The thermo-mechanical strength distributions of the lithosphere underneath Chinawere obtained by 3-D crustal velocity model of China, local isostasy equilibrium constrained geothermal inversion, and 4-layered rheological model of lithosphere. Map of the lateral strength variation at compression condition is presented for whole China continent, and the thermal thickness of the lithosphere is also calculated. The relative strength ratio of crust/mantle (SC/SM) in the vast region of Tibetan plateau is larger than 10, corresponding to a stronger crust but weak upper mantle. Off Tibetan plateau, the lithosphere of typical "jelly sandwich" rheology that SC/SM ratio is less than 1, occurs in Junggar, Tarim, Sichuan basin, and Dabieshan as well as the southeastern and northeastern part of Sino-Korean platform. However, the SC/SM ratios are larger than 3 in the northern part of Northeast China,Tian Shan and South China fold belt. The "crèmebrûlée" model is more suitable for describing the lithosphere rheology of these regions. For other portion of China, the SC/SM ratios are mainly in range of 1 to c.3, corresponding to a slight stronger crust and a weaker upper mantle. Accordingly, the most of China Mainland exhibit "crème-brûlée" layered lithosphere rather than "jelly sandwich" one, with exception of Junggar, Tarim and Sichuan basin as well as some areas in Sino-Korean platform. This result means that the lithosphere beneath most area of China continent is mechanically weak. It is the upper crust rather than the upper mantle portion bears the elastic stress. In earthquake-prone regions of China landmass, the mechanical behavior of crust and mantle is decoupled.


The continental area of China is made up of juxtaposed strongly deformed parts and relatively stable regions, and the crustal structure, lithosphere thickness and temperature distributions beneath China mainland exhibits significant lateral variations (Wang, 2001).

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