Geochemical Characteristics Of The Yalu River Surface Sediments And Their Influence On Sediment Distribution Of The North Yellow Sea

Based on the geochemistry, particle size grading, multivariate statistical methods,analyzed6samples from yalu river estuary and42samples from north yellow sea, todiscuss the geochemistry characteristics of the yalu river sediment and its influence onthe sediment distribution of the north yellow sea.Analysis showed that: theexperimental treatment (removal of organic matter and carbonate) had a greaterinfluence on the characteristics of grain size and had little influence on characteristicsof elements. With high K2O content is the remarkable feature of the Yalu river surfacesamples, Al2O3, Fe2O3, MgO,MnO, TiO2, P2O5six major elements in the <8micronsfraction within the highest levels, and there was a trend toward increased with thedecrease of the fraction content;CaO, Na2O two elements in the <8microns fractionwithin the content is the lowest, the content in coarse silt and sand is high;the contentof K2O in each fraction distribution is relatively similar. Elements content in8-30microns fraction have the most minor differences,so geochemical characteristics ofthe sediment in8-30microns fraction is most likely to represent the yalu riversediment characteristics.According the CIA index,the weathering degree of sedimentsfrom Yalu river estuary to Dayanghe estuary decline after arise, the sediment of>63microns,30-63microns, and8-30microns have the similar weathering degree,significantly lower than the <8microns graded sediment in weathering degree. Toextract two factors thay control elements distribution by principal factor analysis,, thecumulative variance contribution was87.22%, and the analysis showed that thedistribution of elements in yalu river estuary is mainly controlled by weatheringintensity and biochemistry authigenesis influence.With the decline of the grain size,the content of rare earth elements decline after arise, in8-30microns fraction withinthe highest levels.In>63microns fraction was positively europium anomalies withinthe other three grade for moderate negative anomaly, cerium hardly display abnormal.The distribution difference of constant elements in north yellow sea surfacesamples in different graded is more bigger, correlation analysis showed that thesamples after grading, the control effect of particle size distribution of elementsgreatly abate, source control factors and weathering intensity became morestrengthened, cluster analysis showed that the sample clustering number reduced withgrain size decreases.K2O and TiO2are well indicators to identify the sedimentdistribution from the yalu river and the Yellow river and confirm the existence of theyellow sea warm current that made an impact on sediment east-west transportation, the element indicates effect in>63microns,30-63microns, and8-30micronssediment is good, provenance indicates effect is not obvious in<8microns sedimentbecause of stronger mixing by surface current.With the decrease of the grain size, rareearth element content in the north yellow sea surface sample first increase in decline,in the30-63microns fraction within the highest levels.The value of δEu changes morebigger in>63microns sediment,other three fractions showed more apparent negativeeuropium anomaly, four graded almost did not show the cerium anomaly. Content ofrare earth elements in>63microns,30-63microns, and8to30microns sedimentsshow that the higher in northeast and lower in southwest, and the high value area ofrare earth elements content showed negative europium anomaly, and is low in the areato show the positive europium anomalies. In addition, the REE distribution in thesethree grades sediment is also a good indicator, the yalu river is the main provenance inthe northeast area, greatly influenced by the input sediment of the Yellow River in thewest area and the middle area is combined impact by the yalu river, the Yellow Riverand the warm current,the indicate function of <8microns fraction sediments is alsonot obvious.