中文摘要：

根据长江三角洲南部平原12个柱状样（各柱样长2．5m）沉积物中总硫（TS）、总有机碳（TOC）含量、C1-浓度及pH值，计算湖沼平原、三角洲平原和现代潮滩3个沉积地貌区TS／TOC散点回归线的斜率，并分析长江口硫元素分布的主要影响因素，检验TS／TOC在研究区识别咸水、淡水沉积环境的可行性。研究结果显示，三角洲平原的7个剖面（H2～H8）TS／TOC平均值0．026～0．044，TS与TOC具有良好的相关性，回归线斜率0．027；湖沼平原区的3个剖面（H10～H12）TS／TOC平均值为0．029～0．032，TS与TOC回归线斜率为0．037。而位于杭州湾现代潮滩的H9剖面TS／TOC呈现显著高值，平均值为0．130，回归线斜率达到最大值0．117；崇明岛现代潮滩的H1剖面TS／TOC平均值为0．055，回归线斜率为0．054，明显高于前述淡水环境，反映了海水对TS的影响，也显示了TS／TOC指标可能是该区比较有效的咸淡水环境判别工具。另外，长江口的TS／TOC比值和TS-TOC散点回归斜率明显低于世界其他半成水海岸带沉积，指示了大河口淡水径流作用强烈的区域性特征。

英文摘要：

The present paper investigated the total sulfur （TS） content, total organic carbon （TOC） content, chloridion ion concentration and pH value in 12 sediment sections （2.5 m long for each） from different geomorphologic units of the southern Changjiang delta plain. The regression lineslopes of TS/TOC plots were also calculated for sediments from the lacustrine plain, delta plain, and modern tidal fiat. We tend to examine the major factors for sulfur distribution in the Changjiang estuary and assess the feasibility of applying TS-TOC in distinguishing sedimentary environments. The results demonstrate that average values of TS/TOC of sediment sections H2 - H8 from the delta plain vary from 0.026 to 0. 044. There is a significant correlation between TS and TOC and the regression line slope being 0. 027. TS/TOC values are 0. 029 ～ 0. 032 and regression line slope is 0. 037 in sediment sections H10 H12 from the lacustrine plain. TS/TOC is much higher, being 0. 130 in H9 from the modern tidal flat of the Hangzhou Bay. Regression slope is also significantly higher as being 0. 117. For H1 located at the modern tidal flat of Chongming island, the average value of TS/TOC is 0.055 and the regression slope is 0. 054. The distribution of TS/TOC and the regression slope of TS-TOC plots indicates that it could be a useful tool to distinguish sedimentary environments in the Changjiang River delta. In addition, the values of TS/TOC and regression slope of TS-TOC plots of the study area are clear lower than those of other brackish coastal deposits, reflecting the characteristics of large river mouth with huge quantity of freshwa- ter and sediment discharge.