Influence of Phosphatization in REY Geochemistry in Ferromanganese Crusts in Line Islands, Central Pacific

Ferromanganese (Fe-Mn) crusts are potential marine deposits for many high-tech metals and exciting proxies recording the oceanic paleoenvironment. During their growth, phosphatization generally occurs, causing remobilization reorganization of elements minerals in Fe-Mn crusts. Rare earth plus yttrium (REY), well-known critical new emerging technologies, as well valuable geological proxies, important The REY occurrence is closely influenced by processes, which still remain discursive. In this study, textures, structures, geochemistry growth an crust sample (MP2D32A) from Line Islands archipelago were analyzed using multiple microanalysis methods. mainly characterized presence laminated concentric colloforms. Massive fine particles some veins carbonate-rich fluorapatite (CFA) observed old part MP2D32A, demonstrating that underwent phosphatization. phosphatized non-phosphatized layers, CFA veins, display distinctly different PAAS-normalized patterns. Higher contents layer than those suggest positive role enrichment. Moreover, contains higher CFA, implying enrichment not only (oxyhydr)oxides but also other factors, such probable PO43− complexation induced Fe oxyhydroxides. synergistical sorption REY(III) HPO42− ions on oxyhydroxides should facilitate during processes. These fundamental results provide novel insights into influence geochemical behaviors crust.