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Big Mike Copper Mine

Past Producer in Pershing county in Nevada, United States with commodities Copper, Silver, Zinc, Cobalt
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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. Mineral occurrence model information
  9. Host and associated rocks
  10. Nearby scientific data
  11. Ore body information
  12. Economic information about the deposit and operations
  13. Mining district
  14. Land status
  15. Ownership information
  16. Reserves and resources
  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 10310578
MRDS ID M060499
Record type Site
Current site name Big Mike Copper Mine
Alternate or previous names NBMG Sample Site 2342

Comments on the site identification

  • This is an updated version of record M060499 for the Big Mike Copper Mine. The current record includes all material from the earlier record plus additional updated material.

Geographic coordinates

Point of reference Pit
Geographic coordinates: -117.5603, 40.5433 (WGS84)
Elevation 1620
Relative position The Big Mike Project is located on the west side of the Sonoma Range about 32 miles south of Winnemucca.

Site location context

Political divisions (FIPS codes)

Pershing(county)

Nevada(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Panther Canyon(quadrangle 1:24,000 scale)

Winnemucca(quadrangle 1:100,000 scale)

Winnemucca(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Lower Humboldt(hydrologic unit)

Humboldt(hydrologic accounting unit)

Black Rock Desert-Humboldt(hydrologic subregion)

Great Basin(hydrologic region)

Federal lands

Bureau of Land Management(Bureau of Land Management NV)

Bureau of Land Management NV BLM(Type of land area)

BLM(Federal land areas administered by BLM)

Geographic areas

Country State County
United States Nevada Pershing

Public Land Survey System information

Meridian Township Range Section Fraction State
Mount Diablo 031N 039E 22 23 Nevada

Comments on the location information

  • The Big Mike Project consists of 17 unpatented lode mining claims and 1 placer mining claim covering a total of 310 acres located south of Panther Canyon and 6 1/2 miles southeast of Leach Hot Springs.

Commodities

Commodity Importance
Copper Primary
Silver Tertiary
Zinc Critical Tertiary
Cobalt Critical Tertiary

Comments on the commodity information

  • Ore Materials: chalcopyrite, bornite, digenite, tenorite, cuprite, sphalerite
  • Gangue Materials: pyrite, iron oxide

Materials information

Materials Type of material
Chalcopyrite Ore
Bornite Ore
Digenite Ore
Tenorite Ore
Cuprite Ore
Sphalerite Ore
Pyrite Gangue

Analytical data

Result Sample 2342 of massive sulfide ore contains +20 % Re, 0.02 % Mg, 0.05 % Ca, 20 % Mn, 100 ppm Ag, 200 ppm B, 100 ppm Ba, +2000 ppm Co, +20000 ppm Cu, 20 ppm Mo, 100 ppm Ni, 70 ppm Pb, 1500 ppm Zn, and 10 ppm Zr

Mineral occurrence model information

Model code 90
USGS model code 24a
Deposit model name Massive sulfide, Cyprus
Mark3 model number 11

Host and associated rocks

  • Host or associated Host
    Rock type Sedimentary Rock > Chemical Sediment > Chert
    Rock unit name Pumpernickel Unit of the Havallah sequence
    Stratigraphic age (youngest) Early Permian
    Stratigraphic age (oldest) Middle Pennsylvanian
  • Host or associated Host
    Rock type Metamorphic Rock > Metavolcanic Rock > Mafic Metamorphic Rock > Greenstone
    Rock unit name Pumpernickel Unit of the Havallah sequence
    Stratigraphic age (youngest) Early Permian
    Stratigraphic age (oldest) Middle Pennsylvanian
  • Host or associated Host
    Rock type Sedimentary Rock > Clastic Sedimentary Rock > Argillite
    Rock type qualifier cherty, carbonaceous
    Rock unit name Pumpernickel Unit of the Havallah sequence
    Stratigraphic age (youngest) Early Permian
    Stratigraphic age (oldest) Middle Pennsylvanian
  • Host or associated Host
    Rock type Sedimentary Rock
    Rock type qualifier turbidite
    Rock unit name Pumpernickel Unit of the Havallah sequence
    Stratigraphic age (youngest) Early Permian
    Stratigraphic age (oldest) Middle Pennsylvanian

Nearby scientific data

Pit (1) -117.5603, 40.5433
ListMap

Economic information

Ore body information

  • General form stratiform
  • Thickness 90M
    Length 180M
    Width 90M
    Area 3.4HA
    Depth to top 12M
    Field Value
    Type of Orebody #1 BRECCIA FILL
    Shape of Orebody #1 LENTICULAR
    Type of Orebody #2 REPLACEMENT
    Primary mode of Origin HYDROTHERMAL
    Secondary mode of Origin OXIDATION
    Primary Ore Control FAULTING
    Degree of Wallrock Alter. INTENSE
    Type of Wallrock Alter. #1 INTERM ARGILLIC
    Strike And Dip N90E:
    Minimum Depth to Top 6
    Avg. Thick. Unconsol. Mat. 12
    Min. Thick. Unconsol. Mat. 6
    Total Surface Area (HA) 3.4
    Date of Last Modification 830708

