Isotopic analyses of barium in meteorites and in terrestrial samples

Isotopic composition and concentration of barium in six stone meteorites and the silicate inclusions of two iron meteorites and three terrestrial samples were measured by use of a ‘double spike’ isotopic dilution technique in order to correct for laboratory fractionation. Any differences between the abundances of the isotopes in meteoritic and terrestrial Ba were found to be less than 0. 1% for all isotopes. The per cent abundances of Ba found in our work for Ba^ (138), Ba^ (137), Ba^ (136), Ba^ (135), Ba^ (134), Ba^ (132), and Ba^ (130) are 71. 699, 11. 232, 7. 853, 6. 592, 2. 417, 0. 1012, and 0. 1058, respectively. Because of the higher precision, these abundances should replace the currently accepted values. These results show the variations in the Ba isotopes reported by S. Umemoto (1962) to be unsubstantiated.