Cloud

Occurrence, Inactive

Commodities and mineralogy

Main commodities Ag; Sn
Other commodities As; Bi; Pb; Sb; Zn
Ore minerals arsenopyrite; cassiterite; pb-sb-zn-ag sulfosalts
Gangue minerals quartz; tourmaline

Geographic location

Quadrangle map, 1:250,000-scale MD
Quadrangle map, 1:63,360-scale A-6
Latitude 63.201
Longitude -155.977
Nearby scientific data Find additional scientific data near this location
Location and accuracy The Cloud occurrence is located on a northeast facing spur of Cloudy Mountain at an elevation af approximately 2,400 feet (731 m) in Section 27, T. 26 S., R. 15 E., of the Kateel River Meridian. The prospect is located to within 1,000 feet (300 m).

Geologic setting

Geologic description

The geologic description is sketchy and based on a brief industry report (Anaconda Minerals Company, written communication, 1984). The Cloud prospect is not as well documented as the Win (MD060), Won-North (MD021), Won-South (MD024), and Gemini (MD023) tin-silver prospects in the Medfra quadrangle. The Cloud prospect consists of quartz-tourmaline (cassiterite-arsenopyrite-complex Pb-Sb-Zn-Ag sulfosalt) veins in hornfels about 2,000 feet (600 m) from the contact with a small monzonite stock. Vein orientations and dimensions were not given. The hornfels is thermally altered Kuskokwim Group of Upper Cretaceous age (Patton and others, 1980). Age is judged to be Late Cretaceous-early Tertiary, based on dated, genetically related intrusives nearby (Bundtzen and Miller, 1997). No specific assay data is available for this summary.
Geologic map unit (-155.979359852317, 63.2003808601577)
Mineral deposit model Tin polymetallic vein (Cox and singer, 1986; model 20b).
Mineral deposit model number 20b
Age of mineralization Age is judged to be Late Cretaceous-early Tertiary, based on dated, genetically related intrusives nearby (Bundtzen and Miller, 1997).

Production and reserves

Workings or exploration The prospect area was discovered in 1983 by Duval Corporation while following up stream sediment anomaly data released by the U.S. Geological Survey (King and others, 1980; 1983; Patton and others, 1980). No specific assay data is available.
Indication of production None
Reserve estimates None.

Additional comments

See: Won - North (MD021), Won - South (MD024), Win (MD060), and Gemini (MD023) prospects.

References