Geochemical characteristics and palaeoclimate significance of the Quaternary laterite of Tutan section in Poyang Lake region, northern Jiangxi Province

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 de_veloped vermicular laterite layer,the weakly developed vermicular laterite layer,the very weakly devel_oped 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 lay_ers of Tutang section are quite coincident in particle size and geochemical characteristics,and they all ex_perienced 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 leac_hin