中文摘要：

下蜀黄土记录了东亚季风环境演变的重要信息,是全球气候变化研究的重要载体。通过对南京仙林（XL）剖面下蜀黄土地球化学元素、风化指标和磁化率指标的综合分析,讨论了南京下蜀黄土的化学风化程度及沉积环境。研究结果表明,南京下蜀黄土的常量元素与上陆壳化学组分接近,显示其物质来源比较稳定,在堆积以前经历了充分的混合。XL地区的沉积环境比洛川黄土沉积环境要湿润,与洛川古土壤、镇江下蜀黄土的沉积环境接近,处于较为湿润条件下形成的中等风化阶段。在250~100ka期间,XL剖面的沉积环境经历了冷干-暖湿-冷湿-暖湿的变化特征。同时,长江中下游地区在此期间具有风化成壤作用逐渐增强、气候逐渐暖湿、东亚夏季风逐渐增强的特点。

英文摘要：

The environmental records from Xiashu loess are of great importance to understand the evolution of the East Asian monsoon.It’s the important carrier of the global climate change research.The material is selected from a typical profile of Xiashu loess at Xianlin,Nanjing.We analyzed the chemical elements,weathering parameters and magnetic susceptibility.The climate proxies reflect the chemical weathering degree and the sedimentary environment.The chemical elements results show that the major element contents of Nanjing Xiashu loess are comparable to the average composition of the upper continental crust.It indicates the material sources of XL Xiashu loess were stable and it was derived from well-mixed sedimentary protoliths which had undergone numerous upper crustal recycling processes.The results of CIA show that the pedogenic environment of XL area is wetter than Luochuan loess and similar to Luochuan paleosoil and Zhenjiang Xiashu loess,and was underwent moderate chemical weathering.The contrast of weathering parameters and magnetic susceptibility indicates that during about 250-100 ka,the pedogenic environment of Xianlin profile is divided into four intervals：cold and dry,warm and wet,cold and wet,warm and wet.Our research reflects that the chemical weathering intensity is increasing during this period.The paleoclimate of the middle and lower valley of the Yangtze River area has gradually become warm-wet during about 250-100 ka.The results declare for the increasing of the East Asian summer monsoon.