Geochemical Compositions and Transport Patterns of Surface Sediments from the Malacca Strait

The Malacca Strait (MS) is a vital conduit for the exchange of water and sediment between the Indian Ocean and the Pacific Ocean, serving as a critical ‘gateway’ for sediment transport. Here, we present the geochemical characteristics of surface sediments in the MS to elucidate the relationship between terrestrial material inputs and modern oceanic dynamic transport processes in the strait. The results reveal that the MS can be divided into three distinct geochemical provinces. Province I, located in the central region of the strait, is characterized by residual deposits. The preservation of these residual deposits can be attributed to the restricted sediment supply and the relatively weaker modern sedimentary hydrodynamic conditions. Province II, situated to the north of Province I, exhibits provenance differences between its southern and northern regions. The northern region is primarily supplied by sediments originating from the eastern shelf of the Andaman Sea, whereas sediments derived from Sumatra and the Sunda Shelf are predominantly deposited in the southern part of Province II. Province III extends along the western coast of the Malaysian Peninsula, with sediments primarily sourced from the Malaysian Peninsula and the Sunda Shelf, while contributions from Sumatra and the eastern shelf of the Andaman Sea are negligible. River sediments from the Malaysian Peninsula and Sumatra are transported northwestward along their respective coasts by prevailing currents, which also facilitate the transportation of Sunda Shelf sediments within the strait, while sediments from the eastern shelf of the Andaman Sea are delivered to the MS via southward coastal currents during the southwest monsoon period. The southward currents and well-developed eddies potentially impede the northward transport of sediments from the Sunda Shelf and restrict the distribution of Andaman Sea sediments within the strait. This study substantially enhances the understanding of source-to-sink processes in the Indo-Pacific region.