Marmot, upper basin

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

Geologic information

Identification information

Deposit ID 10000163
MRDS ID A010199
Record type Site
Current site name Marmot, upper basin

Geographic coordinates

Geographic coordinates: -130.37065, 56.02588 (WGS84)
Relative position The Marmot upper basin prospect (Berg and others, 1977, p. 106) is in Section 26 on the southeast side of Banded Mountain at an elevation of about 4600 to 4750 feet. This location is accurate to within about a quarter of a mile.
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Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Silver Primary
Copper Primary
Molybdenum Primary
Lead Primary
Gold Secondary
Zinc Secondary

Materials information

Materials Type of material
Chalcopyrite Ore
Galena Ore
Molybdenite Ore
Pyrite Ore
Calcite Gangue
Quartz Gangue

Alteration

  • (Local) Local intense iron staining

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;Hyder Quartz Monzonite;Hazelton Group;Hazelton Group
    Rock description Texas Creek Granodiorite;Hyder Quartz Monzonite;Hazelton Group;Hazelton Group
    Stratigraphic age (youngest) Late Jurassic
    Stratigraphic age (youngest) Late Jurassic
  • Host or associated Host
    Rock type Metamorphic Rock > Hornfels
    Rock unit name Hazelton Group
    Rock description Hazelton Group

Nearby scientific data

(1) -130.37065, 56.02588

Comments on the geologic information

  • Geologic Description = The country rocks in the general area of this prospect (Berg and others, 1977, p. 15-18, 22; Koch, 1996) are banded variegated pelitic hornfels, phyllite, and fine-grained schist of the Jurassic or older Mesozoic Hazelton Group. The metasedimentary rocks are intruded by andesite dikes that may be apophyses of the Triassic Texas Creek Granodiorite, and by aplite dikes that may be apophyses of Eocene Hyder Quartz Monzonite. ? the mineral deposit (Berg and others, 1977, p. 100, 106, 110, 112; Elliott and Koch, 1981, p. 9, loc. 19) consists of a stockwork(?) of quartz [-calcite] veins up to about 3 feet thick in locally iron-stained dark pelitic hornfels of the Hazelton Group. The veins contain pyrite, chalcopyrite, molybdenite, and galena. The highest assay values reported from vein and hostrock samples collected by the U.S. Bureau of Mines in 1972 were 2000 ppm Mo, 5000 ppm Pb, 3000 ppm Cu, 150 ppm Ag, and 0.1 ppm Au.? Lead-isotope studies of the galena at the Marmot upper basin 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 the galena at the Marmot upper basin 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 = Highest assay values reported from veins and hostrock samples collected by U.S. Bureau of Mines in 1972 were 2000 ppm Mo, 5000 ppm Pb, 3000 ppm Cu, 150 ppm Ag, and 0.1 ppm Au.

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Mineral Resources Data System MRDS A010199
USGS Alaska Resource Data File ARDF BC019

Bibliographic references

  • Deposit

    Berg, H.C., Elliott, R.L., Smith, J.G., Pittman, T.L., and Kimball, A. L., 1977, Mineral resources of the Granite Fiords wilderness study area, Alaska, with a section on aeromagnetic data by Andrew Griscom: U.S. Geological Survey Bulletin 1403, 151 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 = Berg and others, 1977

General comments

Subject category Comment text
Deposit Model Name = Polymetallic veins
Deposit Other Comments = the Marmot group of 51 claims that were staked in 1969 covered all or parts of the old Jumbo (Banded Mountain) (BC021), Galena (BC022), and Edelweiss (BC023) prospects, which are described separately in this report. The Marmot upper basin prospect area was only recently exposed by retreat of glacial ice. The prospect was active in 1973. ? Site is in Misty Fiords National Monument.

Reporter information

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