An Ocean That No Longer Exists Could Explain the Origins of Central Asia’s Mountains

A vanished ocean may have helped sculpt Central Asia’s mountains.

Geologists from the University of Adelaide report that the forces shaping Central Asia during the age of dinosaurs may have originated far from the region itself. Their research points to the ancient Tethys Ocean as an unexpected influence on the rise and fall of mountains across the continent during the Cretaceous period.

Rather than relying on a single dataset, the scientists combined hundreds of previously published thermal history models created over roughly three decades of research in Central Asia. By treating this vast archive as a unified dataset, they were able to trace long-term geological patterns that individual studies could not easily reveal.

Rethinking Established Explanations

Central Asia’s rugged terrain is commonly explained as the outcome of interacting tectonic movements, shifting climates, and processes deep within Earth’s mantle acting over the last 250 million years. The new findings suggest this picture may be incomplete, especially when it comes to the role of climate and mantle activity.

“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 Dr Sam Boone, who was a post-doctoral researcher at Adelaide University when the research was conducted.

“Instead, the dynamics of the distant Tethys Ocean can directly be correlated with short-lived periods of mountain building in Central Asia.”

At the time, the Tethys Ocean stretched between major landmasses and played a central role in global plate motions. Its gradual closure during the Meso-Cenozoic period, which spans the last 250 million years, set off tectonic changes that rippled across Eurasia. Although the ocean itself has vanished, with only the Mediterranean Sea remaining, its influence appears to be preserved in the ancient mountains of Central Asia.

Mountain Building Before the Himalayas

“The present-day relief of Central Asia was largely built by the India-Eurasia collision and ongoing convergence,” said co-author Associate Professor Stijn Glorie, from Adelaide University’s School of Physics, Chemistry and Earth Sciences.

“However, during the Cretaceous periods, dinosaurs would have seen a mountainous landscape as well, similar to the present-day Basin-and-Range Province in the western USA.

“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 kilometers away from the Himalaya collision zone.”

Unlocking Geological Histories With Thermal Models

The study relied on thermal history models that enabled the research team to uncover geological processes and stages of Earth’s development that had not been identified before.

“These models were constructed using thermochronology methods and reveal how rocks cooled down when they are brought towards the surface during mountain uplift and subsequent erosion,” Associate Professor Glorie said.

“We analyzed a compilation of thermal history models in function of plate-tectonic models for the Tethys Ocean evolution, as well as deep-time precipitation and mantle-convection models.”

Applying the Approach Beyond Central Asia

Associate Professor Glorie, whose study was published in Nature Communications Earth and Environment, said the same approach could be applied to other areas of the globe.

“There are many parts on the planet where the drivers and timing for mountain building and/or rifting are poorly understood. For example, closer to home, the breakup history of Australia from Antarctica is somewhat enigmatic,” he said.

“Australia drifted away about 80 million years ago, but there is no obvious imprint of this in the thermal history record of either the Antarctic or Australian plate margins. Instead, they record much older cooling histories.

“We are applying the same approach as used in Central Asia to advance understanding of Australia-Antarctica break-up.”

Reference: “Deciphering mantle, tectonic and climatic drivers of exhumation” by Samuel C. Boone, Stijn Glorie, Sabin Zahirovic, Angus Nixon, Fun Meeuws and Fabian Kohlmann, 18 December 2025, Communications Earth & Environment.
DOI: 10.1038/s43247-025-03005-6

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