Seismic evidence of exhumed mantle rock basement at the Gorringe Bank and the adjacent Horseshoe and Tagus abyssal plains (SW Iberia)
International audience The Gorringe Bank is a gigantic seamount that separates the Horseshoe and Tagus abyssal plains offshore SW Iberia, in a zone that hosts the convergent boundary between the Africa and Eurasia plates. Although the region has been the focus of numerous investigations since the ea...
Published in: | Earth and Planetary Science Letters |
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Main Authors: | , , , , , , , , , |
Other Authors: | , , , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
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HAL CCSD
2013
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Online Access: | https://insu.hal.science/insu-00798004 https://doi.org/10.1016/j.epsl.2013.01.021 |
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ftinsu:oai:HAL:insu-00798004v1 |
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Open Polar |
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Institut national des sciences de l'Univers: HAL-INSU |
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language |
English |
topic |
mantle exhumation North Atlantic margin wide-Angle seismics travel-time tomography gravity modelling [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 |
mantle exhumation North Atlantic margin wide-Angle seismics travel-time tomography gravity modelling [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 Sallarès, Valentí Martinez-Loriente, Sara Prada, Manuel Gracia, Eulalia Ranero, César Gutscher, Marc-André, M-A Bartolome, Rafael Gailler, A. Dañobeitia, Juan José Zitellini, Nevio Seismic evidence of exhumed mantle rock basement at the Gorringe Bank and the adjacent Horseshoe and Tagus abyssal plains (SW Iberia) |
topic_facet |
mantle exhumation North Atlantic margin wide-Angle seismics travel-time tomography gravity modelling [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 Gorringe Bank is a gigantic seamount that separates the Horseshoe and Tagus abyssal plains offshore SW Iberia, in a zone that hosts the convergent boundary between the Africa and Eurasia plates. Although the region has been the focus of numerous investigations since the early 1970s, the lack of appropriate geophysical data makes the nature of the basement, and thus the origin of the structures, still debated. In this work, we present combined P-wave seismic velocity and gravity models along a transect that crosses the Gorringe Bank from the Tagus to the Horseshoe abyssal plains. The P-wave velocity structure of the basement is similar in the Tagus and Horseshoe plains. It shows a 2.5-3.0 km-thick top layer with a velocity gradient twice stronger than oceanic Layer 2 and an abrupt change to an underlying layer with a five-fold weaker gradient. Velocity and density is lower beneath the Gorringe Bank probably due to enhanced fracturing, that have led to rock disaggregation in the sediment-starved northern flank. In contrast to previous velocity models of this region, there is no evidence of a sharp crust-mantle boundary in any of the record sections. The modelling results indicate that the sediment overlays directly serpentinite rock, exhumed from the mantle with a degree of serpentinization decreasing from a maximum of 70-80% under the top of Gorringe Bank to less than 5% at a depth of ∼20 km. We propose that the three domains were originally part of a single serpentine rock band, of nature and possibly origin similar to the Iberia Abyssal Plain ocean-continent transition, which was probably generated during the earliest phase of the North Atlantic opening that followed continental crust breakup (Early Cretaceous). During the Miocene, the NW-SE trending Eurasia-Africa convergence resulted in thrusting of the southeastern segment of the exhumed serpentinite band over the northwestern one, forming the Gorringe Bank. The local deformation associated to plate convergence and uplift could ... |
author2 |
Unitat de Tecnologia Marina (UTM) Centre Mediterrani d'Investigacions Marines I ambientals Institució Catalana de Recerca i Estudis Avançats (ICREA) 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) DAM Île-de-France (DAM/DIF) Direction des Applications Militaires (DAM) Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA) Istituto di Scienze Marine Bologna (ISMAR) Istituto di Science Marine (ISMAR ) National Research Council of Italy European Project: 34220,NEAREST |
format |
Article in Journal/Newspaper |
author |
Sallarès, Valentí Martinez-Loriente, Sara Prada, Manuel Gracia, Eulalia Ranero, César Gutscher, Marc-André, M-A Bartolome, Rafael Gailler, A. Dañobeitia, Juan José Zitellini, Nevio |
author_facet |
Sallarès, Valentí Martinez-Loriente, Sara Prada, Manuel Gracia, Eulalia Ranero, César Gutscher, Marc-André, M-A Bartolome, Rafael Gailler, A. Dañobeitia, Juan José Zitellini, Nevio |
author_sort |
Sallarès, Valentí |
title |
Seismic evidence of exhumed mantle rock basement at the Gorringe Bank and the adjacent Horseshoe and Tagus abyssal plains (SW Iberia) |
title_short |
Seismic evidence of exhumed mantle rock basement at the Gorringe Bank and the adjacent Horseshoe and Tagus abyssal plains (SW Iberia) |
title_full |
