GEOLOGIC MAPPING AND STRATIGRAPHIC ANALYSIS OF A CANDIDATE MARS 2020 LANDING SITE: JEZERO CRATER, MARS

Jezero crater is an ~45 km diameter impact crater located in the Nilli Fossae region of Mars that contains delta deposits interpreted to represent an ancient open-basin paleolake fed by two large inlet valleys connected to an extensive watershed and drained by an outlet valley. Jezero is under consideration as one of three final landing sites for the Mars2020 rover mission, whose objectives include collecting and caching samples from an astrobiologically relevant, geologically diverse site for return to Earth by possible future missions.

Previous mapping efforts focused in Jezero crater used images from the Mars Reconnaissance Orbiter (MRO) Context Camera (CTX) to map at a scale of ~1:30,000 [1]. This study uses ~25 cm/pixel images from the High Resolution Imaging Science Experiment (HiRISE) to construct an orbital geologic map of the Jezero landing ellipse at a scale of 1:5,000. The orbital geologic map and geologic cross-sections presented here provide additional insight into the spatial and temporal distribution of sedimentary and potentially volcanic units likely to be encountered by the Mars2020 rover, should it land in Jezero crater. We report the identification of additional raised features that may be delta remnants located 3.3 km southeast from existing mapped delta remnants [1], and more than 6 km southeast from the present-day extent of the contiguous western fan deposit. The mapped distribution of these deposits could suggest that the Jezero delta system was once much more expansive than observed today, and enables facies-based predictions for distal deposits that could be explored by the M2020 rover throughout the ellipse. We also map additional subdivisions of the crater floor units, providing a more accurate assessment of the distribution of bedrock versus surficial regolith and modern-day eolian deposits within the Mars2020 landing ellipse. The map constructed here is used to identify regions of interest within the Jezero ellipse and to assist in preliminary traverse planning of the western delta front, crater floor units, and delta remnants.

[1] Goudge et al. (2015). Assessing the mineralogy of the watershed and fan deposits of the Jezero crater paleolake system, Mars. Journal of Geophysical Research: Planets, 120(4), 775-808.