Abrupt Shifts in Holocene Climate and Sea-Level on the Taihu Basin and Cultural Implication

Large magnitude of Neolithic cultural sites in the Taihu Plain provided an exceptional media for the studies of initiation and evolution of human environment interactions. Neolithic cultures in the region were used to be believed as continuous and were categorized into three consecutive stages: (1)Majiabang Cultures (7000-6000 a BP), (2)Songze Cultures (6000-5000 a BP) and (3)Liangzhu Cultures (5000-4000 a BP). However, archaeological excavations in the region substantiated that the cultural layers of many Neolithic culture sites are discontinuous. Moreover, there are number of fossil trees, peat and shell ridges in the region. They could not only serve as the evidence for floods and/or lake expansion, but also enact as the indicator of sea level fluctuation. Evidence for changes in precipitation, sea level and rise and fall of Neolithic cultures from them could offer us a temporal framework by which culture response to climate and sea level oscillations can be assessed. Fossil trees, peat, shell ridges and Neolithic culture sites in the region reveal the temporal connection between Holocene climate and sea level fluctuations and rise and fall of Neolithic cultures. The warming climates and increasing rainfall maintain a period of high sea level that span from 7500a BP to 4000a BP approximately. Meanwhile, the Neolithic cultures develop prosperously conditioned by such optimal environments. However, ice core records show that the Holocene climate is not sustainable stable even in Hypsithermal interval. The cultural interruption, fossil trees, peat and shell ridges in the study demonstrate that there are four fluctuation of the sea level, that is, 7ka-6.5kaBP high level period, 6.3ka-5.6kaBP low level period, 3.8ka-3.5kaBP high level period. On the other hand, the study found that there are at least 9 extreme deluge periods since 7kaBP, i.e., 6.5kaBP, 6kaBP, 5.5kaBP, 5kaBP, 4kaBP, 3kaBP, 2.5kaBP, 3rd-6th centuries and 12th-19th centuries. Since 2kaBP interval periods between adjacent deluges have been reduced obviously, which has a close relation to human activities. The spatial distribution of Neolithic culture sites in the region demonstrates that sea level or coastline is a main influence on civilization migration. The sites during Majiabang Cultures mainly distribute in relatively high land of western Taihu Plain owing to high seal level conditioned by warm and humid climates. The human beings have to migrate towards the west high land for agriculture pursuit because of the limited area for human settlement. The sites during Songze Cultures begin to emanate and expanse. Most of them are situated in the eastern Taihu Plain and the north bank of the Yangtze River. The declined sea level enlarge the area for human settlement, the human beings migrate towards east littoral plain. The sites during Liangzhu Cultures are mainly located in the western Taihu Plain. The area for human settlement in the north bank of Yangtze River is condensed by the increased sea level.