神农架三宝洞倒数第二次冰期高分辨率石笋δ^(13)C记录  

A HIGH-RESOLUTION STALAGMITE δ^(13)C RECORD FROM SANBAO CAVE OVER THE PENULTIMATE GLACIATION

作　　者：姜修洋[1,2] 孔兴功[2] 汪永进[2] 程海[2,3] 张春霞[2] 

机构地区：[1]福建师范大学地理科学学院,福州350007 [2]南京师范大学地理科学学院,南京210046 [3]Department of Geology and Geophysics, University of Minnesota

出　　处：《第四纪研究》2011年第1期1-7,共7页Quaternary Sciences

基　　金：国家自然科学基金重点项目(批准号:40631003);国家自然科学基金项目(批准号:40771009);江苏省研究生创新计划项目(批准号:CX07B-051Z)资助

摘　　要：基于神农架三宝洞两支石笋24个^(230)Th年龄以及637个δ^(13)C测试数据,建立了倒数第二次冰期191±1.8～133±0.6ka B.P.时段洞穴石笋高分辨率δ^(13)C的时间序列。在冰期/间冰期尺度上,δ^(13)C值振幅达4.5‰,整体变化趋势与全球冰量曲线类似。在倒数第二次冰期,石笋δ^(13)C记录揭示出一系列较大振荡幅度的千年尺度气候事件,并且与北大西洋SST记录的倒数第二次冰期9个千年尺度冷暖事件一一对应,甚至在某些DO亚旋回事件上也具有一定的对应关系。倒数第二次冰期北大西洋6个冰漂碎屑事件也在三宝洞石笋δ^(13)C记录中留有印迹。三宝洞石笋δ^(13)C记录将末次冰期东亚季风气候与北大西洋气候的联系拓展至倒数第二次冰期,进一步说明倒数第二次冰期北大西洋温盐环流对季风气候仍然起着中重要的作用。The study of millennial-scale abrupt climate change has focused mainly on the last glacial period and provided important insights about the dynamics of the climate system. Some of these records also suggest that high-frequency climate variability was not restricted to this period. Previously studies on the Shennongjia Caves demonstrated a strong correlation with Greenland climate during the last glacial. However, it was not clear whether the millennialscale temperature changes in the North Atlantic exert significant influence on the ASM during the penultimate glacial. An understanding of MIS 6 climate may help to unravel the underlying dynamics that control glacial climate variability. Sanbao Cave （31° 40＇ N, 110° 26＇E）is located at an elevation of 1902m on the northern slope of Mt. Shennongjia, near the southern edge of the Chinese Loess Plateau. The cave site is strongly influenced by East Asian summer monsoon （EASM） which brings the greatest amount of moisture to the region. The mean annual precipitation at the site ranges between 1500mm and 2000mm, 60% - 80% of which falls between Jun. and Sep. Relative humidity in the cave is 95% - 100% and cave temperatures （9℃） approximate a mean annual temperature of outside atmosphere. Two stalagmites（ SB24 and SB42）recovered from Sanbao Cave in Shennongjia, China, established with 24 ^230Th ages and 637 δ^13C data, provides a continuous, high-resolution, precisely dated palaeoclimate record covering the coldest part of the penultimate glacial（ 191±1.8 - 133±0.6kaB. P. ）. 637 sub-samples for δ^13C measurements were run at the Isotope Laboratory of Nanjing Normal University with on-line automated carbonate preparation system （Kiel Carbonate Device）linked to Finnigan MAT-253, yielding a standard deviation error of 0.05‰. Twenty-four 230Th dates were conducted at the Isotope Laboratory of Geology and Geophysics Department, University of Minnesota, USA. The reported error is in±2σ. Stable carbon isotope ratios from Sanbao Cave show

关 键 词：三宝洞 δ^13C倒数第二次冰期DO事件 

分 类 号：P532[天文地球—古生物学与地层学] P931.4[天文地球—地质学]