Evidence for the offshore transport of terrestrial organic matter due to the rise of sea level: The case of the East China Sea continental shelf

Abstract

Accelerator mass spectrometry (AMS) 14C dating and analyses of the stable isotope ratio of organic carbon (δ13Corg) were carried out on two piston cores obtained from the continental slope and the Okinawa Trough in the East China Sea (ECS). These cores covered the last ca. 15 14C kyr BP (17 to 18 cal kyr BP). Mass and organic carbon (org. C) accumulation rates decreased gradually after the last deglaciation period. On the other hand, δ13Corg showed distinct depletion from ca. 14 to 12 14C kyr BP (17.5 to 13.2 cal kyr BP). The depletion relates to the large supply of terrestrial org. C from the ECS shelf triggered by the sea's intrusion onto the shelf area because of the rise in sea level.