Deciphering Depositional Processes of Continental Shelf Strata in the Northeastern East China Sea

Abstract

This study concentrates on the depositional processes of continental shelf strata in the northeastern limit area of the East China Sea. The study area is located between the East China Sea and the Yellow Sea of the epicontinental sea where experienced the dramatic sea-level changes during the Quaternary. The area is a low-gradient continental shelf in a water depth of ~100 m around 32°30 to 35N, 126°05 to 12E, about 70 km southwest of Cheju Island. It might be completely exposed during the last glacial maximum (LGM). In the study area, the pre-LGM strata comprises incised channel fills and prograding deposits of fluvial, estuarine, or tidal origin. The postglacial transgression of the sea-level changes formed the paralic deposition of estuarine channel fills, prograding wedge and mound, marine sand veneer, and mud blanket. This study will reveal the depositional processes of the continental shelf strata, based on closely spaced high-resolution seismic profiles (Chirp and Sparker) with piston/grab/box cores. The detailed seismic survey (~110 line-km of 8 lines) and coring work including 36 piston cores were fulfilled in the relatively small marine area (15 x 10 km2 in area) for deciphering the depositional processes of different physical, sedimentological, and geoacoustic properties in the northeastern East China Sea.experienced the dramatic sea-level changes during the Quaternary. The area is a low-gradient continental shelf in a water depth of ~100 m around 32°30 to 35N, 126°05 to 12E, about 70 km southwest of Cheju Island. It might be completely exposed during the last glacial maximum (LGM). In the study area, the pre-LGM strata comprises incised channel fills and prograding deposits of fluvial, estuarine, or tidal origin. The postglacial transgression of the sea-level changes formed the paralic deposition of estuarine channel fills, prograding wedge and mound, marine sand veneer, and mud blanket. This study will reveal the depositional processes of the continental shelf strata, based on closely spaced high-resolution seismic profiles (Chirp and Sparker) with piston/grab/box cores. The detailed seismic survey (~110 line-km of 8 lines) and coring work including 36 piston cores were fulfilled in the relatively small marine area (15 x 10 km2 in area) for deciphering the depositional processes of different physical, sedimentological, and geoacoustic properties in the northeastern East China Sea.