Jumbo

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

Geologic information

Identification information

Deposit ID 10000166
MRDS ID A010201
Record type Site
Current site name Jumbo
Alternate or previous names Marmot, lower basin
Related records 10282630

Geographic coordinates

Geographic coordinates: -130.35176, 56.01866 (WGS84)
Relative position The approximate location of the Jumbo prospect is in Section 36 on the southeast flank of Banded Mountain just above Through Glacier at an elevation of about 3400 feet (Elliott and Koch, 1981, p. 10, loc. 21). The location is probably accurate to within about a quarter of a mile.? Also see Additional Comments field, below.
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Geographic areas

Country State
United States Alaska

Commodities

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

Materials information

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

Alteration

  • (Local) Local intense iron staining of veins and country rocks.

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 Sedimentary Rock > Clastic Sedimentary Rock > Argillite
    Rock unit name Hazelton Group;Hazelton Group;
    Rock description Hazelton Group;Hazelton Group;
    Stratigraphic age (youngest) Late Jurassic
    Stratigraphic age (youngest) Late Jurassic
  • Host or associated Host
    Rock type Sedimentary Rock > Clastic Sedimentary Rock > Siltstone
    Rock unit name Hazelton Group
    Rock description Hazelton Group

Nearby scientific data

(1) -130.35176, 56.01866

Comments on the geologic information

  • Geologic Description = The country rocks in the area of this prospect are metamorphosed pelitic strata of the Jurassic or older Mesozoic Hazelton Group, which are underlain and locally intruded by the Triassic Texas Creek Granodiorite; and the Eocene Hyder Quartz Monzonite, which intrudes the Hazelton and Texas Creek rocks (Berg and others, 1977, p. 15-17; Koch, 1996). ? the deposit (Buddington, 1929, p. 101) consists of quartz fissure veins up to about 2 feet thick that cut metagraywacke, argillite, and banded hornfels and contain pyrite, galena, molybdenite, and traces of chalcopyrite and sphalerite. A field investigation in 1972 by the U.S. Bureau of Mines did not locate the Jumbo prospect or find the Jumbo adit reportedly driven sometime after Buddington's work (1929). Samples of quartz veins, breccia zones, and iron-stained, locally sulfide-bearing country rocks collected in 1972 in the general area of the Jumbo prospect (Berg and others, 1977, p. 101-110) contained up to 200 ppm Ag, 6% Pb, 8% Zn, and more than 2000 ppm Mo, but the average values of these metals was much lower. The veins also contain minor Cu, Zn, and Au.? Lead-isotope studies of the galena at the Marmot lower basin prospect (Maas, 1995, p. 229-248) indicate that the deposit is Eocene in age, and contemporaneous with emplacement of the Hyder Quartz Monzonite.
  • Age = Lead-isotope studies of the galena at the Marmot lower basin prospect (Maas, 1995, p. 229-248) indicate that the deposit is Eocene in age, and 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 = An adit is said to have been driven sometime after 1929.? Samples collected in 1972 by U. S. Bureau of Mines contained up to 200 ppm Ag, 6% Pb, 8% Zn, and more than 2000 ppm Mo, but the average values of these metals was much lower.

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Mineral Resources Data System MRDS A010201
USGS Alaska Resource Data File ARDF BC021

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

    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 Jumbo prospect on Banded Mountain (Buddington, 1929, p. 101) was originally staked in 1925 with 2 claims, restaked as a 6-claim group in 1933, 1935, and 1941, and covered in 1969 by the Marmot group of 51 claims (Berg and others, 1977, p. 40-41, 100-114). This record covers the area described as 'Marmot, lower basin (Jumbo area)' in Berg and others (1977, p. 101-106).? 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