Fig. 3: Influence of strain rate on deformation mechanisms.
From: Periclase deforms more slowly than bridgmanite under mantle conditions
This figure corresponds to approximately 30 GPa, 2,000 K, where the experimental (exp.) data of Girard et al.3 (symbols) can be compared to numerical models (lines). At laboratory stresses and strain rates numerical models based on dislocation glide are in fair agreement with experimental data and show that bridgmanite (Bdm) is stronger than periclase (Per). At mantle strain rates, creep (Weertman creep modelled by 2.5D DD in periclase (see text) and pure climb creep (PCC) in bridgmanite) is controlled by ionic diffusion, which leads to an inversion of rheology, with periclase deforming more slowly than bridgmanite.
