Abstract
New radiocarbon determinations from rice grains and bamboo have been obtained from Non Ban Jak, Northeast Thailand. These, along with charcoal, date a late Iron Age building sequence. The results come from short‐lived species and charcoal with potential inbuilt age. We built a series of Bayesian models to obtain a reliable chronology. A model including a Charcoal_Plus Outlier detection approach can allow us to include charcoal dates, which are almost certainly affected by inbuilt age and quantify the effect. The results demonstrate that the site accumulated very rapidly within the 5th century ce , a chronological framework with important cultural implications.