查看文章

We study systematically the relationship between olivine lattice preferred orientation and the mantle flow field that produces it, using the plastic flow/recrystallization model of Kaminski and Ribe [2001]. In this model, a polycrystal responds to an imposed deformation rate tensor by simultaneous intracrystalline slip and dynamic recrystallization, by nucleation and grain boundary migration. Numerical solutions for the mean orientation of the a axes of an initially isotropic aggregate deformed uniformly with a characteristic strain rate show that the lattice preferred orientation evolves in three stages: (1) for small times , recrystallization is not yet active and the average a axis follows the long axis of the finite strain ellipsoid; (2) for intermediate times , the fabric is controlled by grain boundary migration and the average a axis rotates toward the orientation corresponding to the maximum resolved shear stress on the softest slip …