Soutenance de thèse de Pierre Faure
22 November à 14 h 00 min - 17 h 00 min
Vendredi 22 novembre à 14h (Amphi 4 du Pôle Amphithéâtres Sciences sur le Campus des Cézeaux de Clermont-Ferrand), Pierre Faure soutiendra sa thèse intitulée :
“Comportement des éléments lithophiles lors de la formation du noyau terrestre.” (Behavior of lithohile elements during the Earth’s core formation)
The earliest history of the Earth was marked by accretion and core formation within about 100 Myr. The Bulk Silicate Earth (BSE) shows a depletion in siderophile elements coherent with a core differentiation within a magma ocean under a wide range of pressure, temperature and oxygen fugacity conditions. However, the impact of core formation on non siderophile elements has yet to be understood. Since the metal-silicate partition coefficient is a function of the physical and chemical conditions of metal-silicate differentiation, it is necessary to characterize the behavior of so-called lithophile elements and its evolution during Earth’s accretion in order to determine the effect of core formation on the distribution of these elements within our planet. We performed about 60 new high-pressure and high-temperature experiments of metal-silicate partitioning for several elements (uranium, thorium, rare earth elements, alkali elements) in order to determine their behaviour during Earth’s accretion. This study brings new constraints for Earth’s accretion models and refines our understanding of the core and BSE composition.