1. Mineral Resources
  2. Online Spatial Data
  3. Mineral Resource Data System (MRDS)

Commonwealth

Prospect in Alaska, United States with commodities Gold, Copper, Molybdenum, Zinc
Map
XML
JSON
KML
C
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 10001544
MRDS ID A012291
Record type Site
Current site name Commonwealth
Related records 10282781

Geographic coordinates

Geographic coordinates: -130.22174, 55.74977 (WGS84)
Relative position The presumed location of this prospect is based on Buddington's (1929, p. 111-112 [B 807]) description of the Commonwealth group of claims, which in turn refers to somewhat ambiguous landmarks that cannot be accurately located on the Ketchikan D-1 topographic map. The map site therefore is probably accurate only within about a mile. The site is in section 34, T. 70 S., R. 99 E., of the Copper River Meridian. It corresponds to loc. 14 in Elliott and others (1978).

Site location context

Political divisions (FIPS codes)

Prince of Wales-Hyder(Census area)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Ketchikan C-1(quadrangle 1:63,360 scale)

Ketchikan NE(quadrangle 1:100,000 scale)

Ketchikan(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Southern Southeast Alaska(hydrologic accounting unit)

Southeast Alaska(hydrologic subregion)

Alaska(hydrologic region)

Federal lands

Misty Fiords National Monument Wilderness(Wilderness)

Wilderness FS(Type of land area)

FS(Federal land areas administered by FS)

Tongass National Forest(National Forest)

National Forest FS(Type of land area)

FS(Federal land areas administered by FS)

Misty Fjords National Monument Wilderness(Wilderness)

Wilderness FS(Type of land area)

FS(Federal land areas administered by FS)

Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Gold Primary
Copper Primary
Molybdenum Primary
Zinc Critical Primary

Comments on the commodity information

  • Gangue = skarn minerals

Materials information

Materials Type of material
Chalcopyrite Ore
Gold Ore
Molybdenite Ore
Pyrrhotite Ore
Sphalerite Ore
Quartz Gangue

Alteration

  • (Local) Weathered pyrrhotite gives a rusty color to the surface outcrop.

Mineral occurrence model information

Model code 59
USGS model code 18b
Deposit model name Skarn Cu
Mark3 model number 8

Host and associated rocks

  • Host or associated Associated
    Rock type Plutonic Rock > Granitoid > Quartz Monzonite
  • Host or associated Host
    Rock type Metamorphic Rock > Metasedimentary Rock > Quartzite

Nearby scientific data

(1) -130.22174, 55.74977
ListMap

Economic information

Comments on the geologic information

  • Geologic Description = The country rocks in the area of the presumed site are porphyritic quartz monzonite and granodiorite of the Eocene Davis River Pluton (Smith, 1977; Berg and others, 1988). According to Buddington (1929, p. 111-112), the Commonwealth prospect(s) lie within a narrow belt of metamorphosed sedimentary rocks that form a roof pendant within the quartz monzonite. The metamorphosed strata are several hundred feet thick and include interbedded quartzite, schist, and marble. A lamprophyre dike cuts the quartz monzonite and metasedimentary rocks. The quartzite, schist, and marble have been contact metamorphosed by the intrusion of the quartz monzonite and locally contain disseminations, seams, and small masses of quartz, garnet, epidote, pyroxene, tremolite, and small amounts of sulfide minerals. The sulfide minerals include pyrrhotite, sphalerite, chalcopyrite, and molybdenite, and a quartz stringer was reported to yield gold. The age of this contact metamorphic (skarn) deposit probably is Eocene, roughly contemporaneous with the emplacement of the Davis River Pluton. The prospect was explored in the early 1900s by an 80-foot adit and an 11-foot adit.
  • Age = Eocene

Economic information about the deposit and operations

Development status Prospect
Commodity type Metallic

Mining district

District name Hyder

Comments on the workings information

  • Workings / Exploration = The prospect was explored in the early 1900s by opencuts, an 80-foot adit, and an 11-foot adit.

Reference information

Bibliographic references

Comments on the references

  • Primary Reference = Buddington, 1929 (B807)

General comments

Subject category Comment text
Deposit Model Name = Cu skarn (Cox and Singer, 1986; model 18b)
Deposit Other Comments = Site is in Misty Fiords National Monument Wilderness.

Reporter information

Type Date Name Affiliation Comment
Reporter 29-JUN-99 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.