Early formation of planetary building blocks inferred from Pb isotopic ages of chondrules

Jean Bollard (1) , James N Connelly (1) , Martin Whitehouse (2) , Emily Pringle (3) , Lydie Bonal (4) , Jes K. Jorgensen (1) , Åke Nordlund (1) , Frédéric Moynier (3) , Martin Bizzarro (3, 1)

1 UCPH - University of Copenhagen = Københavns Universitet
2 Laboratory for Isotope Geology
3 IPGP (UMR_7154) - Institut de Physique du Globe de Paris
4 IPAG - Institut de Planétologie et d'Astrophysique de Grenoble

The most abundant components of primitive meteorites (chondrites) are millimeter-sized glassy spherical chondrules formed by transient melting events in the solar protoplanetary disk. Using Pb-Pb dates of 22 individual chondrules, we show that primary production of chondrules in the early solar system was restricted to the first million years after the formation of the Sun and that these existing chondrules were recycled for the remaining lifetime of the protoplanetary disk. This finding is consistent with a primary chondrule formation episode during the early high-mass accretion phase of the protoplanetary disk that transitions into a longer period of chondrule reworking. An abundance of chondrules at early times provides the precursor material required to drive the efficient and rapid formation of planetary objects via chondrule accretion.

Domaines: Planétologie et astrophysique de la terre [astro-ph.EP]

Jean Bollard, James N Connelly, Martin Whitehouse, Emily Pringle, Lydie Bonal, et al.. Early formation of planetary building blocks inferred from Pb isotopic ages of chondrules. Science Advances , 2017, 3 (8), pp.e1700407. ⟨10.1126/sciadv.1700407⟩. ⟨insu-02594149⟩