Hidden ocean legacy found in Central Asia’s mountains
The ancient Tethys Ocean may have played a major role in shaping Central Asia’s mountainous landscape during the age of dinosaurs, according to new research led by scientists from the University of Adelaide, Qazinform News Agency correspondent reports.
The study found that tectonic forces linked to the gradual closure of the Tethys Ocean drove repeated episodes of mountain building across Central Asia during the last 250 million years, including during the Cretaceous period when dinosaurs roamed the region.
Their findings suggest that these forces were also the main driver behind the rise and erosion of mountain ranges such as the Tian Shan and Altai.
Researchers analyzed hundreds of published thermal history models from across Central Asia, combining them with reconstructions of ancient plate tectonics, mantle activity and prehistoric climate patterns.
“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. Instead, the dynamics of the distant Tethys Ocean can directly be correlated with short-lived periods of mountain building in Central Asia,” said Dr. Sam Boone, who conducted the research as a postdoctoral researcher at the University of Adelaide.
The Tethys Ocean once stretched between ancient continents before gradually disappearing during the Mesozoic and Cenozoic eras. Scientists say the modern Mediterranean Sea is one of its last remnants.
According to co-author Associate Professor Stijn Glorie, the region’s present-day mountains are largely linked to the ongoing collision between the Indian and Eurasian tectonic plates. However, the new study suggests Central Asia also had a rugged landscape much earlier.
“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,” Glorie said.
Researchers believe the rollback of subducting oceanic slabs beneath the Tethys Ocean reactivated ancient geological fault zones across Central Asia, creating parallel mountain ranges thousands of kilometers from the Himalayan collision zone.
The team used thermochronology, a method that tracks how rocks cool as they rise toward the Earth’s surface during mountain uplift and erosion. Their analysis showed that climate and mantle-driven topography had little connection to long-term exhumation patterns in the region.
The researchers said the same approach could help explain poorly understood geological histories in other parts of the world, including the ancient breakup between Australia and Antarctica.
Earlier, Qazinform News Agency reported that fossilized shark teeth believed to date back 30–40 million years were found in Kazakhstan’s Mangistau region.
