Sources, transport and deposition of surface sediments from the South China Sea

Sediment sources, transport and deposition in the South China Sea (SCS) are addressed based on multiple proxies of 111 surface sediment samples, including clay minerals and rare earth elements. Results reveal that sediment sources in the SCS generally contain volcanic, biogenic and terrigenous materials. Volcanic material is typically distributed west of Luzon Island (including adjacent to Huangyan Island). Carbonate biogenic materials (e.g., coral and foraminifera) develop strongly around the Nansha and Xisha Islands. Terrigenous materials mainly derive from the continent via large rivers (e.g., the Pearl, Red and Mekong Rivers) and from islands via mountainous rivers (e.g. the Gaoping River in Southwest Taiwan and Rajang River in northern Kalimantan). According to clay mineral distributions of surface sediments from the SCS, the sediment transport route is traced. It extends to the central basin and even connects with the Sulu Sea through the Mindoro Strait. Further, based on rare earth element (REE) distribution patterns of the fine-grained fraction and clay mineral assemblage of surface sediments, contributions of various sediment sources are estimated at various locations on the SCS slope. ► Compositions of surface sediments from the South China Sea are measured. ► Clay minerals and rare earth elements are analyzed. ► Sediment sources are traced based on mineralogic and geochemical evidences. ► Sediment transport route is explored with clay minerals. ► Contribution of various sources are estimated in different locations of the SCS slope.