莱州湾表层沉积物粒度和黏土矿物分布特征与运移趋势分析

Surface sediment grain size and clay minerals distribution and transport in the Laizhou Bay

运用粒度参数分析、黏土矿物含量分析、Flemming三角图示法和Gao-Collins二维的"粒度趋势分析"等方法,对采自莱州湾海域的表层沉积物样品和黏土矿物样品进行分析,了解了该研究区域的沉积环境及沉积物的运移趋势。研究区由岸向海沉积物类型大致依次为砂-粉砂质砂-砂质粉砂-粉砂-黏土质粉砂,并且研究区表层沉积物在近岸区域呈现较为明显的平行岸线的条带状特征;同时沉积物的平均粒径、分选系数、偏态、峰态等粒度参数也呈现出良好的正相关性或负相关性;研究区黏土矿物为伊利石、蒙脱石、绿泥石、高岭石,除伊利石分布大致为黄河三角洲近岸低,向研究区东北方向逐渐升高外,其余的黏土矿物都表现出了近岸高,远海低的分布特征,且主要物源为黄河物质输入。Flemming三角图研究区所有采样点大部分分布在Ⅱ区,少部分分布在Ⅲ区,说明研究区整体水动力较强;采样点在A—E区均有分布,但在C、D两区分布最多,说明研究区沉积物粒径较集中。研究区表层沉积物整体呈由岸向海输运的趋势,具体来看,黄河沉积物入海后向北、向东、向南运移,研究区内沉积物的来源是黄河输沙以及周围入海的小河流的输沙和沿岸冲刷的物质。

In this paper, surface sediment samples and clay mineral samples collected from the Laizhou Bay were analyzed using particle size analysis, clay mineral content analysis, Flemming triangle mapping method, and Gao- Collins two-dimensional grain size trend analysis to study the sedimentary environment and sediment transport trend of the study area. The types of sediments in the study area are sandy silt, sandy sand, and clayey silt from the shore to the sea, and the surface sediments show a stripe-like characteristic of the parallel shoreline in the coastal area. Meanwhile, the average grain size, sorting coefficient, skewness, and peak state of the sediments also show good positive correlation or negative correlation. The clay minerals in the study area are illite, montmorillonite, chlorite, and kaolinite, and the distribution of illite is rather lower in the Yellow River Delta, but gradually increases toward the northeastern part of the study area. The rest of the clay minerals show high and low coastal sea distribution characteristics, mainly because of the Yellow River material input. In the study area of the Flemming triangulation, the sample points are mostly distributed in the area and least distributed in the area Ⅱ and least distributed Ⅲ, indicating that the overall hydrodynamics of the study area is strong. The sample points are distributed in areas A to E, but are mostly distributed in areas C and D, indicating that the sediments are more concentrated in the study area. Generally, the sediments are transported from shore to sea. Specifically, the Yellow River sediments migrate northward, eastward, and southward. The sources of sediments are the Yellow River, surrounding rivers sediments transport, and coastal erosion around the study area.