@article{oai:nagoya.repo.nii.ac.jp:00011782, author = {西村, 弥亜 and Nishimura, Mitsugu and 松中, 哲也 and Matsunaka, Tetsuya and 中村, 俊夫 and Nakamura, Toshio and 渡邊, 隆広 and Watanabe, Takahiro and 寺井, 久慈 and Terai, Hisashige and 中野, 志穂 and Nakano, Shiho and ツウ, リッピン and Zhu, Liping}, journal = {名古屋大学加速器質量分析計業績報告書}, month = {Mar}, note = {Little has been known about the details as to how the Tibetan Plateau had responded to global climatic oscillations in the paleoenvironmental history. Using a sediment core (ca. 4m in length) from Lake Pumayum Co located in the southeastern part of the plateau, we have been attempting to elucidate when the deglaciation and the warm and wet conditions since the last glacial maximum (LGM) took place around the region. For the purpose, we investigated the historical change of organic sources to the lake sediments with alkanes, an useful biomarker which can provide information on biological sources of sedimentary organic matter. The following results have been obtained so far : 1) The alkane source parameters (CPI&ACL) indicated that around 350cm in depth of the core, the relative contribution of organic matter from aquatic plants to sediments rapidly and strikingly decreased, while that of soil organic matter increased. 2) The ^<14>C ages obtained sometimes reversed between 240cm and 340cm, and further went back to younger ages between 340cm and 390cm. Based on the basis of a good correlation between the vertical profiles of ACL and the ages, it was suggested that the variable ages might be due to the changes of major sedimentary organic sources from aquatic plants to soil. 3) Although among the four ^<14>C ages obtained between 310cm and 340cm, one age reversed, all data showed the ages of almost 19,000 cal yr B.P. From this, it was implied that the rapid and striking change of the organic sources found around 350cm in core depth was caused by deglaciation., 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 = {68--76}, title = {チベット高原南東部における、最終氷期最寒冷期後の気候・環境変化に関する有機地球化学的研究(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} }