Noble gas adsorption with and without mechanical stress: Not Martian signatures but fractionated air

摘要: Sample preparation, involving physical and chemical methods, is an unavoidable step in geochemical analysis. From a noble gas perspective, the two important effects are loss of sample and/or incorporation air, which significant sources analytical artifacts. This article reports on exposure to laboratory air without mechanical influence during grinding. The experiments include pure adsorption terrestrial analog materials (gibbsite olivine) grinding Martian meteorites. A consistent observation presence elementally fractionated component samples studied. critical form contamination meteorites as it often mimics heavy signatures known extra-terrestrial end-members that basis conclusions about origin evolution meteorite. Although such can be minimized by avoiding elaborate preparation protocols, caution should exercised interpreting elemental ratios (Ar/Xe, Kr/Xe), especially low-temperature extractions. also transferred investigation with long residence times, Mars, where Mars Science Laboratory mission will able measure current atmosphere rocks soils collected surface Gale crater.