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Isle Royale Amygdaloid

Past Producer in Houghton county in Michigan, United States with commodities Copper, Silver
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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. Alteration
  9. Mineral occurrence model information
  10. Host and associated rocks
  11. Nearby scientific data
  12. Geologic structures
  13. Ore body information
  14. Economic information about the deposit and operations
  15. Mining district
  16. Ownership information
  17. Production statistics
  18. Bibliographic references
  19. General comments
  20. Reporter information

Geologic information

Identification information

Deposit ID 10082608
MRDS ID W060041
Record type Site
Current site name Isle Royale Amygdaloid
Alternate or previous names Grand Portage Amygdaloid Lode, Isle Royale Lode, Isle Royale Amygdaloid Lode

Comments on the site names

  • ISLE ROYALE AMYGDALOID HAS SEVERAL NAMES: BETWEEN NO. 7 SHAFT AND NO. 1 SHAFT OF ISLE ROYALE MINE, IT IS CALLED THE ISLE ROYALE LODE. NORTH OF THE NO. 1 SHAFT IT IS CALLED THE GRAND PORTAGE LODE. IT ALSO MAY BE CORRELATIVE WITH THE ARCADIAN LODE NORTH OF PORTAGE LAKE

Geographic coordinates

Geographic coordinates: -88.58033, 47.09778 (WGS84)
Relative position Isle Royale Mine location

Site location context

Political divisions (FIPS codes)

Houghton(county)

Michigan(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Chassell(quadrangle 1:24,000 scale)

Hancock(quadrangle 1:100,000 scale)

Hancock C(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Keweenaw Peninsula(hydrologic unit)

Southcentral Lake Superior(hydrologic accounting unit)

Southern Lake Superior(hydrologic subregion)

Great Lakes(hydrologic region)

Geographic areas

Country State County
United States Michigan Houghton

Public Land Survey System information

Meridian Township Range Section Fraction State
Michigan 055N 034W 36 SE 4 OF SW 4 Michigan

Comments on the location information

  • LOCATION TAKEN AS THE POSITION OF THE NO. 1 SHAFT OF THE ISLE ROYALE MINE

Commodities

Commodity Importance
Copper Primary
Silver Secondary

Materials information

Materials Type of material
Copper Ore
Silver Ore
Epidote Gangue
Pumpellyite-(Mg) Gangue
Quartz Gangue
Sericite Gangue
Calcite Gangue
Datolite Gangue
Laumontite Gangue
Chalcocite Gangue
Domeykite Gangue

Alteration

  • (Local) Early oxidation followed by epidotization/pumpellitization associated with mineralization

Mineral occurrence model information

Model code 96
USGS model code Unassigned
Deposit model name Native Cu
Mark3 model number 99

Host and associated rocks

  • Host or associated Host
    Rock type Volcanic Rock (Aphanitic) > Mafic Volcanic Rock > Basalt
    Rock unit name Portage Lake Volcanics
    Rock description Portage Lake Volcanics
    Stratigraphic age (youngest) Stenian
    Chronological age 1095

Nearby scientific data

(1) -88.58033, 47.09778
ListMap

Economic information

Geologic structures

Type of structure Local
Structure description Isle Royale syncline and Grand Portage fault

Ore body information

  • Name ISLE ROYALE AMYGDALOID
    General form AMYGDALOIDAL LODE

Comments on the geologic information

  • THE ISLE ROYALE AMYGDALOID ISA COARSELY FRACTURED AMYGDALOIDAL BASALT FLOW WITH A THICK FLOWTOP BRECCIA. THE FLOW TOPS ARE HEAVILY OXIDIZED AND RANGE IN COLOR FROM VARIOUS SHADES OF GRAY TO BRICK RED. MINERALIZED ROCKS ARE GREENISH GRAY OR BLACK TO BROWN OR GRAY (WILSON AND DYL, 1992).

Economic information about the deposit and operations

Operation type Underground
Development status Past Producer
Commodity type Metallic
Deposit size Large
Significant Yes
Year of first production 1852
Year of last production 1968

Mining district

District name Keweenaw Copper

Ownership information

  • Type Operator
    Owner Isle Royale Copper Company (Consolidation of Old Isle Royale Company, Huron Company, Grand Portage C

Production statistics

  • Year 1968
    Period 1855-1968
    Accuracy Accurate
    Importance Item Commodity Group Amount recovered Grade Recovery percentage
    Major recovered Cu Copper Copper 154635.7mt

Comments on the production information

  • Ore graded 0.9% Cu.

Comments on the workings information

  • SHAFTS ANGLED TO LODE WITH ADIT LEVELS FOR DRAINAGE, STOPING OCCURRED CLOSE TO THE OUTCROP IN THE ISLE ROYALE LODE, AND ALTHOUGH A LARGER PERCENTAGE OF THE LODE HAS PROBABLY BEEN MINED AFTER THE LOWER LEVELS RATHER THAN THE HIGHER LEVELS, THAT FACT IS APPARENTLY A RESULT OF CHANGE OF MINING METHODS THAN OF DIFFERENCE OF THE CHARACTER OF THE LODE.

