179-129kaB．P．时段千年尺度气候事件的湖北神农架石笋记录  

Millennial-scale variability of East Asian summer monsoon during 179-129 ka B.P.from Shanbao Cave at Mountain Shennongjia,Hubei Province

作　　者：邵晓华[1] 汪永进[2] 程海 

机构地区：[1]南京信息工程大学遥感学院,江苏南京210044 [2]南京师范大学地理科学学院,江苏南京210097 [3]Department of Geology and Geophysics, Minnesota University MN 55455, USA

出　　处：《地球化学》2008年第2期107-117,共11页Geochimica

基　　金：国家杰出青年科学基金(40225007)

摘　　要：根据湖北神农架1支石笋(SB11)13个230Th年龄和638个δ18O数据,重建了179～129kaB.P.时段连续的高分辨率东亚夏季风历史。轨道尺度上石笋δ18O曲线呈现2个岁差旋回,指示东亚夏季风强弱变化受北半球夏季日辐射能量变化驱动。一系列千年尺度季风事件叠加于轨道尺度季风气候旋回上,与已有的东亚季风事件、北大西洋冰漂碎屑事件及地中海降温事件具有比较相似的变化规律,进一步证明了倒数第二次冰期千年尺度气候事件在北半球具有普遍性。山宝洞石笋记录与葫芦洞石笋记录的对比结果表明,最后两个冰期旋回千年尺度事件发生频率及变化幅度非常相似,有力地支持了千年尺度气候事件的冰量驱动模式。Millennial-scale climate oscillations during the Last Glacial have been documented in Greenland ice, marine, loess and cave sediments. Although paleoceanographic and loess studies provided evidence for millennial- scale climate variability scarce during the older during the penultimate glacial period, absolutely dated and high resolution records are period, hampering our understanding climate events and their global linkage. The previously reported of forcing mechanisms behind the millennial-scale Hulu records from Nanjing, East China, confirmed that rapid and short-lived events during the penultimate glacial period is essentially similar to those of the last glacial period, but not covered the whole glacial period. Here we present a continuous and high-resolution stalagmite oxygen isotope record between 179 - 129 ka B.P. from Shanbao Cave on the north slope of Mountain Shennongjia, Hubei Province, Central China. This record, established by 13 thorium-uranium ages and 638 oxygen-isotope data, ns of East Asian summer monsoon strength （about 70-year resolution） and their r times of contemporaneous deposition of stalagmites, Shanbao records replicate indicating that changes in monsoon strength are equally recorded well in the two represents high frequency variatio related precipitation changes. Fo remarkably well the Hulu records, localities with an 800 km distance apart. In general, the Shanbao record shows two processional cycles with amplitude of 3‰-4‰ in the δ^18O profile, indicating that Northern Hemisphere summer insolation plays an important role in driving the Asian monsoon on orbital scale. The first-order change in our record can be also correlated to the marine isotope stages （MIS） and sub-stages, named as from MLS6. 5 to 6.2. Millennial-scale oscillations in the δ^18O record are pronounced with amplitude from 1‰ to 2‰. These millennial oscillations are superimposed on the long-term orbital scale change. Six millennial-scale events of weakened summer monsoon documented in stalagmite δ^

关 键 词：倒数第二次冰期 千年尺度 东亚季风 石笋 山宝洞 神农架 

分 类 号：P597[天文地球—地球化学] P532[天文地球—地质学]