The formation and evolution of the Mesozoic-Cenozoic continental tectonics in eastern China

Abstract:In the Wilson cycle proposed in the 1960s, the collision of tectonic plates which leads to closure of oceanic basins on both sides of plates marks the end of the cycle. In interpreting continental tectonics in the past 20 years, it seems that the above conclusion is not comprehensive. Diffusive and widely distributed intracontinental deformation suggests that the action of platecollision has not ceased. After the formation of the Paleo- Asian continent, tectonic deformation, magmatism and cratonic basin formation widely developed during Mesozoic-Cenozoic period in eastern China were possibly related to the progressive opening of the Indian Ocean and the Arctic Ocean as well as the subduction of the Western Pacific and Philippine oceanic plates. This paper intends to discuss the major tectonic events, structural properties, the formation background and the temporal and spatial distribution of Mesozoic-Cenozoic tectonics in eastern China. From Late Hercynian to Indosinian period, the Paleo-Asian continent was formed due to amalgamation of various tectonic blocks during the closure of the Paleo-Tethys. During Late Jurassic - Early Cretaceous, accompanied by the closure of the Mongo-Okhotsk ocean, the continent-continent collision gave rise to the formation of the Paleo-Asian continent. Thrust-nappe structures were formed during the intracontinental deformation. At the same time, the Western Pacific Isanagi plate was subducted obliquely, which caused superimposation effect from east to west. In the Middle- Late Cretaceous-Paleogene period, together with the transition from thickened crust to lithospheric thinning and transformation, the intracontinental extensional deformation approached its peak stage. Continental craton basins peneplanes were formed. From Late Eocene to early Miocene (40-23 Ma), the superposition of the motion of the Pacific plate turning in NWW direction, the spreading of the middle oceanic ridges of the Indian Ocean, and the continent-continent collision between the Indian-Australian and the southern part of the paleo-Asian plate induced the formation of the new tectonic landforms in eastern China. Affected by East Asia-Western Pacific riftand the Indian Ocean ridge spreading during Middle Pliocene and early Pleistocene, the eastern China continent experienced lithospheric mantle uplift, crustal thinning, marginal and intracontinental extensional deformation. These processes resulted in the successive formation of marginal seas, island arc, rift basins and eroded highland landscapes. During Early Pleistocene (0.9-0.8 Ma) - Late Pleistocene (0.01 Ma) period, the tectonic landforms of Eastern China were finally formed.