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Florence

Prospect in Pinal county in Arizona, United States with commodities Copper, Copper Oxide, Copper Sulfide, Molybdenum
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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. Mineral occurrence model information
  9. Host and associated rocks
  10. Nearby scientific data
  11. Ore body information
  12. Controls for ore emplacement
  13. Economic information about the deposit and operations
  14. Mining district
  15. Mineral rights holdings
  16. Land status
  17. Ownership information
  18. Reserves and resources
  19. Workings at the site
  20. Links to other databases
  21. Bibliographic references
  22. General comments
  23. Reporter information

Geologic information

Identification information

Deposit ID 10186598
MRDS ID W002694
MAS/MILS ID 0040210007
Record type Deposit
Current site name Florence
Alternate or previous names Florence Conoco, Continental Oil Company Florence, Poston Butte, Florence Copper Mine, Conoco Copper Deposit, Aztec Exp. and Devel Co Property, Poston Butte Prospect, Dollar Pit

Geographic coordinates

Point of reference Ore Body
Geographic coordinates: -111.43072, 33.04785 (WGS84)
Elevation 475
Location accuracy 100(meters)
Relative position 2 km WSW of Poston Butte. Location is for the center of the proposed 2000-3000 well field for in-situ leaching shown on Brown and Caldwell/BHP aerial photo in press release.

Site location context

Political divisions (FIPS codes)

Pinal(county)

Arizona(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Florence(quadrangle 1:24,000 scale)

Mesa(quadrangle 1:100,000 scale)

Mesa(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Middle Gila(hydrologic unit)

Middle Gila(hydrologic accounting unit)

Middle Gila(hydrologic subregion)

Lower Colorado(hydrologic region)

Geographic areas

Country State County
United States Arizona Pinal

Commodities

Commodity Importance
Copper Primary
Copper Oxide Primary
Copper Sulfide Primary
Molybdenum Secondary

Materials information

Materials Type of material
Brochantite Ore
Chalcocite Ore
Chrysocolla Ore
Copper Ore
Cuprite Ore
Azurite Ore
Molybdenite Ore
Shattuckite Ore

Alteration

  • (Local) Hydrothermal, oxidation, potassic
  • (Local) sericitization, kaolinization, propylitic

Mineral occurrence model information

Model code 58
USGS model code 18a
Deposit model name Porphyry Cu, skarn-related
Mark3 model number 9

Host and associated rocks

  • Host or associated Host
    Rock type Plutonic Rock > Granitoid > Quartz Monzonite
  • Host or associated Associated
    Rock type Plutonic Rock > Granitoid > Granodiorite
    Stratigraphic age (youngest) Paleocene
    Chronological age 62

Nearby scientific data

Ore Body (1) -111.43072, 33.04785
ListMap

Economic information

Ore body information

  • Thickness 503M
    Length 0M
    Width 0M
    Area 2100HA
    Depth to top 107M
    Field Value
    Type of Orebody #1 DISSEMINATED
    Shape of Orebody #1 MASSIVE
    Type of Orebody #2 REPLACEMENT
    Primary mode of Origin HYDROTHERMAL
    Secondary mode of Origin OXIDATION
    Primary Ore Control FRACTURING
    Type of Wallrock Alter. #1 SERICITIC
    Type of Wallrock Alter. #2 POTASSIC
    Avg. Thick. Unconsol. Mat. 107
    Total Surface Area (HA) 2100
    Date of Last Modification 910905

Controls for ore emplacement

  • Fracturing, Brecciation

Comments on the geologic information

  • SHATTUCKITE IS ALSO PRESENT.
  • ANDESITE INTRUDES THE GRANITE. THE QUARTZ MONZONITE WAS EMPLACED INTO PREC HOST ROCKS.

