Search results
Results From The WOW.Com Content Network
Porphyry copper deposits represent an important resource and the dominant source of copper that is mined today to satisfy global demand. [6] Via compilation of geological data, it has been found that the majority of porphyry deposits are Phanerozoic in age and were emplaced at depths of approximately 1 to 6 kilometres with vertical thicknesses on average of 2 kilometres. [6]
Arizona is known as the Copper State because it produces two-thirds of US copper annually. Laramide copper porphyry deposits are common around Tucson and include the Twin Buttes, Sierrita-Esperanza, Rosemont, Silver Bell and Mission-Pima mines, as well as the historical Ajo mine to the west.
Phyllic alteration typically forms in the base-metal zone of a porphyry system. [2] Alteration assemblages vary with depth and with degree of fluid interaction. In deep environments, the most highly altered areas are veins and thin selvages, or halos, that surround them. The selvages are generally <10 cm in diameter and composed of major ...
This is common in porphyry copper and porphyry molybdenum deposits. Argillic alteration, commonly present in the distal areas of porphyry deposits, is a low-temperature assemblage that converts feldspars and some other minerals into clay minerals such as kaolinite and illite. It can overprint older, higher-temperature alteration assemblages. [13]
Gila County, Arizona: Freeport-McMoRan: Copper ore, leached 5 (2021) [2] 18 Carlota Gila County, Arizona: KGHM Polska Miedź: Porphyry copper open pit, producing copper cathode 3.2 (2018) [10] 19 Pumpkin Hollow (see Anaconda) Lyon County, Nevada: Nevada Copper IOCG skarn, underground, producing copper concentrate - (2019) [11]
Resolution Copper (RCM) is a joint venture owned by Rio Tinto and BHP formed to develop and operate an underground copper mine near Superior, Arizona, U.S. The project targets a deep-seated porphyry copper deposit located under the now inactive Magma Mine .
The San Manuel Copper Mine was a surface and underground porphyry copper mine located in San Manuel, Pinal County, Arizona. Frank Schultz was the original discoverer, in 1879, but the main body of the deposits were discovered by Henry W. Nichols in 1942. The exploration drilling went on from 1943 to 1948, with the first mine shaft built 1948.
Iron oxide copper gold (IOCG) deposits are considered to be metasomatic expressions of large crustal-scale alteration events driven by intrusive activity. The deposit type was first recognised by discovery and study of the supergiant Olympic Dam copper-gold-uranium deposit (Olympic Dam mine), and South American examples.