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Clay mineral diversity and abundance in sedimentary rocks of Gale crater, Mars

Clay minerals provide indicators of the evolution of aqueous conditions and possible habitats for life on ancient Mars. Analyses by the Mars Science Laboratory rover Curiosity show that ~3.5–billion year (Ga) fluvio-lacustrine mudstones in Gale crater contain up to ~28 weight % (wt %) clay minerals....

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Detalles Bibliográficos
Autores principales: Bristow, Thomas F., Rampe, Elizabeth B., Achilles, Cherie N., Blake, David F., Chipera, Steve J., Craig, Patricia, Crisp, Joy A., Des Marais, David J., Downs, Robert T., Gellert, Ralf, Grotzinger, John P., Gupta, Sanjeev, Hazen, Robert M., Horgan, Briony, Hogancamp, Joanna V., Mangold, Nicolas, Mahaffy, Paul R., McAdam, Amy C., Ming, Doug W., Morookian, John Michael, Morris, Richard V., Morrison, Shaunna M., Treiman, Allan H., Vaniman, David T., Vasavada, Ashwin R., Yen, Albert S.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Association for the Advancement of Science 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5990309/
https://www.ncbi.nlm.nih.gov/pubmed/29881776
http://dx.doi.org/10.1126/sciadv.aar3330
Descripción
Sumario:Clay minerals provide indicators of the evolution of aqueous conditions and possible habitats for life on ancient Mars. Analyses by the Mars Science Laboratory rover Curiosity show that ~3.5–billion year (Ga) fluvio-lacustrine mudstones in Gale crater contain up to ~28 weight % (wt %) clay minerals. We demonstrate that the species of clay minerals deduced from x-ray diffraction and evolved gas analysis show a strong paleoenvironmental dependency. While perennial lake mudstones are characterized by Fe-saponite, we find that stratigraphic intervals associated with episodic lake drying contain Al-rich, Fe(3+)-bearing dioctahedral smectite, with minor (3 wt %) quantities of ferripyrophyllite, interpreted as wind-blown detritus, found in candidate aeolian deposits. Our results suggest that dioctahedral smectite formed via near-surface chemical weathering driven by fluctuations in lake level and atmospheric infiltration, a process leading to the redistribution of nutrients and potentially influencing the cycling of gases that help regulate climate.