Precise radiocarbon dating of charred materials on potsherds by means of their characterization

1.陶片炭化物的稳定同位素研究陶片炭化物的δ ~（13）C值约为-26 ‰，具有典型的陆源特征。该样品与考古观察结果吻合较好。δ ~（13）C值较高的样品可能受到低C/N比和δ ~（15）N分馏的海相来源的影响。个别样品的δ-13 C值与放射性碳测年结果一致，表明炭化物来源于C4植物，如谷子.日本列岛北方出土陶片中炭化物的放射性碳测年在北海道岛和东北北方地区出土的样品中，δ ~（13）C值通常为中等（约100）。-24/mil）和高C/N比，放射性碳年龄比预期的要大。海洋哺乳动物不可能是这种烧焦物质的来源，而化石燃料的使用，例如泥炭，可能是。炭化物的表征对炭化物进行了GC-MS和FT-IR测试，但这些测试并不成功。样品中挥发性物质的提取和化学预处理方法有待改进。另一方面，稳定同位素测量将是一个很好的工具，估计陶器上的炭化物的来源。

1. Stable isotope research of charred materials on potsherdsMost of charred materials on potsherds showed typical land source, about -26 per mil of delta-13C value. Such sample was in good agreement with archaeological observation. Samples with higher delta-13C value might be affected by marine source of a low C/N ratio and fractionated delta-15N. Few sample showed much higher delta-13C value with coincide radiocarbon date, indicating that the charred material was derived from C4 plant such as millet.2. Radiocarbon dating of charred material on potsherds excavated in northern part of Japanese archipelagoSamples excavated in Hokkaido Island and northern Tohoku region often show moderate delta-13C value (ca. -24 per mil) and high C/N ratio with older radiocarbon age than expected. Marine mammals cannot be the source of such charred material, while usage of fossil fuel, peat for instance, might be likely.3. Characterization of charred materialGC-MS and FT-IR measurement were carried out on charred materials, however these were not successful. The extraction of volatiles from sample and chemical pretreatment should be improved. On the other hand, stable isotope measurement will be a good tool for estimation of the source of charred materials on pottery.