Economic information about the deposit and operations

Operation type Surface
Development status Prospect
Commodity type Metallic
Deposit size Large
Significant Yes
Discovery year 1969
Mining method Open Pit
Milling method Flotation

Mining district

District name Blackwater District

Mineral rights holdings

Type of mineral rights Located Claim
Type of mineral rights Other
Type of mineral rights State Lease

Land status

Ownership category Unknown
Ownership category Private
Ownership category State

Ownership information

  • Type Owner-Operator
    Owner Magma Copper Co.
    Interest 100
    Home office 7400 N. Oracle Rd., Tucson, Az 85704
    Year 1993
    First year 1992
    Last year 1996
  • Type Owner
    Owner Broken Hill Proprietary Co. Ltd.
    Home office Australia
    Year 1996
    First year 1996
  • Type Owner-Operator
    Owner Continental Oil Co-Conoco
    Interest 100
    Home office Colorado
    Year 1980
    Last year 1992
  • Type Owner-Operator
    Owner BHP Billiton
    Interest 100
    Home office London, UK
    Year 1998
    First year 1998
  • Type Owner-Operator
    Owner Florence Copper
    Interest 100
    Home office Arizona
    Year 2001
    First year 2001

Comments on the production information

  • DEPOSIT HAS BEEN A MINOR PRODUCER

Reserves and resources

  • Type In-situ
    Estimate year 1996
    Reserves 730000000mt ore
    Remarks 2775000 mt of Cu, and 58,400 tonnes molybdenum contained.
  • Type In-situ
    Estimate year 1989
    Reserves 725000000mt ore
    Commodity Subtype Grade units Group Importance Year
    Copper Cu 0.4 wt-pct Copper Primary 1989
  • Type In-situ
    Name oxide ore
    Estimate year 1994
    Indicated 333990000
    Remarks Magma Copper 1994 10K.
    Commodity Subtype Grade units Group Importance Year
    Copper Cu 0.34 wt-pct Copper Primary 1994
  • Type In-situ
    Estimate year 1978
    Reserves 450000000mt ore
    Commodity Subtype Grade units Group Importance Year
    Copper Cu 0.39 wt-pct Copper Primary 1978
  • Type In-situ
    Estimate year 1977
    Total resources 362811000mt ore
    Commodity Subtype Grade units Group Importance Year
    Copper Sulfide Cu 0.32 wt-pct Copper Primary 1977
    Copper Oxide Cu 0.39 wt-pct Copper Primary 1977
  • Type In-situ
    Estimate year 1972
    Total resources 226757000mt ore
    Commodity Subtype Grade units Group Importance Year
    Copper Cu 0.5 wt-pct Copper Primary 1972
  • Type In-situ
    Name sulfide ore
    Estimate year 1994
    Indicated 300000000mt ore
    Remarks Magma Copper 1994 10K.
    Commodity Subtype Grade units Group Importance Year
    Copper Cu 0.39 wt-pct Copper Major 1994

Comments on the reserve resource information

  • DEMONSTRATED RESOURCE IS COMPOSED OF SULFIDE AND OXIDE AS FOLLOWS: SULFIDE- 450,000,000 MT @ 0.39% CU OXIDE- 270,000,000 MT @ 0.37% CU OTHER NAME:POSTON BUTTE. DEMO RESOURCE AS OF 12/31/94: SULFIDE- 299,000,000 MT @ .34% CU OXIDE - 334,000,000 MT @ .39% CU TOTAL 633,000,000 MT @ .36% CU
  • ORE (.5% CU, 90% RECOVERY)

Workings at the site

  • Type of workings Surface
    Area 520HA
    Field Value
    MAS Development Schedule # 1
    Mining Record # 1
    Status of Mining Method PROPOSED
    Mining Method OPEN PIT
    Avg. Overburden Thickness 115
    Hardness of Ore HARD ROCKS
    Avg. Bench Height (meters) 15
    Capacity 27216
    Capacity Units MT ORE/DAY
    Preprod. Stripping Vol. 29223
    Unit Production Cost 2.44
    Units of Production $/MT ORE
    Operating Days per Year 357
    Operating Shifts per Day 3
    Year of Information 1978
  • Type of workings Surface
    Area 520HA
    Field Value
    MAS Development Schedule # 1
    Mining Record # 2
    Status of Mining Method PROPOSED
    Mining Method OPEN PIT
    Hardness of Ore HARD ROCKS
    Avg. Bench Height (meters) 15
    Capacity 45370
    Capacity Units MT ORE/DAY
    Unit Production Cost 2.34
    Units of Production $/MT ORE
    Operating Days per Year 357
    Operating Shifts per Day 3
    Year of Information 1978
  • Type of workings Surface
    Area 520HA
    Field Value
    MAS Development Schedule # 1
    Mining Record # 3
    Status of Mining Method PROPOSED
    Mining Method OPEN PIT
    Hardness of Ore HARD ROCKS
    Avg. Bench Height (meters) 15
    Capacity 27216
    Capacity Units MT ORE/DAY
    Unit Production Cost 2.44
    Units of Production $/MT ORE
    Operating Days per Year 357
    Operating Shifts per Day 3
    Year of Information 1978

Comments on development

  • PREVIOUSLY OWNED BY CONOCO. AZTEC EXPLORATION AND DEVELOPMENT WAS THE OPERATOR IN 1970.

