Yu Fu, Fei Huang, Xiaoming Sun, Xiaodong Jiang, Jieyun Chen, Rui Wang, Haoyang Zhou, Andrew P. Roberts
Abstract Rare earth elements and yttrium (REY) are critical for advanced technological and environmental applications. REY‐enriched deep‐sea sediments have attracted attention as significant potential REY resources. However, efficient identification of these deposits in the open oceans is a persistent challenge. From integrated chemical leaching experiments and geochemical and rock magnetic analyses of two Eastern Pacific Ocean sediment cores, we find a coupled evolution between magnetic signatures and REY concentrations in sediment profiles. Apatite and Fe‐Mn (oxy)hydroxides are the primary REY carriers, while biogenic magnetite dominates the magnetic mineral assemblage. We elucidate here mechanistic linkages between mineral magnetic signals and REY enrichment, demonstrating their shared dependence on deep‐sea productivity cycles and redox dynamics. We propose that systematic magnetic property analyses could serve as a novel geophysical proxy for identifying REY‐rich sediment in marine environments.