Formation of chondrules in a moderately high dust enriched disk: Evidence from oxygen isotopes of chondrules from the Kaba CV3 chondrite

Investigation of the Mg#-Δ17O relationship revealed that Δ17O values tend to increase with decreasing Mg#'s, similar to those observed for CR chondrites though data from Kaba cluster at the high Mg# (>98) and the low Δ17O end (−6‰ and −4‰). A mass balance model involving 16O-rich anhydrous dust (Δ17O = −8‰) and 16O-poor water ice (Δ17O = +2‰) in the chondrule precursors suggests that type I chondrules in Kaba would have formed in a moderately high dust enriched protoplanetary disk at relatively dry conditions (∼50-100× dust enrichment compared to Solar abundance gas and less than 0.6× ice enhancement relative to CI chondritic dust). The olivine-rich type II chondrule probably formed in a disk with higher dust enrichment (∼2000× Solar).