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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>2018-01-15T18:20:01Z</responseDate> <request identifier=oai:HAL:hal-01412663v1 verb=GetRecord metadataPrefix=oai_dc>http://api.archives-ouvertes.fr/oai/hal/</request> <GetRecord> <record> <header> <identifier>oai:HAL:hal-01412663v1</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:LMV</setSpec> <setSpec>collection:AGROPOLIS</setSpec> <setSpec>collection:UNIV-BPCLERMONT</setSpec> <setSpec>collection:UNIV-ST-ETIENNE</setSpec> <setSpec>collection:GIP-BE</setSpec> <setSpec>collection:INSU</setSpec> <setSpec>collection:PRES_CLERMONT</setSpec> <setSpec>collection:B3ESTE</setSpec> <setSpec>collection:UNIV-MONTPELLIER</setSpec> <setSpec>collection:OPGC</setSpec> </header> <metadata><dc> <publisher>HAL CCSD</publisher> <title lang=en>Diffusivity of hydrogen in iron-bearing olivine at 3 GPa</title> <creator>DEMOUCHY, Sylvie</creator> <creator>THORAVAL, Catherine</creator> <creator>Bolfan-casanova, Nathalie</creator> <creator>Manthilake, Geeth</creator> <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>Manteau et Interfaces ; 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>Laboratoire Magmas et Volcans (LMV) ; Université Blaise Pascal - Clermont-Ferrand 2 (UBP) - Institut national des sciences de l'Univers (INSU - CNRS) - Université Jean Monnet [Saint-Étienne] (UJM) - Centre National de la Recherche Scientifique (CNRS)</contributor> <description>International audience</description> <source>ISSN: 0031-9201</source> <source>EISSN: 0031-9201</source> <source>Physics of the Earth and Planetary Interiors</source> <publisher>Elsevier</publisher> <identifier>hal-01412663</identifier> <identifier>https://hal.archives-ouvertes.fr/hal-01412663</identifier> <source>https://hal.archives-ouvertes.fr/hal-01412663</source> <source>Physics of the Earth and Planetary Interiors, Elsevier, 2016, 260, pp.1-13. 〈10.1016/j.pepi.2016.08.005〉</source> <identifier>DOI : 10.1016/j.pepi.2016.08.005</identifier> <relation>info:eu-repo/semantics/altIdentifier/doi/10.1016/j.pepi.2016.08.005</relation> <language>en</language> <subject lang=en>FTIR spectroscopy</subject> <subject lang=en>Olivine</subject> <subject lang=en>Hydrogen</subject> <subject lang=en>Ionic diffusion</subject> <subject lang=en>Point defects</subject> <subject>[SDU.STU.PE] Sciences of the Universe [physics]/Earth Sciences/Petrography</subject> <type>info:eu-repo/semantics/article</type> <type>Journal articles</type> <description lang=en>The kinetics of hydrogenation of dry iron-bearing olivine single crystals was determined by performing hydration experiments under hydrothermal conditions at high pressure. The experiments were performed in a multi-anvil press at 3 GPa, for a temperature range between 900 and 1200 °C and for various durations. The oxygen fugacity was buffered along Ni-NiO joint. Polarized Fourier transform infrared spectroscopy and recent empirical calibration were used to quantify the hydroxyl distributions in the samples along crystallographic axes after the experiments. The chemical diffusion coefficients are similar (barely slower) than in olivine hydrated at lower pressure (0.2 and 0.3 GPa) for the same diffusion mechanism. Under the given experimental conditions, the anisotropy of diffusion is the same as for proton-vacancy mechanism, with diffusion along the [0 0 1] axis faster than along the [1 0 0]. However, the anisotropy at 3 GPa is weaker compared to measurements at lower pressures and the analysis of concentration profiles using 3D models shows that an isotropic solution could also be relevant. Fits of the diffusion data to an Arrhenius law yield activation energies for the slightly faster [0 0 1] axis of the crystallographic axes around 198 ± 5 kJ mol−1, a value only slightly lower than the results from previous experimental studies for natural iron-bearing olivine hydrogenated at lower confining pressure. At 3 GPa, hydrogenation can be well approximated by a single mechanism controlled by coupled diffusion of protons and octahedral vacancies (di- and tri-valent ions). The diffusion rates are fast enough to alter hydrogen concentration within olivine in xenoliths ascending from the mantle or experiencing hydrogen-rich metasomatism events, but too slow to permit complete homogenization of hydrogen in olivine-rich rocks at kilometer scale in less than one My.</description> <date>2016-11</date> </dc> </metadata> </record> </GetRecord> </OAI-PMH>