Enrichment mechanism of rare earth elements and yttrium in deep-sea mud of Clarion-Clipperton Region

The deep-sea mud in Clarion-Clipperton region(CC Zones),East Pacific Ocean have a high content of rare earth elements and yttrium(REY).Understanding the REY enrichment mechanism in pelagic sediments is important for seeking deep-sea REY resources.In this paper,samples from piston core WPC1101 station are investigated with high-resolution analysis of the sediment type,particle size,clay minerals and geochemistry.Combined with the results of previous studies and information,this study was to investigate the characteristics and enrichment mechanism of REY in deep-sea mud.The samples from the study area mainly contain pelagic clay and siliceous biological components,with∑REY content mainly between 400 ppm to 1000 ppm.NASC-normalized REY patterns of mud samples from CC Zones display significant negative Ce anomalies,indicating that the authigenic sediments have a major contribution to the REY.According to geochemical statistics,∑REY has good correlation with Al2O3,MnO and P2O5.REY in the deep-sea mud were carried by clay fractions,iron oxides,manganese oxides and phosphates,while the REY fractions in these substances are different for different situations.According to the comprehensive analysis,we proposed that the deep-sea mud from CC Zones with high P content has major contribution to the high REY content.