Tohono

Site Name

Primary: Tohono
Secondary: Cyprus Tohono
Secondary: Lakeshore
Secondary: Cyprus Casa Grande
Secondary: Casa Grande
Secondary: Treasure State
Secondary: Trans Arizona Res. Inc

---

Commodity

Primary: Copper Oxide
Primary: Copper
Primary: Copper Sulfide
Secondary: Molybdenum
Tertiary: Lead
Tertiary: Silver
Tertiary: Zinc
Tertiary: Gold
Tertiary: Silica

---

Location

State: Arizona
County: Pinal
District: Lakeshore

---

Land Status

Not available

---

Holdings

Type: Private Lease
Type: Patented
Type: Located Claim

---

Workings

Type: Underground

---

Ownership

Owner Name: Tohono O'Odham Nation
Percent: 100.0
Home Office: Arizona
Info Year: 1994

Owner Name: Freeport-McMoran Copper and Gold Inc
Percent: 100.0
Home Office: Arizona
Info Year: 2009
Years: 2007 -

Owner Name: Phelps Dodge
Percent: 100.0
Years: 1999 - 2007

Owner Name: Cyprus Amax Minerals
Percent: 100.0
Years: 1987 - 1999

Owner Name: Noranda
Percent: 100.0

---

Production

Year: 2005
Material type: From leach stockpiles. Phelps Dodge 2006 10K p. 15.
Year: 1997
Mined: 2700000.000 mt
Material type: Cyprus Amax 1997 10K p. 4.
Year: 1996
Time Period: 1976-1996
Mined: 29855000.000 mt
Year: 1996
Mined: 9000000.000 mt
Material type: Cyprus Amax 1996 10K p. 3.
Year: 1994
Mined: 4500000.000 mt
Material type: Cyprus Amax 1994 10K p. 3.
Year: 1995
Mined: 7300000.000 mt
Material type: Cyprus Amax 1995 10K p. 3.
Year: 1993
Description: Cu Prd From In-Situ Leach & Sx-Ew 136 Mt Cathode Cu
Year: 1992
Description: Cu Prd From In-Situ Leach & Sx-Ew 454 Mt Cathode Cu
Year: 1991
Year: 1991
Description: Cu Prd From In-Situ Leach & Sx-Ew 3110 Mt Cathode Cu
Year: 1990
Description: Cu Prd From In-Situ Leach & Sx-Ew 1130 Mt Cathode Cu
Year: 1989
Description: Cu Prd From In-Situ Leach & Sx-Ew 2270 Mt Cathode Cu
Year: 1988
Description: Cu Prd From In-Situ Leach & Sx-Ew 1950 Mt Cathode Cu
Year: 1987
Description: Cu Prd From In-Situ Leach & Sx-Ew 1880 Mt Cathode Cu
Year: 1986
Description: Cu Prd From In-Situ Leach & Sx-Ew 3220 Mt Cathode Cu
Year: 1985
Description: Cu Prd From In-Situ Leach & Sx-Ew 6130 Mt Cathode Cu
Year: 1984
Description: Cu Prd From In-Situ Leach & Sx-Ew 5986 Mt Cathode Cu
Year: 1983
Description: 1471 Mt Cu Produced From Ppt
Year: 1983
Description: 965640 Mt Ore Mined
Year: 1983
Description: 15547 Mt Cu Prod From Ore
Year: 1982
Description: 1471830 Mt Ore Mined
Year: 1982
Description: 20689 Mt Cathode Cu Produced
Year: 1978
Time Period: 1976-1978
Material type: Cu Leach
Year: 1981
Description: Noranda Annual Report, 1981 1767000 Short Tons Oxide Ore
Year: 1978
Time Period: 1976-1978
Material type: Cu Ore
Year: 1977
Description: Bumines Statistics 1271000 Short Tons Oxide Ore
Year: 1977
Description: Bumines Statistics 1216000 Short Tons Sulfide Ore
Year: 1976
Time Period: 1929-1976
Material type: AU
Year: 2008
Material type: From leach stockpiles. Freeport-McMoRan 2008 10K p. 21.
Year: 1976
Description: Bumines Statistics 1266500 Short Tons Oxide Ore
Year: 2006
Material type: From leach stockpiles. Phelps Dodge 2006 10K p. 15.
Year: 1998
Material type: From leach stockpiles. Cyprus Amax 1998 10K p. 4.
Year: 1976
Description: Bumines Statistics 1010899 Short Tons Sulfide Ore
Year: 2007
Material type: From leach stockpiles. Freeport-McMoRan 2008 10K p. 21.

