Unnamed (on Blunt Mountain)

Occurrence in Alaska, United States with commodity Lead

Geologic information

Identification information

Deposit ID 10001621
MRDS ID A012385
Record type Site
Current site name Unnamed (on Blunt Mountain)

Geographic coordinates

Geographic coordinates: -131.39564, 55.13863 (WGS84)
Relative position This occurrence is at an elevation of about 2000 feet on Blunt Mountain, about 0.15 mile east of the summit. The site is in section 3, T. 78 S., R. 93 E., of the Copper River Meridian. It corresponds to loc. 30 in Berg (1972 [I 684]), loc. 144 in Elliott and others (1978), and loc. 40 in Karl (1992). The location is accurate within a few hundred feet.
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Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Lead Primary

Materials information

Materials Type of material
Galena Ore
Pyrite Ore
Hematite Gangue
Quartz Gangue

Alteration

  • (Local) Sericitization of trondhjemite, and oxidation of iron mineral(s) in veins to hematite(?).

Mineral occurrence model information

Model code 85
USGS model code 22c
Deposit model name Polymetallic veins
Mark3 model number 46

Host and associated rocks

  • Host or associated Associated
    Rock type Plutonic Rock > Granitoid > Granite
    Rock unit name Annette Pluton
    Rock description Annette Pluton
    Stratigraphic age (youngest) Late Silurian
    Stratigraphic age (youngest) Late Silurian
  • Host or associated Host
    Rock type Plutonic Rock > Granitoid > Tonalite > Trondhjemite

Nearby scientific data

(1) -131.39564, 55.13863

Comments on the geologic information

  • Geologic Description = The country rock in the area of this site is Silurian trondhjemite that was regionally metamorphosed to greenschist grade in Late Cretaceous time (Berg, 1972). The occurrence is in sericitized trondhjemite, and consists of sparse galena, hematite(?), and pyrite in iron-stained quartz fissure veins and pods up to 10 feet thick.
  • Age = Fissure veins probably are Late Cretaceous or younger.

Economic information

Economic information about the deposit and operations

Development status Occurrence
Commodity type Metallic

Mining district

District name Ketchikan

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Mineral Resources Data System MRDS A012385
USGS Alaska Resource Data File ARDF KC147

Bibliographic references

  • Deposit

    Berg, H.C., 1972, Geologic map of Annette Island, Alaska: U.S. Geological Survey Miscellaneous Geologic Investigations Map I-684, 8 p., 1 sheet, scale 1:63,360,

  • Deposit

    Elliott, R.L., Berg, H.C., and Karl, Susan, 1978, map and table describing metalliferous and selected nonmetalliferous mineral deposits, Ketchikan and Prince Rupert quadrangles, Alaska: U.S. Geological Survey Open-file Report, 78-73-B,17 p., scale 1:250,000.

  • Deposit

    Karl, S.M., 1992, Map and table of mineral deposits on Annette Island, Alaska: U.S. Geological Survey Open-File Report 92-690, 57 p., 1 map, scale 1:63,360.

Comments on the references

  • Primary Reference = Berg, 1972 (I 684)

General comments

Subject category Comment text
Deposit Model Name = Polymetallic veins (Cox and Singer, 1986; model 22c)

Reporter information

Type Date Name Affiliation Comment
Reporter 06-JUL-1999 H.C. Berg U.S. Geological Survey