Nevado de Longaví is a volcano in the Andes of central Chile. The high volcano lies in the Linares Province, which is part of the Maule Region. It features a summit crater and several parasitic vents. The volcano is constructed principally from lava flows. Two collapses of the edifice have carved collapse scars into the volcano, one on the eastern slope known as Lomas Limpias and another on the southwestern slope known as Los Bueye. The volcano features a glacier and the Achibueno and Blanco rivers originate on the mountain. The oldest volcanic activity occurred one million years ago. After a first phase characterized by the production of basaltic andesite, the bulk of the edifice was constructed by andesitic lava flows. The volcanic rock that makes up Nevado de Longaví features an unusual magma chemistry that resembles adakite (having geochemical characteristics of magma thought to have formed by partial melting of altered basalt that is subducted below volcanic arcs). It may be the consequence of the magma being unusually water-rich, which may occur because the Mocha fracture zone subducts beneath the volcano. Nevado de Longaví was active during the Holocene. 6,835 ± 65 or 7,500 years before present an explosive eruption deposited pumice more than away from the volcano. A lava flow was then erupted over the pumice. The last eruption occurred about 5,700 years ago and formed a lava dome. The volcano has no historic eruptions but fumarolic activity is ongoing. Nevado de Longaví is monitored by the National Geology and Mining Service of Chile. Geography Nevado de Longaví lies in the Longaví commune of Linares Province, Maule Region. Regional Nevado de Longaví lies in the Andean Mountain Range's Southern Volcanic Zone, which extends between 33 and 46 degrees southern latitude. It is one among 60 volcanoes in Chile and Argentina that lie within the Southern Volcanic Zone. Among the largest volcanic eruptions in this area were the 1932 Quizapu and the 1991 Cerro Hudson eruptions. Nevado de Longaví is usually put into the "Transitional Southern Volcanic Zone", one of the four segments which the Southern Volcanic Zone is subdivided into; they are characterized by different thicknesses of the crust that the volcanoes are constructed on and by differences in the volcanic rocks. Farther east lie the Tatara-San Pedro and Laguna del Maule volcanoes. Geology Volcanism in the Southern Volcanic Zone is caused by the subduction of the Nazca