European Palaeobotany and Palynology Conference 2026

Resolving the elevation history of the Gangdese Mountains (GMs) is key to understanding the evolution of the entire Tibetan Plateau (TP). Multiproxy paleoelevation reconstructions indicate that the Namling (Wuyu/Oiyug) Basin, eastern GMs, experienced uplift from the late Oligocene to Middle Miocene, accelerating at ca. 15 Ma as inferred from a significant sediment provenance shift at that time. However, whether the rapid rise actually occurred still lacks direct evidence. In this study, pollen analysis of a well-dated section in the Namling Baisn, reveals a distinct vegetation shift from a temperate–subalpine forest to an alpine shrubland/shrub-meadow within the basin at ca. 15 Ma. By integrating pollen and megafossil records, and utilizing high-resolution climate-vegetation modeling, we demonstrate that this vegetation change resulted from a rapid uplift of the Namling Basin at ca. 15 Ma independent of end Mid-Miocene Climatic Optimum cooling. Based on our modeling results and contemporaneous pollen records from the Central TP, it seems the uplift at ca. 15 Ma was localized and cannot be extended to the entire GM chain. Subsequent subsidence may have been due to ongoing subduction of the Indian plate causing downward drag on the overlying southern Lhasa terrane combined with late Cenozoic east-west extensional collapse of the southern TP.