How long is the Central Volcanic Zone of the Andes?
10858103#7
The South Volcanic Zone (SVZ) extends roughly from Central Chile's Andes at the latitude of Santiago, at ca. 33°S, to Cerro Arenales in Aysén Region at ca. 46°S, a distance of well over 870 mi (1,400 km). The arc has formed due to subduction of the Nazca Plate under the South American Plate along the Peru–Chile Trench. The northern boundary of the SVZ is marked by the flat-slab subduction of the Juan Fernández Ridge, which is believed to have produced a volcanic gap called the "Pampean flat-slab segment" in the Norte Chico region since the late Miocene. The southern end of the SVZ is marked by the Chile Triple Junction where the Chile Rise subducts under South America at the Taitao Peninsula giving origin to the "Patagonian Volcanic Gap". Further south lies the Austral Volcanic Zone.
Andean Volcanic Belt
13069204#3
Volcanism in the Central Andes is the consequence of the subduction of the Nazca Plate beneath the South American Plate and occurs in form of the long Central Volcanic Zone, one of four volcanic belts in the Andes. The Peruvian and the Pampean "flat slab" segments separate this volcanic belt from its neighbours, the Northern Volcanic Zone to the north and the Southern Volcanic Zone south respectively.
Putana (volcano)
56228982#3
Wheelwright is part of the Central Volcanic Zone, which together with the Northern Volcanic Zone, the Southern Volcanic Zone and the Austral Volcanic Zone is one among four separate volcanic zones in the Andes; these volcanic zones are separated by gaps without recent volcanic activity. Since 23 million years ago the Central Volcanic Zone has given rise to compound volcanoes, calderas and stratovolcanoes, which are formed mainly by andesitic or dacitic rocks. Ojos del Salado, a member of the Central Volcanic Zone, is the second tallest mountain in the Andes and the highest active volcano in the world. Further, the Maricunga volcanic belt in the same region is site of major precious metal deposits.
Wheelwright caldera
56351803#9
Off the western coast of South America, the Nazca Plate subducts beneath the South America Plate at a rate of about ; this subduction is responsible for volcanic activity in the Central Volcanic Zone and elsewhere in the Andes. Volcanism does not occur along the entire length of the subduction zone; north of 15° and south of 28° the subducting plate moves downward at a shallower angle and this is associated with the absence of volcanic activity. Other volcanic zones exist in the Andes, including the Northern Volcanic Zone in Colombia and Ecuador and the Southern Volcanic Zone also in Chile. A furtherourth volcanic zone, the Austral Volcanic Zone, is caused by the subduction of the Antarctic Plate beneath the South America Plate and lies south of the Southern Volcanic Zone.
Antofalla
26119539#4
La Pacana is part of the Central Volcanic Zone, one of the four volcanic zones that make up the Andean Volcanic Belt and which are separated from each other by gaps without ongoing volcanic activity. A number of stratovolcanoes and ignimbrite-forming centres have erupted in the Central Volcanic Zone since the Miocene, about 50 of which are considered to be active. In addition, the Central Volcanic Zone features about 18 minor volcanic fields. The largest historical eruption of the Andes occurred in 1600 at Huaynaputina in Peru in the Central Volcanic Zone, and the most active volcano of the Central Volcanic Zone is Láscar in Chile.
La Pacana
8973251#8
The Andes are a site of volcanic activity, which is usually subdivided into four separate volcanic zones: the Northern Volcanic Zone, the Central Volcanic Zone, the Southern Volcanic Zone and the Austral Volcanic Zone. These volcanic zones are separated by gaps where no recent volcanic activity has occurred. These gaps are not static; the gap separating the Austral and the Southern Volcanic Zones has been moving northward for the past 15-20 million years. The Southern Volcanic Zone itself is subdivided into additional volcanic zones, the Northern, Transitional, Central and Southern Southern Volcanic Zone and contains over two calderas and over 60 volcanoes with Quaternary activity.
