Mineralogy and Genesis of Mixed-Layer Clay Minerals in the Jiujiang Net-Like Red Soil
YIN Ke1, HONG Han-lie1*, LI Rong-biao1, 2, HAN Wen1, WU Yu3, GAO Wen-peng1，JIA Jin-sheng1, 4
1. Faculty of Earth Sciences，China University of Geosciences，Wuhan 430074，China 2. Institute of Tourism, Kaili University，Kaili 556000，China 3. Institute of Jewellery，China University of Geosciences，Wuhan 430074，China 4. Zhejiang No. 3 Geological Party，Jinhua 321001，China
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.
Key words：Net-like red soil;Jiujiang;Early-mid Pleistocene;Mixed-layer clay minerals;Mineralogy and genesis
[1] ZHU Li-dong，ZHOU Shang-zhe, LI Feng-quan, et al(朱丽东，周尚哲，李凤全，等). Geochimica(地球化学)，2007, 36(3): 295. [2] Singer A. Earth Science Reviews，1980, 15(4): 303. [3] XIONG Shang-fa，DING Zhong-li，LIU Dong-sheng(熊尚发，丁仲礼，刘东生). Chinese Science Bulletin(科学通报)，2000，45(12): 1317. [4] ZHANG Ming-kui(章明奎). Journal of Zhejiang University(Agriculture and Life Science)(浙江大学学报·农业与生命科学版)，2000, 26(1): 22. [5] Yin Q, Guo Z. Chinese Science Bulletin(科学通报)，2006，51(2): 213. [6] Srivastava P, Parkash B, Pal D K. Quaternary Research，1998，50(3): 230. [7] HE Ji-zheng，LI Xue-yuan，XU Feng-lin，et al(贺纪正，李学垣，徐凤琳，等). Chinese Science Bulletin(科学通报)，1993，38(22): 2096. [8] Xu F, Li X, Liu F, et al. Journal of Huazhong Agriculture University，1991，10(3): 274. [9] HUANG Li，HONG Jun，LIU Fan，et al(黄 丽，洪 军，刘 凡，等). Acta Mineralogiga Sinica(矿物学报)，2003，23(3): 221. [10] Madejova J. Vibrational Spectroscopy，2003，31(1): 1. [11] Nurcholis M. Australia: 19th World Congress of Soil Science, Soil Solutions for a Changing World，2010. [12] Kahle M, Kleber M, Jahn R. Geoderma，2002，109(3-4): 191. [13] Hong H, Churchman G J, Gu Y, et al. Geoderma，2012，(173-174): 75. [14] Famer V C. Mineralogical Society，London，1974. 331. [15] Nieto F, Ortega-Huertas M, Peacor D R, et al. Clays and Clay Minerals，1996，44(3): 304. [16] YE Wei，ZHU Li-dong，LI Feng-quan，et al(叶 玮，朱丽东，李凤全，等). Acta Pedologiga Sinica(土壤学报)，2008，45(3): 385.
