Tyrone-Chino-Hillsboro porphyry copper deposits

Region West, Southwest
Mineral systems
Deposit types
Critical minerals
Other minerals

Information leading to the delineation of this focus area

Basis for focus area District boundaries from McLemore (2017).
Identified resources Historical production of copper, gold, manganese, PGE, and silver.
Production In about 3 months of production in 1982, the Copper Flats mine produced 1.48 Mst of ore recovering 7.4 Mlbs Cu, 2,301 oz Au, and 55,966 oz Ag (Zimmerman and others, 2020). Copper production at the Tyrone mine in 2014 was about 94 Mlbs. In 2019, the Chino open pit mine produced 175 Mlbs Cu. Small amount of byproduct PGE production from smelter returns. Minor Mn production from the Hillsboro district.
Status Past and current mining at Chino; Hillsboro/Copper Flat recently released a NI 43-101 (Zimmerman and others, 2020) and is in permitting.
Estimated resources The Copper Flat mine has a future planned mine life of 11.1 years with estimated-life-of mine recoveries of 628,015,000 lbs Cu, 15,717,000 lbs Mo, 227,000 oz Au, and 5,950,000 oz Ag (Zimmerman and others, 2020). The Chino mine (Santa Rita) is estimated to hold 324 million tonnes (Mt) of Proven and Probable ore reserves tonnes grading 0.45% Cu and containing approximately 2.7 billion lbs Cu.
Geologic maps Richter and Lawrence (1983), scale 1:250,000; Richter and others (1986), scale 1:24,000.
Geophysical data Inadequate aeromagnetic and aeroradiometric coverage.
Favorable rocks and structures Cretaceous andesite flows, breccias, and volcaniclastic rock. Andesite is bounded by Paleozoic sedimentary rocks (McLemore and others, 1999).
Deposits Chino (Santa Rita) mine (MRDS dep_id: 10087992; USMIN Site_ID: NM00013), Tyrone (MRDS dep_id: 10174772), Copper Flat mine (MRDS dep_id: 10150841), Pine Group (MRDS dep_id: 10012001), Black Sheep Group (MRDS dep_id: 10011995), Black Magic Claim (MRDS dep_id: 10011994), Viola Claim (MRDS dep_id: 10012004), Wagon Wheel and Prospect Group (MRDS dep_id: 10012005), Black Colt mine (1880s) (MRDS dep_id: 10107958), Palma Group (MRDS dep_id: 10097806), Lost Treasure and Gold Quartz Group (MRDS dep_id: 10014774), Old Claim (MRDS dep_id: 10014775), Manhattan and Pleasant View mines (MRDS dep_id: 10014789).
Evidence from mineral occurrences MRDS; USMIN.
Geochemical evidence Cobalt ranges from 0.05 to 69.4 mg/L in process and leachate waters (Phillip and Myers, 2003). Manganese veins in Silver City 1 x 2 degree quadrangle mineral resource assessment broadly associated with anomalous Pb, Zn, Ba, and Mn abundances in magnetite fraction of panned streambed sediments (Richter and others, 1983).
Geophysical evidence Unknown.
Evidence from other sources Freeport McMoRan owns Chino and Tyrone and has chemical data on all process waters and waste material. The volumes of water and material make secondary recovery of critical and other elements attractive. The company has obtained patents on the recovery of Re and working on patents for the recovery of other critical elements.
Comments See Bryce and others (2014) for pilot plant technologies; Co, Al and likely REE, PGE are known in these waters and should be considered a potential resource.
Cover thickness and description Additional porphyry deposits are likely in this belt.
Authors Virginia T. McLemore, Joshua M. Rosera.
New data needs Detailed mineralogy containing Co, REE, Al on ore and waste samples; geochemistry of process and waste waters.
Geologic mapping and modeling needs Detailed geology-structure-alteration-mineralization mapping.
Geophysical survey and modeling needs High resolution, Rank 1 aeromagnetic and aeroradiometric coverage.
Digital elevation data needs Lidar complete.