[H-TT15] Development and application of environmental traceability methods

[HTT15-09] Carbon and nitrogen isotope analysis on human skeletal remains of Tsukumo shell mound of Okayama Prefecture.

*Soichiro Kusaka¹, Masashi Maruyama¹ (1.Tokai University)

Keywords:Jomon, Human bone

Many human skeletal remains from the Middle to Final Jomon period have been excavated from the Tsukumo Shell Mound in Kasaoka City, Okayama Prefecture. The site is famous for being the first place in Japan where a large number of human skeletal remains of the Jomon period were discovered after excavations were conducted in the Taisho era. Research of the burial posture, grave goods, and ritual tooth ablation customs among Tsukumo has played a major role in reconstructing the social structure of the Jomon period. The dietary reconstruction and age of the skeletal remains have been clarified by carbon and nitrogen isotope analysis and radiocarbon dating of materials in the Kyoto University collection. In this study, we examined materials from the Osaka University collection, the details of which have not yet been reported. We performed carbon and nitrogen isotope analysis to reconstruct their dietary characteristics. The materials consisted of a total of 47 samples of archaeological human skeletal remains excavated from the Tsukumo shell mound. We selected the materials from which we could determine sex and age, extracted bone collagen, and measured carbon and nitrogen isotope ratios. The results showed large variations in carbon and nitrogen isotope ratios, indicating a diet combining marine and terrestrial resources and individual differences in diet. Compared to previous data from the Kyoto University collection, the nitrogen isotope ratios tended to be higher. Previous studies have revealed that nitrogen isotope ratios in the Sanyo area tended to decrease from the Middle to Final Jomon period. Considering this, it was suggested that the Osaka University materials may have belonged to the Middle to Late Jomon period. It is possible that a large number of ancient human bones were buried in the Tsukumo shell mound from the Middle to Final Jomon Period, but radiocarbon dating is needed to determine the age of the human skeletal remains.