P.Y Meslin1, E. M. Hausrath2, E. Cardarelli3, J. Lasue1, O. Forni1, O. Beyssac4, L. C. Kah5, L. Mandon6, O. Gasnault1, E. Dehouck7, F. Poulet8, C. Quantin-Nataf7, P. Pilleri1, P. Gasda9, S. Schröder10, R. Wiens9, S. Maurice1 and the SuperCam science team. 1IRAP, Toulouse, France (acousin@irap.omp.eu), 2Dept. of Geoscience, UNLV, NV, USA, 3NASA JPL, CA, USA,5Dept of Earth and Planetary Sciences, UTK, TN, USA. 4IMPMC, Paris, France. 6LESIA, Meudon, France. 7LGL-TPE, Lyon, France. 8IAS, Orsay, France. 9LANL, NM, USA.10DLR, Berlin, Germany. Introduction: Soils correspond to loose, unconsolidated materials resulting from the physical and chemical alteration of rocks by several processes [1-3]. Soils are interesting because they can be used to estimate the bulk composition of the crust by looking at their primary constituents[2], but they also bring important clues concerning the past environmental conditions on Mars as they are known to contain some secondary phases. Orbital data have shown that dust and soils are hydrated (4 ±1 wt%) and relatively homogeneous all over the planet [4]. Soil analyses performed with Viking, Pathfinder and the MER rovers have confirmed this [5]. The Mars Science Laboratory mission with the Curiosity rover showed that fine-grained soils at Gale crater contain up to 3 wt % H2O [6,7], and that this hydration is carried mainly by the X-ray amorphous component [8]. ChemCam observations showed that fine-grained soils are more hydrated than the coarser ones [1, 9], probably due to the amorphous component [10,11], that seems to contain some hydrated Mg sulfates [10]. The Perseverance rover landed at a new location, Jezero crater, in February 2021. Onboard Perseverance, the SuperCam instrument uses the same LIBS technique as ChemCam, which allows direct comparison between soils from Gale and Jezero. Objectives: This study aims at comparing soils encountered at Jezero crater with those from Gale, analyzed with the LIBS technique, first to investigate the hypothesis of a local component in the coarser grains, and to investigate the homogeneity of the fine-grained soils over the planet. Methodology: This study uses data from the ChemCam and SuperCam instruments. Only soil targets have been considered, but no distinction has been made between loose soils and soil crusts [12]. The ChemCam soil targets come from [13], where targets were classified up to sol 3007. The same visual classification has been performed using the SuperCam data. At Gale crater it was shown that there were no major differences in composition between fine (125-250 μm) and medium-grained (250-500 μm) sizes [12]. Therefore, soils from Jezero have been classified using only three categories: fines and medium-grained size (<500 μm), coarse-grained (0.5-1mm) and very coarse-grained size (12mm). Results: As of sol 236, only 128 points (over 1130 points) have sampled a soil target with SuperCam/LIBS in Cf-fr and South Seitah. From the visual classification, 54 % of them correspond to fine/medium -grained soils, 5 % correspond to coarse-grained soils, 39 % correspond to very coarsegrained, and only 2 % to granules (> 2mm). As there are only a few points on granules and coarsegrained soils, the study will mainly use the fine/medium and the very coarse-grained soils. Fig. 1 shows the distribution of major elements between the fine/mediumand very coarse-grained soils. Some differences can be observed: fine/medium-sized soils have more points enriched in Al2O3, CaO and alkali, whereas very coarse-grained soils have more points enriched in FeO and MgO, and some low values in SiO2. There is a bimodal distribution for MgO that is observed in soils for all grain sizes, but there are more very coarse-grained soils enriched in MgO: this is probably due to the fact that larger grains are enriched in olivine [14,15]. This is also consistent with MnO content as shown in [16]. IR spectroscopy of soils has also revealed that the coarser ones are enriched in olivine and pyroxenes sometimes associated with alteration phases such as Mg-rich phyllosilicates, while the fine-grained soils are more mafic with a low abundance of olivine, as seen from orbit. Overall, very-coarse-grained soils show a wide dispersion in MgO content, as well as in alkali, Al2O3, CaO and SiO2. This could reflect the presence of other phases, such as feldspars and non-silicates (some points enriched in MgO are lower in SiO2, but shot-to-shot data need to be investigated).