Mars, Always Cold, Sometimes Wet: New Constraints on Mars Denudation Rates and Climate Evolution from Analog Studies at Haughton Crater, Devon Island, High Arctic

Analysis of crater modification on Mars and at Haughton Crater, Devon Island, High Arctic, which was recently shown to be significantly older than previously believed (Eocene age instead of Miocene) [1], suggest that Mars may have never been climatically wet and warm for geological lengths of time during and since the Late Noachian. Impact structures offer particularly valuable records of the evolution of a planet s climate and landscape through time. The state of exposure and preservation of impact structures and their intracrater fill provide clues to the nature, timing, and intensity of the processes that have modified the craters since their formation. Modifying processes include weathering, erosion, mantling, and infilling. In this study, we compare the modification of Haughton through time with that of impact craters in the same size class on Mars. We derive upper limits for time-integrated denudation rates on Mars during and since the Late Noachian. These rates are significantly lower than previously published and provide important constraints for Mars climate evolution.