Geophysical evidence for lithospheric scale asymmetry and inherited mantle in the SE Brazilian-Angola and Newfoundland-Iberia rifted margins
International audience Rift systems in the central South Atlantic and the southern Northern Atlantic margins exhibit anomalous wide ocean-continent transitions, extreme thinning of the continental crust, and scarce volcanism indicative of low magmatic budgets during rifting and breakup, characterist...
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Online Access: | https://insu.hal.science/insu-04198302 https://doi.org/10.1016/j.jsames.2023.104214 |
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ftinsu:oai:HAL:insu-04198302v1 2023-10-09T21:53:40+02:00 Geophysical evidence for lithospheric scale asymmetry and inherited mantle in the SE Brazilian-Angola and Newfoundland-Iberia rifted margins Szameitat, Luizemara Soares Alves Heilbron, Monica Aragão, Maria Alice Nascimento Fagundes De Manatschal, Gianreto Ferreira, Francisco José Fonseca Bongiolo, Alessandra de Barros E. Silva Santos, Anderson Costa Dos Mohriak, Webster Ueipass Institut de physique du globe de Strasbourg (IPGS) Institut national des sciences de l'Univers (INSU - CNRS)-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS) Ecole et Observatoire des Sciences de la Terre (EOST) Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) 2023 https://insu.hal.science/insu-04198302 https://doi.org/10.1016/j.jsames.2023.104214 en eng HAL CCSD Elsevier info:eu-repo/semantics/altIdentifier/doi/10.1016/j.jsames.2023.104214 insu-04198302 https://insu.hal.science/insu-04198302 BIBCODE: 2023JSAES.12304214S doi:10.1016/j.jsames.2023.104214 ISSN: 0895-9811 EISSN: 1873-0647 Journal of South American Earth Sciences https://insu.hal.science/insu-04198302 Journal of South American Earth Sciences, 2023, 123, ⟨10.1016/j.jsames.2023.104214⟩ Continental lithospheric breakup Subcontinental lithospheric mantle Tectonic inheritance Atlantic ocean Magma-poor margin [SDU]Sciences of the Universe [physics] info:eu-repo/semantics/article Journal articles 2023 ftinsu https://doi.org/10.1016/j.jsames.2023.104214 2023-09-13T16:23:56Z International audience Rift systems in the central South Atlantic and the southern Northern Atlantic margins exhibit anomalous wide ocean-continent transitions, extreme thinning of the continental crust, and scarce volcanism indicative of low magmatic budgets during rifting and breakup, characteristic of magma-poor rifted margins. While numerous studies investigated the crustal architecture at these magma-poor rifted margins, the nature of the underlying mantle lithosphere remains virtually unknown. In this work, we have interpreted seismic tomography and electromagnetic data with the aim of comparing large-scale aspects and mantle geophysical anomalies at these conjugate rifted margins. The data exhibits low electrical conductivity and high P-wave velocity in the mantle underlying the Iberia and the Angolan margins, while the Newfoundland and SE-Brazil margins show a lack of high-velocity mantle and exhibit higher electrical conductivity. The P-wave tomography values at middle lithospheric depths are suggestive of an oceanward lateral continuity of rigid lithospheric mantle at both the Iberian and Angola margins that may correspond to an anomalous mantle. Rifting-induced delamination at the onset of Atlantic opening is supported by previous geochemical studies. In addition, low electrical conductivity areas may indicate dry mantle conditions, which can be caused by inherited subcontinental mantle, and/or pre-to syn-rift magmatic extraction. A lack of high-velocity and high electrical conductivity in the mantle under the Newfoundland and Santos-Campos margins suggest a relatively weaker and newly formed mantle, in agreement with the removing and/or initial absence of a strong middle-to-lower inherited lithosphere beneath those margins. Therefore, the geophysical observations support different types of the nature of the middle mantle lithospheres flooring the two conjugate, magma-poor rifted margins. Article in Journal/Newspaper Newfoundland Institut national des sciences de l'Univers: HAL-INSU Journal of South American Earth Sciences 123 104214 |
institution |
Open Polar |
collection |
Institut national des sciences de l'Univers: HAL-INSU |
op_collection_id |
ftinsu |
language |
English |
topic |
Continental lithospheric breakup Subcontinental lithospheric mantle Tectonic inheritance Atlantic ocean Magma-poor margin [SDU]Sciences of the Universe [physics] |
spellingShingle |
Continental lithospheric breakup Subcontinental lithospheric mantle Tectonic inheritance Atlantic ocean Magma-poor margin [SDU]Sciences of the Universe [physics] Szameitat, Luizemara Soares Alves Heilbron, Monica Aragão, Maria Alice Nascimento Fagundes De Manatschal, Gianreto Ferreira, Francisco José Fonseca Bongiolo, Alessandra de Barros E. Silva Santos, Anderson Costa Dos Mohriak, Webster Ueipass Geophysical evidence for lithospheric scale asymmetry and inherited mantle in the SE Brazilian-Angola and Newfoundland-Iberia rifted margins |
