|Quadrangle map, 1:250,000-scale||OP|
|Quadrangle map, 1:63,360-scale||B-2|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||Eldorado Creek is a north-flowing tributary to Madison Creek. Mining and prospecting activity took place at both the head and the mouth of Eldorado Creek. The coordinates are for the placer mine near the mouth of Eldorado Creek in the SE1/4, sec. 33, T. 23 S., R. 10 E., Kateel River Meridian. The location is accurate within 1 mile.|
The bedrock along the lower part of Eldorado Creek is volcanic; the upper part is underlain by chert, argillite, and volcaniclastic rocks. A Cretaceous or Tertiary monzonite pluton intrudes the strata in the uppermost part of the creek (Chapman and others, 1987). The monzonite contains large feldspar phenocrysts and stockwork quartz veining and is heavily weathered at the surface to quartz and feldspar (S. Dashevsky, written communication, 2000). This monzonite pluton is the likely source of the gold in Eldorado Creek (Bundtzen and others, 1987).
Roehm (1937) documents prospecting at an open cut along Eldorado Creek, groundsluicing at its mouth, and prospecting at the head of the creek.Also see OP008-012.
|Geologic map unit||(-156.930396895919, 63.4459680180277)|
|Mineral deposit model||Placer Au (Cox and Singer, 1986; model 39a)|
|Mineral deposit model number||39a|
|Age of mineralization||Quaternary. The source of the gold at Eldorado Creek may be the Cretaceous or Tertiary monzonite pluton exposed near the headwaters of the creek (Bundtzen and others, 1987).|
|Workings or exploration||Roehm (1937) documents prospecting at an open cut along Eldorado Creek, groundsluicing at its mouth, and prospecting at the head of the creek.|
|Indication of production||Yes; small|
Bundtzen, T.K., Cox, B.C., and Veach, N.C., 1987, Heavy mineral provenance studies in the Iditarod and Innoko districts, western Alaska: Alaska Division of Geological and Geophysical Surveys Public-Data File 87-16, 25 p.
Chapman, R.M., Patton, W.W., and Moll, E.J., 1985, Reconnaissance geologic map of the Ophir quadrangle, Alaska: U.S. Geological Survey Open-File Report 85-203, 19 p., 1 sheet, scale 1:250,000.
|Last report date||8/7/2001|