摘要
通过对贵州都匀七星洞4根石笋系统的31件TIMSU系及543件稳定同位素分析,揭示出其气候变化记录时限范围为1.1～8.5万a,相当于海洋同位素阶段的MIS2,MIS3,MIS4及MIS5a。根据δ18O的变化可以准确确定它们之间的界线,其年龄值为:MIS1/MIS211.3kaB.P.,MIS2/MIS328.7kaB.P.,MIS3/MIS459.6kaB.P.,MIS4/MIS5a78.5kaB.P.。研究表明,末次冰期相当于格陵兰冰芯记录、北大西洋沉积记录的YD、Heinrich事件等的气候跃变事件,几根石笋取得了非常一致的准确定位及定年。其中YD事件发生于12.76～11.52kaB.P.,Heinrich事件的H1～H6分别为15～17kaB.P.,24.6kaB.P.,30.5kaB.P.,39.3kaB.P.,46.8～47.8kaB.P.以及60.4kaB.P.。在MIS4阶段,石笋记录于66.4kaB.P.及73.8kaB.P.揭示了两次冷事件,也可于格陵兰冰芯记录中找到相对应的冷谷。通过与GISP2的对比研究,表明东亚季风气候的百年至千年尺度的气候演变,与北大西洋及格陵兰高纬度地区的气候变化具有非常协调的对应关系。它对研究季风气候的动力机制及其与全球变化的响应关系具有特别重要的意义。
Through 31 TIMS- U series dating and 543 samples of carbon oxygen stable isotope analysis from 4 stalagmites in Qixing cave, 11000 to 85000a climatic changes isotope records are obtained continuously. The study indicates that stalagmite's oxygen isotope records are same with the sea isotope records, which also may be divided correspondingly to MIS2, MIS3, MIS4 and MIS5a climates stages. And the demarcation lines are as follows: 11.3ka B.P. between MIS1 and MIS2, 28.7 ka B.P. between MIS2 and MIS3, 59.6 ka B.P. between MIS3 and MIS4, and 78.5 ka B.P. between MIS4 and MIS5a. It is showed by the study on stalagmite records that the last glacial epoch corresponds to YD and the Heinrich events recorded in North Atlantic sediment, and also corresponds to ice core from Greenland. Several pieces of stalagmite are of extremely consistent and exact locating and timing. The age of the YD event occured 12.76～11.52 kaB.P., and H1～H6 of the Heinrich event is respectively 15～17 kaB.P., 24.6kaB.P., 30.5kaB.P., 39.3kaB.P., 46.8～47.8kaB.P., 60.4kaB.P.. The stalagmite records expose out two cold events at 66.4kaB.P. and 73.8 kaB.P. during MIS4, those are very similar to the two clough in Greenland ice core record curve. A comparing study with GISP2 indicated that the climate transition of East Asian monsoon in hundred and thousand years scale is consistent to the North Atlantic and Greenland climate change. It is significant for the study on the dynamical mechanism of East Asia monsoon climate and on the corresponding relationship to global change.
出处
《中国岩溶》
CAS
CSCD
2003年第3期167-173,共7页
Carsologica Sinica
基金
国家自然科学基金(批准号:49632100)
(批准号:40152002)资助项目
国土资源部重点科技项目(批准号:9501104)
