Spatial heterogeneity of sedimentary pattern and carbon burial in the Indo-Asia Monsoon Area

The sedimentary systems of marginal seas are among the most intricate globally, posing significant challenges in the depositional pattern. Previous research has indicated that the sedimentary patterns vary across different types of marginal seas, and their relationship with carbon burial remains poorly understood. In this study, we present high-resolution rock magnetic data from Core YDY09 in the Bay of Bengal, offering a detailed record of terrigenous sedimentation spanning nearly 50,000 years. Our data show that magnetic susceptibility increased significantly during the Last Glacial Maximum (LGM, 26,000-19,000 years ago), reflecting a sharp rise in terrigenous sediment flux. However, this increase diluted marine productivity, consequently reducing overall carbon burial. Comparisons with other marginal seas reveal that sedimentation processes in the Bay of Bengal are particularly shaped by the topography of the Himalayan Plateau, forming a distinctive "Plateau-canyon channel" model. This model is crucial for understanding carbon cycle studies in marginal seas and sheds light on the region’s unique sedimentary dynamics.