Plant fossils discovered in rocks from the Tibetan Plateau and a new analysis of the area’s geochemistry are rewriting the uplift history of the region dubbed the “roof of the world.” This new research suggests that the story of the rise to its current dizzying height is far more complicated than just raising the roof.
Previous research has suggested that the plateau reached its current height — about 4.5 kilometers above sea level, on average — by at least 40 million years ago. But chemical evidence left in the region’s rocks suggest that couldn’t have happened before about 40 million years ago, researchers report in the March 1 Science.
Meanwhile, another team of researchers suggests that, as recently as 25 million years ago, the region wasn’t yet a flat, windswept plateau. Instead, it was a diverse landscape of steep mountains surrounding a deep valley where palm trees grew, the team reports online March 6 in Science Advances.
The uplift of the Tibetan Plateau altered atmospheric patterns in the region, causing the onset of monsoons in South Asia as well as the drying out of Asia’s interior, says Svetlana Botsyun, a paleoclimatologist at the University of Tübingen in Germany. In fact, the plateau is so tall that it also affects the atmosphere around the globe, altering temperature, precipitation, humidity and cloud cover, Botsyun says.