1. Mineral Resources
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  3. Mineral Resource Data System (MRDS)

Unnamed (along Snow Passage)

Occurrence in Alaska, United States with commodity Fluorine-Fluorite
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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. Nearby scientific data
  9. Economic information about the deposit and operations
  10. Mining district
  11. Links to other databases
  12. Bibliographic references
  13. General comments
  14. Reporter information

Geologic information

Identification information

Deposit ID 10308064
Record type Site
Current site name Unnamed (along Snow Passage)

Geographic coordinates

Geographic coordinates: -132.94485, 56.28174 (WGS84)
Relative position Accurately known to within 300 feet in the NW1/4, section 33, T. 64 S., R. 80 E on the western side of Zarembo Island. Well-exposed locality along the wave-scoured rocky coastline on the east side of Snow Passage, Clarence Strait.

Site location context

Political divisions (FIPS codes)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Petersburg B-3 SW(quadrangle 1:24,000 scale)

Petersburg S(quadrangle 1:100,000 scale)

Petersburg(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Central Southeast Alaska(hydrologic accounting unit)

Southeast Alaska(hydrologic subregion)

Alaska(hydrologic region)

Federal lands

Tongass National Forest(National Forest)

National Forest FS(Type of land area)

FS(Federal land areas administered by FS)

Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Fluorine-Fluorite Critical Primary

Materials information

Materials Type of material
Fluorite Ore
Chalcedony Gangue
Quartz Gangue

Alteration

  • (Local) Fluorite possible formed during a degassing stage of the cooling of the rhyolite hostrock.

Nearby scientific data

(1) -132.94485, 56.28174
ListMap

Economic information

Comments on the geologic information

  • Geologic Description = Sparse fluorite occurs in Tertiary-Quaternary rhyolite over an area at least 300 feet long along the coast. The fluorite occurs as fillings in narrow, vuggy fracture zones, coating chalcedony- or quartz-encrusted fragments in breccia zones, and as geode-like bodies commonly called 'thundereggs' (Buddington, 1923). For pictures of the latter and a detailed study of their REE content and mineralogy see Philpotts and Evans (1992). Although mineralogically interesting, the site as now known is little more than a mineral occurrence. The origin of the fluorite is unclear but the simplest interpretation is that it formed during a degassing phase of the emplacement of the rhyolite in which it occurs.
  • Age = Tertiary or Quaternary; fluorite veins and fills breccia in Tertiary or Quaternary rhyolite and is either later than or part of the cooling history and emplacement of the rhyolite.

Economic information about the deposit and operations

Development status Occurrence

Comments on exploration

  • Status = Probably inactive

Mining district

District name Ketchikan

Comments on the production information

  • Production Notes = As now known, appears to be no more than an interesting mineralogical occurrence.

Comments on the workings information

  • Workings / Exploration = Long known in good exposures along the coast; no record of any exploration otherwise.

Reference information

Bibliographic references

Comments on the references

  • Primary Reference = Philpotts and Evans, 1995

General comments

Subject category Comment text
Deposit Model Name = Fluorite in rhyolite.

Reporter information

Type Date Name Affiliation Comment
Reporter 01-NOV-98 H.C. Berg and D.J. Grybeck 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.