晚更新世以来北黄海中部沉积物常微量元素的分布及物源识别

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

通过对北黄海中部DLC70-2孔沉积物常微量元素地球化学研究,分析了其常微量元素地球化学特征,并与周边河流进行了对比,揭示了它的物质来源。结果显示,可将DLC70-2孔岩心划分为6层,它们分别反映了末次间冰期（暖期）晚期以来北黄海海面波动以及沉积物物源的变化。运用因子分析、Na2O/TiO2与K2O/TiO2散点图等方法分析了DLC70-2孔沉积物的物质来源,结果表明该孔沉积物主要来源于黄河,鸭绿江物质对该孔中部及底部沉积物有较明显影响;物源判别指数（PI）揭示DLC70-2孔上部32.10m以上和下部37.60~60.72m沉积物以黄河源为主,32.10~37.60m和底部60.72~70.45m沉积物以鸭绿江源为主。研究表明黄河从晚更新世早期到现代对北黄海中部沉积起着重要作用,而鸭绿江物质在晚更新世早期开始对北黄海中部沉积作用就有明显影响。

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 Na20/TiO2 vs. K20/TiO2 was drawn to reveal the source of sediments. The results suggest that the sediments of the core mainly come from the Yellow Riv er, 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 be- tween 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 mak- ing contribution to the central North Yellow Sea at the early stage of Late Pleistocene.