GSA Connects 2021 in Portland, Oregon

Paper No. 202-9
Presentation Time: 10:25 AM


WANG, Yu, LIU, Songnan and ZHOU, Liyun, Institute of Earth Sciences, China University of Geosciences (Beijing), Haidian District, Beijing, 100083, China

For the intracontinental deformation and orogeny, the tectonic stress derived from the continental margin or from the up-welling mantle, moreover how the horizontal stress transmitted from the margin to the interiors are still unknown. However, the continental margin and intracontinental syn-kinematic deformation and timing similarity, magmatism and sedimentation can clearly show the processes of the tectonic stress transmission, as well constrain initial and continuous subduction-collision along the margin. These deformation features are as elastic deformation, the progressive deformation and the magmatic flow represent the plastic deformation. The rapid and quick erosion and short sedimentation indicate the initial response of the subduction on the continental margin.

The Mesozoic tectonics in eastern China is a best example to show these fundamental relationships of geological response-tectonic stress transmission. During the deformation of continental blocks, the magnitude of tectonic stress generally decreases with increasing distance from the margin of the block, reveal the age of the NE–SW-trending tectonic belts as ~180–155 Ma, where the deformation of the continental margin occurred 10–20 Ma earlier than that of the continental interior. Although the kinematics of deformation are similar for the interior and the margin of the eastern China, strain decreases with increasing distance from the margin. The patterns and mechanisms of plastic strain follow a simple rheological model. Moreover, the pre-existing orogenic or deformational belts as weak zones are the primary conduits for the transmission of tectonic stresses in different regions, with number of granitic intrusion, volcanic eruption and sedimentation.