RheoMan: a five-year, ERC-funded (Advanced Grant), project to model the rheology of the Earth's mantle

Jul 23, 2015 A weak layer Results

Two new publications on plastic deformation of MgSiO3 post-perovskite just appeared on line in Physics and Chemistry of Minerals

In her PhD project, A. M. Goryaeva studies defects and plasticity in MgSiO3 post-perovskite. In the first of these two publications it is studied at the atomic scale how the very anisotropic post-perovskite structure responds to a rigid body shear.

 

 

This study allows to track the easiest shear paths in this crystal structure and to predict potential easiest slip systems.

 

Then, the [100] dislocations are modeled at the atomic scale demonstrating that these defects glide very easily in the (010) plane. This contrasts with the strong increase of lattice friction observed with increasing pressure in bridgmanite and leads potentially to a strong viscosity contrast in the D" layer.

 

 

More in:

  • A.M. Goryaeva, Ph. Carrez & P. Cordier (2015) Modeling defects and plasticity in MgSiO3 post-perovskite: 1- Generalized stacking faults. Physics and Chemistry of Minerals, doi: 10.1007/s00269-015-0762-9.

  • A.M. Goryaeva, Ph. Carrez & P. Cordier (2015) Modeling defects and plasticity in MgSiO3 post-perovskite: 2- screw and edge [100] dislocations. Physics and Chemistry of Minerals, doi: 10.1007/s00269-015-0763-8.

Both available in Open access