Geological mapping of North-West Mount Sharp region (Gale crater, Mars) and connections with data from Curiosity rover

The exploration of Gale Crater on Mars has returned a great amount of data, offering insights into the planet's geological history. However, to fully understand its evolution, comprehensive analysis at various scales is essential. This study focuses on geological mapping, stratigraphy and structural analysis transitioning from a regional scale to a local scale to establish the evolution of Gale Crater. The primary goal of this research is to clarify the structural and stratigraphic relationships among the sedimentary layers within the North-West part of Gale Crater, providing insights into the sedimentary environment at the moment of their deposition as well as the deformational history while the sequence of Mount Sharp was built up and shaped. The dataset used for this study was acquired both by orbital [1] and rover missions [2]. Merged DEM and Orthophoto were made by MSL team from HiRISE stereopairs for the needs of the Curiosity mission with resolution 1 and 0.25 (m/pixel) respectively [2]. For obtaining colored information we used the CASSIS image. The alignment and pansharpening process was conducted using the open-source PANCO suite, which automates co-registration of CaSSIS multispectral data with reference panchromatic images through computer vision algorithms, refines results manually, and employs an adapted Gram-Schmidt Adaptive method [4]. This process improves the color image resolution up to 18 times using a panchromatic image mosaic orthophoto as the base. As the result of mapping, we updated the stratigraphic column with unit’s description combined with observation from ground data and the previous literature and research. The novelty of the stratigraphic column lies in its organization based not on the rover’s traverse sequence but on a rigorous stratigraphic order which allowed us to infer the sequence of geological events in the region. As already highlighted by previous authors [5] the area exhibits a transition from a lacustrine environment to an aeolian one. We propose three new members on the upper part of the Mirador formation. Additionally in the middle of Mirador formation we have recognized two erosional events preceding a significant climatic shift which led to the final part of the studied series made up of a sulphate rich sedimentary sequence interpreted as aeolian facies with local broad cross stratification. Structurally, the region shows a low average dip of approximately 5 degrees towards the NW, with local variations possibly caused by gentle folding both before and after the detected unconformities.

Acknowledgements: This study was carried out within the Space It Up project funded by the Italian Space Agency, ASI, and the Ministry of University and Research, MUR, under contract n. 2024-5-E.0 - CUP n. I53D24000060005

[1] University of Bern (2024) MY36_018708_356_0 https://observations.cassis.unibe.ch/. [2] MSL, NASA (2011). Curiosity Analyst’s Notebook https://an.rsl.wustl.edu/msl/AN/an3.aspx. [3] Calef III F. J. and P. T. (2016) PDS Annex, U.S.G.S. [4] Tullo A. (2024) PSS 105997. [5] Meyer, M. J. (2024). GSA b37355.1