Experimental Phase Equilibria: Data and Models

Michel Pichavant (1) , Bruno Scaillet (1) , Caroline Martel (1)

1 ISTO - Institut des Sciences de la Terre d'Orléans

Equilibria between silicate melts, crystalline and vapour phases essentially control major and trace element compositions of natural magmas and play an essential role in partial melting as well as in differentiation processes. The development of models of phase equilibria is a prerequisite for assessing the dynamics of magmatic processes, such as magma storage in a reservoir or magma ascent in a conduit. The interest of experimental phase equilibria is essentially twofold. (1) Experimental phase equilibrium results can put precise constraints on the magmatic conditions, either in the magma storage region or in the conduit. Knowledge of pre-eruptive parameters (P, T, H2O in melt, fO2, ...) is necessary for eruption models and consequently for the evaluation of volcanic risk. (2) Experimental phase equilibria constitute our main source of information for the calibration of the mixing properties of multicomponent silicate melts, and for the construction of thermodynamic models which are our tomorrow's tools for the simulation of magmatic processes.

Domains: Volcanology

Michel Pichavant, Bruno Scaillet, Caroline Martel. Experimental Phase Equilibria: Data and Models. ESF LESC exploratory workshop on « Gases in magmatic evolution : from depth to atmosphere, from micro to macro-sacle, from calculation to observation », 2003, Rome, Italy. pp.44-45. ⟨hal-00102666⟩