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在长江河口潮滩、分流河道和水下三角洲共获得18个柱样,进行沉积学分析和210Pb测定,并对其中6根柱样进行137Cs测定。经研究发现,长江口外在水深25～30m,122°30′N,31°00′E附近存在一个泥质沉积中心,沉积速率达2.0～6.3cm/yr。另外,在潮滩和涨潮槽也获得较高沉积速率,其中南汇和横沙岛潮滩沉积速率(1.03～1.94cm/yr)高于崇明东滩(0.51～0.76cm/yr),涨潮槽沉积速率也达0.86cm/yr。此外,在石洞口、南汇、九段沙潮滩和三角洲前缘有部分柱样未获沉积速率,推测为沉积环境不稳定或沉积速率过快所致。
A total of 18 column samples were obtained from the tidal flats, distributary channels and subaqueous delta of Yangtze River estuary. Sedimentology analysis and 210Pb determination were carried out. Six of the six columns were analyzed by 137Cs. The study found that there is a muddy sedimentary center near the Changjiang Estuary at water depths of 25-30m, 12230’N and 3100’E, and the deposition rate is 2.0-6.3cm / yr. In addition, higher sedimentation rates were also obtained in tidal flats and tidal flats. Sediment deposition rates (1.03-1.94 cm / yr) in Nanhui and Hengsha Islands were higher than those in Chongming Dongtan (0.51-0.76 cm / yr) The rate also reached 0.86 cm / yr. In addition, some sediment samples were not obtained at Shidongkou, Nanhui, Jiuduansha tidal flats and the delta front, suggesting that the sedimentary environment was unstable or the sedimentation rate was too high.