Oxygen isotope systematics of chondrule olivine, pyroxene, and plagioclase in one of the most pristine CV3_Red chondrites (Northwest Africa 8613).

ABSTRACT: We performed in situ oxygen three-isotope measurements of chondrule olivine, pyroxenes, and plagioclase from the newly described CV_Red chondrite NWA 8613. Additionally, oxygen isotope ratios of plagioclase in chondrules from the Kaba CV3_OxB chondrite were determined to enable comparisons of isotope ratios and degree of alteration of chondrules in both CV lithologies. NWA 8613 was affected by only mild thermal metamorphism. The majority of oxygen isotope ratios of olivine and pyroxenes plot along a slope-1 line in the oxygen three-isotope diagram, except for a type II and a remolten barred olivine chondrule. When isotopic relict olivine is excluded, olivine, low- and high-Ca pyroxenes are indistinguishable regarding Δ¹⁷O values. Conversely, plagioclase in ch

SUBMITTER: Hertwig AT 

PROVIDER: S-EPMC7121232 | biostudies-literature | 2019 Nov

REPOSITORIES: biostudies-literature