Chronology of the pottery assemblage excavated from a local area has been established by typological and stratigraphic analyses, by comparing shapes and surface decorations of pottery, as well as by analyzing the sequence of horizons from which the pottery fragments were excavated. The typological and stratigraphic analyses can provide a temporal but relative sequence of pottery production. To assign numerical ages to pottery samples, however, dating methods based on natural science should be applied to them. The potsherd fragments excavated from archeological sites bear frequently charred carbonaceous materials on their surfaces. We have conducted radiocarbon (14C) dating with accelerator mass spectrometry (AMS) on these carbonaceous materials. Since 14C dating with AMS requires only a few mg of carbon, charred materials can be directly dated, provided that a few milligram of carbon can be extracted after the chemical treatments to remove possible carbon contamination from them. In addition, the charred remains on the shards are one of the suitable carbonaceous samples to be measured. Since the materials would be the residues of food or soot from fuels used at the time of cocking, 14C ages of them should provide the age of pottery usage.
The purpose of this research is to provide 14C ages to pottery samples whose temporal sequence is clear in the Yayoi and the Kofun periods, and to assign definite numerical ages to the periods. We have applied 14C dating with AMS to 56 pottery samples that had been excavated from 12 archeological sites, namely, Tsukinawate, Asahi, Kadomanuma and Hachioji sites in Aichi prefecture, as well as Fujie-B, Yokaichi-jikata, Shimo-yasuhara, Higashi-matoba-takenohana, Nekohashi, Ohtomo-nishi, Ohnagano and Sendai-nomi sites in Ishikawa prefecture, central Japan. The obtained 14C ages were calibrated to calendar dates by using the INTCAL98 data sets and compared with their archeological ages. We report the calibrated AMS 14C ages of pottery samples in the Yayoi and the Kofun periods. A tendency that the calibrated 14C ages become older than respective archeological ages was obtained. The obtained numerical ages should be evaluated along with the re-examination of archeological framework of pottery chronology. In addition, the calibrated 14C ages of two pottery samples were quite consistent with relevant ages determined by dendrochronology on wood materials that were closely related with the respective pottery samples.
See more of Poster Session I
See more of The 10th International Conference on Accelerator Mass Spectrometry (September 5-10, 2005)