geological Survey Open-File Report 72-324, 12 p., 2 sheets, scale 1:63,360.
|Reporters||Travis L. Hudson (Applied Geology)|
|Last report date||8/19/1999|