Tracking hydrothermalism in impact craters through rock magnetism on Earth and Mars

Impact cratering is a main geological process in the Solar System that can generate a conspicuous amount of heat and, in wet conditions, potentially favor hydrothermalism.

The latter plays a key role in the mobilization of elements critical for the habitability of a planetary body and, can promote the formation of economic deposits.

Over the last decades, the potential for impact craters to create favorable conditions for life, and the evidence of the past presence of liquid water on the surface of Mars, fed a growing interest in Mars impact craters exploration. Geophysics plays a critical role in the recognition of impact structures, particularly where we lack direct evidences.

Gravity and magnetic observations, as testified by terrestrial impact craters investigations, are primary indicators of these structures and can be used to track physical changes induced by hydrothermal alteration.

On Mars, while impact craters are well preserved, the spatial resolution of the geophysical data is limited by the satellite altitude, therefore the identification of areas of interest for impact-related hydrothermalism is challenging.This project aims to provide a new vector gradient based crustal magnetic model of Mars to better resolve geological features, e.g. hydrothermally altered zones within impact craters.

However, magnetic data interpretation can be ambiguous and requires a solid knowledge of the variables controlling the magnetic properties of altered/unaltered impact craters rocks.

The project aims to accomplish this knowledge with a multi-scale and multidisciplinary study of three selected terrestrial impact craters that experienced hydrothermal alteration.By investigating the magnetic signature of impact craters and by improving the resolution of the global magnetic crustal model of Mars, this project will provide a new tool to investigate the evolution of Mars, and to target areas of interest for future missions where to search for resources and traces of life.