Osmium abundances and their correlation with iridium in some geological boundaries

Until now, the study of elemental abundances in geological boundaries mainly lies in iridium. In contrast, very little work on abundance anomaly of osmium and other platinum group elements has been done. Based on the similarity of inorganic and geochemical behaviors of Os to those of Ir, one may think that the Os anomaly should exist in the boundaries showing the Ir anomaly. Further, the correlation of Os with Ir can be served as a criteria to distinguish the origin of the abundance anomaly of the platinum group elements. Thus, the authors developed a sophisticated procedure of radiochemical separation combined with NAA, and determined the Os abundances of some important geological boundaries