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通过在青藏高原东北缘设计专门的三维地震观测系统而获得的莫霍界面反射波 ,利用三维反演方法反演重建了该区莫霍 (M)界面的构造形态 ,得到了研究区M界面的三维构造图像和地壳深断裂的展布 .研究区M界面总体上由东北向西南方向呈逐渐下倾趋势 ,而在不同的块体内部又具有不同的倾斜态势 ,反映了不同块体之间的差异和复杂程度的不同 .鄂尔多斯块体M界面变化平缓 ,内部结构完整且坚硬 ;弧形构造区M界面的倾斜趋势发生了逆转 ,此现象可视为该区域在挤压、变形构造作用下M界面发生了明显的扭曲变形 ;秦祁块体M界面呈现出较陡的倾斜趋势 ,在本块东南端与弧形区结合部 ,M界面所显示出的局部隆起可视为地壳发生了强烈扭曲变形的迹象 .综合二维、三维结果认为 ,特殊而复杂的构造变形环境 ,为海原 8 6级大地震的孕育和发生提供了地质条件和深部背景 .
The Moho interface reflection wave obtained by designing a special 3-D seismic observation system on the northeastern margin of the Qinghai-Tibet Plateau is retrieved and reconstructed by the 3-D inversion method. The M-Mo interface structure is reconstructed and the M-interface of this area is obtained Three-dimensional tectonic image and the distribution of deep crustal crust.The M interface of the study area generally shows a downward downward trend from northeast to southwest, and has different inclination in different blocks, reflecting the difference between Difference and complexity.Modal interface of Ordos block changed gently and its internal structure was complete and firm.The inclination of M interface in arc-shaped structure area reversed, which could be regarded as the result of M The interface of Qin Q block shows a steep slope, and the local uplift at the junction of M and the junction of the southeast end of the block with the arc can be considered as a strong distortion of the crust Deformation of the comprehensive two-dimensional, three-dimensional results that the special and complex tectonic deformation environment for the Haiyuan Ms8.6 earthquake genesis and occurrence of geological conditions and deep back .