Role of climate in the rise and fall of Neolithic cultures on the Yangtze Delta

Climatic changes in the Yangtze Delta have played an important role in the emergence, persistence and collapse of civilization. Archaeological excavat ions in the region over many years have demonstrated that there are several layers of fine sand or organic mud that interrupt the consecutive culture strata in a number of Neolithic culture sites. Continuous biostratigraphica l and sedimentological records from the Maqiao cultural site, Shanghai, sug gest that the fine sand and organic mud units resulted from expansion of wa ter bodies both by sea-level fluctuations and from increased flooding durin g cold and humid episodes of Holocene climates. The absence of human settle ment from 7240 BP to 5320 BP in the region was mainly caused by higher sea levels resulting from a warm and humid climate. The Neolithic cultures deve loped under conditions of lower and more stable sea level as well as warmer and dryer climates between about 4410 BP and 3250 BP. A flood-induced lake expansion interrupted the civilization in the region at about 4200 BP. Lat er, higher water tables and expansion of lakes between 3250 BP and AD 618 u nder a cold and moist climate temporarily terminated settlement on the delt a. Later, during the Tang Dynasty, beginning at about AD 618, the region ag ain became suitable for human settlement under conditions of more favourabl e climate and lower water tables.