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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>2018-01-15T18:23:47Z</responseDate> <request identifier=oai:HAL:insu-01309394v1 verb=GetRecord metadataPrefix=oai_dc>http://api.archives-ouvertes.fr/oai/hal/</request> <GetRecord> <record> <header> <identifier>oai:HAL:insu-01309394v1</identifier> <datestamp>2018-01-11</datestamp> <setSpec>type:POSTER</setSpec> <setSpec>subject:sdu</setSpec> <setSpec>collection:INSU</setSpec> <setSpec>collection:CNRS</setSpec> <setSpec>collection:UNIV-AG</setSpec> <setSpec>collection:OSUG</setSpec> <setSpec>collection:GR</setSpec> <setSpec>collection:GM</setSpec> <setSpec>collection:UPMC</setSpec> <setSpec>collection:ISTEP</setSpec> <setSpec>collection:UNIV-RENNES1</setSpec> <setSpec>collection:GR7</setSpec> <setSpec>collection:OSUR</setSpec> <setSpec>collection:UNIV-GRENOBLE1</setSpec> <setSpec>collection:ISTERRE</setSpec> <setSpec>collection:AGROPOLIS</setSpec> <setSpec>collection:UNIV-SAVOIE</setSpec> <setSpec>collection:IFSTTAR</setSpec> <setSpec>collection:UGA</setSpec> <setSpec>collection:UR1-SDLM</setSpec> <setSpec>collection:UR1-SDLMJONCH</setSpec> <setSpec>collection:UR1-HAL</setSpec> <setSpec>collection:GR-3T</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>Metamorphic sole formation and early plate interface rheology: Insights from Griggs apparatus experiments</title> <creator>Soret, Mathieu</creator> <creator>Agard, Philippe</creator> <creator>Dubacq, Benoît</creator> <creator>Hirth, Greg</creator> <creator>Yamato, Philippe</creator> <creator>Ildefonse, Benoit</creator> <creator>Prigent, Cécile</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>Department of geological sciences ; Brown University</contributor> <contributor>Géosciences Rennes (GR) ; Université de Rennes 1 (UR1) - Institut national des sciences de l'Univers (INSU - CNRS) - Observatoire des Sciences de l'Univers de Rennes (OSUR) - 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>Institut des Sciences de la Terre (ISTerre) ; Université Joseph Fourier - Grenoble 1 (UJF) - Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR) - Institut national des sciences de l'Univers (INSU - CNRS) - Institut de recherche pour le développement [IRD] : UR219 - PRES Université de Grenoble - Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry]) - Centre National de la Recherche Scientifique (CNRS)</contributor> <description>International audience</description> <source>European Geosciences Union General Assembly 2016</source> <coverage>Vienne, Austria</coverage> <contributor>European Geosciences Union</contributor> <identifier>insu-01309394</identifier> <identifier>https://hal-insu.archives-ouvertes.fr/insu-01309394</identifier> <source>https://hal-insu.archives-ouvertes.fr/insu-01309394</source> <source>European Geosciences Union General Assembly 2016, Apr 2016, Vienne, Austria. Geophysical Research Abstracts, 18, pp.EGU2016-15599, 2016</source> <language>en</language> <subject>[SDU.STU.TE] Sciences of the Universe [physics]/Earth Sciences/Tectonics</subject> <type>info:eu-repo/semantics/conferenceObject</type> <type>Poster communications</type> <description lang=en>Metamorphic soles correspond to m to 500 m thick highly strained metamorphic rock units found beneath myloniticbanded peridotites at the base of large-scale ophiolites, as exemplified in Oman. Metamorphic soles aremainly composed of metabasalts deriving from the downgoing oceanic lithosphere and metamorphosed up togranulite-facies conditions by heat transfer from the mantle wedge. Pressure–temperature peak conditions areusually estimated at 1.00.2 GPa and 800100ºC. The absence of HP–LT metamorphism overprint implies thatmetamorphic soles have been formed and exhumed during subduction infancy. In this view, metamorphic soleswere strongly deformed during their accretion to the mantle wedge (corresponding, now, to the base of the ophiolite).Therefore, metamorphic soles and banded peridotites are direct witnesses of the dynamics of early subductionzones, in terms of thermal structure, fluid migration and rheology evolution across the nascent slab interface.Based on fieldwork and EBSD analyses, we present a detailed (micro–) structural study performed on samplescoming from the Sumeini window, the better-preserved cross-section of the metamorphic sole of Oman. Largedifferences are found in the deformation (CPO, grain size, aspect ratio) of clinopyroxene, amphibole and plagioclase,related to mineralogical changes linked with the distance to the peridotite contact (e.g., hardening due to theappearance of garnet and clinopyroxene).To model the incipient slab interface in laboratory, we carried out 5 hydrostatic annealing and simple-shear experimentson Griggs solid-medium apparatus. Deformation experiments were conducted at axial strain rates of 10-6s-1. Fine-grained amphibolite was synthetized by adding 1 wt.% water to a (Mid-Ocean Ridge) basalt powder asa proxy for the metamorphic sole (amphibole + plagioclase + clinopyroxene garnet assemblage). To synthetizegarnet, 2 experiments were carried out in hydrostatic conditions and with deformation at 800C with confiningpressure of 2 GPa. Another simple-shear experiment has been carried out at 800C and 1 GPa with fined-grainednatural garnet. With the aim of mimicking the early slab interface (between the metamorphic sole and bandedperidotites at the base of the ophiolite), 2 simple-shear deformation experiments with 2 layers have been carriedout at 800C and confining pressure of 1 GPa. The bottom layer was made of hydrated basalt powder and the toplayer was made of olivine.Fined-grained garnet-free amphibolite is significantly weaker than dunite but the appearance of harder mineralsin the amphibolite (garnet and clinopyroxene) has major implications on its rheological evolution. These resultsallow liking field observations of strain localization at the interface to the metamorphic sole formation</description> <date>2016-04-12</date> </dc> </metadata> </record> </GetRecord> </OAI-PMH>