Alteration history of Séítah formation rocks inferred by PIXL x-ray fluorescence, x-ray diffraction, and multispectral imaging on Mars

Abstract

Here, we demonstrate that diffracted and fluoresced x-rays detected by the PIXL instrument (an x-ray fluorescence microscope on the Perseverance rover) provide information about the presence or absence of coherent crystalline domains in various minerals. X-ray analysis and multispectral imaging of rocks from the Séítah formation on the floor of Jezero crater shows that they were emplaced as coarsely crystalline igneous phases. Olivine grains were then partially dissolved and filled by finely crystalline or amorphous secondary silicate, carbonate, sulfate, and chloride/oxychlorine minerals.