These dates came from charcoal samples obtained from a badly disturbed context excavated by Chaplin in 1960. Phillipson and Fagan reported and revised these dates after their trial excavation in 1968 near the earlier excavated rich burials, which produced additional charcoal for radiocarbon dating.
These dates were determined through the analysis of charcoal samples obtained from a severely damaged archaeological site that Chaplin had excavated in 1960. Phillipson and Fagan later reported and updated these dates after conducting their own excavation in 1968, which uncovered additional charcoal suitable for radiocarbon dating near earlier burials of greater wealth.