A fragile record of fleeting water on Mars

Abstract The light-toned sedimentary layers that outcrop widely throughout Mars’ Southern Highlands have long been an enigma in uncovering the climatic history of Mars. Although these units seem to contain unique records fluctuating surface conditions, role water their formation is debated. A distinctive property many such deposits elevated thermal inertia relative surrounding materials. This temperature-controlling trait often interpreted indicate induration resulting from aqueous processes. However, prevalent erosional landforms suggest host much weaker materials than neighboring units. We address this apparent contradiction by disentangling relationships between inertia, mineralogy, and erosion susceptibility quantifying cohesion layered Arabia Terra region. demonstrate variations dust cover associated with erodibility eolian abrasion can be inconspicuous controls on inertia. ultimately find are not as cohesive would expected a high water-to-rock ratio setting either during or after deposition. If water-rich conditions existed region Noachian, they may only intermittent fleeting.