CHANGES OF QUATERNARY PALEOCLIMATES IN THE PLAIN AREA OF BEIJING

According to the stratigraphic classification based on the cores from well HR_88-01 of Huirou, the paper systematically deals with the changes of the fossil assemblage types of sporopollen, ostracods and mollusks and assemblages of heavy minerals, clay minerals and some geochemical elements and analyzes the paleoclimate types represented by them. The following speculations have been made: （1） in the Pliocene the climate was wet and hot with temperatures 4～5℃ higher than the present ones; （2） in the Early Pleistocene the climate became obviously cold, which was manifested by a warm season sandwiched between two cold seasons, with the temperatures of the cold season 7～8℃ lower than the present ones; （3） in the Middle Pleistocene the temperatures fluctuated, manifested by warm-coldwarm-cold, with the temperatures of the cold season 6℃ or so lower than the present ones and those of the warm season about 1～2℃ higher than the present ones; （4）in the Late Pleistocene, the climate was dry and cold, with the temperatures about 5℃ lower than the present ones.