湛江湾沉积物稀土元素特征及其地质意义OA

A systematic comparative analysis of rare earth elements(REEs)in 33 sediment samples collected in 2022 from Zhanjiang Bay was conducted to reveal their distribution characteristics,influencing factors,main ma-terial sources,and transport mechanisms.Results show that the average size of the sediment particles was 21.21 μm.Most of them were made up of silt and sandy silt.The total REE content(ΣREE)ranged from 114.06 to 286.83 μg/g,with an average of 208.83 μg/g.The sediments featured light REEs(LREE)enrichment,flat heavy REEs(HREE)pattern,pronounced negative Eu anomaly,and absence of significant cerium(Ce)anomaly.Correl-ation analysis between ΣREE with grain size,chemical index of alteration(CIA),and major mineral elements re-vealed that the REE distribution of this study area is closely related to grain size,CIA,and provenance.The chon-drite-normalized REE patterns of Zhanjiang Bay sediments are similar to those of coastal granites in Guangdong and the upper continental crust of China,indicating strong terrigenous influence.Provenance discrimination by means of δEu-(La/Yb)N and(Gd/Yb)N-(La/Yb)N diagrams that were calculated from chondrite-normalized values,suggested that the sediments of Zhanjiang Bay are mainly derived from a mixture of granite or granitic continent-al crust,the surrounding basaltic rocks of Zhanjiang Bay,and the Quaternary sediments.In addition,our prelimin-ary finding indicates that the relative contributions to REE enrichment in the sediments of Zhanjiang Bay are likely changing gradually.