Zhiqin Xu, Jingsui Yang, Haibing Li, Shaocheng Ji, Zeming Zhang, Yan Liu
Institute of Geology, CAGS
Abstract:The collision between India and Asia is the most spectacular tectonic event on Earth during the Cenozoic, resulting in the uplift of the Tibetan plateau and surrounding orogenic belts as well as a lot of material escaping toward the east and southeast. In this paper, the Tibetan plateau was divided into the following tectonic units: (1) the central Tibetan plateau including east Kunlun, Bayanhar-Songpanganzi, Qiangtang, and north Lhasa areas; (2) the Gangdese-Himalayan main subduction-collision belts consisting of Gangdese Andes-type subduction belt and the Himalayan-type collision belt; (3) surrounding transpressional orogenic belts characterized by thrusting and strike-slip faulting which include Western Kunlun-Altyn-Qilian transpressional belts in the north, Longmenshan-Jinpinshan belt in the east, Sino-Burma belt in the southeast, India-Pakistan-Afghanistan belt in the southwest; (4) lateral extrusion terrains including South Songpan, Lanping, Baoshan and Tenchong terrains bounded by large-scale strike-slip faults: Xianshuihe-Xiaojiang fault, Ailaoshan-Red river fault, Lancangjiang fault, Jiali-Gaoligong fault, Nabang fault and Sagaing fault around the eastern Himalayan Syntaxis, as well as Tianshuihai, Xindukushi, Kabuer and Afghanistan extrusion terrains around the western Himalayan Syntaxis.
Various constraints for the India / Asia collision tectonics have been discussed, such as: collision between a small wedge of Indian plate and the larger Asian Plate, the roles of the Eastern and Western corners of the Indian plate, the impact of normal and oblique collisions, large strike-slip faulting related to lateral extrusion, transpressional mechanism with both strike-slip faulting and thrusting kinematic features related to uplift of surrounding orogenic belts, and mantle structures beneath the Tibetan Plateau.