基于主轴各向异性介质的三维张量CSAMT正演模拟  

3D tensor CSAMT modeling based on axis anisotropic media

作　　者：刘晓 汪茂[2,3] 陈炳贵 LIU Xiao;WANG Mao;CHEN BingGui(School of Water Conservancy and Ecological Engineering,Nanchang Institute of Technology,Nanchang 330099,China;China University of Geosciences,Beijing 100083,China;Key Laboratory of Geo-detection(China University of Geosciences,Beijing),Beijing 100083,China)

机构地区：[1]南昌工程学院水利与生态工程学院,南昌330099 [2]中国地质大学(北京),北京100083 [3]地下信息探测技术与仪器教育部重点实验室,北京100083

出　　处：《地球物理学进展》2021年第3期1095-1102,共8页Progress in Geophysics

基　　金：江西省教育厅科技项目(GJJ171006)资助。

摘　　要：在地质情况复杂化以及地质勘探精细化的要求下,有必要开展张量CSAMT正反演研究.考虑到各向异性对正反演结果影响较大,本文开展基于主轴各向异性介质的张量CSAMT正演研究.根据含源的电场控制方程,引入主轴各向异性介质的张量电阻率,将电场总场分解为一次场和二次场,一次场由Key的算法得到,二次场利用有限差分法计算,即实现了主轴各向异性介质的张量CSAMT三维正演.通过与二维有限元算法结果比较来验证算法的正确性;通过设计几组主轴各向异性三维模型,分析卡尼亚电阻率和相位的响应特征.结果表明卡尼亚电阻率ρxy和ρyx分别对异常体X方向和Y方向的电阻率变化敏感,说明张量CSAMT方法对识别各向异性具有优势.本研究为开展任意各向异性介质的张量CSAMT正反演研究提供基础.It is necessary to carry out the research of tensor CSAMT modeling and inversion under the requirements of complex geological conditions and refined geological exploration. Considering that anisotropy has great influence on modeling and inverse results. In this paper, we realize tensor CSAMT modeling based on axis anisotropic media. According to the control equation of electric field with sources, the tensor resistivity of axis anisotropic medium is introduced. The total electric field is decomposed into primary field and secondary field, the primary field is obtained by Key algorithm, and the secondary field is calculated by Finite Difference Method(FDM), which realizes the tensor CSAMT three-dimensional modeling of axis anisotropic medium. The correctness of the algorithm is verified by comparing with the results of two-dimensional Finite Element Method(FEM), and the response characteristics of Carnia resistivity and phase are analyzed by designing several groups of axis anisotropy three-dimensional models. The results show that Cania resistivity ρxyand ρyx are sensitive to the change of resistivity in X direction and Y direction respectively, which indicates that tensor CSAMT method has advantages in identifying anisotropy. This study provides a basis for forward and inverse study of tensor CSAMT in arbitrary anisotropic media.

关 键 词：张量CSAMT 主轴各向异性介质 三维正演 

分 类 号：P631[天文地球—地质矿产勘探]