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Kearsarge 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. Controls for ore emplacement
  14. Economic information about the deposit and operations
  15. Mining district
  16. Production statistics
  17. Bibliographic references
  18. General comments
  19. Reporter information

Geologic information

Identification information

Deposit ID 10082605
MRDS ID W060037
Record type Site
Current site name Kearsarge Amygdaloid
Alternate or previous names Kearsarge Lode, Kearsarge Amygdaloid Lode
Related records 10146467

Comments on the site names

  • THE KEARSARGE AMYGDALOID LODE WAS THE MOST PRODUCTIVE AMYGDALOID LODE IN THE DISTRICT. NUMEROUS MINES WORKED THE LODE, INCLUDING THE WOLVERINE, NORTH AND SOUTH KEARSARGE, MOHAWK, AHMEEK, ALLOUEZ, GRATIOT, LASALLE, SENECA, CENTENNIAL, CALUMET & HECLA (ON KEARSARGE), AND OJIBWAY.

Geographic coordinates

Geographic coordinates: -88.41755, 47.27778 (WGS84)

Site location context

Political divisions (FIPS codes)

Houghton(county)

Michigan(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Ahmeek(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
056N 032W 6 SE 4 OF SE 4 Michigan

Comments on the location information

  • LOCATION CENTERED ON SITE OF FIRST PRODUCTION (WHAT IS NOW THE NORTH KEARSARGE MINE [NO. 1 SHAFT] IN AHMEEK QUAD) AMYGDALOID FLOW HAS BEEN RECOGNIZED FOR STRIKE LENGTH OF 35 MILES (TOWN OF ATLANTIC TO TOWN OF MANDAN). LODE WAS MINED FOR STRIKE LENGTH OF AT LEAST 10 MILES (MOSTLY IN AHMEEK AND LAURIUM QUADS). LAT/LON IS FOR THE ORE BODY.

Commodities

Commodity Importance
Copper Primary
Silver Secondary

Comments on the commodity information

  • MANY EXCELLENT SILVER SPECIMENS WERE COLLECTED FROM MINES ON THE KEARSARGE AMYGDALOID. SILVER TYPICALLY IS ALSO MORE MASSIVE THAN SILVER FROM OTHER LODES. WHETHER THIS MEANS THAT SILVER WAS MORE ABUNDANT IN THE KEARSARGE IS UNKNOWN AS NO STATISTICS FOR SILVER ARE KNOWN, AS, BY TRADITION IN THE COPPER COUNTRY, THE COPPER BELONGED TO THE COMPANY BUT THE SILVER BELONGED TO THE MINERS, SO MOST SILVER WAS HIGH-GRADED.

Materials information

Materials Type of material
Copper Ore
Silver Ore
Epidote Gangue
Feldspar Gangue
Quartz Gangue
Calcite Gangue
Prehnite Gangue
Pumpellyite-(Mg) Gangue
Microcline Gangue
Arsenical Copper Gangue
Datolite Gangue

Alteration

  • (Local) Oxidized and bleached

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) -88.41755, 47.27778
ListMap

Economic information

Geologic structures

Type of structure Regional
Structure description Regional anticline
Type of structure Local
Structure description Cut by mass fissure and other fissures

