The Effect of Remanent Magnetization on Aeromagnetic Interpretation

Abstract

The interpretation of aeromagnetic maps when the source may be approximated to a point dipole or line of dipoles is considered for the general case in which the dipole moment is not necessarily parallel to the Earth's magnetic field. For the line of dipoles, it is shown that even in this general case the depth and location of the source can be found, and in addition the direction of the component of the dipole moment in a plane normal to the line source may be determined. If the Königsberger ratio for the rock constituting the source is large, this is approximately the direction of the remanent magnetization. Such information is important from a palaeomagnetic viewpoint. When the source approximates closely to a point dipole, it is not possible both to locate the source and determine the direction of the dipole moment from an analysis of the aeromagnetic map and the solution of the problem requires further information.