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Abstract

Based on the latest heat flow data of mainland China and the fine crustal structure data, we calculate the thickness of thermal lithosphere for each heat flow measurement point by solving one - dimensional steady heat conduction equation. The results show that the thickness of thermal lithosphere varies greatly in different areas. By comparing the thickness between thermal lithosphere and seismic lithosphere of the three cratons in China, we concluded that: 1) The western part of the Tarim craton, the middle - upper Yangtze craton, the western part of the NCC and the southern part of the NCC still remain stable, while the eastern part of NCC, the lower Yangtze craton and the southeastern part of the Tarim craton were thinned significantly; 2) In the western NCC, the thickness of thermal lithosphere, seismic lithosphere, and rheological boundary layer(RBL) all thin from west to Yinchuan - Hetao depression in northeast and Fenwei depression in southeast; 3) In the east NCC, the thermal lithospheric thickness of Bohai Bay Basin and the southern part of NCC differs significantly. The thickness of thermal lithosphere in the southern part of NCC is about 60 km thicker than that in Fenwei depression, even though Fenwei depression is to the west of it and theoretically less influenced by subduction of the Pacific plate. 4) The thickness of thermal lithosphere, seismic lithosphere, and RBL of the Yangtze craton gradually decrease from west to east, which may be controlled by the subduction of the Pacific plate.