The Maipo Orocline: A first scale structural feature in the Miocene to Recent geodynamic evolution in the central Chilean Andes
In this paper we show the results of a paleomagnetic study carried out along the western Andes of central Chile from 30° to 36°S. Whereas paleomagnetic analysis from Jurassic to Late Cretaceous rocks in the Pampean flat slab segment shows small or non significant clockwise vertical-axis rotations, r...
| Autores: | , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2013 |
| País: | Chile |
| Institución: | CONICYT Chile |
| Repositorio: | SciELO Chile |
| OAI Identifier: | oai:scielo:S0718-71062013000300002 |
| Acceso en línea: | http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-71062013000300002 |
| Access Level: | acceso abierto |
| Palabra clave: | Central Andes Maipo Orocline Bolivian Orocline Juan Fernández Ridge Paleomagnetism |
| Sumario: | In this paper we show the results of a paleomagnetic study carried out along the western Andes of central Chile from 30° to 36°S. Whereas paleomagnetic analysis from Jurassic to Late Cretaceous rocks in the Pampean flat slab segment shows small or non significant clockwise vertical-axis rotations, results obtained in Late Jurassic to Neogeone rocks to the south, on the normal subduction segment, show sistematically clockwise rotations up to 40°. Paleomagnetic rotations are coeval with thrusting along the High Andes in Late Miocene times. We propose a coupled Bolivian Orocline-Juan Fernández Ridge (JFR) model where a far-field component of clockwise rotation related to the formation of the Bolivian Orocline was first acquired by the margin between 31° and 33°S. The same area was later rotated by a slight counterclockwise component related to the subduction of the JFR over the last 10 Ma. South of 33°S the clockwise rotations related to the Bolivian Orocline component were amplified by the subduction of the JFR. |
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