Journal of Geographical Sciences ›› 2008, Vol. 18 ›› Issue (3): 341-352.doi: 10.1007/s11442-008-0341-9

• Climate and Environmental Change • Previous Articles     Next Articles

Chemical weathering intensity and element migration features of the Xiashu loess profile in Zhenjiang, Jiangsu Province

CHEN Yingyong1, LI Xusheng1,2, HAN Zhiyong1, YANG Shouye3, WANG Yongbo1, YANG Dayuan1   

  1. 1. School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing 210093, China|
    2. State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, CAS, Xi’an 710075, China|
    3. State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092, China
  • Received:2008-02-27 Revised:2008-05-29 Online:2008-09-25 Published:2010-09-18
  • Supported by:

    National Natural Science Foundation of China, No.40401006; Open Foundation of State Key Laboratory of Loess and Quaternary Geology, No.SKLLQG0304; Experimental Foundation of Nanjing University

Abstract:

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.

Key words: Xiashu loess, chemical weathering, element migration, Zhenjiang