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 Fe^(2+) 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. Fe^(2+)-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.
Additional Information
© 2008 American Association for the Advancement of Science. Received for publication 28 April 2008; accepted for publication 17 June 2008. The authors thank E. Cloutis and an anonymous reviewer for helpful editorial comments and the CRISM Science Team for acquisition of the images. Supported by NASA's Mars Reconnaissance Orbiter project, Mars Data Analysis program, Mars Fundamental Research program, and the NASA Astrobiology Institute.Attached Files
Accepted Version - nihms-1048613.pdf
Supplemental Material - 1159699s1.mpeg
Supplemental Material - Bishop.SOM.pdf
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Additional details
- PMCID
- PMC7007808
- Eprint ID
- 34903
- DOI
- 10.1126/science.1159699
- Resolver ID
- CaltechAUTHORS:20121015-131020298
- NASA Mars Reconnaissance Orbiter project
- NASA Astrobiology Institute
- Created
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2012-10-15Created from EPrint's datestamp field
- Updated
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2021-11-09Created from EPrint's last_modified field
- Caltech groups
- Division of Geological and Planetary Sciences