Comments on development

  • OHIO AND ISLE ROYALE MINING COMPANY DISCOVERED THE ISLE ROYALE LODE. PORTAGE MINING CO. (1852) BECAME GRAND PORTAGE MINING CO IN 1860, IN 1901 BECAME CONSOLIDATED WITH ISLE ROYALE COPPER CO. AND THEY MINED DOWN DIP BENEATH THE OHIO AND ISLE ROYALE MINING COMPANY DISCOVERED THE ISLE ROYALE LODE. PORTAGE MINING CO. (1852) BECAME GRAND PORTAGE MINING CO IN 1860, IN 1901 BECAME CONSOLIDATED WITH ISLE ROYALE COPPER CO. AND THEY MINED DOWN DIP BENEATH THE OLD WORKINGS. THE ISLE ROYALE COPPER COMPANY HAD 7 SHAFTS ON THE ISLE ROYALE AMYGDALOID, PLUS 7 OLDER SHAFTS AND 1 SHAFT ON THE BALTIC LODE. THE SHELDEN MINING COMPANY FORMED TO MINE THE GRAND PORTAGE (ISLE ROYALE) LODE, LATER COMBINED WITH THE COLOMBIAN MINING COMPANY IN 1864.

Reference information

Bibliographic references

  • Deposit

    BUTLER, B.S., AND BURBANK, W.S., 1929, THE COPPER DEPOSITS OF MICHIGAN: USGS PROF. PAPER NO. 144, 238 PP.

  • Deposit

    WEEGE, R.J., AND POLLACK, J.P., 1971, RECENT DEVELOPMENTS IN THE NATIVE COPPER DISTRICT OF MICHIGAN: IN W.S. WHITE, (EDITOR), GUIDEBOOK FOR FIELD CONFERENCE, MICHIGAN COPPER DISTRICT; SEPT. 30-OCT. 2, 1971, SOC. ECON. GEOL., P. 19-43

  • Deposit

    WHITE, W.S., 1968, THE NATIVE COPPER DEPOSITS OF NORTHERN MICHIGAN: IN J.D. RIDGE, (EDITOR) ORE DEPOSITS OF THE UNITED STATES 1933-1967, (GRATON-SALES VOL); AM. INSTIT. MIN. METALL. PETROL. ENG., V. 1, P. 303-325

  • Deposit

    WHITE, W.S., 1956, GEOLOGIC MAP OF THE CHASSELL QUADRANGLE, MICHIGAN: USGS MAP MF-43, SCALE 1:24000.

  • Deposit

    BODWELL, W.A., 1972, GEOLOGIC COMPILATION AND NONFERROUS METAL POTENTIAL, PRECAMBRIAN SECTION, NORTHERN MICHIGAN: HOUGHTON, MICHIGAN TECHNOLOGICAL UNIVERSITY, M.S. THESIS, 98 P.

  • Deposit

    BORNHORST, THEODORE J., 1992, KEWEENAWAN COPPER DEPOSITS OF WESTERN UPPER MICHIGAN; AN OVERVIEW OF THE KEWEENAW PENINSULA NATIVE COPPER DISTRICT, MICHIGAN: GUIDEBOOK SERIES, VOL. 13, P. 33-62.

  • Deposit

    WILBAND, J.T, 1978, THE COPPER RESOURCES OF NORTHERN MICHIGAN, USBM - J0366067.

  • Deposit

    WILSON, M. L. AND DYL, S.J., II, 1992, MICHIGAN COPPER COUNTRY; MINERALOGICAL RECORD, V. 23, P. 29-41.

  • Deposit

    JOHNSON, A.M. AND GROTH, E.H., 1998, INVENTORY OF UNDERGROUND MINES, HOUGHTON COUNTY, SITE ID 310029, MICHIGAN DEPARTMENT OF NATURAL RESOURCES.

  • Production

    WEEGE AND POLLACK, 1971 WHITE, 1968

General comments

Subject category Comment text
Deposit ABUNDANT FISSURES. THREE LODES WERE DEVELOPED: GRAND PORTAGE AMYGDALOID "WEST LODE", THE "SO CALLED" ISLE ROYALE AMYGDALOID (FAULT DISPLACED) OR THE "EAST LODE" & "ISLE ROYALE AMYGDALOID" PROPER

Reporter information

Type Date Name Affiliation Comment
Reporter 01-JUL-95 Nicholson, Suzanne U.S. Geological Survey
Updater 01-MAR-97 Sutphin, D.M. U.S. Geological Survey
Editor 01-MAY-97 Mason Jr., G.T. U.S. Geological Survey
Editor 04-AUG-02 Anderson, Arlene (M. Gere) Michigan Department of Natural Resources
Editor 07-JAN-11 Nicholson, S.W. U.S. Geological Survey Moved location to site of Isle Royale Mine (from NAD27 47.11667, -88.5625). Did not change PLSS data (which thus reflects original [incorrect] entry)

Beyond USGS

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

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