On the theory of magnetometric resistivity (MMR) methods
On the theory of magnetometric resistivity (MMR) methods
复制标题
磁电阻率（MMR）方法的理论
DOI：
10.1190/1.1440887
复制
发表时间：
1978
期刊：
影响因子：
--
通讯作者：
M. Nabighian
中科院分区：
文献类型：
--
作者：
R. N. Edwards;H. Lee;M. Nabighian
磁电阻率（MMR）方法是基于对与地面中的无感电流相关的低水平、低频磁场的测量。在一个或多个接地电极附近测量磁场的分量。最近，该方法在现场试验中获得成功。本文以统一的格式介绍了该方法的理论基础。部分材料来自难以获得的有价值的已发表论文。本文的其余部分包含了未发表的原始理论结果，它表明，水平层状地球不产生磁电阻异常。详细介绍了各向异性地球、垂直和倾斜接触、薄岩脉和厚岩脉、半圆柱形和半球形凹陷以及α介质的特征异常，指出影响MMR异常的两个因素：几何形状和电导率对比度。对于许多模型，可以将这两种效应分开。典型曲线是非常大的电导率对比，以说明几何形状的影响。辅助曲线使有限的电导率对比从现场数据推导出来。
The Magnetometric Resistivity (MMR) method is based on the measurement of the low-level, low-frequency magnetic fields associated with noninductive current flow in the ground. A component of the magnetic field is measured in the vicinity of one or more grounded electrodes. Recently, the method was tested successfully in the field.The present paper presents the theoretical basis of the method in a unified format. Part of the material is derived from valuable published papers which are difficult to obtain. The remainder of the paper contains original unpublished theoretical results.It is shown that a horizontally layered earth yields no MMR anomaly. The characteristic anomalies for an anisotropic earth, vertical and dipping contacts, thin and thick dikes, and semicylindrical and hemispherical depressions, as well as alpha media are presented in detail.There are two factors which influence the MMR anomaly; geometry and conductivity contrast. For many models, it is possible to separate these two effects. Type curves are presented for very large conductivity contrasts to illustrate the effect of geometry only. Ancillary curves enable finite conductivity contrasts to be deduced from field data.