Mineralogical Diversity in the Upper Fan Campaign at Jezero Crater, Mars

Abstract Noachian‐aged Jezero crater, the landing site of the Perseverance rover, recorded a fan‐delta system associated with fluvial‐lacustrine features, indicating the past presence of a paleolake. However, the collected targets at the Jezero crater floor indicate that igneous units exhibit distinctive mineralogical features, including the co‐occurrence of different hydrated salts as evidence of later alteration by fluids. In this work, we analyzed the SHERLOC Raman spectra and micro‐images of seven targets in the upper fan unit at Jezero crater during the third science campaign. Mineral detection in these abraded patches consists of carbonate, sulfate, perchlorate or phosphate, and silicate phases (including olivine and pyroxene). The widespread distribution of carbonate minerals in this region indicates a prominent sedimentary deposit potentially related to the Martian paleolakes or transport and deposit processes of rivers or water flows. In four targets, sulfate phases containing anhydrite and hydrous Ca‐sulfate were also identified. These phases were possibly formed from sulfate‐rich low‐temperature fluids. An alternative mechanism for sulfate formation involves the interaction between sedimentary rocks and fluids in either dilute brines under high‐temperature conditions or concentrated brines in low‐temperature environments. The prolonged processes of fluvial, flooding, and eolian sedimentation have significantly reshaped the lithified sediments of Jezero crater, contributing to mineralogical diversity between the crater floor and delta.