Paleoshorelines and the Evolution of the Lithosphere of Mars

Abstract

The existence of features indicative of shorelines of ancient oceans on Mars has been proposed for several authors. In this chapter we revise the topography of possible Martian paleoshorelines, and their consequences for the amount of water infilling ocean basins when water load is considered. We show that a re-evaluation of paleoshorelines is need. For example, the putative Meridiani shoreline could be the same feature as some portions of the Arabia shoreline. Indeed, elevations in the Meridiani shoreline are roughly similar to that of the Arabia shoreline in northeast Arabia, Utopia (not taken into account the Isidis basin), Elysium, and Amazonis regions. This is still far of an equipotential surface, but a paleoshoreline through these regions and the Meridiani horeline would be better candidate to represent a paleoequipotential surface than the Arabia shoreline sensu strito. Moreover, the elevation of the Arabia shoreline in northern Arabia Terra after is intriguingly close to the mean elevation of the Deuteronilus shoreline, and it cannot be discarded a “mixed” Arabia/Deuteronilus shoreline, which would include the Arabia shoreline in northern Arabia Terra, and the Deuteronilus shoreline elsewhere.