A NUMERICAL MODELING STUDY ON THE “ASTHENOSPHERE UPWELLING” OF SOUTH CHINA SEA
CUI Xuejun 1, XIA Bin 1, ZHANG Y H 2, LIU Baoming 1 , WANG Ran 1 and YAN Yi 1 (1. CAS Key Laboratory of Marginal Sea Geology and Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, GD 510640, China; 2. CSIRO Exploration & Mining, P.O.Box 1130, Bentley, WA 6102, Australia)
A numerical approach was used to explore the following key issues: how does the “asthenosphere upwelling” behave in terms of mechanism towards the expansion of the South China Sea? and how to evaluate such a behavior? Our results indicate that asthenosphere upwelling is much more efficient for the lithospheric thinning in the upper mantle but is still inefficient for crust thinning. It is the combination of mechanical extension and asthenosphere upwelling that proves to be the most efficient way to thin the entire lithosphere, and that represents the most likely driving force for the opening and spreading of the South China Sea.