Mitigating the effects of remanance in magnetic data processing and inversion

Natural remanance will distort the direction of the total magnetization of the magnetic source away from the direction of induction magnetization, which brings difficulties in magnetic data processing and susceptibility inversion. To solve the problem affected by remanance, a magnetic data processing and three-dimensional inversion strategy under remanance conditions is proposed: A method of the total magnetization direction estimation based on multiple correlations is proposed and applied to the processing of magnetic data, which can eliminate the influence of remanance and oblique magnetization. Moreover, the influence of remanance can be considered in the subsequent inversion of magnetic data. Adding the information on the direction of total magnetization into the inversion can more accurately depict the location of the underground magnetic source and recover the physical property distribution. This strategy is applied to the ground magnetic survey data of a mining area in Jiangsu, China. The effects of remanance and oblique magnetization on the processing and inversion of magnetic data are eliminated, and the physical properties and spatial distribution of underground magnetic bodies are restored, which provides geophysical evidence for the study of geological interpretation.