Subduction of the South Chile active spreading ridge: A 17 Ma to 3 Ma magmatic record in central Patagonia (western edge of Meseta del Lago Buenos Aires, Argentina)
International audience The Chile Triple junction is a natural laboratory to study the interactions between magmatism and tectonics during the subduction of an active spreading ridge beneath a continent. The MLBA plateau (Meseta del Lago Buenos Aires) is one of the Neogene alkali basaltic plateaus lo...
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ftunivantilles:oai:HAL:hal-00475648v1 2023-11-12T04:03:54+01:00 Subduction of the South Chile active spreading ridge: A 17 Ma to 3 Ma magmatic record in central Patagonia (western edge of Meseta del Lago Buenos Aires, Argentina) Boutonnet, E. Arnaud, Nicolas Guivel, C. Lagabrielle, Yves Scalabrino, Bruno Espinoza, F. Laboratoire de Sciences de la Terre (LST) École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL) Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) Géosciences Montpellier Université des Antilles et de la Guyane (UAG)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS) Laboratoire de Planétologie et Géodynamique UMR 6112 (LPG) Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST) Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) Departemento de Geologia Santiago 2010 https://hal.science/hal-00475648 https://doi.org/10.1016/j.jvolgeores.2009.11.022 en eng HAL CCSD Elsevier info:eu-repo/semantics/altIdentifier/doi/10.1016/j.jvolgeores.2009.11.022 hal-00475648 https://hal.science/hal-00475648 doi:10.1016/j.jvolgeores.2009.11.022 ISSN: 0377-0273 Journal of Volcanology and Geothermal Research https://hal.science/hal-00475648 Journal of Volcanology and Geothermal Research, 2010, 189 (3-4), pp.319-339. ⟨10.1016/j.jvolgeores.2009.11.022⟩ subduction spreading ridge bimodal back-arc magmatism Patagonia [SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics [SDE.MCG]Environmental Sciences/Global Changes info:eu-repo/semantics/article Journal articles 2010 ftunivantilles https://doi.org/10.1016/j.jvolgeores.2009.11.022 2023-10-24T22:34:50Z International audience The Chile Triple junction is a natural laboratory to study the interactions between magmatism and tectonics during the subduction of an active spreading ridge beneath a continent. The MLBA plateau (Meseta del Lago Buenos Aires) is one of the Neogene alkali basaltic plateaus located in the back-arc region of the Andean Cordillera at the latitude of the current Chile Triple junction. The genesis of MLBA can be related with successive opening of slabs windows beneath Patagonia: within the subducting Nazca Plate itself and between the Nazca and Antarctic plates. Detailed Ar-40/Ar-39 dating and geochemical analysis of bimodal magmatism from the western flank of the MLBA show major changes in the back-arc magmatism. which occurred between 14.5 Ma and 12.5 Ma with the transition from calc-alkaline lavas (Cerro Plomo) to alkaline lavas (MLBA) in relation with slab window opening. In a second step, at 4-3 Ma, alkaline felsic intrusions were emplaced in the western flank of the MLBA coevally with the MLBA basalts with which they are genetically related. These late OIB-like alkaline to transitional basalts were generated by partial melting of the subslab asthenosphere of the subducting Nazca plate during the opening of the South Chile spreading ridge-related slab window. These basalts differentiated with small amounts of assimilation in shallow magma chambers emplaced along transtensional to extensional zones. The close association of bimodal magmatism with extensional tectonic features in the western MLBA is a strong support to the model of Patagonian collapse event proposed to have taken place between 5 and 3 Ma as a consequence of the presence of the asthenospheric window (SCR-1 segment of South Chile Ridge) below the MLBA area. Article in Journal/Newspaper Antarc* Antarctic Université des Antilles (UAG): HAL Antarctic Patagonia Argentina Journal of Volcanology and Geothermal Research 189 3-4 319 339 |
institution |
Open Polar |
collection |
Université des Antilles (UAG): HAL |
op_collection_id |
ftunivantilles |
language |
English |
topic |
subduction spreading ridge bimodal back-arc magmatism Patagonia [SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics [SDE.MCG]Environmental Sciences/Global Changes |
spellingShingle |
subduction spreading ridge bimodal back-arc magmatism Patagonia [SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics [SDE.MCG]Environmental Sciences/Global Changes Boutonnet, E. Arnaud, Nicolas Guivel, C. Lagabrielle, Yves Scalabrino, Bruno Espinoza, F. Subduction of the South Chile active spreading ridge: A 17 Ma to 3 Ma magmatic record in central Patagonia (western edge of Meseta del Lago Buenos Aires, Argentina) |
topic_facet |
