厦门吴冠海岸潮间带沉积物粒度特征及其沉积动力学涵义

Grain size characteristics and sedimentary dynamic significance of surface sediments in intertidal flat of Wuguan,Xiamen

潮滩沉积物的粒度参数可以用来反映沉积物沉积的水动力、沉积物来源和沉积物搬运趋势等环境信息。对厦门吴冠潮间带35个表层样的粒度资料进行分析的结果表明,研究区沉积物类型以黏土质粉砂和粉砂质砂为主;沉积物主要来源于海岸侵蚀物质的输入,随着沉积物向海方向搬运,沉积物粒度参数表现出有规律的变化趋势,即由岸向海粒径具有细化趋势,分选程度变好。与开敞海岸淤泥质潮滩粒度特征相比,研究区的粒度参数组合特征具有明显差异,这可能是由于水动力条件的差异引起的。

Grain size parameters of intertidal flat sediments are related to local sedimentary environments, such as depositional hydrodynamic conditions, sediment sources, sediment transport, etc. Total 35 surface sediment samples were collected in the intertidal flat of Wuguan in September, 2005, and then analyzed using Mastersizer 2000. Seven types of sediments have been identified, the two main sediment types of which are clayey silt and silty sand, with percentages of 42.86% and 34.29% respectively. The sediments in the intertidal flat mainly come from coast erosion. The sediments are sorted better towards the sea and their grain size decreases with the increasing of hydrodynamics. In contrast to the tidal flat on the open coast, the characteristics of grain size parameters and the relationships among these parameters are obviously different clue to different hydrodynamic conditions.