胶州湾沉积环境演变的分析

Analysis of Sedimentary Environmental Evolution of the Jiaozhou Bay

从剖析表征沉积环境演变的生物学、地质动力学以及地球化学指示因子入手,系统总结了近年来胶州湾沉积环境演变研究的进展,揭示了诸如有孔虫、沉积物粒度、生源要素、污染物及有机质等众多指示因子以及它们的相关组合与环境演变的关系。综合分析表明,胶州湾沉积速率较低,属于缓慢淤积的海湾,是一个典型的潮汐汊道系统。胶州湾的沉积环境演变分为4个阶段:陆相、三角洲沼泽相、海陆过渡相和海湾相。在过去的50 a中,特别是近20 a来,由于受人类活动与工业排污的影响,胶州湾的沉积环境发生了显著的变化,海域面积大大减少,陆源输入已经成为胶州湾沉积物的主要来源,沉积速率不断增加,局部海域特别是河口附近污染加重。这些变化都是通过各种生物、地质动力和地球化学因子来综合体现的。

In this paper, the advances in study on sedimentary environmental evolution of the Jiaozhou Bay in recent years are summarized by analyzing indicators in biology, geologic dynamics and geochemistry, and the relationship between different indicators and environmental evolution are revealed. It is shown from the analysis results that the Jiaozhou Bay has a low sedimentation rate, belongs to the slowly silted bay, and is a typical tidal inlet system. The sedimentary enviromental evolution of the Jiaozhou Bay can be divided into four stages, continental facies, delta and swamp facies, land-sea transition facies and bay facies. In the past 50 years, especially in recent 20 years, the sedimentary environment of the Jiaozhou Bay has changed significantly due to the impacts of human activities and discharged industrial pollutants, for example, the sea area has decreased greatly, the input of terrigenous materials has become the main source of the Jiaozhou Bay sediments, the sedimentation rate in the Jiaozhou Bay increased continuously, and the pollution in some sea areas, especially in the estuarine areas, has been aggravated. The above-mentioned environmental changes can all be reflected by different biological, geodynamical and geochemical indicators.