subduction spreading ridge bimodal back-arc magmatism Patagonia [SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics [SDE.MCG]Environmental Sciences/Global Changes |
description |
International audience The Chile Triple junction is a natural laboratory to study the interactions between magmatism and tectonics during the subduction of an active spreading ridge beneath a continent. The MLBA plateau (Meseta del Lago Buenos Aires) is one of the Neogene alkali basaltic plateaus located in the back-arc region of the Andean Cordillera at the latitude of the current Chile Triple junction. The genesis of MLBA can be related with successive opening of slabs windows beneath Patagonia: within the subducting Nazca Plate itself and between the Nazca and Antarctic plates. Detailed Ar-40/Ar-39 dating and geochemical analysis of bimodal magmatism from the western flank of the MLBA show major changes in the back-arc magmatism. which occurred between 14.5 Ma and 12.5 Ma with the transition from calc-alkaline lavas (Cerro Plomo) to alkaline lavas (MLBA) in relation with slab window opening. In a second step, at 4-3 Ma, alkaline felsic intrusions were emplaced in the western flank of the MLBA coevally with the MLBA basalts with which they are genetically related. These late OIB-like alkaline to transitional basalts were generated by partial melting of the subslab asthenosphere of the subducting Nazca plate during the opening of the South Chile spreading ridge-related slab window. These basalts differentiated with small amounts of assimilation in shallow magma chambers emplaced along transtensional to extensional zones. The close association of bimodal magmatism with extensional tectonic features in the western MLBA is a strong support to the model of Patagonian collapse event proposed to have taken place between 5 and 3 Ma as a consequence of the presence of the asthenospheric window (SCR-1 segment of South Chile Ridge) below the MLBA area. |
author2 |
Laboratoire de Sciences de la Terre (LST) École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL) Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) Géosciences Montpellier Université des Antilles et de la Guyane (UAG)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS) Laboratoire de Planétologie et Géodynamique UMR 6112 (LPG) Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST) Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) Departemento de Geologia Santiago |
format |
Article in Journal/Newspaper |
author |
Boutonnet, E. Arnaud, Nicolas Guivel, C. Lagabrielle, Yves Scalabrino, Bruno Espinoza, F. |
author_facet |
Boutonnet, E. Arnaud, Nicolas Guivel, C. Lagabrielle, Yves Scalabrino, Bruno Espinoza, F. |
author_sort |
Boutonnet, E. |
title |
Subduction of the South Chile active spreading ridge: A 17 Ma to 3 Ma magmatic record in central Patagonia (western edge of Meseta del Lago Buenos Aires, Argentina) |
title_short |
Subduction of the South Chile active spreading ridge: A 17 Ma to 3 Ma magmatic record in central Patagonia (western edge of Meseta del Lago Buenos Aires, Argentina) |
title_full |
Subduction of the South Chile active spreading ridge: A 17 Ma to 3 Ma magmatic record in central Patagonia (western edge of Meseta del Lago Buenos Aires, Argentina) |
title_fullStr |
Subduction of the South Chile active spreading ridge: A 17 Ma to 3 Ma magmatic record in central Patagonia (western edge of Meseta del Lago Buenos Aires, Argentina) |
title_full_unstemmed |
Subduction of the South Chile active spreading ridge: A 17 Ma to 3 Ma magmatic record in central Patagonia (western edge of Meseta del Lago Buenos Aires, Argentina) |
title_sort |
subduction of the south chile active spreading ridge: a 17 ma to 3 ma magmatic record in central patagonia (western edge of meseta del lago buenos aires, argentina) |
publisher |
HAL CCSD |
publishDate |
2010 |
url |
https://hal.science/hal-00475648 https://doi.org/10.1016/j.jvolgeores.2009.11.022 |
geographic |
Antarctic Patagonia Argentina |
geographic_facet |
Antarctic Patagonia Argentina |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_source |
ISSN: 0377-0273 Journal of Volcanology and Geothermal Research https://hal.science/hal-00475648 Journal of Volcanology and Geothermal Research, 2010, 189 (3-4), pp.319-339. ⟨10.1016/j.jvolgeores.2009.11.022⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1016/j.jvolgeores.2009.11.022 hal-00475648 https://hal.science/hal-00475648 doi:10.1016/j.jvolgeores.2009.11.022 |
op_doi |
https://doi.org/10.1016/j.jvolgeores.2009.11.022 |
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Journal of Volcanology and Geothermal Research |
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189 |
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3-4 |
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339 |
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