Surprise

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

Geologic information

Identification information

Deposit ID 10308692
Record type Site
Current site name Surprise

Geographic coordinates

Geographic coordinates: -160.65841, 55.18923 (WGS84)
Relative position The map site of the Surprise prospect is at an elevation of 600 feet, about 1,500 feet north-northwest of the center of sec. 3, T. 58 S., R. 75 W., Seward Meridian. The location is accurate to within 1,200 feet.
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Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Silver Primary
Gold Primary
Arsenic Secondary
Copper Secondary
Mercury Secondary
Lead Secondary
Zinc Secondary

Materials information

Materials Type of material
Gold Ore
Pyrite Ore
Quartz Gangue

Alteration

  • The host rocks exhibit propylitic and argillic alteration.

Nearby scientific data

(1) -160.65841, 55.18923

Comments on the geologic information

  • Geologic Description = The Surprise vein is approximately 10 feet in width and is composed of massive and comb quartz containing 0.5 to 3.0 percent pyrite. It strikes northeast and can be followed for 1,000 feet as a magnetic low (Trujillo and others, 1981). This previously unknown vein was penetrated in the upper part of a drill hole positioned to test another vein at depth. Host rocks are propylitized and argillized andesite flows of the late Eocene to early Oligocene Popof volcanic rocks (Wilson and others, 1995). The drill hole cut an upper 7.9 feet grading 0.012 ounce of gold and 0.07 ounce of silver per ton. A lower 3.7-foot intercept graded 0.05 ounce of gold and 0.04 ounce of silver per ton. These core intervals also assayed as much as 160 ppm copper, 90 ppm lead, 625 ppm zinc, 100 ppm arsenic, and 0.27 ppm mercury (Trujillo and others, 1981).
  • Age = Eocene of younger.

Economic information

Economic information about the deposit and operations

Development status Prospect
Commodity type Metallic

Comments on exploration

  • Status = Inactive

Mining district

District name Alaska Peninsula

Comments on the workings information

  • Workings / Exploration = In 1981, Resource Associates of Alaska explored this prospect by a 255-foot drill hole and several trenches. The best drill intercept was 3.7 feet grading 0.05 ounce of gold and 0.04 ounce of silver per ton (Trujillo and others, 1981).

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Alaska Resource Data File ARDF PM089

Bibliographic references

  • Deposit

    Trujillo, R.S., Anderson, G., MacLeod, T., Hendrick, K., Farnham, S., Peterson, J., 1981. Exploration and evaluation of the Unga-Popof-Korovan Islands portion of lands leased from Aleut Native Corporation: Resource Associates of Alaska report, 70 p., 38 map sheets, various scales. (Report held by the Aleut Corporation, Anchorage, Alaska.)

  • Deposit

    Wilson, F.H., Detterman, R.L., Miller, J. W., and Case, J.E., 1995, Geologic map of the Port Moller, Stepovak Bay, and Simeonof Island quadrangles, Alaska: U.S. Geological Survey Miscellaneous Investigation Series Map I-2272, 1 map sheet, scale 1:250,000.

Comments on the references

  • Primary Reference = Trujillo and others, 1981

General comments

Subject category Comment text
Deposit Model Name = Epithermal gold vein
Deposit Other Comments = This prospect is located on land patented by, or interim-conveyed to, the Aleut Corporation.

Reporter information

Type Date Name Affiliation Comment
Reporter 01-FEB-2001 S.H. Pilcher U.S. Geological Survey