Abstract:
Detrital zircons taken from four surface sediments and five sediment samples from SYS90-1A borehole in the southern part of the central mud area of the South Yellow Sea was U-Pb dated and their provenances were discriminated, based on which the changes since about 1.0 Ma in the provenance of the sediment samples were analyzed. Results show that the sediments in the mud area are mainly from the Yellow River, and the sediments in the south of the mud area may be transported by the Yangtze River. The borehole SYS90-1A mainly records the deposits since the late Early Pleistocene, showing obvious provenance differences in different stages. In the early Middle Pleistocene, the sediments were mainly transported from the Yangtze River; and cyclic stratigraphy that was determined based on magnetic susceptibility and astronomical chronology tuning showed that the specific time of the stage is 590~710 ka. From the late early Pleistocene to the middle Pleistocene and since the middle Pleistocene, the sediments were mainly from the Yellow River. This result is different from the previous understanding that the sediments in the South Yellow Sea since the Early Pleistocene were mainly derived from the Yellow River, and the contribution of the sediments from the Yangtze River to the mud area needs to be re-recognized. The detrital zircon U-Pb age distribution of all samples is completely different from that of the fluvial sediments of the Korean Peninsula, indicating that the sediments in this area are mainly from mainland China since the late Early Pleistocene.