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Tsirku Silver

Occurrence in Alaska, United States with commodities Silver, Copper, Lead, Zinc, 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. Mineral occurrence model information
  8. Host and associated rocks
  9. Nearby scientific data
  10. Economic information about the deposit and operations
  11. Mining district
  12. Links to other databases
  13. Bibliographic references
  14. General comments
  15. Reporter information

Geologic information

Identification information

Deposit ID 10308246
Record type Site
Current site name Tsirku Silver

Geographic coordinates

Geographic coordinates: -136.05212, 59.31974 (WGS84)
Relative position This occurrence is centered at an elevation of 3,800 feet about 1.1 mile east of the Tsirku River and 4.0 miles, N59W from the summit of Chunekukleik Mountain. It is in the approximate center of a northwest- trending elongate area with several occurrences of ore minerals that is about 1/2 mile long and 1/4 mile wide. This area is shown as number 25 on sheet of Still and others (1991).

Site location context

Political divisions (FIPS codes)

Haines(Borough)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Skagway B-3(quadrangle 1:63,360 scale)

Skagway SE(quadrangle 1:100,000 scale)

Skagway C(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Chilkat-Skagway Rivers(hydrologic unit)

Northern Southeast Alaska(hydrologic accounting unit)

Southeast Alaska(hydrologic subregion)

Alaska(hydrologic region)

Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Silver Primary
Copper Primary
Lead Primary
Zinc Critical Primary
Gold Secondary

Materials information

Materials Type of material
Galena Ore
Malachite Ore
Pyrite Ore
Sphalerite Ore
Quartz Gangue

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 Host
    Rock type
    Stratigraphic age (youngest) Paleogene
    Chronological age 33
    Stratigraphic age (youngest) Paleogene
    Chronological age 29.3

Nearby scientific data

(1) -136.05212, 59.31974
ListMap

Economic information

Comments on the geologic information

  • Geologic Description = Still and others (1991) informally named this occurrence 'Tsirku Silver'. They describe it as, '...scattered, narrow, discontinuous silver-bearing zinc-galena-quartz veins hosted in dolomite and limy slate.' A representative chip sample of the highest grade vein contained 0.48 ppm gold, 653.5 ppm silver, 18.4 % zinc, and 6.2 % copper. According to Gilbert and others (1987), the veins occur within a 6-square-mile area immediately east of the Tsirku River that is cut by a swarm of felsic, intermediate, and mafic dikes. The dikes are probably Tertiary in age, based on a 29.3 + 1 to 33.0 + 1 m.y. age of nearby quartz diorite and granodiorite bodies (MacKevett and others, 1974). The probable Devonian or Mississippian age of the host rocks (Gilbert and others, 1987) establishes a maximum age for the veins. More likely, the veins are the same inferred Tertiary age as the dikes.
  • Age = the veins must be younger than the Devonian to Mississippian age of the host rocks (Gilbert and others, 1987) and are probably about the same age as the dikes in the area, which are inferred to be 29.3 + 1 to 33.0 + 1 m.y. based on the age of nearby quartz diorite and granodiorite (MacKevett and others, 1974).
  • Age = Chronological age is for the nearby quartz diorite and granodiorite. Host rock is Mississippian - Devonian.

Economic information about the deposit and operations

Development status Occurrence

Comments on exploration

  • Status = Probably inactive

Mining district

District name Juneau (Skagway subdistrict)

Comments on the workings information

  • Workings / Exploration = This occurrence was discovered in 1986 during the Bureau of Mines study reported in Still and others (1991).

Reference information

Bibliographic references

Comments on the references

  • Primary Reference = Still and others, 1991

General comments

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

Reporter information

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

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.