Seismic evidence for the presence of Jurassic oceanic crust in the central Gulf of Cadiz (SW Iberian margin)

12 pages, 9 figures

Detalhes bibliográficos
Autores: Sallarès, Valentí, Gailler, Audrey, Gutscher, Marc-André, Graindorge, David, Bartolomé, Rafael, Gràcia, Eulàlia, Díaz, Jordi, Dañobeitia, Juan José, Zitellini, Nevio
Formato: artículo
Fecha de publicación:2011
País:España
Recursos:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/56369
Acesso em linha:http://hdl.handle.net/10261/56369
Access Level:acceso abierto
Palavra-chave:SW Iberian margin
Wide-angle seismics
Refraction and reflection travel-time tomography
Uncertainty analysis
Jurassic oceanic crust
Geodynamic evolution
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spelling Seismic evidence for the presence of Jurassic oceanic crust in the central Gulf of Cadiz (SW Iberian margin)Sallarès, ValentíGailler, AudreyGutscher, Marc-AndréGraindorge, DavidBartolomé, RafaelGràcia, EulàliaDíaz, JordiDañobeitia, Juan JoséZitellini, NevioSW Iberian marginWide-angle seismicsRefraction and reflection travel-time tomographyUncertainty analysisJurassic oceanic crustGeodynamic evolution12 pages, 9 figuresWe investigate the crustal structure of the SW Iberian margin along a 340 km-long refraction and wide-angle reflection seismic profile crossing from the central Gulf of Cadiz to the Variscan continental margin in the Algarve, Southern Portugal. The seismic velocity and crustal geometry model obtained by joint refraction and reflection travel-time inversion reveal three distinct crustal domains: the 28–30 km-thick Variscan crust in the north, a 60 km-wide transition zone offshore, where the crust abruptly thins ~ 20 km, and finally a ~ 7 km-thick and ~ 150 km-wide crustal section that appears to be oceanic in nature. The oceanic crust is overlain by a 1–3 km-thick section of Mesozoic to Eocene sediments, with an additional 3–4 km of low-velocity, unconsolidated sediments on top belonging to the Miocene age, Gulf of Cadiz imbricated wedge. The sharp transition between continental and oceanic crust is best explained by an initial rifting setting as a transform margin during the Early Jurassic that followed the continental break-up in the Central Atlantic. The narrow oceanic basin would have formed during an oblique rifting and seafloor spreading episode between Iberia and Africa that started shortly thereafter (Bajocian) and lasted up to the initiation of oceanic spreading in the North Atlantic at the Tithonian (late Jurassic-earliest Cretaceous). The velocity model displays four wide, prominent, south-dipping low-velocity anomalies, which seem to be related with the presence of crustal-scale faults previously identified in the area, some of which could well be extensional faults generated during this rifting episode. We propose that this oceanic plate segment is the last remnant of an oceanic corridor that once connected the Alpine-Tethys with the Atlantic ocean, so it is, in turn, one of the oldest oceanic crustal fragments currently preserved on Earth. The presence of oceanic crust in the central Gulf of Cadiz is consistent with geodynamic models suggesting the existence of a narrow, westward retreating oceanic slab beneath the Gibraltar arc-Alboran basin systemThe NEAREST project has been funded by the EU Programme “Integrating and Strengthening the European Research Area” of FP6, Sub-Priority 1.1.6.3, “Global Change and Ecosystems”, contract no. 037110, and the NEARESTSEIS survey was funded by the Complementary Action # CGL2006-27098-E/BTE of the Spanish MICINN. Additional funds were obtained from the MICINN projects MEDOC (CTM2007-66179-C02-02/MAR) and SHAKE (CGL2011-30005-C02-02). We also acknowledge funding from MICINN through the Ramon y Cajal program (R. Bartolomé). We finally acknowledge the collaboration of our research partners at Grup de Recerca de la Generalitat de Catalunya Barcelona Centre of Subsurface Imaging (B-CSI) ref. 2009 SGR 146 and funding support from Repsol-YPFPeer reviewedElsevier2011info:eu-repo/semantics/articlehttp://purl.org/coar/resource_type/c_6501http://hdl.handle.net/10261/56369reponame:DIGITAL.CSIC. Repositorio Institucional del CSICinstname:Consejo Superior de Investigaciones Científicas (CSIC)Ingléshttps://doi.org/10.1016/j.epsl.2011.09.003info:eu-repo/semantics/openAccessoai:digital.csic.es:10261/563692026-05-22T06:33:51Z
dc.title.none.fl_str_mv Seismic evidence for the presence of Jurassic oceanic crust in the central Gulf of Cadiz (SW Iberian margin)
title Seismic evidence for the presence of Jurassic oceanic crust in the central Gulf of Cadiz (SW Iberian margin)
spellingShingle Seismic evidence for the presence of Jurassic oceanic crust in the central Gulf of Cadiz (SW Iberian margin)
Sallarès, Valentí
SW Iberian margin
Wide-angle seismics
Refraction and reflection travel-time tomography
Uncertainty analysis
Jurassic oceanic crust
Geodynamic evolution
title_short Seismic evidence for the presence of Jurassic oceanic crust in the central Gulf of Cadiz (SW Iberian margin)
title_full Seismic evidence for the presence of Jurassic oceanic crust in the central Gulf of Cadiz (SW Iberian margin)
title_fullStr Seismic evidence for the presence of Jurassic oceanic crust in the central Gulf of Cadiz (SW Iberian margin)
title_full_unstemmed Seismic evidence for the presence of Jurassic oceanic crust in the central Gulf of Cadiz (SW Iberian margin)
title_sort Seismic evidence for the presence of Jurassic oceanic crust in the central Gulf of Cadiz (SW Iberian margin)
dc.creator.none.fl_str_mv Sallarès, Valentí
Gailler, Audrey
Gutscher, Marc-André
Graindorge, David
Bartolomé, Rafael
Gràcia, Eulàlia
Díaz, Jordi
Dañobeitia, Juan José
Zitellini, Nevio
author Sallarès, Valentí
author_facet Sallarès, Valentí
Gailler, Audrey
Gutscher, Marc-André
Graindorge, David
Bartolomé, Rafael
Gràcia, Eulàlia
Díaz, Jordi
Dañobeitia, Juan José
Zitellini, Nevio
author_role author
author2 Gailler, Audrey
Gutscher, Marc-André
Graindorge, David
Bartolomé, Rafael
Gràcia, Eulàlia
Díaz, Jordi
Dañobeitia, Juan José
Zitellini, Nevio
author2_role author
author
author
author
author
author
author
author
dc.subject.none.fl_str_mv SW Iberian margin
Wide-angle seismics
Refraction and reflection travel-time tomography
Uncertainty analysis
Jurassic oceanic crust
Geodynamic evolution
topic SW Iberian margin
Wide-angle seismics
Refraction and reflection travel-time tomography
Uncertainty analysis
Jurassic oceanic crust
Geodynamic evolution
description 12 pages, 9 figures
publishDate 2011
dc.date.none.fl_str_mv 2011
dc.type.none.fl_str_mv info:eu-repo/semantics/article
http://purl.org/coar/resource_type/c_6501
format article
dc.identifier.none.fl_str_mv http://hdl.handle.net/10261/56369
url http://hdl.handle.net/10261/56369
dc.language.none.fl_str_mv Inglés
language_invalid_str_mv Inglés
dc.relation.none.fl_str_mv https://doi.org/10.1016/j.epsl.2011.09.003
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.publisher.none.fl_str_mv Elsevier
publisher.none.fl_str_mv Elsevier
dc.source.none.fl_str_mv reponame:DIGITAL.CSIC. Repositorio Institucional del CSIC
instname:Consejo Superior de Investigaciones Científicas (CSIC)
instname_str Consejo Superior de Investigaciones Científicas (CSIC)
reponame_str DIGITAL.CSIC. Repositorio Institucional del CSIC
collection DIGITAL.CSIC. Repositorio Institucional del CSIC
repository.name.fl_str_mv
repository.mail.fl_str_mv
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score 15.812429

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