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MacArthur Copper Deposit

Past Producer in Lyon county in Nevada, United States with commodity Copper
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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. Controls for ore emplacement
  13. Economic information about the deposit and operations
  14. Mining district
  15. Land status
  16. Ownership information
  17. Reserves and resources
  18. Links to other databases
  19. Bibliographic references
  20. General comments
  21. Reporter information

Geologic information

Identification information

Deposit ID 10310387
MRDS ID N000424
Record type Deposit
Current site name MacArthur Copper Deposit
Related records 10310388

Comments on the site identification

  • All material in earlier MRDS record N000424 has been incorporated into the current record, as well as additional new information.

Geographic coordinates

Geographic coordinates: -119.2407, 39.04741 (WGS84)
Relative position The MacArthur property is located about six miles northwest of the town of Yerington.

Site location context

Political divisions (FIPS codes)

Lyon(county)

Nevada(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Mason Butte(quadrangle 1:24,000 scale)

Carson City(quadrangle 1:100,000 scale)

Reno(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Walker(hydrologic unit)

Walker(hydrologic accounting unit)

Central Lahontan(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 Lyon

Public Land Survey System information

Meridian Township Range Section Fraction State
Mount Diablo 013 N, 14N 024E 025 E 08 09 16 17 20 21 25 Nevada

Comments on the location information

  • The MacArthur property is located about five miles NNW of the Yerington open pit copper mine in the Singatse Range about a mile south of Carson Hill.

Commodities

Commodity Importance
Copper Primary

Comments on the commodity information

  • Ore Materials: chalcocite, chalcopyrite
  • Gangue Materials: pyrite
  • Associated Minerals: actinolite, azurite/malachite, biotite, chalcocite, chalcopyrite, chrysocolla, goethite/limonite, pyrite, tenorite
  • Associated Rock: granite porphyry, quartz monzonite porphyry;argillite, gypsum, ignimbrite, rhyolite, sandstone, volcaniclastic rocks;andesite, granite, hornfels, quartz monzonite, skarn

Materials information

Materials Type of material
Chalcocite Ore
Chalcopyrite Ore
Pyrite Gangue

Alteration

  • (Local) Green-stained outcrops of copper-rich rock occur in the mine area.

Analytical data

Result As of 1976, 6.5 Mt of Oxide ore

Mineral occurrence model information

Model code 53
USGS model code 17
Deposit model name Porphyry Cu
Mark3 model number 4

Host and associated rocks

  • Host or associated Host
    Rock type Plutonic Rock > Granitoid > Quartz Monzonite
    Stratigraphic age (youngest) Jurassic
    Stratigraphic age (oldest) Triassic
  • Host or associated Associated
    Rock type Plutonic Rock > Granitoid > Granodiorite
    Stratigraphic age (youngest) Jurassic
    Stratigraphic age (oldest) Triassic

Nearby scientific data

(1) -119.2407, 39.04741
ListMap

Economic information

Controls for ore emplacement

  • The primary mineralization consisted of pyrite and chalcopyrite sparsely disseminated.

Economic information about the deposit and operations

Operation type Surface-Underground
Development status Past Producer
Deposit size Large
Significant Yes
Year of first production 1995
Year of last production 1997

Mining district

District name Yerington District

Land status

Ownership category Private
Ownership category BLM Administrative Area
Area name Carson City BLM Administrative District

Ownership information

  • Type Owner-Operator
    Owner Quaterra Resources Inc.
    Year 2006
  • Type Owner
    Owner Arimetco International, Inc.
    Interest 50
    Home office Tuscon, AZ
    Year 1992
  • Type Owner
    Owner Holcorp Mines Ltd.
    Interest 50
    Year 1992
  • Type Owner
    Owner Anaconda Co.
    Interest 100
    Year 1975

Reserves and resources

  • Type In-situ
    Estimate year 1994
    Total resources 87300000mt
    Commodity Subtype Grade units Group Importance Year
    Copper Cu 0.21 wt-pct Copper Primary 1994

Comments on the workings information

  • The mine area is developed by extensive trenching and diamond drilling, open pit mine and heap leach operation
  • EXTENSIVE TRENCHING AND DIAMOND DRILLING. HEAP LEACH.

Comments on other economic factors

  • In 1994, MacArthur was reported to contain an estimated proven and probable oxide copper reserve of 97 million tons containing 0.21% Cu.
    In 1995, MacArthur was reported to contain an estimated 51 million tons of oxide copper ore with an average grade of 0.26% copper.
    In 2006, the MacArthur oxide deposit was reported to contain a remainng resource of 29 million tons grading 0.28% copper, including 13 million tons of +0.40% copper.

