title: Oxygen isotope variation in stony-iron meteorites.
abstract: Asteroidal material, delivered to Earth as meteorites, preserves a record of the earliest stages of planetary formation. High-precision oxygen isotope analyses for the two major groups of stony-iron meteorites (main-group pallasites and mesosiderites) demonstrate that each group is from a distinct asteroidal source. Mesosiderites are isotopically identical to the howardite-eucrite-diogenite clan and, like them, are probably derived from the asteroid 4 Vesta. Main-group pallasites represent intermixed core-mantle material from a single disrupted asteroid and have no known equivalents among the basaltic meteorites. The stony-iron meteorites demonstrate that intense asteroidal deformation accompanied planetary accretion in the early Solar System.
authors.affiliation: Planetary and Space Sciences Research Institute, Open University, Walton Hall, Milton Keynes, MK7 6AA UK. r.c.greenwood@open.ac.uk
authors.forename: R C
authors.initials: RC
authors.lastname: Greenwood
authors.forename: I A
authors.initials: IA
authors.lastname: Franchi
authors.forename: A
authors.initials: A
authors.lastname: Jambon
authors.forename: J A
authors.initials: JA
authors.lastname: Barrat
authors.forename: T H
authors.initials: TH
authors.lastname: Burbine
mesh_terms: D019419:Evolution, Planetary; D019110:Meteoroids; D018543:Minor Planets; D010103:Oxygen Isotopes
chemical_list: D010103:Oxygen Isotopes