Montana Resources (Butte/Berkely/Continental)

Site Name

Primary: Montana Resources (Butte/Berkely/Continental)
Secondary: Berkeley Pit
Secondary: Berkeley Underground
Secondary: Copper Moly Dome
Secondary: Continental East
Secondary: Continental West
Secondary: Kelly
Secondary: Badger
Secondary: Elm
Secondary: Berkeley Neck
Secondary: Butte
Secondary: Continental Area
Secondary: Badger-Elm
Secondary: Orlu

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Commodity

Primary: Copper
Primary: Silver
Primary: Molybdenum
Secondary: Gold
Tertiary: Zinc
Tertiary: Manganese
Tertiary: Lead

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Location

State: Montana
County: Silver Bow
District: Butte District

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Land Status

Land ownership: Private
Note: the land ownership field only identifies whether the area the mine is in is generally on public lands like Forest Service or BLM land, or if it is in an area that is generally private property. It does not definitively identify property status, nor does it indicate claim status or whether an area is open to prospecting. Always respect private property.

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Holdings

Type: Fee Ownership
Type: Patented
Type: Private Lease

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Workings

Type: Surface

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Ownership

Owner Name: Asarco (American Smelting And Refining Co.)
Percent: 49.90
Home Office: New York
Info Year: 1994

Owner Name: Montana Resources Inc.
Company ID: 2400338
Percent: 51.10
Home Office: Montana
Info Year: 1994

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Production

Year: 1999
Mined: 17014000.000 mt
Material type: ore
Year: 1998
Mined: 17514000.000 mt
Material type: Ore milled. Asarco 1998 10K.
Year: 1997
Mined: 13806000.000 mt
Material type: Ore milled. Asarco 1998 10K.
Year: 1996
Mined: 14506000.000 mt
Material type: Ore milled. Asarco 1998 10K.
Year: 1995
Mined: 13474000.000 mt
Material type: Ore milled. Asarco 1997 10K.
Year: 1993
Mined: 15267000.000 mt
Material type: Ore milled. Asarco 1995 10K
Year: 1994
Mined: 13791000.000 mt
Material type: Ore milled. Asarco 1996 10K
Year: 1992
Mined: 16103000.000 mt
Material type: Ore milled. Asarco 1994 10K.
Year: 1983
Time Period: 1882-1983
Description: 1882-1983: Copper Production 8915000 Metric Tons, Silver Production 21694000 Kilograms, Gold Production 89940 Kilograms, Zinc Production 2226999 Metric Tons, Manganese Production 1679999 Metric Tons, Lead Production 387740 Metric Tons
Year: 1983
Time Period: 1981-1983
Description: Molybdenum Production 6960 Metric Tons
Year: 1991
Mined: 15932000.000 mt
Material type: Ore milled. Asarco 1993 10K.
Year: 1982
Time Period: 1952-1982
Mined: 662661973.82 mt
Material type: ore

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Deposit

Record Type: Deposit
Operation Category: Producer
Deposit Type: Porphyry Cu-Mo
Plant Type: Beneficiation (Mill)
Plant Subtype: Flotation
Operation Type: Surface
Mining Method: Open Pit
Milling Method: Flotation
Year First Production: 1882
Discovery Year: 1864
Years of Production:
Organization:
Significant: Y
Deposit Size: M

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Physiography

General Physiographic Area: Rocky Mountain System
Physiographic Province: Northern Rocky Mountains

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Mineral Deposit Model

Model Name: Porphyry Cu-Mo

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Orebody

Form: Tabular

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Structure

Type: R
Structure: Boulder Batholith

Type: L
Structure: NORTHEAST-STRIKING NORMAL FAULTS

Type: R
Structure: LEWIS AND CLARK LINEAMENT

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Alterations

Alteration Type: L
Alteration: OXIDATION, PYRITIZATION, SERICITIZATION

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Rocks

Name: Porphyry
Role: Associated
Description: QUARTZ PORPHYRY DIKES AND PLUGS
Age Type: Associated Rock
Age Young: Cretaceous

