Late Quaternary sediments and paleoenvironmental evolution on the northern bank of the Qiantang River

Abstract：Based on a comprehensive analysis of lithostratigraphy, chronostratigraphy, spore-pollen zones and foraminiferal assemblages of the Quaternary bore core from the northern bank of the Qiantang River, the author holds that the Holocene sedimentation began from the depth of 35.7 m (about 10.4 ka B.P.), and the strata from this level to the depth of 71.1 m should belong to Late Pleistocene. The author also divides the paleoenvironmental evolution of this hole since 31.2 ka B.P. into five development stages, with a systematic description made in such aspects as paleovegetation, paleoclimate and paleogeography of each stage. It is pointed out that the second stage (20.1～10.4 ka B.P.) was within the low sea level period, during which the climate was cool, cold and dry, that the early period of the second stage may correspond to the glacial maximum of last glaciation, and that the fourth stage (7.5～2.5 ka B.P.) was within the high sea level period, when the climate was warm, hot and damp, corresponding to the Holocene climate optimum that was in line with the global change. The climate change of the last 30,000 years since Late Quaternary in this area exhibits a good comparability with that of the Shenzhen Bay area in southern China.