Middle to late Miocene extensional collapse of the North Patagonian Andes (41°30′-42°S)
The hinterland zone of the North Patagonian Andes between 41° and 43°S constitutes a poorly explored sector of the Andes, where no structural studies and scarce geochronological determinations have been carried out. This paper focuses on two isolated volcanic sections hosted at the main Andes, in wh...
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2015
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00401951_v657_n_p155_Tobal http://hdl.handle.net/20.500.12110/paper_00401951_v657_n_p155_Tobal |
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paper:paper_00401951_v657_n_p155_Tobal2023-06-08T15:04:01Z Middle to late Miocene extensional collapse of the North Patagonian Andes (41°30′-42°S) Fold and thrust belt Hinterland extensional tectonics North Patagonian Andes Volcanism Geochronology Volcanoes Extensional collapse Extensional tectonics Fold-and-thrust belts Geochronological determination North Patagonian Andes Pluton emplacement Structural studies Volcanism Tectonics extensional tectonics fold and thrust belt Miocene normal fault topography volcanism Andes Patagonia The hinterland zone of the North Patagonian Andes between 41° and 43°S constitutes a poorly explored sector of the Andes, where no structural studies and scarce geochronological determinations have been carried out. This paper focuses on two isolated volcanic sections hosted at the main Andes, in which field evidence indicates a common synextensional origin. Geochronological data establish that this volcanic event occurred diachronously at the innermost sector of the evolving fold and thrust belt, during middle to late Miocene times. Therefore, the event was briefly coeval and postdated compressive tectonics recognized in the deformational front and correlative to the last phase of pluton emplacement of the North Patagonian Batholith. Local-scale topographic swath profiles performed in this work reveal negative topographic anomalies where normal faults were recognized. Moreover, regional swath profiles show not only a conspicuous depressed zone at the hinterland zone, where the studied sections are located, but also anomalously high altitudes at the foreland zone. In addition, calculated orogenic volumes increase in this sector of the fold and thrust belt, which agrees with recent shortening estimations. These topographic along-strike variations, in association with late Miocene extension following the main compressive stage in the area, are explained by a supercritical stage of the orogenic wedge that would have led to focused extension at the innermost sector of the fold and thrust belt. © 2015 Elsevier B.V. 2015 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00401951_v657_n_p155_Tobal http://hdl.handle.net/20.500.12110/paper_00401951_v657_n_p155_Tobal |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Fold and thrust belt Hinterland extensional tectonics North Patagonian Andes Volcanism Geochronology Volcanoes Extensional collapse Extensional tectonics Fold-and-thrust belts Geochronological determination North Patagonian Andes Pluton emplacement Structural studies Volcanism Tectonics extensional tectonics fold and thrust belt Miocene normal fault topography volcanism Andes Patagonia |
| spellingShingle |
Fold and thrust belt Hinterland extensional tectonics North Patagonian Andes Volcanism Geochronology Volcanoes Extensional collapse Extensional tectonics Fold-and-thrust belts Geochronological determination North Patagonian Andes Pluton emplacement Structural studies Volcanism Tectonics extensional tectonics fold and thrust belt Miocene normal fault topography volcanism Andes Patagonia Middle to late Miocene extensional collapse of the North Patagonian Andes (41°30′-42°S) |
| topic_facet |
Fold and thrust belt Hinterland extensional tectonics North Patagonian Andes Volcanism Geochronology Volcanoes Extensional collapse Extensional tectonics Fold-and-thrust belts Geochronological determination North Patagonian Andes Pluton emplacement Structural studies Volcanism Tectonics extensional tectonics fold and thrust belt Miocene normal fault topography volcanism Andes Patagonia |
| description |
The hinterland zone of the North Patagonian Andes between 41° and 43°S constitutes a poorly explored sector of the Andes, where no structural studies and scarce geochronological determinations have been carried out. This paper focuses on two isolated volcanic sections hosted at the main Andes, in which field evidence indicates a common synextensional origin. Geochronological data establish that this volcanic event occurred diachronously at the innermost sector of the evolving fold and thrust belt, during middle to late Miocene times. Therefore, the event was briefly coeval and postdated compressive tectonics recognized in the deformational front and correlative to the last phase of pluton emplacement of the North Patagonian Batholith. Local-scale topographic swath profiles performed in this work reveal negative topographic anomalies where normal faults were recognized. Moreover, regional swath profiles show not only a conspicuous depressed zone at the hinterland zone, where the studied sections are located, but also anomalously high altitudes at the foreland zone. In addition, calculated orogenic volumes increase in this sector of the fold and thrust belt, which agrees with recent shortening estimations. These topographic along-strike variations, in association with late Miocene extension following the main compressive stage in the area, are explained by a supercritical stage of the orogenic wedge that would have led to focused extension at the innermost sector of the fold and thrust belt. © 2015 Elsevier B.V. |
| title |
Middle to late Miocene extensional collapse of the North Patagonian Andes (41°30′-42°S) |
| title_short |
Middle to late Miocene extensional collapse of the North Patagonian Andes (41°30′-42°S) |
| title_full |
Middle to late Miocene extensional collapse of the North Patagonian Andes (41°30′-42°S) |
| title_fullStr |
Middle to late Miocene extensional collapse of the North Patagonian Andes (41°30′-42°S) |
| title_full_unstemmed |
Middle to late Miocene extensional collapse of the North Patagonian Andes (41°30′-42°S) |
| title_sort |
middle to late miocene extensional collapse of the north patagonian andes (41°30′-42°s) |
| publishDate |
2015 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00401951_v657_n_p155_Tobal http://hdl.handle.net/20.500.12110/paper_00401951_v657_n_p155_Tobal |
| _version_ |
1768542402834857984 |