Magnetic Lineations in the Ancient Crust of Mars

TLDR

Mars’ ancient crust shows east‑west magnetic lineations similar to Earth’s seafloor spreading features, suggesting a possible relic of past plate tectonics. The Mars Global Surveyor, in a highly elliptical polar orbit, collected vector magnetic field data above Mars at altitudes exceeding 100 km. The data reveal that ancient, heavily cratered highlands possess strong crustal magnetization organized into east‑west‑trending linear features up to 2000 km long, exceeding Earth’s crustal values by more than an order of magnitude and displaying alternating polarity.

Abstract

The Mars Global Surveyor spacecraft, in a highly elliptical polar orbit, obtained vector magnetic field measurements above the surface of Mars (altitudes >100 kilometers). Crustal magnetization, mainly confined to the most ancient, heavily cratered martian highlands, is frequently organized in east-west-trending linear features, the longest extending over 2000 kilometers. Crustal remanent magnetization exceeds that of terrestrial crust by more than an order of magnitude. Groups of quasi-parallel linear features of alternating magnetic polarity were found. They are reminiscent of similar magnetic features associated with sea floor spreading and crustal genesis on Earth but with a much larger spatial scale. They may be a relic of an era of plate tectonics on Mars.