Deep-sea sediments enriched in rare earth elements and yttrium (REY) are potential strategic resources, with iron-bearing minerals serving as crucial REY carriers. Clay-sized fractions (<2 mu m), accounting for similar to 60-90 % of bulk sediments, have a unique mineralogical composition that enables effective sequential chemical extraction. Previous studies have revealed distinct REY patterns in sequentially leached iron pools, yet the provenance of these iron pools and the redox-driven Fe-REY cycling processes remain poorly constrained. In this study, we conducted sequential Fe extractions and iron isotopic (delta Fe-56) analyses on clay-sized fractions from two deep-sea sediment cores (P30 and P64) in the western Pacific. The acetate-leached Fe phase (Fe-aca; delta Fe-56 = 0.25 parts per thousand-0.41 parts per thousand) exhibits very low Zr/Ti ratios and a seawater-like delta Fe-56 signature (similar to+0.4 parts per thousand, the long-term average delta Fe-56 of the deep Pacific over the past 20 Myr), implicating that nanocrystalline Fe (oxyhydr)oxide colloids scavenge abundant REY from seawater. The amorphous Fe phase (Fe-ox1) shows seawater-like (La/Yb)(N) ratios, low Zr/Ti ratios, the highest Sigma REY contents, and the lightest delta Fe-56 signatures (delta Fe-56 = -1.03 parts per thousand to -0.50 parts per thousand), indicating that authigenic Fe (oxyhydr)oxide precipitation constitutes a primary REY sink in clay-sized sediments. In contrast, the crystalline Fe (Fe-ox2), phyllosilicate-bound Fe (Fe-HCl), and residual Fe (Fe-R) phases exhibit increasingly higher delta Fe-56 values (0.05 parts per thousand-0.55 parts per thousand) and cerium anomaly (delta Ce) values similar to those of East Asian desert dust. These signatures are indicative of their dominant aeolian source, with the retention of Fe-56 in these phases during continental weathering. These findings underscore mineral-specific Fe-REY coupling among diverse Fe sources in marine sediments-a key role in marine REY enrichment mechanisms.