Indosinian collision-orogenic system of Chinese continent and its orogenic mechanism
中国大陆印支碰撞造山系及其造山机制

The closure of the large Paleo-Tethyan Ocean at the T3-J2 period induced collisions of many microterrains and formed huge Paleo-Tethys orogenic belts in South Asia, also known as Indosinian orogenic belts. The Indosinian orogenic belts of the Chinese continent and adjacent areas shows a "T"-shaped composite orogeny. Studies have shown that the western Indosinian "Bayan Har-North Qiangtang-South Qiangtang-Lasha" orogenic belts were formed in the Paleo-Tethys setting of multi-ocean basins, multi-terrains and multi-island arcs". Subduction and closure of Paleo-Tethyan ocean basins yielded a wide accretional orogeny in island arcs, accretionary wedges and high-pressure metamorphic belts, as well as large-scale orogenic collage due to multi-terrains collision orogeny charecterized by crustal deformations of syn-cleavage folds, thrusts and strike-slip faults. The eastern Indosinian orogenic system is the direct collision result between the North China and Yangtze blocks. The Songpan-Ganzi and South Qinling orogenic belts located above the Yangtze passive margin show large-scale deep decollement orogenic mechanism between the Upper Proterozoic metamorphic basement and Paleozoic-Triassic covers, as well as intensive shear strain of the Yangtze upper crust. The deep subduction (>100km) of the Yangtze crust and root extrusion mechanism yielded large-scale high pressure/ultra-high pressure metamorphic belts exposed in the Dabie-Sulu orogenic belt.