Atoll

Prospect in Alaska, United States with commodities Zinc, Lead
Sections on this page
  1. Identification information
  2. Geographic coordinates
  3. Site location context
  4. Geographic areas
  5. Commodities
  6. Materials information
  7. Alteration
  8. Mineral occurrence model information
  9. Host and associated rocks
  10. Nearby scientific data
  11. Economic information about the deposit and operations
  12. Mining district
  13. Links to other databases
  14. Bibliographic references
  15. General comments
  16. Reporter information

Geologic information

Identification information

Deposit ID 10307797
Record type Site
Current site name Atoll

Geographic coordinates

Geographic coordinates: -154.36996, 63.41649 (WGS84)
Relative position The Atoll prospect is situated at about 2,000 feet in elevation on the northwest slope of a ridge approximately 2.5 miles (4 km) northwest of Reef Ridge, in Section 11, T. 24 S., R. 23 E., of the Kateel River Meridian. Location is precisely known to within 100 feet (30 m).

Site location context

Political divisions (FIPS codes)

Yukon-Koyukuk(Census area)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Medfra B-3(quadrangle 1:63,360 scale)

Medfra S(quadrangle 1:100,000 scale)

Medfra C(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

North Fork Kuskokwim River(hydrologic unit)

Upper Kuskokwim River(hydrologic accounting unit)

Southwest(hydrologic subregion)

Alaska(hydrologic region)

Federal lands

Doyon, Limited(ANCSA Region)

ANCSA Region NTVPIC(Type of land area)

NTVPIC(Federal land areas administered by NTVPIC)

Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Zinc Critical Primary
Lead Secondary

Comments on the commodity information

  • Gangue = ferricrete minerals

Materials information

Materials Type of material
Smithsonite Ore
Dolomite Gangue

Alteration

  • (Local) Secondary dolomite.

Mineral occurrence model information

Model code 224
USGS model code 32a
Deposit model name Mississippi Valley, S.E. Missouri Pb-Zn
Mark3 model number 42

Host and associated rocks

  • Host or associated Host
    Rock type
    Stratigraphic age (youngest) Late Ordovician

Nearby scientific data

(1) -154.36996, 63.41649

Economic information

Comments on the geologic information

  • Geologic Description = At the Atoll prospect, smithsonite-bearing, iron-oxide gossan covers an area of 300 feet by 50 feet (91 m by 15 m) in tectonized dolomite and micritic limestone; unit probably equivalent to the Paradise Fork Formation of Dutro and Patton (1982). Mineralized rubble constitutes about one percent of float on the hillslope. Host unit is Late-Ordovician based on fossils (Dutro and Patton, 1982). Age of mineralization is not known. . A large composite, chip-channel sample of 50 samples taken across the mineralized zone averaged 1.0 percent zinc and 395 ppm lead. A high-graded sample of 10 pieces of mineralized float contained 7.95 percent zinc but no lead. A strong zinc soil anomaly (1,900 to 4,000 ppm) covers a 1,000 feet by 4,000 feet (300 m by 122 m) area below the Atoll prospect (Andrews and Rishel, 1982).
  • Age = Host unit is Late-Ordovician based on fossils (Dutro and Patton, 1982). Age of mineralization is not known.

Economic information about the deposit and operations

Development status Prospect

Comments on exploration

  • Status = Inactive

Mining district

District name McGrath

Comments on the workings information

  • Workings / Exploration = The Atoll prospect was discovered by WGM Inc. and Patino Ltd. during exploration for base metals in the late 1970s on lands selected by Doyon Ltd. (Andrews and Rishel, 1982). A large composite, chip-channel sample of 50 samples taken across the mineralized zone averaged 1.0 percent zinc and 395 ppm lead. A high-graded sample of 10 pieces of mineralized float yielded 7.95 percent zinc but no lead. A strong zinc soil anomaly (1,900 to 4,000 ppm) covers a 1,000 feet by 4,00 feet (300 m by 122 m) area below the Atoll prospect.

Reference information

Bibliographic references

  • Deposit

    Patton, W.W., Jr., Moll, E.J., Dutro, J.T., Jr., Silberman, M.L., and Chapman, R.M., 1980, Preliminary geologic map of Medfra quadrangle, Alaska: U.S. Geological Survey Open-File Report 80-811-A, 1 sheet, scale l:250,000.

  • Deposit

    Andrews, Tom, and Rishel, John, 1982, Annual Report for 198, Reef Ridge I-to-XIII Project Areas, Kuskokwim Block, Alaska: Anchorage, Alaska, WGM Inc., Project Report 4, 45 pages, two sheets at 1:63,360 and 1:20,000 scales. (Report held by Doyon, Limited, Fairbanks, Alaska.)

  • Deposit

    Dutro, T.T. Jr., and Patton,W.W. Jr., 1982, New Paleozoic Formations in the northern Kuskokwim Mountains, west-central Alaska: U.S. Geological Survey Bulletin 1529-H, p. H13-H22.

  • Deposit

    Schmidt, J.M., 1997, Shale-hosted Zn-Pb-Ag and barite deposits of Alaska, in Goldfarb, R.J., and Miller, L.D., eds., Mineral Deposits of Alaska, 1997: Economic Geology Monograph 9, p. 35-65.

Comments on the references

  • Primary Reference = Andrews and Rishel, 1982

General comments

Subject category Comment text
Deposit Model Name = Southeast Missouri Pb-Zn, (Cox and Singer, 1986; model no. 32a)
Deposit Other Comments = See Reef Ridge (MD055), Midway (MD046), Beaver Creek (MD048) ,and other Mississippi Valley Type prospects in Medfra quadrangle. The Atoll prospect is on land selected or conveyed to Doyon Ltd. For further information, contact Doyon Ltd. at 210 1st Ave., Fairbanks, Alaska, 99701.

Reporter information

Type Date Name Affiliation Comment
Reporter 02-JUN-98 Bundtzen, T.K. Pacific Rim Geological Consulting

Beyond USGS

Supplemental information added by qvyshift.com. Not part of the original USGS MRDS record.

Authoritative Alaska resources

These are landing pages for further research — the state agencies don't currently expose per-mine deep links.