黔南七星洞石笋古气候变化记录及末次间冰期终止点的确定  

The Record of Paleoclimatic Change and the Termination of the Last Interglacial Period From A Stalagmite of Qingxin Cave in South Guizhou

作　　者：张美良[1] 林玉石[1] 覃嘉铭[1] 章程[1] 涂林玲[1] 程海[2] 

机构地区：[1]中国地质科学院岩溶地质研究所岩溶动力学开放研究实验室,广西桂林541004 [2]美国明尼苏达大学地质与地球物理系,美国mn55455

出　　处：《沉积学报》2003年第3期473-481,共9页Acta Sedimentologica Sinica

基　　金：IGCP 448国际对比项目;科技部攀登特别资助项目"全球岩溶生态系统对比"(编号 :2 0 0 0 - 0 2 6)资助

摘　　要：当前在全球气候变化预测研究中 ,洞穴石笋的高分辨定年和碳、氧同位素组成的变化规律研究 ,为这个领域的突破和填补空白做出了巨大贡献。通过对贵州都匀七星洞 1号石笋进行 11件TIMS U系测年和 79件碳、氧同位素分析 ,获得了距今 10 9.0 0kaB .P .至 6 5 .90kaB .P .的高分辨率古气候记录。石笋在大于 10 9.0 0kaB .P .前开始生长 ,于 6 5 .90kaB .P .后停止生长 ,平均沉积速率为 4 .5 8mm/ 10 0a,属晚更新世的沉积产物。七星洞 1号石笋剖面的研究揭示 ,其年龄和δ18O同位素的变化 ,可以与深海岩芯氧同位素记录所揭示的第五阶段中的 5a、5b、5c和第四阶段的早期进行对比。它的碳、氧同位素记录揭示 ,在 10 9.0～ 10 2 .5kaB .P .和 86 .6～ 78.92kaB .P .时段 ,显示受东亚夏季风影响较强 ,气温升高 ,降水增多 ,δ18O偏负 ,表现为温暖湿润的气候环境。在 10 2 .5～ 86 .6kaB .P .时段 ,显示受东亚夏季风影响强度减弱 ,受东亚冬季风影响强度增加 ,气温降低 ,大气降水减少 ,δ18O稍趋向偏正 ,表现为冷凉半湿润—温凉湿润的气候环境 ;而在 78.92～ 6 5 .6kaB .P .时段 ,显示东亚冬季风强盛和受西北风影响较强 ,海表温度下降 ,大气温度降低 ,降水量较少 ,δ18O偏重 ,δ13 C偏正 (C4植物占 95 % ) 。Under the predictive study of the global climate change at present, the dating ages of the high-resolution and the change law revealed by the carbon and oxy ge n isotopic composition from cave stalagmites have made a great contribution for the breakthrough and filling gaps in this field. The high-resolution cl im ate records from 109.00 ka B.P. to 65.90 ka B.P. have been obtained through TIMS -U series dating of 11 samples and carbon and oxygen isotopic analysis of 79 sampl es from No.1 stalagmites in the south part of Guizhou. The No.1 stalagmite began to grow before 109.00 ka B.P. and stopped to grow after 65.90 ka B.P.,its ave rag e growth rate is 4.58mm/100a and is the sediment of the late Pleistocene. The st udy of No.1 stalagmite section in the Qingxin cave reveals that its age and isot ope records can be compared with the oxygen isotopic records of deep-sea cores or sediments at 5a, 5b and 5c phase of Ⅴstage and Ⅳ stage and Lishi Loess beds(L2) in the north of China. The carbon and oxygen isotopic records of stalagmite reveal that these tw o stages between 109.0～102.5 ka B.P. and 86.6～82.0 ka B.P. represented the war m-humid climatic environment and indicated the strong influence of the Asian (Southeast) summer monsoon, the rainfall increased more,the δ 18 O trende d to lowre or negative and the air temperature rose.The stage from 102.5 ka B.P. to 86.6 ka B.P. represented the cold-cool semi-arid and warm-cool humid cli matic envi ronment and indicated that the Asian (Southeast) summer monsoon was gradually weak, the meteoric water was decreased gradually, the δ 18 O was much h e avier, and the air temperature gradually decreased. And the stage from 78.92 ka B.P. t o 65.90 ka B.P. represented the dry-cold climatic environment and indicated tha t t he Asian (Southeast) winter monsoon and the Northwest cold air mass were streng thened, the meteoric water was decreased gradually, the δ 18 O was much hea vier, a nd the air temperature went down quickly,and is the col

关 键 词：全球气候变化预测 石笋 铀系年龄 古气候 末次间冰期 七星洞 

分 类 号：P642.25[天文地球—工程地质学] P532[天文地球—地质矿产勘探]