---

Deposit

Record Type: Deposit
Operation Category: Producer
Operation Type: Underground
Mining Method: Auger Mining - Leaching In Place (In Situ)
Milling Method: Leach-Solvent-Extract-Precipitation
Year First Production: 1976
Discovery Year: 1966
Discovery Method: Ore-Mineral In Place
Years of Production:
Organization:
Significant: Y
Deposit Size: M

---

Physiography

Not available

---

Mineral Deposit Model

Model Name: Porphyry Cu, skarn-related

---

Orebody

Form: Pipe, Irregular

---

Structure

Type: L
Structure: Lakeshore Fault (Nnw, Dip 50-80W)-Post Ore Stock Fault Down to W

---

Alterations

Alteration Type: L
Alteration: Oxidation; Potassic, Phyllic, Argillic, Sericitization, & Propyllitic zones

---

Rocks

Name: Limestone
Role: Host
Description: Host for skarn mineralization
Age Type: Host Rock
Age Young: Tertiary

Name: Quartz Monzonite
Role: Associated
Age Type: Associated Rock Unit
Age Young: Late Cretaceous

Name: Andesite
Role: Associated
Age Type: Associated Rock
Age Young: Late Cretaceous

---

Analytical Data

Analytical Data: 0.76% Cu in Sulfide Ore, 1.03% Cu in Oxide Ore (1976)

---

Materials

Ore: Tremolite
Ore: Bornite
Ore: Bornite
Ore: Brochantite
Ore: Chalcocite
Ore: Chalcopyrite
Ore: Chrysocolla
Ore: Covellite
Ore: Cuprite
Ore: Diopside
Ore: Tenorite
Ore: Sphalerite
Ore: Pyrite
Ore: Molybdenite
Ore: Goethite
Ore: Garnet
Ore: Galena
Gangue: Quartz
Gangue: Magnetite
Gangue: Hematite
Gangue: Chlorite
Gangue: Calcite

---

Comments

Comment (Ownership): Mill Op Costs Are Increased By 30% After 15 Yrs Of Operation Instead Of Mill Capital Replacement. Cyprus Minerals Purchased Lakeshore From Noranda Inc. In June 1987 For Undisclosed Price Cyprus Minerals Merged With Amax Inc In November 1993

Comment (Production): Y-Lin Refers To Commodity Record Number. The Recovery Percentage For Product C Is A Combined Recovery For The Sulfide/Oxide Beneficiation Plant. Calculated Recovery Is 85.49%. Circuit Recoveries Are: Oxide-80% Sulfide-90%.

Comment (Workings): Water Is Pumped From Wells On Site And From Wells 7 Miles Away.

Comment (Reserve-Resource): Also Known As Lakeshore. Mine Is Operating As An Underground In-Situ Leach Operation Which Produced Only 45 Mt Copper In 1992.

Comment (Economic Factors): The Operation Was Shut Down In September, 1977 Due To Economic Problems & The Price Of Copper. Operation Reopened By Noranda In January 1980. Following Development Work And Other Delays, Full Production Of 5440 Mtpd Was Achieved In January 1981.

Comment (Deposit): Associated Rocks: quartz monzonite, quartz monzonite porphyry, skarn;n.d.;andesite, conglomerate, diabase, fanglomerate, limestone, quartzite, schist, volcaniclastics

Comment (Deposit): The Deposit Has 3 Principal Parts: 1) A Core Of Disseminated Sulfide Ore In Quartz Monzonite; 2) A Tactite Ore In Paleozoic And Prec Sediments At The Base And Marginal To The Thick Sulfide Deposit; And 3) An Enriched Blanket Of Oxide Ore Formed By Oxidation Of A Secondary Enriched Chalcocite Blanket Overlying The Core. A High-Angle Reverse Fault Offsets The Overlying Oxide Zone To The West From The Central Sulfide Zone On The East. Pyrite: Chalcopyrite Suggests A Pyrite Halo. USBM Gives Orebody Dimensions As: 6000 Ft Long, 1080 Ft Thick, 2500 Ft Wide, 500 Ft Deep.

Comment (Development): Previous Operator Hecla Mining Co And Noranda Lakeshore Mines, Inc. (1983); Ore Outcrop In Bottom Of Shallow Arroyo Was Discovered In Early 1880'S By Trout & Atchison. Based From Papago Indians 6 Patented And 19 Unpatented Lode Claims Encompasing 402 Acres; In Addition 10,142 Acres Leased From Papago Indians. Further Property Evaluation Was Undertaken In 1993.

Comment (Workings): Oxide Ore By Open Pit In Early Production, Sulfide And Tactite Ore By Room & Pillar, Block Caving. In 1884 Had 112 Ft Shaft & Drifting. In 1914 A New Vertical Shaft To 285 Ft. In 1993, An In-Situ Leach Operation.

