Li Yanchong, Liu Lijun, Li Sanzhong, Peng Diandian, Cao Zebin, Li Xinyu
Department of Earth Science and Environmental Change, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Science, Beijing, China.
Nat Commun. 2024 Aug 6;15(1):6674. doi: 10.1038/s41467-024-51107-0.
The driving force behind the Cenozoic India-Asia collision remains elusive. Using global-scale geodynamic modeling, we find that the continuous motion of the Indian plate is driven by a prominent upper-mantle flow pushing the thick Indian lithospheric root, originated from the northward rollover of the detached Neo-Tethyan slab and sinking slabs below East Asia. The maximum mantle drag occurs within the strong Indian lithosphere and is comparable in magnitude to that of slab pull (10N m). The thick cratonic root enhances both lithosphere-asthenosphere coupling and upper-plate compressional stress, thereby sustaining the topography of Tibetan Plateau. We show that the calculated resistant force from the India-Asia plate boundary is also close to that due to the gravitational potential energy of Tibetan Plateau. Here, we demonstrate that this mantle flow is key for the formation of the Tibetan Plateau and represents part of a hemispheric convergent flow pattern centered on central Asia.
新生代印度-亚洲碰撞背后的驱动力仍然难以捉摸。通过全球尺度的地球动力学建模，我们发现印度板块的持续运动是由一股显著的上地幔流驱动的，该流推动着源自新特提斯洋板块向北翻转以及东亚下方俯冲板块下沉所形成的厚印度岩石圈根。最大的地幔拖曳力出现在坚固的印度岩石圈内，其大小与板块拉力相当（10N·m）。厚克拉通根增强了岩石圈-软流圈耦合以及上覆板块的压应力，从而维持了青藏高原的地形。我们表明，计算得出的印度-亚洲板块边界阻力也与青藏高原的重力势能所产生的阻力相近。在此，我们证明这种地幔流是青藏高原形成的关键，并且代表了以中亚为中心的半球形汇聚流模式的一部分。
