Speciation and cycle of volatile elements

Volatile elements (hydrogen, carbon, noble gases, halogens, sulfur) have low boiling points. They are major components of giant planets, in which their abundance is closely related to protosolar values, and of other bodies of the outer solar system. In contrast, bulk terrestrial planets only contain traces of volatile elements, which play a central role in most (bio)-geological processes. Volatiles are basic components of life on Earth, they are the main constituents of atmospheres and key elements of planetary interiors for their influence on physical properties materials and hence on internal dynamics. They are the most efficient agents for mass transfer between reservoirs, in particular between planetary interiors and the surface (“in” and “out” fluxes). Studying the speciation and distribution of volatiles in the solar system through observations, experiments and calculations on volatile-bearing minerals and other materials improves our understanding of their origin and distribution in terrestrial planets and other bodies of the solar system, of the composition of asteroids, terrestrial and giant planets interiors, and of the formation of planetary atmospheres.