SIGNIFICANCE OF THE VARIATIONS IN FLUVIAL INPUT WITHIN JEZERO CRATER FROM PERSEVERANCE ROVER OBSERVATIONS

International audience; The Perseverance rover landed on the floor of Jezero crater on 18 February 2021. The landing site, named “Octavia E. Butler” is located ~2.2 km from the SE-facing erosional scarp of the western fan deposits, which are of strong interest for the mission [1-2]. Images obtained using the Mastcam-Z camera and the Remote Micro-Imager (RMI) of the SuperCam instrument provided the first Mars ground-based observations of this western fan (Fig. 1). At the distance images were taken, the RMI images offer a pixel resolution of 2.2 cm, thus enabling identification of objects of typically 7-8 cm (3-4 pixels). Observations of the residual butte Kodiak confirmed the presence of a lake within Jezero crater, but also showed that the lake deduced from the deltaic architecture at Kodiak had a level ~100 m lower than expected (-2495/-2500 m), and was thus a closed system for a significant period [3]. In addition, the coarser deposits (boulder conglomerates and pebbly sandstones) observed near the top of all of the scarps are typical of fluvial floods with high energy, reflecting a change in hydrology of the fluvial system. Here, we focus on the hydrological characteristics of fluvial deposits observed within the scarps of the delta, both as topsets and as boulder conglomerates.