中国地质科学院地质研究所侯增谦、中国科学院地质与地球物理研究所刘丽军和中国科学技术大学张海江等合作，研究揭示了新生代青藏高原的向东生长受印度板块的撕裂控制。相关论文于2024年3月7日发表在《自然—地球科学》杂志上。
该研究团队进行了多尺度地震层析成像，以提供青藏高原东部地区下印度地幔岩石圈的修正结构。研究结果表明，印度的地幔岩石圈目前沿着约26°N的方向垂直撕裂，其北部向东北方向浅俯冲，南部向东急剧俯冲进入地幔过渡带。研究对其构造和岩浆记录的分析发现，其与50Myr前的板块撕裂的进退迁移一致。
研究人员认为，大约在35Myr以前，刚性的扬子克拉通岩石圈撕裂了侵入的克拉通印度地幔岩石圈，导致了分叉的浅俯冲。随后的中新世印度东南部地幔岩石圈的回退，引发了一场巨大的涡轮发动机般的流动，该流动引导着高原顶部和下部地幔围绕东部构造结的顺时针旋转，导致青藏高原的差异向东生长。
据悉，青藏高原的形成通常被归因于是新生代印度—亚洲碰撞的结果。然而，印度地幔岩石圈(特别是青藏高原东部下方)沿走向变形的成因，及其对青藏高原向东生长的影响尚不清楚。
附：英文原文
Title: Cenozoic eastward growth of the Tibetan Plateau controlled by tearing of the Indian slab
Author: Hou, Zengqian, Liu, Lijun, Zhang, Haijiang, Xu, Bo, Wang, Qingfei, Yang, Tiannan, Wang, Rui, Zheng, Yuanchuan, Li, Yanchong, Gao, Lei, Yu, Nian, Wang, Xiaolei, Miao, Zhuang, Han, Shoucheng, L, Qingtian
Issue&Volume: 2024-03-07
Abstract: Formation of the Tibetan Plateau is generally ascribed to the Cenozoic India–Asia collision. However, the origin of along-strike deformation of the Indian mantle lithosphere, especially beneath the eastern Tibetan Plateau region, and its effect on the plateau’s eastward growth remain unclear. Here, we conduct multiscale seismic tomography to provide a revised structure of the Indian mantle lithosphere beneath the eastern Tibetan Plateau region. Our results demonstrate that the Indian mantle lithosphere is currently torn vertically along~26° N, with its northern portion shallowly subducting northeastwards and the southern portion steeply subducting eastwards into the mantle transition zone. Analysis of tectonic and magmatic records is consistent with advancing and retreating migration of the slab tear after about 50 Myr ago. We suggest that the rigid Yangtze cratonic lithosphere tore the intruding cratonic Indian mantle lithosphere approximately 35 Myr ago, resulting in diverging shallow subduction. The subsequent Miocene rollback of the southeastern Indian mantle lithosphere is proposed to induce a giant turbo-engine-like flow that caused clockwise rotation of the plateau crust and underlying mantle around the eastern syntaxis, leading to differential eastward growth of the Tibetan Plateau.
DOI: 10.1038/s41561-024-01382-9
Source: https://www.nature.com/articles/s41561-024-01382-9