|
The Chinese continent has three Precambrian cratons: Yangtze, Tarim, and Sino-Korean (also called North China) craton. The subduction of the Pacific and Philippines oceanic plates in the east and the collision with the Indian plate in the southwest during the Cenozoic strongly influenced the Chinese continent, and dynamically shaped the contemporary tectonic framework and the geographic relief of the continent. Consequently, the three cratons were influenced by the events, which possibly result in cratonic lithosphere thinning. The present Sino-Korean "craton" is one of the most active continental blocks in the world, and has thin lithosphere and strong seismic and thermal activities. Except for the Sichuan basin on the west of the Tibetan plateau, the Yangtze craton also has a thin lithosphere. Previous studies showed that the Sino-Korean and Yangtze cratons have been strongly destructed since the Mesozoic, however, the Tarim craton seems not to be destructed because its present lithosphere is cool and rigid. Recent geological evidences showed that the Tarim craton was part of ancient Western China craton, broken in the Cenozoic during the Indo-Asian collision. New evidences from our seismic and seismic-thermal models of the present uppermost mantle and of the lithospheric base topography showed that the lithospheric base of the Tarim has also been destructed and thinned during the Cenozoic.
|
