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Phyllosilicate diversity and past aqueous activity revealed at Mawrth Vallis, Mars.

ABSTRACT: Observations by the Mars Reconnaissance Orbiter/Compact Reconnaissance Imaging Spectrometer for Mars in the Mawrth Vallis region show several phyllosilicate species, indicating a wide range of past aqueous activity. Iron/magnesium (Fe/Mg)-smectite is observed in light-toned outcrops that probably formed via aqueous alteration of basalt of the ancient cratered terrain. This unit is overlain by rocks rich in hydrated silica, montmorillonite, and kaolinite that may have formed via subsequent leaching of Fe and Mg through extended aqueous events or a change in aqueous chemistry. A spectral feature attributed to an Fe2+ phase is present in many locations in the Mawrth Vallis region at the transition from Fe/Mg-smectite to aluminum/silicon (Al/Si)-rich units. Fe2+-bearing materials in terrestrial sediments are typically associated with microorganisms or changes in pH or cations and could be explained here by hydrothermal activity. The stratigraphy of Fe/Mg-smectite overlain by a ferrous phase, hydrated silica, and then Al-phyllosilicates implies a complex aqueous history.

SUBMITTER: Bishop JL

PROVIDER: S-EPMC7007808 | biostudies-literature | 2008 Aug

REPOSITORIES: biostudies-literature

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Phyllosilicate diversity and past aqueous activity revealed at Mawrth Vallis, Mars.

Bishop Janice L JL Dobrea Eldar Z Noe EZ McKeown Nancy K NK Parente Mario M Ehlmann Bethany L BL Michalski Joseph R JR Milliken Ralph E RE Poulet Francois F Swayze Gregg A GA Mustard John F JF Murchie Scott L SL Bibring Jean-Pierre JP

Science (New York, N.Y.) 20080801 5890

Observations by the Mars Reconnaissance Orbiter/Compact Reconnaissance Imaging Spectrometer for Mars in the Mawrth Vallis region show several phyllosilicate species, indicating a wide range of past aqueous activity. Iron/magnesium (Fe/Mg)-smectite is observed in light-toned outcrops that probably formed via aqueous alteration of basalt of the ancient cratered terrain. This unit is overlain by rocks rich in hydrated silica, montmorillonite, and kaolinite that may have formed via subsequent leachi ...[more]

PMID: 18687963

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Phyllosilicate diversity and past aqueous activity revealed at Mawrth Vallis, Mars.

Publications

Phyllosilicate diversity and past aqueous activity revealed at Mawrth Vallis, Mars.

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