Estimating remanent magnetization of Matachewan and Sudbury mafic dikes in the Abitibi greenstone belt from aeromagnetic data Available to Purchase

Magnetic surveys involve measuring the response of the total magnetization in rocks. Total magnetization is the vector sum of induced and remanent magnetization. It is common to overlook remanence and assume induced magnetization is dominant during interpretation and modeling. This case study estimates remanence directions of ten mafic dike anomalies in the Abitibi greenstone belt from aeromagnetic data using a magnetization vector inversion and statistical magnetic susceptibility data methodology. The average remanent magnetization is separated from total magnetization vector inversion models by assuming a magnetic susceptibility distribution. Despite a wide range of estimated remanent magnetization directions, the results provide insights for geological interpretation. Eight anomalies exhibit significant remanence in different directions from the inducing field, some aligning with average paleomagnetic directions. However, the study emphasizes the inherent ambiguity and non-uniqueness of the remanence estimation methodology, presenting challenges even for isolated, compact, and steeply dipping sources.