%0 Conference Proceedings %T The role of volatiles (H2O, CO2) in the mantle incipient melting captured by a multi-component model %+ Institut des Sciences de la Terre d'Orléans - UMR7327 (ISTO) %+ Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG) %A Massuyeau, Malcolm %A Morizet, Yann %A Gaillard, Fabrice %< avec comité de lecture %B 21 st meeting of the International Mineralogical Association %C Johannesburg, South Africa %3 21 st meeting of the International Mineralogical Association %N GP5 – GEOLOGIC FLUIDS IN THE DEEP CRUST AND UPPER MANTLE - POSTER %P 226 %8 2014-09-01 %D 2014 %Z Sciences of the Universe [physics] %Z Sciences of the Universe [physics]/Earth SciencesConference papers %X The link between volatiles and mantle melting has so far been illuminated byexperiments revealing punctually, at a given P-T condition and under a specificchemical system, properties such as solubility laws, redox equilibria, and phaseequilibria. Our aim is to establish a multi-component model describing the Gibbs freeenergy of melt produced by mantle melting in presence of CO2-H2O: that arecarbonatite-carbonated melt-nephilinite-basanite and basalt with increasing degree ofpartial melting.Near solidus melts are dominated by carbonate-rich compositions, evolving towardsbasaltic compositions at higher temperatures. However, this carbonate-silicatetransition is complex, abrupt, and dependent on temperature, pressure and the chemicalcomposition of the system. In order to simulate partial melting in a variety of mantleconditions, we established a parameterization of the mixing properties allowing thecomplex activity-composition relationships for multi-component hydrated carbonatedmelts to be accounted for. Using the Margules formalism, this parameterization iscalibrated on crystal-liquid, graphite-liquid, fluid-liquid and liquid-liquid equilibriaobtained by experimental studies in the P-T range 1-10 GPa and 900-1800°C. We so faradjusted the activity of the SiO2 and CO2 melt components, which constitutes the mainpart of the silicated and carbonated frameworks. The SiO2-CO2 interaction reveals astrong non-ideality requiring a strongly asymetric Margules formulation. We alsodetermined the standard thermodynamic properties for the CO2 melt component and wehave refined the standard volume properties for liquid SiO2. %G English %L insu-01143273 %U https://insu.hal.science/insu-01143273 %~ OBSPM %~ INSU %~ UNIV-NANTES %~ BRGM %~ CNRS %~ UNIV-ANGERS %~ UNIV-ORLEANS %~ ISTO %~ OSUC %~ PSL %~ LPG %~ OBSPM-PSL %~ NANTES-UNIVERSITE %~ UNIV-NANTES-AV2022