• ISSN 2097-1893
  • CN 10-1855/P
崔冉,崔清辉,周元泽. 2024. 天山造山带壳幔速度结构及深部构造过程综述. 地球与行星物理论评(中英文),55(4):381-398. DOI: 10.19975/j.dqyxx.2023-034
引用本文: 崔冉,崔清辉,周元泽. 2024. 天山造山带壳幔速度结构及深部构造过程综述. 地球与行星物理论评(中英文),55(4):381-398. DOI: 10.19975/j.dqyxx.2023-034
Cui R, Cui Q H, Zhou Y Z. 2024. Seismic velocity structures and deep dynamic processes in the crust and mantle beneath the Tianshan Orogenic Belt. Reviews of Geophysics and Planetary Physics, 55(4): 381-398 (in Chinese). DOI: 10.19975/j.dqyxx.2023-034
Citation: Cui R, Cui Q H, Zhou Y Z. 2024. Seismic velocity structures and deep dynamic processes in the crust and mantle beneath the Tianshan Orogenic Belt. Reviews of Geophysics and Planetary Physics, 55(4): 381-398 (in Chinese). DOI: 10.19975/j.dqyxx.2023-034

天山造山带壳幔速度结构及深部构造过程综述

Seismic velocity structures and deep dynamic processes in the crust and mantle beneath the Tianshan Orogenic Belt

  • 摘要: 天山作为陆内造山带的典型地区,其深部构造一直是国内外地学界关注的热点问题. 天山造山带下方速度异常结构的分布特征,是天山造山带深部构造过程响应的深刻体现,对深入理解其活化机制具有重要的指示作用. 本文系统总结了天山不同区段的壳幔速度异常结构研究结果,讨论了天山造山带下方不同速度异常结构的形成机制以及天山隆升变形的动力学演化过程. 天山造山带不同区段的层析成像结果以及接收函数图像等多种地震学探测与GPS观测研究成果显示,区域速度异常结构分布特征与天山造山带及周边地区的地质构造特点、动力学演化过程具有相关性:天山造山带下方高速异常结构的倾斜方向、形态、位置,凸显了天山地区独特的陆内俯冲机制;不同区域的低速异常结构表明,存在软流圈热物质上涌形成的小地幔柱或小尺度地幔对流,以及岩浆底侵作用导致壳内物质发生部分熔融. 相关研究结果对进一步理解天山陆内俯冲、地壳缩短变形、岩石圈拆沉和软流圈热物质上涌等动力学过程具有重要意义,并对深入研究天山地区地震活动性分布规律提供有利的参考依据.

     

    Abstract: As a typical region of intracontinental orogeny, the Tianshan Orogenic Belt has consistently attracted significant scientific interest from geologists, both in China and internationally. The distribution of velocity anomalies beneath the Tianshan Orogenic Belt is of profound importance as it sheds light on the response of orogenic areas to activation mechanisms. In this study, crust-mantle velocity anomalies were investigated in different sections of the Tianshan Orogenic Belt, as well as the formation mechanisms of these anomalies and the dynamic evolution process of uplift and deformation. Different seismic methodologies were applied, including tomographic imaging, receiver function analysis, and GPS observations. The results of this systematic analysis indicate that regional velocity anomalous structures are closely correlated with the geological tectonic features and dynamic evolutionary processes in the Tianshan Orogenic Belt and its surrounding areas. Specifically, the characteristics of the high-velocity anomalous structures beneath the Tianshan Orogenic Belt, including the tilt direction, morphology, and location of these structures, are evidence of a unique intracontinental subduction mechanism. Furthermore, the presence of low-velocity anomalous structures in different regions of the belt indicates the existence of small mantle plumes or small-scale mantle convection caused by upwelling thermal material from the asthenosphere as well as partial melting within the crust due to magma underplating. These findings have significant implications for further understanding of the dynamic processes in the Tianshan region, including intracontinental subduction, crustal shortening deformation, lithospheric delamination, and the upwelling of asthenospheric materials. The results also serve as valuable reference data for further study of the seismic activity distribution in the Tianshan area.

     

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