Esperanza

The Esperanza is a molybdenum and copper mine located in Pima county, Arizona at an elevation of 4,199 feet.

About the MRDS Data:

All mine locations were obtained from the USGS Mineral Resources Data System. The locations and other information in this database have not been verified for accuracy. It should be assumed that all mines are on private property.

Mine Info

Satelite View

MRDS mine locations are often very general, and in some cases are incorrect. Some mine remains have been covered or removed by modern industrial activity or by development of things like housing. The satellite view offers a quick glimpse as to whether the MRDS location corresponds to visible mine remains.

Site Name

Primary: Esperanza
Secondary: Esperanza Sierrita
Secondary: Old New Year's Eve Shaft
Secondary: West Esperanza
Secondary: Sierrita
Secondary: Amargosa
Secondary: Matt Mcgee

Commodity

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

Location

State: Arizona
County: Pima
District: Pima District

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.

Holdings

Not available

Workings

Type: Surface

Ownership

Owner Name: Cyprus Sierrita Corp.
Years: 1988 -

Production

Year: 1986
Material type: Copper Recovered From Leach Operation
Year: 1985
Material type: Copper Recovered From Leach Operation
Year: 1984
Material type: Copper Recovered From Leach Operation
Year: 1983
Material type: Copper Recovered From Leach Operation
Year: 1982
Material type: Copper Recovered From Leach Operation
Year: 1981
Mined: 5687000.000 mt
Material type: ore
Year: 1980
Mined: 5613000.000 mt
Material type: ore
Year: 1979
Mined: 4445000.000 mt
Material type: ore
Year: 1978
Material type: ore
Year: 1977
Year: 1976
Year: 1968
Material type: MO
Description: Ap_Grade: ^0.036% Mo
Year: 1968
Material type: CU
Description: Ap_Grade: ^0.35% Cu

Deposit

Record Type: Deposit
Operation Category: Past Producer
Operation Type: Unknown
Year First Production: 1959
Year Last Production: 1986
Discovery Year: 1895
Discovery Method: Ore-Mineral In Place
Years of Production:
Organization:
Significant: Y
Deposit Size: L

Physiography

General Physiographic Area: Intermontane Plateaus
Physiographic Province: Basin And Range Province
Physiographic Section: Sonoran Desert

Mineral Deposit Model

Not available

Orebody

Form: OVATE, MASSIVE

Structure

Type: L
Description: Broad Nw Trending Shear Zone. Faults Trending Ne-Ene, Dip Nw & Se; Nw-Nnw, Dip Ne & Sw; N-S, Dip E & W

Alterations

Alteration Type: L
Alteration Text: Clay (Moderate To Intense), Quartz-Sericite-K Feldspar Argillation, Silication, Biotite

Rocks

Name: Quartz Latite
Role: Associated
Age Type: Associated Rock
Age Young: Pliocene

Analytical Data

Analytical Data: ORE GRADE HAS AVERAGED 0.5% CU AND 0.028% MO SINCE THE START OF OPERATIONS

Materials

Ore: Chalcocite
Ore: Melaconite
Ore: Malachite
Ore: Silver
Ore: Copper
Ore: Covellite
Ore: Molybdenite
Ore: Pyrite
Ore: Chalcopyrite
Ore: Ferrimolybdite
Ore: Sphalerite
Ore: Tenorite
Ore: Galena
Ore: Cuprite
Ore: Torbernite
Gangue: Magnetite
Gangue: Jarosite
Gangue: Goethite
Gangue: Limonite
Gangue: Hematite

Comments

Comment (Production): ITEMS 1-2 SIERRITA OPEN PIT.

Comment (Development): PREMINE STRIPPING BEGAN IN 1957. PREVIOUS OWNERS INCLUDE DUVAL CORP. (1979)

Comment (Workings): OPEN PIT. MEASUREMENTS OF MINED AREA ESTIMATED FROM MAP. SHUT DOWN IN EARLY 1972 FOR 1 YEAR TO REMOVE BACKLOG OF STOCKPILED CU CONCENTRATES. LEACHING OF DUMP MATERIALS.

Comment (Geology): AROUND CU-MO ORE ZONE IS AUREOLE OF VEIN DEPOSITS WORKED FOR PB, ZN, AG IN EARLY 1900'S.

