composition with porphyritic textures. Breccia zones with angular or locally rounded fragments are commonly associated with the intrusives. The sulfide mineralization typically occurs between or within fragments. These breccia zones are typically hydrothermal in nature, and may be manifested as pebble dikes. The deposits typically have an outer epidote – chlorite mineral alteration zone. A quartz – sericite alteration zone typically occurs closer to the center and may overprint. A central potassic zone of secondary biotite and orthoclase alteration is commonly associated with most of the ore. Fractures are often filled or coated by sulfides, or by quartz veins with sulfides. Closely spaced fractures of several orientations are usually associated with the highest grade ore. The upper portions of porphyry copper deposits may be subjected to supergene enrichment. This involves the metals in the upper portion being dissolved and carried down to below the water table, where they precipitate. Porphyry copper deposits are typically mined by open-pit methods. Notable examples Mexico Cananea La Caridad Santo Tomas Canada Highland Valley Chile Cerro Colorado Chuquicamata Collahuasi Escondida El Abra El Salvador El Teniente Los Pelambres Radomiro Tomić Peru Toquepala Cerro Verde, southeast of the city of Arequipa United States Ajo, Arizona Bagdad, Arizona Lavender Pit, Bisbee, Arizona Morenci, Arizona Pebble Mine, Alaska Safford Mine, Safford, Arizona San Manuel, Arizona Sierrita, Arizona Resolution Copper, Superior, Arizona El Chino, Santa Rita, New Mexico Ely, Nevada Bingham Canyon Mine, Utah Ray Mine, Arizona Indonesia Batu Hijau, Sumbawa Grasberg, West Papua at >3 billion tonnes at 1 ppm Au, is one of the world's largest and richest porphyry deposits of any type Tujuh Bukit, Java, still under exploration, but likely to be bigger than Batu Hijau Sungai Mak and Cabang Kiri, Gorontalo, at 292 million tonnes at 0.50 ppm gold and 0.47% copper Australia Cadia-Ridgeway Mine, New South Wales, copper-gold deposit mined by open pit and block caving. Northparkes copper porphyry deposit, New South Wales, with 63 million tonnes at 1.1% Cu and 0.5 ppm Au. Papua New Guinea Ok Tedi Panguna/Bougainville Copper Wafi-Golpu project/Wafi-Golpu mine Other Coclesito, Panama Majdanpek mine, Serbia Oyu Tolgoi is one of the world's largest and richest Cu porphyry deposits, Mongolia La Caridad, Sonora, Mexico Dizon, Philippines Saindak Copper Gold Project, Pakistan Porphyry-type ore deposits for metals other than copper Copper is not the only metal that occurs in porphyry deposits. There are also porphyry ore deposits mined primarily for molybdenum,