| 东昆仑深部结构地震探测研究现状与展望 |
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| 引用本文：赵荣涛,赵文津,刘志伟,宋洋,陈昌昕.2022.东昆仑深部结构地震探测研究现状与展望[J].地球学报,43(2):189-201. |
| DOI：10.3975/cagsb.2021.022101 |
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| 基金项目:中国地质调查局项目“中国大地构造演化;国际亚洲大地构造图编制”(编号: DD20190367);国家自然科学基金项目(编号: 41674099) |
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| 中文摘要:东昆仑位于青藏高原北部, 是研究青藏高原向北生长的重要地区。该区在印度板块向北俯冲与亚洲阿拉善地块向南挤压下, 新生代构造和地震活动强烈, 是研究青藏高原隆升、构造变形、强震发生机理等问题的极佳试验场。近几十年来, 在东昆仑及邻区开展了大量的地球物理探测, 取得了很多进展, 也存在一些问题。本文通过收集近年来在该研究区开展的人工地震和天然地震探测成果, 综合分析了研究区的壳幔速度结构, 莫霍面形态及各向异性特征, 总结得出以下几点认识: 柴达木盆地南缘上地幔内的北倾界面可能代表早古生代昆仑洋向北俯冲的遗迹; 东昆仑缺乏“山根”, 重力均衡调整对东昆仑莫霍面加深没有起主导作用, 印度板块向北俯冲, 通过青藏高原对柴达木盆地的挤压造成东昆仑地壳垂向增厚。最后我们探讨了东昆仑地区壳幔结构研究的不足, 并对下一步的研究思路和方向进行了展望。 |
| 中文关键词:东昆仑山 深部结构 俯冲遗迹 研究进展 |
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| Status and Prospect of the Seismic Detection of the Deep-seated Structure beneath the East Kunlun Mountains |
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| Abstract:Located in the northern part of the Tibetan Plateau, the East Kunlun Mountains serve as an important area for studying the tectonics of the northward growth of the Tibetan Plateau. Compressed by the northward subduction of the Indian plate and the southward resistance of the Alashan block in Asia, Cenozoic faults and seismicity are widely developed in this area, thus the East Kunlun Mountains are thought to be an excellent site for studying the uplift of the Tibetan Plateau, the structural deformation, and the mechanism of earthquakes. In recent decades, a large number of geophysical explorations have been carried out in East Kunlun and adjacent areas. A lot of progresses have been achieved, although some discrepancies are still existent among the observations by different approaches. Through collection and compiling of the results from active and passive seismic detections carried out in East Kunlun and adjacent areas in recent years, the authors conducted a comprehensively analysis of the crustal and upper-mantle velocity structure, Moho topography and anisotropy features in the study area. The main conclusions drawn can be summarized as follows: The north-dipping mantle interface beneath the southern Qaidam Moho is likely to represent a relic of the Early-Paleozoic subduction zone of the Kunlun Ocean. The lack of deep crustal root beneath the East Kunlun Mountains indicates that the Moho flexuring in the study area was not dominated by isostatic balance. Affected by the far-field stress of the northward subduction of the Indian plate, the crust of the East Kunlun Mountains was mainly thickened by the compression of the India plate (through Tibetan Plateau) exerted on the Qaidam Basin. Finally, the authors discussed the deficiency in the previous studies of the crust-mantle structure research in the East Kunlun Mountains and put forward the reasoning and the direction for future researches. |
| keywords:East Kunlun Mountains deep-seated structure relic subduction research progress |
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