Reference information

Bibliographic references

  • Other Database

    CIMRI

  • Deposit

    SKILLINGS MINING REVIEW, CONTINENTAL OIL DISCOVERS COPPER MINERALIZATION IN ARIZONA, VOL. 59, NO. 44. OCTOBER 31, 1970 PP. 11. (MILS,UNDER,EXPLO,ASSAY,RESRV)

  • Reserve-Resource

    MAGMA COPPER CO. 1993 ANNUAL REPORT. P. 9.

  • Geology

    Mining Engineering, May issue, p. 72. Nason, P.W., Shaw, A.V. and Aveson, K.D., 1982, Geology of the Poston Butte porphyry copper deposit

  • Production

    Niemuth, N.J., 1998, Arizona

  • Development

    Brown and Caldwell Environmental Engineering and Consulting, Mine Characterizing and Permitting, BHP-Copper, Florence Site, Arizona: press release discussing the permitting process for the proposed Florence in-situ leach mine. Accessed 9/28/2010
    http://www.brownandcaldwell.com/PAGs%5CP_522_0800a_BHPMine.pdf

  • Deposit

    PAY DIRT, CONOCO PUTS FLORENCE COPPER PROJECT ON BACK BURNER NO.449. NOVEMBER 22, 1976. PP. 7. (ASSAY,RESRV,ENVIR,UNDER,BENEF-PRO,COMMOD)

  • Reserve-Resource

    MAGMA COPPER CO., 1994 10-K, P.20.

  • Geology

    Pinal County, Arizona; in Titley, S. R., ed., Advances in Geology of the Porphyry Copper Deposits, Southwest North America, University of Arizona Press, Tucson, Arizona, p. 375-385.

  • Deposit

    CONOCO ANNUAL REPORT. 1972 . PP. 29.

  • Deposit

    SKILLINGS MINING REVIEW,CONOCO EVALUATION OF FLORENCE COPPER

  • Deposit

    WORLD MINING, VOL. 27, NO. 13. NOVEMBER 1974. PP. 74.

  • Deposit

    ARUNDALE, J.C. MONTHLY LIAISON REPORT FOR THE STATE OF ARIZ.

  • Deposit

    SKILLINGS, D. N. JR. ARIZONA CONFERENCE OF A.I.M.E. ANNUAL

  • Deposit

    AMERICAN METAL MARKET. DUPONT MOVING PLANS TO SELL CONOCO

  • Deposit

    INTERMOUNTAIN PAY DIRT. CONOCO GETTING OUT OF MINERALS

  • Deposit

    NASON, PHILIP W., UNIV OF AZ PRESS, 1982, P.375.

  • Deposit

    DILLARD, GARY, SW PAY DIRT, 8-92, P.3A.

  • Deposit

    MINING JOURNAL, 8-7-92, V319 N8185, P.88.

  • Deposit

    MAGMA COPPER COMPANY 1993 10-K, P.18.

  • Deposit

    MINING RECORD, 1974, ARIZONA COPPER PROJECT NEAR COMPLETION: PROJECT MANAGER NAMED.

  • Deposit

    SAWYER, M.B., GURMENDI, A.C., DALEY, M.R., AND HOWELL, S.B., 1992, PRINCIPAL DEPOSITS OF STRATEGIC AND CRITICAL MINERALS IN ARIZONA: UNITED STATES BUREAU OF MINES SPECIAL PUBLICATION, 334 P.

  • Deposit

    YEEND, 1976, USGS MAP MF-778.

  • Deposit

    WILSON, 1969, ABM BULL 179.

  • Deposit

    ABGMT FILE DATA.

  • Deposit

    ULLMER, 1978, JOURNAL OF GEOCHEMICAL EXPLORATION, V. 9, NO. 2-3, P. 235-236.

