Isotopic evidence of dietary variations and weaning practices in the Gaya cemetery at Yeanri, Gimhae, South Korea.

Stable carbon and nitrogen isotope analyses were conducted to investigate dietary variation in human skeletons (n = 109) from the Gaya cemetery at Yeanri located near Gimhae City, South Korea. The cemetery contained three distinct grave types dating to 4th-7th century AD. The main purposes of this research were to reconstruct palaeodiet in the Gaya population and to explore correlations between stable isotope compositions and burial types, inferred age, and sex of these individuals. The isotopic data indicate that the people at Yeanri consumed a predominantly C(3)-based terrestrial diet supplemented with freshwater and/or marine resources. The comparison of isotopic results reveals significant differences in delta(13)C values among three adult burial types (wood-cist coffin: -18.5 +/- 0.5 per thousand, stone-cist coffin: -18.1 +/- 0.6 per thousand, mausoleum: -17.8 +/- 0.9 per thousand). Males in wood-cist and stone-cist coffins have relatively more elevated mean delta(13)C and delta(15)N values than females. The isotopic ratios from the two adult age groups (21-40 years and 40-60 years) indicate that there was no significant dietary change in individuals with age. The isotope data from the infants and children suggest the weaning was a gradual process that was completed between 3 and 4 years of age in the Gaya population. This evidence indicates that the dietary variations within the cemetery reflect social status, sex, and childhood consumption patterns.