EGU21-14135
https://doi.org/10.5194/egusphere-egu21-14135
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Extreme variability of Tibetan thermal lithosphere 

Bing Xia1,2, Irina Artemieva1,3, and Hans Thybo1,4
Bing Xia et al.
  • 1State Key Laboratory of Geological Processes and Mineral Resources, School of Earth Sciences, China University of Geosciences, Wuhan, China
  • 2State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China
  • 3Department of Geophysics, Stanford University, Stanford, CA, USA
  • 4Eurasia Institute of Earth Sciences, Istanbul Technical University, Istanbul, Turkey

We present a thermal model for the lithosphere in Tibet and adjacent regions based on the new thermal isostasy method and our compilation of the Moho depth based on published seismic models. The predicted surface heat flow is in agreement with the few available, reliable borehole measurements. Cratonic-type cold and thick lithosphere (200-240 km) with a surface heat flow of 40-50 mW/m2 typifies the Tarim craton, the north-western Yangtze craton, and most of the Lhasa Block that is possibly refrigerated by underthrusting Indian lithosphere. The thick lithosphere of the Lhasa block extends further north in its western and eastern segments than in its central section. We identify a North Tibet anomaly with a thin (<80 km) lithosphere and high surface heat flow (>80-100 mW/m2), possibly associated with the removal of lithospheric mantle and asthenospheric upwelling. Other parts of Tibet have an intermediate lithosphere thickness of 120-160 km and a surface heat flow of 45-60 mW/m2, with a patchy style in eastern Tibet. In the Qaidam deep sedimentary basin the lithosphere is about 100-120 km thick. The heterogeneous thermal lithosphere beneath Tibet suggests an interplay of several mechanisms as the driver of the observed uplift.

How to cite: Xia, B., Artemieva, I., and Thybo, H.: Extreme variability of Tibetan thermal lithosphere , EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-14135, https://doi.org/10.5194/egusphere-egu21-14135, 2021.

Display materials

Display file