A hybrid geological map of Sibelius crater on Mercury, and its associated ejecta and impact melt deposits

Canale, Marc; Wright, Jack and Rothery, David A. (2024). A hybrid geological map of Sibelius crater on Mercury, and its associated ejecta and impact melt deposits. Geological Society, London, Special Publications, 541(1)

DOI: https://doi.org/10.1144/SP541-2022-296

Abstract

Using MESSENGER Mercury Dual Imaging System data, we produced 3 new maps of Sibelius Crater, Mercury. Geomorphological and spectral maps were combined into a single hybrid map containing units associated with ejecta deposits, crater floor landforms and impact melt ponding. Spatial measurement of these units show that ~50% of the mapped melt pond area lies within a large, degraded impact crater (crater B), beyond the significantly lower northern Sibelius rim, with a potential melt flow to a smaller, degraded impact structure further north (crater C). Freshly processed spectral data from the 8-color Map Projected Multispectral Reduced Data Record (MDR) data highlight the emplacement of multiple uplifted ejecta units with distinct spectral properties. A new, high resolution digital elevation model was created to help define and analyse crater floor uplift features, disrupted crater rims and to create detailed cross sections. These illustrate a proposed location of B’s central uplift structure exposed in the northern wall slopes of Sibelius. Small features at the limit of visibility, such as a groove possibly associated with a rolling or sliding mega-boulder, and lobate melt flow on the crater floor with accompanying channel opening, are highlighted for future investigations by BepiColombo’s instruments once it reaches orbit.