青海省地质调查院Chun-Tao Wang团队研究了西藏东部羌塘北部约11 Ma的印度克拉通地幔。2025年3月24日，《地质学》杂志发表了这一成果。

确定青藏高原下印度岩石圈的北界是理解印亚会聚机制的关键。由于地震解释相互矛盾，特别是无法在断层图像中区分俯冲的印度岩石圈和增厚的西藏岩石圈，其位置存在争议。研究组报告了一种基于喜马拉雅-西藏造山带羌塘北部最近发现的中新世（约11 Ma）煌斑岩岩石学和地球化学的新方法的结果。

通过绘制在地质年代表左侧的铅同位素比值（其与其他造山带煌斑岩有明显区别），它们的Pb-Nd-Os同位素表明其是太古宙（>2.7 Ga）印度克拉通地幔源。这是令人信服的证据，表明印度克拉通地幔向北俯冲了约600公里，并至少在11 Ma时到达西藏东部羌塘北部以下。这种大规模的克拉通岩石圈俯冲解决了相互竞争的地球物理解释，并在形成板内地形方面发挥了重要作用。

附：英文原文

Title: Indian cratonic mantle beneath northern Qiangtang in eastern Tibet ca. 11 Ma

Author: Jun Wang, Chuan-Bing Xu, Qiang Wang, Chris J. Hawkesworth, Yi-Gang Xu, Gong-Jian Tang, Derek Wyman, Andrew C. Kerr, Bing-Zhang Wang, Jin-Heng Liu, Wu-Fu Li, Shan-Ping Li, Yue Qi, Jie Li, Zhuo Xiao, Chun-Tao Wang

Issue&Volume: 2025-03-24

Abstract: Establishing the northern limit of Indian lithosphere under the Tibetan Plateau is key to understanding IndiaAsia convergence mechanisms. Its location is disputed due to conflicting seismic interpretations and in particular the inability to distinguish between the subducted Indian and thickened Tibetan lithospheres in tomographic images. We report the results of a new approach based on the petrology and geochemistry of Miocene (ca. 11 Ma) lamproites recently discovered in northern Qiangtang of the Himalayan-Tibetan orogen. They are clearly distinguished from other orogenic lamproites by lead isotope ratios plotting to the left of the geochron, and their Pb-Nd-Os isotopes indicate an Archean (>2.7 Ga) Indian cratonic mantle source. This is compelling evidence that Indian cratonic mantle underthrust northward for ～600 km and had reached below northern Qiangtang in eastern Tibet at least 11 Ma. Such large-scale underthrusting of buoyant cratonic lithosphere resolves competing geophysical interpretations and plays an important role in shaping intraplate topography.

DOI: 10.1130/G52845.1

Source: https://pubs.geoscienceworld.org/gsa/geology/article-abstract/doi/10.1130/G52845.1/653263/Indian-cratonic-mantle-beneath-northern-QiangtangredirectedFrom=fulltext