Gunflint Corridor East

Occurrence in Cook county in Minnesota, United States with commodities Nickel, Copper
Sections on this page
  1. Identification information
  2. Geographic coordinates
  3. Site location context
  4. Geographic areas
  5. Public Land Survey System information
  6. Commodities
  7. Materials information
  8. Mineral occurrence model information
  9. Host and associated rocks
  10. Nearby scientific data
  11. Geologic structures
  12. Ore body information
  13. Controls for ore emplacement
  14. Economic information about the deposit and operations
  15. Mining district
  16. Land status
  17. Ownership information
  18. Workings at the site
  19. Links to other databases
  20. Bibliographic references
  21. General comments
  22. Reporter information

Geologic information

Identification information

Deposit ID 10072945
MRDS ID W018676
Record type Site
Current site name Gunflint Corridor East

Geographic coordinates

Geographic coordinates: -90.74014, 48.08306 (WGS84)
Elevation 550
Relative position ALONG GUNFLINT TRAIL NEAR GUNFLINT AND LOON LAKES

Site location context

Political divisions (FIPS codes)

Cook(county)

Minnesota(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Gunflint Lake(quadrangle 1:24,000 scale)

Saganaga Lake(quadrangle 1:100,000 scale)

Quetico(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Rainy Headwaters(hydrologic unit)

Rainy(hydrologic accounting unit)

Rainy(hydrologic subregion)

Souris-Red-Rainy(hydrologic region)

Federal lands

Superior National Forest(National Forest)

National Forest FS(Type of land area)

FS(Federal land areas administered by FS)

Geographic areas

Country State County
United States Minnesota Cook

Public Land Survey System information

Meridian Township Range Section Fraction State
4th Principal 065N;065N 003W;004W 25,26 Minnesota

Commodities

Commodity Importance
Nickel Critical Tertiary
Copper Tertiary

Materials information

Materials Type of material
Bornite Ore
Chalcopyrite Ore
Biotite Gangue
Olivine Gangue
Plagioclase Gangue
Pyroxene Gangue
Pyrrhotite Gangue

Mineral occurrence model information

Model code 9
USGS model code 5a
Deposit model name Duluth Cu-Ni-PGE

Host and associated rocks

  • Host or associated Host
    Rock type Plutonic Rock > Mafic Intrusive Rock > Gabbro > Troctolite
    Rock unit name Poplar Lake Intrusion
    Stratigraphic age (youngest) Mesoproterozoic

Nearby scientific data

(1) -90.74014, 48.08306

Economic information

Geologic structures

Type of structure Regional
Structure name FAULTS RELATED TO EMPLACEMENT OF DULUTH COMPLEX

Ore body information

  • General form TABULAR
    Strike E00W
    Dip 44S
    Thickness 50M
    Length 4800M
    Depth to top 2M
    Depth to bottom 300M

Controls for ore emplacement

  • Sulfides Segregated In Basal Troctolites Sub-Parallel To Lower Contact.

Comments on the geologic information

  • ROVE AND GUNFLINT FM. OVERLIE SAGANAGA--INTRUDED BY LOGAN. SERIES DULUTH GABBROS EMPLACED IN RIFT-RELATED VOIDS AND GRABENS. TROCTOLITIC LAST INTRUSIONS FORM BASAL CONTACT

Economic information about the deposit and operations

Development status Occurrence
Commodity type Metallic
Deposit size Large
Significant No
Discovery year 1966
Discoverer Cleveland Cliffs Iron Co.

Mining district

District name Northern Margin Duluth Complex

Land status

Ownership category National Forest

Ownership information

  • Type Owner
    Owner Cleveland-Cliffs Iron Co. And Amerada Hess Corp.

Comments on the reserve resource information

  • ESTIMATES ARE THE 50: PROBABILITY LEVEL IN MINERALS AVAILABILITY SYSTEM (M.A.S. FILE, DEPT. OF NAT. RESC.) AND ARE BASED ON DRILL CORE DATA.

Workings at the site

  • Type of workings Surface
    Overall length 10515.6M
    Overall width 1600M

Comments on the workings information

  • AN OPEN-PIT MINING MODEL IS PROPOSED AS A BASIS FOR CALCULATIONS. MINING TO PROCEED TO A DEPTH OF 300 M. EXTENT OF MINERALIZATION DOWNDIP UNDETERMINED.

Comments on development

  • DEPOSITS DISCOVERED BY GEOLOGIC MAPPING AND LOCALIZED BY DRILLING. ; ECON.COM: ENVIRONMENTAL CONCERNS. SUBMARGINAL ORE AT PRESENT TIME

Reference information

Bibliographic references

  • Deposit

    JOHNSON, R. G., 1970, ECONOMIC GEOLOGY OF A PORTION OF THE DULUTH COMPLEX, UNIV. OF IOWA PHD THESIS.

  • Deposit

    WEIBLEN AND MOREY, 1975, THE DULUTH COMPLEX--AN INTEGRATED SUMMARY; PROC. A.I.M.E.

  • Deposit

    1969 GEOLMAP MINN GEOLOGICAL SURVEY OPEN FILE MA

General comments

Subject category Comment text
Deposit POSSIBLE; SULFIDES ORIGINATED AS INTERCUMULATE IN LITHIFYING TROCTOLITE WHEN SULFUR INTRODUCED (FROM CONTACT METAMORPHOSED OLDER ROCKS) TO LIQUID FRACTION CREATING IMMISCIBLE SULFIDE AND SILICATE LIQUIDS. HIGHER DENSITY OF SULFIDE AND BASAL INTRODUCTION OF SULFUR CREATED BASAL LOCALIZATION. VARIATION IN SULFUR SOURCE, PATHWAYS, AND FAULTING CREATED LOCAL VARIATION AND HIGHER HORIZONS

Reporter information

Type Date Name Affiliation Comment
Reporter 01-JAN-1984 Sutphin, David M. U.S. Geological Survey
Updater 01-MAR-1997 Sutphin, David M. U.S. Geological Survey
Editor 01-MAY-1997 Mason Jr., G.T. U.S. Geological Survey

Beyond USGS

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