Constraints on the history of open-basin lakes on Mars from the composition and timing of volcanic resurfacing

[1] Abundant evidence exists for valley network-related fluvial activity near the Noachian-Hesperian transition on Mars, and areally significant quantities of volcanic ridged plains were emplaced during this period as well. Thus, it is worthwhile to explore the hypothesis that lava-water interaction occurred on the surface of Mars at this time. We analyzed the morphology, physical properties, composition, and surface ages of thirty open-basin lakes (topographic lows with both an inlet valley and an outlet valley) that were also resurfaced by volcanic flows. Hyperspectral imaging data from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) and Observatoire pour la Minéralogie, l’Eau, les Glaces et l’Activité (OMEGA) instruments indicate that of the 30 basins, 12 exhibit the spectral properties of basaltic lithologies with diagnostic absorptions of olivine, high-calcium pyroxene and low-calcium pyroxene. An olivine/high-calcium pyroxene mixture is the most commonly identified mineral assemblage, consistent with other Hesperian-aged volcanic units. Therefore, our mineralogical results for over a third of the open-basin lake floors analyzed support prior interpretations that the basins were resurfaced by volcanic flows. Supporting evidence fo