— GRAND SEMINAIRE DE THEME — The influence of crustal stress on the pathways and evolution of magmas

--- GRAND SEMINAIRE DE THEME ---
Magma does not always take a straight path to the surface, on the contrary it often moves along tilted or horizontal routes, forming sills and inclined sheets. These pathways, shaped by the Earth’s stress field, influence how fast magma rises and how much it evolves along the way. Some magma may stall underground for long periods, slowly changing its composition, while other batches move upward at speeds that do not allow any geochemical evolution. I will explore how stress controls these pathways and how ascent speed affects magma chemistry. Steeper pathways lead to faster ascent, while flatter ones allow for more interaction with surrounding rocks. I will present models linking the physics of magma ascent with geochemistry and show how stress patterns in the Earth’s crust shape the journey of magma and the eruptions we see at the surface.

** A noter: Le séminaire sera suivi d'une discussion informelle à la médiathèque, autour de quelques rafraîchissements.