Name: Quartz Monzonite
Role: Host
Description: quartz monzonite-monzogabbro suite
Age Type: Host Rock
Age Young: Cretaceous

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Analytical Data

Not available

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Materials

Ore: Chalcopyrite
Ore: Sphalerite
Ore: Molybdenite
Ore: Gold
Ore: Galena
Ore: Enargite
Ore: Cuprite
Ore: Covellite
Ore: Chrysocolla
Ore: Chalcocite
Ore: Bornite
Ore: Azurite
Ore: Silver
Gangue: Pyrite
Unknown: Rhodonite
Unknown: Huebnerite
Unknown: Tennantite
Unknown: Tenorite
Unknown: Tetrahedrite
Unknown: Rutile
Unknown: Rhodochrosite
Unknown: Quartz
Unknown: Pyrolusite
Unknown: Marcasite
Unknown: Malachite
Unknown: Magnetite
Unknown: Kaolin
Unknown: Gypsum
Unknown: Fluorite
Unknown: Digenite
Unknown: Chalcanthite
Unknown: Calcite
Unknown: Barite
Unknown: Wurtzite
Unknown: Sericite

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Comments

Comment (General): SEE Deposit ID 10400191 Butte, Veins (Anaconda)

Comment (Deposit): Associated Deposits: Main stage veins (?Cordilleran-style? polymetallic (Cu, Pb, Zn, Ag, Au, Mn) veins)

Comment (Production): In 2005, Montana Resources, Inc. produced copper, molybdenum, and silver from the Continental Pit Mine. Ore grades remained steady at 0.20% copper and 0.025% molybdenum. Assembly of a 31-cubic-meter electric shovel was completed and placed into production in late summer. Significant improvements were made at the mill in upgrading the electric circuitry and computer controls. A plan was also in place to upgrade the ancillary equipment at the mine and mill during 2006. Montana Resources also began investigating the feasibility of starting production in the supergene zone between the Berkeley Pit and the Continental Pit. Pumping tests were started late in 2005 and a drilling program was planned for 2006. Pending favorable results, production of copper was expected to be substantially increased at the mine. (USGS 2005)

Comment (Geology): Primary Minerals Pyrite Is Most Abundant Metallic Mineral Marcasite May Aid In Promoting Secondary Enrichment Bornite Some Primary Most Is Secondary. Chalcopyrite Primary In Granite Secondary Elesewhere. Chalcocite Most Abundant Copper Mineral Secondary. Covellite Secondary, Rare Enargite 2nd Most Abundant Cu Mineral Primary. Tetrahedrite Primary. Tennantite Rare. Sphalerite Common Primary Zinc Mineral Secondary. Galena Primary Common. Molybdenite Common Primary Mineral In Cu-Mo Dome. Manganese Minerals Rhodochrosite,Rhodinite,Pyrolusite. Gold Often Occurs With Tellurium And Selenium In Minor Amounts. Silver Native Silver Occurs As Coatings Wire And Fibers Exotic Minerals Include; Pyrargyrite;Digenite;Hubnerite Wurtzite;Wulfenite. Oxidized Minerals Occur In Minor Amounts Chrysocolla In Veins Malachite Surface Outcrops. Azurite Surface Outcrops. Copper Pitch Rare. Chalcanthite Most Abundant Mineral In The Oxide Zone. Pisanite Resulting From Seepage. Goslarite Forming On Walls Of Old Workings. Melaconite Rare. Tenorite Rare. Minerals Of The Gangue:In Decreasing Order Of Abundance. Sericite Magnetite Rutile Kaolin Gypsum Calcite Fluorite Barite Rhodonite Rhodochrosite

Comment (Reserve-Resource): Additional Inferred Resources: Berkeley Neck (Kelly)- 196 Million Mt @ 1.07 % Cu Berkeley Pit - 81 Million Mt @ 0.71 % Cu Copper-Moly Dome- 680 Million Mt @ 0.85 % Cu Source- Montana (Butte) Standard, 6/2/85.

Comment (Deposit): From Meyer And Others (1968): Anaconda Veins (Major Producers In The West Third And In The East Third Of The District) Follow East-West Striking Quartz-Porphyry Intrusives. Blue Veins (Northwest-Striking), In The Central Portion Of The Deposit Fault The Anaconda Veins. Rusk and others (2000) define several stages of mineralization.

