Engineer

Prospect in Alaska, United States with commodities Silver, Gold, Copper, Lead, Tungsten

Geologic information

Identification information

Deposit ID 10308773
MRDS ID A010237
Record type Site
Current site name Engineer
Related records 10000199

Geographic coordinates

Geographic coordinates: -130.21976, 56.04377 (WGS84)
Relative position The Engineer prospect is in Section 23 at an elevation of about 3750 feet on a west-facing mountainside overlooking lower Ferguson Glacier (Elliott and Koch, 1981, p. 13, loc. 42). This location is probably accurate within about a quarter of a mile.
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Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Silver Primary
Gold Primary
Copper Primary
Lead Primary
Tungsten Secondary

Materials information

Materials Type of material
Chalcopyrite Ore
Galena Ore
Pyrite Ore
Scheelite Ore
Quartz Gangue

Mineral occurrence model information

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

Nearby scientific data

(1) -130.21976, 56.04377

Comments on the geologic information

  • Geologic Description = The country rocks in the area of the Engineer prospect are pelitic metasedimentary and subordinate andesitic metavolcanic strata of the Jurassic or older Mesozoic Hazelton Group, which is underlain and locally intruded by the Triassic Texas Creek Granodiorite; and the Eocene Hyder Quartz Monzonite, which intrudes the Hazelton and Texas Creek rocks (Smith, 1977; Koch, 1996). The deposit (Buddington, 1929, p. 109-110) consists of a quartz fissure vein 1-4.5 feet (generally 2-4 feet) thick hosted by Texas Creek Granodiorite near its contact with Hazelton argillite and graywacke. The vein locally contains masses of chalcopyrite, pyrite, and galena, and rare grains of scheelite. Assays of seven specimens from the sulfide-rich masses showed 0.04-0.64 oz Au and 7.6-26 oz Ag per ton, and 11.3-55.3% Pb. Lead-isotope studies of galena from the Engineer prospect (Maas and others, 1995, p. 229-248) indicate that the deposit is Eocene in age, contemporaneous with emplacement of the Hyder Quartz Monzonite.
  • Age = Lead-isotope studies of galena from the Engineer prospect (Maas and others, 1995, p. 229-248) indicate that the deposit is Eocene in age, contemporaneous with emplacement of the Hyder Quartz Monzonite.

Economic information

Economic information about the deposit and operations

Development status Prospect
Commodity type Metallic

Comments on exploration

  • Status = Inactive

Mining district

District name Hyder

Comments on the workings information

  • Workings / Exploration = Prospect was explored, probably in the 1920's, by a 30-foot adit and several opencuts. Early assays of seven specimens from sulfide-rich masses showed 0.04-0.64 oz Au and 7.6-26 oz Ag per ton, and 11.3-55.3% Pb.

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Alaska Resource Data File ARDF BC042
USGS Mineral Resources Data System MRDS A010237
USGS Mineral Resources Data System MRDS D002758

Bibliographic references

  • Deposit

    Buddington, A.F., 1929, Geology of Hyder and vicinity, southeastern Alaska, with a reconnaissance of Chickamin River: U.S. Geological Survey Bulletin 807, 124 p.

  • Deposit

    Smith, J.G., 1977, Geology of the Ketchikan D-1 and Bradfield Canal A-1 quadrangles, Alaska: U.S. Geological Survey Bulletin 1425, 49 p.

  • Deposit

    Elliott, R.L., and Koch, R.D., 1981, Mines, prospects, and selected metalliferous mineral occurrences in the Bradfield Canal quadrangle, Alaska: U.S. Geological Survey Open-File Report 81-728-B, 23 p., 1 sheet, scales 1:250,000 and 1:63,360.

  • Deposit

    Maas, K.M., Bittenbender, P E., and Still, J.C., 1995, Mineral investigations in the Ketchikan mining district, southeastern Alaska: U.S. Bureau of Mines Open-File Report 11-95, 606 p.

  • Deposit

    Koch, R.D., 1996, Reconnaissance geologic map of the Bradfield Canal quadrangle, southeastern Alaska: U.S. Geological Survey Open-File Report 81-728-A, 35 p., 1 sheet, scale 1:250,000.

Comments on the references

  • Primary Reference = Buddington, 1929

General comments

Subject category Comment text
Deposit Model Name = Polymetallic veins

Reporter information

Type Date Name Affiliation Comment
Reporter 17-MAY-1998 H. C. Berg U.S. Geological Survey