Geochemical composition and provenance discrimination of coastal sediments around Cheju Island in the southeastern Yellow Sea

Sediments from the northern coastal area of Cheju Island (South Sea of Korea, southeastern Yellow Sea) were analyzed for grain size composition, elemental compositions and clay mineralogy in order to investigate their provenance. Rare earth element (REE) compositions and geochemical discrimination diagrams were revealed to be useful indices for identifying the origin of sediments in the study area. These indices, together with clay mineral compositions, suggest that both the sandy and muddy sediments originated from weathering of the volcanic rocks of Cheju Island, whereas sediments originating from the Changjiang and Huanghe rivers cannot be traced in the study area. Similarly, river-borne matter from the Korea Peninsula has little influence on the sediment deposited. Therefore, the suggestion that fine-grained Changjiang sediments can reach the nearshore area of Cheju Island (the Cheju strait) suggested by oceanic circulation patterns in the Yellow and East China Seas cannot be supported by this study based on geochemical and mineralogical analyses.