MAPPING THE DISTRIBUTION OF POTENTIAL LACUSTRINE DEPOSITS ACROSS THE FLOOR OF EBERSWALDE CRATER

Eberswalde Crater is one of eight proposed landing sites for the Mars 2020 rover mission. The primary exploration target within Eberswalde Crater is the delta dominating the Western portion of the crater floor. Lacustrine deposits would also be regions of interest for potential biosignature concentration and preservation, but extensive lacustrine sediments beyond the prodelta have not been identified in previous studies. However, many isolated hills and mesas cover the basin floor, some of which may be the erosional remnants of formerly extensive lacustrine deposits. This study aims to identify candidate lacustrine outcrops among these mesas and hills and to map their distribution across the Eberswalde crater floor. Using HiRISE imagery, we have defined a classification system for mesas and hills within Eberswalde Crater, based on surface texture, albedo, erosional resistance, and overall geometry. We have mapped each hill and mesa larger than ~25 meters within the Mars 2020 landing ellipse and have assigned them to one of six geomorphologic classes. Of these classes, the polygonally fractured hills and mesas are the strongest candidates for lacustrine deposits exposed basinward of prodelta deposits, as they have similar light-toned albedos and weathering expressions as the Eberswalde delta bottomset deposits. These polygonally fractured outcrops have been identified throughout the landing ellipse in varying abundance, and are compelling targets for exploration if Eberswalde Crater is selected as the Mars 2020 landing site. Future work will use CRISM observations from the Eberswalde crater floor to constrain the mineralogy of the potential lacustrine deposits, and will explore the spatial relationship of the hills and mesas in the Eberswalde crater to other units and geomorphic features within the crater.