Radiocarbon dating of seeds and a wood excavateed at Emon site

Kokubu, Yoko   ; Matsubara, Akihiro; Ishimaru, Tsuneari ; Miyake, Masayasu*; Nishizawa, Akimitsu*; Owaki, Yoshio*; Nishio, Tomohiro*

Radiocarbon dating using accelerator mass spectrometry (AMS) was performed on Gramineae spp. seeds and a wood trunk collected from layers of IVb and Vb at the trench 1 of Emon site. After counting of number of tree rings of the trunk, 5 rings containing the outermost layer and the innermost one were cut to obtain wiggle-matched calibrated ages. In JAEA-AMS-TONO, graphite were made from the seeds and the rings and then their carbon isotope ratios were measured by AMS to obtain radiocarbon date. Calendar ages were calculated from the radiocarbon dates. Calendar ages of two seeds collected from the IVb layer were ranged between century of 15 and 17. That of the outermost layer of the trunk was about 1300 calAD, which was older than those of the seeds. On the other hand, those of the seeds collected from the Vb layer were 14 century.