  • Deposit

    ADMR CONTINENTAL OIL CO(FLORENCE PROJECT)ACTIVE FILE
    SKILLINGS MINING REVIEW CONOCO OIL DISCOVERS CU MIN. IN AZ VOL 59 NO 44,VOL 65 NO 3,VOL 66 NO 1

General comments

Subject category Comment text
Deposit ADDITIONAL COMMODITIES ARE MO, AU AND AG. ENVIRONMENTAL - SEVERE WATER PROBLEMS DUE TO THE MINE LOCATION BEING DIRECTLY ADJACENT TO THE GILA RIVER HAVE RESTRICTED DEVELOPMENT. LOCAL AGRICULTURE INTERESTS FEAR A REDUCTION IN THE WATER TABLE DUE TO LARGE SCALE MINE DEWATERING OPERATIONS. ACCOMMODATIONS FOR MINE DE- WATERING MUST BE MADE WITH THE SAN CARLOS PROJECT WHICH ADMINISTERS LOCAL IRRIGATION. FIVE WATER WELLS HAVE BEEN DRILLED FOR HYDROLOGICAL TESTING. GEOLOGY - DEPOSIT IS A PORPHYRY WHICH CONTAINS COPPER OXIDE ORE ON TOP OF COPPER SULFIDE ORE. SULFIDE MINERALIZATION EXTENDS TO 2000 FEET. RESERVES-MATRIX 1 AND 2 REPRESENT OXIDE ORE AND MATRIX 3 REPRESENTS SULFIDE ORE. SURFACE - FUTURE PLANS CALL FOR THE DEVELOPMENT OF A 30,000 TPD (27,216MT/D) OPEN PIT AS A STEP TOWARD THE ULTIMATE PRODUCTION OF 50,000 TPD (45,370 MT/D). ONLY OXIDE ORE WILL BE MINED THE FIRST FEW YEARS. PRODUCT - PILOT PLANT OPERATIONS HAVE SHOWN THE PROCESSES TESTED TO TREAT SULPHIDE AND OXIDE ORES TO BE VIABLE. ONLY OXIDE ORE WOULD BE TREATED THE FIRST YEARS TRANSPORTATION - MINE AND PLANT ARE WITHIN TWO MILES OF A MAJOR RAILROAD LINE OF THE SOUTHERN PACIFIC. COST RELATED INFORMATION: PILOT PROGRAM DEVELOPMENT STARTED IN MID-1974. IT WAS DESIGNED TO BE A 30 MONTH PROGRAM COSTING AN ESTIMATED $25 MILLION. THE PROGRAM INCLUDED THE SINKING OF TWO 72 IN 700 FOOT SHAFTS; MINING OF LARGE BULK SAMPLES OF OXIDE AND SULFIDE ORE; CONSTRUCTION AND OPERATION OF A PILOT PLANT, ADDITIONAL DRILLING AND GEOLOGICAL STUDIES; MINE PLANNING AND PIT DESIGN; HYDROLOGICAL TESTS; AND ENVIRONMENTAL STUDIES. THE PILOT PLANT WAS DESIGNED TO BE A PERMANENT METAL- LURGICAL DEVELOPMENT FACILITY. THE PROJECT WAS SHELVED IN LATE 1976 FOR AN INDEFINITE PERIOD. AT THAT POINT IN TIME, MORE THAN $30 MILLION HAD BEEN INVESTED IN LAND ACQUISITION, EXPLORATION DRILLING, ENGINEERING DESIGN AND ENVIRONMENTAL AND MARKETING STUDIES DEVELOPMENT WAS POSTPONED BECAUSE THE COSTS OF THE FLORENCE DEPOSIT WERE JUDGED TO BE HIGHER THAN MANY OTHER EXPLORED DEPOSITS WITHIN THE INDUSTRY. THE PROJECT NOW AWAITS REEVALUATION AT AN APPROPRIATE FUTURE TIME.

Reporter information

Type Date Name Affiliation Comment
Reporter 02-OCT-96 Br U.S. Bureau of Mines
Reporter 04-NOV-83 ADMR U.S. Bureau of Mines
Reporter 01-MAY-74 Cox, Dennis P. U.S. Geological Survey
Updater 01-NOV-93 Orris, Greta J. U.S. Geological Survey
Updater 12-SEP-94 Orris, Greta J. U.S. Geological Survey
Updater 27-JUL-09 Anderson, Claire U.S. Geological Survey
Editor 29-SEP-10 Schruben, Paul U.S. Geological Survey Revised reserves.

Beyond USGS

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

Maps centered on this site

Authoritative Arizona resources

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