A new biologic paleoaltimetry applied to the paleo-Qaidam Lake sedimentary sequences indicating Late Miocene rapid uplift of northern Tibet Plateau
- 1Key Laboratory of Desert and Desertification, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
- 2National Key Laboratory of Arid Area Ecological Security and Sustainable Development, Chinese Academy of Sciences, Urumqi 830011, China
- 3State Key Laboratory of Tibetan Plateau Earth System Science, Resources and Environment (TPESRE), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
- 4Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China
- 5Xinjiang Research Center for Mineral Resources, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China
- 6School of Geographical Sciences & Cabot Institute, University of Bristol, Bristol BS8 1SS, UK
- 7Guangdong Provincial Key Laboratory of Geodynamics and Geohazards, School of Earth Sciences and Engineering, Sun Yat-sen University, Zhuhai 519082, China
- 8Key Laboratory of Arid Climate Change and Disaster Reduction of CMA & of Gansu Province, Institute of Arid Meteorology, Lanzhou 730000, China
- 9School of Earth Sciences & Key Laboratory of Mineral Resources in Western China (Gansu Province), Lanzhou University, Lanzhou 730000, China
- 10Senckenberg Research Institute, Frankfurt am Main; Steinmann Institute, Bonn University, Bonn 53115, Germany
The Tibet Plateau is the world’s highest inhabited terrain, with an area >2.5×106 km2 and an average elevation >4000 m asl. Its uplift has been regarded as the main factor driving the evolution of the Asian monsoon regime and alpine biodiversity. The Miocene epoch is now deemed critical for understanding the timing of the attainment of the highest paleoelevation of the Tibet Plateau, the development of the modern Asia monsoon regime, and the acceleration of the evolution of alpine biodiversity. However, the northern Tibet Plateau remains poorly investigated.
Tsuga, Podocarpus, Abies, and Picea are four typical montane conifer genera. Although influenced by factors such as precipitation, geographical location, and soil properties, these taxa have elevation-specific habitats in Asia: Tsuga and Podocarpus usually grow at middle elevations (300 to 3500 and 600 to 2000 m asl, respectively) whereas Abies and Picea grow at higher elevations (500 to 4700 and 300 to 4700 m asl, respectively). Therefore, the representation of these genera in pollen assemblages can be used to reconstruct paleoelevation.
We tested new pollen analysis from Miocene sedimentary sequences of Huaitoutala section, and compiled them with other three sites (Core Sino-German-1, Core KC-1, and Yahu section in the Qaidam Basin (paleo-Qaidam Lake), northern Tibet Plateau. We selected these pollen records of Tsuga, Podocarpus, Abies, and Picea to build a new paleoaltimetry to construct two parallel midrange paleoelevation sequences in the northern Tibet Plateau at 1332 ± 189 m and 433 ± 189 m, respectively, during the Middle Miocene (~15 Ma). They increased rapidly to 3685±87 m in the Late Miocene (~11 Ma) in the east, and to 3589±62 m at ~7 Ma in the west. Our estimated rises in the east and west parts of the northern Tibet Plateau during 15-7 Ma, together with data from other Tibet Plateau regions, indicate that during the Late Miocene the entire plateau may have reached a high elevation close to that of today, with consequent impacts on atmospheric precipitation and alpine biodiversity.
How to cite: Miao, Y., Fang, X., Sun, J., Xiao, W., Yang, Y., Wang, X., Farnsworth, A., Huang, K., Ren, Y., Wu, F., Qiao, Q., Zhang, W., Meng, Q., Yan, X., Zheng, Z., Song, C., and Utescher, T.: A new biologic paleoaltimetry applied to the paleo-Qaidam Lake sedimentary sequences indicating Late Miocene rapid uplift of northern Tibet Plateau, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-17424, https://doi.org/10.5194/egusphere-egu23-17424, 2023.
