Geological mapping of Kuiper Crater: a break within Mercury crust

The results from planetary investigation in the last years strongly point out that the integration of compositional information with the morphology, stratigraphy and tectonics permits to produce a more comprehensive geological approach, obtaining geological maps instead of purely morpho-stratigraphic maps. In this view, firstly PLANMAP project, and then GMAP (within EUROPLANET-RI 20-24), have given indications on different approaches to follow for such integration.Investigating the surface of Mercury is an important task of the Bepicolombo mission. To be prepared for this task we are investigating the data obtained by past MESSENGER mission in order to understand which geological features and/or region of Mercury should hide key information.In this work we investigate the Kuiper crater (62 kilometer in diameter) which overlies the northern rim of the larger crater Murasaki. The Kuiper crater is one of the highest albedo features on the surface of Mercury with an important ray system, indicative of its young age. From this point of view Kuiper can be considered an important feature on hermean surface history, such as to give the name at the last period of Mercury timeline (the Kuiperian age). However, on the other side,its relatively young age does not permit it to investigate the local geology by using the global basemaps, since the albedo is saturating within the crater, making difficult to understand the variegation on it and on the proximal and distal ejecta. Whereas considering the color variegation from the different filters of the WAC camera onboard MESSENGER, at relatively high spatial resolution (385 m/px), we clearly highlighted how several peculiar geological features arise. These regions have been later investigated by ad-hoc mosaics considering the highest resolution images available (~ 120 m/pixel) from the NAC camera onboard MESSENGER.The extension of the ejecta could be improved and differentiated from reflectance properties of the crater floor, showing an asymmetry towards S-SE. Moreover, the crater wall seems to reveal the possible impact direction. Evidence of pyroclastic-like material, from spectral reflectance properties, are present on the N-E wall, whereas from north to west the terraced wall seems to show the presence of re-melted material. Interestingly, two different hollows-like terrain are present on both the inner peaks and on the southern wall, indicating that hollows could be emplaced on different bedrock terrains. In addition, the spectral indication shows a clear distinction from Kuiper material with respect to the Murasaki terrains.We want to acknowledge the GMAP, Europlanet RI 20-24 grant n.: 871149-GMAP and the Bepicolombo (SIMBIO-SYS) project, ASI-INAF agreement n.: 2017-47-H.