Abstract:

The sediment samples derived from drillhole DLC70-3(71.20 meters in depth) in the northern South Yellow Sea were measured for analysis of element geochemistry and their provenances were discriminated with the purpose of studying the indicator significance of element geochemistry information for the stratigraphic division and provenance analysis of mud area in northern South Yellow Sea. According to the changing law of element contents and their ratios，the sediments from drillhole DLC70-3 can be divided into five layers, reflecting the fluctuation of sea level and the change of sediment sources in northern South Yellow Sea since the late of the last interglacial cycle (warm period). Combined with discriminate function，the scatter diagrams of MgO/Na2O vs. CIA were drawn to determine the material source of sediments from drillhole DLC70-3. The results revealed that the material sources of sediments mainly came from the Yellow River，and sediments in the upper-middle and in the lower of the drillhole were apparently influenced by materials from the Changjiang River. The sediments above the depth of 4.50 m in the upper and between 27.80 m and 38.80 m in the middle of drillhole DLC70-3 mainly belong to the Yellow River source; the sediments from 4.50 m to 27.80 m in the upper-middle，from 38.80 m to 55.00 m in the lower and from 55.00 m to 71.20 m at the bottom were mainly derived from the Changjiang River. It is concluded that the Yellow River is playing an important role in northern South Yellow Sea at the middle stage of Late Pleistocene and the Changjiang River has started to obviously influence northern South Yellow Sea since early Late Pleistocene.

Key words: sediment, Late Pleistocene, source analysis, northern South Yellow Sea