Webinar
FRIDAY 13 November at 14:00
 ESRF auditorium 

Speaker: Jean-Baptiste Jacob (ID19/ID11).

"Reaction-induced stress and fracturing in rocks: insights from in situ synchrotron X-ray diffraction and tomography"

Abstract
Chemical reactions between rocks and fluids are a fundamental driver of mechanical change in the Earth's crust. When minerals react with infiltrating fluids, the associated volume changes generate internal stresses that can deform, damage, or fracture the surrounding rock. This chemo-mechanical coupling process, known as reaction-driven fracturing, is central to the evolution of natural and engineered hydrothermal systems: it controls the permeability, and hence the fluid flow rate, as well as the precipitation of reaction products and mineralization rates. Harnessing and controlling this chemo-mechanical coupling is therefore critical for the sustainable exploitation of hydrothermal systems, whether for geothermal energy, georessource extraction, or permanent CO2 storage by in-situ mineralization. However, the mechanics of reaction-induced fracturing remain poorly constrained at the grain scale, where stress actually builds up. In this talk, I will present new avenues to investigate in situ how stress is generated in reacting rocks, using in situ synchrotron X-ray diffraction and tomography. Scanning 3D X-ray diffraction (s3DXRD) enables non-destructive mapping of intragranular stress and crystal deformation at grain scale, while X-ray phase contrast tomography tracks the concurrent development of fractures and porosity. Together, these techniques provide direct, quantitative insights into where minerals dissolve or precipitate, how stress builds up and drives fracture initiation and propagation, and how the resulting fracture networks control fluid pathways.