Noble gas studies in CAIs from CV3 chondrites: No evidence for primordial noble gases

Noble Gases in Allende Fluffy and Compact Cais

The Ne and Ar isotopic composition of Allende CAIs can consistently be explained by cosmogenically produced Ne and Ar. Thereby, the extraordinary chemistry of CAIs and the large preatmospheric size of Allende, which may cause significant cosmogenic production of Ar from Cl, were taken into account. In contrast to earlier workers, we conclude that no trapped noble gas components are needed to ex...

Primordial Noble Gas in the Earth

Noble Gases in the Nwa 852/801 Cr2 Chondrites

Introduction: North West Africa (NWA) 852 and 801 are classified as CR2 chondrites [1-2]. The two meteorites contain relatively large chondrules (1-2 mm in diameter), FeNi metal, and dark inclusions composed of serpentine and olivine. We measured noble gases in the two meteorites with stepwise heating, which facilitates decomposition of noble gas components with different origins and trapping s...

Metamorphic Control of Noble Gas Abundances in Pristine Chondrites

Introduction: One of the most enduring enigmas of meteoritics is the nature of the Q (or P1) phase carrier with its associated trapped "planetary Q-gases" (He, Ne, Ar, Kr and Xe), defined by [1]. Many evidences suggest the Q-phase carrier is carbonaceous [e.g. 2], but the location of noble gas atoms in the carbon network has not been yet identified. Among the suggested structural forms of Q-pha...

Noble gases in mantle plumes.

Trieloff et al. (1) provided neon isotope data to argue that mantle neon originates as a trapped component in meteorites rather than having a pristine solar composition. That finding, if true, has important consequences for understanding the mechanism of volatile input into the mantle, because it rules out models involving direct incorporation of solar gases. The main argument that Trieloff et ...