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利用2006年8月到2008年3月北京大学在山西断陷带南部架设的两条东西向流动观测地震台阵记录的远震资料,提取各台站接收函数,然后进行倾斜叠加(Slant stack)和台阵偏移成像,获得了沿台阵横穿山西断陷带的地壳和上地幔的精细结构变化.研究结果显示,山西断陷带下面莫霍面存在明显不连续,莫霍面上隆约4～6 km,纵横波速比从两侧的1.75上升为山西断陷带内部2.0左右,且中、下地壳可能存在一个低速层.山西断陷带的构造模式沿相距140 km的两条剖面表现出明显差异:南端的临汾盆地为拉张作用下的纯剪切模式,向北转化为太原盆地的简单剪切模式.
Based on teleseismic data recorded by two east-west observational seismic arrays erected by Peking University at the south of the Shanxi fault zone between August 2006 and March 2008, the receiver functions at each station were extracted and then subjected to Slant stack. And array offset imaging, the fine structure of the crust and upper mantle beneath the fault array along the platform was obtained.The results show that there is a significant discontinuity in the Moho beneath the Shanxi fault zone, About 4 ~ 6 km, the aspect-ratio velocity ratio increases from 1.75 on both sides to about 2.0 in the Shanxi fault zone, and there may be a low-velocity layer in the middle and lower crust. The tectonic mode of the Shanxi fault zone is along two sections 140 km apart Showing a clear difference: the Linfen basin at the southern tip is a pure shear mode under tension and transforms north into a simple shear mode at the Taiyuan basin.