WEAKENED ZONES IN THE CONTINENT: THEIR EFFECTS TO THE TECTONIC STRESS TRANSMISSION

Intracontinental deformation and orogeny are popular, however, the tectonic stress transmitted from the margin to the interiors is still unknown. Based on field investigations in several reactivated tectonic belts such as the Mesozoic Taihang Mountain belt, Cenozoic Tianshan and late Mesozoic Qingling-Dabie orogenic belts in China, we found that the magnitudes of deformational strain decrease from the continental margins to the interior. Moreover, the Pre-existing orogenic or deformational belts as weak zones are the primary conduits for the transmission of tectonic stresses in different regions. The sand-box physical modeling indicates that the vertical and horizontal weak zones are with different activation: the former take a role for the filtered tectonic stress and the latter as a shear zones to transmitting the tectonic stress. The patterns and mechanisms of plastic strain follow a simple rheological model.