Microfossil assemblage characteristics in Core B_(10) and implication for paleoenvironmental evolution in the southern Yellow Sea

摘要

Microfossil assemblage and pollen zone characteristics in Core B_(10) recorded the history of environmental changes in the southern Yellow Sea since Wurm Subinterglaciation. Environmental variations reflected by these glacial and interglacial sediments coincide with general characteristics of paleoenvironmental and sedimentary changes in the Yellow Sea. In the section of 550-520 cm, microfossil foraminifera have low abundance and diversity, and pollens are composed mainly of those of herbaceous vegetation, indicating climate change during Wurm Subinterglaciation. In the section of 520-140 cm, the changes from a few microfossils to no microfossils reflect the sedimentary environment variation from coastal to terrestrial facies. Paleoclimate reflected by pollen also underwent the changes from conifer-broadleaf mixed forest to grassland, indicating the climate changes from temperate and cool type to warm and dry one. In the section of 140-0 cm, the general microfossil characteristics are the gradual increase in aundance with most species being neritic species, the major pllen being ligneous pollen and the rapid increase in small Hystrichosphaera content, which indicates that the air temperature increased and the sevel gradually rose.