Cosmogenic nitrogen isotopic disequilibrium observed in meteorites

Abstract

Abstract— The isotopic disequilibrium of N molecules in meteorites was examined. For a large data‐set, consisting of mass compositions of N molecules extracted at 1200 °C by stepped combustion of chondrites and eucrites, we find that a cosmogenic‐N‐enriched component and a normal air‐like N component are isotopically disequilibrated with each other. The isotopic composition of the cosmogenic‐N‐enriched component seems to be variable, although the cause for the variation is not clear. The abundance of indigenous atomic N in silicate minerals seems to be small. Indigenous N in meteoritic silicates, if present, may be present in the form of N molecules.