Unnamed (lower Eldorado Creek)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Au
Other commodities Ag; As; Pb
Ore minerals arsenopyrite; galena; pyrite
Gangue minerals calcite; quartz; siderite

Geographic location

Quadrangle map, 1:250,000-scale MM
Quadrangle map, 1:63,360-scale C-2
Latitude 63.5229
Longitude -150.9754
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is on a trail along lower Eldorado Creek. It is in the SE1/4 SE1/4 section 14, T. 16 S., R. 18 W., Fairbanks Meridian. The location is accurate within 500 feet. The occurrence corresponds to number 69 of Hawley and Associates (1978), 12 of Bundtzen, Smith, and Tosdal (1976), and 15 of Bundtzen (1981). The site is probably the same as an occurrence described by Morrison (1964,sample A16).

Geologic setting

Geologic description

The country rock at this occurrence is quartzite, probably of the lower Paleozoic Spruce Creek sequence (Bundtzen, 1981). The occurrence consists of a poorly exposed quartz-siderite vein that strikes strikes about N 25-35 E., and dips 80 SE. The vein contains pyrite, arsenopyrite, and probably galena. Samples assay 0.01 ounce of gold per ton, 0.16 ounce of silver per ton, as much as 0.24 percent lead, and 0.45-0.95 percent arsenic (Thornsberry, McKee, and Salisbury, 1978, v. 2, site 24; Bundtzen, 1981, table 10, number 15). Morrison (1964) reported pyrite and arsenopyrite in quartz-calcite veins at this or a nearby locality. A sample assayed 0.04 ounce of gold per ton.
Geologic map unit (-150.977684951705, 63.522392881229)
Mineral deposit model Low-sulfide Au?-quartz vein (Cox and Singer, 1986; model 36a?).
Mineral deposit model number 36a?
Age of mineralization The deposit is assumed to be Eocene (see record MM091).

Production and reserves

Workings or exploration The occurrence is a natural exposure in a road cut. There are no workings.
Indication of production None

Additional comments

The occurrence is in Denali National Park and Preserve. It is probably within the boundary of a former placer claim on Eldorado Creek.

References