Moving peoples, changing diets: isotopic differences highlight migration and subsistence changes in the Upper Mun River Valley, Thailand

Abstract

The dramatic growth of dietary isotope studies in archaeological literature attests to the significant potential this technique has for shedding light on past societies. Human diet reflects complex, inter-linked factors such as status, cultural preferences or environmental constraints on food production. In this study dietary isotope analysis is used to examine the human skeletal remains from Ban Non Wat, northeast Thailand. The study aims to use isotopic data to give insight into patterns of migration and subsistence strategy during prehistory. Ban Non Wat is the most comprehensively excavated site in the Upper Mun River Valley (UMRV), and understanding of prehistoric society in this area is crucial to answering questions of how social complexity arose in the region. Carbon isotope analysis has highlighted migrant individuals invisible to strontium isotope analysis and shown links between unusual burial practice and differences in diet. Results also indicate that diet changed substantially through time, with more reliance on rice in the Bronze Age, correlated with an increase in social differentiation. There is a move away from reliance on rice agriculture in the Iron Age, a time when oxygen isotopes show that environmental conditions were becoming drier, possibly resulting in rice agriculture becoming less viable.