Comments on development

  • Small-scale high-grade copper production began in 1943. The major period of porphyry copper exploration in the Yerington area began in the 1950s. The area was again extensively explored in the 1960s and in the 1970s Anaconda mined the main Yerington deposit. Copper mining in the historically active Yerington district in Lyon county ceased in the late 1970s.
    In 1992 Arimetco International Inc. of Tucson, AZ. acquired a 50% interest (Holcorp Mines Ltd. owned 50%) in the Yerington property and began mining. Arimetco mined, stacked and leached ore at a rate of almost 2 million tons annually.
    In 1994 Arimetco International produced 10 million pounds of copper from the Yerington mine, equal to 1993 production. This figure was expected to increase when production from the nearby MacArthur property began. Permits for development of the MacArthur copper deposit were finally received by Arimetco International and development of the deposit started. MacArthur crops out at the surface and contains estimated proven and probable oxide copper reserves of 97 million tons containing 0.21% Cu. Yerington mine had an open-pit oxide reserve of about 15 million tons averaging 0.32% copper at that time. In 1994, Arimetco entered into an agreement with Billiton Metals Inc. for Billiton to finance an expansion of the Yerington-MacArthur solvent extraction-electrowinning plant for cathode copper from 50,000 pounds per day to 80,000 pounds per day. Arimetco planned to complete the expansion by the end of 1994. Copper production increased by 30% from 1994 to 1995 as Arimetco, Inc. opened its new MacArthur Mine near its Yerington facility. 1995 copper production by Arimetco International Inc. from the Yerington and MacArthur Mines in Lyon County totaled almost 13 million pounds, up from 10 million pounds in 1994.

    In 1995, Arimetco International Inc. began operations at its MacArthur deposit from a 12-million-ton starter pit with an average grade of 0.33% copper. Ore was being trucked to leach facilities at Arimetco's nearby Yerington Mine. At the Yerington Mine, Arimetco planned to begin a 2-year project for dewatering the pit, preparatory to mining sulfide ore left by Anaconda, and permitting was underway for a 20,000 ton-per-day mining, crushing, and concentrating operation. Arimetco reported that the Yerington pit contained provable and developed sulfide ore of 50 million tons grading 0.49% copper with a 0.70:1 tripping ratio. Meanwhile, Arimetco was processing 18.5 million tons of low-grade oxide dump material by heap-leaching, yielding about 5,000 pounds of copper per day. In 1996, Copper production by Arimetco International Inc. from the Yerington and MacArthur Mines in Lyon County totaled 15 million pounds.

    In 1997 low copper prices caused Arimetco, Inc. to curtail mining at its MacArthur project after producing slightly over 10.5 million pounds from the combined Yerington operations in 1997.
    Quaterra Resources Inc acquired the MacArthur property and in 2006 planned to drill it and develop it. Quaterra began a first phase program consisting of data review and compilation in late 2006. During the first half of 2007 Quaterra plansa limited confirmation drilling program to validate the historic resource, calculate an oxide resource and complete a technical report. Drilling will also be initiated to determine the size and grade of the porphyry system beyond the pit boundaries.
  • A MAJOR EXPLORATION IN 1950. AREA WAS AGAIN EXTENSIVELY EXPLORED IN THE 1960'S AND 1975. ; ECON.COM: PRODUCTION : 14 CARLOADS OF ORE, AVERAGING 1.22 PERCENT COPPER, WAS SHIPPED IN 1943. ARIMETCO SAYS THAT ORES WILL BE MINED, STACKED AND LEACHED AT A RATE OF ALMOST 2 MILLION TONS ANNUALLY TO PRODUCE 4,400 TONS OF COPPER. WHEN PROJECT DEVELOPMENT IS COMPLETED IT WILL ADD 6.4 TONS PER DAY TO YERINGTON'S CURRENT RATE OF 12 TONS PER DAY. ( ROBERTO,1992)

Reference information

Bibliographic references

  • Reserve-Resource

    Arimetco 1993 Annual Report

  • Deposit

    Telluride Claims, Yerington Mining District, Lyon County, Quade Visit Site 7-11-89,NBMG Unpublished Mining District Files (Tingley Files).

  • Deposit

    Roberto, Marguerite, 1992, USBM Minerals Today, Oct. 1992, p. 28.

