The platinum-group elements (PGEs; Os, Ir, Ru, Rh, Pt, Pd), along with rhenium and gold, are grouped together as the highly siderophile elements (HSEs), defined by their extreme partitioning into the metallic, relative to the oxide phase (> 104). The HSEs are highly refractory, as gauged by their high melting and condensation temperatures, and were therefore relatively concentrated in the feedstock for the terrestrial planets, as defined by the composition of chondritic meteorites (e.g., Anders and Ebihara 1982; Horan et al. 2003; Fischer-Gödde et al. 2010). However, the planetary formation and differentiation process has since...

First Page Preview

First page PDF preview
You do not currently have access to this article.