An olivine cumulate outcrop on the floor of Jezero crater, Mars

Liu, Y.; Tice, M. M.; Schmidt, M. E.; Treiman, A. H.; Kizovski, T. V.; Hurowitz, J. A.; Allwood, A. C.; Henneke, J.; Pedersen, D. A. K.; VanBommel, S. J.; Jones, M. W. M.; Knight, A. L.; Orenstein, B. J.; Clark, B. C.; Elam, W. T.; Heirwegh, C. M.; Barber, T.; Beegle, L. W.; Benzerara, K.; Bernard, S.; Beyssac, O.; Bosak, T.; Brown, A. J.; Cardarelli, E. L.; Catling, D. C.; Christian, J. R.; Cloutis, E. A.; Cohen, B. A.; Davidoff, S.; Fairen, A. G.; Farley, K. A.; Flannery, D. T.; Galvin, A.; Grotzinger, J. P.; Gupta, S.; Hall, J.; Herd, C. D. K.; Hickman-Lewis, K.; Hodyss, R. P.; Horgan, B. H. N.; Johnson, J. R.; Jorgensen, J. L.; Kah, L. C.; Maki, J. N.; Mandon, L.; Mangold, N.; McCubbin, F. M.; McLennan, S. M.; Moore, K.; Nachon, M.; Nemere, P.; Nothdurft, L. D.; Nunez, J. I.; O'Neil, L.; Quantin-Nataf, C. M.; Sautter, V.; Shuster, D. L.; Siebach, K. L.; Simon, J. I.; Sinclair, K. P.; Stack, K. M.; Steele, A.; Tarnas, J. D.; Tosca, N. J.; Uckert, K.; Udry, A.; Wade, L. A.; Weiss, B. P.; Wiens, R. C.; Williford, K. H.; Zorzano, M-P.
2022
SCIENCE
DOI
10.1126/science.abo2756
The geological units on the floor of Jezero crater, Mars, are part of a wider regional stratigraphy of olivine-rich rocks, which extends well beyond the crater. We investigated the petrology of olivine and carbonate-bearing rocks of the Seitah formation in the floor of Jezero. Using multispectral images and x-ray fluorescence data, acquired by the Perseverance rover, we performed a petrographic analysis of the Bastide and Brac outcrops within this unit. We found that these outcrops are composed of igneous rock, moderately altered by aqueous fluid. The igneous rocks are mainly made of coarsegrained olivine, similar to some martian meteorites. We interpret them as an olivine cumulate, formed by settling and enrichment of olivine through multistage cooling of a thick magma body.