Eldorado Creek

Mine, Active?

Commodities and mineralogy

Main commodities Au
Ore minerals gold

Geographic location

Quadrangle map, 1:250,000-scale SO
Quadrangle map, 1:63,360-scale C-4
Latitude 64.583
Longitude -163.764
Nearby scientific data Find additional scientific data near this location
Location and accuracy Eldorado Creek flows south to its mouth on Norton Sound, 1 mile west of Bluff. It is the first stream west of Daniels Creek and placer mining here is only 0.8 miles northwest of the Daniels Creek placer mine (ARDF SO006). Placer mining took place over a distance of 3,000 feet downstream from an area of metasedimentary schist bedrock that trends across the drainage at an elevation of about 75 feet. This is locality 100 of Cobb (1972, MF 445; 1978, OF 78-181).

Geologic setting

Geologic description

Placer gold was discovered on Eldorado Creek by 1902 (Collier and others, 1908), soon after discovery of the rich placers at nearby Bluff and Daniels Creek (ARDF localities SO134 and SO006). Some cinnabar is reported to be present in the Eldorado Creek placer (Cathcart, 1922). Open-cut placer mining took place over a distance of 3,000 feet downstream from an area of metasedimentary schist bedrock that trends across the drainage at an elevation of about 75 feet (Herreid, 1965; Mulligan, 1971). The bedrock through most of the mined area is a 'rough' marble but one pit, separate from the stream channel workings, is 100 by 200 feet in area and possibly 30 to 50 feet deep (Mulligan, 1971). Mulligan (1971) suggests that this pit may be the location of a sink hole. Mulligan also noted that a shaft on the east side of Eldorado Creek, 600 feet from the creek and 3,000 feet inland from the beach, was associated with placer mining equipment and might indicate the presence of a residual placer deposit on schist bedrock here. The marble and intercalated metasedimentary schist of the area are lower Paleozoic (Till and others, 1986).
Geologic map unit (-163.766584636441, 64.5822630262684)
Mineral deposit model Placer Au-PGE (Cox and Singer, 1986; model 39a).
Mineral deposit model number 39a
Age of mineralization Quaternary; the placer deposits here are at low enough elevation (about 50 to 100 feet) to have been influenced by Quaternary sea level fluctuations.

Production and reserves

Workings or exploration Open-cut placer mining took place over a distance of 3,000 feet downstream from an area of schist that trends across the drainage at an elevation of about 75 feet (Herried, 1965; Mulligan, 1971). The bedrock through most of the mined area is a 'rough' marble but one pit, separate from the stream channel workings, is 100 by 200 feet in area and possibly 30 to 50 feet deep (Mulligan, 1971). Mulligan (1971) suggests that this pit may be the location of a sink hole. Mulligan also noted that a shaft on the east side of Eldorado Creek, 600 feet from the creek and 3,000 feet inland form the beach, was associated with placer mining equipment and might indicate the presence of a residual placer deposit on schist bedrock here. Most of the mining took place before WW II and was probably by hydraulic methods although a small dredge operated on the creek as recently as 1964 (Herried, 1965).
Indication of production Yes; small
Production notes The production records for Eldorado Creek are incomplete but the extent of the workings suggests that production may have exceeded 1,000 ounces (Mulligan, 1971).

References

MRDS Number 10308263

References

Reporters Travis L. Hudson (Applied Geology)
Last report date 8/19/1999