摘要
武都地区晚更新世以来堆积了厚约１７ｍ的黄土地层，其间夹有多层厚度不一、发育程度不同的古土壤层．在剖面１３．２～１７ｍ黄土中，野外可清晰的观察到６层古土壤．通过剖面磁化率、粒度、稳定同位素、元素地球化学、ＴＬ年代、ＣａＣＯ３、有机质含量的综合分析，认为它敏感而详尽地记录了深海氧同位素第５阶段的气候变化历史．对比研究结果显示：除总体模型与中国中西部黄土高原、深海氧同位素及南极冰心记录一致外，还可以与格陵兰Ｓｕｍｍｉｔ冰心记录进行良好的细节对比，揭示了全球气候变化地质记录的统一性．
The study results on Wudu loess section revealed that the thickness of loess accumulation during deep sea oxygen isotope stage 5 is 3.8m, which includes 6 layers of palaeosol and 5 interbeded loess layers. Based on the magnetic susceptibility measurement data and other analyses results, the isotope stage 5 recorded in Wudu loess can be divided into 5a,5b,5c,5d and 5e, in which 5c can further be divided into 5c5,5c2 and 5c3; 5e can be divided into 5e1,5e2,5e3,5e4 and 5e5.The climate history reflected by Wudu Loess section shows that the period of 5e5 was the warmest and most humid time during last 150 ka BP. During 5e3,5c2,5c1 and 5a the climate was nearly the same as that of the present. On the other hand, it can also be induced that during 5e4,5e2,5d,5b and 5c2 the climate was cold and there possibly were glacier advances on the high mountains and polar areas.The choronology of Wudu loess section has been determined based on the 14c and TL datings and in the reference of insolation amount at 45° North latitude. It is generally in agreement with the time scale of the deep sea oxygen isotope.The detailed correlation between the climate records of Wudu loess, deep sea oxygen isotope curves, polar ice cores and solar insolations implies that the global climate changes at the same time, which further supports the controlling function of Milankvich theory on global climatic change
出处
《兰州大学学报（自然科学版）》
CAS
CSCD
北大核心
1997年第4期107-115,共9页
Journal of Lanzhou University(Natural Sciences)
基金
国家自然科学基金
