变密度常磁化强度界面重磁联合反演

Joint Inversion of Gravity and Magnetic Data with Varying Density and Constant Magnetic Susceptibility Interface Model

摘要:

大多数沉积盆地的地层密度随着深度的增加而加大，基底界面反演时因而要考虑到密度差也随界面深度发生变化.当基底岩石同时也具有磁性，可通过重磁联合反演来揭示沉积盆地基底埋深这一重要的构造信息，尽量减少重、磁异常反演的多解性.针对变密度和常磁化率界面，采用迭代联合反演的方法，利用阻尼最小二乘法和重磁力Parker正演公式一级近似求取界面深度的修正量，来反演目标界面的起伏.模型试验表明这一方法行之有效.将此方法用于实际资料处理，取得了较好效果.

Abstract:

The fact that the density contrast varies with the depth should be considered when inversing the interface of basement,for the density of the layer becomes larger with depth in most sedimentary basins.When the basement rock also posses magnetism， joint inversion of gravity and magnetic data can be used to reveal the burial depth of sedimentary basins,which is one of the most important structure information,so nonuniqueness of inversion can be reduced.Iterative method is used in the model of varying density and constant magnetic susceptibility to inverse the fluctuation of the interface,and to get the correct of interface depth through damped least squares method and first order of Parker’s Equation of gravity and magnetic.Feasibility is proved through model test,and this method is applied to the process of field data,good effects are achieved.