Minntac Mine

Producer in St. Louis county in Minnesota, United States with commodity Iron

Geologic information

Identification information

Deposit ID 10072828
MRDS ID W018511
Record type Site
Current site name Minntac Mine
Alternate or previous names Pilotac Mine
Related records 10243455

Geographic coordinates

Geographic coordinates: -92.65464, 47.54471 (WGS84)
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Geographic areas

Country State County
United States Minnesota St. Louis

Public Land Survey System information

Meridian Township Range Section Fraction State
58N;59N 18W;18W 32,23;4,32,33,34 Minnesota

Comments on the location information

  • ALSO T58N,R18W,SEC1,4,5,6; T59N,R18W,SEC35

Commodities

Commodity Importance
Iron Primary

Materials information

Materials Type of material
Ankerite Ore
Magnetite Ore
Siderite Ore
Calcite Gangue
Chert Gangue

Alteration

  • (Local) Metamorphism In East Mesabi Range. French (1973) Identified Three Distinct Mineral Assembleges Related To Temperature And Pressure Conditions.

Host and associated rocks

  • Host or associated Host
    Rock type Sedimentary Rock > Chemical Sediment > Iron Formation
    Rock unit name Biwabik Iron Formation
    Stratigraphic age (youngest) Paleoproterozoic

Nearby scientific data

(1) -92.65464, 47.54471

Geologic structures

Type Description Terms
Regional Restricted Basin Required For Banded Iron Formation Deposition.
Local Faults

Ore body information

  • General form LINEAR
    Dip SOUTH: AT A LOW ANGLE
    Thickness 243.84M
    Length 321860M

Controls for ore emplacement

  • Inavailability Of Free Oxygen Allowing Ferrous Oxides To Form. Advent Of Photosynthetic Eucaryotic Organisms Releasing O2 2 B.Y. Ago Upset The Oxygen Poor Environment Required For Continued Ferrous Iron Deposition (Garrells, Et Al, 1973).

Economic information

Economic information about the deposit and operations

Development status Producer
Commodity type Metallic
Deposit size Large
Significant No

Mining district

District name Lake Superior Region, Mesabi District

Ownership information

  • Type Owner-Operator
    Owner U.S. Steel Corp.

Comments on development

  • 10/78 BEGAN PELLET PRODUCTION FROM STEP III EXPANSION AT MINNTAC PLANT. PROD. CAPACITY 18,000,000 TONS/YR. 11/78 SHIPPED ITS 100,000,000 TH GROSS TON IN 11 YEARS OF OPERATION.

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Mineral Resources Data System MRDS W018511

Bibliographic references

  • Deposit

    BAYLEY, R.W. AND JAMES, H.L., 1973, ECON. GEOL. V. 68, N. 7, PP. 934-1004.

  • Deposit

    FRENCH, B.V., 1973, ECON. GEOL. V.68, N. 7, PP. 1063-1074.

  • Deposit

    LA BERGE, G.L., 1973, ECON. GEOL., V. 68, N. 7, PP. 1098-1109.

  • Deposit

    GARRELS, R.M., PERRY, E.A., AND MACKENZIE, F.J., 1973, ECON. GEOL., VOL. 68, N. 7, PP. 1173-1179.

  • Production

    W. D. TRETHEWEY, MINING DIR. OF MINN. 1974, 1978, 1980.

General comments

Subject category Comment text
Deposit ECONOMIC GEOLOGY, 1973, V. 68, NO. 7, PP. 913-1179; ISSUE DEALS IN DETAIL WITH MANY ASPECTS OF WORLD PRECAMBRIAN BANDED IRON FORMATIONS.

Reporter information

Type Date Name Affiliation Comment
Reporter 01-JAN-1984 Schneider, Norma J. U.S. Geological Survey
Updater 01-NOV-1981 Schneider, Norma J. (Orris, Greta J.) U.S. Geological Survey
Editor 01-MAY-1997 Mason Jr., G.T. U.S. Geological Survey