The study uses a big data approach built from hundreds of published thermal history models for Central Asia compiled over about 30 years. These models track when rocks cooled as they moved toward the surface during mountain uplift and subsequent erosion, providing a time-resolved record of tectonic activity.
Creation of Central Asia's landscape is usually explained as the result of interactions between tectonic forces, climate and mantle processes over the last 250 million years. The new analysis, however, suggests that climate change and mantle convection played only a minor role, with the region remaining arid for much of that interval.
"We found that climate change and mantle processes had only little influence on the Central Asian landscape, which persisted in an arid climate for much of the last 250 million years," said lead author Dr Sam Boone, who conducted the research while a post doctoral researcher at Adelaide University. "Instead, the dynamics of the distant Tethys Ocean can directly be correlated with short lived periods of mountain building in Central Asia."
The once extensive Tethys Ocean closed during the Meso Cenozoic era, which spans roughly the last 250 million years, and survives today only as the Mediterranean Sea. The team links tectonic changes in this retreating ocean basin to pulses of deformation thousands of kilometers inland.
Co author Associate Professor Stijn Glorie, from Adelaide University's School of Physics, Chemistry and Earth Sciences, said the present day relief of Central Asia mainly formed through the collision and continued convergence between India and Eurasia. According to Glorie, this collision built the major mountain belts that dominate the region today.
However, the researchers conclude that during the Cretaceous period, dinosaurs would also have seen a rugged landscape in Central Asia. They compare this earlier topography to the present day Basin and Range Province in the western United States, which consists of a series of roughly parallel mountain ranges and intervening basins.
"It is thought that the extension in the Tethys, due to roll back of subducting slabs of ocean crust, reactivated old suture zones into a series of roughly parallel ridges in Central Asia, up to thousands of kilometres away from the Himalaya collision zone," Glorie said. These reactivated structures provided pathways for rocks to be uplifted and cooled, leaving a recognizable signal in the thermal history models.
To test these ideas, the team analysed their compilation of thermal history models alongside plate tectonic reconstructions of the Tethys Ocean, as well as deep time precipitation and mantle convection models. By comparing the timing of cooling events in Central Asian rocks to changes in plate boundaries and subduction geometry, they identified correlations that point to the ocean as a key driver.
The research appears in Nature Communications Earth and Environment and demonstrates the potential of combining thermochronology with global geodynamic models. The authors argue that this integrative method can reveal previously hidden links between distant plate boundary processes and intraplate mountain building.
Glorie said the same approach could clarify the drivers of other poorly understood episodes of mountain building and rifting around the world. In particular, he highlighted the break up of Australia from Antarctica as a nearby example where the tectonic record is puzzling.
Australia separated from Antarctica about 80 million years ago, but the thermal history data from both continental margins mostly record older cooling events. There is little obvious imprint of that break up in the available thermochronology record, which raises questions about how the rift and subsequent seafloor spreading progressed.
The Adelaide team is now applying its Central Asia workflow to investigate the Australia Antarctica system. By integrating new and existing thermal history models with updated plate reconstructions and geodynamic simulations, they aim to better constrain when and how the two continents finally parted.
Beyond specific case studies, the researchers suggest that systematic global compilations of thermochronology data could transform understanding of how surface topography responds to changes at convergent and divergent plate margins. Such databases would allow scientists to test whether distant subduction dynamics, like those recorded in the Tethys Ocean, have shaped other continental interiors in similar ways.
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