The uplift history of the Tibetan Plateau holds the key to understanding the geodynamic processes that built the “Roof of the World,” as well as its far reaching impacts on regional and global climate and the evolution of Asian biodiversity. Among its many topographic features, the Gangdese Mountains which run along the southern margin of the Lhasa terrane are central to this story.
In a study published in Earth and Planetary Science Letters, researchers from Xishuangbanna Tropical Botanical Garden (XTBG) of the Chinese Academy of Sciences and their collaborators have for the first time quantitatively confirmed a rapid rise of the Gangdese Mountains in southern Tibet around 15 million years ago. They showed that hows that the range’s peaks soared to over 6 kilometres above sea level, roughly 1.5 – 2 km higher than today’s 4.5 km elevation or so.
To reconstruct this ancient event, the researchers combined fossil pollen and spore analysis, macrofossil records, and high-resolution climate vegetation models. By examining pollen assemblages from the Namling Basin in southern Tibet, they detected a sharp and abrupt ecological transition: a temperate–subalpine forest ecosystem gave way to alpine shrubland and shrub meadow within a short geological timeframe.
“This was not a gradual change driven by global climatic trends,but a local, catastrophic event that fundamentally reshaped the environment,” said LI Shufeng of XTBG.
Their modelling revealed that only a rapid surface uplift of 525 to 1,050 metres could explain the observed vegetation shift. This pushed the basin floor to an elevation exceeding 6 km, substantially higher than its present-day position.
While the Namling area rose sharply, contemporaneous pollen records from the central Tibetan Plateau (Lunpola Basin) show no such vegetation shift. This suggests that the 15 Ma uplift did not affect the entire Gangdese chain uniformly, likely due to east–west variations in Indian plate subduction and slab break-off.
The researchers further propose that the subsequent post-15-million-year decline elevation was driven by two major tectonic forces: the continued subduction of the Indian Plate beneath the Eurasian Plate, which created a downward drag on the southern Lhasa terrane, and the late Cenozoic east-west extensional collapse of the southern Tibetan Plateau.
“Our work demonstrates that pollen, when combined with climate modeling, can serve as a powerful altimeter for ancient landscapes,” said LI Shufeng.
Available online: 8 August 2026
