Pima Open Pit Mine

Producer in Pima county in Arizona, United States with commodities Copper, Molybdenum, Silver, Zinc, Lead, Gold

Geologic information

Identification information

Deposit ID 10039593
MRDS ID M050388
Record type Site
Current site name Pima Open Pit Mine
Related records 10113722

Geographic coordinates

Geographic coordinates: -111.07319, 31.98651 (WGS84)
Elevation 1018
Relative position 17 MI SE OF TUCSON.
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Geographic areas

Country State County
United States Arizona Pima

Public Land Survey System information

Meridian Township Range Section Fraction State
Gila and Salt River 016S;017S 012E;012E 36;01 S2 (36); N2 (01) Arizona

Commodities

Commodity Importance
Copper Primary
Molybdenum Secondary
Silver Secondary
Zinc Tertiary
Lead Tertiary
Gold Tertiary

Comments on the commodity information

  • MAGNETITE LOCALLY QUITE MASSIVE IN TACTITES, COMMONLY ASSOCIATED W ITH BLACK OR GREEN SERPENTINE

Materials information

Materials Type of material
Bornite Ore
Chalcocite Ore
Chalcopyrite Ore
Chrysocolla Ore
Cuprite Ore
Galena Ore
Hematite Ore
Magnetite Ore
Malachite Ore
Molybdenite Ore
Sphalerite Ore
Tennantite Ore
Tenorite Ore
Serpentine Gangue

Alteration

  • (Local) Propylitic, Quartz-Sericite, Potassic, Skarn

Analytical data

Result CU ABOUT 1% IN TACTITE ZONE. 1976--AVERAGE ORE GRADE 0.47% CU AND 0 .015% MO.

Mineral occurrence model information

Model code 58
USGS model code 18a
Deposit model name Porphyry Cu, skarn-related
Mark3 model number 9
Model code 85
USGS model code 22c
Deposit model name Polymetallic veins
Mark3 model number 46

Host and associated rocks

  • Host or associated Associated
    Rock type Volcanic Rock (Aphanitic) > Felsic Volcanic Rock > Rhyolite
    Rock unit name Ruby Star Granodiorite;
    Rock description Ruby Star Granodiorite;
  • Host or associated Host
    Rock type Sedimentary Rock > Clastic Sedimentary Rock > Arkose
  • Host or associated Host
    Rock type Sedimentary Rock > Carbonate > Limestone
    Rock unit name Colina Limestone, Epitaph Formation, Scherer Formation, Concha Li Mestone, All Of Naco Group;Whitcomb Quartzite, Angelica Arkose;Rodolfo Formation
    Rock description Colina Limestone, Epitaph Formation, Scherer Formation, Concha Li Mestone, All Of Naco Group;Whitcomb Quartzite, Angelica Arkose;Rodolfo Formation

Nearby scientific data

(1) -111.07319, 31.98651

Geologic structures

Type of structure Local
Structure description Ew Post Mineralization Faulting, Jointing, San Xavier Thrust

Ore body information

  • General form TABULAR
    Strike ABOUT E-W
    Dip ABOUT 455
    Thickness 182.88M
    Depth to bottom 243.84M
    Depth to top 60.96M
    Width 487.68M
    Length 487.68M

Controls for ore emplacement

  • Pre Ore Brecciation & Stockwork Fracturing, Wall Rock Lithologies. Sulfides Preferentially Replaced Calc-Magnesian Silicates

Comments on the geologic information

  • MOLYBDENUM MORE IMPORTANT IN PORPHYRY AND ARKOSE.

Economic information

Economic information about the deposit and operations

Development status Producer
Commodity type Metallic
Deposit size Large
Significant Yes
Discovery year 1950
Discovery method Geophysical Anomaly
Year of first production 1952

Mining district

District name Pima District

Ownership information

  • Type Owner-Operator
    Owner Asarco (American Smelting And Refining Co.)
    First year 1988

Reserves and resources

  • Type In-situ
    Estimate year 1967
    Total resources 294,784,000mt ore
    Commodity Subtype Grade units Group Importance Year
    Copper Cu 0.48 wt-pct Copper Major 1967
  • Type In-situ
    Estimate year 1971
    Total resources 122,902,000mt ore
    Commodity Subtype Grade units Group Importance Year
    Copper Cu 0.49 wt-pct Copper Major 1971
    Molybdenum Mo 0.015 wt-pct Molybdenum Minor 1971
  • Type In-situ
    Estimate year 1983
    Total resources 54,784,000mt ore
    Commodity Subtype Grade units Group Importance Year
    Copper Cu 0.482 wt-pct Copper Major 1983

Workings at the site

  • Type of workings Surface
    Overall length 1524M
    Overall width 914.4M

Comments on development

  • OPEN PIT CAME INTO PRODUCTION IN 1956. PREVIOUS OWNERS INCLUDE UNION OIL, CYPRUS MINES, UTAH MINING AND CONSTRUCTION.

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Mineral Resources Data System MRDS M050388
U.S. Bureau of Mines Minerals Availability System MAS 0040190006

Bibliographic references

  • Deposit

    HIMES, 1972, AIME ANN MTG REPORT NO 72-I-57.

  • Deposit

    COOPER, 1960, USGS BULL 1112.

  • Deposit

    CREASEY & KISTLER, 1962, USGS PP 450-D.

  • Deposit

    HUFF, 1970, USGS BULL 1312-C.

  • Deposit

    LACY & TITLEY, 1959, SO. AZ. GUIDEBOOK II.

  • Deposit

    THURMOND,R., AND OTHERS, 1954, PIMA - A THREE PART STORY. GOLOGY, OPEN PIT, MILLING: MINING ENGINEERING, V. 10.

  • Deposit

    USBM FILE DATA

  • Deposit

    KEITH, 1974, ABM BULL 189, P. 137

  • Deposit

    MAUGER, 1966, PHD THESIS, UNIV OF AZ

  • Deposit

    LANGLOIS, 1978, AZ GEOL SOC DIGEST VII, P. 103-113

  • Deposit

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

  • Other Database

    CIMRI

  • Reserve-Resource

    MINING ENGINEERING, 1967; SAWYER AND OTHERS, 1992.

General comments

Subject category Comment text
Deposit ORE BODY CUT OFF AT DEPTH BY SAN XAVIER THRUST, WHICH CUTS HELMUT FANGLOMERATE (28-30 M.Y.). BRECCIA PIPE PRESENT.
Deposit THIS REPORT REPRESENTS A MERGER OF ORIGINAL RECORD M050388 WITH RECORD W002678 OF JAN WILT AND RECORD D000332 OF ROBERT KING IN MOLYBDENUM FILE, CONTACT PERSON T.G. THEODORE, USGS. PIMA HAS BECOME PART OF THE MISSION COMPLEX. SEE RECORD MO5O387. ; INFO.SRC : 1 PUB LIT; 2 UNPUB REPT
Deposit SEE MISSION COMPLEX.

Reporter information

Type Date Name Affiliation Comment
Reporter 01-MAR-1983 Peterson, Jocelyn A. U.S. Geological Survey
Updater 01-DEC-1993 Orris, Greta J. U.S. Geological Survey