DISTRIBUTION PATTERN AND SOURCE OF MAJOR AND TRACE ELEMENTS IN THE CENTRAL NORTH YELLOW SEA SINCE LATE PLEISTOCENE

The core DLC70-2 was taken from the central North Yellow Sea. Samples were analyzed for major and trace elements and grain size parameters. The purposes of this paper are to study the distribution patterns of major and trace elements in the core sediments; to make the comparison of the major and trace elements compositions between the sediments from the Yalu River estuary and the Yellow river;and to study their implications for the provenance of sediments in the study area. The sediments from the core CLC70-2, which is 70.60 m in depth, can be divided into six layers,upon the fluctuation of sea level and the change in sediment sources in the North Yellow Sea since the late last interglacial cycle (warm period). Combined with factor analysis,the scatter diagram of Na₂O/TiO₂ vs. K₂O/TiO₂ was drawn to reveal the source of sediments. The results suggest that the sediments of the core mainly come from the Yellow River,but the sediments in the middle and bottom parts of the core were apparently influenced by the materials from the Yalu River. The sediments above the depth of 32.10 m in the upper part and between 37.60 and 60.72 m in the lower part of the core are mainly coming from the Yellow River source; the sediments between 32.10~37.60 m in middle and between 60.72 and 70.45 m at the bottom of core DLC70-2 were mainly derived from the Yalu River. It is concluded that the Yellow River has been the major contributor of sediments to the central North Yellow Sea since early Late Pleistocene and the Yalu River started making contribution to the central North Yellow Sea at the early stage of Late Pleistocene.