Rocks are porous, multiphase, reactive materials whose mechanical response depends sensitively on deformation rate, pressure, and temperature. To grasp their effective rheology, one must consider processes that operate across a wide range of scales—from atomic‑level interactions involving vacancies and dislocations, fluid-rock interactions, to planetary‑scale models in which rock rheology is described as a long-term visco-elastic fluid flow.

The aim of this session is to bridge short‑time, small‑scale observations with long‑time, large‑scale processes. By integrating geodynamic investigations, experimental constraints, and theoretical formulations, we seek a unified understanding of the interacting mechanisms that drive geological deformation.

We invite contributions from all disciplines that explore how grain‑scale processes and rheology influence the overall mechanical behavior of geomaterials.