|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||Lower Willow Creek is a major, west tributary to the Casadepaga River. The mouth of Lower Willow Creek is is 0.9 miles downstream from Casadepaga and across from the mouth of Ruby Creek (SO096). This is locality 76 of Cobb (1972, MF 445; 1978, OF 78-181). Cobb (1972, MF 445) shows the lower 5 miles of this creek as having been placer mined but Sainsbury and others (1972, OFR 511) show tailings along 1.6 miles of the drainage starting about 1.2 miles upstream rom the mouth.|
Geologic descriptionThis west tributary of the Casadepaga River, lower Willow Creek, is incised as much as 30 feet into terraces of its drainage and, near its mouth, terraces of the Casadepaga River. Bedrock is exposed at many locations along Lower Willow Creek (Sainsbury and others, 1972, OFR 511) and placer mining has taken place at least locally for a distance of 5 miles upstream from the mouth. Sainsbury and others (1972) show tailings along 1.6 miles of the drainage starting about 1.2 miles upstream from the mouth. Benches are present on both sides of creek but the richest were on the north bank between Cahill and Rocky Creeks where mining is reported (Smith, 1910). The gold from the active drainage was both fine and coarse with nuggets up to about 0.1 ounce. Bedrock in Lower Willow Creek is a pelitic schist assemblage that may be Cambrian or Precambrian in age that is in contact with a lower Paleozoic metasedimentary assemblage to the west (Till and others, 1986).
|Geologic map unit||(-164.424618300166, 64.8152573794864)|
|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 170 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||Placer mining has taken place at least locally for a distance of 5 miles upstream from the mouth. Sainsbury and others (1972, OFR 511) show tailings along 1.6 miles of the drainage starting about 1.2 miles upstream from the mouth. Most of the mining was between 1900 and 1915 and a dredge was operated between 1911 and 1915 (Cobb, 1972, OF 78-181).|
|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.
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.
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|