An automated method for the interpretation of magnetic vertical-gradient anomalies

Abstract The use of airborne magnetic vertical-gradient surveys is increasing. Interpretation, however, is mostly used qualitatively as an aid to geologic mapping. Presently, quantitative interpretation techniques are based on the analysis of isolated anomalies. In this paper, we develop a numerical method for interpreting the magnetic vertical-gradient anomalies of dipping dikes and planar geologic contacts. The method is based on a linearization of the equations describing these anomalies. The solution can be used to interpret isolated anomalies or whole profiles in a Werner-style deconvolution.Using data from the Val d'Or mining area (Canada), we have calculated magnetic models to test the interpretation technique. Magnetic vertical-gradient profiles calculated from the interpreted models closely match the observed data.