RELATIVE ABUNDANCES OF ARGON, KRYPTON, AND XENON IN THE MARTIAN ATMOSPHERE AS MEASURED IN MARTIAN METEORITES

We determined the concentrations of trapped Ar, Kr, and Xe in impact-m elt glasses from Shergotty, Y793605, and two inclusions of EET79001 no t previously analyzed. When combined with literature noble gas data on a single glass inclusion in EET79001 and a glass vein in Zagami, thes e data give more accurate estimates of the composition of Martian atmo spheric gases trapped in these glasses. For the geological recent comp osition of the Martian atmospheric we infer Xe-129/Xe-132 = 2.60 +/- 0 .05, Ar-36/Xe-132 = 900 +/- 100, and Kr-84/Xe-132 = 20.5 +/- 2.5. Thes e elemental ratios differ from those measured by Viking by factors of 2.5 and 1.8, respectively. The Ar-36/Xe-132 and Kr-84/Xe-132 ratios in ALH84001 are considerably less than those in impact glasses and sugge st preferential adsorption tin carbonate?) of Xe over Ar and Xe over K r by factors of similar to 11 and similar to 2.6, respectively. We sug gest that noble gases dissolved in water may have largely determined t he trapped noble gas abundance pattern in ALH84001. Copyright (C) 1998 Elsevier Science Ltd.