Abstract

Earth’s lithospheric behavior notably depends on its mantle properties and dynamics. Therefore, in order to fully understand Earth’s present-day or geological observations such as hotspot magmatism, surface tectonic motions, dynamic topography, it is often important to consider the interactions between Earth’s mantle and lithosphere. However, the nature and effects of the diverse interactions between Earth’s surface and mantle is still debated.

Here, I propose to use both 2D and 3D-spherical numerical models of whole-mantle convection self-generating plate-like tectonics at the surface in order to revisit and explain a diverse set of geological observations, and unravel mantle properties and dynamics. In the first part of my talk, I will demonstrate that model plume-lithosphere interactions can provide geodynamical constraints for paleogeographic reconstructions. In the second part of my presentation, I will show, using both models with a linear and a composite mantle rheology, how upper-mantle properties can control lithosphere dynamics, either favouring plate tectonics, or switching it off completely. I will briefly discuss how these results can be used in order to better constrain Earth’s mantle rheology.