Application On Forword And Inversion Of Gravity Anomalies With 2D Fault Model

One of the important geological applications of the gravity method is to trace the boundaries of structures across which gravity anomalies and the density contrast differs significantly. We have developed an inversion technique and derived shape parameters of fault structures. We inverted gravity anomalies in profile for distribution of density and the depths to the top and bottom of the fault structure.We used formula of gravity anomalies of a 2D model, computed gravity anomalies with arbitrary angle of the fault plane, depths to the top and bottom of the concealed fault structure. Deal with gravity anomalies and utilizing achievements of senior compared with my method to demonstrate rationalize. We put inversion method-Ridge-regression algorithm to infer the shape parameters of the fault and computed accurately in fitting parameters of the fault structures. In the model of inversion of fault, using respectively four model, theoretical gravity anomaly computed with and without regional background be effected little and parameters were inverted value that is more different in parabolic and constant density profiles. Especially , initial values of misfit function be indicated parabolic density model are found to be more geologically reasonable in comparison with the constant density model. And we analyzed error of the theoretical gravity anomalies model and observed ones. According to datum of senior, error be allowed in the scope.Based on shallow seismic sounding profile combined with drilling, geological, tectonic evolution, drawn the quaternary bearing structural map of four fault basin. Analysed fault structures characteristics and distribution of the active faults combined with the Cenozoic erathem bearing structural map. We dissertated the distribution features of deep faults, the characteristics of shallow fault basement structure, the features of active faults in the basin and the density distribution in yuncheng basin of shanxi province. Using the two density-depth model computed and explained gravity anomalies of the yuncheng basin. Compared with the parabolic and constant density, the interpreted results of a parabolic density model are found to be more geologically reasonable. Curve fitting of theoretical gravity anomalies and observed gravity anomalies, shape parameters convergence of the fault structures, iteration number indicate the reliability of the interpretation.