Comment (Ownership): Company Address: Montana Resources Inc. 600 Shields Butte, Mt 59701 Asarco Incorporated 180 Maiden Lane New York, Ny 10038

Comment (Geology): Other Porphyry Copper Deposit With Classic Horsetail Vein Structure Well Developed Example Of Concentric Mineral Zoning Of Hydrothermal Deposits. Classic Example Of Zoned Altered Porphyry Copper

Comment (Exploration): Placer Production Was First Until 1867. Silver Mining Started On A Limited Scale In 1866. The Anaconda Claim Started The High Grade Copper Production In 1882. Mn Was First Produced In 1917. Zn Started Around 1916. In 1944 The First Major Change In Mining Methods, It Was Block Caving. Nature Of Discovery Also: B Ore Mineral In Place. Updated By Mbmg (2000) From Winer, 2000. 1864-Placer Gold Discovered By Budd Parker, P. Allison, And James And Joseph Esler. 1866-Mining District Formed 1867-Gold Placer Mining ?Era? Over Mainly Due To Lack Of Water. 1874-William Farlin Assays Samples For Silver And Copper, Stakes ?Asteroid? Later Known As The ?Travona? Claim. 1876-First Profitable Treatment Of Silver Ore At The Dexter Mill (Backed By William A. Clark). 1879-First Successful Copper Smelter In Butte (Colorado Smelting Company). 1880?S To 1999-Copper Also Recovered In Varying Amounts By Precipitation Of ?Copper Cement? In Leach/Precipitation Plants. 1882-Marcus Daly Makes Major Copper Discovery At The Anaconda Mine. 1884-First Smelter In Ananconda Finished. 1887-Silver Era Peaks; Mills Treating 400 Tons Of Ore Per Day; Mainly By Open Roasting And Mercury Amalgamation. 1891-Anaconda Mining Company (Daly Syndicate) Formed, Later Called The Anaconda Copper Mining Company (1895) Which, In Turn, Was Controlled By The Amalgamated Copper Company (1899). 1893-End Of Silver Era With The Panic Of 1893. 1906-Consolidation Of Individual Mines Into The ?Amalgamated Copper Company?, Called The Anaconda Copper Mining Company After 1910 When Amalgamated Holdings Were Acquired By Anaconda. Amalgamated Dissolved In 1915. 1944 To 1962-Block Caving Mining Tested And Then Supercedes Basic Drilling And Blasting Underground Methods To Mine Ore (300,700 Tons Of Copper Ore Mined This Way During This Time). 1952-Block Caving At The Kelley Mine Fully Operational. 1955-Berkeley Pit Started (Stripping Overburden In March And Ore Production In July, 1955). 1974/75-End Of Anaconda Com

Comment (Deposit): Secondary Enrichment In The Southeastern Part Of The District, Mined In The Berkeley Pit (Meyer And Others, 1968). Upper 300 To 400 Feet Affected By Supergene Alteration (Perry,1932)

Comment (Geology): Boulder Batholith, Lewis And Clark Lineament (To North), East-West Lineament That Is The Northern Edge Of The Archean Block (To South). Butte Is In The Wedge-Shaped Central Block Between These Other Two Blocks, (Meyer And Others, 1968).

