Correlations between the Crustal Field and the Magnetization Layer’s Geometry in the Martian Magnetic Lineation Area

Abstract Magnetic lineations on Mars, the remanent magnetization presents east–west-trending banded features, were suggested to be associated with seafloor spreading, dike intrusion, hot spot tracking, mantle convection, discrete source merging, etc. However, a missing link remains between the magnetization layer’s geometry, controlled by these processes, and the scale and magnitude of magnetic signals in the satellite orbit. Combining the magnetic field anomalies with the geometry of the crust, we find high correlations between the polarity of the radial field and the crustal thickness in the Martian southern highlands. Forward modeling is also used to reproduce the magnetic lineations based on the magnetization layer with a nonuniform thickness in a 25 km crust. The forward modeling results show lateral variation in the radial field ranges 10∼40 nT per degree, comparable to the result from the spherical harmonic model based on satellite data. Our study suggests the mantle plume upwelling causes the nonuniformity in the magnetization layer, producing strip-shaped magnetic anomalies with periodic polarity reversals.