Abstract Jezero crater is located in Mars’ largest olivine-rich region, which is variously interpreted as lava flows, intrusive plutons, clastic sediments, or pyroclastics. In Jezero crater, several olivine-rich units have been investigated by the Perseverance rover, including an olivine cumulate in the crater floor (Séítah formation) and the enigmatic “Margin Unit”; an olivine- and carbonate-rich unit commonly interpreted as either a lake shore deposit or a local expression of the regional olivine-carbonate unit. We developed a method incorporating X-ray diffraction energy and spatial information to accurately determine the forsterite content (molar percentage of MgO/(MgO+FeOT)) of monocrystalline olivine encountered by Perseverance . Forsterite content in clastic sediments of the western Jezero fan indicate multiple olivine sources. In contrast, forsterite content analysed in the Margin Unit is similar to the Séítah formation, suggesting that at least some of the Margin Unit may represent an altered igneous cumulate with similar origins to the Séítah formation.
Orenstein et al. (Wed,) studied this question.