Magnetic lineations in the southern strong magnetic anomalies and their possible causes

The Martian crustal magnetic field exhibits a hemispheric dichotomy, with the magnetic field in the southern highlands being significantly stronger than that in the northern lowlands, and it presents a banded feature of alternating polarity reversal on a global scale. Various alternative theories have been proposed to explain the formation of magnetic lineations, including seafloor spreading, dike intrusion, hot spot tracking, mantle convection, discrete source merging, etc. In this study, by analyzing the magnetic field and crustal thickness, it was found that in some regions of the southern highlands, the crustal thickness is correlated with the magnetic field, and the correlation is relatively high in specific areas. Forward modeling was used to investigate the effect of magnetization layer thickness variations on the magnetic lineations. The results indicate that when the thickness difference of the magnetization layer exceeds a certain value, strip-shaped magnetic anomaly features can be observed at satellite altitudes of several hundred kilometers. Although Mars has experienced various geological activities and demagnetization processes, variations in crustal thickness may be responsible for magnetic lineations in the southern strong magnetic anomalies.