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An inter-laboratory comparison of ^C dating studies with accelerator mass spectrometty (AMS) were performed between two ^C facilities, Center for Chronological Research, Nagoya University and Mutsu Office, Aomori Research and Development Center, Japan Atomic Energy Agency. Both facilities are equipped with similar types of AMS system based on 3MV tandem accelerator manufactured by High Voltage Engineering Europe (HVEE), the Netherlands, that were introduced to each laboratory almost at the same time, around in 1996-1997. Two kinds of archeological samples used for the intercomparison were offered from the Education Board of Nirasaki City, Yamanashi prefecture. One part of them was a charred rice sample with known historical age, which was collected from the ruin of Shinpu-Jyo castle remains. The rice was charred when the castle was bumt in 1582, when the castle was abandoned by the lord, Katsuyori Takeda (1546-1582) during the battle against the combined military forces of Oda and Tokugawa families. Thus it is also a critical test of accuracy of the ^C measurements on samples with known age. The other samples were charred pyrenes of peach and nutshells of Japanese walnut collected from the Shukujiri-Daini-Iseki archeological site in Nirasaki city, Yamanashi Prefecture. Totally 12 samples were shared between the two laboratories, by dividing the individual charred pyrenes and nutshells into two pieces, i.e., the shared pieces were divided from a piece of pyrene or nutshell. Thus exactly consistent ^C results are expected for the divided pieces. The results from the two AMS laboratories were quite consistent within statistical uncertainties. In addition, calibrated ^C ages for the charred rice samples were also consistent with the historical age when the Shinpu-Jyo castle was bumt down.

熊本県泉村京丈山の石灰岩洞穴より, ニホンオオカミとされるほぼ完全な1個体分の全身骨格が1976年から1977年にかけての調査で発見された, 今回, この標本と国立科学博物館所蔵のニホンオオカミ全身骨格等と骨学的な比較検討を行い, あわせて放射性炭素(^C)法を使って, 骨の年代測定を行った.本研究では, 骨試料からタンパク質であるコラーゲンを抽出し, さらに骨の有機物としてより根元的であるアミノ酸集合体を抽出し, それらの物質に含まれる炭素について, 名古屋大学に設置されているタンデトロン加速器質量分析計を用いて年代測定を実施した.その結果, 京丈山ニホンオオカミ標本はがっちりした体格のニホンオオカミであり, 全身骨格がそろった標本としては本邦2例目の最古のものであることが確認された.また, アミノ酸集合体の^C年代は380±90yrBPと得られ, 室町から江戸初期に遡る可能性が示された., タンデトロン加速器質量分析計業績報告 Summaries of Researches Using AMS 1998 (平成10)年度

Tanuki-ana Cave is a small inclined limestone cave on the Akiyoshi-dai Karst Plateau. In this cave, sediments from the cave floor to a depth of 2.4m are composed of mud with limestone breccia and muddy limestone breccia, which contain abundant vertebrate remains. The sediments are lithologically divided into four layers, Layers 1 to 4 in descending order. A radiocarbon date of 7580±250 yrs. B.P. (GaK-10734) is obtained on collagen extracted from bone fragments from Layer 4. Fluorine content of nine bone fragments from Layers 2 to 4 ranges from 0.195% to 0.447% with an average of 0.299%, which is generally lower than that of fossil bones from limestone cave sediments of Pleistocene age in central and west Honshu. On the other hand, the fluorine content does not show any tendency to increase toward lower horizons. This suggests that Layers 2, 3 and 4 are roughly synchronous with each other. On the basis of these chronological data as well as the occurrence of the artifacts of Early Jomon type from Layer 2, it is concluded that Layers 2 to 4 are Early Holocene in age. The sediments of Tanuki-ana Cave can be regarded as a reference standard of the Early Holocene cave and fissure sediments on the Akiyoshi-dai Plateau, because the stratigraphic sequences of Quaternary cave and fissure sediments previously described in this area are mostly obscure and dated without sufficient grounds.