Comment (Deposit): PRIMARY ORE IN QUARTZ MONZONITE, SECONDARY ORE IN ANDESITE PORPHYRY. WEST ESPERANZA BODY IS IRREGULAR SHAPE ABOUT 2000 FT BY 1800 FT. MINERALIZATION IS IN FRACTURES IN QUARTZ.

Comment (Identification): NO MINING WAS BEING DONE AT THE PROPERTY AT THE TIME OF THE VISIT IN 1978, EXCEPT THE LEACH OPERATION. PROPERTY UPDATE JUL 1987 PROPERTY COMBINED WITH SIERRITA AUGUST 1988. WHEN CYPRUS PURCHASED THE SIERRITA-ESPERANZA MINE & MILL COMPLEX THEY COMBINED THE TWO PROPERTIES AS ONE COMPLEX CALLED SIERRITA. THE RESERVES HAVE BEEN COMBINED AND THE ESPERANZA PIT IS NOW CALLED THE EAST PIT AND THE SIERRITA PIT IS CALLED THE WEST PIT. HISTORICAL DATA SETS HAVE BEEN RETAINED IN THIS DATA BASE. OPERATING PARAMETERS AND COST DATA ARE NOW PART OF THE SIERRITA DATA BASE, SEQUENCE NUMBER 0040190004. ALL ESPERANZA FILE DATA HAS BEEN TRANS- FERRED TO THE SIERRITA FILE. ONE ESPERANZA FILE HAS BEEN RETAINED TO EXPLAIN WHERE ALL OF THE ESPERANZA DATA IS LOCATED.

Comment (Identification): *****SEE Sierrita Deposit ID 10137918

References

Reference (Age): Shafiqullah, M. and Langlois, J.D., 1978, The Pima mining district, Arizona, a geochronologic update; in James, H.L., Callender, J.F., Wilt, J.C. and Clemons, R.E., eds., Land of Cochise, Southeast Arizona, University of New Mexico, Field Conference Guidebook Number 29, p. 321-327.

Reference (Age): Ruiz, J. and Mathur, R., 1999, Metallogenesis in continental margins: Re-Os evidence from porphyry copper deposits in Chile; in Lambert, D.D. and Ruiz, J., eds., Application of Radiogenic Isotopes to Ore Deposit Research and Exploration, Reviews in Economic Geology, v. 12, p. 59-72.

Reference (Deposit): SCHMIDT ET AL, 1959, SOUTHERN ARIZONA GUIDEBOOK II.

Reference (Reserve-Resource): LYNCH, 1967 (ITEMS 1-4); EMJ, 1970 (ITEM 5); WAR MINERALS REPORT 405, 1945 (ITEM 6); COX, 1973, (ITEM 7); SAWYER AND OTHERS, 1992.

Reference (Deposit): AIKEN & WEST, 1978, AZ GEOL SOC DIGEST, V. 11, P 117-128.

Reference (Deposit): COOPER, 1960, USGS BULL 1112-C.

Reference (Deposit): KEITH, 1974, ABM BULL 189, P. 135.

Reference (Deposit): LYNCH, 1967, IN TITLEY & HICKS, UNIV OF AZ PRESS, P. 267-279.

Reference (Deposit): ANDERSON, C.A., AND KUPFER, D.H., 1943, REPORT ON THE PROPERTIES OF THE AMARGOSA MOLYBDENUM AND COPPER CORP: PIMA COUNTY, ARIZONA OPEN FILE REPORT.

Reference (Deposit): WAR MINERALS REPORT, 1945, ESPERANZA PROPERTY, PIMA COUNTY, ARIZONA: WAR MINERALS REPORT 405.

Reference (Deposit): EMJ, 1970, SIERRITA MAKES IT WITH BIG EQUIPMENT: AUGUST.

Reference (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.

Reference (Deposit): EMJ, 1970, DUVAL DEDICATES THE SIERRITA OPEN PIT: JULY.

Reference (Other Database): CIMRI

Reference (Production): EMJ, JULY, 1970; FIGURE 3 FROM GSA, 1968; SAWYER AND OTHERS, 1992.

Arizona Gold

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