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Star Group

Prospect in Alaska, United States with commodities Silver, Gold
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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 10001770
MRDS ID A012560
Record type Site
Current site name Star Group
Alternate or previous names Tonopah, Rex
Related records 10136441

Geographic coordinates

Geographic coordinates: -148.21329, 67.53974 (WGS84)
Relative position The Star prospect is located at an elevation of about 5,000 ft just south of St. Marys Peak (as shown on fig. 2 in Chipp, 1970); it is about 1 mile east of the Mikado mine (CH045) and 4 1/4 miles south of Squaw Lake (SE1/4 sec. 4, T. 31 N., R. 3 W., of the Fairbanks Meridian). The Tonopah claim is the easternmost claim on the Star prospect and is described as being just west of Big Creek and the upper airstrip. The location is accurate within a 1/4-mile radius.

Site location context

Political divisions (FIPS codes)

Yukon-Koyukuk(Census area)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Chandalar C-3(quadrangle 1:63,360 scale)

Chandalar N(quadrangle 1:100,000 scale)

Chandalar C(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Alaska(hydrologic region)

Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Silver Primary
Gold Primary

Materials information

Materials Type of material
Arsenopyrite Ore
Gold Ore
Scorodite Ore
Quartz Gangue

Alteration

  • (Local) Oxidation of sulfides in the quartz 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
    Stratigraphic age (youngest) Devonian

Nearby scientific data

(1) -148.21329, 67.53974
ListMap

Economic information

Comments on the geologic information

  • Geologic Description = The Star claim group (including the Tonopah claim) covers one of the four principal auriferous quartz vein systems in the Chandalar area. The vein system of the Star group, like the other vein systems in the area, is localized along steeply-dipping, northwest-trending normal faults in Devonian quartz-muscovite schist, phyllite, and quartzite, intruded by Devonian mafic sills and dikes (Chipp, 1970). In general, the veins in this area are less than 10 feet thick and are discontinuous, pinching out within a few hundred feet or less. The veins are composed principally of white crystalline to microcrystalline quartz, and their sulfide content is generally less than 5 percent. The principal sulfides in relative order of abundance are arsenopyrite, galena, sphalerite, and pyrite. Scorodite and limonite commonly are oxidation products. The quartz veins exhibit evidence of shearing, indicating that they were emplaced before or during fault movement. Major structural features in the area include large-scale northeast-trending anticlines and synclines, northeast-trending thrusts, and the northwest-trending, high-angle cross faults.? the fault zone on which the Star group is located lies between the Mikado and Summit faults (Chipp, 1970). A prospect pit on the property exposed a 6-foot-wide, partly vuggy quartz vein containing visible arsenopyrite and scorodite. The vein trends approximately N70W and dips 70 to 90 degrees northeast. A grab sample assayed 11 ppm Au. Another pit exposed vuggy, brown-stained quartz containing phyllite inclusions and minor arsenopyrite. On the Tonopah claim (west of the airstrip on upper Big Creek) trenching has exposed a 50-foot-wide fracture zone containing numerous east-west-trending, vuggy, iron-stained quartz-filled fractures 2 inches or less in width. Chipp (1970) suggests that this zone is probably the continuation of the Star vein system.? the genesis of the gold deposits in the Chandalar district is still in question. Various authors have hypothesized genetic links to a variety of felsic and mafic igneous rocks from which the gold was remobilized during metamorphism (Mertie, 1925; Boadway, 1933; Chipp, 1970; Dillon, 1982).
  • Age = Middle Cretaceous based on arguments by Dillon (1982) that the age of emplacement of the gold-bearing quartz veins of the Koyukuk and Chandalar districts was between the Neocomian metamorphism of the Devonian host rocks and their erosional unroofing and cooling in Albian time.
  • Age = Host rock is Devonian.

Economic information about the deposit and operations

Development status Prospect
Commodity type Metallic

Comments on exploration

  • Status = Inactive

Mining district

District name Chandalar

Comments on the workings information

  • Workings / Exploration = The Star prospect has been prospected by a 10-foot shaft on the Star No. 2 claim and by several pits and trenches on the Star No. 1 and 3 claims.

Reference information

Bibliographic references

Comments on the references

  • Primary Reference = Chipp, 1970

General comments

Subject category Comment text
Deposit Model Name = Low-sulfide Au-quartz veins (Cox and Singer, 1986; model 36a)
Deposit Other Comments = See also: Summit prospect (CH041), Mikado mine(CH045), Little Squaw mine (CH040).

Reporter information

Type Date Name Affiliation Comment
Reporter 17-NOV-1999 J.M. Britton U.S. Geological Survey

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.