Oxygen isotope systematics of chondrules in the Paris CM2 chondrite: indication for a single large formation region across snow line.

In-situ oxygen three-isotope analyses of chondrules and isolated olivine grains in the Paris (CM) chondrite were conducted by secondary ion mass spectrometry (SIMS). Multiple analyses of olivine and/or pyroxene in each chondrule show indistinguishable ΔO values, except for minor occurrences of relict olivine grains (and one low-Ca pyroxene). A mean ΔO value of these homogeneous multiple analyses was obtained for each chondrule, which represent oxygen isotope ratios of the chondrule melt.

Oxygen isotope systematics of chondrule olivine, pyroxene, and plagioclase in one of the most pristine CV3 chondrites (Northwest Africa 8613).

We performed in situ oxygen three-isotope measurements of chondrule olivine, pyroxenes, and plagioclase from the newly described CV chondrite NWA 8613. Additionally, oxygen isotope ratios of plagioclase in chondrules from the Kaba CV3 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 Al-Mg systematics of FeO-rich chondrules from Acfer 094: two chondrule generations distinct in age and oxygen isotope ratios.

The Al-Mg ages of FeO-rich (type II) chondrules from Acfer 094, one of the least thermally metamorphosed carbonaceous chondrites, were determined by SIMS analysis of plagioclase and olivine/pyroxene using a radio frequency (RF) plasma oxygen ion source. In combination with preexisting Al-Mg ages of FeO-poor (type I) chondrules, the maximum range of formation ages recorded in chondrules from a single meteorite is determined to help provide constraints on models of material transport in the proto-planetary disk. We also report new SIMS oxygen three-isotope analyses of type II chondrules in Acfer 094.

A Coordinated Microstructural and Isotopic Study of a Wark-Lovering Rim on a Vigarano CAI.

We carried out a coordinated mineralogical and isotopic study of a Wark-Lovering (WL) rim on a Ca,Al-rich inclusion (CAI) from the reduced CV3 chondrite Vigarano. The outermost edge of the CAI mantle is mineralogically and texturally distinct compared to the underlying mantle that is composed of coarse, zoned melilite (Åk) grains. The mantle edge contains fine-grained gehlenite with hibonite and rare grossite that likely formed by rapid crystallization from a melt enriched in Ca and Al.

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

Oxygen three-isotope analysis by secondary ion mass spectrometry of chondrule olivine and pyroxene in combination with electron microprobe analysis were carried out to investigate 24 FeO-poor (type I) and 2 FeO-rich (type II) chondrules from the Kaba (CV) chondrite. The Mg#'s of olivine and pyroxene in individual chondrules are uniform, which confirms that Kaba is one of the least thermally metamorphosed CV3 chondrites. The majority of chondrules in Kaba contain olivine and pyroxene that show indistinguishable ΔO values (= δO - 0.