Cornwall Mine

Past Producer in Lebanon county in Pennsylvania, United States with commodities Iron, Cobalt, Gold, Copper, Silver, Sulfur
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. Production statistics
  13. Reserves and resources
  14. Links to other databases
  15. Bibliographic references
  16. General comments
  17. Reporter information

Geologic information

Identification information

Deposit ID 10069387
MRDS ID W006887
Record type Site
Current site name Cornwall Mine
Alternate or previous names Cornwall East and Open Pit, Cornwall Iron-Cobalt Deposit

Geographic coordinates

Geographic coordinates: -76.40298, 40.26945 (WGS84)
Location accuracy 10000(meters)

Site location context

Political divisions (FIPS codes)

Lebanon(county)

Pennsylvania(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Lebanon(quadrangle 1:24,000 scale)

Harrisburg(quadrangle 1:100,000 scale)

Harrisburg(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Lower Susquehanna(hydrologic unit)

Lower Susquehanna(hydrologic accounting unit)

Susquehanna(hydrologic subregion)

Mid Atlantic(hydrologic region)

Geographic areas

Country State County
United States Pennsylvania Lebanon

Commodities

Commodity Importance
Iron Primary
Cobalt Critical Primary
Gold Secondary
Copper Secondary
Silver Secondary
Sulfur Secondary

Materials information

Materials Type of material
Magnetite Ore
Pyrite Ore
Chalcopyrite Ore
Diopside Gangue
Phlogopite Gangue
Garnet Gangue
Actinolite Gangue
Chlorite Gangue
Talc Gangue
Serpentine Gangue

Alteration

  • (Local) Potassium Metasomatism

Mineral occurrence model information

Model code 62
USGS model code 18d
Deposit model name Skarn Fe

Host and associated rocks

  • Host or associated Host
    Rock type Sedimentary Rock > Carbonate
    Rock unit name Buffalo Springs Formation
    Rock description Buffalo Springs Formation
    Stratigraphic age (youngest) Middle Cambrian
  • Host or associated Associated
    Rock type Metamorphic Rock > Hornfels
    Rock unit name Mill Hill Slate
    Rock description Mill Hill Slate
    Stratigraphic age (youngest) Late Ordovician
  • Host or associated Associated
    Rock type Metamorphic Rock > Hornfels
    Rock unit name Blue Conglomerate
    Rock description Blue Conglomerate
    Stratigraphic age (youngest) Late Ordovician
  • Host or associated Associated
    Rock type Plutonic Rock > Mafic Intrusive Rock > Diorite > Diabase
    Rock unit name York Haven Diabase Sheet
    Rock description York Haven Diabase Sheet
    Stratigraphic age (youngest) Jurassic

Nearby scientific data

(1) -76.40298, 40.26945

Economic information

Comments on the geologic information

  • Skarn-type magnetite deposits replace limestone, dolomite, and marble adjacent to the York Haven diabase sheet. Depositional temperatures are estimated at 400 - 500 degrees C, based on phase stability. Ore fluid speculated to be a sedimentary brine heated locally in sediments along the diabase contact. Metals are believed to have been acquired from both the diabase and Triassic sediments (Rose and Smith, 2001).

Economic information about the deposit and operations

Development status Past Producer
Commodity type Both
Significant Yes

Production statistics

  • Year 1962
    Material cobalt ore
    Ore mined 900mt
    Importance Item Commodity Group Amount recovered Grade Recovery percentage
    Major Ore Cobalt Cobalt 0wt-pct
  • Year 1962
    Material iron ore
    Ore mined 50000mt
  • Year 1972
    Period 1742-1972
    Material cobalt ore
    Ore mined 100000mt
  • Year 1973
    Period 1742-1973
    Material iron ore
    Ore mined 106000000mt

Comments on the production information

  • The deposit at Cornwall produced 106,000,000 tons of ore containing about 40% Fe, 0.3% Cu, 1.3% S, 0.001 oz/T Au, and pyrite with 1.4% Co.
  • Cobalt first produced commercially in 1941. Bethlehem Cornwall Corporation reports 400,000 to 600,000 pounds (or 273 MT) cobalt produced as a byproduct of mining magnetite (Vhays et al., 1973). Annual production grade in 1966 was 0.056% Co.

Reserves and resources

  • Type In-situ
    Estimate year 1962
    Reserves 45350mt commodity
    Commodity Subtype Grade units Group Importance Year
    Cobalt cobalt-iron ore 0.056 wt-pct Cobalt Major 1962

Reference information

Comments on the other database information

  • Old records were combined and new production and geology information added by Editor.

Bibliographic references

  • Deposit

    BILBREY, J. H., 1962, COBALT, A MATERIALS SURVEY: U.S. BUREAU OF MINES INFORMATION CIRCULAR 8130, P. 2, 26 AND 27.

  • Deposit

    VHAY, J.S., BROBST, DONALD A., AND HEYL, A. V., 1973, COBALT: (CHAPTER IN) U.S. MINERAL RESOURCES, U.S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 820, P. 145.

  • Deposit

    LAPHAM, D.M., 1968, TRIASSIC MAGNETITE AND DIABASE AT CORNWALL, PENNSYLVANIA: IN RIDGE, J.D., ED., ORE DEPOSITS OF THE UNITED STATES 1933-1967 (GRATON-SALES VOLUME) V. 1: AMERICAN INSTITUTE OF MINING, METALLURGICAL AND PETROLEUM ENGINEERS, P. 72-94.

  • Geology

    GRAY, C., GEYER, A.R., AND MCLAUGHLIN, D.B., 1958, RICHLAND QUADRANGLE: PENNSYLVANIA GEOLOGICAL SURVEY, 4TH SERIES, GEOLOGICAL ATLAS OF PENNSYLVANIA, ATLAS 167D, 1:24,000.

  • Deposit

    ROSE, A.W. AND SMITH, R.C., II, 2001, MAGNETITE-CU SKARNS FORMED BY NON-MAGMATIC (?) FLUIDS AT CORNWALL, PA AND VICINITY [ABSTRACT]: GEOLOGICAL SOCIETY OF AMERICA ANNUAL MEETING; PAPER NO. 2-O.

General comments

Subject category Comment text
Deposit COBALT FIRST PRODUCED COMMERCIALLY IN 1941. BETHLEHEM CORNWALL CORP., REF. 2 REPORTS 400,000 TO 600,000 POUNDS (OR 273 M.T.) COBALT PRODUCED AS BYPRODUCT OF MINING MAGNETITE. ; INFO.SRC : 1 PUB LIT

Reporter information

Type Date Name Affiliation Comment
Reporter 01-JAN-1975 Shaffer, Glenn L. U.S. Geological Survey
Reporter 01-JAN-1983 Whitlow, S. U.S. Geological Survey
Editor 07-NOV-2003 Woodruff, Laurel G. U.S. Geological Survey Work done in Filemaker

Beyond USGS

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