Climate forcing of turbidite system on the northern South China Sea margin during the Late Quaternary

Turbidites preserved within sedimentary sequences serve as valuable archives of sea-level and climate fluctuations that influence terrigenous sediment supply and depositional processes. However, a comprehensive understanding of how turbidite systems respond to the complex interplay of external forcing on millennial timescales remains limited. Using grain size, geochemical, and chronological data from two sediment cores in different geomorphic settings, we investigate how turbidite system growth responds to sea level, climate and tectonics along the northern South China Sea (SCS) margin. Core QDN-2, located on the northwestern SCS margin, records two turbidites deposited between 43 ka and 12 ka, followed by a cessation of activity during the Holocene. Conversely, core TXN-1 situated on the northeastern SCS margin, documents frequent turbidity currents since 12 ka. These contrasting records demonstrate that turbidite systems on the northern SCS margin can develop at any sea-level. Our findings reveal that while sea level and tectonics play a role, climate emerges as the dominant external forcing on turbidite system development in the northern SCS. Sufficient climate-induced sediment supply compensates for the influence of interception by the wide shelf and high sea level, providing the necessary material basis for the initiation of turbidity currents. The rapid delivery of terrigenous sediments through turbidity currents facilitates the preservation of these climatic signals within the turbidites. This study highlights the crucial role of climate forcing in turbidite depositional patterns, even on the wide continental shelves, and emphasizes the importance of incorporating climate variability into sequence stratigraphic interpretations.