Abstract: Palaeogeographically the South China palaeocontinent represents the extensive region of the southern parts of the Kunlun and Qinling Mountains,and is generally named South China.It includes the Yangtze,Cathaysian,Qiangtang-Qamdo landmasses as well as the Lhasa landmass separated from the Gondwana landmass group,and the Gyangze region on the northern margin of the Indian landmass.In the convergence of the China palaeocontinent,the Tarim and Qaidam landmasses were separated from the Yangtze landmass group and drifted to converge with the North China landmass at the end of the Early Palaeozoic.
The subduction of the oceanic crust and the convergence of the landmasses have the features of multistage development and the processes of collision and inlay in the form of point,line and surface.The South China palaeocontinent underwent three stages of evolution.The first stage covers the late Late Proterozoic to Early Palaeozoic,when the Pan-Yangtze landmass group was regulated for the first time.The isolated Tarim and Qaidam landmasses were split from the western Yangtze landmass.Meanwhile,the eastern Yangtze landmass was converged with the Cathaysian landmass to form the South China palaeolandmass,and further to come into collision with the extended North China landmass at one point.In the second stage during the Late Palaeozoic,the Pan-Yangtze landmass group was broken up,and the narrow Jinshajiang ceanic basin extended.The Qiangtang-Qamdo and Zongza laadmasses were separated from the Yangtze landmass.The third stage begins with the Ladinian (Middle Triassic).Due to the subduction of the western Palaeo-Pacific Ocean,the migration of the South China landmass from east to west and the south- and northward subduction of the remnant Bayan Har oceanic basin,the epicontinental arc was formed along the Kunlun-West Qinling Mountains in the northern part,and the island-arc zone occurred along the Jinshajiang-Yushu region in the southern part.Then the Bayan Hat sea basin was infilled and disappeared to transform into a foreland basin,resulting in the formation of the obductively orogenic zone on the western margin of the South China landmass.However,the Lhasa landmass and Gyangze region were converged with the South China landmass during the late Late Mesozoic to Tertiary.