Dating of meteoritic carbonates...

[David Entwistle]

Working at the The University of Tokyo, Wataru Fujiya, Naoji Sugiura, Hideyuki Hotta, Koji Ichimura and Yuji Sano have published a paper detailing their work to refine the age of the carbonate grains in carbonaceous chondrite meteorites. The paper is titled: Evidence for the late formation of hydrous asteroids from young meteoritic carbonates.

Abstract

We improved a method for the dating of meteoritic carbonate grains, and determined accurate ages for several carbonate grains in four meteorites. Carbonates in primitive meteorites formed in asteroids and dating them tells us when hydrous asteroids formed.

The results for these carbonates converged on an age of 4563.4 million years ago, which is younger than previous estimates for these same meteorites. We interpret this to mean a late onset of aqueous activities in the Solar System. This new younger carbonate age suggests that the parent asteroid formed 3.5 million years after the birth of the Solar System.

Further information:

University of Tokyo press release.
Nature online abstract.

Meteorites:

Murchison
Yamato 791198
Allan Hills 83100
Sayama