Subduction off the western margin of South America probably commenced during the Paleozoic and has continued to the present day between the Nazca Plate and the South America Plate, where the former subducts at a rate of below the latter. It has been accompanied by orogeny and volcanic activity, with three distinct phases of folding known as the Mochica, Peruvian and Inca phases which gave rise to faults and folds. The volcanic activity manifested itself as a set of volcanic arcs, such as the Tacaza arc with mineral-bearing calderas and the presently active Central Volcanic Zone which includes the Andagua volcanic field. In turn, the Central Volcanic Zone is one of three main volcanic arcs in the Andes which are separated by gaps without volcanic activity. Small volcanoes such as these of the Andagua volcanic field are a subordinate part of the Peruvian Central Volcanic Zone; most volcanoes are large and among these is Sabancaya with historical activity, El Misti with solfataric activity, Coropuna, which is the highest volcano in Peru and features Holocene activity, Firura and Solimana north and west from Coropuna, and Mismi, Hualca Hualca, Ampato, Chachani and Pichu Pichu. Additional volcanoes of this volcanic zone occur in Bolivia and Chile.