Rare‐Earth Elements in Deep‐Sea Sediments in the South Pacific Gyre: Source Materials and Resource Potentials

Deep-sea sediments enriched in rare-earth elements and yttrium (REY) plus scandium (Sc), termed “REY-rich mud,” have attracted attention as a possible resource for these critical industrial elements. Examples been reported from the western North Pacific, central low-latitude South eastern Pacific. Although previous studies of pelagic clay existence highly REY-rich mud ultraoligotrophic Pacific Gyre, neither source materials nor potentials REY Sc sediment quantified. We analyzed major- trace-element contents bulk Integrated Ocean Drilling Program Holes U1365A to U1370D, drilled Gyre. The elemental relationships suggest that enrichment reflects accumulation biogenic Ca phosphate an environment with low sedimentation rates well tectonic transition depositional environments hydrothermally influenced sites near mid-ocean ridge distal basins far hydrothermal vents. maximum total content 4,662 ppm at Hole U1366C is highest value yet Ocean. REY- Sc-enriched layers most cores Gyre are located deeper beneath seafloor than those elsewhere Ocean, U1367B demonstrates large (1.21 × 104 t/km2 oxides 102 Sc) uppermost 6.5-m interval, making it promising site found