Integrating fossil and extant plant communities to calibrate paleoelevation of the Qinghai-Tibet Plateau

The formation of the Qinghai-Tibet Plateau has long been debated, despite the various proxies used to estimate its paleoelevation. Here, we introduce a novel method to calibrate paleoelevation by comparing the fossil and extant plant communities in the Qinghai-Tibet Plateau. Our estimation confirms that the uplift of the plateau was an episodic and heterochronous process. Specifically, the Lhasa Terrane was already elevated by 1 km before the initial India-Asia collision. During the first orogenic stage, the Qiangtang Terrane rose faster than the Lhasa Terrane, attaining 3 km in the late Eocene. In the second stage, the Lhasa Terrane underwent rapid uplift, reaching 3 km in the Oligocene. By the Middle Miocene, both the Qiangtang and Lhasa terranes had achieved an elevation of 4 km. The Himalaya rose by at least 2 km after the Pliocene. Our biological knowledge-based findings contradict the previous geological evidence-based reports, which posited that the plateau had reached an elevation of 4-5 km during the Eocene. We provide a new perspective on the plateau ' s uplift history based on biological evidence, which has the potential to reconcile the confusion arising from contradictory proxies.