Pliocene extensional tectonics in the Eastern Central Patagonian Cordillera: Geochronological constraints and new field evidence
Recent field work and review of radiometric data obtained from Neogene lavas and plutonic rocks exposed in the Eastern Central Patagonian Cordillera (46-48°S), which overlie subducted segments of the South Chile Ridge, suggest important Late Miocene to Pleistocene morphological changes in relation t...
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todo:paper_09544879_v19_n6_p413_Lagabrielle2023-10-03T15:51:44Z Pliocene extensional tectonics in the Eastern Central Patagonian Cordillera: Geochronological constraints and new field evidence Lagabrielle, Y. Suárez, M. Malavieille, J. Morata, D. Espinoza, F. Maury, R.C. Scalabrino, B. Barbero, L. de la Cruz, R. Rossello, E. Bellon, H. extensional tectonics faulting geochronology Pliocene radiometric method subduction uplift Patagonia South America Recent field work and review of radiometric data obtained from Neogene lavas and plutonic rocks exposed in the Eastern Central Patagonian Cordillera (46-48°S), which overlie subducted segments of the South Chile Ridge, suggest important Late Miocene to Pleistocene morphological changes in relation to base level variations and/or tectonic events. We present new field observations from a region south of Lago General Carrera-Buenos Aires, between the main Cordillera and the Meseta del Lago Buenos Aires, demonstrating that normal faulting controlled valley incisions and occurred during lava emplacement at 5-4 Ma and after 3 Ma. We also show that the 12 Ma basaltic flows of the Meseta del Lago Buenos Aires (∼2000 m a.s.l.) have been subjected to deep incision, with younger lavas dated at 1.2 Ma partially filling the valleys. These incisions are thought to reflect progressive eastward tilting of the entire meseta. Our new observations, together with additional features from Central Patagonia, strongly suggest that tectonic events led to a regional widespread morphological change after 5 Ma. The coincidence in time and space between the subduction of segments of the South Chile Ridge at 6 and 3 Ma causing opening of a slab window, and strong base level variations in the studied area, suggests a cause-and-effect relationship. In Central Patagonia, compressional tectonics ended well before extensional events reported here. Causes of uplift and further extension are probably completely disconnected. The uplift is purely tectonic in origin and occurred prior to the subduction of the South Chile Ridge. Extension should be a consequence of this subduction. © 2007 Blackwell Publishing Ltd. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_09544879_v19_n6_p413_Lagabrielle |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
extensional tectonics faulting geochronology Pliocene radiometric method subduction uplift Patagonia South America |
| spellingShingle |
extensional tectonics faulting geochronology Pliocene radiometric method subduction uplift Patagonia South America Lagabrielle, Y. Suárez, M. Malavieille, J. Morata, D. Espinoza, F. Maury, R.C. Scalabrino, B. Barbero, L. de la Cruz, R. Rossello, E. Bellon, H. Pliocene extensional tectonics in the Eastern Central Patagonian Cordillera: Geochronological constraints and new field evidence |
| topic_facet |
extensional tectonics faulting geochronology Pliocene radiometric method subduction uplift Patagonia South America |
| description |
Recent field work and review of radiometric data obtained from Neogene lavas and plutonic rocks exposed in the Eastern Central Patagonian Cordillera (46-48°S), which overlie subducted segments of the South Chile Ridge, suggest important Late Miocene to Pleistocene morphological changes in relation to base level variations and/or tectonic events. We present new field observations from a region south of Lago General Carrera-Buenos Aires, between the main Cordillera and the Meseta del Lago Buenos Aires, demonstrating that normal faulting controlled valley incisions and occurred during lava emplacement at 5-4 Ma and after 3 Ma. We also show that the 12 Ma basaltic flows of the Meseta del Lago Buenos Aires (∼2000 m a.s.l.) have been subjected to deep incision, with younger lavas dated at 1.2 Ma partially filling the valleys. These incisions are thought to reflect progressive eastward tilting of the entire meseta. Our new observations, together with additional features from Central Patagonia, strongly suggest that tectonic events led to a regional widespread morphological change after 5 Ma. The coincidence in time and space between the subduction of segments of the South Chile Ridge at 6 and 3 Ma causing opening of a slab window, and strong base level variations in the studied area, suggests a cause-and-effect relationship. In Central Patagonia, compressional tectonics ended well before extensional events reported here. Causes of uplift and further extension are probably completely disconnected. The uplift is purely tectonic in origin and occurred prior to the subduction of the South Chile Ridge. Extension should be a consequence of this subduction. © 2007 Blackwell Publishing Ltd. |
| format |
JOUR |
| author |
Lagabrielle, Y. Suárez, M. Malavieille, J. Morata, D. Espinoza, F. Maury, R.C. Scalabrino, B. Barbero, L. de la Cruz, R. Rossello, E. Bellon, H. |
| author_facet |
Lagabrielle, Y. Suárez, M. Malavieille, J. Morata, D. Espinoza, F. Maury, R.C. Scalabrino, B. Barbero, L. de la Cruz, R. Rossello, E. Bellon, H. |
| author_sort |
Lagabrielle, Y. |
| title |
Pliocene extensional tectonics in the Eastern Central Patagonian Cordillera: Geochronological constraints and new field evidence |
| title_short |
Pliocene extensional tectonics in the Eastern Central Patagonian Cordillera: Geochronological constraints and new field evidence |
| title_full |
Pliocene extensional tectonics in the Eastern Central Patagonian Cordillera: Geochronological constraints and new field evidence |
| title_fullStr |
Pliocene extensional tectonics in the Eastern Central Patagonian Cordillera: Geochronological constraints and new field evidence |
| title_full_unstemmed |
Pliocene extensional tectonics in the Eastern Central Patagonian Cordillera: Geochronological constraints and new field evidence |
| title_sort |
pliocene extensional tectonics in the eastern central patagonian cordillera: geochronological constraints and new field evidence |
| url |
http://hdl.handle.net/20.500.12110/paper_09544879_v19_n6_p413_Lagabrielle |
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