Bidong Zhang¹, Nancz L. Chabot¹ and Alan E. Rubin¹
Science Advances – Link to Article [https://www.science.org/doi/full/10.1126/sciadv.abo5781]
¹Department of Earth, Planetary and Space Sciences, University California, Los Angeles, CA 90095-1567, USA.
²Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA.
Copyright Elsevier

The parent cores of iron meteorites belong to the earliest accreted bodies in the solar system. These cores formed in two isotopically distinct reservoirs: noncarbonaceous (NC) type and carbonaceous (CC) type in the inner and outer solar system, respectively. We measured elemental compositions of CC-iron groups and used fractional crystallization modeling to reconstruct the bulk compositions and crystallization processes of their parent asteroidal cores. We found generally lower S and higher P in CC-iron cores than in NC-iron cores and higher HSE (highly siderophile element) abundances in some CC-iron cores than in NC-iron cores. We suggest that the different HSE abundances among the CC-iron cores are related to the spatial distribution of refractory metal nugget–bearing calcium aluminum–rich inclusions (CAIs) in the protoplanetary disk. CAIs may have been transported to the outer solar system and distributed heterogeneously within the first million years of solar system history.