Constriccion neogena en la Cordillera de la Costa, norte de Chile: neotectonica y datacion de superficies con 21Ne cosmogonicoNeogene constriction in the northern Chilean Coastal Cordillera: Neotectonics and surface dating using cosmogenic 21Ne
Neogene constriction in the northern Chilean Coastal Cordillera: Neotectonics and surface dating using cosmogenic 21Ne
| dc.contributor | en-US | |
| dc.contributor | es-ES | |
| dc.creator | Carrizo, Daniel | |
| dc.creator | Gonzalez, Gabriel | |
| dc.creator | Dunai, Tibor | |
| dc.date | 2010-06-21 | |
| dc.identifier | http://www.andeangeology.cl/index.php/revista1/article/view/V35n1-a01 | |
| dc.identifier | 10.5027/andgeoV35n1-a01 | |
| dc.description | Se documenta la actividad de fallas y el campo de deformacion neogena en la Cordillera de la Costa en las inmediaciones del Salar Grande, norte de Chile. La actividad de fallas se expresa en la forma de escarpes de falla y escarpes de limbo de pliegues. Sobre la base de la orientacion de escarpes se definen tres sistemas principales: WNW-ESE, N-S y NNW-SSE. Las fallas de orientacion NNW-SSE son del tipo dextral-inverso, en tanto que las fallas N-S y WNW-ESE son del tipo inverso. Mediante dataciones con 21Ne de origen cosmogenico se determina que las fallas dislocan un relieve de edad oligocena-miocena preservado en la Cordillera de la Costa. Valles inactivos, de edades que varian entre 4 y 2 Ma, incididos en este relieve, tambien se encuentran dislocados por las fallas. Dataciones 40Ar/39Ar de un nivel de ceniza desplazado por una falla de orientacion E-W y la deformacion de sedimentos asignados al Pleistoceno tardio sugieren que la actividad de fallas se ha mantenido durante el Cuaternario. El regimen de deformacion es de tipo constriccional, caracterizado por acortamiento subhorizontal en todas las direcciones, que se explica por el acomodo de la deformacion en la parte interna de un margen continental curvo sometido a convergencia oblicua.ABSTRACT:This work documents fault activity and the Neogene's strain field in northern Chilean Coastal Cordillera. Fault activity is expressed as a group of fault scarps and fault-bend fold scarps whose orientation defines three main domains WNW-ESE, N-S and NNW-SSE. The WNW-ESE and N-S faults show reverse kinematics, and NNW-SSE faults shows dextral-reverse kinematics. Exposure ages using cosmogemc 21Ne show that the faults disrupt an Oligocene-Miocene landscape preserved at the Coastal Cordillera. Inactive valleys incised in this landscape are offset by the faults showing that faults were active after 4 and 2 Ma. 40Ar/39Ar chronology of displaced volcanic tuffs and the deformation of Late Pleistocene sediments indicate that fault activity remain still active during the Quaternary. The deformation regime is constrictional and characterized by subhorizontal shortening in all directions, that is explained by oblique convergence along an active curved continental margin. | es-ES |
| dc.description | This work documents fault activity and the Neogene's strain field in northern Chilean Coastal Cordillera. Fault activity is expressed as a group of fault scarps and fault-bend fold scarps whose orientation defines three main domains WNW-ESE, N-S and NNW-SSE. The WNW-ESE and N-S faults show reverse kinematics, and NNW-SSE faults shows dextral-reverse kinematics. Exposure ages using cosmogemc 21Ne show that the faults disrupt an Oligocene-Miocene landscape preserved at the Coastal Cordillera. Inactive valleys incised in this landscape are offset by the faults showing that faults were active after 4 and 2 Ma. 40Ar/39Ar chronology of displaced volcanic tuffs and the deformation of Late Pleistocene sediments indicate that fault activity remain still active during the Quaternary. The deformation regime is constrictional and characterized by subhorizontal shortening in all directions, that is explained by oblique convergence along an active curved continental margin. | en-US |
| dc.format | application/pdf | |
| dc.format | text/html | |
| dc.language | eng | |
| dc.publisher | Servicio Nacional de Geología y Minería | en-US |
| dc.relation | http://www.andeangeology.cl/index.php/revista1/article/view/V35n1-a01/399 | |
| dc.relation | http://www.andeangeology.cl/index.php/revista1/article/view/V35n1-a01/html | |
| dc.source | Andean Geology; Vol 35, No 1 (2008) | es-ES |
| dc.source | Andean Geology; Vol 35, No 1 (2008) | en-US |
| dc.source | 0718-7106 | |
| dc.source | 0718-7092 | |
| dc.title | Constriccion neogena en la Cordillera de la Costa, norte de Chile: neotectonica y datacion de superficies con 21Ne cosmogonicoNeogene constriction in the northern Chilean Coastal Cordillera: Neotectonics and surface dating using cosmogenic 21Ne | es-ES |
| dc.title | Neogene constriction in the northern Chilean Coastal Cordillera: Neotectonics and surface dating using cosmogenic 21Ne | en-US |
| dc.type | info:eu-repo/semantics/article | |
| dc.type | info:eu-repo/semantics/publishedVersion | |
| dc.type | es-ES | |
| dc.type | en-US |
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Andean Geology
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