Comment (Deposit): Pervasive Sericitic Alteration (Rusk And Others, 2000). Sericite-Biotite-K-Feldspar Alteration Envelopes Enclose Molybdenite And Chalcopyrite Veinlets In Deep Levels In The Center Of The District. Pre-Main Stage Potassium Silicate Alteration Adjoins Some Quartz-Moly Veinlets. The Potassium Silicate Assemblage Includes K-Spar, Biotite, Sericite, Pyrite And Chalcopyrite. The Main Stage Alteration Includes Advanced Argillic And Sericitic Alteration In The (Central) Copper Zone, With Pervasive Sericitization Of The Quartz Monzonite And Silicification And Advanced Argillic Alteration Locally. The (Intermediate) Copper-Zinc Zone Includes Gradations From Fresh Quartz Monzonite, To Argillic (Green Montmorillonite To White Kaolinite Zones) To Sericitic Alteration Adjacent To The Vein. The Peripheral Zinc-Manganese Zone Includes Alteration From Fresh Quartz Monzonite To A Smaller Montmorillonite Then Kaolinitic (Argillic) Alteration And Sericitic Zones. Post-Main Stage Alteration Includes A Small Monmorillonite/ Kaolinite Subzone; 0?-6? Of Argillic Alteration On Late Faults And Joints With Sone Pyritization Of Biotite (Meyer And Others, 1968). See Also Sales And Meyer, 1948 For Description Of Wall Rock Alteration At Butte. They Postulate That The Sericitization And Argillitization Were Contemporaneous

Comment (Economic Factors): Production As Of Jan. 1, 1965: (From Meyer And Others, 1968) Total Tons Ore Mined - 326,857,074; With 272,492,476 From The Berkeley Pit Of Which 68,573,478 Were Ore. Metal Production From The Butte Hill As Of 1965: Copper-16,188,113,874 Pounds Zinc-4,792,562,266 Pounds Lead-836,691,887 Pounds Manganese-3,702,787,341 Pounds Silver-644,801,110 Ounces Gold-2,506,253 Ounces Total Butte Metal Production 1880-1991 (All Mining Methods And Ore Types). From Winer, 2000. Copper-20,428,831,775 Pounds Zinc-4,909,202,540 Pounds Manganese-3,702,787,341 Pounds Lead-854,797,405 Pounds Silver-706,019,918 Ounces Gold-2,922,446 Ounces (Estimated Due To Incomplete Records) Cadmium-4,306,156 Pounds Bismuth-4,042,663 Pounds Sulfuric Acid-9,456,105 Dry Short Tons Selenium-316,855 Pounds Tellurium-237,256 Pounds Molybdenum-52,344,889 Pounds This Information Was Cited From Malone And Miller (1973) And A Telephone Interview With George Burns, Chief Geologist, Montana Resources (1992).

Comment (Workings): Open Pit, Shafts, Tunnels, Adits, Etc.; Underground Workings In The Butte Mines Include 42 Miles Of Vertical Shafts, Together With 2,681 Miles Of Other Passageways. Adding The Excavation From Stopes Brings The Total Length Of The Various Workings Which Have Been Opened Underground To About 10,000 Miles. Berkeley Pit- Mined 400 Million Tons Of Copper Ore; Approximately 1 Mile Long And 1 Mile Wide ; 50,000 Tons Of Ore Per Day Mined At The Maximum (Gcm Services, 2000).

Comment (General): Mining In The Continental Pit Suspended July 2000 Due To Uneconomic Conditions Created By Electric Rate Increases. Still Suspended As Of September 2000 (Current). Underground Mines Include The Mountain Consolidated (Mount Con), Steward, Original, Granite Mountain, Speculator, Kelley, Leonard, Badger State, Elm Orlu, Emma, Travona, Orphan Girl, Orphan Boy, Nettie, Norwich, Bluebird, Anselmo, Lexington, Alice, Black Rock, Pittsmont, Belmont, Anaconda, High Ore, Marget Ann, Etc. Open Pits Include The Berkeley, (East) Continental, Syndicate, Alice, Bullwhacker, Butte-Duluth, Etc