Economic information about the deposit and operations

Operation type Surface
Development status Past Producer
Commodity type Metallic
Deposit size Small
Significant Yes
Discovery year 1930
Year of first production 1966
Year of last production 1979
Production years 1966; 1970; 1971-1974; 1978-1979

Mining district

District name Tobin and Sonoma Range area

Land status

Ownership category BLM Administrative Area
Area name Winnemucca BLM District

Ownership information

  • Type Owner
    Owner Ranchers Exploration, Hecla Mining Co.
    Last year 1984
  • Type Owner-Operator
    Owner GoldSpring, Inc.
    Year 2006
  • Type Unknown
    Owner Ranchers Exploration and Development Corp.
    ID 2600088
    Interest 100
    Home office New Mexico

Reserves and resources

  • Type In-situ
    Estimate year 1979
    Commodity Subtype Grade units Group Importance Year
    Copper Cu 0 wt-pct Copper Trace 1979
  • Type In-situ
    Estimate year 1969
    Measured 577000mt ore
    Indicated 577000mt ore
    Demonstrated 1154000mt ore
    Inferred 577000mt ore
    Total resources 1731000mt ore
    Commodity Subtype Grade units Group Importance Year
    Copper Cu 3.9 wt-pct Copper Trace 1969

Workings at the site

  • Type of workings Underground
    Field Value
    MAS Development Schedule # 1
    Mining Record # 1
    Status of Mining Method ESTIMATE
    Mining Method LEACHING IN PLACE (IN SITU) 10-89
    Capacity Units MT ORE/DAY
    Units of Production $/MT ORE
    Year of Information 1976
  • Type of workings Underground
    Field Value
    MAS Development Schedule # 1
    Mining Record # 2
    Status of Mining Method ESTIMATE
    Mining Method LEACHING IN PLACE (IN SITU) 10-89
    Capacity Units MT ORE/DAY
    Units of Production $/MT ORE
    Year of Information 1976

Comments on the workings information

  • open pit mine of moderate size, dumps, core storage building (walls missing with thousands of meters of core inside-1980s).

Comments on other economic factors

  • Ranchers Exploration and Development Co. produced 25 million pounds of copper from direct-shipping, high-grade copper sulfide ore from this property in 1970.
    The original estimates of reserves and resources were done by Ranchers. During the period from 1970 to 1979 Ranchers removed approximately 26 million pounds of copper in all forms. This was from an original estimate of 51 million pounds of copper. BMLP recalculated the reserves and resources from a re-examination of the Ranchers work and a sampling program on the broken ore remaining.
    A technical report available on the Goldspring website, 2006 reports the following mineable reserves on the Big Mike mine site.
    On Heap 319,000 tons of ore at 1.32%, 8,400,000 pounds of copper
    In Pit 640,000 tons of ore at 1.01%, 12,900,000 pounds of copper
    Dumps 134,000 tons of ore at 0.60%, 1,600,000 pounds of copper
    Pit Walls 103, 000tons of ore at 1.06%, 2,200,000 pounds of copper
    TOTAL 1,196,000 tons of ore at 1.05 % average grade, 25,100,000 mineable pounds of copper

