Delta Formation in the Nakdong River, Korea, during the Holocene as Inferred from the Diatom Assemblage

Abstract

ABSTRACT Cho, A.; Cheong, D.; Kim, J.C.; Shin, S.; Park, Y.-H., and Katsuki, K., 2017. Delta formation in the Nakdong River, Korea, during the Holocene as inferred from the diatom assemblage. The causes and succession of the Nakdong River delta formation related to sea-level change and precipitation in the early–middle Holocene were discussed based on diatom analysis. On the basis of ecology, stratigraphic changes of diatom flora were divided into five divisions, labeled zones I–V. According to the diatom assemblage, the first marine transgression occurred at about 10.5 ka at this research site. At that time, marine species gradually increased, and freshwater species had their highest values. This site was an estuary influenced by inputs of fresh and marine water until 9.8 ka (zone I). Zone II is dominated by bay and offshore species, meaning that sea level rose continuously after about 9.8 ka (zone II) when the Nakdong River mouth region was an inner bay. Then, the environment of this site changed to an ...