Mixed sediments often occur in continental lake basins due to the coupling effects of the climate, hydrodynamic conditions, tectonic processes, and material abundances of provenances, and the mixed sedimentary rock formed in this process has dual characteristics. The response of mixed sedimentary rock to seismic waves is different from that of conventional sandstones or carbonate rocks and easily causes errors in identification and characterization by conventional research methods. In this paper, taking the mixed sedimentary rock in the southern part of the Laizhouwan Sag in the Bohaiwan Basin as an example, the petrological characteristics of the mixed sedimentary rock are studied and its sedimentary model is established. On this basis, a comparative study of the seismic waveform characteristics is carried out. Compared with sandstone, the waveform continuity of mixed sedimentary rock is poor, the amplitudes are weak and the frequencies are low, but opposite results are found compared with the conglomerate formed by gravity flow at the bottom. Contrast analysis of the acoustic impedance shows that the value of the acoustic impedance of mixed sedimentary rocks is higher than that of sandstone and is generally greater than 6.2 × 10 6 kg/m 3 m/s. Therefore, the threshold value between sandstone and mixed rock is set to 6 × 10 6 kg/m 3 m/s in inversions to delineate the boundary between mixed sedimentary rock and sandstone. Finally, using seismic attribute analysis and inversion technology, the scales of the horizontal and vertical distributions of the mixed sedimentary rock platform are predicted. The range of the platform is 7100 m in length, 3100 m in width, and 15.6 km 2 in area. Longitudinally, the mixed sedimentary rock layer spans the third layer of the third member of Shahejie Formation (ES 3 3 ).

中文翻译：

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渤海湾盆地硅质-碳酸盐岩混合沉积岩地震识别与定量表征

由于气候、水动力条件、构造过程和物源物质丰度等因素的耦合作用，陆相湖盆经常出现混合沉积物，在这一过程中形成的混合沉积岩具有双重特征。混合沉积岩对地震波的响应不同于常规砂岩或碳酸盐岩，容易造成常规研究方法识别和表征的错误。本文以渤海湾盆地莱州湾凹陷南部的混合沉积岩为例，对混合沉积岩的岩石学特征进行了研究，并建立了沉积模型。在此基础上，对地震波形特征进行了对比研究。与砂岩相比，混合沉积岩的波形连续性差，振幅弱，频率低，但与底部重力流形成的砾岩相比，结果相反。声阻抗对比分析表明，混合沉积岩的声阻抗值高于砂岩，一般大于6.2×10 6 kg/m 3 m/s。因此，反演中砂岩和混合岩之间的阈值设置为6×10 6 kg/m 3 m/s，以划定混合沉积岩和砂岩之间的边界。最后，利用地震属性分析和反演技术，预测了混合沉积岩台地水平和垂直分布的尺度。平台的范围为长7100 m，宽3100 m，15。6 公里 2 的面积。纵向上，混合沉积岩层跨越沙河街组三段第三层（ES 3 3 ）。