EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Paleoaltitudinal histories for the northern and southern margins of the Tibetan Plateau during the Late Cenozoic: revealed by GDGTs

Chihao Chen1,2,3, Yan Bai1,2, Xiaomin Fang1,2,3, Haichao Guo2,3, Weilin Zhang1,2, Qingquan Meng4, Qiang Xu5, Tao Zhang1,2,4, Tao Deng3,6,7, Jiankun He1,2, and Qinghu Chen1,2,3
Chihao Chen et al.
  • 1CAS Center for Excellence in Tibetan Plateau Earth Sciences, Chinese Academy of Sciences, Beijing 100101, China
  • 2CAS Key Laboratory of Continental Collision and Plateau Uplift, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
  • 3University of Chinese Academy of Sciences, Beijing 100049, China
  • 4School of Earth Sciences and Key Laboratory of Western China’s Mineral Resources of Gansu Province, Lanzhou University, Lanzhou 730000, China
  • 5Division of Key Laboratory of Carbonate Reservoirs, CNPC and Southwest Petroleum University, Chengdu, 610500, China
  • 6Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, 100044, China
  • 7CAS Center for Excellence in Life and Paleoenvironment, Beijing, 100044, China

As an important driver of global climate change during the Cenozoic, the uplift of the Tibetan Plateau (TP) has strongly influenced the origination and evolution of the Asian monsoon system, and therefore the aridification of central Asia. Over the last two decades, the application of stable isotope paleoaltimeters and the discoveries of mammal and plant fossils have greatly promoted the understanding of the uplift history of the TP. However, paleoaltitudinal reconstructions based on different paleoaltimeters have suggested differing outcomes and therefore remain controversial. Novel paleoaltimeters have therefore needed to be developed and applied to constrain the uplift history of the TP more accurately and effectively by comparing and verifying multi-proxies. Paleothermometers based on glyceryl dialkyl glycerol tetraethers (GDGTs) are widely used in terrestrial and ocean temperature reconstructions. In this study, GDGT-based paleothermometers were tentatively applied to the Gyirong Basin on the southern TP, and the Xining Basins on the northern TP, in an attempt to quantitatively reconstruct their paleoaltitudes.

Both soil and aquatic-typed branched GDGTs have been identified from Late Miocene to Mid-Pliocene (7.0-3.2 Ma) samples taken from the Gyirong Basin; their reconstructed paleotemperatures were 7.5±3.3°C and 14.2±4.5°C, respectively. The former temperature may represent the mean temperature of the terrestrial organic matter input area, while the latter may represent the lake surface temperature. The results would suggest that the lake surface of the Gyirong Basin during the Late Miocene to Mid-Pliocene was 2.5±0.8 km and that the surrounding mountains exceeded 3.6±0.6 km, implying that the central Himalayas underwent a rapid uplift of ~1.5 km after the Mid-Pliocene.

GDGT-based paleotemperature reconstructions using MBT'5ME values show that the Xining Basin dropped in temperature by ~10°C during the ~10.5-8 Ma period, exceeding that in sea surface temperatures and low-altitude terrestrial temperatures during these periods. By combining these results with contemporaneous tectonic and sedimentary records, we infer that these cooling events signaled the regional uplift with the amplitude of ~1 km of the Xining basins. Our results support that the TP was still growing and uplifting substantially since the Late Miocene, which may provide new evidence for understanding the growth, expansion and uplift patterns of the TP.

How to cite: Chen, C., Bai, Y., Fang, X., Guo, H., Zhang, W., Meng, Q., Xu, Q., Zhang, T., Deng, T., He, J., and Chen, Q.: Paleoaltitudinal histories for the northern and southern margins of the Tibetan Plateau during the Late Cenozoic: revealed by GDGTs, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-14073,, 2021.