贵州荔波董歌洞D3石笋碳氧稳定同位素及微量元素记录的环境变化  

The Stable Isotope and Trace Element Records on Environmental Change of D3 Stalagmite in Dongge Cave, Libo, Guizhou

作　　者：覃嘉铭[1] 袁道先[1] 程海 林玉石[1] 张美良[1] 

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 [2]Geology and Geophysics Department, Minnesota University, MN55455, USA

出　　处：《地球学报》2004年第6期625-632,共8页Acta Geoscientica Sinica

基　　金：国家自然科学基金项目 (批准号 :4963 2 10 0 )及(4 0 15 2 0 0 2 );国土资源部重点科技项目 (批准号 :95 0 110 4)资助

摘　　要：通过对贵州荔波董歌洞D3石笋一系列的TIMSU系法测年以及碳氧稳定同位素分析 ,取得了连续 90 .0～ 16 0 .0ka气候变化高分辨率的同位素记录。表明石笋氧同位素记录和海洋同位素记录一样 ,也可以明显地按峰、谷划分为MIS5c,MIS5d ,MIS5e及MIS6多个气候阶段 ,界线年龄分别为 :5c/ 5d为 110 .0kaBP ,5d/ 5e为 12 0 .0kaBP ,5e/ 6为 12 9.2kaBP。在由冰盛期的 6阶段到间冰期的 5e,δ18O值由偏重的谷底至偏轻的峰顶的跃变 ,代表冰期旋回之间由冷到暖的快速转变。此外 ,δ13 C值也同样自谷底至峰顶的快速变化 ,说明生态环境也随气候环境的迅速变化而变化。系统的微量元素分析表明 ,Si,Al,Sr,P ,F等均表现出由冰盛期 6阶段至间冰期 5e阶段最大幅度的迅速变化 ,在间冰期 ,微量元素记录变化幅度较小 ,变化波形与δ13 C记录更为相似 ,研究表明 ,这些微量元素与δ13 C记录一样也可以作为岩溶区生态环境重建的代用指标。Through a lot of TIMS-U series dating and the carbon oxygen stable isotope analysis of D 3 stalagmite form Dongge Cave, Libo, Guizhou, the authors obtained high resolution isotope record of climatic changes from 90 000 to 160 000 a successively. The study indicates that the stalagmitic oxygen isotope records are identical with the sea isotope record.Accoding to the peaks and the valley, they can be divides into MIS5c, MIS5d, MIS5e and MIS6 climates stage, with the boundaries being 5c/5d 110 ka B P, 5d/5e 120 ka B P, 5e/6 129.2 ka B P respectively. From 6 flourishing stages to the Interglacial 5e, the δ 18O value jumped from the heavy valley to the light peak, representing therapid change of the glacial cycle from cold to warm. The δ 13C values also show similar rapid changes from the valley to the peak, suggesting the rapid change of the ecological environment with the climatic change. Systematic trace element analysis indicates that Si, Al, Sr, P, F and some other elements all show very remarkable changes from the 6 glacial flourishing stages to the Interglacial 5e stage. In the Interglacial epoch, the trace element change are smaller, and the change curve is more similar to the δ 13C record. Researches show that, like the δ 13C records, these trace elements can also serve as indicators for the reconstruction of the karst area ecological environment.

关 键 词：石笋 间冰期 稳定同位素 Δ^13C 代用指标 Δ^18O 冰期旋回 MIS BP 记录 

分 类 号：P532[天文地球—古生物学与地层学] P467[天文地球—地质学]