Fidalgo Mining Co. (Blackney Prospect)

Past Producer in Alaska, United States with commodities Copper, Silver, Gold
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. 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 10307364
Record type Site
Current site name Fidalgo Mining Co. (Blackney Prospect)

Geographic coordinates

Geographic coordinates: -146.29723, 60.79469 (WGS84)
Relative position This mine is at an elevation of about 500 feet on the south side of Port Fidalgo, about 1.5 miles northwest of the head of Matthews Bay. It is in the SE1/4 sec. 28, T. 12 S., R. 6 W., of the Copper River Meridian. The location is accurate to within 500 ft. This mine is shown as site #21 in Cobb (1972: MF-392) and C-63 in Jansons and others (1984).

Site location context

Political divisions (FIPS codes)

Valdez-Cordova(Census area)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Cordova D-7(quadrangle 1:63,360 scale)

Cordova NW(quadrangle 1:100,000 scale)

Cordova(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Eastern Prince William Sound(hydrologic unit)

Prince William Sound(hydrologic accounting unit)

South Central Alaska(hydrologic subregion)

Alaska(hydrologic region)

Federal lands

Chugach 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
Silver Secondary
Gold Secondary

Materials information

Materials Type of material
Chalcopyrite Ore
Pyrite Ore
Pyrrhotite Ore

Mineral occurrence model information

Model code 91
USGS model code 24b
Deposit model name Massive sulfide, Besshi (Japanese deposits)
Mark3 model number 30

Nearby scientific data

(1) -146.29723, 60.79469

Economic information

Comments on the geologic information

  • Geologic Description = Most of the ore mined from this deposit was from two lens-shaped bodies of massive sulfides. The ore bodies were localized in a shear zone in interbedded volcanic and sedimentary rocks of the Tertiary Orca Group (Nelson and others, 1985; Moffit and Fellows, 1950). Sulfide minerals include chalcopyrite, pyrite, and pyrrhotite. Underground study by Jansons and others (1984) reported three main shear zones up to 30 feet wide and traceable for 4000 feet parallel to bedding. Most of the mining activity took place in 1913. The average copper grade was 13%. The mine continued to be active until 1920 (Moffit and Fellows, 1950). Workings included four adits having the following lengths: 1200 ft., 735 ft., 350 ft., and 175 ft. The following assays are reported by Jansons and others (1984). Four chip samples from the 735-foot-long adit contained from 175 ppm to 0.23% Cu; nine chip samples across the main shear zone in the 1200-foot-long adit contained 0.12% to 1.25% copper; fifteen chip samples from the rest of the adit contained 9 ppm to 0.29% Cu; and three chip samples from the 175-foot-long adit contained 300 ppm to 0.73% Cu; three chip samples from the 350-foot-long adit contained 0.17% to 0.73% Cu. Grab samples from the dump contained 1% to 6.3% Cu. Industry evaluation of the property was undertaken in 1986 (B. Ellis, personal commun., 2000).
  • Age = Tertiary based on the age of the host rocks.

Economic information about the deposit and operations

Development status Past Producer

Comments on exploration

  • Status = Inactive

Mining district

District name Copper River

Comments on the production information

  • Production Notes = 360,376 lbs. Cu and 12 oz Ag were recovered from 2,747 tons ore, which also contained as much as 0.05 oz. Au/ton.

Comments on the reserve resource information

  • Reserves = Inferred reserves: 45,500 tons @ 0.3% Cu (Jansons and others, 1984).

Comments on the workings information

  • Workings / Exploration = Most of the mining activity took place in 1913. The average copper grade was 13%. The mine continued to be active until 1920 (Moffit and Fellows, 1950). Workings included four adits having the following lengths: 1200 ft., 735 ft., 350 ft., and 175 ft. The following assays are reported by Jansons and others (1984). Four chip samples from the 735-foot-long adit contained from 175 ppm to 0.23% Cu; nine chip samples across the main shear zone in the 1200-foot-long adit contained 0.12% to 1.25% copper; fifteen chip samples from the rest of the adit contained 9 ppm to 0.29% Cu; and three chip samples from the 175-foot-long adit contained 300 ppm to 0.73% Cu; three chip samples from the 350-foot-long adit contained 0.17% to 0.73% Cu. Grab samples from the dump contained 1% to 6.3% Cu. Industry evaluation of the property was undertaken in 1986 (B. Ellis, personal commun., 2000).

Reference information

Bibliographic references

Comments on the references

  • Primary Reference = Jansons and others, 1984

General comments

Subject category Comment text
Deposit Model Name = Besshi massive sulfide (Cox and Singer, 1986; model 24b)
Deposit Other Comments = Crowe and others (1992; 1993) and Sainsbury (1993) discuss the genesis of the volcanogenic massive sulfide deposits in this area.. Chugach Alaska Corporation, Anchorage, Alaska has control of these lands.

Reporter information

Type Date Name Affiliation Comment
Reporter 10-JUN-00 S.W. Nelson U.S. Geological Survey

Beyond USGS

Supplemental information added by qvyshift.com. Not part of the original USGS MRDS record.

Authoritative Alaska resources

These are landing pages for further research — the state agencies don't currently expose per-mine deep links.