Thermal lithosphere structure of Tibet and adjacent regions based on a new thermal isostasy method

The thermal lithosphere structure of the Tibet is lack of constrained as the thermal heat flow measurement is nearly absent which has significantly limited the study of the uplift and evolution history of the Tibet. Based on the new thermal isostasy method, we constrain the thermal lithosphere of the Tibet and adjacent regions. The calculated surface heat flux in the surrounded Tarim, North China, and Yangtze blocks have a good match with the real measurements of surface heat flow. The thermal lithosphere is up to 200 km thick in most of the Lhasa Block, eastern Qiangtang and Songpan-Ganzi Block with a surface heat flux of 60 - 70 mW/m 2. The northwestern Tibet, where are the Sn propagation and low Pn area with low crustal density, has a relatively thin lithosphere with a thermal thickness of <80 km and surface heat flux of >80 mW/m 2. Thick and cold lithosphere in the northeastern Tibet indicated plate tectonics related continuous subduction/collision process plays an important role in uplift to northeastern-ward Tibet. The thin and hot lithosphere suggested that the lithosphere delamination might be the major uplift mechanism in the northwestern Tibet. The characteristic of surrounded lithosphere contributes to the controlling of the uplift mechanism.