MetadataShow full item record
CitationPatzer, A., & Schultz, L. (2002). Noble gases in enstatite chondrites II: The trapped component. Meteoritics & Planetary Science, 37(4), 601-612.
PublisherThe Meteoritical Society
JournalMeteoritics & Planetary Science
AbstractThe trapped noble gas record of 57 enstatite chondrites (E chondrites) has been investigated. Basically, two different gas patterns have been identified dependent on the petrologic type. All E chondrites of type 4 to 6 show a mixture of trapped common chondritic rare gases (Q) and a subsolar component (range of elemental ratios for E4-6 chondrites: 36Ar/132Xe = 582 +/- 270 and 36Ar/84Kr = 242 +/- 88). E3 chondrites usually contain Q gases, but also a composition with lower 36Ar/132Xe and 36Ar/84Kr ratios, which we call sub-Q (36Ar/132Xe = 37.0 +/- 18.0 and 36Ar/84Kr = 41.7 +/- 18.1). The presence of either the subsolar or the sub-Q signature in particular petrologic types cannot be readily explained by parent body metamorphism as postulated for ordinary chondrites. We therefore present a different model that can explain the bimodal distribution and composition of trapped heavy noble gases in E chondrites. Trapped solar noble gases have been observed only in some E3 chondrites. About 30% of each group, EH3 and EL3 chondrites, amounting to 9% of all analyzed E chondrites show the solar signature. Notably, only one of those meteorites has been explicitly described as a regolith breccia.