【作者】 于雯泉；

【导师】 钟少军；

【作者基本信息】 中国科学院研究生院（海洋研究所） ， 海洋地质学， 2006， 博士

【摘要】 本论文以胶州湾李村河口区为研究对象,通过4个沉积柱样的分析测试,对港湾内河口区沉积物中的有机质(TOC)、酸可挥发硫化物(AVS)及重金属的环境响应进行了系统的探讨,发现由于湾内河流流量较小、水动力较弱,且港湾有机生产力较强,只有紧贴河口的细粒(泥质粉砂)区域的有机质才受陆源控制,有机碳含量较高(JZB-2柱平均为1.87%),TOC、AVS与多数重金属(Cd、Cr、Cu、Fe、Pb、Sr、Zn等)呈正相关性,且重金属含量高,反映了在高重金属污染的情况下,有机质对重金属的吸附呈无选择性。而离河口稍远处,沉积物粒度较粗(粉砂),有机碳含量相对较低(JZB-4柱平均为1.02%),C/N大(>>20),C与N的相关性不强,受海、陆双源控制,重金属含量相对较低,TOC仅与Cd、Cu、Sr的活性部分呈正相关,N与Cd、Cr、Pb、Zn的活性部分呈正相关,说明部分重金属组分受陆源有机碳控制,而AVS与Fe、Hg、Zn的SEM部分呈正相关,表明在S的循环中,一些类Fe重金属往往参与其中。并分析了李村河口区的粒度变化特征,并根据有机质、酸可挥发硫化物及重金属的分布规律将河口区三角洲划分为三个区域、五种相带,总结了不同的沉积模式下其不同的环境响应,从而为海陆交互相地区的沉积物早期成岩作用与环境响应研究提供指导与参考。而且在研究的过程中还发现了目前国际通用的沉积物有机碳测定方法中存在着很大的人为误差,并通过系统实验改正了沉积物有机碳的测定方法。更多还原

【Abstract】 Carbon, sulfur and heavy metals are some of the most reactive components of coastal marine sediments during early diagenesis. In this study, we examined the Total Organic Carbon (TOC), organic carbon to nitrogen ratio (C/N), Acid Volatile Sulfide (AVS), and heavy metal contents of four sediment cores collected from the Licun Estuary in the northeast of Jiaozhou Bay near Qingdao, China. Near the entrance of the river, sediment (argillaceous siltstone) TOC content was relatively high (TOC average of JZB-2 core was 1.87%) and was controlled by terrestrial input. The relatively low stream flow, weak water dynamics, and high biological productivity in the water column in this area favored the preservation and burial of organic carbon in the sediment. The concentrations of heavy metals (i.e., Cd, Cr, Cu, Fe, Pb, Sr, Zn, etc.) were high and correlated positively with both TOC and AVS contents. A short distance away from the entrance of the river, sediment was coarser (siltstone) and its TOC content was lower (TOC average of JZB-2 core was 1.02%) than sediment near the entrance. The relatively high C/N ratio (i.e., >>20) and weak C to N correlation indicated that sediment organic carbon content was controlled by both marine and terrestrial sources. The concentrations of heavy metals in sediment were low. The reactive fractions of Cd, Cu and Sr correlated positively with sediment TOC content, while the reactive fractions of Cr, Pb and Zn correlated positively with sediment organic nitrogen. This observation suggested that the mobility of some heavy metals was controlled by terrestrial organic matter. The SEM fractions of Fe and Zn correlated positively with sediment AVS content, indicating strong influence of sulfur cycling on the mobility of this group of heavy metals. In addition, a careful examination of the current methods of sediment organic content determination revealed an important artifact. A revised the method was presented.更多还原