We study a class of time evolution models that contain dissipation mech-
anisms exhibited by geophysical materials during deformation: plasticity,
viscous dissipation and fracture. We formally prove that they satisfy a
Clausius-Duhem type inequality. We describe a semi-discrete time evolu- tion
associated with these models, and report numerical 1D and 2D traction
experiments, that illustrate that several dissipation regimes can indeed take
place during the deformation. Finally, we report 2D numerical simulation of an
experiment by Peltzer and Tapponnier, who studied the indentation of a layer of
plasticine as an analogue model for geological materials
