Sediment provenance identification and paleoenvironmental characteristics since MIS5 in the western shelf area of the South Yellow Sea

摘要

The sediment provenance identification and paleoenvironmental characteristics in the western shelf area of the South Yellow Sea, are of great significance to study the environmental evolution of the Chinese Shelf Sea since the Last Glacial period and to solve the environmental geological problems in the exploitation of the shelf. In this paper, the UCC-normalized rare earth element (REE) distribution patterns, the provenance index of sediments (PI) and the correlation between 5Eu and EREE are used to analyze the sediment provenance since MIS5 in the western shelf area of the South Yellow Sea. Based on the analysis of mineral assemblages, sediment grain size, foraminifera and sporopollen of core NT1 and NT2, and combined with the distribution characteristics ofpaleochannel, the paleoenvironmentai characteristics in the western shelf area in the South Yellow Sea during the marine isotope stage MIS4 and MIS2 are further studied. The results show that, in the core NT1, sediment provenances of MIS2 and MIS4 in Core NT1 mainly sourced from the Yellow River and the main sediment provenances of MISI, MIS3 and MIS5 from the Yangtze River. In core NT2, the main sediment provenance of MIS3 period was from the Yellow River, and the main sediment provenances of MISI, MIS2, MIS4 and MIS5 sourced from the Yangtze River. All the results incdicicated that the western shelf area of the South Yellow Sea was in a cold and low-sea-level sedimentary environment during MIS4 and MIS2, and the main vegetation types were grassland, coniferous forest and conifer-broadleaf forest.