The release of fluids from the subducting slab is considered to be a key process for subduction zone geodynamics, from controlling arc volcanism, to seismicity and tectonic exhumation. High-pressure slab fluids are major vectors of mass transfer to the mantle wedge and significantly contribute to the element cycling, however, many details of fluid composition and mechanism of fluid expulsion are yet to be thoroughly understood. Subducted serpentinites are considered the main source of water and also carry redox sensitive elements such as C and S. During dehydration, C-S bearing aqueous fluids can react with other slab lithologies and/or mantle wedge in a process that, ultimately, influence the redox budget of the mantle, and govern the physico-chemical evolution of magmas in the Earth’s lithosphere. In addition, antigorite dehydration reaction is characterized by a solid volume change that creates a transient fluid-filled porosity and, thus, the main pathways for fluid drainage in subduction zones.
In this session, we foster cross-disciplinary collaboration among petrologists and geochemists to probe and integrate petrological and geochemical approaches to comprehend subduction zone fluids composition and dynamics of fluid expulsion/fluid rock interactions. We welcome contributions addressing research that tackles geochemical, petrological, micro-structural and experimental constrains of the dynamics of fluid-mediated processes that contribute to mass transfer and volatile cycling in subduction zones.