Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Published Online March 3, 2005
Science DOI: 10.1126/science.1108140

Research Articles

Submitted on December 1, 2004
Accepted on February 11, 2005

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

Edward D. Young 1*, Justin I. Simon 2, Albert Galy 3, Sara S. Russell 4, Eric Tonui 2, Oscar Lovera 2

1 Institute of Geophysics and Planetary Physics, UCLA, Los Angeles, CA, USA; Department of Earth and Space Sciences, UCLA, Los Angeles, CA, USA.
2 Department of Earth and Space Sciences, UCLA, Los Angeles, CA, USA.
3 Department of Earth Sciences, University of Cambridge, Cambridge, UK.
4 The Natural History Museum, London, UK.

* To whom correspondence should be addressed.
Edward D. Young , E-mail: eyoung{at}ess.ucla.edu

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 MC-ICPMS Mg isotope analyses of calcium-aluminum-rich inclusions 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 can not 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.


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Homogeneous Distribution of 26Al in the Solar System from the Mg Isotopic Composition of Chondrules.
J. Villeneuve, M. Chaussidon, and G. Libourel (2009)
Science 325, 985-988
   Abstract »    Full Text »    PDF »
Isotopes as clues to the origin and earliest differentiation history of the Earth.
S. B Jacobsen, M. C Ranen, M. I Petaev, J. L Remo, R. J O'Connell, and D. D Sasselov (2008)
Phil Trans R Soc A 366, 4129-4162
   Abstract »    Full Text »    PDF »
Oxygen Isotopes of Chondritic Components.
H. Yurimoto, A. N. Krot, B.-G. Choi, J. Aleon, T. Kunihiro, and A. J. Brearley (2008)
Reviews in Mineralogy and Geochemistry 68, 141-186
   Abstract »    Full Text »    PDF »
The Formation of the Solar System.
S. S. Russell (2007)
Journal of the Geological Society 164, 481-492
   Abstract »    Full Text »    PDF »


To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)