Comments on development

  • Copper occurrences were known in the area at about the turn of the last century. The project area was claimed in the early 1900s by the Foster family, but very little exploration was done and no development work was done. In 1966, Mr Clair Chamberlain optioned the property and undertook a sampling program. As a result of the sampling, some copper oxide ore was shipped to ASARCO in Tacoma, Washington. From this work the Big Mike Corporation was formed to develop and exploit the copper oxide ore by heap leaching. A small pad was developed and copper precipitate was produced.
    In 1967, the Big Mike Corporation entered into a joint venture with Cerro Corporation to explore the property further and this led to the discovery of a high grade copper sulfide orebody. By 1970, Ranchers? Exploration and Development Corporation acquired the property from Cerro Corporation and confirmed the sulfide orebody, which was rapidly developed via an open pit. In fact all the high grade ore was mined and directly shipped to smelters in 1970. The remaining oxide ore and the mixed and low grade sulfide ore was crushed for heap leaching. In the pit, similar low grade ore was blasted from the walls of the pit for leaching in the bottom of the pit.
    Heap leaching was carried out during two periods, from 1971 to 1974 and then 1978 to 1979. Both periods were curtailed by low copper prices. In 1979 Ranchers abandoned the claims. The claims were subsequently staked and reclaimed by WR & A. Big Mike Limited Partnership (BMLP) purchased the claims from WR & A., in 1988.
    During the period from 1988 to 1992 BMLP undertook project studies to establish reserves, identify a treatment method, and gain environmental permits to develop the project. A considerable amount of work was done, but the project did not get underway.
    John Cook and Dan Mackie examined data from the project in the spring of 1997 and concluded that it would be suitable for continuous vat leaching with the EcoVat. After this work an option agreement was entered into. GoldSpring, Inc. acquired 100% of this project.
    Th current Big Mike project is an oxide copper recovery project with the copper oxides remaining from a previous rich sulfide operation. The property also has exploration potential for further copper oxides and copper sulfides
    In 2005, GoldSpring, Inc. signed a memorandum of understanding with MBMI Resources Inc. to acquire a 50% interest in the 310-acre Big Mike copper property located 32 miles south of Winnemucca. Big Mike is a volcanogenic massive sulfide deposit that consisted of a secondarily-enriched pod of massive copper and iron sulfides enveloped by altered rock containing zones and disseminations of secondary copper mineralization. Ranchers Exploration and Development Co. produced 25 million pounds of copper from direct-shipping, high-grade copper sulfide ore from this property in 1970. Five target areas have been identified for additional exploration on and adjacent to the Big Mike property.

Reference information

Bibliographic references

  • Deposit

    Johnson, Maureen G., 1977, Geology and Mineral Deposits of Pershing County, Nevada' Reno: Nevada Bureau of Mines and Geology Bulletin 89, 115p.

  • Deposit

    Engineering Mining Journal, 1971, 1973.

  • Deposit

    Rye, R.O., et al., 1984, Economic Geology, volume 79, p. 124-140.

  • Deposit

    Garside, L.J., 11 Sep 84, NBMG Field Examination and sample analysis.

  • Deposit

    NBMG Staff, 1985, NBMG 85-3.

  • Deposit

    Snyder, W.S., 1977, Ms Thesis, University Of Nevada-Reno.

  • Deposit

    Hart, D.D., 1977, Unpublished report on ores of Big Mike Mine, NBMG Mining District File 270, Item # 11.

  • Deposit

    Carithers, W. and Forbes, J.M., 1969, Unpublished report on Big Mike Property; NBMG File 270, Items #12 and #13.

  • Deposit

    Intermountain Pay Dirt, Oct 1984,

  • Deposit

    GoldSpring, Inc. press release, 11/1/05.

  • Deposit

    Techncial report at http://www.goldspring.us/mike.htm

General comments

Subject category Comment text
Deposit Big Mike is a high-grade, low tonnage, cupriferous pyrite volcanogenic stratiform massive sulfide deposit. It consists of a massive lens that occurs entirely within a thin cherty carbonaceous argillite. A stringer zone occurs in the footwall pillow basalt and a minor stringer zone occurs north of the massive lens in the hanging wall pillow basalt. Much of the dump material and pit wall consists of pillow lava, chert and argillite with varying amounts of limonite gossan and oxide copper minerals. The main deposit is volcanogenic massive sulfide of the hot springs type which occurs in the Havallah sequence. This is a thick greenstone complex in the Pumpernickel formation. When discovered the deposit consisted of a secondarily enriched pod of nearly massive copper and iron sulfides enveloped by altered rock containing zones and disseminations of secondary copper mineralization. The mineralogy is complex as various secondary effects are apparent. The structure of the area is also complex though the deformation of the Big Mike area is not so severe as other parts of the Havallah sequence.
A shear zone runs through the Big Mike pit and extends approximately 1,000 feet in the south east and northwest directions away from the pit. This is also the general strike of the area with dips 40 to 60 degrees to the north east. This shear zone may be an indicator of further deposits. Five target areas have been identified for additional exploration on and adjacent to the Big Mike property. These targets show potential to extend the existing ore zone and for additional ore bodies.

Reporter information

Type Date Name Affiliation Comment
Reporter 01-JAN-1980 Harner, Joy L. (Roberts, Ralph J.) Nevada Bureau of Mines and Geology
Updater 01-MAR-1987 La Pointe, D.D. U.S. Geological Survey
Reporter 23-NOV-1994 Linne, James M. U.S. Bureau of Mines
Reporter 01-DEC-2006 LaPointe, D.D. Nevada Bureau of Mines and Geology
Editor 01-SEP-2007 Schruben, Paul G. U.S. Geological Survey Converted from S&A FileMaker format to Oracle. Edit checks on rocks, units, and ages with Geolex search, and other fields.

Beyond USGS

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

External references

Maps centered on this site

Authoritative Nevada resources

These are landing pages for further research — the state agencies don't currently expose per-mine deep links.