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Unnamed (near Post River)

Occurrence in Alaska, United States with commodities Arsenic, Gold, Zinc, Antimony
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Sections on this page
  1. Identification information
  2. Geographic coordinates
  3. Site location context
  4. Geographic areas
  5. Commodities
  6. Materials information
  7. Alteration
  8. Mineral occurrence model information
  9. Host and associated rocks
  10. Nearby scientific data
  11. Economic information about the deposit and operations
  12. Mining district
  13. Links to other databases
  14. Bibliographic references
  15. General comments
  16. Reporter information

Geologic information

Identification information

Deposit ID 10307880
Record type Site
Current site name Unnamed (near Post River)

Geographic coordinates

Geographic coordinates: -153.44881, 62.06248 (WGS84)
Relative position This unnamed occurrence is located in a northeast-facing slope near a saddle between two northeast-flowing tributaries of Post River. It is at an elevation of 5,180 feet (1,579 m) in the SW1/4 sec. 23, T. 23 N., R. 23 W., of the Seward Meridian. The occurrence corresponds to map number 33 in Bundtzen, Harris, and Gilbert (1997) The reporter investigated the site in 1988; at station nos. 88BT150-151.

Site location context

Political divisions (FIPS codes)

Bethel(Census area)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

McGrath A-1(quadrangle 1:63,360 scale)

McGrath SE(quadrangle 1:100,000 scale)

McGrath(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Upper Kuskokwim River(hydrologic accounting unit)

Southwest(hydrologic subregion)

Alaska(hydrologic region)

Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Arsenic Critical Primary
Gold Primary
Zinc Critical Primary
Antimony Critical Secondary

Materials information

Materials Type of material
Antimony Ore
Pyrite Ore
Quartz Gangue

Alteration

  • (Local) Strong silicification and ferricrete gossan.

Mineral occurrence model information

Model code 106
USGS model code 25b
Deposit model name Epithermal vein, Creede
Mark3 model number 58

Host and associated rocks

  • Host or associated Host
    Rock type
    Stratigraphic age (youngest) Eocene

Nearby scientific data

(1) -153.44881, 62.06248
ListMap

Economic information

Comments on the geologic information

  • Geologic Description = This unnamed occurrence consists of significant amounts of cross-cutting quartz-sulfide stringers and stockwork in dacite-andesite flows and tuffs of the Eocene Terra Cotta Volcanic Field (Bundtzen, Harris, and Gilbert, 1997). Individual veins range from 2 to 10 centimeters thick and contain 3 to 8 percent pyrite and a bladed Sb mineral - probably stibnite. An elongate, SE to NW-trending, 45 meter wide by 110 meter long area of hydrothermal alteration contains intense silicification of andesite and strong ferricrete gossan. About 10 percent of the area is a sulfide gossan. A northeast- trending fault breccia cuts off the sulfidized zone on the southeast; the northeast limit of the mineralized area is obscured by talus and a snow field (present in 1988). Two grab samples of sulfide-quartz stockwork contain up to 4,200 ppm arsenic, 360 ppb gold, 150 ppm antimony, and 2,100 ppm zinc (Bundtzen, Harris, and Gilbert, 1997).
  • Age = Unknown; hosted in Eocene Terra Cotta Volcanic Field (Solie and others, 1991).

Economic information about the deposit and operations

Development status Occurrence

Comments on exploration

  • Status = Inactive

Mining district

District name McGrath

Comments on the workings information

  • Workings / Exploration = The reporter found the mineralization during geologic mapping for the Alaska Division of Geological and Geophysical Surveys in 1988 (Bundtzen, Harris, and Gilbert, 1997). Two grab samples of sulfide-quartz stockwork contain up to 4,200 ppm arsenic, 360 ppb gold, 150 ppm antimony, and 2,100 ppm zinc.

Reference information

Comments on the references

  • Primary Reference = Bundtzen, Harris, and Gilbert, 1997

General comments

Subject category Comment text
Deposit Model Name = Creede epithermal vein (?) (Cox and Singer, 1986; model 25b).

Reporter information

Type Date Name Affiliation Comment
Reporter 09-DEC-98 T.K. Bundtzen Pacific Rim Geological Consulting

Beyond USGS

Supplemental information added by qvyshift.com. Not part of the original USGS MRDS record.

Maps centered on this site

Authoritative Alaska resources

These are landing pages for further research — the state agencies don't currently expose per-mine deep links.