Fluids and high pressure deformation in subduction zones

Subduction zones are the locus of dramatic events and where a true factory proceeds between 20 and 80km depth. Under these conditions fluids produced by metamorphic reactions linked to the transformation into blueschists and eclogites follow poorly known trajectories to reach the surface. The role of these fluids and their tight and complex relationships with deformation mechanisms at all scales remain to be better documented. The scientific goal of this work is to use rocks from exhumed metamorphic belts to better understand the distribution of deformation modes along the subduction interface. The link between fluid percolation and the genesis of brittle deformation patterns, interpreted as a potential record of deep seismic activity, will be investigated. The coupling between long term geological observations and geophysical data on active subduction zones is crucial for (i) understanding mass and volatile transfer at the scale of the Earth and (ii) better assess seismic hazards above active subduction interfaces.