A Mars 2020 Perseverance SuperCam Perspective on the Igneous Nature of the Máaz Formation at Jezero Crater and Link With Séítah, Mars

The Máaz formation consists of the first lithologies in Jezero crater analyzed by the Mars 2020Perseverance rover. This formation, investigated from Sols (Martian days) 1 to 201 and from Sols 343 to 382,overlies the Séítah formation (previously described as an olivine-rich cumulate) and was initially suggested torepresent an igneous crater floor unit based on orbital analyses. Using SuperCam data, we conducted a detailedtextural, chemical, and mineralogical analyses of the Máaz formation and the Content member of the Séítahformation. We conclude that the Máaz formation and the Content member are igneous and consist of differentlava flows and/or possibly pyroclastic flows with complex textures, including vesicular and non-vesicular rockswith different grain sizes. The Máaz formation rocks exhibit some of the lowest Mg# (=molar 100 × MgO/MgO + FeO) of all Martian igneous rocks analyzed so far (including meteorites and surface rocks) and showsimilar basaltic to basaltic-andesitic compositions. Their mineralogy is dominated by Fe-rich augite to possiblyferrosilite and plagioclase, and minor phases such as Fe-Ti oxides and Si-rich phases. They show a broaddiversity of both compositions and textures when compared to Martian meteorites and other surface rocks. Thedifferent Máaz and Content lava or pyroclastic flows all originate from the same parental magma and/or thesame magmatic system, but are not petrogenetically linked to the Séítah formation.