New evidence suggests that key differences in the geographical nature of the Tibetan Plateau can be explained by how far the Indian tectonic plate has been pushed beneath the plateau.

A new study published in Nature Geoscience reveals that millions of years ago, rocks in western Tibet were being exhumed (brought from depth to the surface) much faster than rocks in central Tibet, reflected in the much more rugged topography in the west. This difference can be explained by how far the Indian tectonic plate has pushed under the plateau over millions of years as it collides with the Eurasian plate, researchers say.

The research team, led by scientists at Nanjing University and Lancaster University, carried out fieldwork at altitudes of nearly 4,800 metres, collecting granite and sandstone samples from the Rutog region in the west and the Gerze region in the central part of the plateau.

Subsequent laboratory analysis of these samples allowed the researchers to calculate how rapidly the rocks were brought to the surface from depth. By synthesising their new data with existing data from across the plateau, the researchers observed differences in the exhumation history of central and western Tibet over millions of years.

The researchers then used existing age data from volcanic rocks of specific chemistry to track how far the Indian plate had been pushed beneath the plateau over time, and found that variations in the extent to which India had been pushed beneath the plateau correlated with the spatial west versus central regions of fast and slow exhumation. The study therefore demonstrates that the extent of the Indian continental tectonic plate being forced beneath the Asian continent is a primary factor controlling east-west variation in exhumation of the plateau.

These findings offer a new understanding of the plateau's evolution and helps explain the differing topographies and crustal thicknesses of western and central Tibet.

Yani Najman, Professor of Tectonics at Lancaster University, who co-authored the study, said their findings will also help improve our understanding of how other mountain ranges around the world may have formed.

She said: “This research helps us to further our understanding of how mountain belts form. It focuses in particular on the spectacular Himalaya-Tibet region, which act as a ‘type example’ for understanding the processes responsible for mountain belt formation in general.

“This work offers a new explanation for the differences we see between the eastern and western parts of the Tibetan plateau.”

The study was supported by a Royal Society Newton Advanced Fellowship. The Royal Society launched this scheme to provide established international researchers with an opportunity to develop the research strengths and capabilities of their research group through training, collaboration and reciprocal visits with a partner in the UK.

This study is the result of Sino-British collaboration. The participating institutions include Nanjing University, the Guangzhou Institute of Geochemistry of the Chinese Academy of Sciences, Lancaster University, the Scottish Environmental Research Centre, the University of Glasgow, among others.

The lead author is Weiwei Xue, now at the Guangzhou Institute of Geochemistry of the Chinese Academy of Sciences, and a PhD student at Nanjing University when this research was carried out., The joint research leads are Xiumian Hu of Nanjing University and Yani Najman of Lancaster University.

The findings are detailed in the paper 'West versus Central Tibet exhumation difference influenced by Indian slab underthrusting'.

DOI: 10.1038/s41561-026-02043-9

Professor Yani Najman (credit Weiwei Xue)