Séminaire ISTeP - Jean-Arthur Olive

(chargé de recherche, ENS).

Feedbacks between extensional tectonics and surface processes

Major fault systems are the primary manifestation of localized strain at tectonic plate boundaries. Slip on faults creates topography that is constantly reworked by erosion and sediment deposition. This in turn affects the stress state of the brittle upper crust. Numerical models commonly predict that surface processes can modulate the degree of strain localization, i.e., the partitioning of strain onto a given number of master faults and/or the lifespan of individual faults. The detailed mechanisms, potential magnitude, and geological evidence for such feedbacks however remain debated. I will address this problem from the perspective of extensional plate boundaries, and at the scale of individual fault-bounded structures. In particular, I will discuss the impact of fluvial incision on the evolution of Basin-and-Range-style half-grabens, and the effect of sedimentation on seafloor spreading processes in the Andaman Sea.   

15/02/2019, Salle Fourcade à 12h30