Seismic evidence of exhumed mantle rock basement at the Gorringe Bank and the adjacent Horseshoe and Tagus abyssal plains (SW Iberia) |
title_fullStr |
Seismic evidence of exhumed mantle rock basement at the Gorringe Bank and the adjacent Horseshoe and Tagus abyssal plains (SW Iberia) |
title_full_unstemmed |
Seismic evidence of exhumed mantle rock basement at the Gorringe Bank and the adjacent Horseshoe and Tagus abyssal plains (SW Iberia) |
title_sort |
seismic evidence of exhumed mantle rock basement at the gorringe bank and the adjacent horseshoe and tagus abyssal plains (sw iberia) |
publisher |
HAL CCSD |
publishDate |
2013 |
url |
https://insu.hal.science/insu-00798004 https://doi.org/10.1016/j.epsl.2013.01.021 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
ISSN: 0012-821X Earth and Planetary Science Letters https://insu.hal.science/insu-00798004 Earth and Planetary Science Letters, 2013, 365, pp.120-131. ⟨10.1016/j.epsl.2013.01.021⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1016/j.epsl.2013.01.021 info:eu-repo/grantAgreement//34220/EU/INTEGRATED OBSERVATIONS FROM NEAR SHORE SOURCES OF TSUNAMIS: TOWARDS AN EARLY WARNING SYSTEM/NEAREST insu-00798004 https://insu.hal.science/insu-00798004 doi:10.1016/j.epsl.2013.01.021 |
op_doi |
https://doi.org/10.1016/j.epsl.2013.01.021 |
container_title |
Earth and Planetary Science Letters |
container_volume |
365 |
container_start_page |
120 |
op_container_end_page |
131 |
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1797588444216557568 |
spelling |
ftinsu:oai:HAL:insu-00798004v1 2024-04-28T08:30:39+00:00 Seismic evidence of exhumed mantle rock basement at the Gorringe Bank and the adjacent Horseshoe and Tagus abyssal plains (SW Iberia) Sallarès, Valentí Martinez-Loriente, Sara Prada, Manuel Gracia, Eulalia Ranero, César Gutscher, Marc-André, M-A Bartolome, Rafael Gailler, A. Dañobeitia, Juan José Zitellini, Nevio Unitat de Tecnologia Marina (UTM) Centre Mediterrani d'Investigacions Marines I ambientals Institució Catalana de Recerca i Estudis Avançats (ICREA) 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) DAM Île-de-France (DAM/DIF) Direction des Applications Militaires (DAM) Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA) Istituto di Scienze Marine Bologna (ISMAR) Istituto di Science Marine (ISMAR ) National Research Council of Italy European Project: 34220,NEAREST 2013-03-01 https://insu.hal.science/insu-00798004 https://doi.org/10.1016/j.epsl.2013.01.021 en eng HAL CCSD Elsevier info:eu-repo/semantics/altIdentifier/doi/10.1016/j.epsl.2013.01.021 info:eu-repo/grantAgreement//34220/EU/INTEGRATED OBSERVATIONS FROM NEAR SHORE SOURCES OF TSUNAMIS: TOWARDS AN EARLY WARNING SYSTEM/NEAREST insu-00798004 https://insu.hal.science/insu-00798004 doi:10.1016/j.epsl.2013.01.021 ISSN: 0012-821X Earth and Planetary Science Letters https://insu.hal.science/insu-00798004 Earth and Planetary Science Letters, 2013, 365, pp.120-131. ⟨10.1016/j.epsl.2013.01.021⟩ mantle exhumation North Atlantic margin wide-Angle seismics travel-time tomography gravity modelling [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 2013 ftinsu https://doi.org/10.1016/j.epsl.2013.01.021 2024-04-05T00:21:12Z International audience The Gorringe Bank is a gigantic seamount that separates the Horseshoe and Tagus abyssal plains offshore SW Iberia, in a zone that hosts the convergent boundary between the Africa and Eurasia plates. Although the region has been the focus of numerous investigations since the early 1970s, the lack of appropriate geophysical data makes the nature of the basement, and thus the origin of the structures, still debated. In this work, we present combined P-wave seismic velocity and gravity models along a transect that crosses the Gorringe Bank from the Tagus to the Horseshoe abyssal plains. The P-wave velocity structure of the basement is similar in the Tagus and Horseshoe plains. It shows a 2.5-3.0 km-thick top layer with a velocity gradient twice stronger than oceanic Layer 2 and an abrupt change to an underlying layer with a five-fold weaker gradient. Velocity and density is lower beneath the Gorringe Bank probably due to enhanced fracturing, that have led to rock disaggregation in the sediment-starved northern flank. In contrast to previous velocity models of this region, there is no evidence of a sharp crust-mantle boundary in any of the record sections. The modelling results indicate that the sediment overlays directly serpentinite rock, exhumed from the mantle with a degree of serpentinization decreasing from a maximum of 70-80% under the top of Gorringe Bank to less than 5% at a depth of ∼20 km. We propose that the three domains were originally part of a single serpentine rock band, of nature and possibly origin similar to the Iberia Abyssal Plain ocean-continent transition, which was probably generated during the earliest phase of the North Atlantic opening that followed continental crust breakup (Early Cretaceous). During the Miocene, the NW-SE trending Eurasia-Africa convergence resulted in thrusting of the southeastern segment of the exhumed serpentinite band over the northwestern one, forming the Gorringe Bank. The local deformation associated to plate convergence and uplift could ... Article in Journal/Newspaper North Atlantic Institut national des sciences de l'Univers: HAL-INSU Earth and Planetary Science Letters 365 120 131 |