%0 Journal Article %T 13kaBP以来滇池地区古环境演化 %T Paleoenvironmental Evolutionin Dianehi Lake Area since 13kaBP %A 吴艳宏 %A 吴瑞金 %A 薛滨 %A 钱君龙 %A 肖家仪 %A Wu Yanhong %A Wu Ruijin %A Xue Bin %A Qian Junlong %A Xiao Jiayi %J 湖泊科学 %J Journal of Lake Sciences %@ 1003-5427 %V 10 %N 2 %D 1998 %P 5-9 %K 滇池;古环境;13ka %K Dianehl Lake;paleoenvironment;13kaBP %X 根据DC93一1孔孢粉组合、总有机碳(TOC)、总氮(TN)、碳氮比(C/N)、有机碳同位素δ13Corg、磁化率(χ)、频率磁化率(χfd)等资料,结合14C、210Pb和137Cs测年,滇池地区13ka以来的古环境演化历史经历了以下几个阶段:13—10.2kaBP.气候偏凉湿,湖水深度不大;10.2-7.5kaBP,气候向暖湿过渡.湖水渐深;7.5-4.0kaBP,气候暖湿,出热条件达到最佳配制,湖水也最深.6.5kaBP前后,气温最高,这一时段古气候状况存在次级波动;4.0-2.7kaBP,气候突转干旱.湖水最浅;2.7-1.7kaBP,气候温湿,湖面扩大,湖水变深;1.7kaBP,人类活动影响的加剧,使湖泊环境的变化更为复杂. %X Dianchi Lake (25°04 N,102°41’E ),lying to the south of Kunm ing City·the capital ofYunnan Province,is an ideaI field for studying the evolution of the Southwest M onsoon.The core D93-l is sampled in the Iake at the depth of 4.05m.The 14C ages at 0.65m. 1.7m,2,65m and 3.95m are 1 670± 1 40aBP,4540± 220aBP,6700± 160aBP and 2900± 1100aBP respectively. The sediment rate of upper layer determ ined by 210Pb and 127Cs measurement was about 1.78mm/a after 1948A,D.,and lmm/a for the Iast 250 years,Meanwhile.such environmentaI proxies as pollen assemblage.totaI organic carbon(TOC). Total nitrogen(TN)+(C/N),13Corg,magnetic susceptibility (X)and frequency dependent m agnetic susceptibility (X fd)·have been used to restore the history of environm ental evolution in the lake area since 13kaBP.As a result,Dianchi Lake has undergone the following clim atic variations since 13kaBP; 13-10kaBP.it was cool and wet;l0-7.5kaBP.it was a transitionaI period while clim atetransited to warm and wet and Iake water leveI becam e higher. 7.5-4kaBP.it was warmand wet with little variation. The highest temperature em erged about 6.5kaBP,4-2,7kaBP,the clim ate changed to cool and dry,suggesting an abrupt change in environm entalproxies,2,7-1.7kaBP+ all environmental proxies exhibited the characteristics of slightwarm and wet climate, and, lake area enlarged with lake water level uprising, Since1.7kaBP human activity has m ade a notable impact on the environm entaI evolution. %R 10.18307/1998.0202 %U http://www.jlakes.org/ch/reader/view_abstract.aspx %1 JIS Version 3.0.0