当阳复向斜页岩气探测区地壳结构及其构造暗示  

Crustal structure in the Dangyang Synclinorium shale gas field and its tectonic implications

作　　者：危自根 储日升 谢军 范心甜 WEI ZiGen;CHU RiSheng;XIE Jun;FAN XinTian(State Key Laboratory of Geodesy and Earth’s Dynamics,Innovation Academy for Precision Measurement Science and Technology,Chinese Academy of Sciences,Wuhan 430077,China)

机构地区：[1]中国科学院精密测量科学与技术创新研究院,大地测量与地球动力学国家重点实验室,武汉430077

出　　处：《地球物理学报》2024年第8期2963-2971,共9页Chinese Journal of Geophysics

基　　金：国家自然科学基金(42325401,U20A2095);湖北省自然科学基金(2023AFB1076);中国科学院战略先导科技专项(XDB41020202,XDB18010304)资助。

摘　　要：本文采用接收函数H-κ叠加、多频接收函数和面波联合反演方法,获得了扬子克拉通当阳复向斜区21个密集流动地震台下方的地壳厚度、V_(p)/V_(s)比和S波速度.结果表明,该区平均地壳厚度和V_(p)/V_(s)比值分别为33.8 km和1.75,推测当阳复向斜经历过下地壳减薄但地壳整体尚保持典型克拉通结构特征.研究区绝大部分台站都在3~4 km深度存在1~2 km厚的低S波速度层,推测可能与该深度范围内富集高孔隙度和低密度的页岩气层有关.本研究表明,基于密集流动地震台阵被动源数据资料,可为油气资源勘探提供有价值的参考.In this paper,the crustal thickness,V_(p)/V_(s) ratio and S-wave velocity beneath 21 temporary seismic stations deployed in the Dangyang Synclinorium of the Yangtze Craton were obtained using the H-κ stacking method of receiver function and joint inversion of multifrequency receiver function and surface wave dispersion.An average crustal thickness of 33.8 km and average V_(p)/V_(s) ratio of 1.75 were obtained in the Dangyang Synclinorium,suggesting that it has experienced thinning of the lower crust,but the body of crust still maintains typical cratonic structure.1~2 km-thick low-velocity layer at depths of 3~4 km was imaged beneath most stations,which may be related to the enrichment of shale gas strata with high porosity and low density within the depth range.Our study suggests that passive source data from dense temporary seismic stations can provide valuable references for oil-gas exploration.

关 键 词：当阳复向斜 页岩气勘探 低速薄层 接收函数和面波联合反演 接收函数H-κ叠加 

分 类 号：P315[天文地球—地震学]