Rhenium and Osmium Abundances in Stony Meteorites

Abstract

Neutron activation measurements of rhenium and osmium abundances in the Orgueil, Mokoia, Karoonda, Mocs, and Hvittis chondrites indicate no fractionation of these elementsbetween the various chondrite types. The average abundances in chondritic material are RE = 60.3 X 10^-9g/g and Os =710 X 10^-9g/g (Os/ Re = 11.5). The rhenium abundance in the Bishopville enstatite achondrite is about 1/300 as much, and the osmium abundances about 1/100 as much, as theabundances in parental enstatite chondrites, indicating that most of the rhenium and osmium in the enstatite chondrites is in the metallic phase.