Late Oligocene-early Miocene submarine volcanism and deep-marine sedimentation in an extensional basin of southern Chile: Implications for the tectonic development of the North Patagonian Andes

The Chilean margin has been used as the model of an ocean-continent convergent system dominated by compression and active mountain building as a consequence of the strong mechanical coupling between the upper and the lower plates. The Andean Cordillera, however, shows evidence of alternating phases...

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Autores principales:	Folguera, Andrés, Gianni, Guido Martin
Publicado:	2016
Materias:	Geochemistry Lead Petrography Sedimentology Structural geology Submarines Tectonics Convergent systems Extensional deformation Extensional tectonics Mechanical coupling Southern south america Submarine volcanism Tectonic development U-Pb geochronology Geochronology crustal thinning deep sea extensional tectonics Miocene Oligocene sedimentation submarine volcano tectonic evolution volcanism Andes Patagonia
Acceso en línea:	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00167606_v128_n5-6_p807_Encinas http://hdl.handle.net/20.500.12110/paper_00167606_v128_n5-6_p807_Encinas
Aporte de:	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires

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spelling	paper:paper_00167606_v128_n5-6_p807_Encinas2025-07-30T17:21:29Z Late Oligocene-early Miocene submarine volcanism and deep-marine sedimentation in an extensional basin of southern Chile: Implications for the tectonic development of the North Patagonian Andes Folguera, Andrés Gianni, Guido Martin Geochemistry Lead Petrography Sedimentology Structural geology Submarines Tectonics Convergent systems Extensional deformation Extensional tectonics Mechanical coupling Southern south america Submarine volcanism Tectonic development U-Pb geochronology Geochronology crustal thinning deep sea extensional tectonics Miocene Oligocene sedimentation submarine volcano tectonic evolution volcanism Andes Patagonia The Chilean margin has been used as the model of an ocean-continent convergent system dominated by compression and active mountain building as a consequence of the strong mechanical coupling between the upper and the lower plates. The Andean Cordillera, however, shows evidence of alternating phases of compressional and extensional deformation. Volcano-sedimentary marine strata in the Aysén region of southern Chile contribute to an understanding of the causes of extensional tectonics and crustal thinning that occurred in the Andean orogeny because these deposits constitute the only reliable record of submarine suprasubduction volcanism during the Cenozoic in southern South America. In order to discern the age and tectono-sedimentary setting of these strata, referred to as the Traiguén Formation, we integrated sedimentology, ichnology, petrography, geochemistry, structural geology, foraminiferal micropaleontology, and U-Pb geochronology. Our results indicate that the Traiguén Formation was deposited in a deep-marine extensional basin during the late Oligocene-earliest Miocene. The geochemistry and petrography of the pillow basalts suggest that they formed in a convergent margin on a thinned crust rather than at an oceanic spreading center. We attribute the origin of the Traiguén Basin to a transient period of slab rollback and vigorous asthenospheric wedge circulation that was caused by an increase in trench-normal convergence rate at ca. 26-28 Ma and that resulted in a regional event of extension and widespread volcanism. © 2015 Geological Society of America. Fil:Folguera, A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Gianni, G. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2016 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00167606_v128_n5-6_p807_Encinas http://hdl.handle.net/20.500.12110/paper_00167606_v128_n5-6_p807_Encinas
institution	Universidad de Buenos Aires
institution_str	I-28
repository_str	R-134
collection	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic	Geochemistry Lead Petrography Sedimentology Structural geology Submarines Tectonics Convergent systems Extensional deformation Extensional tectonics Mechanical coupling Southern south america Submarine volcanism Tectonic development U-Pb geochronology Geochronology crustal thinning deep sea extensional tectonics Miocene Oligocene sedimentation submarine volcano tectonic evolution volcanism Andes Patagonia
