The work presented is a dossier presented to anobyainaccreditation to supervise research (HDR). It concerns the role of fluids in orogenic prisms. The presentation is organized around three approaches: (1) an integrated approach to iconic sites: a mature accretionary prism (the prism of Barbados) and a chain collision (Western Alps), (2) a methodological approach, and (3) a thematic approach to study processes poorly understood and to discuss problems of structure and dynamics of convergent orogens from subduction (eg Barbados) to the collision (eg Alps). We also show a few examples of the contributions of analog and numerical modeling to understanding orogenic systems and tools for calibrating the thermal history in this type of context. Finally, we discuss knowledge gaps concerning pension pressure, fluid dynamics and sediment mobilization aspects. A discussion is presented about the interactions between fluids and rheological evolution of orogenic prisms, before presenting research perspectives.
