Geochemical characteristics and palaeoclimate significanceof the Quaternary laterite of Tutan section in Poyang Lake region,northern Jiangxi Province
Ling Chaohao1,2, Long Jin1,2, Jia Yulian1,2, Hong Yijun1,2, Xu Chuanqi1,2, Wang Pengling3
1 School of Geography and Environment,Jiangxi Normal University,Nanchang 330022,Jiangxi; 2 Key Laboratory of Poyang Lake Wetland and Watershed Research,Ministry of Education,Nanchang 330022,Jiangxi; 3 Laboratory for Climate Studies,China Meteorological Administration,Beijing 100081
Abstract：The Quaternary laterite was developed in the Tutang section in Poyang Lake region,northern Jiangxi Province,and it was divided into four layers from bottom to top, including the highly developed vermicular laterite layer, the weakly developed vermicular laterite layer, the very weakly developed vermicular laterite layer, the homogenous laterite layer and the Xiashu loess layer. The geochemical characteristics and palaeoclimate of Tutang section was analyzed based on the major element,grain size and chronological data from former researchers,and the conclusions were drawn as follows: (1)All layers of Tutang section are quite coincident in particle size and geochemical characteristics, and they all experienced an intense chemical weathering process. (2)As for the degree of weathering,the Xiashu loess is in the primary stage by leaching Ca and Na;the homogenous laterite almost reaches the secondary stage by leaching K; the very weakly developed vermicular laterite almost finishes the secondary stage by leaching K,and begins to leach Si; the vermicular laterite has been in the late stage by leaching Si. In terms of migration ability,the major elements are ranked as follows: Na2O>MnO2>CaO>P2O5>MgO>K2O>SiO2>Al2O3>TiO2>Fe2O3. (3)The climate of the Poyang Lake region in northern Jiangxi Province since the Middle Pleistocene changed from warm-wet to cool-dry generally,and the alternate dry and wet fluctuations were oprious, which suggested that the strong eluviation and alternate dry and wet fluctuations are the important driving factors to form the vermicular laterite.
Ling Chaohao,Long Jin,Jia Yulian et al. Geochemical characteristics and palaeoclimate significanceof the Quaternary laterite of Tutan section in Poyang Lake region,northern Jiangxi Province[J]. JOPC, 2015, 17(5): 699-708.
