Abstract

Two piston-core sediments, obtained from the southwestern margin of the Ulleung Basin in East Sea, are analyzed to investigate the stratigraphy and sedimentary environment of the Late Quaternary. The cores consist mainly of muddy sediments with silty sands, lapilli tephra and ash layers. The chronostratigraphic correlation with known eruption ages reveals that the core sediments contain the stratigraphic document over the past 46.1 kyr and the sedimentation rates during the last glacial period were relatively higher (12.1~14.9 cm/kyr) than those in pelagic ocean. Several sedimentary facies, mainly affected by turbidity currents, are commonly present in the core interval accumulated during the oxygen-isotope stage 2. Many of horizontal voids, which are thought to have formed by gas
expansion, are observed in core 00GHP-07. The total organic carbon (TOC) contents of the core sediments are noticeably high (average 1.8%). Particularly, these TOC values increased during Termination I, suggesting that during this time interval the sedimentary environment of the study area was changed to more anoxic.

Keywords Late quaternary, sedimentary environment, muddy sediments, tephra layer, total organic carbon, Ulleung Basin