Journal of Geographical Sciences ›› 2008, Vol. 18 ›› Issue (1): 37-45.doi: 10.1007/s11442-008-0037-1

• Climate and Environmental Change • Previous Articles     Next Articles

Environmental evolution in the salt-water intru-sion area south of Laizhou Bay since late Pleisto-cene

ZHANG Zulu1, LIU Enfeng2, ZHANG Yan1, XIN Liangjie3   

  1. 1. Geography Department of Shandong Normal University, Jinan 250014, China|
    2. Nanjing Institute of Geography &|Limnology, CAS, Nanjing 210008, China|
    3. Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China
  • Received:2007-06-29 Revised:2007-09-15 Online:2008-02-25 Published:2008-02-25
  • Supported by:

    National Natural Science Foundation of China, No.40471122

Abstract:

The south coastal plain of Laizhou Bay is one of the typical salt-water intrusion areas in China, the occurrence and development of which was closely related with the pa-laeoenvironment evolution. Systematic analyses of pollen, foraminifera and grain size com-position based on 14C and luminescence dating from two sediment cores were performed for the purpose of understanding the salt-water intrusion in the coastal plain of Laizhou Bay from the perspective of environmental evolution since late Pleistocene. It could be classified into seven evolution stages since 120 kaBP: 120–85 kaBP was a transition period from cold to warm; 85–76 kaBP was a period with warm and wet climate having swamp lakes developed in the lower reaches of the Weihe River, south coastal plain of Laizhou Bay; 76–50 kaBP was characterized by grassland vegetation and coarse sediments in terrestrial environment, which was the early stage of Dali Ice-Age; 50–24 kaBP was a period with alternate sea deposition in the south coastal plain of Laizhou Bay; 24–10 kaBP was the late stage of Dali Ice-Age with coldest period of Quaternary, the south coastal plain of Laizhou Bay was dry grassland and loess deposition environment; 10–4 kaBP was another warm and wet climate period, sea level was high and regressed at 4 kaBP; and has been the modern sedimentary environment since 4 kaBP. Among the three warm stages, including 85–76 kaBP, 50–24 kaBP and 10–4 kaBP, corresponded to late Yangkou, Guangrao and Kenli seawater transgression respec-tively. The duration of the latter one in south coastal plain of Laizhou Bay was longer than that in west coast of Bohai Sea and east coast of Laizhou Bay. The three periods of seawater transgression formed the foundation of salt-water intrusion in this area.

Key words: environmental evolution, salt-water intrusion, late Pleistocene, south coastal plain of Laizhou Bay, China