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

Summary : This presentation focuses on the deformation mechanisms that operate at the heart of faults in the upper crust, whether seismic or asismic. I will begin with a brief general introduction to the different types of slip that can occur on faults (stable or unstable), the mechanical conditions required 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 the slip that has occurred there. I will present two distinct geochemical markers: the first is the Raman spectrum of carbonaceous particles present in certain faults, which provide information both on thermal history and on finite deformation. The second is fluid inclusions in veins near faults, which provide information about variations in 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)