Geochemical characteristics of major elements and their paleoenvironmental significance of the Xianjingyuan loess in Shandong Province

The loess deposited in the Miaodao Islands has great significance to the revealing of paleoclimatic and paleoenvironmental changes. In this study, we analyzed the compositional characteristics of the major elements of the Xianjingyuan loess on the Nanchangshan island. Combined with the chemical weathering indexes and integrated elemental parameters, we discussed in this paper the characteristics and intensity of chemical weathering and climate changes during the accumulation of Xianjingyuan loess. Also made are comparisons to the Tuoji loess, Pingyin loess and Luochuan loess-palaeosol. It is revealed that: (1) The Xianjingyuan loess is dominated by the major elements of SiO₂, Al₂O₃ and CaO, and the abundance of major elements are in an order of SiO₂＞Al₂O₃＞CaO＞TFe₂O₃＞K₂O＞Na₂O＞MgO＞TiO₂＞P₂O₅＞MnO; (2) Chemical weathering indicators indicated that the Xianjingyuan loess was in an initial stage of chemical weathering; and the integrated element parameters suggest that the region had experienced five times of climatic change from warm and humid to cold and dry, and the climate environment of Xianjingyuan has a good response to the global climate environment; (3) The dust sources and the paleoclimate environment are highly similar to the loess found in Shandong Province, but the regional environment was effected by geographic location and topographic conditions, the obvious difference between Xianjingyuan loess and Pingyin loess suggest that there is difference in dust sources; (4) the difference between the major elements and chemical weathering in Xianjingyuan loess and Luochuan loess-palaeosol owes its origin to the difference of dust sources.