Explore fluid-mediated processes at convergent plate boundaries through a chlorine-centric lens in this 49-minute AGU Fall Meeting lecture. Delve into the Daly Lecture presented by J. Selverstone from the University of New Mexico, focusing on volcanology, geochemistry, and petrology. Gain insights into the role of chlorine in subduction zone dynamics and its implications for fluid-rock interactions, element mobility, and volcanic processes at plate boundaries.