Publication Date:
2011-11-05
Description:
Clay minerals, recently discovered to be widespread in Mars's Noachian terrains, indicate long-duration interaction between water and rock over 3.7 billion years ago. Analysis of how they formed should indicate what environmental conditions prevailed on early Mars. If clays formed near the surface by weathering, as is common on Earth, their presence would indicate past surface conditions warmer and wetter than at present. However, available data instead indicate substantial Martian clay formation by hydrothermal groundwater circulation and a Noachian rock record dominated by evidence of subsurface waters. Cold, arid conditions with only transient surface water may have characterized Mars's surface for over 4 billion years, since the early-Noachian period, and the longest-duration aqueous, potentially habitable environments may have been in the subsurface.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Ehlmann, Bethany L -- Mustard, John F -- Murchie, Scott L -- Bibring, Jean-Pierre -- Meunier, Alain -- Fraeman, Abigail A -- Langevin, Yves -- England -- Nature. 2011 Nov 2;479(7371):53-60. doi: 10.1038/nature10582.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Institut d'Astrophysique Spatiale, Universite de Paris-Sud XI, 91405 Orsay Cedex, France. ehlmann@caltech.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/22051674" target="_blank"〉PubMed〈/a〉
Keywords:
Aluminum Silicates/*analysis/*chemistry/classification
;
Exobiology
;
Extraterrestrial Environment/*chemistry
;
Groundwater/*analysis
;
Ice/analysis
;
*Mars
;
Silicates/chemistry
Print ISSN:
0028-0836
Electronic ISSN:
1476-4687
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
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