Comment (Deposit): The Following Is From Meyer And Others, 1968: Steward Veins And Faults; Rarus Fault; Middle Fault Systems; Continental Fault System; Anaconda And Blue Veins (Horesetail Veins). Steward - Northeast-Striking Normal Faults, Apparent Offset Is Left Lateral, Are Slightly Mineralized. Rarus - N45e, Dip 45nw, With Apparent Dip-Slip Movement (Gravity). Middle Fault System - Strike Slightly Northeast, Dip Steeply South, Normal Faults, No Ore Associated, But Mineralized With Calcite. Continental Fault System - North-Striking Normal Fault, Displacement Approx. 1,500 Ft At A Minimum, Is Post-Ore. Veins: East-West Striking Anaconda Veins, Northwest-Striking Blue Fault Veins, The Anaconda Veins Strike N60-70e In The Western Part Of The District, Dip Steeply North To The North But Overturn With Increasing Depth To Dip South Below The 2,800 Ft Level, They Converge To The West And Downward, And The Dips Flatten Out At The Deeper Levels. To The East, The Anaconda Veins? Strike Changes To The East And The Southeast. The Anaconda Veins Then Disappear In The Central Zone And Re-Appear Several Thousand Feet Eastward. Most Of The Vein Ore Mined In Butte Came From The Anaconda Veins. The Blue Fault Veins Offset The Anaconda Veins In A Left-Lateral Sense. They Dip Steeply South (With Some Local North Dips) In The North Part Of The District And Diminish To As Little As 45 Degrees In The South Part. Mineralization Began In The Anaconda Veins And Then The Blue Veins Became Available For Mineralization. Ore Shoots On The Anaconda Veins Are In The Dialational Zone Where The Veins Change Strike Because Of Offset By The Blue Faults. Horsetail Zones ?Break Off? Of The Anaconda Veins In The Eastern Part Of The District. These Are Small Veinlets That ?Finger Out? According To Perry, Into A Spray At Nearly Right Angles To The Main Vein. Sometimes They Are The Terminus Of The Vein.

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References

Reference (Geology): Rusk B, Reed M 2002 - Scanning electron microscope-cathodoluminescence analysis of quartz reveals complex growth histories in veins from the Butte Porphyry Copper deposit, Montana: in Geology v30 pp 727-73

Reference (Geology): Rusk B G, Reed M H, Dilles J H and Kent A J R, 2006 - Intensity of quartz cathodoluminescence and trace-element content in quartz from the porphyry copper deposit at Butte, Montana : in American Mineralogist v91 pp 1300-1312

Reference (Geology): Rusk, B.G., Reed, M.H., Dilles, J.H., and Bodnar, R.J., 2000, Magmatic fluid evolution from an ancient magmatic-hydrothermal system: The porphyry copper-molybdenum deposit, Butte, MT: Geological Society of America Abstracts with Programs, v. 32, no. 7, p. 399.
Pages: 399

Reference (Production): Denver Equipment Co. Modern Mineral Processing Flowsheets. Denver Equip Co, Denver, Co, 1962.

Reference (Reserve-Resource): Asarco Inc., 1993 Annual Report, P.A15-A18.

Reference (Deposit): Miller,Richard N. Production History Of The Butte District And Geological Function, Past And Present. In Guidebook For The Butte Field Meeting Of Society Of Economic Geologists,Butte,Montana, August 18-21,1973, Pp. F1-F10

Reference (Deposit): Mcwilliams,John R. Mining Methods And Costs At The Anaconda Company Berkeley Pit, Butte,Montana. Bumines Ic 7888,1959,46pp.

Reference (Deposit): Meyer,Charles, Edward P.Shea,Charles C.Goddard Jr., And Staff,The Anaconda Company. Ore Deposits At Butte Montana. In Ore Deposits Of The United States, 1933-1967, V.11,1968, Pp. 1375-1416.

Reference (Deposit): Rocky Mountain Pay Dirt, Epa Presents Its Plan For Cleaning Up Butte'S Berkeley Pit, 2/94, P 18a.

Reference (Deposit): Young,P.M. Berkeley Pit-Servicing Mobile Equipment. Mining Engeneering Magazine, March 1959., Pp. 300b- 300d.

Reference (Deposit): Wraith, William Jr., And Fulmor,T.G.,Anaconda Company'S Butte Concentrator. Min. Eng. May 1964, Pp. 55-78

Reference (Deposit): Weed, W.H. Geology And Ore Deposits Of The Butte District, Montana.Us.Geological Survey Professional Paper 74., 265 Pp.

Reference (Deposit): Proffett, John M. Structure Of The Butte District,Montana. Guidebook For The Butte Field Meeting Of Society Ofeconomic Geologists,Butte, Montana,Aug.18-21, 1973,Pp. G1-G12.

