Occurrence in Alaska, United States with commodities Silver, Tin, Arsenic, Bismuth, Lead, Antimony, Zinc

Geologic information

Identification information

Deposit ID 10307802
Record type Site
Current site name Cloud

Geographic coordinates

Geographic coordinates: -155.97997, 63.20045 (WGS84)
Relative position 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).
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Geographic areas

Country State
United States Alaska


Commodity Importance
Silver Primary
Tin Primary
Arsenic Secondary
Bismuth Secondary
Lead Secondary
Antimony Secondary
Zinc Secondary

Materials information

Materials Type of material
Arsenopyrite Ore
Cassiterite Ore
Quartz Gangue
Tourmaline Gangue

Mineral occurrence model information

Model code 77
USGS model code 20b
Deposit model name Sn-polymetallic vein

Nearby scientific data

(1) -155.97997, 63.20045

Comments on the geologic information

  • 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.
  • Ore Material = Pb-Sb-Zn-Ag sulfosalts
  • Age = Age is judged to be Late Cretaceous-early Tertiary, based on dated, genetically related intrusives nearby (Bundtzen and Miller, 1997).

Economic information

Economic information about the deposit and operations

Development status Occurrence

Comments on exploration

  • Status = Inactive

Mining district

District name Innoko

Comments on the workings information

  • Workings / 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.

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Alaska Resource Data File ARDF MD059

Bibliographic references

  • Deposit

    King, H.D., Tripp, R.B., O'Leary, R.M., and Cooley, E.F., 1983, Distribution and abundance of copper, lead, and zinc in nonmagnetic and moderately magnetic heavy-mineral- concentrate, minus-80-mesh stream-sediment, and ash of aquatic-bryophyte samples, Medfra quadrangle, Alaska: U.S. Geological Survey Open-File Report 80-811-I, 6 sheets, scale 1:250,000.

  • Deposit

    Patton, W.W., Jr., Moll, E.J., Dutro, J.T., Jr., Silberman, M.L., and Chapman, R.M., 1980, Preliminary geologic map of Medfra quadrangle, Alaska: U.S. Geological Survey Open-File Report 80-811-A, 1 sheet, scale l:250,000.

  • Deposit

    Bundtzen, T.K., and Miller, M.L., 1997, Precious metals associated with Late Cretaceous-early Tertiary igneous rocks of southwestern Alaska, in Goldfarb, R.J., and Miller, L.D., eds., Economic Geology Monograph #9, Mineral Deposits of Alaska, p. 242-286.

  • Deposit

    King, H.D., Risoli, D.A., Cooley, E.F., O'Leary, R.M., Speckman, W.A., Speisman, D.L., and Galland, D.W., 1980, Final results and statistical summary of analyses of geochemical samples from the Medfra quadrangle, Alaska: U.S. Geological Survey Open-File Report 80-811F, 134 pages.

Comments on the references

  • Primary Reference = King and others, 1983

General comments

Subject category Comment text
Deposit Model Name = Tin polymetallic vein (Cox and singer, 1986; model no. 20b)
Deposit Other Comments = See Won - North (MD021), Won - South (MD024), Win (MD060), and Gemini (MD023) prospects.

Reporter information

Type Date Name Affiliation Comment
Reporter 03-JUN-98 Bundtzen, T.K. Pacific Rim Geological Consulting