Viscous inclusions in anisotropic materials: Theoretical development and perspective applications

The application of the viscous inclusion theory to the rheologically heterogeneous and non-linear lithosphere is discussed. By regarding a heterogeneous element as an ellipsoidal inclusion embedded in a hypothetical homogeneous equivalent matrix whose effective rheology is obtained through micromechanical homogenization and assuming that the conditions of scale separation are satisfied, the viscous inclusion theory forms the backbone of multiscale models for natural deformation and the accompanying texture and fabric development.