Sequence Stratigraphy of Late Quaternary Deposits in the Southeastern Yellow Sea of Korea

Abstract

High-resolution seismic profiles were analysed to investigate the sequence stratigraphy of late Quaternary deposits in the southeastern Yellow Sea of Korea. Approximately 1500 line-km data of chirp and sparker profiles were acquired. We also used deep drill cores to interpret the sedimentary sequence. High-resolution seismic profiles reveal the Holocene mud deposits and the complex sedimentary structure. The late Quaternary deposits in the study area can be divided into four sedimentary units (units A, B, C, and D from oldest to youngest) bounded by an erosional surface and internal seismic reflector: (1) incised channel fill/lowstand deltaic wedge (unit A); (2) transgressive sand ridges and sand sheets (unit B); (3) estuarine/deltaic or shallow-water mud (unit C); and (4) distal mud patch (unit D). Unit C is divided into two sedimentary subunits on the basis of high amplitude and unconformity: (i) estuarine/deltaic mud (unit C-a); and (ii) mud redeposited by sea-level rise and strong tidal currents (unit C-b). The evolution of units C-a and C-b is closely related to postglacial sea-level changes, sediment erosion, and reworking. These late Quaternary deposits have been controlled by sea-level change, tidal currents, and sediment erosion.