Source Indication of Rare Earth Elements in Surface Sediments of Rizhao Offshore

Based on the particle size and REE analysis of 50 surface sediment samples from offshore seabed and 21 surface sediment samples from the surrounding rivers were tested and analyzed. The REE compositions were compared with those from coastal rivers, beach throughs and Yellow River sediments. Using the <italic>F</italic>_D discriminant function and stable elements (Al, Ti, Zr, and Nb), a comprehensive study was conducted to investigate the distribution characteristics, Eu and Ce anomalized partition curves, and material sources of surface sediments in the Rizhao coastal waters. The results show that the content of rare earth elements in the surface sediments of the study area ranges from 110.31 μg/g to 205.37 μg/g, the light rare earth element (LREE) content are enriched, with a LREE/HREE ratio ranging from 8.7 to 11.0. There is a moderate negative europium (Eu) anomaly, and no significant cerium (Ce) anomaly is observed. The discriminant function (<italic>F</italic>_D ) value is less than 0.2, suggesting that the primary source of the surface sediments in the study area is the interaction of Yellow River material, beach erosion material, and surrounding river material entering the sea.