Publication Date:
2013-12-11
Description:
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.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉McLennan, S M -- Anderson, R B -- Bell, J F 3rd -- Bridges, J C -- Calef, F 3rd -- Campbell, J L -- Clark, B C -- Clegg, S -- Conrad, P -- Cousin, A -- Des Marais, D J -- Dromart, G -- 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 -- MSL Science Team -- New York, N.Y. -- Science. 2014 Jan 24;343(6169):1244734. doi: 10.1126/science.1244734. Epub 2013 Dec 9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Geosciences, State University of New York, Stony Brook, NY 11794, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/24324274" target="_blank"〉PubMed〈/a〉
Keywords:
Bays
;
Calcium Sulfate/analysis/chemistry
;
Chlorine/analysis/chemistry
;
*Exobiology
;
Extraterrestrial Environment/*chemistry
;
Ferrosoferric Oxide/analysis/chemistry
;
Geologic Sediments/*chemistry
;
Halogens/analysis/chemistry
;
Hydrogen-Ion Concentration
;
Iron/analysis/chemistry
;
Magnesium/analysis/chemistry
;
*Mars
;
Silicates/analysis/chemistry
;
Water/chemistry
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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