Thermal State and Strength of the Lithosphere Beneath the Chinese Mainland  

作　　者：WANG Yang 

机构地区：[1]School of Earth Science and Resources,China University of Geosciences

出　　处：《Acta Geologica Sinica(English Edition)》2012年第4期810-827,共18页地质学报（英文版）

基　　金：supported by the 973 Research Project(Grant no. 2008CB425704) from the Ministry of Science and Technology,PRC;the National Natural Science Foundation of China(Grant nos 40572128,40376013,40104003);the Fundamental Research Funds for the Central Universities(Grant nos 2010ZD15 and 2010ZY23)

摘　　要：The temperature distributions of the lithosphere underneath the mainland of China were estimated by applying local isostatic equilibrium-constrained geothermal calculations. Maps of the lateral temperature variation at depths of 40, 70, and 100 km are presented for the whole Chinese continent, with the thermal thickness of the lithosphere is calculated. Lithospheric roots of 160-200 km thickness underlie Tarim and the Upper Yangtze Korean platform. In general, the Tibetan plateau lithospheres, whereas thinner thermal lithospheres platform, but are absent beneath the entire Sino- and fold belts to the north have warm but thick have been identified in northern Tibet and central Tian Shan around Issyk-Kul Lake. The warm and soft lithosphere in the Tibetan plateau and Tian Shan are caused by uniform north-south shortening, which may represent a snapshot of the early stage of convective thinning of the convergent lithosphere. However, the lithospheric thinning beneath northeastern China might be related to volatile infiltration by dehydration of the deeply subducting Pacific slab during the Cenozoic. Dry and wet upper mantle rheology display ＂jelly sandwich＂ and ＂cr^me brfil^e＂ pictures, respectively, demonstrating the mechanical behaviour of the Chinese lithosphere outside the Tibetan plateau. Considering a more geologically evident wet-mantle rheology, the ＂creme brulee＂ model can approximate the lithospheric rheology for the most earthquake-prone regions on the Chinese mainland.The temperature distributions of the lithosphere underneath the mainland of China were estimated by applying local isostatic equilibrium-constrained geothermal calculations. Maps of the lateral temperature variation at depths of 40, 70, and 100 km are presented for the whole Chinese continent, with the thermal thickness of the lithosphere is calculated. Lithospheric roots of 160-200 km thickness underlie Tarim and the Upper Yangtze Korean platform. In general, the Tibetan plateau lithospheres, whereas thinner thermal lithospheres platform, but are absent beneath the entire Sino- and fold belts to the north have warm but thick have been identified in northern Tibet and central Tian Shan around Issyk-Kul Lake. The warm and soft lithosphere in the Tibetan plateau and Tian Shan are caused by uniform north-south shortening, which may represent a snapshot of the early stage of convective thinning of the convergent lithosphere. However, the lithospheric thinning beneath northeastern China might be related to volatile infiltration by dehydration of the deeply subducting Pacific slab during the Cenozoic. Dry and wet upper mantle rheology display ＂jelly sandwich＂ and ＂cr^me brfil^e＂ pictures, respectively, demonstrating the mechanical behaviour of the Chinese lithosphere outside the Tibetan plateau. Considering a more geologically evident wet-mantle rheology, the ＂creme brulee＂ model can approximate the lithospheric rheology for the most earthquake-prone regions on the Chinese mainland.

关 键 词：GEOTHERM RHEOLOGY STRENGTH continental lithosphere China 

分 类 号：P313[天文地球—固体地球物理学]