Yin Ke, Hong Han-Lie, Li Rong-Biao, Han Wen, Wu Yu, Gao Wen-Peng, Jia Jin-Sheng
Faculty of Earth Sciences, China University of Geosciences, Wuhan 430074, China.
Guang Pu Xue Yu Guang Pu Fen Xi. 2012 Oct;32(10):2765-9.
Mineralogy and genesis were investigated using X-ray diffraction (XRD), Fourier infrared absorption spectroscopy (FTIR) and high resolution transmission electron microscopy (HRTEM) to understand the mineralogy and its genesis significance of mixed-layer clay minerals in Jiujiang red soil section. XRD and FTIR results show that the net-like red soil sediments are composed of illite, kaolinite, minor smectite and mixed-layer illite-smectite and minor mixed-layer kaolinite-smectite. HRTEM observation indicates that some smectite layers have transformed into kaolinite layers in net-like red soil. Mixed-layer illite-smectite is a transition phase of illite transforming into smectite, and mixed-layer kaolinite-smectite is a transitional product relative to kaolinite and smectite. The occurrence of two mixed-layer clay species suggests that the weathering sequence of clay minerals in net-like red soil traversed from illite to mixed-layer illite-smectite to smectite to mixed-layer kaolinite-smectite to kaolinite, which indicates that net-like red soil formed under a warm and humid climate with strengthening of weathering.
利用X射线衍射（XRD）、傅里叶红外吸收光谱（FTIR）和高分辨率透射电子显微镜（HRTEM）对矿物学和成因进行了研究，以了解九江红土剖面中混合层粘土矿物的矿物学及其成因意义。XRD和FTIR结果表明，网状红土沉积物由伊利石、高岭石、少量蒙脱石以及伊利石-蒙脱石混合层和少量高岭石-蒙脱石混合层组成。HRTEM观察表明，在网状红土中一些蒙脱石层已转变为高岭石层。伊利石-蒙脱石混合层是伊利石向蒙脱石转变的过渡阶段，高岭石-蒙脱石混合层是相对于高岭石和蒙脱石的过渡产物。两种混合层粘土矿物的出现表明，网状红土中粘土矿物的风化顺序是从伊利石到伊利石-蒙脱石混合层到蒙脱石到高岭石-蒙脱石混合层到高岭石，这表明网状红土是在温暖湿润气候下形成的，且风化作用不断增强。
