Buck

Prospect in Alaska, United States with commodities Gold, Copper

Geologic information

Identification information

Deposit ID 10001601
MRDS ID A012363
Record type Site
Current site name Buck
Alternate or previous names North Paula

Geographic coordinates

Geographic coordinates: -131.73483, 55.19168 (WGS84)
Relative position The approximate location of the Buck prospect, as described in early reports (Wright and Wright, 1908, fig. 10; Elliott and others, 1978, loc. 117), apparently coincides with the location of the North Paula prospect, as described by Maas and others (1995, loc. 310). The map site is for the North Paula prospect, at an elevation of about 150-175 feet on the NE flank of Punch Hill (sec 17, T. 77 S., R. 91 E., of the Copper River Meridian). The location of the North Paula prospect is accurate within a hundred feet or so.
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Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Gold Primary
Copper Primary

Materials information

Materials Type of material
Chalcopyrite Ore
Pyrite Ore
Quartz Gangue

Alteration

  • (Local) Probably local silicification, carbonatization, pyritization, and introduction of hydrothermal hematite.

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 Host
    Rock type Metamorphic Rock > Metasedimentary Rock > Quartzite

Nearby scientific data

(1) -131.73483, 55.19168

Comments on the geologic information

  • Geologic Description = Southern Gravina Island is underlain by an assemblage of undivided Silurian or Ordovician metamorphosed bedded and intrusive rocks; a stock and associated dikes of Silurian trondhjemite that cuts the metamorphic assemblage; and a sequence of Upper Triassic carbonate, clastic, rhyolitic, and basaltic strata that unconformably overlies the older rocks (Berg, 1973, 1982; Berg and others, 1988). The rocks are complexly folded and are cut by high-angle faults and by low-angle thrust faults. In many places, the Triassic rhyolite and the rocks beneath it are permeated by microscopic particles of hydrothermal hematite, giving them a pink, purple, or red hue (Berg, 1973, p. 14).? Wright and Wright (1908, p. 139) describe the Buck prospect only as a wide quartz vein, in altered quartzite and schist, that reportedly assayed well in Cu and Au. Maas and others (1995, p. 229) describe the North Paula deposit as seams and clasts of chalcopyrite and pyrite in silicified breccia in metavolcanic hostrock. Their best sample assayed 1.1% Cu across a 6-foot-wide section of the deposit. Workings, probably mainly dating to the early 1900s, included a 12.5-foot adit, a flooded shaft, and several trenches. ? Maas and others (1995, p. 227) report that copper mineralization on southern Gravina Island generally is associated with faulting. The deposits are mainly in meta-andesite (greenschist) and trondhjemite, but also in the overlying Triassic strata. The deposits are chiefly chalcopyrite- and pyrite-bearing quartz fissure veins, but the sulfide minerals also occur as disseminations in the metavolcanic rocks, in silicified zones in the trondhjemite, and as clasts or pods in silicified or carbonatized breccia. The character and setting of the deposits suggest that they mainly are polymetallic veins of Late Triassic or younger age.
  • Age = Late Triassic or younger.

Economic information

Economic information about the deposit and operations

Development status Prospect
Commodity type Metallic

Mining district

District name Ketchikan

Comments on the workings information

  • Workings / Exploration = Workings, probably mainly dating to the early 1900s, included a 12.5-foot adit, a flooded shaft, and several trenches (Maas and others, 1995, p. 229). Maas and others' best sample assayed 1.1% Cu across a 6-foot-wide section of the deposit.

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Mineral Resources Data System MRDS A012363
USGS Alaska Resource Data File ARDF KC120

Bibliographic references

  • Deposit

    Wright, F.E., and Wright, C.W., 1908, The Ketchikan and Wrangell mining districts, Alaska: U.S. Geological Survey Bulletin 347, 210 p.

  • Deposit

    Berg, H.C., 1973, Geology of Gravina Island Alaska: U.S. Geological Survey Bulletin 1373, 41 p.

  • Deposit

    Elliott, R.L., Berg, H.C., and Karl, Susan, 1978, map and table describing metalliferous and selected nonmetalliferous mineral deposits, Ketchikan and Prince Rupert quadrangles, Alaska: U.S. Geological Survey Open-file Report, 78-73-B,17 p., scale 1:250,000.

  • Deposit

    Berg, H.C., 1982, The Alaska Mineral Resource Assessment Program; guide to information about the geology and mineral resources of the Ketchikan and Prince Rupert quadrangles, southeastern Alaska: U.S. Geological Survey Circular 855, 24 p.

  • Deposit

    Berg, H.C., Elliott, R.L., and Koch, R.D., 1988, Geologic map of the Ketchikan and Prince Rupert quadrangles, southeastern Alaska: U.S. Geological Survey Mineral Investigations Series Map MF-1807,27 p., scale 1:250,000.

  • 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 = Berg, 1973; Maas and others, 1995

General comments

Subject category Comment text
Deposit Model Name = Polymetallic veins (Cox and Singer, 1986; model 22c)

Reporter information

Type Date Name Affiliation Comment
Reporter 05-JUL-1999 H.C. Berg U.S. Geological Survey