Journal of Geographical Sciences ›› 2010, Vol. 20 ›› Issue (1): 91-108.doi: 10.1007/s11442-010-0091-3

• Geomorphology • Previous Articles     Next Articles

Distribution of 137Cs and 210Pb in sediments of tidal flats in north Jiangsu Province

LIU Zhiyong, PAN Shaoming, LIU Xuying, GAO Jianhua   

  1. Ministry of Education Key laboratory of Coastal and Island Development, Nanjing University, Nanjing 210093, China
  • Received:2008-10-29 Revised:2009-05-06 Online:2010-02-15 Published:2010-02-15
  • Contact: Pan Shaoming, E-mail: Span@nju.edu.cn E-mail:Span@nju.edu.cn
  • About author:Liu Zhiyong (1981–), Ph.D Candidate, specialized in coastal environment. E-mail: yongjxu@163.com
  • Supported by:

    National Basic Research Program of China, No.2002CB412401; Scientific Research Foundation of Graduate School of Nanjing University; National Natural Science Foundation of China, No.40776023

Abstract:

Seven cores were collected from different sediment zones of tidal flats at Xinyanggang in north Jiangsu province in August 2007. Sediment grain-size distribution and radioisotopes of 137Cs and 210Pb analysis were carried out for these cores. Sediment rates of the cores and radioisotopes distribution in surface sediment in different zones of the tidal flat were calculated from the 137Cs and 210Pb activities in sediments cores. The results indicated that each tidal zone had experienced different evolution phases, hydrological dynamics in the tidal flats made the grain-size of the surface sediment change gradually. 137Cs and 210Pb activities on the superficial layer of the cores varied spatially and the reason was discussed. On tidal flats, the fluctuation of 137Cs and 210Pb activities in the cores reflected the special sedimentary characteristics. Vegetation affects the grain-size distribution and the vertical profiles of 137Cs and 210Pb in the upper depths. 137Cs and 210Pb chronology got the comparable average sediment rates on the tidal flat. The characteristics of 137Cs and 210Pb in the cores reflected various depositional dynamical environments in different tidal zones and gave information on the different evolvement phases of the tidal zones. Based on the information of grain-size distribution, texture of the cores, sediment rates and topography, the evolution lines of the tidal flat were reconstructed.

Key words: tidal flats, grain-size information, 137Cs and 210Pb dating, sediment rates, north Jiangsu province