Pali Aike Volcanic Field (Argentina)

The Pali-Aike volcanic field is a volcanic field along the Argentina–Chile border. It is part of a family of back-arc volcanoes in Patagonia, which formed from processes involving the collision of the Chile Ridge with the Peru–Chile Trench. It lies farther east than the Austral Volcanic Zone, the volcanic arc that makes up the Andean Volcanic Belt at this latitude. Pali-Aike formed over sedimentary rock of Magallanes Basin, a Jurassic-age basin starting from the late Miocene as a consequence of regional tectonic events. The volcanic field consists of an older plateau basalt formation and younger volcanic centres in the form of pyroclastic cones, scoria cones, maars and associated lava flows. There are approximately 467 vents in an area of 4,500 square kilometres (1,700 square miles). The vents often form local alignments along lineaments or faults, and there are a number of maars and other lakes, both volcanic and non-volcanic. The volcanic field is noteworthy for the presence of large amounts of xenoliths in its rocks and because the maar Potrok Aike is located here, where palaeoclimate data have been obtained. The field was active starting from 3.78 million years ago. The latest eruptions occurred during the Holocene, as indicated by the burial of archaeological artifacts; the Laguna Azul maar formed about 3,400 years before present. Humans have lived in the region for thousands of years, and a number of archaeological sites such as the Fell Cave are located in the field. Presently, parts of the volcanic field are protected areas in Chile and Argentina, and the city of Rio Gallegos in Argentina is within 23 kilometres (14 mi) of the volcanic field.