Heat flow pattern in the mainland of China and ias geodynamic significance

On the basis of 723 heat flow measurements in the mainland of China and ove r 2000 data from the global heat flow data set, the authors compiled the he at flow map of the mainland of China and its adjacent areas to exhibit the overall variation of the heat flow pattern in the mainland. The heat flow p attern of the mainland is complex, and can not be simply summarized as "low in the north and west and high in the south and east". Significant differe nce exists between eastern and western China in the spatial pattern of heat flow. Divided by the 105 degrees E meridian, heat flow values in eastern C hina show a westward-decreasing trend; and a northward variation is observe d in western China. The high-heat flow regions correspond to tectonically a ctive belts such as Cenozoic orogens and extensional basins, where mantle h eat flow is high; and the low-heat flow regions correspond to stable units such as the Tarim and Yangtze platforms. This heat flow pattern is controll ed by India-Asia collision in the west and Pacific plate subduction in the east. The lateral variation in lithospheric strength corresponds to the hea t flow variation, and there is a generally reversely proportional relation between heat flow and lithospheric strength in the mainland of China. The m osaic pattern of present deformation in the mainland results from lateral r heological heterogeneity. The good coincidence between weak strength domain s and seismic zones demonstrates the intrinsic relation between the strengt h heterogeneity and regional seismicity pattern in the mainland of China.