VARIATIONS IN EAST ASIA MONSOON AROUND 4 000aB.P. AND THE COLLAPSE OF NEOLITHIC CULTURES AROUND CENTRAL PLAIN
4000aB.P.前后东亚季风变迁与中原周围地区新石器文化的衰落

Significant archaeological transformations that mark the collapse of Neolithic cultures around Central China during the late third millennium B.C. has been recognized widely. However,the causes for their collapse have been in dispute. In this paper,paleoclimatic data are synthesized to show that an interval of sever climatic anomaly occurred around 4 000 aB.P. across much of China,which was synchronous with a climatic event identified at least in northern hemisphere scale. Our syntheses also indicate that this climatic interval not only is one of the several climatic events during the Holocene but also marks the Middle Holocene climatic transition (the ending of Holocene optimum). Based on geological evidences and analysis of relationship between variations in intensity of East Asian Monsoon and the changes in distributional pattern of monsoon-related rain belts in eastern China,it is concluded that this climatic anomaly superimposed on the Middle Holocene transition induced by variation in the Earth's orbit and significantly altered the hydrological regime to generate a sharp contrasted environmental framework of drought in the north and flooding in the south of China,which is mainly responsible for the collapse of Neolithic cultures around Central Plain.