Samples collected at the Jezero Crater Floor
The samples collected from the Crater Floor represent a suite of likely petrogenetically related igneous rocks emplaced as lava flows and intrusions mostly postdating the delta and displaying variable degrees of aqueous alteration (e.g., Udry et al., 2022; Simon et al., 2023).
The intrusive samples link to Séítah formation, likely the oldest of the crater floor, and were sampled at the localities Brac and Issole. Based on texture and mineralogy, they represent olivine cumulate with poikilitic textures (Liu et al., 2022), with accessory augite and plagioclase. This formation also records carbonates and phyllosilicates, implying carbonation and salt precipitation during its history.
The samples recovered at Brac are named Salette and Coulettes. The samples recovered at Issole are named Robine and Malay. The samples from Issole show less signs of alteration, but carbonates and hydrated sulfates are also present.
The second observed formation is Máaz, composed of lava flows and sampled at Rochette (Lower Máaz) and Sid (Upper Máaz). Cached rocks represent holocrystalline augite basalt (Farley et al., 2022), although the Lower and Upper Máaz differ in textures and in plagioclase crystal sizes. The first samples, recovered at Rochette are called Montdenier and Montagnac and are finer textured. The second set of samples, collected at the Sid locality, are called Atsah and Ha`ahoni and present larger scale crystals of plagioclase. Samples from Máaz additionally record aqueous activity: sulfates, perchlorates, silicates, carbonates and phosphates fill the voids in the Máaz formation rocks, although set of samples from Sid show less alteration.
Samples collected from the Delta Front
Delta Front samples represent fluvial to deltaic sediments formed by the transport and deposition of materials from the Jezero watershed. The samples include fine-grained, sulfate- and carbonate-bearing mudstones (Benison et al., 2024; Stack et al., 2024) sampled at Amalik, Skinner Ridge and Wildcat Ridge.
The samples Mageik and Shuyak, recovered at the Amalik site, appear to be mudstones with olivine framework. They contain salts such as sulfates and dolomite in cement, as well as silica. They are likely to derive from rocks compositionally similar to Seitah formation, but having undergone subaqueous alteration. The samples from the Amalik outcrop appear less oxidized than the rest of the Delta, richer in olivine and poorer in sulfates.
The samples from Skinner Ridge are Swift Run and Skyland. Those are sandstones which contain larger clasts (up to 2 mm in diameter) compared to mudstones from Amalik. Grain framework of rocks from sinner Ridge is dominated by detrital fragments. The fragments vary in composition, from mafic minerals to alteration products such as phyllosilicates. The matrix cementing those rocks is interpreted to be Fe,Mg-rich carbonate. These samples present evidence of alteration and oxidation.
Finally, the samples from Wildcat Ridge, Bearwallow and Hazeltop, are well sorted, layered and fine grained mudstones with weakly hydrated sulfate inclusions. They also contain small amounts of clay, hydrated silica, and possibly carbonates. These two samples tend to contain less inclusions than the other delta sediments.
Additionally, one sample of loose regolith was cached at Hidden Harbor. The sample and its backup are named Atmo Mountain and Crosswind Lake. It appears as this regolith is a mix of sedimentary and igneous dust collected from an inactive mega ripple. In texture, it is a mix of coarse grains (<5 mm) and finer sand (~150 μm). The alteration of the different phases appears to be heterogeneous.
