Environment Change And Civilization Response During The Early Holocene In Zhejiang Province

Holocene is the most closely period related to human beings. It recorded the process of development of human civilization. During this period, the ancient civilization developed unprecedented in the world.However, with the lowly society productivity, human's production and living depended on natural environment heavily in the early Holocene. Climate change is the most important factor to the nurtured, prosperity and decline of the early human civilization. Zhejiang province' climate is subtropical monsoon. There is dense river network, lush vegetation. Sea-level fluctuations affect the nature factors of Zhejiang province and it is a sensitive area responded to global climate changes. There are many Neolithic archaeological remains of early Holocene in Zhejiang province and they had made important contributions for the birth and development of Chinese civilization. So far, there are Shangshan cultures, Xiaohuangshan cultures and Kuahuqiao cultures flourished in Zhejiang province and their birth, development, decline were in the context of global environment change. There are four types of sediment of Holocene in Zhejiang province, marine type, alluvial-marine type, alluvial and flood type and lake type. The Holocene deposits concentrated in the flat plains and valley basins in Zhejiang province and the most widely distributed in Hangjiahu Plain and Ningshao Plain. Continental deposits was the mainly deposition of early Holocene. Due to the increasing influence of sea-level, the continental sedimentary transited to the marine sediments along the coastal areas. The alluvial-marine sediment types gradually formed at estuary region. Some plain with rivers and lakes gradually transformed into low-salt marsh and the limnology sediment formed. Alluvial sediments and alluvial sediments type formed due to the weak erosion and incision of river and they were the mainly sediments in the inland area.Most cultural sites of the early Holocene were along the Puyang River and Cao'e River. According to the sedimentary characteristics of following drilling (18.3-8.8m) of Beihuqiao (short title BHQ, total length of 18.8m) which at the junction of north Zhejiang Hangjiahu Plain and western Zhejiang hills, the limnology sediment is the mainly sediment type in the early Holocene. Basis on the analysis of grain size and geochemical, combined with pollen research by the previous studies around neighboring areas, the early Holocene can divided into three paragraph:(1) Increasingly warm and wet climate in early HoloceneAt 18.35～17.0m of BHQ drilling, the sediments with thin size, concentrated particle size, poor sorting and approximate symmetrical skewness in this paragraph. With high contents of K2O,Fe2O3,Cu,V and Rb and the low contents of Na2O,CaO and Sr, this paragraph had more clay mineral, enough water and dense vegetation. High-value of CIA curve and Rb/Sr and low-value of SiO2/Al2O3 showed warm and humid climatic conditions and strong weathering of this paragraph.(2) Cold and dry environment evemt in early HoloceneAt 17.0～13.0m of BHQ drilling, about 17m each index had a sudden change with thick size, worse sorting and great change of skewness, the sedimentary environment is unstable. After swoop, the consents of K2O,Fe2O3,Cu,V and Rb is lower and the consents of Na2O,CaO and Sr is higher. Low-value of CIA curve and Rb/Sr and high-value of SiO2/Al2O3 showed cool and dry climate conditions and weak weathering of this paragraph. There was a warm and wet climate warm at about 15m of BHQ drilling with thinner size and strong weathering.(3) The gradually warmer environment after cold eventAt 13.0～8.75m of BHQ drilling, in this paragraph, there is dark gray peat with micro-bedding and the grain size is thinner, the sorting is stronger than the second paragraph. The contents of K2O, Fe2O3, Cu, V and Rb were increasing and Na2O, CaO and Sr were reducing, reflecting the climatic conditions gradually shifted to warm and humid. The rate of change was rapid at 13.0～11.0m showed that warming climate change rate from rapid to slow after cold event.The Holocene ancient civilization's born, development and decline was closely related to environmental change in Zhejiang province. Climate and environment evolution and the evolution of human culture had a good coupling, suitable climate provided favorable conditions for the survival of ancient civilization, and severe climate events will interrupt the development of civilization, while the adaptability of human beings strengthen to the climate change. In the early Holocene, the gradual warming climate made the Mid-Zhejiang valley basin areas is suitable for human survival and development, promoting the Shangshan culture which around Puyang River basin and Xiaohuangshan culture which around the Cao'e River basin to developing. The ancestors'way of lives depended on capture and primitive rice farming appeared. With the early Holocene cooling events, ancestors could not hunting and gathering and rice cultivation in the basin of Puyang River upstream and the residents were forced to migrated to downstream. After the cooling event the climate was more warm and humid, Puyang River Estuary's natural conditions was superior, promoting the ancestors continued to migration in, with the marine nature of the kuahuqiao civilization flourished. The production activities of ancestors including fishing, hunting, gathering, and began to grow rice, pottery and other technology aspects had a lot of progress. With the gradually warming climate, rising sea levels threatened the ecological environment of kuahuqiao culture and restricted the development of kuahuqiao civilization.