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Friday

Prospect in Alaska, United States with commodities Copper, Barium-Barite
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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. 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 10001604
MRDS ID A012367
Record type Site
Current site name Friday
Related records 10209683, 10255524

Geographic coordinates

Geographic coordinates: -131.78566, 55.16363 (WGS84)
Relative position The Friday prospect is near tidewater, about midway along the southeast shore of Nehenta Bay. The site is in sec 25, T. 77 S., R. 90 E., of the Copper River Meridian. It corresponds to loc. 122 in Elliott and others (1978). The location is accurate within 0.1 mile.

Site location context

Political divisions (FIPS codes)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Ketchikan A-6 NE(quadrangle 1:24,000 scale)

Ketchikan SW(quadrangle 1:100,000 scale)

Ketchikan(quadrangle 1:250,000 scale)

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
Copper Primary
Barium-Barite Critical Secondary

Comments on the commodity information

  • Gangue = Carbonate

Materials information

Materials Type of material
Barite Ore
Chalcopyrite Ore
Pyrite Ore
Quartz Gangue

Alteration

  • (Local) Locally conspicuous iron staining.

Mineral occurrence model information

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

Nearby scientific data

(1) -131.78566, 55.16363
ListMap

Economic information

Comments on the geologic information

  • Geologic Description = Southern Gravina Island is underlain by an assemblage of undivided Silurian or Ordovician metamorphosed bedded and intrusive rocks; a stock and associated dikes of Silurian trondhjemite that cuts the metamorphic assemblage; and a sequence of Upper Triassic carbonate, clastic, rhyolitic, and basaltic strata that unconformably overlies the older rocks (Berg, 1973, 1982; Berg and others, 1988). The rocks are complexly folded and are cut by high-angle faults and by low-angle thrust faults. In many places, the Triassic rhyolite and the rocks beneath it are permeated by microscopic particles of hydrothermal hematite, giving them a pink, purple, or red hue (Berg, 1973, p. 14).? the Friday prospect was probably staked for copper in the early 1900s (U. S. Bureau of Mines, 1977); it was mapped, and the prospect briefly examined, by the U.S. Geological Survey in 1969 (Elliott and others, 1978). Elliott and others describe the deposit as pyrite- and chalcopyrite-bearing quartz-carbonate-barite? veins in breccia zones in strongly iron-stained metamorphosed volcanic, sedimentary and intrusive country rocks. Berg (1973, pl. 1) maps the rocks at and near this prospect as Triassic basal conglomerate containing clasts of the underlying trondhjemite and metamorphic assemblage. The mineralized breccia zones probably are hosted by this conglomerate, rather than by the metamorphic unit described by Elliott and others. The country rocks at the Friday prospect are cut by a high-angle fault that strikes NE, parallel to the SE shoreline of Nehenta Bay (Berg, 1973, pl. 1). Several occurrences of barite-bearing fissure veins are in Triassic sedimentary rocks on the islands at the mouth of Nehenta Bay. The characteristics and setting of these deposits suggest that they are polymetallic veins of Late Triassic or younger age. Workings visible in 1969 were a few small pits and short tunnels.
  • Age = Late Triassic or younger.

Economic information about the deposit and operations

Development status Prospect
Commodity type Metallic

Mining district

District name Ketchikan

Comments on the workings information

  • Workings / Exploration = Workings visible in 1969 were a few small pits and short tunnels.

Reference information

Bibliographic references

Comments on the references

  • Primary Reference = Berg, 1973; Elliott and others, 1978

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 05-JUL-1999 H.C. Berg 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.