Elemental Geochemistry of Sedimentary Rocks at Yellowknife Bay, Gale Crater, Mars

• Published in: Science
• Main Authors: Mclennan, S. M., Anderson, R. B., Bell, J. F., Bridges, J. C., Calef, F., Campbell, J. L., Clark, B. C., Clegg, S., Conrad, P., Cousin, A., Des Marais, D. J., Dromart, Gilles, Dyar, M. D., Edgar, L. A., Ehlmann, B. L., Fabre, C., Forni, O., Gasnault, O., Gellert, R., Gordon, S., Grant, J. A., Grotzinger, J. P., Gupta, S., Herkenhoff, K. E., Hurowitz, J. A., King, P. L., Le Mouelic, S., Leshin, L. A., Leveille, R., Lewis, K. W., Mangold, N., Maurice, S., Ming, D. W., Morris, R. V., Nachon, M., Newsom, H. E., Ollila, A. M., Perrett, G. M., Rice, M. S., Schmidt, M. E., Schwenzer, S. P., Stack, K., Stolper, E. M., Sumner, D. Y., Treiman, A. H., Vanbommel, S., Vaniman, D. T., Vasavada, A., Wiens, R. C., Yingst, R. A., Team, M. S. L. Sci
• Other Authors: Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), GeoRessources, Institut national des sciences de l'Univers (INSU - CNRS)-Centre de recherches sur la géologie des matières premières minérales et énergétiques (CREGU)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), MSL Science Team, Laboratoire de Planétologie et Géodynamique UMR 6112 (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2014
• Subjects: [SDU.STU]Sciences of the Universe [physics]/Earth Sciences; Yellowknife; Yellowknife Bay
• Online Access: https://hal.science/hal-01303021; https://doi.org/10.1126/science.1244734

International audience Sedimentary rocks examined by the Curiosity rover at Yellowknife Bay, Mars, were derived from sources that evolved from an approximately average martian crustal composition to one influenced by alkaline basalts. No evidence of chemical weathering is preserved, indicating arid, possibly cold, paleoclimates and rapid erosion and deposition. The absence of predicted geochemical variations indicates that magnetite and phyllosilicates formed by diagenesis under low-temperature, circumneutral pH, rock-dominated aqueous conditions. Analyses of diagenetic features (including concretions, raised ridges, and fractures) at high spatial resolution indicate that they are composed of iron-and halogen-rich components, magnesium-iron-chlorine-rich components, and hydrated calcium sulfates, respectively. Composition of a cross-cutting dike-like feature is consistent with sedimentary intrusion. The geochemistry of these sedimentary rocks provides further evidence for diverse depositional and diagenetic sedimentary environments during the early history of Mars.