Research Article

Supra-Canonical 26Al/27Al and the Residence Time of CAIs in the Solar Protoplanetary Disk

See allHide authors and affiliations

Science  08 Apr 2005:
Vol. 308, Issue 5719, pp. 223-227
DOI: 10.1126/science.1108140

You are currently viewing the abstract.

View Full Text

Log in to view the full text

Log in through your institution

Log in through your institution

Abstract

The canonical initial 26Al/27Al ratio of 4.5 × 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 105-year residence time in the solar protoplanetary disk.

View Full Text