A. Prof. Jing Fang
Tianjin Normal University, China
High stand sea level in Holocene, inferred from buried peat and diatom assemblages from northern coast of North Yellow Sea
Understanding the paleo sea-level change is of significance for better coastal protection and prediction of sea-level rise in the future. Information of sea-level change has been documented in various archives in the coastal area. In this study, the well-preserved peat in three representative Holocene ditches in Dayanghe plain in North Yellow Sea China were investigated in aspects of chronology, diatom analysis and which has significant instruction for present sea level change and coastal environmental process, we investigate in onshore area near modern coast line of North Yellow Sea. Diatom analysis and 14C dating method are employed here to identify the types of peat in different depth and confirm the timing of high stand sea level. The results show that the widely distributed buried peat in Dayanghe plain was classified as marsh and limnological peat, which formed after sea water quitting from drowned ditches in height of approximately 2-10 m a.s.l. Only peat under 4 m a.s.l., contacting with lower marine section conformable, were associated with the process of regression by diatom analysis. The approximately 4 m a.s.l. high peatlands formed in period of 6 182 ~ 5 466 cal a BP, constrained to the high sea level, which was 1.60 m higher than present. Based on integrated explanation of diatom analysis, radiocarbon dates, shell banks at west of Dagu Mountain which was in 7 ~ 10 m high were not constrained to high sea level. Observation data of height measurement also suggested that shell banks could not be treated to indicator of high sea level.