Publication Date:
2014-01-25
Description:
Opportunity has investigated in detail rocks on the rim of the Noachian age Endeavour crater, where orbital spectral reflectance signatures indicate the presence of Fe(+3)-rich smectites. The signatures are associated with fine-grained, layered rocks containing spherules of diagenetic or impact origin. The layered rocks are overlain by breccias, and both units are cut by calcium sulfate veins precipitated from fluids that circulated after the Endeavour impact. Compositional data for fractures in the layered rocks suggest formation of Al-rich smectites by aqueous leaching. Evidence is thus preserved for water-rock interactions before and after the impact, with aqueous environments of slightly acidic to circum-neutral pH that would have been more favorable for prebiotic chemistry and microorganisms than those recorded by younger sulfate-rich rocks at Meridiani Planum.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Arvidson, R E -- Squyres, S W -- Bell, J F 3rd -- Catalano, J G -- Clark, B C -- Crumpler, L S -- de Souza, P A Jr -- Fairen, A G -- Farrand, W H -- Fox, V K -- Gellert, R -- Ghosh, A -- Golombek, M P -- Grotzinger, J P -- Guinness, E A -- Herkenhoff, K E -- Jolliff, B L -- Knoll, A H -- Li, R -- McLennan, S M -- Ming, D W -- Mittlefehldt, D W -- Moore, J M -- Morris, R V -- Murchie, S L -- Parker, T J -- Paulsen, G -- Rice, J W -- Ruff, S W -- Smith, M D -- Wolff, M J -- New York, N.Y. -- Science. 2014 Jan 24;343(6169):1248097. doi: 10.1126/science.1248097.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Earth and Planetary Sciences, Washington University in Saint Louis, St. Louis, MO 63130, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/24458648" target="_blank"〉PubMed〈/a〉
Keywords:
Bacteria
;
*Exobiology
;
Extraterrestrial Environment/*chemistry
;
Geologic Sediments
;
Hydrogen-Ion Concentration
;
*Mars
;
Silicates/analysis/chemistry
;
Spacecraft
;
Sulfates/chemistry
;
*Water
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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