摘要
通过对腾格里沙漠东南部昂格尔图湖岩芯AGE15A的粒度、碳酸盐的百分含量和主要化学元素等多项沉积学气候代用指标及精确定年的综合分析,重建了该区域988 AD以来的古气候变化序列。结果表明:988 AD以来的研究区的气候环境的演化过程与我国西北西风区古气候变化基本一致,呈现"冷湿—暖干"交替变化的特征,但在时间上存在一定的延迟。具体表现为:988～1383 AD,昂格尔图湖由洼地发育成小型湖泊,化学风化作用弱,湖区气候环境整体偏冷湿,期间出现几次暖波动; 1383～1560 AD,研究区处在中世纪暖期,为温暖、干旱的气候特征,此时湖泊扩张,湖中水生植物生长茂盛,呼吸作用增强,造成大量的碳酸盐沉淀,最高值达到8. 16%; 1560～1700AD,致使气候在昂格尔图湖形成之后出现最寒冷的时期,降水增加,气候湿冷,此时段与小冰期最盛期相对应; 1700 AD之后,温度开始上升,气候回暖,在1900 AD左右达到最甚,此时沉积物中碳酸盐的百分含量也达到最大值,为10. 15%,此期间湖泊继续扩张,出现几次气候冷波动。基于我国古代文献重建的历史时期气候变化基本不包括沙漠地区,所以本文利用湖相沉积记录来反演腾格里沙漠昂格尔图湖历史时期的气候环境演变,对中国沙漠研究有着重要参考价值,同时也为中国西北历史时期的气候重建提供科学依据。
Reconstruction of Chinese paleoclimatic changes based on ancient written records basically seldom covered the desert regions.The study on ancient climate change based on records from lakes in deserts is a weak point and needs to be strengthened.Research on physicochemical properties of lacustrine sediment,such as the particle size,the chemical elements and the percentage composition of carbonate,is one of the most important methods of inverting the history of local climate change.In this paper,the paleoclimatic/environmental changes of Tengger Desert,Inner Mongolia,China,since 988AD are investigated by acquiring a 166cm long sediment core from the Anggeertu Lake in the desert.The physicochemical analyses mainly focus on the characteristics of grain size,X-ray was weak.The climate was overall cold and wet accompanied by several warm fluctuations.The period of 1383- 1560AD was in the Medieval Warm Period when the climate Was warm and dry in the study area.The Anggeertu Lake was expanded with rapid growth of aquatic plants resulting in precipitation of massive carbonate,which accounted for 8.16%of the lake sediment.With the arrival of Little Ice Age Maximum in China (1560-1700AD), the coldest period came after the formation of the Anggeertu Lake.The precipitation was increased and the climate went colder and wetter.After 1700AD,the particle size of lake sediment was getting finer year by year .and Anggeertu Lake continued to expand.The temperature began to rise,reaching its peak in 1900AD along with several Wet fluctuation during this period (1700-1900AD).In addition,the percentage of carbonate reached 10.15%.Af- ter the formation of the Anggeertu Lake,the climate in the study area is characterized by alternating "cold-wet"and "warm-dry".This kind of climatic evolution property of lacustrine sediment was consistent with what other indicators revealed in northwest westerly region of China.However,there exists a temporal hysteresis by using physicochemical analyses.These preliminary results can provide important references to study the paleoclimatic changes of deserts in northwest China.At the same time,this paper has improved the unbalanced research work on arid and semi-arid area in China.
作者
曹志宏
安成邦
尹丽颖
段阜涛
郝盛吞
周爱锋
CAO Zhi-hong;AN Cheng-bang;YIN Li-ying;DUAN Fu-tao;HAO Sheng-tun;ZHOU Ai-feng(Key Laboratory of Western China's Environmental Systems,Lanzhou University,Lanzhou 730000,Gansu,China)
出处
《干旱区地理》
CSCD
北大核心
2018年第6期1251-1259,共9页
Arid Land Geography
基金
国家科技基础资源调查专项(2017FY101003)
国家自然科学基金项目(41372180)资助
关键词
湖相沉积
粒度特征
XRF岩芯扫描分析
气候变化
腾格里沙漠
lake sediment
characteristic of grain size
X-ray Fluorescence (XRF)core scanner analysis
climate change
Tengger Desert
