INTERNATIONAL UNION OF PURE AND APPLIED CHEMISTRY INORGANIC CHEMISTRY DIVISIOI COMMISSION ON ATOMIC WEIGHTS AND ISOTOPIC ABUNDANCES* SUBCOMMITTEE FOR ISOTOPIC ABUNDANCE MEASUREMENTS *N ISOTOPIC COMPOSITIONS OF THE ELEMENTS 1997 by KJR ROSMAN AND PDP TAYLOR2 Department of Applied Physics, Curtin University of Technology, GPO Box U1987, Perth 6001