Unnamed (in Glacier Basin)

Prospect in Alaska, United States with commodities Lead, Zinc, Molybdenum

Geologic information

Identification information

Deposit ID 10000286
MRDS ID A010329
Record type Site
Current site name Unnamed (in Glacier Basin)
Related records 10112439

Geographic coordinates

Geographic coordinates: -132.03878, 56.47975 (WGS84)
Relative position Coordinates are for approximately the center of an elongated mineralized area of about 1 1/2 square mile in area that extends from Marsha Peak southeast to Glacier Basin. The area comprise most of the eastern half of sec. 19 and the western half of section 20, T. 62 S., R. 86 E.; it includes several small mineral occurrences and two prospect that are mapped in detail on Plate 9 of Gault and others (1953).
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Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Lead Primary
Zinc Primary
Molybdenum Secondary

Materials information

Materials Type of material
Galena Ore
Sphalerite Ore
Fluorite Gangue
Quartz Gangue

Alteration

  • (Local) Deposits associated with development of pyroxene-epidote-garnet skarn.

Mineral occurrence model information

Model code 44
USGS model code 14c
Deposit model name Replacement Sn

Host and associated rocks

  • Host or associated Associated
    Rock type Plutonic Rock > Mafic Intrusive Rock > Diorite
  • Host or associated Host
    Rock type Metamorphic Rock > Granulite

Nearby scientific data

(1) -132.03878, 56.47975

Comments on the geologic information

  • Geologic Description = The prospects contain two distinct types of deposits that may be genetically related (Gault and others, 1953; Newberry and Brew, 1989). The first consists of small, discontinuous, banded galena-sphalerite-magnetite lenses probably continuous with those in Groundhog Basin (PE040) These deposits are relatively small and scattered as compared to those in Groundhog Basin, but are essentially the same in mineralogy and origin. They occur as layers in the gneiss and schist that locally includes interlayered amphibolite, marble, and calcsilicate units. These are interpreted as replacement deposits with skarn affinities. The second type of deposit consists of quartz-fluorite veins with galena that are exposed in two small adits where they cut a Tertiary rhyolite sill. Several other rhyolite bodies are nearby; most are conformable with the foliation of the metamorphic rocks. The rhyolite sills and dikes are probably cogenetic with the 20 m.y. or younger bodies associated with the Mo deposits in the area (see PE043) and/or with the 15-17 Ma zinnwaldite 'tin' granite associated with the Groundhog Basin deposits. Newberry and Brew (1989) provide analytical data for the tin content of several sulfide-rich occurrences within this site. The tin content is distinctly lower than ore samples from Groundhog Basin and their conclusion is that the Glacier Basin deposits are further from the source of the hydrothermal fluids that formed them, i.e. from the zinnwaldite 'tin' granite at the north end of Groundhog Basin.
  • Age = 15-20 Ma (see geologic description).

Economic information

Economic information about the deposit and operations

Development status Prospect
Commodity type Metallic

Mining district

District name Petersburg

Comments on the production information

  • Production Notes = None

Comments on the reserve resource information

  • Reserves = None

Comments on the workings information

  • Workings / Exploration = The deposits have been known since 1899 and two old adits with an aggregate length of about 82 feet of underground workings have been driven on galena-rich veins that cut a rhyolite sill. Several shallow pits have also been dug on various sulfide occurrences within the area, but none appears to have exposed anything of significant size.

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Mineral Resources Data System MRDS A010329
USGS Alaska Resource Data File ARDF PE041

Bibliographic references

  • Deposit

    Wright, F.E., and Wright, C.W., 1908, The Ketchikan and Wrangell mining districts, Alaska: U.S. Geological Survey Bulletin 347, 210 p.

  • Deposit

    Cobb, E.H., 1978, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Petersburg quadrangle, Alaska: U.S. Geological Survey Open-File Report 78-870, 53 p.

  • Deposit

    Cobb, E.H., 1972, Metallic mineral resources map of the Petersburg quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-415, 1 sheet, scale 1:250,000.

  • Deposit

    Grybeck, D.J., Berg, H.C., and Karl, S.M., 1984, Map and description of the mineral deposits in the Petersburg and eastern Port Alexander quadrangles: U.S. Geological Survey Open-File Report 84-837, 86 p., 1 sheet, scale 1:250,000.

  • Deposit

    Newberry, R.J., and Brew, D.A., 1989, Epigenetic hydrothermal origin of the Groundhog Basin-Glacier Basin silver-tin-lead-zinc deposits, southeastern Alaska: U.S. Geological Survey Bulletin 1903, p. 113-121.

  • Deposit

    Brew, D.A., 1997, Reconnaissance geologic map of the Petersburg B-1 quadrangle, southeastern Alaska: U.S. Geological Survey Open-File Report 97-156-C, 20 p., 1 sheet, scale 1:63,360.

  • Deposit

    Cobb, E. H., 1972, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Petersburg Quadrangle, Alaska: U.S. Geological Survey Open-File Report 78-870, 53 p.

  • Deposit

    Gault, H.R., Rossman, D.L., Flint, G.M., Jr., and Ray, R.G., 1953, Some lead-zinc deposits of the Wrangell district, Alaska: U.S. Geological Survey Bulletin 998-B, p. 15-58.

Comments on the references

  • Primary Reference = Gault and others, 1953

General comments

Subject category Comment text
Deposit Model Name = Banded Ag-Sn-Pb-Zn skarn (Cox and Singer, 1986; model 14c); fluorite-galena vein
Deposit Other Comments = Gault and others, (1953) provide detailed maps of the underground workings as well as a detailed surface geologic map that covers Groundhog Basin and extends southward to Glacier Basin to include this this site.

Reporter information

Type Date Name Affiliation Comment
Reporter 01-NOV-1998 H.C. Berg U.S. Geological Survey
Reporter 01-NOV-1998 D.J. Grybeck U.S. Geological Survey