Linked Life Data

11539475

Source:http://linkedlifedata.com/resource/pubmed/id/11539475

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
1997-8-2
pubmed:abstractText
Considerable evidence points to a martian origin of the SNC meteorites. Noble gas isotopic compositions have been measured in most SNC meteorites. The 129Xe/132Xe vs, 84Kr/132Xe ratios in Chassigny, most shergottites, and lithology C of EETA 79001 define a linear array. This array is thought to be a mixing line between martian mantle and martian atmosphere. One of the SNC meteorites, Nakhla, contains a leachable component that has an elevated 129Xe/132Xe ratio relative to its 84Kr/132Xe ratio when compared to this approximately linear array. The leachable component probably consists in part of iddingsite, an alteration product produced by interaction of olivine with aqueous fluid at temperatures lower than 150 degrees C. The elevated Xe isotopic ratio may represent a distinct reservoir in the martian crust or mantle. More plausibly, it is elementally fractionated martian atmosphere. Formation of sediments fractionates the noble gases in the correct direction. The range of sediment/atmosphere fractionation factors is consistent with the elevated 129Xe/132Xe component in Nakhla being contained in iddingsite, a low temperature weathering product. The crystallization age of Nakhla is 1.3 Ga. Its low-shock state suggests that it was ejected from near the surface of Mars. As liquid water is required for the formation of iddingsite, these observations provide further evidence for the near surface existence of aqueous fluids on Mars more recently than 1.3 Ga.
pubmed:keyword
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
S
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0026-1114
pubmed:author
pubmed:issnType
Print
pubmed:volume
29
pubmed:owner
NASA
pubmed:authorsComplete
Y
pubmed:pagination
854-9
pubmed:dateRevised
2007-7-17
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Fractionated martian atmosphere in the nakhlites?
pubmed:affiliation
Lunar and Planetary Laboratory, University of Arizona, Tucson 85721, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S.