Provenance of sediments in the Zhongnan Seamount, South China Sea since MIS 3: Insights from clay minerals and geochemical signatures

Abstract

As the widespread and prominent features of the ocean, seamounts are served as natural repositories for sediments, creating a special environment for understanding the sediments from terrigenous source to oceanic sink. However, opportunities to delve into the provenance and sedimentary processes of seamounts has been notably restricted. Here we examine the geochemistry and clay minerals of sediments from the Zhongnan Seamount in the South China Sea, with aims to reveal the provenance of sediments and investigate the transport pathways during the glacial-interglacial periods. Geochemical results indicate that the parent rocks of the sediments vary from andesite and felsic volcanic rocks, which were formed under tectonic settings similar to the continental island arc, suggesting a predominantly terrigenous source. Provenance results indicate that the sediments of the seamount were primarily derived from the islands of Taiwan Island, Luzon, and the Red River, with the sources of sediments varied during glacial-interglacial periods. Since MIS 3, shifts in the provenance of seamount sediments have been associated with variations in sea level prompted by climate change and the transport dynamics of ocean currents. This study proposes the potential of sediments in seamounts to record the hydrodynamic patterns and reveal transport pathways in the source-to-sink systems.