BackgroundIn this region of the Andes, the volcanoes are about 90 km above the top of the subducting slab of the Nazca place, the so-called Benioff zone, which dips at an angle of 25 degrees. The subducting plate is broken into different segments subducting at different angles under continental crust of varying thickness. This results in zones of different magma generation. Volcanoes around 33-34 deg S are predominantly andesitic, while volcanoes south of 37 deg S are more basaltic. The Laguna del Maule volcano lies in this transition zone. It has more silica-rich, even rhyolite lavas than the volcanoes further to the south, which are mainly basaltic.
4 volcanic units are distinguished in the evoution of the Laguna del Maule volcanic complex:
1) Valley unit
2) Dikes and Volcanic neck unit
3) Volcanic Cones
4) Lake unit
Valley unit: 14 lava flows are found exposed in the upper part of the Maule river valley. Their vents are covered by younger lava flows of the Lake unit.
The Lake unit consists of rhyolitic domes and flows, as well a cluster of Pleistocene cones found around Maule Lake. The individual vents include Domo del Maule, Loma de los Espejos, Colada Occidental, Colada Dendrifonne, Colada las Nieblas, Cerro Barrancas, Colada Cari-Launa, and an explosion crater on the eastern side of the lake. The latter represents the latest activity from Laguna del Maule.
- Frederick A. Frey, David C. Gerlach, Rosemary L. Hickey, Leopoldo Lopez-Escobar and Francisco Munizaga-Villavicencio (1984) "Petrogenesis of the Laguna del Maule volcanic complex, Chile (36° S)", Contributions to Mineralogy and Petrology, Volume 88, Numbers 1-2, 133-149
See also: Sentinel hub | Landsat 8