The protoplanetary disk and the complementarity red herring
Intervenant : Brigitte Zanda
Muséum national d'Histoire naturelle, Paris
Primitive meteorites (chondrites) are made of high-temperature constituants (chondrules) assembled with low-temperature fine-grained material (matrix) over 4.5 Ga ago in the protoplanetary disk. What do these rocks tell us about the workings of the disk and the genesis of the first planetary bodies? There is an ongoing debate as to whether chondrules and matrix are "complementary" to one another in a given chondrite (that is, formed and assembled from a unique reservoir of solar composition), or whether these components formed independently and may have been transported over long distances before the chondrite accreted. Recent isotopic results are being used to support the "complementarity" hypothesis, but they prove that chondrules and matrix formed from distinct isotopic reservoirs.