Rheology of Earth Materials :
Closing the gap between timescales in the laboratory and in the mantle

23 November 2023 - SIMaP: Seminar of Michaël COULOMBIER

Nanomechanical testing to understand the rheology of the Earth’s upper mantle

Science et Ingénierie des Matériaux et Procédés (SIMaP), Université Grenoble Alpes

Jeudi 23 novembre à 13:00
Salle séminaire du bâtiment ECOMARCH - SIMaP


Olivine is a silicate which controls the rheology of the Earth’s mantle down to ca. 410 km depth. Recently, a new deformation mechanism of olivine has been discovered where grain boundary sliding involves amorphization of grain boundaries under high stresses and further plastic flow along this amorphous layer (Samae et al., Nature, 2021). From there, as amorphous olivine is only available in the form of thin films, we had to rely on nanomechanical testing to characterize its mechanical properties.

In this presentation, I will show how we can use the Lab-on-Chip (LOC) tensile technique developed at UCLouvain to perform 2 years long relaxation tests on amorphous olivine. We achieved strain rates close to 10-12s-1 getting closer to tectonic strain rates (in the range 10-12 – 10-16 s-1).