What geological information involved with the remanent magnetization can be extracted from the magnetic anomaly?

Abstract

Natural remanent magnetization (NRM) is the part of rock magnetism, which leads to more complex magnetic data inversion and interpretation. The conventional inversion methods focus on reducing the influence of the remanent magnetization and recovering the depth and shape of magnetic sources, while the remanent magnetization is an important parameter to understand the mineralization /geological process. The remanent magnetization can not only reflect the geological structure and mineral composition, but also contain the geomagnetic field record of each geological period. We study to obtain the geological information involved with the remanent magnetization. In the case of Daye iron-ore deposit in Hubei province, we calculate the direction and intensity of remanent magnetization based on the prior information of Königbergs ratio, the direction and intensity of the total magnetization. In the Yeshan region, we use the IDQ curve to estimate the direction of the remanent magnetization. The results show that the remanent magnetization direction, extracted from magnetic anomaly, can not only indicate the information of local geological activities, but also be used to classify the lithologies of the sub-anomalies.