Mentolat
1368258#1
Volcanic activity in the Andes occurs in four regions, the Northern Volcanic Zone, the Central Volcanic Zone, the Southern Volcanic Zone and the Austral Volcanic Zone. The first three of these are found where the Nazca Plate subducts beneath the South America Plate, while the last zone occurs at the subduction zone of the Antarctic Plate. The Andean Central Volcanic Zone runs along the Western Cordillera of the Andes and along the Altiplano. During the Neogene, the position of this volcanic arc moved eastward and the arc became broader, probably due to a change in the tilt of the slab of the Nazca Plate. Volcanic activity during this time was heavily influenced by local strike-slip faults which acted to channel the magma flows. About 7 million years ago, tectonics and volcanic activity changed in the region probably in response to the delamination of the crust beneath the region: Large scale ignimbrites were erupted at Galán and small back-arc volcanoes erupted mafic basaltic andesite lavas. These small volcanic centres consist of lava domes, lava flows, maars, scoria cones and tuff rings.
Antofagasta de la Sierra
10858103#14
The different volcanic zones are intercalated by volcanic gaps, zones that, despite lying at the right distance from an oceanic trench, lack volcanic activity. The Andes has three major volcanic gaps the "Peruvian flat-slab segment" (3 °S–15 °S), the "Pampean flat-slab segment" (27 °S–33 °S) and the "Patagonian Volcanic Gap" (46 °S–49 °S). The first one separates the Northern from the Central Volcanic Zone, the second the Central from the Southern and the last separates the Southern from the Austral Volcanic Zone. The Peruvian and Pampean gaps coincide with areas of flat slab (low angle) subduction and therefore the lack of volcanism is believed to be caused by the shallow dip of the subducting Nazca Plate in these places. The shallow dip has in turn been explained by the subduction of the Nazca Ridge and the Juan Fernández Ridge for the Peruvian and Pampean gaps respectively. Since the Nazca and Juan Fernández Ridge are created by volcanic activity in Pacific hotspots (Easter and Juan Fernández) it can be said that volcanic activity in the Pacific is responsible for the suppression of volcanism in parts of the Andes.
Andean Volcanic Belt
12882604#4
Volcanism along the Andes occurs in four separate belts, the Northern Volcanic Zone, the Central Volcanic Zone, the Southern Volcanic Zone and the Austral Volcanic Zone. Tocorpuri is part of the Central Volcanic Zone, which in this region is characterized by an ignimbrite formation and individual volcanoes, with compositions ranging from andesite over dacite to rhyolite. Both these formations are emplaced on a Cretaceous-Miocene basement formed by sediments and volcanic rocks, which overlay Precambrian-Paleozoic layers. Aside from stratovolcanoes which are lined up in the Western Cordillera, the Altiplano-Puna volcanic complex is also a component of the Central Volcanic Zone and is formed by large calderas and lava domes such as La Torta.
Tocorpuri
4928090#5
Volcanoes in the Andes occur in four separate regions: the Northern Volcanic Zone between 2°N and 5°S, the Central Volcanic Zone between 16°S and 28°S, the Southern Volcanic Zone between 33°S and 46°S, and the Austral Volcanic Zone, south of the Southern Volcanic Zone. These volcanic zones are separated by areas where recent volcanism is absent; one common theory is that the subduction processes responsible for volcanism form a subducting plate that is too shallow to trigger the formation of magma. This shallow subduction appears to be triggered by the Nazca Ridge and the Juan Fernandez Ridge; the areas where they subduct beneath the Peru-Chile Trench coincide with the limits of the Central Volcanic Zone. It is possible that when these ridges are subducted, the buoyancy they carry disrupts the subduction process and reduces the supply of water, which is important for the formation of melts.
Lascar (volcano)
52266263#0
The Central Chilean Andes have an arid climate since the Miocene. Thus, a number of volcanic centres going back as far as 25 million years are well preserved. Geologically, this area belongs to the Central Volcanic Zone, a volcanic belt in the Andes, whose magmas are heavily influenced by the thick crust of the area.
Leon Muerto
10858103#5
The Central Volcanic Zone (CVZ) is a volcanic arc in western South America. It is one of the four volcanic zones of the Andes. The Central Volcanic Zone extends from Peru to Chile and forms the western boundary of the Altiplano plateau. The volcanic arc has formed due to subduction of the Nazca Plate under western South America along the Peru–Chile Trench. To the south the CVZ is limited by the "Pampean flat-slab segment" or "Norte Chico flat-slab segment", a region devoid of volcanism due to a lower subduction angle caused by the subduction of Juan Fernández Ridge.
Andean Volcanic Belt