The content and distribution pattern of rare earth elements(REEs)in surface sediments from the Eastern and Western Pacifi c Ocean,the Northern and Southern Atlantic Ocean,and the Southwestern Indian Ocean were explore...The content and distribution pattern of rare earth elements(REEs)in surface sediments from the Eastern and Western Pacifi c Ocean,the Northern and Southern Atlantic Ocean,and the Southwestern Indian Ocean were explored and the resources and geochemical characteristics of REEs in deep-ocean sediments from diff erent oceans were studied.The total REE abundances(ΣREE)in the diff erent oceans ranged as follows:Eastern Pacifi c,56.88–500.02μg/g;Western Pacifi c,290.68–439.94μg/g;Northern Atlantic,55.33–154.90μg/g;Southern Atlantic,40.83–69.30μg/g;and Southwestern Indian Ocean,20.24–64.76μg/g.Their corresponding LREE(La-Eu)/HREE(Gd-Lu)average values were 5.18,5.86,9.01,5.21,and 4.59,which indicated that the light REEs were all evidently enriched.δEu andδCe showed slight Eu-negative anomalies and signifi cant Ce-positive anomalies in all sediments.Although the contents of REEs in the sediments varied among the diff erent oceans,the distribution patterns of REEs were similar,and the correlation coeffi cient was greater than 0.9290.In the Eastern Pacifi c sediments,ΣREE showed a signifi cantly positive correlation with Co,Cu,Zn,Mn,Mo and a weak correlation with Fe.In the Western Pacifi c and Southern Atlantic sediments,ΣREE presented no obvious correlation and a weakly negative correlation with Co,Cu,Zn,Mn,Mo and Fe,respectively.ΣREE in the Southwestern Indian Ocean sediments positively correlated with Cu,Zn,Mn,Mo,Fe,and had a weakly negative correlation with Co.展开更多
The rare earth element（REE） data from the Paleoproterozoic Bijawar basin,Sonrai phosphorites were used to interpret the depositional conditions of the phosphorites.The post archean Australian shales（PAAS） normaliz...The rare earth element（REE） data from the Paleoproterozoic Bijawar basin,Sonrai phosphorites were used to interpret the depositional conditions of the phosphorites.The post archean Australian shales（PAAS） normalized REE patterns of the Sonrai phosphorites were characterized by negative Ce and positive Eu anomalies.Middle rare earth elements（MREE）-enrichment was a characteristic feature.Phosphorites showing the diagenetic effects on the REE patterns were limited.The observed Eu anomaly was indicative of an anoxic（or sulphate reducing） diagenetic environment of phosphate formation.Mixing of sea water and upwelling during the Paleoproterozoic was responsible for the recording of positive Eu and negative Ce anomalies in the Sonrai phosphorites.展开更多
基金Supported by the Basic Scientifi c Fund for National Public Research Institutes of China(No.2020Q10)and the China Ocean Mineral Resources R&D Association(Nos.DY135-E2-1-07,DY135-E2-4)。
文摘The content and distribution pattern of rare earth elements(REEs)in surface sediments from the Eastern and Western Pacifi c Ocean,the Northern and Southern Atlantic Ocean,and the Southwestern Indian Ocean were explored and the resources and geochemical characteristics of REEs in deep-ocean sediments from diff erent oceans were studied.The total REE abundances(ΣREE)in the diff erent oceans ranged as follows:Eastern Pacifi c,56.88–500.02μg/g;Western Pacifi c,290.68–439.94μg/g;Northern Atlantic,55.33–154.90μg/g;Southern Atlantic,40.83–69.30μg/g;and Southwestern Indian Ocean,20.24–64.76μg/g.Their corresponding LREE(La-Eu)/HREE(Gd-Lu)average values were 5.18,5.86,9.01,5.21,and 4.59,which indicated that the light REEs were all evidently enriched.δEu andδCe showed slight Eu-negative anomalies and signifi cant Ce-positive anomalies in all sediments.Although the contents of REEs in the sediments varied among the diff erent oceans,the distribution patterns of REEs were similar,and the correlation coeffi cient was greater than 0.9290.In the Eastern Pacifi c sediments,ΣREE showed a signifi cantly positive correlation with Co,Cu,Zn,Mn,Mo and a weak correlation with Fe.In the Western Pacifi c and Southern Atlantic sediments,ΣREE presented no obvious correlation and a weakly negative correlation with Co,Cu,Zn,Mn,Mo and Fe,respectively.ΣREE in the Southwestern Indian Ocean sediments positively correlated with Cu,Zn,Mn,Mo,Fe,and had a weakly negative correlation with Co.
文摘The rare earth element（REE） data from the Paleoproterozoic Bijawar basin,Sonrai phosphorites were used to interpret the depositional conditions of the phosphorites.The post archean Australian shales（PAAS） normalized REE patterns of the Sonrai phosphorites were characterized by negative Ce and positive Eu anomalies.Middle rare earth elements（MREE）-enrichment was a characteristic feature.Phosphorites showing the diagenetic effects on the REE patterns were limited.The observed Eu anomaly was indicative of an anoxic（or sulphate reducing） diagenetic environment of phosphate formation.Mixing of sea water and upwelling during the Paleoproterozoic was responsible for the recording of positive Eu and negative Ce anomalies in the Sonrai phosphorites.
