Andean deformation at the cordón del Hielo Azul, El Bolsón, Río Negro (Argentina). Implications for the tectonic evolution of the north Patagonian Andes
This geological study, carried out in the Cordón del Hielo Azul, west of the El Bolsón town (Río Negro province, Argentina), shows the different relationships between the Early Jurassic cordilleran volcanosedimentary sequence, the Middle-Upper Jurassic Cordilleran Patagonian Batholith and the Cenozo...
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2012
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_07187092_v39_n3_p442_Tobal http://hdl.handle.net/20.500.12110/paper_07187092_v39_n3_p442_Tobal |
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paper:paper_07187092_v39_n3_p442_Tobal2023-06-08T15:43:15Z Andean deformation at the cordón del Hielo Azul, El Bolsón, Río Negro (Argentina). Implications for the tectonic evolution of the north Patagonian Andes Andean tectonics Argentina Fold and thrust belt North Patagonian Andes Structure Andean orogeny deformation fold and thrust belt Jurassic Oligocene outcrop sedimentary sequence structural analysis tectonic evolution thrust fault volcanic rock Andes Argentina Patagonia This geological study, carried out in the Cordón del Hielo Azul, west of the El Bolsón town (Río Negro province, Argentina), shows the different relationships between the Early Jurassic cordilleran volcanosedimentary sequence, the Middle-Upper Jurassic Cordilleran Patagonian Batholith and the Cenozoic volcanic rocks of the Ventana Formation exposed in the Patagonian Cordillera of Río Negro. Through structural analysis, a series of previously unknown complex deformational structures have been identified. It has been observed that the sequence of volcanic rocks that outcrop on the Cerro Lindo, just west of El Bolsón, is bounded by a backthrust in the eastern side and by an out of sequence thrust to the west, two other thrusts affect the sequence, with associated folded structures. To the north, on the west side of Cerro Hielo Azul, these Lower Jurassic volcanic rocks are in tectonic contact with the Cenozoic rocks of the Ventana Formation. Based on these observations, we inferred that an extensional fault controlled deposition of the Cenozoic volcanic rocks, being subsequently inverted, superimposing these rocks on the Jurassic volcanics. The different recognized faults exerted a first order control in the building of the mountain front and are robust evidence to establish the tectonic framework and uplift history of the North Patagonian Andes. This deformation took place from the Eocene to the Late Miocene. A pre-Oligocene contractional pulse led to the development of a thin-skinned fold and thrust belt affecting the Jurassic volcanics. During the Oligocene a regional extensional event resulted in the formation of basins such as the one recognized on Cerro Silvia, where the Ventana Formation crops out. A second contractional pulse took place during the Miocene and led to the development of a thick-skinned fold and thrust belt with deep faults that built the present mountain front. 2012 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_07187092_v39_n3_p442_Tobal http://hdl.handle.net/20.500.12110/paper_07187092_v39_n3_p442_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 |
Andean tectonics Argentina Fold and thrust belt North Patagonian Andes Structure Andean orogeny deformation fold and thrust belt Jurassic Oligocene outcrop sedimentary sequence structural analysis tectonic evolution thrust fault volcanic rock Andes Argentina Patagonia |
| spellingShingle |
Andean tectonics Argentina Fold and thrust belt North Patagonian Andes Structure Andean orogeny deformation fold and thrust belt Jurassic Oligocene outcrop sedimentary sequence structural analysis tectonic evolution thrust fault volcanic rock Andes Argentina Patagonia Andean deformation at the cordón del Hielo Azul, El Bolsón, Río Negro (Argentina). Implications for the tectonic evolution of the north Patagonian Andes |
| topic_facet |
Andean tectonics Argentina Fold and thrust belt North Patagonian Andes Structure Andean orogeny deformation fold and thrust belt Jurassic Oligocene outcrop sedimentary sequence structural analysis tectonic evolution thrust fault volcanic rock Andes Argentina Patagonia |
| description |
This geological study, carried out in the Cordón del Hielo Azul, west of the El Bolsón town (Río Negro province, Argentina), shows the different relationships between the Early Jurassic cordilleran volcanosedimentary sequence, the Middle-Upper Jurassic Cordilleran Patagonian Batholith and the Cenozoic volcanic rocks of the Ventana Formation exposed in the Patagonian Cordillera of Río Negro. Through structural analysis, a series of previously unknown complex deformational structures have been identified. It has been observed that the sequence of volcanic rocks that outcrop on the Cerro Lindo, just west of El Bolsón, is bounded by a backthrust in the eastern side and by an out of sequence thrust to the west, two other thrusts affect the sequence, with associated folded structures. To the north, on the west side of Cerro Hielo Azul, these Lower Jurassic volcanic rocks are in tectonic contact with the Cenozoic rocks of the Ventana Formation. Based on these observations, we inferred that an extensional fault controlled deposition of the Cenozoic volcanic rocks, being subsequently inverted, superimposing these rocks on the Jurassic volcanics. The different recognized faults exerted a first order control in the building of the mountain front and are robust evidence to establish the tectonic framework and uplift history of the North Patagonian Andes. This deformation took place from the Eocene to the Late Miocene. A pre-Oligocene contractional pulse led to the development of a thin-skinned fold and thrust belt affecting the Jurassic volcanics. During the Oligocene a regional extensional event resulted in the formation of basins such as the one recognized on Cerro Silvia, where the Ventana Formation crops out. A second contractional pulse took place during the Miocene and led to the development of a thick-skinned fold and thrust belt with deep faults that built the present mountain front. |
| title |
Andean deformation at the cordón del Hielo Azul, El Bolsón, Río Negro (Argentina). Implications for the tectonic evolution of the north Patagonian Andes |
| title_short |
Andean deformation at the cordón del Hielo Azul, El Bolsón, Río Negro (Argentina). Implications for the tectonic evolution of the north Patagonian Andes |
| title_full |
Andean deformation at the cordón del Hielo Azul, El Bolsón, Río Negro (Argentina). Implications for the tectonic evolution of the north Patagonian Andes |
| title_fullStr |
Andean deformation at the cordón del Hielo Azul, El Bolsón, Río Negro (Argentina). Implications for the tectonic evolution of the north Patagonian Andes |
| title_full_unstemmed |
Andean deformation at the cordón del Hielo Azul, El Bolsón, Río Negro (Argentina). Implications for the tectonic evolution of the north Patagonian Andes |
| title_sort |
andean deformation at the cordón del hielo azul, el bolsón, río negro (argentina). implications for the tectonic evolution of the north patagonian andes |
| publishDate |
2012 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_07187092_v39_n3_p442_Tobal http://hdl.handle.net/20.500.12110/paper_07187092_v39_n3_p442_Tobal |
| _version_ |
1768545603355148288 |