三维地质模型的CSAMT模拟研究

CSAMT simulation of three-dimensional geological model

应用CSAMT方法进行标量测量时,一般要求测线沿垂直构造走向的方向布测.在实际测量的时候由于地表条件复杂经常出现无法判断地下构造走向的情况,例如,在长白山地区进行CSAMT测量,由于表面覆盖有玄武岩无法判断地下构造走向,对得到的标量数据进行一维、二维反演处理时无法判断哪种反演方式的结果更准确.鉴于此,建立三维地质模型,应用CSAMT三维正演程序进行数值模拟.研究测线与构造走向平行,呈45°及垂直三种情况下的一维、二维反演,对结果做比较分析.实验结果表明,测线平行构造走向时,一维、二维反演结果近似;测线与构造走向呈45°或垂直时,二维反演结果比一维反演结果对异常体的形状,大小,埋深及电性参数反演的更准确.

Applications CSAMT method scalar measurements,general requirements for measurement along the survey line perpendicular to structural trend direction. In actual measurement time due to complex surface conditions can not determine the direction of the underground structure is often the case. For example,in the Changbai Mountain region CSAMT measure,since the surface is covered with basalt unable to determine subsurface structure,which inversion mode can not be judged on the scalar data obtained by one-dimensional, two-dimensional inversion processing is more accurate results. Therefore,the establishment of three-dimensional geological model, applications CSAMT dimensional numerical simulation program forward. Research survey line and parallel structural trends,was 45° and one-dimensional,two-dimensional inversion vertical three cases,do a comparative analysis of the results. Experimental results show,when the survey line parallel structural trends, one-dimensional, two-dimensional inversion results approximate; when structural trends survey line was45° or perpendicular,two-dimensional inversion results than the one-dimensional inversion results of shape, size, depth and electrical parameters inversion anomalous body is more accurate.