镇江下蜀土剖面的化学风化强度与元素迁移特征

• 作 者: 陈英勇 李徐生 韩志勇 杨守业 王永波 杨达源
• 机 构: School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing 210093, ChinaSchool of
• 出 处: 地理学报（英文版）
• 发表日期: 2008年3期
• 关键词: Xiashu loess chemical weathering element migration Zhenjiang

The chemical weathering intensity and element migration features of the Xiashu loess profile in Zhenjiang are studied in this paper. (1) The Xiashu loess profile underwent moderate chemical weathering. It seems that the precipitation is a more important factor than the temperature in controlling the process of the chemical weathering. (2) The major elements such as Si, K, Na, Ca, Mg, Mn and P were migrated and leached, while the elements Fe and Ti were slightly enriched. The migration features of the major elements reveal that the Xiashu loess finished the primary process of chemical weathering characterized by leaching of Ca and Na, and almost reached the secondary process characterized by leaching of K. Except the elements Sr and Ga, other trace elements such as Th, Ba, Cu, Zn, Co, Ni, Cr and V were enriched. It might be caused by both the biogeochemical process and the adsorption of trace elements by clay mineral and organic materials. (3) The difference of element migration down the Xiashu loess profile reveals that the climate was warm and wet at the early-middle stage of the middle Pleistocene. At the end of the middle Pleistocene, it became dry and cool. At the early stage of the Late Pleistocene, the paleoclimate became warm and wet again. As a whole, the paleoclimate generally became drier and cooler in this region from the beginning of the middle Pleistocene.