2013 年 47 巻 3 号 p. 139-147
After finishing the Ph.D. course at University of Tokyo in 1979, I started my research carrier as a research associate to Professor Edward Anders at the Enrico Fermi Institute of University of Chicago. During a two and a half years stay in Chicago, I engaged in neutron activation analysis (NAA) of lunar samples and meteorites for the first half term and then switched the research subject to noble gas mass-spectrometry. Based on NAA of CI chondrites, two papers were published in 1982, one of which is focused on the elemental fractionation in CI chondrites. We confirmed two types of fractionation caused by either aqueous activity on the CI chondrite parent body or nebular processes (possibly condensation). Another paper was entitled "Solar-system abundances of the elements". Here, I reviewed these two papers and presented several significant characteristics observed in the elemental abundances of CI chondrites.
