Necking of the Lithosphere: A Reappraisal of Basic Concepts With Thermo-Mechanical Numerical Modeling
International audience We investigate lithosphere necking using two-dimensional thermo-mechanical numerical simulations without strain softening or weakening mechanisms. The models have an initial small sinusoidal perturbation of the Moho depth, whose wavelength corresponds to the model width. Appli...
Published in: | Journal of Geophysical Research: Solid Earth |
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Online Access: | https://hal.archives-ouvertes.fr/hal-01893589 https://hal.archives-ouvertes.fr/hal-01893589/document https://hal.archives-ouvertes.fr/hal-01893589/file/2017JB014155.pdf https://doi.org/10.1029/2017JB014155 |
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ftunivnantes:oai:HAL:hal-01893589v1 2023-05-15T17:22:44+02:00 Necking of the Lithosphere: A Reappraisal of Basic Concepts With Thermo-Mechanical Numerical Modeling Chenin, Pauline Schmalholz, Stefan Markus Manatschal, Gianreto Karner, Garry Institut de physique du globe de Strasbourg (IPGS) Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) Université de Strasbourg (UNISTRA) Université de Lausanne = University of Lausanne (UNIL) Ecole et Observatoire des Sciences de la Terre (EOST) Now at ExxonMobil Exploration Company 2018-05 https://hal.archives-ouvertes.fr/hal-01893589 https://hal.archives-ouvertes.fr/hal-01893589/document https://hal.archives-ouvertes.fr/hal-01893589/file/2017JB014155.pdf https://doi.org/10.1029/2017JB014155 en eng HAL CCSD American Geophysical Union info:eu-repo/semantics/altIdentifier/doi/10.1029/2017JB014155 hal-01893589 https://hal.archives-ouvertes.fr/hal-01893589 https://hal.archives-ouvertes.fr/hal-01893589/document https://hal.archives-ouvertes.fr/hal-01893589/file/2017JB014155.pdf doi:10.1029/2017JB014155 http://hal.archives-ouvertes.fr/licences/copyright/ info:eu-repo/semantics/OpenAccess ISSN: 2169-9313 EISSN: 2169-9356 Journal of Geophysical Research : Solid Earth https://hal.archives-ouvertes.fr/hal-01893589 Journal of Geophysical Research : Solid Earth, American Geophysical Union, 2018, 123 (6), pp.5279-5299. ⟨10.1029/2017JB014155⟩ Rift Necking Numerical modeling [SDU.STU]Sciences of the Universe [physics]/Earth Sciences [SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics info:eu-repo/semantics/article Journal articles 2018 ftunivnantes https://doi.org/10.1029/2017JB014155 2022-09-06T23:20:03Z International audience We investigate lithosphere necking using two-dimensional thermo-mechanical numerical simulations without strain softening or weakening mechanisms. The models have an initial small sinusoidal perturbation of the Moho depth, whose wavelength corresponds to the model width. Applied boundary conditions (constant extension velocity or bulk extension rate) and initial model width significantly impact the necking dynamics. For constant bulk extension rates, wider models generate more intense necking with locally higher strain rates, whereas for constant velocity extension, models evolution is similar independent on their initial width. However, the width of the final necking zones ranges consistentlybetween 45 and 105 km, independent on the type of applied boundary conditions and the initial Moho wavelength. The modeled widths are similar to along dip necking zones widths of natural rifted margins that formed during a single, unidirectional, and relatively continuous extensional event(e.g., Iberia-Newfoundland margins, Porcupine Basin, Gulf of Aden). When the crust is mechanically decoupled from the mantle by a weak ductile lower crust, models exhibit three characteristic stages: (1) distributed thinning and extension associated with progressive subsidence; (2) upper mantle necking compensated by flow of the weak lower crust, which hampers both crustal thinning and subsidence at the rift center; and (3) crustal necking associated with fast subsidence after the mantle has necked. Decoupled models display regions of relatively thick crust on one or both sides of the rift center, comparable to the Galicia, Rockall, Hatton, and Porcupine Banks along the North Atlantic rifted margins. Article in Journal/Newspaper Newfoundland North Atlantic Université de Nantes: HAL-UNIV-NANTES Journal of Geophysical Research: Solid Earth 123 6 5279 5299 |
institution |
Open Polar |
collection |
Université de Nantes: HAL-UNIV-NANTES |
op_collection_id |
ftunivnantes |
language |
English |
topic |
Rift Necking Numerical modeling [SDU.STU]Sciences of the Universe [physics]/Earth Sciences [SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics |
spellingShingle |
