title: [Mineralogy and genesis of mixed-layer clay minerals in the Jiujiang net-like red soil].
abstract: 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.
authors.affiliation: Faculty of Earth Sciences, China University of Geosciences, Wuhan 430074, China. yinke1984@qq.com
authors.forename: Ke
authors.initials: K
authors.lastname: Yin
authors.forename: Han-Lie
authors.initials: HL
authors.lastname: Hong
authors.forename: Rong-Biao
authors.initials: RB
authors.lastname: Li
authors.forename: Wen
authors.initials: W
authors.lastname: Han
authors.forename: Yu
authors.initials: Y
authors.lastname: Wu
authors.forename: Wen-Peng
authors.initials: WP
authors.lastname: Gao
authors.forename: Jin-Sheng
authors.initials: JS
authors.lastname: Jia