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Mahopac Magnetite Mine

Past Producer in Putnam county in New York, United States with commodity Iron
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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. Host and associated rocks
  9. Nearby scientific data
  10. Geologic structures
  11. Ore body information
  12. Controls for ore emplacement
  13. Economic information about the deposit and operations
  14. Mining district
  15. Ownership information
  16. Production statistics
  17. Workings at the site
  18. Links to other databases
  19. Bibliographic references
  20. General comments
  21. Reporter information

Geologic information

Identification information

Deposit ID 10067393
MRDS ID W000138
Record type Site
Current site name Mahopac Magnetite Mine
Alternate or previous names German Flats Mine
Related records 10151038

Geographic coordinates

Geographic coordinates: -73.75039, 41.3961 (WGS84)
Elevation 212
Relative position TWO MILES NORTHEAST OF WEST MAHOPAC; 4.3 MILES EAST OF OSCAWANA LAKE

Site location context

Political divisions (FIPS codes)

Putnam(county)

New York(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Oscawana Lake(quadrangle 1:24,000 scale)

Bridgeport(quadrangle 1:100,000 scale)

Hartford(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Lower Hudson(hydrologic unit)

Lower Hudson(hydrologic accounting unit)

Lower Hudson-Long Island(hydrologic subregion)

Mid Atlantic(hydrologic region)

Geographic areas

Country State County
United States New York Putnam

Commodities

Commodity Importance
Iron Primary

Comments on the commodity information

  • FOUR ORE BEDS WITHIN WIDTH OF 90 FEET; STRIKE N 18 DEG. E, DIP 40 DEG. ESE ORE BEDS IRREGULAR, VARY IN THICKNESS, COALESCE IN PLACES TO ONE ORE BED: ORE BED TRACED 1200 FEET IN LENGTH; WORKINGS 450 FEET LONG, 490 FEET DEEP. MEDIUM FINE-GRAINED ORE; EACH ORE BED 10 TO 50 FEET WIDE; NON ORE BEDS USED AS PILLARS AND SUPPORTS; STRIKE AND DIP QUICKLY CHANGEABLE.

Materials information

Materials Type of material
Magnetite Ore
Chondrodite Gangue
Mica Gangue
Serpentine Gangue

Alteration

  • (Local) Metamorphism Of Beds

Host and associated rocks

  • Host or associated Host
    Rock type Metamorphic Rock > Gneiss
    Rock unit name Paragneiss
    Rock description Paragneiss
    Stratigraphic age (youngest) Neoproterozoic
    Stratigraphic age (youngest) Neoproterozoic
    Stratigraphic age (youngest) Neoproterozoic

Nearby scientific data

(1) -73.75039, 41.3961
ListMap

Economic information

Geologic structures

Type of structure Regional
Structure description Folded, Faulted Uplands ; Reg.Trends: Northeast
Type of structure Local
Structure description Faulted Block

Ore body information

  • General form BLANKET
    Strike N 18 DEG. E
    Dip 40 DEG. ESE
    Thickness 149.35M
    Length 365.76M
    Width 27.43M
    Depth to top 0M
    Depth to bottom 149.35M

Controls for ore emplacement

  • Iron Rich Precambrian Bed

Comments on the geologic information

  • METAMORPHISM OF BEDS WITH MAGNETITE ; MAJOR.UNITS: PARAGNEISS AND PEGMATITE ; GEOL.DESC: HIGHLY METAMORPHOSED AND FAULTED AREA; COMPLEX GEOLOGY; NUMEROUS THEORIES; ORE CHARACTERISTICS SIMILAR TO ORE OF TILLY FOSTER MINE, HARTFORD 2 DEG. SHEET NO. 21. ; REG.COM: FAULTED METAMORPHOSED BEDS

Economic information about the deposit and operations

Development status Past Producer
Commodity type Metallic
Significant No
Discovery year 1825
Discoverer Prospector
Year of first production 1879

Mining district

District name Southeast New York

Ownership information

  • Type Owner-Operator
    Owner Mehopac Iron Ore Co.

Production statistics

  • Year 1895
    Period 1879 - 1895
    Material ORE FE
    Accuracy Estimate
    Description Cp_Grade: ^Fe 54.25 %, Hi Grade
    Importance Item Commodity Group Amount recovered Grade Recovery percentage
    Major Ore Iron Iron 54wt-pct

Comments on the production information

  • METALLIC IRON 54.22%, MANGANESE 0.141%, PHOSPHORUS 0.012%, SULPHUR 0.014% SELF-FLUXING ORE

Comments on the reserve resource information

  • KNOWN ORE MINED OUT; ORE BED FAULTED; CONTINUATION NOT FOUND; LEAN ORE BEDS REMAIN
  • NO FIGURES AVAILABLE; PROBABLY MUCH LOW GRADE ORE POTENTIAL; PROVEN CONTINUATION OF FAULTED RICH ORE BED WOULD GREATLY INCREASE HIGH AND LOW GRADE POTENTIAL.
  • RICH ORE GRADE MINED OUT, NO FIGURES OF LOW GRADE ORE BUT PROBABLY LARGE; PROVEN EXTENSION OF FAULTED RICH ORE BED WOULD GREATLY INCREASE HIGH AND LOW GRADE RESERVES.

Workings at the site

  • Type of workings Underground
    Length 137.16M
    Overall depth 149.35M

Comments on the workings information

  • SMALL POND ON TOPO MAP LOCATES COLAPSED MINE WORKINGS

Comments on development

  • ECON.COM: EARLY IRON DISTRICT, 1734 - 1900; ORE MINED USED LOCALLY

Reference information

Bibliographic references

  • Deposit

    SMOCK, J.C., 1889, "IRON MINES OF NEW YORK", N.Y.S. MUSEUM BULL. 7, MAP, TEXT, PG 20, 21

  • Deposit

    COLONY, R.J., 1921, "MAGNETITE DEPOSITS SE. NEW YORK", N.Y.S. MUSEUM BULL. 249, MAP, TEXT, PG 124-126

  • Deposit

    NEWLAND, D.H., 1919, "MINERAL RESOURCES OF NEW YORK", N.Y.S. MUSEUM BULL. 223, TEXT, PG 124

  • Deposit

    1889 RECON NEW YORK STATE GEOLOGICAL SURVE

  • Production

    SMOCK, 1889

  • Reserve-Resource

    COLONY, 1921

General comments

Subject category Comment text
Deposit USGS TOPO MAP, 1956, "OSCAWANA LAKE, N.Y.", 1:24,000, MINE NAME AND POND FROM COLAPSED WORKINGS. FE 54.225%, MNO2 0.186%, AL2O3 3.078%, CACO3 1.45%, MGO 10.065%, TIO2 TRACE, CO2 0.251%, P 0.012%, SIO2 8.78%, FL AND ALKALIES 0.427%, S 0.014%, MOISTURE 0.048%, COMBINED WATER 0.758% - SELF FLUXING ORE; SMALL POND OCCUPIES CAVED PORTION. ; INFO.SRC : 1 PUB LIT
Deposit THERE ARE 4 BEDS SOME OF WHICH COALESCE IN SOME PLACES
Deposit Discovery Year: EARLY 1800'S

Reporter information

Type Date Name Affiliation Comment
Reporter 01-JAN-1972 D'Agostino, John P. U.S. Geological Survey

Beyond USGS

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

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