Brazilian and African passive margins of the Central Segment of the South Atlantic Ocean: Kinematic constraints
International audience The thinning of passive continental margins is usually explained by models using pure stretching or simple shear. These models imply hypothetical extensional structures and large horizontal movements between the two conjugate margins (more than 250 km for the Brazilian and Ang...
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ftunivbrest:oai:HAL:insu-00446577v1 2024-04-28T08:38:12+00:00 Brazilian and African passive margins of the Central Segment of the South Atlantic Ocean: Kinematic constraints Aslanian, Daniel Moulin, Maryline Olivet, Jean-Louis Unternehr, Patrick Matias, L. Bache, François Rabineau, Marina Nouzé, Hervé Klingelhoefer, Frauke Contrucci, Isabelle Labails, Cinthia Unité Géosciences Marines (GM) Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER) LATTEXLaboratorio de Tectonofisica e tectonica experimental Universidade de Lisboa = University of Lisbon (ULISBOA) Total Exploration Production TOTAL FINA ELF Centro de Geofisica Lisboa (CGUL) Domaines Océaniques (LDO) Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Observatoire des Sciences de l'Univers-Institut d'écologie et environnement-Centre National de la Recherche Scientifique (CNRS) Université européenne de Bretagne - European University of Brittany (UEB) Laboratoire Environnement Géomécanique et Ouvrages (LAEGO) Institut National Polytechnique de Lorraine (INPL) Geological Survey of Norway (NGU) 2009-04-01 https://insu.hal.science/insu-00446577 https://doi.org/10.1016/j.tecto.2008.12.016 en eng HAL CCSD Elsevier info:eu-repo/semantics/altIdentifier/doi/10.1016/j.tecto.2008.12.016 insu-00446577 https://insu.hal.science/insu-00446577 doi:10.1016/j.tecto.2008.12.016 ISSN: 0040-1951 EISSN: 1879-3266 Tectonophysics https://insu.hal.science/insu-00446577 Tectonophysics, 2009, 468 (1-4), pp.98-112. ⟨10.1016/j.tecto.2008.12.016⟩ South Atlantic Ocean Passive continental margin Kinematic reconstruction and constraints Thinning processes Lower continental crust [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph] [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph] [SDE.MCG]Environmental Sciences/Global Changes info:eu-repo/semantics/article Journal articles 2009 ftunivbrest https://doi.org/10.1016/j.tecto.2008.12.016 2024-04-10T23:46:14Z International audience The thinning of passive continental margins is usually explained by models using pure stretching or simple shear. These models imply hypothetical extensional structures and large horizontal movements between the two conjugate margins (more than 250 km for the Brazilian and Angolan Margins). Refraction/reflection data together with the most recent and tightest pre-opening fit using continental and oceanic, geological and geophysical constraints show that the substratum of the sag basin is divided into an autochthonous part (upper continental crust) and an allochthonous part (exhumed material). The thinning process, which evolves in an elevated position of the system until at least the break-up, seems to be depth dependent and to mainly concern the lower/middle crust, which we postulate is exhumed. This exhumation does not explain the entire thinning of the system: horizontal motions cannot alone explain the formation of the huge Angolan–Brazilian Basin. Similar observations are made on the whole Central Segment of the South Atlantic Ocean. Part of the lower continental crust is still missing and it seems most improbable that the continental crust maintains its integrity throughout the thinning process. Article in Journal/Newspaper South Atlantic Ocean Université de Bretagne Occidentale: HAL Tectonophysics 468 1-4 98 112 |
institution |
Open Polar |
collection |
Université de Bretagne Occidentale: HAL |
op_collection_id |
ftunivbrest |
language |
English |
topic |
South Atlantic Ocean Passive continental margin Kinematic reconstruction and constraints Thinning processes Lower continental crust [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph] [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph] [SDE.MCG]Environmental Sciences/Global Changes |
spellingShingle |
South Atlantic Ocean Passive continental margin Kinematic reconstruction and constraints Thinning processes Lower continental crust [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph] [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph] [SDE.MCG]Environmental Sciences/Global Changes Aslanian, Daniel Moulin, Maryline Olivet, Jean-Louis Unternehr, Patrick Matias, L. Bache, François Rabineau, Marina Nouzé, Hervé Klingelhoefer, Frauke Contrucci, Isabelle Labails, Cinthia Brazilian and African passive margins of the Central Segment of the South Atlantic Ocean: Kinematic constraints |