Reference (Deposit): United States Security Exchange Commision. Anacondacompany Proxy Statement For A Special Meeting Ofcompany Proxy Statement For A Special Meeting Of Shareholders To Be Held October 20, 1976, Spet.14, 1976, 104pp.

Reference (Deposit): O'Leary,V.D. Recent Developments Underground At Butte, Min. Eng.,November, 1963, Pp. 39-43

Reference (Deposit): Popoff,C.C. Block Caving At Kelly Mine, The Anaconda Company Butte, Montana.Bumines Ic 7758, Sept.1956, 102pp.

Reference (Deposit): U.S.Congress. Closure Of Undergground Copper Mines. Hearingbefore The Subcommettee On Minerals, Materials, And Fuels Of The Committee On Interior And Insular Affairs, United States Senate To Review The Anaconda Company'S Plan To Close Its Underground Copper Mines In Butte, Montana. 93rd Congress, 2nd Session, November 25,1974 ,123pp.

Reference (Deposit): Thompson,Byrl T. Distribution Of Primary Mineralization And Hydrothermal Alteration Within The Berkeley Pit, Butte District, Montana. In Guidebook For The Butte Field Meeting Of The Soc. Of Econ.Geol.,Butte,Montana,Aug.18-21, 1973, Pp. L1-L7.

Reference (Reserve-Resource): Singer, D.A., Berger, V.I., and Moring, B.C., 2008, Porphyry copper deposits of the world: database and grade and tonnage models, 2008: U.S. Geological Survey Open-File Report 2008-1155, 45 p. http://pubs.usgs.gov/of/2008/1155/
URL: http://pubs.usgs.gov/of/2008/1155/

Reference (Deposit): Huttl,J.B.,New Crushing-Conveying Plant Designed At Berkeley, Eng.Min.J.,V.158,No.12,December, 1957, Pp.102-103.

Reference (Deposit): Mcclave,Micheal A. Control And Distribution Of Supergene Enrichment In The Berkeley Pit, Butte District,Montana In Guidebook For The Butte Field Meeting Of Soc. Of Economic Geologiists, Butte,Montana, Aug.18-21, 1973, Pp.K1-K4

Reference (Deposit): Huttl,J.B.,Berkeley Pit Maintenence Area Is Planned For Efficiency. Eng.Min.J.,V.158,No.12, March 1958, Pp.110-113

Reference (Deposit): Hannifan,Martin K. Merits Of Open Pit Vs.Underground Mining In Butte. Min..Cong.J.,April 1972, Pp.119-123.

Reference (Deposit): Huttl,J.B. Berkeley Pit Blasting Is An Art. Eng.Min.J.,V.158 No.12, December 1957, Pp.107-110.

Reference (Deposit): Mont. Bureau Of Mines And Geol. Bulletin 129, 1991,

Reference (Deposit): Goddard,Charles C.,Jr. Berkeley Pit History And Geology. Min Eng.,March 1959, Pp.290-292.

Reference (Deposit): Gustafson,Donald,L, Distribution,Minerology,And Structural Features Of The Horsetail Ore Bodies, Butte District, Montana. In Guide Book For The Butte Field Meeting Of Soc.Of Econ.Geol.,Butte Montana, August 18-21,1973 Pp.J1-J5.

Reference (Deposit): Kirkpatrick, Dave. Arco, Epa Balk At Drilling Test Wells. Montana Standard, June 26, 1992.

Reference (Deposit): Ralph.F. Berkeley Pit. Crushing And Conveying System. Min.Eng.,March 1959, Pp. 298-300a.

Reference (Deposit): Eilertson,Nils A. Estimating Direct Costs Of Development In A Block Caving Mine. Bumines Ic 8673,1975, 109pp.

Reference (Deposit): Thomas,Richard A. Montana'S Giant Berkeley Pit Girds For Another 22 Years. Surface Mining,1977 Eng.Min.J., June 1977 Pp. 107-109.

Reference (Deposit): Bennett,Harold J.,Lyman Moore,Lawrence E.Welborn, And Joseph E.Toland. An Economic Appraisal Of The Supply Of Copper From Primary Domestic Sources, Bumines Ic 8598, 1973,156pp.

