Fidalgo Mining Co. (Blackney Prospect)

Site Name

Primary: Fidalgo Mining Co. (Blackney Prospect)

---

Commodity

Primary: Copper
Secondary: Gold
Secondary: Silver

---

Location

State: Alaska
District: Copper River

---

Land Status

Not available

---

Holdings

Not available

---

Workings

Not available

---

Ownership

Not available

---

Production

Not available

---

Deposit

Record Type: Site
Operation Category: Past Producer
Operation Type: Unknown
Years of Production:
Organization:
Significant:

---

Physiography

Not available

---

Mineral Deposit Model

Model Name: Massive sulfide, Besshi (Japanese deposits)

---

Orebody

Not available

---

Structure

Not available

---

Alterations

Not available

---

Rocks

Not available

---

Analytical Data

Not available

---

Materials

Ore: Pyrrhotite
Ore: Pyrite
Ore: Chalcopyrite

---

Comments

Comment (Deposit): Model Name = Besshi massive sulfide (Cox and Singer, 1986; model 24b)

Comment (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.

Comment (Geology): Age = Tertiary based on the age of the host rocks.

Comment (Production): 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.

Comment (Exploration): Status = Inactive

Comment (Reference): Primary Reference = Jansons and others, 1984

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

Comment (Workings): 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).

Comment (Geology): 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).

---

References

Reference (Deposit): Cobb, E.H., 1972, Metallic mineral resources map of the Cordova quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-392, 1 sheet, scale 1:250,000.

Reference (Deposit): Nelson, S.W., Dumoulin, J. A., and Miller, M.L., 1985, Geologic map of the Chugach National Forest, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-1645-B, 16 p., 1 sheet, scale 1:250,000.

Reference (Deposit): Sainsbury, C.L., 1993, Geology and geochemistry of volcanogenic massive sulfide deposits and related igneous rocks, Prince William Sound, south-central Alaska, A discussion: Economic Geology, v. 88, p. 1284-1285.

Reference (Deposit): Crowe, D.E., Nelson, S.W., Brown, P.E., Shanks III, W.C., and Valley, J.W., 1992, Geology and geochemistry of volcanogenic massive sulfide deposits and related igneous rocks, Prince William Sound, south-central Alaska: Economic Geology, v. 87, p. 1722-1746.

Reference (Deposit): Crowe, D.E., Nelson, S.W., Brown, P.E., Shanks III, W.C., and Valley, J.W., 1993, Geology and geochemistry of volcanogenic massive sulfide deposits and related igneous rocks, Prince William Sound, south-central Alaska-A reply: Economic Geology, v. 88, p. 1285-1288.

Reference (Deposit): Moffit, F.H. , and Fellows, R.E. , 1950, Coper deposits of the Prince William Sound district, Alaska; Geological Survey Bullentin 963-B, p. 47-80.

Reference (Deposit): Jansons, Uldis, Hoekzema, R.B., Kurtak, J.M., and Fechner, S.A., 1984, Mineral occurrences in the Chugach National Forest, Southcentral Alaska: U.S. Bureau of Mines Open-File Report 5-84, 218 p., 2 sheets, scale 1:250,000.

---

The Top Ten Gold Producing States

These ten states contributed the most to the gold production that built the West from 1848 through the 1930s. The Top Ten Gold Producing States.