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<OAI-PMH schemaLocation=http://www.openarchives.org/OAI/2.0/ http://www.openarchives.org/OAI/2.0/OAI-PMH.xsd> <responseDate>2018-01-15T18:23:32Z</responseDate> <request identifier=oai:HAL:hal-01306664v1 verb=GetRecord metadataPrefix=oai_dc>http://api.archives-ouvertes.fr/oai/hal/</request> <GetRecord> <record> <header> <identifier>oai:HAL:hal-01306664v1</identifier> <datestamp>2018-01-11</datestamp> <setSpec>type:ART</setSpec> <setSpec>subject:sdu</setSpec> <setSpec>collection:CNRS</setSpec> <setSpec>collection:UNIV-AG</setSpec> <setSpec>collection:GM</setSpec> <setSpec>collection:UPMC</setSpec> <setSpec>collection:ISTEP</setSpec> <setSpec>collection:AGROPOLIS</setSpec> <setSpec>collection:INSU</setSpec> <setSpec>collection:ISTEP-PGM2</setSpec> <setSpec>collection:ISTEP-LSD</setSpec> <setSpec>collection:UPMC_POLE_3</setSpec> <setSpec>collection:B3ESTE</setSpec> <setSpec>collection:UNIV-MONTPELLIER</setSpec> </header> <metadata><dc> <publisher>HAL CCSD</publisher> <title lang=en>Strain localization and fluid infiltration in the mantle wedge during subduction initiation: Evidence from the base of the New Caledonia ophiolite</title> <creator>Soret, Mathieu</creator> <creator>Agard, Philippe</creator> <creator>Dubacq, Benoît</creator> <creator>Vitale-Brovarone, A.</creator> <creator>MONIE, Patrick</creator> <creator>CHAUVET, Alain</creator> <creator>Whitechurch, H.</creator> <creator>Villemant, Benoît</creator> <contributor>Institut des Sciences de la Terre de Paris (iSTeP) ; Université Pierre et Marie Curie - Paris 6 (UPMC) - Centre National de la Recherche Scientifique (CNRS)</contributor> <contributor>Géosciences Montpellier ; Université des Antilles et de la Guyane (UAG) - Institut national des sciences de l'Univers (INSU - CNRS) - Université de Montpellier (UM) - Centre National de la Recherche Scientifique (CNRS)</contributor> <contributor>Dynamique de la Lithosphere ; Géosciences Montpellier ; Université des Antilles et de la Guyane (UAG) - Institut national des sciences de l'Univers (INSU - CNRS) - Université de Montpellier (UM) - Centre National de la Recherche Scientifique (CNRS) - Université des Antilles et de la Guyane (UAG) - Institut national des sciences de l'Univers (INSU - CNRS) - Université de Montpellier (UM) - Centre National de la Recherche Scientifique (CNRS)</contributor> <contributor>Geologie des Reservoirs et Ressources ; Géosciences Montpellier ; Université des Antilles et de la Guyane (UAG) - Institut national des sciences de l'Univers (INSU - CNRS) - Université de Montpellier (UM) - Centre National de la Recherche Scientifique (CNRS) - Université des Antilles et de la Guyane (UAG) - Institut national des sciences de l'Univers (INSU - CNRS) - Université de Montpellier (UM) - Centre National de la Recherche Scientifique (CNRS)</contributor> <contributor>Institut de physique du globe de Strasbourg (IPGS) ; Institut national des sciences de l'Univers (INSU - CNRS) - Centre National de la Recherche Scientifique (CNRS)</contributor> <description>International audience</description> <source>ISSN: 0024-4937</source> <source>Lithos</source> <publisher>Elsevier</publisher> <identifier>hal-01306664</identifier> <identifier>https://hal.archives-ouvertes.fr/hal-01306664</identifier> <identifier>https://hal.archives-ouvertes.fr/hal-01306664/document</identifier> <identifier>https://hal.archives-ouvertes.fr/hal-01306664/file/Soret_2016_Strain_localization.pdf</identifier> <source>https://hal.archives-ouvertes.fr/hal-01306664</source> <source>Lithos, Elsevier, 2016, 244, pp.1-19. 〈10.1016/j.lithos.2015.11.022〉</source> <identifier>DOI : 10.1016/j.lithos.2015.11.022</identifier> <relation>info:eu-repo/semantics/altIdentifier/doi/10.1016/j.lithos.2015.11.022</relation> <language>en</language> <subject lang=en>Subduction initiation</subject> <subject lang=en>Supra-subduction zone metasomatism</subject> <subject lang=en>Obducted ophiolite</subject> <subject lang=en>Amphibolite shear bands</subject> <subject>[SDU.STU.GC] Sciences of the Universe [physics]/Earth Sciences/Geochemistry</subject> <type>info:eu-repo/semantics/article</type> <type>Journal articles</type> <description lang=en>Despite decades of petrological and geochemical studies, the nature and setting of obducted ophiolites remain controversial: the influence of supra-subduction zone environments on pre-existing oceanic lithosphere is yet to assess, and the processes leading to subduction/obduction initiation are still poorly constrained. Our study documents successive influx of slab-derived fluids and progressive strain localization within the upper mantle in a supra-subduction environment during the first few My of the subduction history. We focus on strongly sheared mafic amphibolites intruding peridotites near the mantle–crust transition of the New Caledonia obducted ophiolite and ~ 50 to 100 m above the basal thrust contact of the ophiolite. These m- to hm-long and several m-thick shear bands are interpreted as inherited small-scale intrusions of mafic melts, probably dikes or sills, which were derived from a moderately refractory mantle source refertilized by supra-subduction zone fluids. 40Ar/39Ar age constraints on pargasite at ca. 90 Ma suggest that they could be inherited from the former Pacific west-dipping subduction.Secondary deformation of these mafic intrusions is intimately associated to three major stages of fluid infiltration: (1) the first stage of deformation and metasomatism is marked by syn-kinematic growth of Ca-amphibole (at 700–800 °C and 3–5 kbar) with a distinctive supra-subduction zone signature, and controlled later channelization of aqueous fluids. 40Ar/39Ar dating on magnesio-hornblende indicates that this deformation episode occurred at ca. 55 Ma, coincident with east-dipping subduction initiation; (2) the main metasomatic stage, characterized by the development of a phlogopite-rich matrix wrapping peridotites and amphibolite boudins, points to the percolation of alkali-rich aqueous fluids at still high temperature (650–750 °C); (3) the last, low temperature (< 600 °C) metasomatic stage results in the formation of deformed veinlets containing talc, chlorite and serpentine.</description> <date>2016-02-01</date> </dc> </metadata> </record> </GetRecord> </OAI-PMH>