Oxygen isotope variation in stony-iron meteorites.
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.
Greenwood
R C
RC
Planetary and Space Sciences Research Institute, Open University, Walton Hall, Milton Keynes, MK7 6AA UK. r.c.greenwood@open.ac.uk
Franchi
I A
IA
Jambon
A
A
Barrat
J A
JA
Burbine
T H
TH
D019419:Evolution, Planetary; D019110:Meteoroids; D018543:Minor Planets; D010103:Oxygen Isotopes
D010103:Oxygen Isotopes