The cycle of volatiles is intricately connected to the plate tectonic cycle. This journey begins along oceanic spreading centers, where the interplay between magmatism, tectonics and hydrothermal processes forms and alters the oceanic lithosphere, locking in vast quantities of H2O, C, S, as well as other volatiles and metals. When the altered lithosphere subducts, the coupling of deformation and metamorphic reactions channels the released volatiles into the subduction interface and the overlying mantle wedge, driving metasomatism and arc volcanism. The reactive pathways for volatile transfer are forged through the dynamic interplay of aqueous fluid–rock interaction, deformation, and metamorphism, under both seafloor and deep mantle conditions.

This session aims to connect the processes that create volatile pathways across tectonic settings. We invite contributions addressing aqueous fluid–rock interactions, with a particular focus on: (i) oceanic alteration and associated changes in volatile storage and redox budget, (ii) volatile transfer in aqueous COHS fluids, (iii) isotopic tracers of fluid–rock interaction, and (iv) feedbacks between chemical reactions and rock mechanics.

We welcome studies using field observations, experiments, as well as numerical and thermodynamic modeling to trace the cycling of volatiles across geological settings.