@article{oai:nagoya.repo.nii.ac.jp:00011783,
 author = {加藤, 茂弘 and KATOH, Shigehiro and 半田, 久美子 and HANDA, Kumiko and 兵頭, 政幸 and HYODO, Masayuki and 佐藤, 裕司 and SATO, Hiroshi and 中村, 俊夫 and NAKAMURA, Toshio and 山下, 透 and YAMASHITA, Tohru and 檀原, 徹 and DANHARA, Tohru},
 journal = {名古屋大学加速器質量分析計業績報告書},
 month = {Mar},
 note = {The Ohnuma Moor in the eastern part of the Chugoku Mountains, western Japan, is located about 80-km west of Daisen Volcano and more than 100-km west of Sambe Volcano. The moor has thick sediments more than 65 meters which are composed of finer peat and organic clay and silt above about 17 meters in depths, and of coarser sand and gravels below. The finer part contains four tephra layers that were correlated with Kikai-Akahoya Volcanic Ash Bed (K-Ah), Daisen-Misen Pumice Bed (MsP), Daisen Shitano-hoki Volcanic Ash Bed (Sh), and Aira-Tanzawa Volcanic Ash Bed (AT) in descending stratigraphic order. We have newly found two volcanic ash layers between the K-Ah and MsP, and below the AT in the finer sediments. Based on the petrologic characteristics of these two tephra layers, the upper tephra layer is correlated with the Sambe Ukinuno Volcanic Ash Bed (SUk), and the lower is correlative to the Daisen Nise-hoki Volcanic Ash Bed (Nh). The eruptive ages of five tephra layers except for the K-Ah are estimated on the basis of 22 AMS-^<14>C dates obtained for the moor deposits above 17 meters in depths, with the assumption of a constant sedimentation rate between horizons where the AMS-^<14>C dates are measured. As the results, the estimated eruption ages of the SUk, MsP, Sh, AT, and Nh are 16,740±150 ^<14>CyBP, 24,000±150 ^<14>CyBP, 24,320±150 ^<14>CyBP, 24,830±100 ^<14>CyBP, and 35,660±200 ^<14>CyBP, respectively. The estimated ages are in good agreement with the results of the previous studies, although the MsP is considered to have erupted at the age by 5,500 to 7,500 years older than the previous estimated age of 16,500 to 18,500 ^<14>CyBP. This may be resulted from mismatching of tephra correlation and/or pollution of materials used for the ^<14>C-age determination in the previous studies., 第18回名古屋大学年代測定総合研究センターシンポジウム平成17(2005)年度報告 Proceedings of the 18th symposiumon on Chronological Studies at the Nagoya University Center for Chronological Research\
in 2005 日時:平成18 (2006)年1月17日(火)､18日(水) 会場:名古屋大学シンポジオン Date:Januaryl7th and 18th, 2006 Venue:Nagoya Uhiversity Symposion Hall},
 pages = {77--91},
 title = {中国山地東部の大沼湿原堆積物に挟まれるテフラの対比と推定噴出年代(第18回名古屋大学年代測定総合研究センターシンポジウム平成17(2005)年度報告)},
 volume = {17},
 year = {2006}
}