The origin of metal and chondrules in CH and CB chondrites – Evidence from Fe, Ni, and Mg isotopes

The formation of metal aggregates and chondrules in undifferentiated meteorites is discussed controversially. For the metal-rich CH and CB chondrites two possible formation scenarios are being considered. One scenario is the formation of at least some metals by  direct condensation from the solar nebular and in the other scenario metal and chondrules formed by condensation from a gas phase that was generated as a result of the collision of planetesimals in the early solar nebular. In order to reconstruct the origin of the metal aggregates and potentially the formation of chondrules in these chondrites we will conduct in situ isotope (Fe, Ni, and Mg) and trace element analyses by femtosecond laser ablation MC-ICP-MS. We expect the outcome of coupled trace element and isotopic results, in particular of the zoned aggregates, to provide information on 1) the conditions during condensation and accretion of the parent bodies and (2) whether these metal-rich chondrites originate from one and the same- or from different parent bodies. With this information, we aim to contribute towards a better understanding of early Solar System processes, including accretion and planet formation.