topic_facet |
South Atlantic Ocean Passive continental margin Kinematic reconstruction and constraints Thinning processes Lower continental crust [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph] [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph] [SDE.MCG]Environmental Sciences/Global Changes |
description |
International audience The thinning of passive continental margins is usually explained by models using pure stretching or simple shear. These models imply hypothetical extensional structures and large horizontal movements between the two conjugate margins (more than 250 km for the Brazilian and Angolan Margins). Refraction/reflection data together with the most recent and tightest pre-opening fit using continental and oceanic, geological and geophysical constraints show that the substratum of the sag basin is divided into an autochthonous part (upper continental crust) and an allochthonous part (exhumed material). The thinning process, which evolves in an elevated position of the system until at least the break-up, seems to be depth dependent and to mainly concern the lower/middle crust, which we postulate is exhumed. This exhumation does not explain the entire thinning of the system: horizontal motions cannot alone explain the formation of the huge Angolan–Brazilian Basin. Similar observations are made on the whole Central Segment of the South Atlantic Ocean. Part of the lower continental crust is still missing and it seems most improbable that the continental crust maintains its integrity throughout the thinning process. |
author2 |
Unité Géosciences Marines (GM) Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER) LATTEXLaboratorio de Tectonofisica e tectonica experimental Universidade de Lisboa = University of Lisbon (ULISBOA) Total Exploration Production TOTAL FINA ELF Centro de Geofisica Lisboa (CGUL) Domaines Océaniques (LDO) Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Observatoire des Sciences de l'Univers-Institut d'écologie et environnement-Centre National de la Recherche Scientifique (CNRS) Université européenne de Bretagne - European University of Brittany (UEB) Laboratoire Environnement Géomécanique et Ouvrages (LAEGO) Institut National Polytechnique de Lorraine (INPL) Geological Survey of Norway (NGU) |
format |
Article in Journal/Newspaper |
author |
Aslanian, Daniel Moulin, Maryline Olivet, Jean-Louis Unternehr, Patrick Matias, L. Bache, François Rabineau, Marina Nouzé, Hervé Klingelhoefer, Frauke Contrucci, Isabelle Labails, Cinthia |
author_facet |
Aslanian, Daniel Moulin, Maryline Olivet, Jean-Louis Unternehr, Patrick Matias, L. Bache, François Rabineau, Marina Nouzé, Hervé Klingelhoefer, Frauke Contrucci, Isabelle Labails, Cinthia |
author_sort |
Aslanian, Daniel |
title |
Brazilian and African passive margins of the Central Segment of the South Atlantic Ocean: Kinematic constraints |
title_short |
Brazilian and African passive margins of the Central Segment of the South Atlantic Ocean: Kinematic constraints |
title_full |
Brazilian and African passive margins of the Central Segment of the South Atlantic Ocean: Kinematic constraints |
title_fullStr |
Brazilian and African passive margins of the Central Segment of the South Atlantic Ocean: Kinematic constraints |
title_full_unstemmed |
Brazilian and African passive margins of the Central Segment of the South Atlantic Ocean: Kinematic constraints |
title_sort |
brazilian and african passive margins of the central segment of the south atlantic ocean: kinematic constraints |
publisher |
HAL CCSD |
publishDate |
2009 |
url |
https://insu.hal.science/insu-00446577 https://doi.org/10.1016/j.tecto.2008.12.016 |
genre |
South Atlantic Ocean |
genre_facet |
South Atlantic Ocean |
op_source |
ISSN: 0040-1951 EISSN: 1879-3266 Tectonophysics https://insu.hal.science/insu-00446577 Tectonophysics, 2009, 468 (1-4), pp.98-112. ⟨10.1016/j.tecto.2008.12.016⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1016/j.tecto.2008.12.016 insu-00446577 https://insu.hal.science/insu-00446577 doi:10.1016/j.tecto.2008.12.016 |
op_doi |
https://doi.org/10.1016/j.tecto.2008.12.016 |
container_title |
Tectonophysics |
container_volume |
468 |
container_issue |
1-4 |
container_start_page |
98 |
op_container_end_page |
112 |
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1797569358934835200 |