Paleo-environmental change during the late Holocene in the southeastern Yellow Sea, Korea

Abstract

Origin of fine-grained terrigenous sediments and integrative interpretation of their detailed variations in the southeastern Yellow Sea (YS) since the Last Glacial Maximum (LGM) have not been well understood. We investigated the provenance and paleo-environmental changes of the southeastern YS by examining clay mineral changes from borehole HMB-102 and HMB-103. Down-core variations in these clay mineral compositions suggest a distinct change in the provenance of fine-grained sediments of the Heuksan Mud Belt (HMB). Before 13.32ka, sediments were mostly derived from the Korean rivers, from the paleo-Huanghe during between 13.32 to 11.08ka, and from the Korean rivers with minor contributions from the paleo-Huanghe during 11.08 to 6.77ka. After 6.77ka, when the sea level was high and the shoreline was near the Korean Peninsula, materials may come from the Korean rivers. The provenance change after LGM occurred due to an increase in water depth caused by climate change and evolution of Kuroshio Current (KC).