title: Supra-canonical 26Al/27Al and the residence time of CAIs in the solar protoplanetary disk.
abstract: The canonical initial 26Al/27Al ratio of 4.5 x 10(-5) has been a fiducial marker for the beginning of the solar system. Laser ablation and whole-rock multiple-collector inductively coupled plasma-source mass spectrometry magnesium isotope analyses of calcium- and aluminum-rich inclusions (CAIs) from CV3 meteorites demonstrate that some CAIs had initial 26Al/27Al values at least 25% greater than canonical and that the canonical initial 26Al/27Al cannot mark the beginning of solar system formation. Using rates of Mg diffusion in minerals, we find that the canonical initial 26Al/27Al is instead the culmination of thousands of brief high-temperature events incurred by CAIs during a 10(5)-year residence time in the solar protoplanetary disk.
authors.affiliation: Institute of Geophysics and Planetary Physics, University of California-Los Angeles, Los Angeles, CA 90095, USA. eyoung@ess.ucla.edu
authors.forename: Edward D
authors.initials: ED
authors.lastname: Young
authors.forename: Justin I
authors.initials: JI
authors.lastname: Simon
authors.forename: Albert
authors.initials: A
authors.lastname: Galy
authors.forename: Sara S
authors.initials: SS
authors.lastname: Russell
authors.forename: Eric
authors.initials: E
authors.lastname: Tonui
authors.forename: Oscar
authors.initials: O
authors.lastname: Lovera