NASA's Perseverance rover has uncovered a complex geological history in the "Margin Unit" region of Jezero Crater on Mars: analysis shows the area was shaped by groundwater, an ancient lake and hydrothermal activity, according to infohub.kz.
The findings, published in the journal Communications Earth & Environment, overturned the initial hypothesis that the site consisted of sedimentary rocks from the shoreline of an ancient lake. Instead, the rover encountered igneous rocks that formed deep within the planet and later reached the surface.
Using the SuperCam instrument under the leadership of lead author Candice Bedford of Purdue University, scientists analyzed the chemical composition of more than 185 rock targets. The research showed that the olivine-rich igneous rocks were exposed to water at least three times.
The first episode involved carbon dioxide-rich groundwater, whose reaction produced carbonates. The second correlates with the existence of a lake in Jezero Crater, which left behind traces of silica. The third was caused by the circulation of hot subsurface water: in the eastern part of the region, the rover found 25-centimeter-thick veins containing the minerals fluorite and calcium sulfate.
According to co-author Eleni Ravanis of the University of Hawaii at Manoa, the combination of carbonates, silica and hydrothermal activity makes this region critically important for studying Mars' ancient habitability and searching for biosignatures.