Unnamed (along Summit Creek)

Occurrence in Alaska, United States with commodities Silver, Gold, Barium-Barite, Zinc, Bismuth

Geologic information

Identification information

Deposit ID 10308247
Record type Site
Current site name Unnamed (along Summit Creek)

Geographic coordinates

Geographic coordinates: -136.12212, 59.32974 (WGS84)
Relative position This site consists of several locations along the length of Summit Creek. The center of these occurrences is somewhat arbitrarily placed near the southern edge of the SE1/4, section 22, T. 29 S., R. 55 E. of the Copper River Meridian. The site is shown as number 23 by Still and others (1991).
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Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Silver Primary
Gold Primary
Barium-Barite Primary
Zinc Primary
Bismuth Secondary

Materials information

Materials Type of material
Chalcopyrite Ore
Galena Ore
Pyrite Ore
Pyrrhotite Ore
Sphalerite Ore
Calcite Gangue
Quartz Gangue

Host and associated rocks

  • Host or associated Host
    Chronological age 29.3
    Uncertainty 1
    Stratigraphic age (youngest) Tertiary
    Chronological age 33
    Uncertainty 1
    Stratigraphic age (youngest) Tertiary

Nearby scientific data

(1) -136.12212, 59.32974

Comments on the geologic information

  • Geologic Description = According to Still and others (1991), 'Bedrock in the area consists predominately of slate and phyllite, limy slate, and minor limestone.' Stream sediment samples from the mouth of Summit Creek and from small springs near the head of Summit Creek contained up to 0.020 ppm gold, 1.2 ppm silver, 1,620 ppm zinc, 1,950 ppm barium, and 660 ppm bismuth (sheet 1, numbers 209 to 217 and F83 to F90 of Gilbert and others, 1991). Still and others (1991) also report that bedrock and float samples were collected at scattered locations along Summit Creek . Quartz-calcite-sulfide float samples from talus slopes and moraine contained up to 0.686 ppm gold, 380.9 ppm silver, 2.5% zinc, 700 ppm copper, and 4.1% lead. A stream sediment sample from below a spring surrounded by iron-stained gossan contained 1.9% zinc, and a sample of iron-stained calcite-cemented slate collected several hundred feet below this stream-sediment sample contained 1.2 % zinc. The calcite cement precipitated from the spring water contains sphalerite. Virtually the entire drainage of Summit Creek consists of slate (MacKevett and others, 1974). The Triassic or Devonian age of this unit, the Porcupine Slate (Redman and others, 1985; Gilbert and others, 1987), establishes a maximum age for the mineralization. Mineralization contained in cemented scree, ferricrete, and spring water precipitates is very young if not Recent but descriptions of float samples (Still and others, 1991) also suggest that the quartz-sulfide veins are probably of Tertiary age based on the 29.3 + 1 to 33.0 + 1 m.y. age of nearby intrusive bodies (Gilbert and others, 1987).
  • Age = the Devonian or Triassic age of the Porcupine Slate (Redman and others, 1984; Gilbert and others, 1987) establishes a maximum age for the mineralization. The veins are of probable Tertiary based on the 29.3 + 1 to 33.0 + 1 m.y. age of nearby intrusive bodies (Gilbert and others, 1987). Mineralization in ferricrete, scree cement , and spring- water precipitates is very young to Recent (Still and others, 1991).
  • Age = Chronological age is for nearby intrusive bodies. Host rock is Triassic - Devonian.

Economic information

Economic information about the deposit and operations

Development status Occurrence

Comments on exploration

  • Status = Probably inactive

Mining district

District name Juneau (Skagway subdistrict)

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Alaska Resource Data File ARDF SK036

Bibliographic references

  • Deposit

    MacKevett, E.M., Jr., Robertson, E.C., and Winkler, G.R., 1974, Geology of the Skagway B-3 and B-4 quadrangles, southern Alaska: U.S. Geological Survey Professional Paper 832, 33 p.

  • Deposit

    Redman, E.C., Retherford, R.M., and Hickok, B.D., 1984, Geology and geochemistry of the Skagway B-2 Quadrangle, southeastern Alaska: Alaska Division of Geological and Geophysical Surveys Report of Investigations 84-31, 34 p., 4 sheets, scale 1:40,000.

  • Deposit

    Gilbert, W.G., Burns, L.E., Redman, E.C., and Forbes, R.B., 1987, Preliminary bedrock geology and geochemistry of the Skagway B-3 Quadrangle, Alaska: Alaska Division of Geological and Geophysical Surveys Report of Investigations 87-2, 2 sheets, scale 1:36,200.

  • Deposit

    Gilbert, W.G., Still, J.C., Burns, L.E., Wier, K.R., and Redman, E.C., 1991, Geochemistry of Haines-Klukwan-Porcupine area, southeastern Alaska: Alaska Division of Geological and Geophysical Surveys Report of Investigations 91-5, 1 sheet, scale 1:63,360, 75 p.

  • Deposit

    Still, J.C., Hoekzema, R.B., Bundtzen, T.K., Gilbert, W.G., Wier, K.R., Burns, L.E., and Fechner, S.A., 1991, Economic geology of Haines-Klukwan-Porcupine area, southeastern Alaska: Alaska Division of Geological and Geophysical Surveys Report of Investigations 91-4, 156 p., 5 sheets, scale 1:63,360.

Comments on the references

  • Primary Reference = Still and others, 1991

Reporter information

Type Date Name Affiliation Comment
Reporter 04-FEB-01 T.C. Crafford T. Crafford & Associates