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Mapping the evolving strain field during continental breakup from crustal anisotropy in the Afar Depression
Rifting of the continents leading to plate rupture occurs by a combination of mechanical deformation and magma intrusion, yet the spatial and temporal scales over which these alternate mechanisms localize extensional strain remain controversial. Here we quantify anisotropy of the upper crust across...
Autores principales: | , , , , , , , |
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Formato: | Texto |
Lenguaje: | English |
Publicado: |
Nature Publishing Group
2011
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3104516/ https://www.ncbi.nlm.nih.gov/pubmed/21505441 http://dx.doi.org/10.1038/ncomms1287 |
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author | Keir, Derek Belachew, M. Ebinger, C.J. Kendall, J.-M. Hammond, J.O.S. Stuart, G.W. Ayele, A. Rowland, J.V. |
author_facet | Keir, Derek Belachew, M. Ebinger, C.J. Kendall, J.-M. Hammond, J.O.S. Stuart, G.W. Ayele, A. Rowland, J.V. |
author_sort | Keir, Derek |
collection | PubMed |
description | Rifting of the continents leading to plate rupture occurs by a combination of mechanical deformation and magma intrusion, yet the spatial and temporal scales over which these alternate mechanisms localize extensional strain remain controversial. Here we quantify anisotropy of the upper crust across the volcanically active Afar Triple Junction using shear-wave splitting from local earthquakes to evaluate the distribution and orientation of strain in a region of continental breakup. The pattern of S-wave splitting in Afar is best explained by anisotropy from deformation-related structures, with the dramatic change in splitting parameters into the rift axis from the increased density of dyke-induced faulting combined with a contribution from oriented melt pockets near volcanic centres. The lack of rift-perpendicular anisotropy in the lithosphere, and corroborating geoscientific evidence of extension dominated by dyking, provide strong evidence that magma intrusion achieves the majority of plate opening in this zone of incipient plate rupture. |
format | Text |
id | pubmed-3104516 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2011 |
publisher | Nature Publishing Group |
record_format | MEDLINE/PubMed |
spelling | pubmed-31045162011-06-01 Mapping the evolving strain field during continental breakup from crustal anisotropy in the Afar Depression Keir, Derek Belachew, M. Ebinger, C.J. Kendall, J.-M. Hammond, J.O.S. Stuart, G.W. Ayele, A. Rowland, J.V. Nat Commun Article Rifting of the continents leading to plate rupture occurs by a combination of mechanical deformation and magma intrusion, yet the spatial and temporal scales over which these alternate mechanisms localize extensional strain remain controversial. Here we quantify anisotropy of the upper crust across the volcanically active Afar Triple Junction using shear-wave splitting from local earthquakes to evaluate the distribution and orientation of strain in a region of continental breakup. The pattern of S-wave splitting in Afar is best explained by anisotropy from deformation-related structures, with the dramatic change in splitting parameters into the rift axis from the increased density of dyke-induced faulting combined with a contribution from oriented melt pockets near volcanic centres. The lack of rift-perpendicular anisotropy in the lithosphere, and corroborating geoscientific evidence of extension dominated by dyking, provide strong evidence that magma intrusion achieves the majority of plate opening in this zone of incipient plate rupture. Nature Publishing Group 2011-04 2011-04-19 /pmc/articles/PMC3104516/ /pubmed/21505441 http://dx.doi.org/10.1038/ncomms1287 Text en Copyright © 2011, Nature Publishing Group, a division of Macmillan Publishers Limited. All Rights Reserved. http://creativecommons.org/licenses/by-nc-sa/3.0/ This work is licensed under a Creative Commons Attribution-NonCommercial-Share Alike 3.0 Unported License. To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/ |
spellingShingle | Article Keir, Derek Belachew, M. Ebinger, C.J. Kendall, J.-M. Hammond, J.O.S. Stuart, G.W. Ayele, A. Rowland, J.V. Mapping the evolving strain field during continental breakup from crustal anisotropy in the Afar Depression |
title | Mapping the evolving strain field during continental breakup from crustal anisotropy in the Afar Depression |
title_full | Mapping the evolving strain field during continental breakup from crustal anisotropy in the Afar Depression |
title_fullStr | Mapping the evolving strain field during continental breakup from crustal anisotropy in the Afar Depression |
title_full_unstemmed | Mapping the evolving strain field during continental breakup from crustal anisotropy in the Afar Depression |
title_short | Mapping the evolving strain field during continental breakup from crustal anisotropy in the Afar Depression |
title_sort | mapping the evolving strain field during continental breakup from crustal anisotropy in the afar depression |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3104516/ https://www.ncbi.nlm.nih.gov/pubmed/21505441 http://dx.doi.org/10.1038/ncomms1287 |
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