A review on the role of the Mekong River in contributing terrigenous sediments in the southwest East Sea

Abstract

The Mekong River is the largest river surrounding the East Sea and transports much terrigenous sediments to the southwestern East Sea. However, this region still has contained different standpoints on the sediment contribution from the Mekong River. In this study, clay mineralogy and elemental geochemistry of cores MD01-2393, MD97-2150, SO18383-3, 86GC, and KC09 from previous studies are employed to review sediment provenances in the southwestern East Sea and the role of the Mekong River in contributing terrigenous sediments in this region. According to clay mineralogy and elemental geochemistry, provenance analyses indicate that the Mekong River primarily provides terrigenous sediments to the southwestern East Sea, while rivers in Borneo, Malay, Sumatra, and Thailand can supply insignificant amounts of terrigenous sediments to this area. Based on the abundance of fine grain (silt and clay) and foraminifera in sediment cores, terrigenous sediments in the southwestern East Sea cannot be weathering products of parent rocks in the deep-sea basin, implying that these sediments could originate from remote sources. Our study reveals that the Mekong River plays the most crucial role in contributing terrigenous sediments to the southwestern East Sea.