@article{oai:nagoya.repo.nii.ac.jp:00011751, author = {南, 雅代 and MINAMI, Masayo and 種, 紀彦 and TANE, Norihiko and 小田, 寛貴 and ODA, Hirotaka and 横田, 喜一郎 and YOKOTA, Kiichiro}, journal = {名古屋大学加速器質量分析計業績報告書}, month = {Mar}, note = {Lake sediment cores in Lake Biwa, KAN and KAS collected from the northern and southern basins, respectively, were measured for carbon content, δ^<13>C and Δ^<14>C. Acid-alkali-insoluble fraction (residue) and acid-soluble fraction obtained by acid-alkali-acid treatment of the sediments were analyzed. Carbon content of the northern basin sediment (KAN) is very high at the upper layer than 5cm depth and that of the southern basin sediment (KAS) has a highest peak at 19cm depth. δ^<13>C of KAN is the highest at 〜5cm depth layer and that of KAS is the highest at 〜20cm depth. The highest peak of KAS corresponded to 〜1960 A.D. might be effected by nourishing. Δ^<14>C suddenly increases between 1950 and 1985 in the vertical distribution of KAN residue. This high Δ^<14>C is due to contribution of artificial ^<14>C produced in atmosphere by nuclear and thermal nuclear tests after 1950A.D. Δ^<14>C of KAS residue has a wide peak between about 1920 and 1970. This suggests the sediment in the southern basin could be a little disturbed. The ^<14>C ages of KAN and KAS are older than the age obtained from ^<210>Pb or ^<137>Cs age, and the true sedimentation age cannot be decided from ^<14>C data of the sediments in this study. Therefore, the lake sediments need to be separated into much smaller fraction such as chlorophyll and lipid which are derived from lake phytoplankton. δ^<13>C and Δ^<14>C of residue are higher than those of acid-soluble fraction, indicating that ^<13>C and ^<14>C might be relatively gathered in fulvic acid. The sediments in rivers flowing in Lake Biwa were also measured for C content and δ^<13>C of residue and acid-soluble fractions. Carbon content of the residue in river sediments is especially low, while that of acid-soluble fraction is high. The δ^<13>C of river sediments is higher at the east-south side of Lake Biwa than at north-west side. This might be caused by different amount of plant and matter with high δ^<13>C at the east-south and north-west sides. Furthermore, the δ^<13>C of river sediments could affect the δ^<13>C of bottom sediments in Lake Biwa., 第17回名古屋大学タンデトロン加速器質量分析計シンポジウム平成16(2004)年度報告 Proceedings of the 17th symposiumon Researches Using the Tandetron AMS System at Nagoya University in 2004\ 日時:平成17 (2005)年1月24日(月)、25日(火) 会場:名古屋大学シンポジオン Date:January 24th and 25th, 2005 Place:Nagoya University Symposion Hall}, pages = {73--83}, title = {琵琶湖の湖底堆積物ならびに流入河川堆積物の炭素同位体比から探る堆積環境(第17回名古屋大学タンデトロン加速器質量分析計シンポジウム平成16(2004)年度報告)}, volume = {16}, year = {2005} }