中文摘要：

由黄土-红黏土序列组成的风尘沉积是全球最完整、最连续的陆相古气候载体之一,蕴含了丰富的东亚古季风信息。解读黄土记录的信息以及透彻理解黄土替代指标与古气候的内在联系,都需要从纳米尺度揭示黄土成壤作用过程中碎屑矿物、成壤自生矿物形成与演化。本文利用高分辨透射电镜和场发射扫描电镜,研究了风尘沉积物中磁铁矿氧化的粒径制约、自生磁赤铁矿形成机制,建立了古土壤磁化率增强的成因矿物学理论,为磁化率与古气候的内在联系奠定了矿物基础;发现了第四纪黄土中广泛分布纳米棒状方解石及其含量和微结构显著的规律变化,从生物诱导矿化理论阐述了其形成机制;查明了凹凸棒石在黄土-红黏土序列中的分布规律,提出了古气候变化的黏土矿物响应机制。

英文摘要：

Chinese loess-red clay is widely accepted as a unique terrestrial archive of the paleo-climate change and is comparable with deep-sea sediments. In order to better understand the natural relationship between the eolian sequence and paleoclimate,eolian and authigenic minerals should be studied at nanometer scale for revealing the genesis and evolution of clastic and pedogenic minerals in the process of pedogenesis of loess. By using advanced high-resolution transmission electron microscopy（ HRTEM） and field emission scan electron microscope（ FESEM）,we have revealed mechanisms of constraint on size of oxidation of magnetite and formation of authigenic maghemite in the eolian sediments,established genetic mineralogical theory on the enhancement of magnetic susceptibility for paleosol,settled mineralogical base for establishing internal relationship between magnetic susceptibility and paleoclimate,discovered widely distributed nanorod calcite in Quaternary loess,noticed the regularly variation in content and microstructure of the nanorod calcite,elaborated the formation mechanism of the nanorod calcite based on the biologically induced mineralization（ BIM） theory,found out the distribution regularity of attapulgite in the loess-red clay sequence,and finally proposed response mechanism of clay minerals to the paleoclimate change in this paper.