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利用布置在鄂尔多斯东南缘地区的地震台阵记录的远震资料数据,采用接收函数方法研究这一地区的地壳厚度和地壳结构.研究结果显示,各台站下方的Moho震相可以被清楚地识别,Moho深度向东南方向逐渐变浅,从鄂尔多斯块体内部的43km一直减小到邻近秦岭北缘的30km左右.地壳结构和Moho形态特征在横向上表现出明显的差异性,在研究区可以分为4个部分:(Ⅰ)在鄂尔多斯块体内部,Moho平缓连续,深度在40km左右,具有稳定克拉通地壳的特征;(Ⅱ)渭河-山西地堑,Moho出现上隆,上隆幅度3km左右,地壳减薄,可能是由上地幔物质上涌引起的;(Ⅲ)熊耳-伏牛山地区,Moho平缓连续,深度在36～33km之间,往东南方向逐渐变浅,地壳结构相对简单;(Ⅳ)邻近秦岭北缘的的河淮盆地,Moho呈现出强烈的不连续特征,横向结构差异明显,平均深度约31km.另外,位于构造边界的两个台站(st11和st18)的下方,Moho呈现明显的不连续现象,可能受到边界断裂的影响.研究结果表明鄂尔多斯东南缘地区地壳结构在横向上有很大的差异和变化,对研究鄂尔多斯东南缘地区不同块体间的相互关系具有重要的意义.
Using the teleseismic data recorded by the seismic array in the southeastern margin of Ordos, the receiver function method is used to study the crustal thickness and crustal structure in this area. The results show that the Moho seismic phase below each station can be clearly identified , The Moho depth gradually becomes shallower in the southeast direction and decreases from 43km in the Ordos block to 30km near the northern margin of the Qinling Mountains.The crustal structure and Moho morphological characteristics show obvious differences in the horizontal direction and can be divided into two types in the study area (4): (Ⅰ) In the Ordos block, Moho is flat and continuous with a depth of about 40km and has the characteristics of stable craton crust; (Ⅱ) Moho appears to be upwelling in the Weihe-Shanxi graben, and the uplift amplitude is about 3km (Ⅲ) Xiong’er-Funiu Mountain area, Moho is gentle and continuous with a depth of 36 ~ 33km and gradually becomes shallow in the southeast direction, and the crustal structure is relatively simple. ( Ⅳ) In the Huaihe Basin, adjacent to the northern margin of Qinling Mountains, Moho shows a strong discontinuity with obvious lateral structure with an average depth of about 31 km. In addition, below the two stations (st11 and st18) Was presented The obvious discontinuities may be affected by the boundary faults.The results show that the crustal structures in the southeastern margin of Ordos have great differences and changes in the horizontal direction and are important for the study of the interdependence of different blocks in the southeastern margin of Ordos significance.