Grands Séminaires du CEREGE : Hugues Raimbourg (University of Orléans)

Summary : This presentation focuses on the deformation mechanisms operating at the core of faults in the upper crust, whether seismic or asismic. I will start with a brief general introduction on the different types of possible slip faults (stable or unstable), the mechanical conditions necessary for slip instabilities (i.e. earthquakes) to occur, and the different microscopic processes that can generate these slip instabilities. The main part of the presentation will then focus on natural fault rocks and the geochemical markers of slip that have occurred there. I will present two distinct geochemical markers: the first is the Raman spectrum of carbonaceous particles present in some faults, which provide information on both thermal history and finite deformation. The second is the fluid inclusions in the veins near the faults, which provide information on the variations of the fluid pressure during the seismic cycle.

The event will start with a coffee served in front of the Pasteur amphitheatre at 13:15.

The presentation will be in French and will be available for streaming (http://streaming-a.osupytheas.fr/embed/live.html)