Aeolian Sediment Lithification From Late-Stage Aqueous Activity in the Gale Crater: Implications for Habitability on Mars

Abstract

The presence of lithified aeolian deposits on the Martian surface indicates the existence of wet environments during the later stages of the planet's geological history. NASA's Curiosity rover observed lithified forms of aeolian sediments stratified as Stimson formation (SF) on several occasions in the Gale crater, including Greenheugh pediment (GP). The lithification process leading to well-preserved aeolian sediments remains uncertain during the dry period. Our prime focus is on the youngest water flow and cementation of SF at northern and eastern GP sites. Earlier studies of the lower GP site pointed out concretion-enriched unconformity, suggesting surface runoff. We have investigated the regional variation of eastern and northern GP sites and local variation in lower and upper SF strata. To understand the SF lithification process on the Gale crater, we utilized lithified aeolian deposits in analogue sites in the UAE. This research encompasses several key aspects: (a) reconstructing regional and local water flow dynamics in dunes, based on comparison with rover images and terrestrial analogue studies, (b) investigating the SF dunes aquifer system, (c) exploring the calcium sulfate cementation, concretions formation, and organic preservation in SF from analogue studies, and (d) investigating the habitability of water-saturated zones in dune analogues. The water flow along the unconformity and saturation within the dunes suggest that the unconformity could be a potential habitable zone on Mars. This study highlights the significance of lithified dunes as prime targets for the search for life on Mars.