Combined remote sensing analyses and landform evolution modeling reveal the terrestrial Bosumtwi impact structure as a Mars-like rampart crater

Abstract We combine remote sensing and geomorphological analyses with landform evolution modeling to investigate whether or not terrestrial impact crater morphologies are comparable with martian impact craters formed in volatile-rich environments. We conduct a detailed remote sensing analysis of the terrestrial Bosumtwi crater in Ghana (10.5 km, 1.07 Ma) investigating its geology and geomorphology. This includes a morphometric analysis of the drainage pattern from digital elevation models and the interpretation of multi-spectral image data. The results are compared with a fresh martian impact crater of similar size for which a hypothetical drainage network and catchment areas are derived. We investigate whether the current morphology of Bosumtwi crater results from erosion of a typical martian-type or lunar-type impact crater morphology using landform evolution modeling. Our results reveal that the morphology of Bosumtwi crater cannot be explained by erosion of a lunar-like impact crater. In contrast, the morphological and spectral characteristics of Bosumtwi crater exhibit striking similarities to those of martian rampart craters, especially double-layered ejecta craters. We therefore suggest that Bosumtwi crater was originally built as a Mars-like rampart crater, and that the current morphology is the result of weakly eroded ejecta ramparts.