Oxygen Isotopic Compositions in a Plagioclase‐Olivine Inclusion from Ningqiang Similar to Those in Al‐rich Chondrules

We report the petrology and oxygen isotopic composition, using a Cameca NanoSIMS 50L ion microprobe, of plagioclase–olivine inclusion, C#1, found in Ningqiang carbonaceous chondrite. In addition to major phases (plagioclase, spinel olivine), C#1 is also surrounded by pyroxene rim (64 vol % Ca-rich 36 Ca-poor pyroxenes). On three-isotope diagram, δ17O vs. δ18O, compositions individual minerals analyzed fall along chondrite anhydrous mineral line (CCAM), show significant variability δ18O δ17O. The are similar those other host minerals, which suggests that likely formed from same melting process as host. considered have result interaction between an 16O-poor gas melt. Some grains typically 16O-rich relict origin, Ca-, Al-rich inclusions, probably precursor C#1. inclusion then melted region where chondrules form, accompanied isotope exchange with gas. anorthite, might undergone fluid-assisted thermal metamorphism on parent body. data evolution Al-chondrules chondrites.