title: Homogeneous distribution of 26Al in the solar system from the Mg isotopic composition of chondrules.
abstract: The timing of the formation of the first solids in the solar system remains poorly constrained. Micrometer-scale, high-precision magnesium (Mg) isotopic analyses demonstrate that Earth, refractory inclusions, and chondrules from primitive meteorites formed from a reservoir in which short-lived aluminum-26 (26Al) and Mg isotopes were homogeneously distributed at +/-10%. This level of homogeneity validates the use of 26Al as a precise chronometer for early solar system events. High-precision chondrule 26Al isochrons show that several distinct chondrule melting events took place from approximately 1.2 million years (My) to approximately 4 My after the first solids condensed from the solar nebula, with peaks between approximately 1.5 and approximately 3 My, and that chondrule precursors formed as early as 0.87(-0.16)(+0.19) My after.
authors.affiliation: Centre de Recherches Petrographiques et Geochimiques (CRPG)-Nancy Université-CNRS, UPR 2300, 15 Rue Notre-Dame des Pauvres, Boite Postale 20, 54501 Vandoeuvre-lès-Nancy, France. johanv@crpg.cnrs-nancy.fr
authors.forename: Johan
authors.initials: J
authors.lastname: Villeneuve
authors.forename: Marc
authors.initials: M
authors.lastname: Chaussidon
authors.forename: Guy
authors.initials: G
authors.lastname: Libourel