The Tibetan Plateau, where average elevations exceed 4,500 metres and ten of Asia's largest rivers rise, has long posed a puzzle: how did its vast interior gain its height? An international team of Chinese and UK geoscientists, including University of Glasgow researchers, has now shown that the plateau's western and central regions have distinct geological histories, and that the difference records the progress of the Indian plate as it moved beneath the Asian plate.
The team carried out field surveys at Gerze in the central plateau and Rutog in the west during the summers of 2017 to 2019, shipping samples to Glasgow for analysis. Using low-temperature thermochronology and geochronological techniques, they reconstructed how rocks were exhumed towards the surface and how the landscape's elevation evolved. Uplift in the two regions differed markedly between 45 and 20 million years ago, precisely the period when the Indian slab underlay the west but had not yet reached the centre.
The study, published in Nature Geoscience, involved Glasgow's School of Geographical and Earth Sciences and the Scottish Universities Environmental Research Centre, alongside PhD researchers from Nanjing University in a three-year collaboration. The authors describe the result as the first convincing evidence tying the plateau's contrasting topography to the geometry of Indian plate underthrusting, a finding with implications for understanding how continental collisions build the planet's highest landscapes.