Morphology, Morphometry and Distribution of Isolated Landforms in Southern Chryse Planitia, Mars

Abstract

Oxia Planum, the landing site of the ExoMars 2022 rover "Rosalind Franklin", is a clay-rich plain located on the boundary between the ancient, rugged terrain of Arabia Terra (Quantin-Nataf et al., 2021), and the young, smooth plains of Chryse Planitia. Distributed across the Oxia Planum and wider Circum-Chryse region are thousands of kilometer-scale isolated landforms that resemble terrestrial mesas, buttes, hills, and plateaus (Figure 1). The mounds are conspicuous features that can be distinguished by their positive relief, high albedo, and low thermal inertia relative to the surrounding plains. As a widespread geomorphological feature in this highland-lowland transitional area, they are an important component of the geological history of the region, but their morphological variations, origins, and ages were hitherto not well understood. Importantly, several of these mounds are found within the landing ellipse of the ExoMars rover

Rivers and Lakes in Western Arabia Terra: The Fluvial Catchment of the ExoMars 2022 rover landing site

“…Sinuous ridges are found in areas with 'inverted' crater fills and eroded remnant mounds (McNeil et al, 2021). This suggests that substantial burial and erosion has occurred.…”

“…Sinuous ridges are also associated with light toned fractured terrains. Sinuous ridges exhibit branching patterns (Figure 6e), as well as a variety of surface textures, and are overlain by the regionally significant rounded buttes (Figures 6e) part of a significant regional population (McNeil et al, 2021).…”

“…We attribute the variation in occurrence to regional variations in exhumation processes and degree of erosion. To the north-west of the catchment where there has been the most erosion, sinuous ridges predate the formation of the rounded buttes (Figure 6e) which are likely to have been part of a regionally extensive layer (McNeil et al, 2021). This means the material of the ridges (i.e.…”

“…Inverted or exhumed channels in the west of the catchment support an alluvial landscape (Figure 6), but this may only represent what post Noachian denudation (McNeil et al, 2021) has exposed and a grater range of environments contributing to infilling the Oxia Basin are represented in the stratigraphic record. Additionally the groundwater table would have been high and thus actively modifying (secondary) mineralogy.…”

Rivers and Lakes in Western Arabia Terra: The Fluvial Catchment of the ExoMars 2022 Rover Landing Site

“…Here (d) the plains subjacent of sinuous ridges transition into valley or low‐relief channel, the sinuous ridges have different texture on their top surface. (e) Branching sinuous ridges are overlain by rounded buttes (McNeil et al., 2021). All images use ConTeXt camera data.…”