Rift Necking Numerical modeling [SDU.STU]Sciences of the Universe [physics]/Earth Sciences [SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics Chenin, Pauline Schmalholz, Stefan Markus Manatschal, Gianreto Karner, Garry Necking of the Lithosphere: A Reappraisal of Basic Concepts With Thermo-Mechanical Numerical Modeling |
topic_facet |
Rift Necking Numerical modeling [SDU.STU]Sciences of the Universe [physics]/Earth Sciences [SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics |
description |
International audience We investigate lithosphere necking using two-dimensional thermo-mechanical numerical simulations without strain softening or weakening mechanisms. The models have an initial small sinusoidal perturbation of the Moho depth, whose wavelength corresponds to the model width. Applied boundary conditions (constant extension velocity or bulk extension rate) and initial model width significantly impact the necking dynamics. For constant bulk extension rates, wider models generate more intense necking with locally higher strain rates, whereas for constant velocity extension, models evolution is similar independent on their initial width. However, the width of the final necking zones ranges consistentlybetween 45 and 105 km, independent on the type of applied boundary conditions and the initial Moho wavelength. The modeled widths are similar to along dip necking zones widths of natural rifted margins that formed during a single, unidirectional, and relatively continuous extensional event(e.g., Iberia-Newfoundland margins, Porcupine Basin, Gulf of Aden). When the crust is mechanically decoupled from the mantle by a weak ductile lower crust, models exhibit three characteristic stages: (1) distributed thinning and extension associated with progressive subsidence; (2) upper mantle necking compensated by flow of the weak lower crust, which hampers both crustal thinning and subsidence at the rift center; and (3) crustal necking associated with fast subsidence after the mantle has necked. Decoupled models display regions of relatively thick crust on one or both sides of the rift center, comparable to the Galicia, Rockall, Hatton, and Porcupine Banks along the North Atlantic rifted margins. |
author2 |
Institut de physique du globe de Strasbourg (IPGS) Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) Université de Strasbourg (UNISTRA) Université de Lausanne = University of Lausanne (UNIL) Ecole et Observatoire des Sciences de la Terre (EOST) Now at ExxonMobil Exploration Company |
format |
Article in Journal/Newspaper |
author |
Chenin, Pauline Schmalholz, Stefan Markus Manatschal, Gianreto Karner, Garry |
author_facet |
Chenin, Pauline Schmalholz, Stefan Markus Manatschal, Gianreto Karner, Garry |
author_sort |
Chenin, Pauline |
title |
Necking of the Lithosphere: A Reappraisal of Basic Concepts With Thermo-Mechanical Numerical Modeling |
title_short |
Necking of the Lithosphere: A Reappraisal of Basic Concepts With Thermo-Mechanical Numerical Modeling |
title_full |
Necking of the Lithosphere: A Reappraisal of Basic Concepts With Thermo-Mechanical Numerical Modeling |
title_fullStr |
Necking of the Lithosphere: A Reappraisal of Basic Concepts With Thermo-Mechanical Numerical Modeling |
title_full_unstemmed |
Necking of the Lithosphere: A Reappraisal of Basic Concepts With Thermo-Mechanical Numerical Modeling |
title_sort |
necking of the lithosphere: a reappraisal of basic concepts with thermo-mechanical numerical modeling |
publisher |
HAL CCSD |
publishDate |
2018 |
url |
https://hal.archives-ouvertes.fr/hal-01893589 https://hal.archives-ouvertes.fr/hal-01893589/document https://hal.archives-ouvertes.fr/hal-01893589/file/2017JB014155.pdf https://doi.org/10.1029/2017JB014155 |
genre |
Newfoundland North Atlantic |
genre_facet |
Newfoundland North Atlantic |
op_source |
ISSN: 2169-9313 EISSN: 2169-9356 Journal of Geophysical Research : Solid Earth https://hal.archives-ouvertes.fr/hal-01893589 Journal of Geophysical Research : Solid Earth, American Geophysical Union, 2018, 123 (6), pp.5279-5299. ⟨10.1029/2017JB014155⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1029/2017JB014155 hal-01893589 https://hal.archives-ouvertes.fr/hal-01893589 https://hal.archives-ouvertes.fr/hal-01893589/document https://hal.archives-ouvertes.fr/hal-01893589/file/2017JB014155.pdf doi:10.1029/2017JB014155 |
op_rights |
http://hal.archives-ouvertes.fr/licences/copyright/ info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.1029/2017JB014155 |
container_title |
Journal of Geophysical Research: Solid Earth |
container_volume |
123 |
container_issue |
6 |
container_start_page |
5279 |
op_container_end_page |
5299 |
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1766109575782596608 |