摘要
武都黄土剖面的研究结果表明：它完整且高分辨率地记录了晚更新以来气候环境变化的历史，清晰易辨的黄土——古土壤系列和稳定的磁化率特征反映了这种变化的全过程；系统的元素地球化学分析证明武都黄土物质构成主体部分与黄土高原一致；大旋回、大幅度的粒度变化特点说明它受控于远距离、大尺度搬运过程及风力强弱的交替．剖面ＣａＣＯ３、有机质含量、ＣａＣＯ３及有机质稳定同位素综合反映了不同时期气候环境状况、植被及生物量大小．基于剖面１４Ｃ、ＴＬ测年及与深海氧同位素阶段和北纬４５°冬夏辐射曲线的仔细对比，建立了武都剖面的年代序列．对比分析结果表明，武都剖面磁化率曲线与深海氧同位素曲线、格陵兰Ｓｕｍｍｉｔ及南极Ｖｏｓｔｏｋδ１８Ｏ曲线具良好的对比性，且与北纬４５°年辐射量成正相关。
The results of the studies on Wudu Loess section show that it has completely recorded the history of climatic environment of change since late Pleistocene with a high resolution and clearly displayed Loess palaeosol sequences and the related palaeomagnetic susceptibility. The results of systematic elemental geochemical analyses support the idea that the main material of Wudu Loess is similar to that of Loess Plateau. The Megacircularity and big magnitude properties of the grain size, indicate that the transportation of loess material was controlled by the long range changeable wind systems. The contents of CaCO 3 and organic materials revealed the climatic environmental conditions of different periods.Based on the 14 C and TL dating, by studying the correlation the deep sea oxygen isotope stages and the summer winter radiation at 45 degree latitude, the chronology of the Wudu Loess section has been established. The results show that there exist good relations between the curve of palaeomagnetic susceptibility of Wudu Loess and that of deep sea oxygen isotope, between the former curve and the oxygen isotope curves of the Summit ice core of Greenland and Vostok ice core of Antarctic. It is related with the annual isolation amount at 45 degree latitude this supporting the view that global climate is controlled by isolations.
出处
《兰州大学学报（自然科学版）》
CAS
CSCD
北大核心
1997年第1期105-114,共10页
Journal of Lanzhou University(Natural Sciences)
基金
国家自然科学基金
