Program > Browse abstracts by speaker > Perrillat Jean-Philippe

Carbonatite melts can play a crucial role in the deep carbon cycle, as major carbon carriers from the deep Earth to its surface. Indeed, due to their low viscosities (

In this work, we performed high-pressure/high-temperature infiltration experiments in peridotite minerals powders to investigate mantle metasomatism by those unusual magmas, as well as the dynamics and morphology of carbonate melt migration. Using real-time computed tomography (CT) imaging under extreme conditions (PSICHE beamline, Synchrotron SOLEIL) and Raman plus SEM-EDS on quenched samples (Laboratoire de Géologie de Lyon), we provide insights into the kinetics of melt infiltration and reactivity. Time-lapsed CT images exhibit the diffusive dynamics of capillary flow, and the observed infiltration rates of 5.3 – 5.9 mm/h confirm the high mobility of carbonate liquids relative to silicate ones. Chemical reactivity corresponding to matrix wherlitization was also observed on a time scale comparable to that of the melt flow. Further experiments on the assimilation of orthopyroxene into carbonate melts at 2 GPa-1000°C provide constraints on the mechanism and kinetics of orthopyroxene dissolution, and its effect on the evolution of the composition and physical properties of the melt.