干旱区生态环境知识资源中心(Arid): 巴丹吉林沙漠东南缘末次冰期沉积物地球化学特征及气候指示意义

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	巴丹吉林沙漠东南缘末次冰期沉积物地球化学特征及气候指示意义
其他题名	Geochemical characteristics and paleoclimatic significance of the last glacial sediments in the southeastern margin of Badain Jaran Desert
	范小露; 张新毅; 田明中
来源期刊	干旱区地理
ISSN	1000-6060
出版年	2021
卷号	44 期号:2 页码:1000-6060
中文摘要	沙漠古气候重建对于了解区域古气候演变具有重要意义。通过以巴丹吉林沙漠东南缘巴润宝日陶勒盖(BRBG)剖面为研究对象,进行全样地球化学、分组分分粒级元素地球化学及Sr同位素分析,重建该地区末次冰期期间(66.8~41.0 ka)的气候演化模式。研究表明:66.8~41.0 ka呈现残留组分高Sr/Ca值、酸溶组分及残留组分低Ba含量特征,指示化学风化增强及湖泊补给量增加,反映暖湿气候特征。微量元素变化特征指示沉积物细粒组分中的微量元素指标对气候的敏感度高于粗粒组分。Sr同位素结果显示酸溶组分中~(87)Sr/~(86)Sr值在66.8 ka附近达到最大值,可能与湖水盐度升高相关。此外,几乎所有指标均指示在41.0 ka前后存在一次气候突变事件,研究认为巴丹吉林沙漠东南缘41.0 ka前后从暖湿突变为干冷气候可能是该时期的西伯利亚高压系统增强所致。
英文摘要	Reconstructing the desert paleoclimate is critical for understanding paleoclimate evolution. As the third-largest desert in China, the Badain Jaran Deserts mega dune is the highest in China and the world and unique for its crowded mega dunes. This regions geology and environmental information are challenging to acquire. By using innovative methods and techniques to study the Badain Jaran Deserts climate change, research will significantly influence climate studies in the northwest arid area and even East Asia. The climate evolution model during the last glacial period (66.8-41.0 ka) in the Barunbaoritaolegai (BRBG) section in the southeastern margin of the Badain Jaran Desert was reconstructed using whole-sample geochemistry, granular-scale element geochemistry, and Sr isotope analysis. During 66.8-41.0 ka, the residual components showed high Sr/Ca values, whereas acid-soluble and residual components showed low Ba contents, indicating enhanced chemical weathering and increased lake supply, reflecting the characteristics of a warm and humid climate. The trace element changes indicate that trace elements in the fine grain components of sediments are more sensitive to climate than the coarse ones. Although the geochemical indices from the entire sample show little obvious feedback, the other innovative technique used in this study suggests higher efficiency and more sensitivity to environmental variation. Therefore, this approach could be used in future studies on climate and environmental variation. Based on the experimental outputs, the K and Sr concentrations in the residual components of fine fraction (<125 mum), the Sr/Ca values of residual components of fine fraction (<125 mum), the K concentrations in the acid-soluble components of the coarse fraction (>125 mum), and the Al concentrations in both acid-soluble and residual components of the coarse fraction (>125 mum) are the typical sensitive chemical indicators of climate change. The research group found that fine-sized fractions in the sediments are sensitive to climate change, which is an ideal media to reflect environmental vibration. By introducing novel ideas to climate-related research, the team discovered that Ba variations in acid-soluble fractions are highly sensitive, whether in fine or coarse grain-sized sediments. The ~(87)Sr/~(86)Sr ratio of sediments from the inland lake is a critical indicator of chemical weathering intensity. The ratio change in acid-dissolved components indicates a change in strontium in the deposition area, whereas the ratio change in residual components reflects a change in strontium in the source area. The opposite trend is evident for the strontium ratio, showing that the response of different sediment components to chemical weathering is different in the provenance and sedimentary regions. Sr isotope results show that the ~(87)Sr/~(86)Sr value reached a maximum at ~66.8 ka, which could be related to the increase in lake water salinity. Furthermore, most indicators show a sudden climate change at ~41.0 ka, and the study indicates that the abrupt change from warm wet climate to dry cold climate at ~41.0 ka in the southeastern margin of Badain Jaran Desert might be caused by the enhancement of a Siberian high-pressure system in this period.
中文关键词	末次冰期 ; 地球化学 ; 古气候 ; 西伯利亚高压 ; 巴丹吉林沙漠
英文关键词	last glacial period geochemical paleoclimate Siberian high pressure system Badain Jaran Desert
类型	Article
语种	中文
国家	中国
收录类别	CSCD
WOS类目	Geology
CSCD记录号	CSCD:6950255
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/354256
作者单位	范小露, 阜阳师范大学历史文化与旅游学院地理系;;阜阳师范大学皖北文化研究中心, ;;, 阜阳;;阜阳, 安徽;;安徽 236037;;236037, 中国.; 张新毅, 阜阳师范大学历史文化与旅游学院地理系;;阜阳师范大学皖北文化研究中心, ;;, 阜阳;;阜阳, 安徽;;安徽 236037;;236037, 中国.; 田明中, 中国地质大学(北京)地球科学与资源学院, 北京 100083, 中国.
推荐引用方式 GB/T 7714	范小露,张新毅,田明中. 巴丹吉林沙漠东南缘末次冰期沉积物地球化学特征及气候指示意义[J],2021,44(2):1000-6060.
APA	范小露,张新毅,&田明中.(2021).巴丹吉林沙漠东南缘末次冰期沉积物地球化学特征及气候指示意义.干旱区地理,44(2),1000-6060.
MLA	范小露,et al."巴丹吉林沙漠东南缘末次冰期沉积物地球化学特征及气候指示意义".干旱区地理 44.2(2021):1000-6060.