page_title: Incapillo
section_title: Geography and structure
hierarchical_section_title: Incapillo / Geography and structure
caption_attribution_description: English: Cerro Bonete Chico
context_page_description: Incapillo is a Pleistocene caldera, a depression formed by the collapse of a volcano, in the La Rioja province of Argentina. Part of the Argentine Andes, it is considered the southernmost volcanic centre in the Central Volcanic Zone of the Andes with Pleistocene activity. Incapillo is one of several ignimbritic or calderic systems that, along with 44 active stratovolcanoes, are part of the Central Volcanic Zone.
  Subduction of the Nazca Plate beneath the South America plate is responsible for most of the volcanism in the Central Volcanic Zone. After activity in the western Maricunga Belt volcanic arc ceased six million years ago, volcanism started up in the Incapillo region, forming the high volcanoes Monte Pissis, Cerro Bonete Chico and Sierra de Veladero. Later, a number of lava domes formed between these volcanoes.
  Incapillo is the source of the Incapillo ignimbrite, a medium-sized deposit comparable to the Katmai ignimbrite. With a volume of about 20.4 cubic kilometres, the Incapillo ignimbrite was erupted 0.52 ± 0.03 and 0.51 ± 0.04 million years ago. A caldera with dimensions of 5 by 6 kilometres was formed during the eruption.
context_section_description: Incapillo is located in Argentina's La Rioja province. The name "Incapillo" means "Crown of the Inca" in Quechua and is the highest caldera stemming from explosive activity in the world. It is also known as Bonete caldera.
  Incapillo is part of the Andean Central Volcanic Zone, which extends through the countries of Chile, Bolivia, and Argentina and includes six or more Quaternary caldera or ignimbrite systems, about 44 stratovolcanoes, and over 18 smaller centres. One of these stratovolcanoes, Ojos del Salado, is the world's highest volcano. This zone also includes the Altiplano-Puna volcanic complex and the Galan caldera farther south. Incapillo is the southernmost volcano of the Central Volcanic Zone with Pleistocene activity; the next such volcano to the south is Tupungato in the Southern Volcanic Zone at 33° southern latitude.
  Incapillo is a caldera with a diameter of 5 by 6 kilometres (3.1 mi × 3.7 mi) at an elevation of 5,750 metres (18,860 ft). The three adjacent volcanic centres of Monte Pissis (6,882 metres (22,579 ft)), Cerro Bonete Grande (6,436 metres (21,115 ft)), and Cerro Bonete Chico (6,759 metres (22,175 ft)) are also considered part of this volcanic complex and are among the highest on Earth. These centres surround the ignimbrite and lava domes. The walls of the caldera are 250 metres (820 ft) high. A uniform ignimbrite, called the Incapillo ignimbrite, is rich in pumice and forms the bulk of the caldera walls.
  Around the caldera lie 40 lava domes, which extend northwest-southeast. There is an eastern group between Monte Pissis and Cerro Bonete Chico and a western one on the Sierra de Veladero. Overall, the domes have heights of 100–600 metres (330–1,970 ft) and a basal apron of about 1 kilometre (0.62 mi) width of erosional material. Some domes have water-filled craters with widths of 20 metres (66 ft) at their top. Domes on the caldera's northern side are dacitic and show signs of alteration. Some domes are probably part of the pre-caldera complex, and several rhyodacitic domes were modified by erosional processes after caldera formation; these were formerly considered erosional remnants. Older domes have reddish oxidized colours in satellite images. The total volume of the domes is about 16 cubic kilometres (3.8 cu mi).
  Next to a heavily hydrothermally altered lava dome in the centre of the caldera lies the Laguna Corona del Inca. This 350 metres (1,150 ft) deep and 5,300 metres (17,400 ft) high lake measures 2 by 1 kilometre (1.24 mi × 0.62 mi). The lake has probably generated the evaporite and lacustrine deposits that lie on the caldera floor. Water temperatures of 13 °C (55 °F) obtained by satellite measurements suggest that some hydrothermal activity persists. The lake is fed by meltwater.
caption: Cerro Bonete Chico
exif: {"Image Make": "Canon", "Image Model": "Canon PowerShot A520", "Image Orientation": "Horizontal (normal)", "Image XResolution": "72", "Image YResolution": "72", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "QuickTime 7.1.6", "Image DateTime": "2007:06:05 14:34:14", "Image HostComputer": "Mac OS X 10.4.9", "Image ExifOffset": "229", "EXIF ExposureTime": "1/1000", "EXIF FNumber": "5", "EXIF ExifVersion": "0220", "EXIF DateTimeOriginal": "2006:12:03 16:45:37", "EXIF DateTimeDigitized": "2006:12:03 16:45:37", "EXIF ShutterSpeedValue": "319/32", "EXIF ApertureValue": "149/32", "EXIF ExposureBiasValue": "0", "EXIF MaxApertureValue": "139/32", "EXIF MeteringMode": "Pattern", "EXIF Flash": "Flash did not fire, auto mode", "EXIF FocalLength": "16", "EXIF ColorSpace": "sRGB", "EXIF ExifImageWidth": "640", "EXIF ExifImageLength": "453", "EXIF SensingMethod": "One-chip color area"}