Taapaca is a Holocene volcanic complex in northern Chile's Arica y Parinacota Region. Located in the Chilean Andes, it is part of the Central Volcanic Zone of the Andean Volcanic Belt, one of four distinct volcanic chains in South America. The town of Putre lies at the southwestern foot of the volcano. Like other volcanoes of the Central Volcanic Zone, Taapaca formed from the subduction of the Nazca Plate beneath the South America Plate. It lies on the western margin of the Altiplano high plateau, on top of older volcanic and sedimentary units. Taapaca has mainly erupted dacite, in the form of numerous lava domes, although an andesitic stratovolcano is also present. Volcanic activity at Taapaca occurred in several stages starting during the Plio-Pleistocene. The emplacement of lava domes was often followed by their collapse and the formation of block-and-ash avalanches, and parts of the volcano underwent sector collapses (large landslides). It was at first assumed that activity ended during the Pleistocene, but late eruptions occurred until 2,300 years ago; the latest is dated to 320 BCE. The Chilean Geological Service monitors the volcano as it is a hazard to Putre, but eruptions could also impact local roads and areas as far east as Bolivia.
Name The term tara paka is Aymara for "two-headed eagle" or "winter (prey) bird", and Quechua for Andean eagle. It is also known as Nevados de Putre; sometimes "Nevados de Putre" is used to refer to the volcanic complex and "Taapaca" to its highest summit. The term taapaca may also be the origin of the term tarapaca and could be an Aymara name for the founder deity Viracocha. Putre in turn appears to mean "sound of falling water" in Aymara.
Geography and geology Taapaca lies in the Parinacota province of the Arica y Parinacota Region. Northern Chile has little documented volcanic activity during the last ten thousand years with the majority of eruptions documented at Guallatiri, Lascar and Parinacota. The first and the last of these three volcanoes as well as Taapaca itself are part of the Lauca National Park. Taapaca volcano can be reached from the Tambo Quemado-Arica international road.
Regional setting Volcanism in the Andes is caused by the subduction of the Nazca Plate and the Antarctic Plate beneath the South America Plate in the Peru-Chile Trench, at rates of 7–9 centimetres per year (2.8–3.5 in/year) and 2 centimetres per year (0.8 in/year), respectively. The process generates fluids that are ultimately responsible for the evolution of subduction-associated magmas when they interact with the mantle wedge above the downgoing plate. This subduction does not result in volcanic activity everywhere; in places where the process is shallower ("flat slab" subduction) there is no recent volcanism. Volcanism has been ongoing in the Andes since about 185 million years ago, with an increase about 27 million years ago when the Farallon Plate broke up. In 1994, the Andes were considered to contain about 178 volcanoes with Holocene activity, of which 60 were further assumed to have been active during historical time.
Local setting Taapaca is part of the Central Volcanic Zone of the Andes, which along with the Northern Volcanic Zone, the Southern Volcanic Zone and the Austral Volcanic Zone is one of the four volcanic belts of the Andes; these volcanic belts are separated by areas where no recent volcanism has occurred. The Central Volcanic Zone has about 44 active volcanoes and several other caldera/ignimbrite and volcanic field centres. Older volcanoes are often well preserved owing to the dry climate. This volcanic zone features the highest volcanoes in the world, which reach elevations of 5,000–7,000 metres (16,000–23,000 ft) here. The largest historical eruption in the Central Volcanic Zone occurred at Huaynaputina in 1600 and Lascar is the most active volcano in the region; otherwise volcanic activity is poorly recorded as most edifices are remote from human habitation. Taapaca is located on the western margin of the Altiplano, where the Western Cordillera has developed since the Oligocene. The basement beneath the volcano is formed by several principally volcanic formations, including the Lupica and sedimentary Huaylas formations and the Lauca ignimbrite (2.72 million years old); this basement is of Oligocene to Pliocene age. In some places, a Proterozoic basement formed by amphibolites, gneisses and serpentinites crops out. The volcanoes of Condoriri, Pomerape, Larancagua and Parinacota lie to the east of Taapaca. The area of the volcano is subject to contractional tectonics, with a major thrust fault passing close by, but their relationship to Taapaca's volcanism is not clear.
Volcano
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