Strain modeling of transpressional and transtensional deformation

Transpressional and transtensional deformation zones can be modeled as a simple shearing with a simultaneous component of pure shearing in the plane perpendicular to the zone. Four general types of deformation (pure shear- and wrench-dominated transpression/transtension) are distinguished on the basis of the instantaneous stretching axes. For each of these deformations the orientation of the finite strain ellipsoid, instantaneous stretching directions, flow apophyses, and rotation paths of lines and planes can be calculated. These quantities are reflected in the fabrics of deformed rocks which can be used to qualitatively or quantitatively describe the deformation of both active and ancient transpressional/transtensional deformation zones. -from Authors