Engineer

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

Geologic information

Identification information

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

Geographic coordinates

Geographic coordinates:	-130.21954, 56.04366 (WGS84)
Relative position	SEE LOCATION COMMENTS
(click for info)

Geographic areas

Country	State
United States	Alaska

Comments on the location information

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.

Commodities

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

Materials information

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

Host and associated rocks

Host or associated Associated

Rock type Plutonic Rock > Mafic Intrusive Rock > Diorite
Host or associated Host

Rock type Plutonic Rock > Mafic Intrusive Rock > Diorite

Rock unit name Texas Creek

Rock description Texas Creek

Host or associated	Associated
Rock type	Plutonic Rock > Mafic Intrusive Rock > Diorite

Host or associated	Host
Rock type	Plutonic Rock > Mafic Intrusive Rock > Diorite
Rock unit name	Texas Creek
Rock description	Texas Creek

Nearby scientific data

(1)	-130.21954, 56.04366	ListMap

Comments on the geologic information

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	Occurrence
Commodity type	Metallic
Significant	No

Comments on exploration

Status = Inactive

Mining district

District name	Hyder

Comments on the workings information

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
USGS	Mineral Resources Data System	MRDS	A010237
USGS	Alaska Resource Data File	ARDF	BC042
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 D1 and Bradfield Canal A-1 quadrangles, southeastern 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 81-728A, 35 p.,1 sheet, scale 1:250,000.
Deposit

Byers, F. M., and Sainsbury, C. L., 1956, Tungsten depositsof the Hyder district, Alaska: U.S. Geological Survey Bulletin 1024-F, p. 123-140.

General comments

Subject category	Comment text
Deposit	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
Deposit	QUARTZ MONZONITE.

Subject category

Comment text

Deposit

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

Deposit

QUARTZ MONZONITE.

Reporter information

Type	Date	Name	Affiliation	Comment
Reporter	01-OCT-1983	Hirschmann, M. M. (Elliott, R. L.)	U.S. Geological Survey
Updater	01-MAY-1998	Berg, H. C.	U.S. Geological Survey