Precise determination of Barium isotopes and its application to planetary materials

Abstract

The Cs-135 and Ba-135 isotopic system has been interested to give us time-scales of alkali metal differentiation of planetary materials in the early solar sytem. However, except a few cases, reports of precise Ba isotopic analyses for planetary materials have been quite limited. We have developed a precision technique of Ba isotopes (precisions of about several ppm), and found for the first case the excess in Ba-135 for a carbonaceous chondrite. We report here results for carbonaceous and ordinary chondrites, as well as standard rocks and reagents.