Reference (Deposit): Bonner,E.O. Berkeley Pit-Mining Plan Operations. Min.Eng.,March 1959, Pp.293-297.

Reference (Reserve-Resource): Asarco Inc., Form 10-K. Dec. 31, 1995.

Reference (Deposit): Dougherty,John F. Berkeley Pit Planning. Paper Presented At The National Western Min.Conf.Of The Colorado Min. Assoc.,Denver,Colorado,Feburary 5,1965.

Reference (Deposit): Spindler,John C. The Clean Up Of Silver Bow Creek. Min.Cong.J. June 1977, Pp. 58-63.

Reference (Deposit): Shea,E.P. Development And Planning Of The Berkeley Pit.Min. Cong.J. V.43,No.7, July 1957, Pp.36-39.

Reference (Deposit): Tilman, Raymond V., Montana Resources Succeeds In Butte Through United Efforts, Pay Dirt, 5/90, Pp. 5b,6b.

Reference (Deposit): Southwestern Pay Dirt, Mri Improves Moly Extraction From Copper Ores At Butte, 6/91, P 22a.

Reference (Deposit): Sales,T.H.And C. Meyer. Priliminary Study Of Vein Formation, Butte,Montana. Econ.Geol.,V.44, No.6, 1949, Pp.465-484

Reference (Deposit): Sales,T.H. Ore Deposits At Butte Montana. Trans.Aime,V.46, 1914, Pp. 3-109.

Reference (Deposit): Dayton, Stanley H., Montana Resources- Richest Hill Once Again Yielding Copper Treasure, Engineering And Mining Journal, 1/90, Pp. C58-C65.

Reference (Deposit): Read,Ransom F. Butte Copper-Berkeley Open Pit Mine And Underground, Butte,Montana.Bumines Mas Report, Jan. 1980 23pp.

Reference (Deposit): Mining Record, Asarco Buys Interest In Montana Copper Mine, 5/10/89, P.1,2.

Reference (Deposit): Miner'S News, Asarco Inc. Joins Montana Resources In Copper Venture, 6/89, P6b.

Reference (Deposit): Hansen, C.J., Going Good In Butte, Pay Dirt, 9/89, P.24b.

Reference (Deposit): Dayton,Stanley. Anaconda Maps Greatest Expansion Program In The History Of Butte. Min.World.V.18,No.12,November 1956, Pp.56-61

Reference (Age): Lund, K., Aleinikoff, J.N., Kunk, M.J., Unruh, D.M., Zeihen, G.D., Hodges, W.C., du Bray, E. A. and O'Neill, J.M., 2002, SHRIMP U-Pb and 40Ar/ 39Ar age constraints for relating plutonism and mineralization in the Boulder Batholith region, Montana; Economic Geology, v. 97, p. 241-267.

Reference (Reserve-Resource): Mining Journal-various years

Reference (Deposit): Brimhall,George,H.,Jr. Minerology, Texture, And Chemistry Of Early Wallrock Alterations In The Deep Underground Mine And Continental Area, Butte District,Montana. In Guide-Book For The Butte Field Meeting Of Soc.Of Econ.Geol., Butte Montana,August 18-21,1973 Pp.H1-H4.

Reference (General): Kirkham, R.V. and Sinclair, W.D., 1996, Porphyry copper, gold, molybdenum, tungsten, tin, silver; in Eckstrand, O.R., Sinclair, W.D. and Thorpe, R.I., eds., Geology of Canadian Mineral Deposit Types, Geological Survey of Canada, Geology of Canada, no. 8, p. 421-446.

Reference (Geology): The portergeo.com.au web page for "Butte, Continental, Berkely, Anaconda Vein" has a long description of the geology.

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Principal Gold Districts of Montana

In Montana, 54 mining districts have each have produced more than 10,000 ounces of gold. The largest producers are Butte, Helena, Marysville, and Virginia City, each having produced more than one million ounces. Twenty seven other districts are each credited with between 100,000 and one million ounces of gold production. Read more: Principal Gold Districts of Montana.