Isotopic homogeneity of iron in the early solar nebula.

摘要: The chemical and isotopic homogeneity of the early solar nebula, processes producing fractionation during its evolution, are central issues cosmochemistry. Studies relative abundance variations three or more isotopes an element can in principle determine if initial reservoir material was a homogeneous mixture it contained several distinct sources precursor material. For example, widespread anomalies1,2,3,4 observed oxygen meteorites have been interpreted as resulting from mixing solid phase that enriched 16O with gas which depleted1,2,3, ‘memory’ Galactic evolution5. In either case, these anomalies regarded strong evidence nebula not initially homogeneous. Here we present measurements abundances iron meteoritic terrestrial samples. We show significant exist both extraterrestrial materials. But when plotted three-isotope diagram, all data for Solar System materials fall on single mass-fractionation line, showing homogenization occurred before planetesimal accretion chondrule formation.