Fog

Prospect in Alaska, United States with commodities Silver, Gold, Arsenic, Copper, Mercury, Molybdenum

Geologic information

Identification information

Deposit ID 10308470
Record type Site
Current site name Fog
Alternate or previous names Steeple Mountain

Geographic coordinates

Geographic coordinates: -168.26237, 53.26907 (WGS84)
Relative position The Fog prospect is located approximately 1 1/2 miles southeast of VABM Ande and may correspond to Christie's (1974) color anomaly 29. The site is part of the Steeple Mountain prospect of Kennecott (Simpson, 1985; Bundtzen and others 1990, locality 25). The site location is accurate to within 1/2 mile.. This site is one of many occurrences or prospects that occur within a 5 square-mile area, mostly within T. 80 S., R. 131 W., of the Seward Meridian. The center of this area is approximately located at VABM Ande.
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Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Silver Primary
Gold Primary
Arsenic Secondary
Copper Secondary
Mercury Secondary
Molybdenum Secondary

Materials information

Materials Type of material
Chalcopyrite Ore
Gold Ore
Molybdenite Ore
Pyrite Ore
Quartz Gangue

Alteration

  • (Local) The volcanic rocks exhibit regional propylitic alteration and localized silicification and potassium flooding or secondary growth on primary feldspars. Quartz veins exhibit pyritization and silicification in the surrounding wall rock. Some pyrite-filled fractures show narrow kaolinite-epidote-sericite alteration envelopes. No argillic alteration has been recognized.

Mineral occurrence model information

Model code 106
USGS model code 25b
Deposit model name Epithermal vein, Creede
Mark3 model number 58

Nearby scientific data

(1) -168.26237, 53.26907

Comments on the geologic information

  • Geologic Description = This site is similar in character to the Wind prospect (ARDF number UK007) and is marked by a color anomaly measuring approximately 7000 x 4000 feet. Quartz veins are hosted by propylitized volcanic rocks of Tertiary age. The volcanic rocks exhibit localized silicification, especially near the quartz veins. Some 20 veins thicker than 6 inches were mapped by Battle Mountain Exploraton (Randolph and Ellis, 1989, pg. 21). These generally strike east-west or northwest, and crop out over distances of several hundred feet, although their actual length may be much greater. The quartz is usually white and contains few visible sulfides. The veins are enriched in arsenic, mercury, and molybdenum and locally in gold and silver. The highest metal values obtained are: 400 ppm arsenic, 107 ppm copper, 8.1 ppm gold, 1600 ppb mercury, 90 ppm molybdenum, 3.4 ounces silver per ton, and 46 ppm zinc (Christie, 1974; Randolph and Ellis, 1989).
  • Age = Late Tertiary or younger.

Economic information

Economic information about the deposit and operations

Development status Prospect

Comments on exploration

  • Status = Inactive

Mining district

District name Aleutian Islands

Comments on the workings information

  • Workings / Exploration = In 1975 the Aleut-Quintana-Duval JV did reconnaissance mapping and sampling of this prospect as a followup of the discovery of numerous color anomalies. Analyses of 9 rock samples indicated values of up to 107 ppm copper, <0.01 ppm gold, 6.5 ppm molybdenum, 1.5 ppm silver, and 46 ppm zinc (Christie, 1974). Kennecott sampled and mapped in this general area in 1985 (Simpson, 1985). Battle Mountain Exploration in 1989 did detailed mapping, sampling and geophysics at this site. The sampling (141 rock-chip and 87 channel samples) gave values of up to 400 ppm arsenic, 8.1 ppm gold, 1600 ppb mercury, 90 ppm molybdenum, and 3.4 ounces per ton silver (Randolph and Ellis, 1989).

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Alaska Resource Data File ARDF UK008

Bibliographic references

  • Deposit

    Christie, J.S., 1974, Aleut-Quintana-Duval 1974 joint venture, final report: Unpublished Quintana Minerals Corporation report, 24 p., 3 appendices, 2 maps. (Report held by the Aleut Corporation, Anchorage, Alaska.)

  • Deposit

    Randolph, D.B., and Ellis, W.T., 1989, Unalaska project, 1989 final report: Battle Mountain Exploration Company, Alaska District, 41 p., 5 appendices, 11 plates, various scales. (Report held by the Aleut Corporation, Anchorage, Alaska.)

  • Deposit

    Bundtzen, T.K., Swainbank, R.C., Deagen, J.R. and Moore, J.L., 1990, Alaska's mineral industry 1989: Alaska Division of Geological and Geophysical Surveys Special Report 44, 100 p.

  • Deposit

    Simpson, D.F., 1986, Aleutian Islands project, 1985 final report: Kennecott-Alaska Exploration Company, 54 p. (Report held by the Aleut Native Corporation, Anchorage, Alaska).

Comments on the references

  • Primary Reference = Randolph and Ellis, 1989

General comments

Subject category Comment text
Deposit Model Name = Creede epithermal veins? (Cox and Singer, 1986; model 25b)
Deposit Other Comments = This site is on land conveyed, patented, or selected by the Aleut Native Corporation.

Reporter information

Type Date Name Affiliation Comment
Reporter 27-JAN-00 S.H. Pilcher U.S. Geological Survey