topic_facet |
Continental lithospheric breakup Subcontinental lithospheric mantle Tectonic inheritance Atlantic ocean Magma-poor margin [SDU]Sciences of the Universe [physics] |
description |
International audience Rift systems in the central South Atlantic and the southern Northern Atlantic margins exhibit anomalous wide ocean-continent transitions, extreme thinning of the continental crust, and scarce volcanism indicative of low magmatic budgets during rifting and breakup, characteristic of magma-poor rifted margins. While numerous studies investigated the crustal architecture at these magma-poor rifted margins, the nature of the underlying mantle lithosphere remains virtually unknown. In this work, we have interpreted seismic tomography and electromagnetic data with the aim of comparing large-scale aspects and mantle geophysical anomalies at these conjugate rifted margins. The data exhibits low electrical conductivity and high P-wave velocity in the mantle underlying the Iberia and the Angolan margins, while the Newfoundland and SE-Brazil margins show a lack of high-velocity mantle and exhibit higher electrical conductivity. The P-wave tomography values at middle lithospheric depths are suggestive of an oceanward lateral continuity of rigid lithospheric mantle at both the Iberian and Angola margins that may correspond to an anomalous mantle. Rifting-induced delamination at the onset of Atlantic opening is supported by previous geochemical studies. In addition, low electrical conductivity areas may indicate dry mantle conditions, which can be caused by inherited subcontinental mantle, and/or pre-to syn-rift magmatic extraction. A lack of high-velocity and high electrical conductivity in the mantle under the Newfoundland and Santos-Campos margins suggest a relatively weaker and newly formed mantle, in agreement with the removing and/or initial absence of a strong middle-to-lower inherited lithosphere beneath those margins. Therefore, the geophysical observations support different types of the nature of the middle mantle lithospheres flooring the two conjugate, magma-poor rifted margins. |
author2 |
Institut de physique du globe de Strasbourg (IPGS) Institut national des sciences de l'Univers (INSU - CNRS)-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS) Ecole et Observatoire des Sciences de la Terre (EOST) Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) |
format |
Article in Journal/Newspaper |
author |
Szameitat, Luizemara Soares Alves Heilbron, Monica Aragão, Maria Alice Nascimento Fagundes De Manatschal, Gianreto Ferreira, Francisco José Fonseca Bongiolo, Alessandra de Barros E. Silva Santos, Anderson Costa Dos Mohriak, Webster Ueipass |
author_facet |
Szameitat, Luizemara Soares Alves Heilbron, Monica Aragão, Maria Alice Nascimento Fagundes De Manatschal, Gianreto Ferreira, Francisco José Fonseca Bongiolo, Alessandra de Barros E. Silva Santos, Anderson Costa Dos Mohriak, Webster Ueipass |
author_sort |
Szameitat, Luizemara Soares Alves |
title |
Geophysical evidence for lithospheric scale asymmetry and inherited mantle in the SE Brazilian-Angola and Newfoundland-Iberia rifted margins |
title_short |
Geophysical evidence for lithospheric scale asymmetry and inherited mantle in the SE Brazilian-Angola and Newfoundland-Iberia rifted margins |
title_full |
Geophysical evidence for lithospheric scale asymmetry and inherited mantle in the SE Brazilian-Angola and Newfoundland-Iberia rifted margins |
title_fullStr |
Geophysical evidence for lithospheric scale asymmetry and inherited mantle in the SE Brazilian-Angola and Newfoundland-Iberia rifted margins |
title_full_unstemmed |
Geophysical evidence for lithospheric scale asymmetry and inherited mantle in the SE Brazilian-Angola and Newfoundland-Iberia rifted margins |
title_sort |
geophysical evidence for lithospheric scale asymmetry and inherited mantle in the se brazilian-angola and newfoundland-iberia rifted margins |
publisher |
HAL CCSD |
publishDate |
2023 |
url |
https://insu.hal.science/insu-04198302 https://doi.org/10.1016/j.jsames.2023.104214 |
genre |
Newfoundland |
genre_facet |
Newfoundland |
op_source |
ISSN: 0895-9811 EISSN: 1873-0647 Journal of South American Earth Sciences https://insu.hal.science/insu-04198302 Journal of South American Earth Sciences, 2023, 123, ⟨10.1016/j.jsames.2023.104214⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1016/j.jsames.2023.104214 insu-04198302 https://insu.hal.science/insu-04198302 BIBCODE: 2023JSAES.12304214S doi:10.1016/j.jsames.2023.104214 |
op_doi |
https://doi.org/10.1016/j.jsames.2023.104214 |
container_title |
Journal of South American Earth Sciences |
container_volume |
123 |
container_start_page |
104214 |
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1779316974706229248 |