---

References

Reference (Deposit): Builder Architect/Contractor Engineer, 11/76, P.14 (General)

Reference (Reserve-Resource): 'PCIA 1976-93; Cyprus-Amax Form 10K 1994-1996

Reference (Geology): 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.

Reference (Deposit): Petrick, Lakeshore, In Class Notes C.S.M.

Reference (Deposit): Mining Magazine 6/77 (General)

Reference (Reserve-Resource): Cyprus Minerals Co., Form 10-K Report. 12/31/92, P1.

Reference (Reserve-Resource): Cyprus Amax Minerals Company, Form 10-K, 12/31/95, P2.

Reference (Reserve-Resource): Noranda 1984 Ann. Rept. - Tactite Ore.

Reference (Reserve-Resource): Mining Record. Cyprus To Purchase Lakeshore Copper Facilities In Arizona; Wed., June 17, 1987, Denver, Co, P 1. (Grade Not Given)

Reference (Deposit): Mining Magazine, 5/75, P.335 (Processing, Byprod., Trans.)

Reference (Reserve-Resource): World Mining, 10/76, P. 56 (Reserves)

Reference (Deposit): Pay Dirt 8/25/75 (General)

Reference (Deposit): Skillings 11/20/76, P. 12 (General)

Reference (Deposit): Randol Mining Directory, 1996/97, U.S. Mines And Mining Companies, P144.

Reference (Deposit): Given, I.A., Ed., Mining Engineering Handbook, Vol. 1, Sme-Aime, 1973.

Reference (Deposit): Hecla Mining Co., Annual Reports 1970-1976

Reference (Deposit): Pay Dirt 4/28/69 (General)

Reference (Deposit): Mining Congress Journal 3/69 (General, Reserves)

Reference (Deposit): E/Mj 6/69 (General, Geology)

Reference (Deposit): Mining Congress Journal 11/69, P.26 (General, Reserves)

Reference (Deposit): Pay Dirt 9/29/69 (General)

Reference (Deposit): Pay Dirt 3/70 (History, Geology)

Reference (Deposit): Skillings 8/22/70 (General)

Reference (Deposit): Skillings 2/13/71 (General)

Reference (Deposit): E/Mj 8/73 (General)

Reference (Deposit): Skillings 6/15/74 (General)

Reference (Ownership): Pay Dirt (Ariz.) 3/78 (Superior Deal)

Reference (Reserve-Resource): Pay Dirt 6/23/69, P. 20 (Reserves)

Reference (Reserve-Resource): Pay Dirt 2/24/69 (Reserves)

Reference (Reserve-Resource): E/Mj 3/69, P. 172 (Reserves)

Reference (Production): Griffith,W.A., Et Al., Oct. 24, 1973, Development Of The Roast-Leach-Electrowin Process For Lakeshore, Heclamining Co. (Processing)

Reference (Other Database): Cimri

Reference (Production): E/Mj 6/75 (Beneficiation)

Reference (Deposit): Phillips, K.A., Beard, R.R., Niemuth, N.J., And Bain, D.R., 1991, Active Mines In Arizona--1992: Arizona Department Of Mines And Mineral Resources Directory 39, 20 P.

Reference (Deposit): Arizona Department Of Mines And Mineral Resources, 1994, Directory Of Active Mines In Arizona, Incorporating Sand and Gravel Operations -- 1994: Arizona Department Mines And Mineral Resources Directory 42, 24 P.

Reference (Deposit): South, 1972, M.S. Thesis, Univ Of Az.

Reference (Deposit): Harper and Reynolds, 1969, Mining Cong. Jour., V. 55, No. 11, P. 26-30

Reference (Deposit): Harper and Reynolds ,1969

Reference (Deposit): Romslo, 1950, USBM Ic 4706.

Reference (Deposit): Greeley, 1978, Admr Special Report No. 2, P. 83-87.

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): Singer and others, 2008

Reference (Deposit): Long, K.R., 1995, Production and reserves of Cordilleran (Alaska to Chile) porphyry copper deposits; in Pierce, F.W. and Bolm, J.G., eds., Porphyry Copper Deposits of the American Cordillera, Arizona Geological Society, Digest 20, p. 35-68.

Reference (Deposit): Johnston, W.P., 1972, K-Ar dates on intrusive rocks and alteration associated with the Lakeshore porphyry copper deposit, Pinal County, Arizona; Isochron/West: A Bulletin of Isotopic Geochronology, v. 4, p. 29-30.

---

Arizona Gold

"Where to Find Gold in Arizona" looks at the density of modern placer mining claims along with historical gold mining locations and mining district descriptions to determine areas of high gold discovery potential in Arizona. Read more: Where to Find Gold in Arizona.