title: Mass-independent oxygen isotopic partitioning during gas-phase SiO2 formation.
abstract: Meteorites contain a wide range of oxygen isotopic compositions that are interpreted as heterogeneity in solar nebula. The anomalous oxygen isotopic compositions of refractory mineral phases may reflect a chemical fractionation process in the nebula, but there are no experiments to demonstrate this isotope effect during particle formation through gas-phase reactions. We report experimental results of gas-to-particle conversion during oxidation of silicon monoxide that define a mass-independent line (slope one) in oxygen three-isotope space of (18)O/(16)O versus (17)O/(16)O. This mass-independent chemical reaction is a potentially initiating step in nebular meteorite formation, which would be capable of producing silicate reservoirs with anomalous oxygen isotopic compositions.
authors.affiliation: Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093-0356, USA.
authors.forename: Subrata
authors.initials: S
authors.lastname: Chakraborty
authors.forename: Petia
authors.initials: P
authors.lastname: Yanchulova
authors.forename: Mark H
authors.initials: MH
authors.lastname: Thiemens