title: The formation of chondrules at high gas pressures in the solar nebula.
abstract: High-precision magnesium isotope measurements of whole chondrules from the Allende carbonaceous chondrite meteorite show that some aluminum-rich Allende chondrules formed at or near the time of formation of calcium-aluminum-rich inclusions and that some others formed later and incorporated precursors previously enriched in magnesium-26. Chondrule magnesium-25/magnesium-24 correlates with [magnesium]/[aluminum] and size, the aluminum-rich, smaller chondrules being the most enriched in the heavy isotopes of magnesium. These relations imply that high gas pressures prevailed during chondrule formation in the solar nebula.
authors: Department of Earth Sciences, University of Oxford, Parks Road, Oxford, OX1 3PR, UK. albert00@esc.cam.ac.uk
authors: A
authors: A
authors: Galy
authors: E D
authors: ED
authors: Young
authors: R D
authors: RD
authors: Ash
authors: R K
authors: RK
authors: O'Nions