Mineral composition of Al-rich float rocks in Jezero crater as seen by Super-Cam

During its traverse across the Jezero crater floor and western fan, the Perseverance rover encountered > 4000 float rocks – of variable size (up to ~ 50 cm) scattered on the ground without apparent connection to the surrounding stratigraphy [1]. Analysis performed using the SuperCam instrument’s [2,3,4], Laser Induced Breakdown Spectroscopy (LIBS) revealed a high concentration of Al2O3, Cr, Ti and Ni [5], and very low of Fe, Mg, Ca and Na [5, 1]. SuperCam’s infrared reflectance spectroscopy (IRS, between 1.3 and 2.6 μm) showed the presence of Al-rich aqueous alteration minerals (characteristic absorption bands of kaolinite and Al-smectites at 1.4 and 2.2 μm) as well as some (likely Cr-) spinels, identified uthrough their broad asymmetric 2 μm band, responsible for the concavity of IR spectra. These mineral species alone do not fully account for the spectral shapes; hence, the objective is to further investigate spectral modeling to determine the most probable mineral assemblages. Here, we present the results of modeling 17 light-toned float rocks, up to Sol 924, complementary to [1].