Texas Creek Comstock

Prospect in Alaska, United States with commodities Silver, Gold, Copper, Molybdenum, Lead, Zinc, Barium-Barite

Geologic information

Identification information

Deposit ID 10093933
MRDS ID A010307
Record type Site
Current site name Texas Creek Comstock
Alternate or previous names Hyder Lead, Texas Comstock, Joe Joe, Fortuna, Alaska-Comstock, Jackson-Hummel

Geographic coordinates

Geographic coordinates: -130.25787, 56.04171 (WGS84)
Relative position The above coordinates are for the approximate center of a group of five prospects in a map area about 0.5 mile (Lat 56.039-56.044) by 1.0 mile (Long 130.246-130.265) on the mountainside south of Texas Lake (Elliott and Koch, 1981, p. 13, loc. 37). The prospects are at elevations ranging from about 3200 to 4300 feet in Sections 21 and 22. The location of the prospect area 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
Molybdenum Primary
Lead Primary
Zinc Primary
Barium-Barite Secondary

Materials information

Materials Type of material
Chalcopyrite Ore
Galena Ore
Molybdenite Ore
Pyrite Ore
Pyrrhotite Ore
Sphalerite Ore
Tetrahedrite Ore
Calcite Gangue
Chlorite Gangue
Quartz Gangue

Mineral occurrence model information

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

Host and associated rocks

  • Host or associated Associated
    Rock type Volcanic Rock (Aphanitic) > Intermediate Volcanic Rock > Andesite
    Rock unit name Texas Creek Granodiorite;
    Rock description Texas Creek Granodiorite;
  • Host or associated Host
    Rock type Sedimentary Rock > Clastic Sedimentary Rock > Siltstone
    Rock unit name Texas Creek Granodiorite
    Rock description Texas Creek Granodiorite

Nearby scientific data

(1) -130.25787, 56.04171

Comments on the geologic information

  • Geologic Description = The country rocks in the general area of these prospects include pelitic metasedimentary and subordinate andesitic metavolcanic strata of the Jurassic or older Mezozoic Hazelton Group; the Triassic Texas Creek Granodiorite, which underlies and locally intrudes the Hazelton; and the Eocene Hyder Quartz Monzonite, which intrudes both the Hazelton and Texas Creek rocks (Smith, 1977; Koch, 1996). ? Buddington (1925, p. 91-93; Cobb, 1978, p. 42-43) described a deposit, called 'Texas Creek Comstock' in his report, as quartz fissure veins up to 11 feet thick in granodiorite, metamorphosed graywacke, and tuff that contain galena, pyrite, chalcopyrite, and molybdenite. Andesite porphyry and aplite dikes cut both the granodiorite and metamorphic rocks. Assays showed 3.6-16.9 oz Ag and a trace to 0.18 oz Au per ton, and as much as 0.61 % Cu, 72.8% Pb, and 2.6% Zn. ? In 1929, Buddington (1929, p. 102-108) described quartz veins in quartz diorite of the Texas Creek Granodiorite and in the metagraywacke and tuff in the roof of the pluton. The veins in the pluton generally are leaner in metallic minerals than those in the overlying bedded rocks. The veins carry galena, pyrite, chalcopyrite, sphalerite, pyrrhotite, and tetrahedrite. Gangue minerals include quartz, barite, calcite, and chlorite. Free gold was found in a piece of quartz(?) float from an unknown source.? Lead-isotope studies of galena from the Hyder Lead 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 Hyder Lead 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 = Early workings included surface stripping and opencuts.? Early assays showed 3.6-16.9 oz Ag and a trace to 0.18 oz Au per ton, and as much as 0.61 % Cu, 72.8% Pb, and 2.6% Zn.

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Mineral Resources Data System MRDS A010307
USGS Alaska Resource Data File ARDF BC037

Bibliographic references

  • Deposit

    Buddington, A.F., 1925, Mineral investigations in southeastern Alasaka: U.S. Geological Survey Bulletin 773, p. 71-139.

  • 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

    Cobb, E.H., 1978, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Bradfield Canal quadrangle, Alaska: U.S. Geological Survey Open-File Report 78-922, 98 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.

Comments on the references

  • Primary Reference = Cobb, 1978 (OFR 78-922)

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