Cosmogenic 45Sc in Gibeon iron meteorite by radioanalytical neutron activation analysis
Abstract Cosmogenic nuclides in many fragments of Gibeon iron meteorite have been studied by Honda and co-workers. They observed that their concentrations varied by 5 orders and found that Gibeon gives two different exposure ages using pair of stable noble gas isotopes and radinuclide. To assess one possible cause for the difference, namely loss of partial noble gases due to atmospheric heating of the incoming meteoroid, concentrations of non-volatile and stable cosmogenic 45Sc of Gibeon were determined by radiochemical neutron activation analysis (RNAA). For RNAA, a radiochemical procedure using extraction chromatography was developed to separate Sc from an iron meteorite. Concentrations of 45Sc in 7 fragments ranged from 0.0064 to 0.11 ppb and correlated with cosmogenic 4He concentrations. This correlation suggests that noble gases in Gibeon were not lost during the fall to the earth.