  • Deposit

    northern Miner Sept. 18, 1989 And Oct.7, 1991

  • Deposit

    Skillings 9/19/92

  • Deposit

    Long, K.R., DeYoung, J.H., Jr., and Ludington, S.D., 1998, Database of significant deposits of gold, silver, copper, lead, and zinc in the United States; Part A, Database description and analysis; part B, Digital database: U.S. Geological Survey Open-File Report 98-206, 33 p., one 3.5 inch diskette.

  • Deposit

    NBMG MI-1994

  • Deposit

    NBMG MI-1995.

  • Deposit

    Anonymous, 1994, MacArthur permits in hand; The Northern Miner, January 3 issue, p. 3.

  • Deposit

    Denver Mining Record, 8/31/94

  • Deposit

    Engineering & Mining Journal, 5/1/95

  • Deposit

    Rocky Mountain Pay Dirt, 5/1/95

  • Deposit

    Northern Miner, 5/15/95.

  • Deposit

    Jurassic Magmatism and Metal Deposits in Western Nevada, 2002, Spring Field Trip Guidebook, Geological Society of Nevada Special Publication No. 35.

  • Deposit

    Anonymous, 1993e, Arimetco boosts MacArthur interest: The Northern Miner, May 31, p. 6.

  • Deposit

    Albino, G.V., 1995, Porphyry copper deposits of the Great Basin?Nevada, Utah, and adjacent California, in Pierce, F.W., and Bolm, J.G., eds, Porphyry copper deposits of the American Cordillera: Tucson, Arizona Geological Society Digest 20, p. 267?296.

  • Deposit

    Dilles, J.H., and Proffett, J.M., 1995, Metallogenesis of the Yerington batholith, Nevada, in Pierce, F.W., and Bolm, J.G., eds., Porphyry copper deposits of the American Cordillera: Tucson, Arizona Geological Society Digest 20, p. 306?315.

  • Deposit

    Einaudi, M.T., 1982, Description of skarns associated with porphyry copper plutons, in Titley, S.R., ed., Advances in geology of the porphyry copper deposits, southwestern North America: Tucson, University of Arizona Press, p. 139-183.

  • Deposit

    Heatwole, D.A., 1978, Controls of oxide copper mineralization, MacArthur property, Lyon County, Nevada: Arizona Geological Society Digest, v. 11, Tucson, p. 59?66.

  • Deposit

    Steininger, R.C., 1995, Great Basin, exploration review: SEG (Society of Economic Geologists) Newsletter, no. 22, July, p. 26.

General comments

Subject category Comment text
Deposit The MacArthur mine occurs in a quartz monzonite intrusive of Jurassic age that has been intruded by a series of northwesterly-trending steeply dipping quartz monzonite porphyry, rhyolite and andesite dikes. The copper mineralization is zoned, with a chalcopyrite-rich (low iron to copper ratio) eastern area grading into a pyrite halo (high iron to copper ratio) to the north and west. Oxide mineralization overlies the chalcopyrite-rich area and consists of copper oxides and silicates (malachite, chrysocolla), copper wad and iron oxides
Deposit SAMPLE 4414 WAS A RANDOM SAMPLE FROM THE NORTH-SOUTH TRENCHES. SAMPLE 4415 WAS FROM ONE OF THE INCLINES SUNK ON A QUARTZ VEIN IN THE NORTHERN PART OF THE DEPOSIT.
Deposit AT THE SURFACE, THE DEPOSIT HAS A WIDESPREAD IRON-OXIDE CAPPING WITH MANY GREEN STAINED OUTCROPS OF COPPER COVERING AN AREA ABOUT ONE-HALF MILE WIDE.

Reporter information

Type Date Name Affiliation Comment
Reporter 10-JUN-92 Beougher, Dee U.S. Geological Survey
Editor 01-SEP-07 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.
Updater 10-JUN-92 Doebrich, Jeff L. U.S. Geological Survey
Updater 07-APR-10 Anderson, Claire U.S. Geological Survey

Beyond USGS

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

Operator history (post-MRDS)

MRDS records operators as of each record's last update (≤ 2019). Some of the operators listed here have since changed hands or dissolved:

  • Anaconda Co. — dissolved ~1977
    Acquired by Atlantic Richfield (ARCO) in 1977 and shut down most operations in the 1980s. Mineral assets were sold off piecemeal; some are now in Glencore via intermediate owners.

Curated by qvyshift.com from publicly-reported M&A activity (SEC filings, press releases, USGS Mineral Yearbooks). Not authoritative — verify against primary sources before relying on it. The MSHA panel above is the current authoritative source for actively-permitted mines.

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.