Controls for ore emplacement

  • Amygdaloidal flow top

Comments on the geologic information

  • OPHITIC FLOW WITH PLAGIOCLASE PHENOCRYSTS IN UPPER PORTION (DISTINCTIVE) AND DIRECTLY OVERLYING THE WOLVERINE SANDSTONE. THE KEARSARGE AMYGDALOID LODE RANGES FROM ONE THICK FLOW TO A SERIES OF FIVE THINNER FLOWS. BASALT HAS A WELL-DEVELOPED OPHITIC CHARACTER AND CONTAINS PLAGIOCLASE PHENOCRYSTS IN THE UPPER PART OF MAIN FLOW (WHICH MAKES IT DISTINCTIVE AND EASY TO TRACE). PLAGIOCLASE PHENOCRYSTS ARE MOST ABUNDANT JUST BELOW THE AMYGDALOIDAL FLOW TOP, THOUGH THEY ARE PRESENT IN THE INTERIOR OF THE FLOW. PLAGIOCLASE MAY BE AS LARGE AS AN INCH IN LENGTH, AND VERY ABUNDANT. THE CONCENTRATION OF PHENOCRYSTS AT THE BASE OF THE AMYGDALOID MAY BE THE RESULT OF THE CRYSTALS FLOATING THROUGH THE MOLTEN LAVA UNTIL THEY PONDED AGAINST THE SOLID, COOLING FLOW TOP. IN THE PRINCIPAL PRODUCTIVE AREA OF THE LODE, FROM THE CENTENNIAL MINE TO THE GRATIOT MINE, THE AMYGDALOID OF THE LOWEST FLOW OF THE SERIES HAS BEEN MINED, AND ONLY LOCALLY HAVE AMYGDALOIDS OF THE 'WEST LODES' BEEN SHOWN TO CONTAIN COPPER IN QUANTITY. IN THIS AREA THE FLOWS ARE THIN, AND PHENOCRYSTS ARE FEW.

Economic information about the deposit and operations

Operation type Underground
Development status Past Producer
Commodity type Metallic
Deposit size Large
Significant No
Discovery year 1887
Year of first production 1887
Production years AT LEAST THROUGH 1925

Mining district

District name Keweenaw Copper

Production statistics

  • Year 1967
    Period 1887-1967
    Accuracy Accurate
    Importance Item Commodity Group Amount recovered Grade Recovery percentage
    Major recovered Cu Copper Copper 1026496.6mt

Comments on the production information

  • Ore graded 1.05 % Cu.

Reference information

Bibliographic references

  • Deposit

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

  • 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 VOLUME): AM. INSTIT. MIN. METALL. PETROL. ENG., VOL. 1, 303-325.

  • Deposit

    DAVIDSON, E.S, ESPENSHADE, G.H., WHITE, W.S., AND WRIGHT, J.C., 1955, BEDROCK GEOLOGY OF THE MOHAWK QUADRANGLE, MICHIGAN: USGS MAP GQ-54, SCALE 1:24000

  • Deposit

    WHITE, W.S., CORNWALL, H.R., AND SWANSON, R.W., 1953, BEDROCK GEOLOGY OF THE AHMEEK QUADRANGLE, MICHIGAN: USGS MAP GQ-27, SCALE 1:24000

  • Deposit

    CORNWALL, H.R., AND WRIGHT, J.C., 1956, GEOLOGIC MAP OF THE HANCOCK QUADRANGLE, MICHIGAN: USGS MAP MF-46, 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

    CORNWALL, H.R., AND WRIGHT, J.C., 1956, GEOLOGIC MAP OF THE LAURIUM QUADRANGLE, MICHIGAN: USGS MAP MF-47, SCALE 1:24000

  • 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., PP. 19-43

  • Production

    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., PP. 19-43

General comments

Subject category Comment text
Deposit KEARSARGE WAS ONE OF THE RICHEST LODES - ESPECIALLY NEAR HANGING WALL. LODE AVERAGES 6-13 FEET THICK IN AREA OF MINING ACTIVITY
Deposit AMYGDALOIDAL BASALT (LOCALLY PORPHYRITIC)

Reporter information

Type Date Name Affiliation Comment
Reporter 01-JUL-1995 Nicholson, Suzanne U.S. Geological Survey
Updater 01-MAR-1997 Sutphin, D.M. U.S. Geological Survey
Editor 01-MAY-1997 Mason Jr., G.T. U.S. Geological Survey
Editor 02-APR-2004 Woodruff, Laurel U.S. Geological Survey
Editor 14-SEP-2009 Nicholson, Suzanne U.S. Geological Survey corrected typos

Beyond USGS

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

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