spellingShingle	Geochemistry Lead Petrography Sedimentology Structural geology Submarines Tectonics Convergent systems Extensional deformation Extensional tectonics Mechanical coupling Southern south america Submarine volcanism Tectonic development U-Pb geochronology Geochronology crustal thinning deep sea extensional tectonics Miocene Oligocene sedimentation submarine volcano tectonic evolution volcanism Andes Patagonia Folguera, Andrés Gianni, Guido Martin Late Oligocene-early Miocene submarine volcanism and deep-marine sedimentation in an extensional basin of southern Chile: Implications for the tectonic development of the North Patagonian Andes
topic_facet	Geochemistry Lead Petrography Sedimentology Structural geology Submarines Tectonics Convergent systems Extensional deformation Extensional tectonics Mechanical coupling Southern south america Submarine volcanism Tectonic development U-Pb geochronology Geochronology crustal thinning deep sea extensional tectonics Miocene Oligocene sedimentation submarine volcano tectonic evolution volcanism Andes Patagonia
description	The Chilean margin has been used as the model of an ocean-continent convergent system dominated by compression and active mountain building as a consequence of the strong mechanical coupling between the upper and the lower plates. The Andean Cordillera, however, shows evidence of alternating phases of compressional and extensional deformation. Volcano-sedimentary marine strata in the Aysén region of southern Chile contribute to an understanding of the causes of extensional tectonics and crustal thinning that occurred in the Andean orogeny because these deposits constitute the only reliable record of submarine suprasubduction volcanism during the Cenozoic in southern South America. In order to discern the age and tectono-sedimentary setting of these strata, referred to as the Traiguén Formation, we integrated sedimentology, ichnology, petrography, geochemistry, structural geology, foraminiferal micropaleontology, and U-Pb geochronology. Our results indicate that the Traiguén Formation was deposited in a deep-marine extensional basin during the late Oligocene-earliest Miocene. The geochemistry and petrography of the pillow basalts suggest that they formed in a convergent margin on a thinned crust rather than at an oceanic spreading center. We attribute the origin of the Traiguén Basin to a transient period of slab rollback and vigorous asthenospheric wedge circulation that was caused by an increase in trench-normal convergence rate at ca. 26-28 Ma and that resulted in a regional event of extension and widespread volcanism. © 2015 Geological Society of America.
author	Folguera, Andrés Gianni, Guido Martin
author_facet	Folguera, Andrés Gianni, Guido Martin
author_sort	Folguera, Andrés
title	Late Oligocene-early Miocene submarine volcanism and deep-marine sedimentation in an extensional basin of southern Chile: Implications for the tectonic development of the North Patagonian Andes
title_short	Late Oligocene-early Miocene submarine volcanism and deep-marine sedimentation in an extensional basin of southern Chile: Implications for the tectonic development of the North Patagonian Andes
title_full	Late Oligocene-early Miocene submarine volcanism and deep-marine sedimentation in an extensional basin of southern Chile: Implications for the tectonic development of the North Patagonian Andes
title_fullStr	Late Oligocene-early Miocene submarine volcanism and deep-marine sedimentation in an extensional basin of southern Chile: Implications for the tectonic development of the North Patagonian Andes
title_full_unstemmed	Late Oligocene-early Miocene submarine volcanism and deep-marine sedimentation in an extensional basin of southern Chile: Implications for the tectonic development of the North Patagonian Andes
title_sort	late oligocene-early miocene submarine volcanism and deep-marine sedimentation in an extensional basin of southern chile: implications for the tectonic development of the north patagonian andes
publishDate	2016
url	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00167606_v128_n5-6_p807_Encinas http://hdl.handle.net/20.500.12110/paper_00167606_v128_n5-6_p807_Encinas
work_keys_str_mv	AT folgueraandres lateoligoceneearlymiocenesubmarinevolcanismanddeepmarinesedimentationinanextensionalbasinofsouthernchileimplicationsforthetectonicdevelopmentofthenorthpatagonianandes AT gianniguidomartin lateoligoceneearlymiocenesubmarinevolcanismanddeepmarinesedimentationinanextensionalbasinofsouthernchileimplicationsforthetectonicdevelopmentofthenorthpatagonianandes
_version_	1840325785379930112

Late Oligocene-early Miocene submarine volcanism and deep-marine sedimentation in an extensional basin of southern Chile: Implications for the tectonic development of the North Patagonian Andes

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