Crustal structure of a young margin pair: New results across the Liguro-Provencal Basin from wide-angle seismic tomography

Autor: Gailler, A., Klingelhoefer, F., Olivet, J.-L., Aslanian, D., Afilhado, A., Bache, François, Beslier, M.-O., Cosquer, E., Deschamps, Anne, Droz, Laurence, Gorini, Christian, Moulin, M., Nouzé, H., Oudet, J., Pascucci, V., Perrot, Julie, Rabineau, Marina, Réhault, J.-P., Allano, L., Begot, Jacques, Crozon, J., Fernagu, P., Labahn, E., Pelleau, P., Théreau, E.
Přispěvatelé: Institut Français de Recherche pour l'Exploitation de la Mer - Brest (IFREMER Centre de Bretagne), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Géoazur (GEOAZUR 6526), Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), 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), Unité de recherche Géosciences Marines (Ifremer) (GM), Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)
Jazyk: angličtina
Rok vydání: 2009
Předmět:
010504 meteorology & atmospheric sciences
[SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph]
[SDE.MCG]Environmental Sciences/Global Changes
Inversion (geology)
[SDU.STU]Sciences of the Universe [physics]/Earth Sciences
[PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph]
010502 geochemistry & geophysics
01 natural sciences
Geochemistry and Petrology
Lithosphere
Oceanic crust
NW-Mediterranean Basin
Earth and Planetary Sciences (miscellaneous)
14. Life underwater
Petrology
0105 earth and related environmental sciences
conjugate margins
Continental crust
Crust
Western Sardinia
travel-time tomography
wide-angle seismic
crustal structure
Detachment fault
Tectonics
Geophysics
Space and Planetary Science
Seismic tomography
Gulf of Lions
Geology
Seismology
Zdroj: Earth and Planetary Science Letters
Earth and Planetary Science Letters, Elsevier, 2009, 286 (1-2), pp.333-345. ⟨10.1016/j.epsl.2009.07.001⟩
Earth and Planetary Science Letters, 2009, 286 (1-2), pp.333-345. ⟨10.1016/j.epsl.2009.07.001⟩
ISSN: 0012-821X
DOI: 10.1016/j.epsl.2009.07.001⟩
Popis: International audience; Tomographic inversion of two wide-angle seismic profiles acquired during the Sardinia cruise (2006) on the conjugate Gulf of Lions-West Sardinia margins pair offers insight into the deep structure of this young basin. It is the first combined conjugate margins study in this area based on deep seismic data. Modelling of the two conjugate profiles reveals that the conjugate margins are symmetric in term of crustal velocity structure, with a partitioning in three similar regions: (1) a zone of low crustal vertical velocity gradients and a crustal thickness of 18 to 10 km, interpreted to be thinned continental crust, (2) a transitional zone characterised by high lower crustal velocities, non-typical of continental or normal oceanic crust, and (3) a 4- to 5-km-thick crust showing vertical velocity gradients and relative velocity ranges typical of oceanic crust. This latter region is interpreted to be a thin oceanic crust resulting from a tectonic heritage and the possible influence of a cool slab back-arc basin. Although the three regions are found on both sides of the margin, they are asymmetric in terms of the width of these domains, wide and smooth along the Gulf of Lions margin, and narrow and abrupt along its conjugate Sardinia side. The width of Region 2 is larger on the Gulf of Lions side (~ 90 km) than on the Sardinia side (~ 40 km). Crustal thickness in Region 3 is about 1 km thinner on the Sardinia side than on its conjugate. In Region 1 the crustal thickness is lower on the Sardinia side at a given distance from the shelf break. The differences in width of Region 2 and in crustal thickness might be due to the origin as a back-arc basin of the NW-Mediterranean basin, with the final breakup located closer to the Western Sardinia margin, also probably linked to the complex tectonic history of the region. Our results do not support a simple shear mechanism of the opening of the basin along a lithospheric detachment fault.
Databáze: OpenAIRE
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