A downscaling approach for geological characterization of the Raditladi basin of Mercury

In this work, we combined multi-scale geological maps of Mercury to produce a new global map where geological units are classified based on albedo, crater density and morphological relationships with other units. To create this map, we used the 250 m/pixel mosaic of images acquired by the narrow- and wide-angle cameras onboard the MErcury Surface, Space ENviron- ment, GEochemistry, and Ranging (MESSENGER) spacecraft during its orbital phase. The geo- logical mapping is supported by digital terrain model data and surface mineralogical variation from the global mosaic of MESSENGER Mercury Atmospheric and Surface Composition Spec- trometer observations. This map comprises the global-scale intercrater plains, smooth plains and Odin-type units as reported in previous studies, as well as units we term bright intercrater plains, Caloris rough ejecta and dark material deposits. We mapped a portion of the Raditladi quadrangle (19-358N, 106-1338E) at a regional scale at a resolution of 166 m/pixel. We characterized the geological context of the area and evaluated the stratigraphic relationships between the units. To obtain a representative geological section, we analysed and corrected available topographical data. The geological cross-section derived from our regional mapping suggests that volcanic emplacement of Raditladi's inner plains followed the topography of the basin after the deposition of impact-related units (i.e. melts, breccias and rim collapse) and was driven by low-viscosity flows. Hollows that appear on Raditladi's peak ring were possibly formed from low-reflectance intercrater plains materials exposed through the peak ring unit.