Investigations into the Tectonics of the Tibetan Plateau
Combined model of rigid-block motion with continuous deformation: Patterns of present-day deformation in continental China
-
Published:October 01, 2008
One of the critical questions of continental dynamics is whether the preliminary assumption of rigid plate rotation is applicable to a continental lithosphere that possesses a long history of geological evolution. Different theoretical models give diverse answers that are difficult to test because of the lack of coherent and reliable kinematical constraints. In this paper, we study kinematic patterns of present-day tectonic deformation (or crustal movement) of continental China on the basis of 1350 global positioning system (GPS) measurements in combination with active faults and seismic activity studies. The present-day tectonic deformation of continental China is characterized by a combination of rigid-block movement and continuous deformation. For example, the Tarim Basin, the Ordos, and South China behave as coherent blocks similar to oceanic rigid blocks without internal deformation, whereas the Tibetan Plateau and Tianshan seem to deform continuously with significant internal deformation. Mechanical and rheological properties of the lithosphere dictate the style of regional deformation. Regions of high rigidity behave with rigid block-like movements, and those of low rigidity are dominated by continuous deformation. Rheological flow in the lower crust and upper mantle plays an important role in controlling deformation of the upper crust. Present-day tectonic deformation of continental China can be described in terms of a combined model of rigid-block movement and continuous deformation.