• ISSN 2097-1893
  • CN 10-1855/P
邓阳凡,罗恒,张周,朱晟,黄润青,胡仲发,李鑫. 2024. 地球陨石坑地球物理探测研究进展. 地球与行星物理论评(中英文),55(2):153-163. DOI: 10.19975/j.dqyxx.2023-027
引用本文: 邓阳凡,罗恒,张周,朱晟,黄润青,胡仲发,李鑫. 2024. 地球陨石坑地球物理探测研究进展. 地球与行星物理论评(中英文),55(2):153-163. DOI: 10.19975/j.dqyxx.2023-027
Deng Y F, Luo H, Zhang Z, Zhu S, Huang R Q, Hu Z F, Li X. 2024. Recent progress of geophysical exploration in Earth's impact craters. Reviews of Geophysics and Planetary Physics, 55(2): 153-163 (in Chinese). DOI: 10.19975/j.dqyxx.2023-027
Citation: Deng Y F, Luo H, Zhang Z, Zhu S, Huang R Q, Hu Z F, Li X. 2024. Recent progress of geophysical exploration in Earth's impact craters. Reviews of Geophysics and Planetary Physics, 55(2): 153-163 (in Chinese). DOI: 10.19975/j.dqyxx.2023-027

地球陨石坑地球物理探测研究进展

Recent progress of geophysical exploration in Earth's impact craters

  • 摘要: 地球物理探测在研究和发现撞击构造方面发挥着重要作用. 本文综述了地球陨石坑的重、磁、电、震等常见地球物理特征. 陨石坑最明显的地球物理特征是圆形或环形的负重力异常,其主要原因是岩石破裂和角砾化导致岩石密度降低;具有较低的磁异常,细节特征复杂,其主要原因是撞击熔融降低了陨石坑内部岩石的磁化率,陨石撞击后的改造则造成了复杂的细节特征;简单陨石坑具有较高的电导率,复杂陨石坑具有从中央隆起向周缘升高的电导率,其受控于岩石的破碎程度和上覆沉积层的含水量,破碎程度、含水量越高电导率越高;具有低的地震波速,主要原因是破碎的角砾岩和断裂具有相对原岩更低的波速. 此外,地震反射波探测发现陨石坑撞击构造有明显凹形特征. 国际上已开展了大量陨石坑的地球物理探测研究,而我国现有被发现且证实的陨石坑不仅数量稀少,其相关的地球物理探测研究更是不多见. 通过对国内外陨石坑的常见地球物理特征开展综述和总结,不仅可为我国发现更多潜在的陨石坑提供科学参考和依据,同时也为公众认识和了解撞击构造提供可靠的科普素材,进而有效拓展地球陨石坑的科研和人文价值.

     

    Abstract:
    Geophysical exploration plays an important role in detecting and studying impact structures. This article reviews the common geophysical features of Earth's impact craters, including their gravity, magnetic, electrical, and seismic characteristics. The most obvious geophysical feature of impact craters is the circular or ring-shaped negative gravity anomaly, which is mainly caused by rock fracture and brecciation resulting in lower rock density. Low magnetic anomalies with complex details are mainly due to impact melting reducing the magnetic susceptibility of rocks inside the crater and post-impact modification resulting in complex detailed features. High electrical conductivity is found in simple craters, while more complex craters have gradually increasing electrical conductivity from the central uplift to the marginal rim. The conductivity is dominated by the fracture extent and water content. Low seismic velocity is mainly due to the lower velocity of fractured breccia and fractures relative to the original rock. In addition, seismic reflection profiling has found that impact structures have distinct concave shapes.
    Internationally, there are abundant research on the geophysical exploration of impact craters. However, in China, confirmed impact craters are rare in number and lack related geophysical exploration. Summarizing the common geophysical characteristics of impact craters provides a basis for geophysical exploration of potential impact crater regions in China and offers material for popular science and public engagement purposes.
    There are two confirmed impact craters in China, the Xiuyan crater in Liaoning Province and the Yilan crater in Heilongjiang Province. Active seismic investigations had been conducted in Xiuyan crater, and revealed its relative velocity and attenuation structure. However, although several geological studies have been conducted, a comprehensive geophysical study of the newly discovered Yilan crater is still lacking. Recently, our group has conducted dense seismic nodes and distributed acoustic sensing in Yilan crater, the results of which will be reported in the near future.

     

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