The evolution of lacustrine environments on Mars: Is Mars only hydrologically dormant?

This study surveys the evolution of martian impact crater paleolakes through time by establishing their age, comparing their locations, and describing the formation of lacustrine sedimentary structures and features over time. We explore their meaning in terms of global climate changes, but also on local and regional scales. We observe a co-location between recent impact crater paleolakes and regions where GCM modeling shows that Mars is currently experiencing days above triple point and below boiling point of water. Some source areas show morphologies that could be consistent with ancient glacier features in the Argyre Basin/Darwin Crater region, in locations that are also consistent with GCM models of past snow precipitation on Mars. We propose that, at least for some paleolakes, our results are best explained by recent, and abundant, aqueous activity on Mars, with some meteorological contribution. These results are supported by other recent findings on martian meteorite ages, by the analysis of new MGS data showing recent volcanic and fluvial activity, and by climate modeling. They point toward the possibility that Mars currently is only hydrologically dormant and that there is a potential for hydrological activity to be generated again in the future following changes in the planet's orbital parameters. (C) 2001 Academic Press.