During shortening, unless material is lost, transpression produces vertical thickening in the crust. Transpression that occurs on a regional scale along plate boundaries is characterized by oblique convergence. More locally, transpression occurs within restraining bends in strike-slip fault zones.
When shortening occurs, unless there's loss of material, transpression causes vertical thickening of the crust.  Transpression that happens on a large scale along plate boundaries is marked by oblique convergence. On a smaller scale, it occurs within bends in strike-slip fault zones.