FEATURES OF THE SPOROPOLLEN ASSEMBLAGES AT SOUTHWESTERN PEARL RIVER ESTUARY OVER THE PAST 8 000 YEARS AND ITS PALEOCLIMATE IMPLICATIONS

On the basis of spore-pollen assemblage of the core ZJK04 (112°45'19.898″E, 21°46'04.580″N, water depth 7 m, core length 14.6 m) collected in the southwest of Pearl River Estuary, the evolutionary history of vegetation and climatic variation in Pearl River Estuary since 8 000 aBP was reconstructed. The spore-pollen curves made it possible to subdivide the succession into four different time intervals. The climate inferred from the spore-pollen assemblages was warm and wet in the Period I (8 090~7 800 aBP), temperate and wet in the Period Ⅱ (7 800~4200 aBP), cool and dry in the Period Ⅲ (4 200~833 aBP), and relatively cold and wet in the Period IV (after 833 aBP). The most significant change in vegetation and climate in the Pearl River Estuary occurred around 4 200 aBP when it quickly became cool and dry, matching well with 4.2 ka BP event at middle and low latitudes of the Northern Hemisphere. And the sharp increase in content of the Dicranopteris pollen may be related to the human activities at that time.