Grain Size And Geochemical Characteristics Of Surface Sediments In Biliu Estuary,Liaodong Peninsula

Located between 122°18'E--122°54'E and 39°28'N--40°21'N,the Biliu estuary is an important river that flows into the sea only in liaodong Peninsula.It has developed a broad intertidal zone and contains abundant sedimentary information.To brigitte flow sedimentary characteristics,sedimentary mechanism of estuarine intertidal zone and material sources for further in-depth research,this article selects nine sections,a total of 27 in the surface sediment samples,by measuring the sediment grain size,major elements,trace elements,organic elements such as index in combination with multivariate statistical method,flow river surface sediment particle size of garden and geochemical characteristics,The factors affecting the deposition process are discussed and the following conclusions are drawn:(1)The surface sediments of biliu estuary consist of sand,silty sand and sandy silt,among which the content of sandy silt is the most,the content of silty sand is less and the content of sand is the least.The average particle size of sediment is 4.28?,the average sorting coefficient is 1.56,and the average kurtosis is 1.45.The sediment is mainly medium to sharp,and the average skewness is 0.28,which is positive skewness and polar skewness,and concentrated in the coarse end.The cumulative probability curve of sediment is characterized by a typical three-stage transport mode,which is mainly carried out in the form of creep,and suspension and saltation components account for a small proportion.The frequency curve of grain size is dominated by single peak,and coarse grain is the dominant grain size.The grain size characteristics of surface sediments in the Biliu estuary indicate that the hydrodynamic force is strong,the sedimentary environment is complex,and the materials are mainly from terrestrial sources.(2)The spatial distribution of the major elements in the surface sediments of The Biliu estuary shows a certain regularity.SiO₂,CaO,MgO and Na₂O show a decreasing trend from shore to sea,while AL₂O₃,Fe₂O₃,K₂O and TiO₂show an increasing trend from shore to sea.Through comparative analysis,it is found that the elemental composition of the sediments is similar to that of the sediments in the shallow sea of China.The correlation analysis shows that the correlation between the sediment major elements and average grain size is weak and the degree of grain size control is low,indicating that the hydrodynamic force and sedimentary environment in the study area are complex.(3)The spatial distribution of trace elements in the surface sediments of Biliu estuary has a certain regularity.Mn,Sr,Cu,Zn,Ni and Cr decrease from shore to sea,while Ba,Zr,Rb and Pb increase from shore to sea.Through comparative analysis,it is found that the contents of trace elements in sediments are closest to the background values of soil in Liaoning province.The correlation analysis showed that Mn,Sr,Ba,Cr had poor correlation with the average grain size of sediments,indicating that human disturbance was strong in the intertidal zone of Biliu estuary.In trace elements,the pollution degree of heavy metal elements is low,but the content of Ni and Cr is high,which should be paid attention to.(4)The average organic carbon content in the surface sediments of the Biliu estuary is0.44%,and the spatial distribution is increasing from land to sea.Through correlation analysis,it is found that sediment organic carbon is negatively correlated with sand composition percentage,and positively correlated with silt composition percentage,clay composition percentage,average particle size and sorting coefficient,indicating that the sorting coefficient in sediment has a strong indicator effect on organic carbon,while clay composition has a weak indicator effect on organic carbon.By analyzing the stable carbon isotope and C/N value of the sediments,it is found that the source of organic matter in the sediments of Biliu estuary is more Marine,but it is greatly affected by the terrigenous input of runoff,and there are terrigenous organic matter components mixed.