Noble gas evidence of an aqueous reservoir near the surface of Mars more recently than 1.3 GaConsiderable evidence points to a Martian origin of the SNC meteorites. One of these meteorites, Nakhla, contains a leachable component which has an elevated Xe-129/Xe-132 ratio relative to its Kr-84/Xe-132 ratio when compared to the approximately linear array defined by Chassigny, most shergottites, and lithology C of EETA 79001. This array is thought to be a mixing line between Martian mantle and Martian atmosphere. 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 C. The radiogenic Xe component may represent a distinct reservoir in the Martian crust or mantle. More plausibly, it is Martian atmosphere, fractionated by solution in liquid water and by interaction with sediment. The crystallization age of Nakhla is 1.3 Ga. Its low shock state suggests that it was ejected from near the surface of Mars. Liquid water is required for the formation of iddingsite. These observations provide further evidence for the near surface existence of aqueous fluids more recently than 1.3 Ga.
Drake, Michael J. (Arizona Univ. Tucson, AZ, United States)
Owen, Toby (Hawaii Univ. Manoa., United States)
Swindle, Timothy (Arizona Univ. Tucson, AZ, United States)
Musselwhite, Donald (Arizona Univ. Tucson, AZ, United States)
September 6, 2013
January 1, 1993
Publication: Lunar and Planetary Inst., Twenty-fourth Lunar and Planetary Science Conference. Part 1: A-F
LUNAR AND PLANETARY EXPLORATION
Work of the US Gov. Public Use Permitted.
IDRelationTitle19940007055Analytic PrimarySixth Annual Workshop on Space Operations Applications and Research (SOAR 1992), volume 219940007543Analytic PrimaryTwenty-fourth Lunar and Planetary Science Conference. Part 1: A-Fvisibility_off