浙江近海表层沉积物粒度参数图解法和矩法计算成果的对比研究

Comparative Study on the Graphic and Moment Methods Results for Calculating the Grain Size Parameters of Surface Sediments in the Zhejiang Offshore Area

摘要: 海底沉积物采用矩法计算粒度参数逐渐普遍，根据浙江近海表层沉积物采样测试资料，对研究区图解法和矩法粒度参数结果进行对比研究。结果表明：浙江近海表层沉积物图解法与矩法得出的平均粒径相关性显著，可以通用，分选系数能够相互换算，偏态和峰态相关性较差，在一定程度上可以互相转换。将沉积物分为砂质沉积、混合沉积和泥质沉积，针对特定的沉积物类型，两种方法的粒度参数对比仍有一定规律，可以建立转换关系。砂质沉积粒级较为集中，粒级分布曲线较为接近正态分布，其偏态和峰态相关性较高，而对于混合沉积和泥质沉积，粒级分布曲线比较复杂多变，尾部含量较高，造成矩法和图解法结果差异较大，二者的换算关系较差。图解法与矩法计算成果的转换关系可以用于该区沉积特征和沉积环境的研究。

Abstract: The use of the moment method to calculate the grain-size parameters of seafloor sediments is gradually becoming common, and the results of the graphic method and the moment method were compared in the study area according to the sampling and testing data of the surface sediments in the Zhejiang offshore area. The results show that the grain size derived from the graphic method and the moment method are significantly correlated and can be exchanged, the sorting coefficients can be converted to each other, and the correlations between the skewness and kurtosis are relatively poor, which can be converted to each other to a certain extent. Divide the surface sediments in the study area into sandy sediment, mixed sediment and mud sediment. For a specific sediment type, there are still certain patterns in comparing the results of two methods, which can be used to establish conversion relationships. The grain size of sandy sediment is more concentrated, the grain size distribution curve is closer to normal distribution, and its skewness and kurtosis correlation is higher, while for mixed sediment and mud sediment, the grain size distribution curve is more complicated and variable, and the tail content is higher, which results in the big difference between the results of the moment method and the graphic method, and the conversion relationship between the two methods is poor. The conversion relationship between the results calculated by the graphic method and the moment method can be used for the study of sedimentary characteristics and depositional environment in this area.