Prospect in Alaska, United States with commodity Gold

Geologic information

Identification information

Deposit ID 10000408
MRDS ID A010571
Record type Site
Current site name Tidewater
Alternate or previous names Skinner
Related records 10258726

Geographic coordinates

Geographic coordinates: -150.48253, 59.50949 (WGS84)
Relative position The Tidewater prospect is on the steep, rocky, east shore of Surprise Bay in the southeast corner of the Seldovia C2 quadrangle. Surprise Bay is in the West Arm of Nuka Bay. A short adit that was at sea level prior to the 1964 earthquake is now almost completely flooded at high tide (Richter, 1970). The adit was 42 feet in length but is less 25 feet long now due to wave action. This is Cobb's (1972, MF-397) location 27 and Richter's (1970) location 10. Cobb (1972, OFR 80-87) summarized the relevant references under the name Tidewater.
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Geographic areas

Country State
United States Alaska


Commodity Importance
Gold Primary

Materials information

Materials Type of material
Arsenopyrite Ore
Gold Ore
Quartz Gangue


  • (Local) None reported although, Borden and others (1991) report other veins in the Nuka Bay district show carbonization, sulfidization, sericitization, and silicification of the wall rock adjacent to the veins.

Mineral occurrence model information

Model code 273
USGS model code 36a
Deposit model name Low-sulfide Au-quartz vein
Mark3 model number 27

Host and associated rocks

  • Host or associated Host
    Rock type Sedimentary Rock > Clastic Sedimentary Rock > Siltstone
    Rock unit name Valdez Group
    Rock description Valdez Group
    Stratigraphic age (youngest) Paleocene
    Stratigraphic age (youngest) Paleocene

Nearby scientific data

(1) -150.48253, 59.50949

Comments on the geologic information

  • Geologic Description = The prospect is in graywacke and interbedded slate of the Cretaceous Valdez Group (Richter, 1970). Prior to 1931, a 41 foot adit was driven on a vein that strikes N80E and dips 72S. The vein consists of a half-foot of sheeted quartz with scattered lens of arsenopyrite along the footwall and as much as four feet of barren quartz stockwork in the hanging wall. The country rock along the hanging wall is a graywacke that was brecciated prior to the introduction of the quartz stockwork. Assay values ranged from $38.90 to $18.00 per ton with gold at $20.67 per ounce (Pilgrim, 1933).
  • Age = Tertiary; Boden and others (1991) report other veins in the district are about 55 m.y. old.

Economic information

Economic information about the deposit and operations

Development status Prospect
Commodity type Metallic

Comments on exploration

  • Status = Inactive

Mining district

District name Homer

Comments on the production information

  • Production Notes = Probably none.

Comments on the workings information

  • Workings / Exploration = A 41 foot adit was driven in the 1930's. Richter (1970) took a single channel sample across the vein in the face of the drift, that assayed 6.5 ppm gold.

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Mineral Resources Data System MRDS A010571
USGS Alaska Resource Data File ARDF SV020

Bibliographic references

  • Deposit

    Pilgrim, E.R., 1933, Progress of lode mining in interior Alaska, 1932: Alaska Territorial Department of Mines Miscellaneous Report 194, 11 p.

  • Deposit

    Cobb, E.H., 1972, Metallic minerals resources map of the Seldovia quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-397, 1 sheet, scale 1:250,000.

  • Deposit

    Borden, J.C., Goldfarb, R.J., Gent, C.A., Burruss, R.C., and Roushey, B.H., 1992 Geochemistry of lode-gold deposits, Nuka Bay district, southern Kenai Peninsula: Geologic studies in Alaska by the U.S. Geological Survey, 1991: U.S. Geological Survey Bulletin 2041, p. 13-21.

  • Deposit

    Cobb, E.H., 1979, Summary of references to mineral occurrences (other than minerals fuels and construction materials) in the Seldovia quadrangle, Alaska: U.S. Geological Survey Open-file Report 80-87, 47 p.

  • Deposit

    Richter, D.H., 1970, Geology and lode-gold deposits of the Nuka Bay area, Kenai Peninsula, Alaska: U.S. Geological Survey Professional Paper 625-B, p. Bl-B16.

  • Deposit

    MacKevett, E.M., Jr., and Holloway, C.D., 1977, Map showing metalliferous and selected non-metalliferous mineral deposits in the eastern part of southern Alaska: U.S. Geological Survey Open-File Report 77-169-A, 99 p., 1 sheet, scale 1:1,000,000.

Comments on the references

  • Primary Reference = Richter, 1970; Pilgrim,1933

General comments

Subject category Comment text
Deposit Model Name = Low-sulfide, Au-quartz vein (Cox and Singer, 1986; model 36a)

Reporter information

Type Date Name Affiliation Comment
Reporter 18-FEB-99 Jeff A. Huber U.S. Geological Survey