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4000aB.P.前后降温事件与中华文明的诞生
引用本文:吴文祥, 刘东生. 4000aB.P.前后降温事件与中华文明的诞生[J]. 第四纪研究, 2001, 21(5): 443-451.
作者姓名:吴文祥  刘东生
作者单位:中国科学院地质与地球物理研究所, 北京 100029
基金项目:国家自然科学基金 (批准号 :4 9894 1 70 )资助重大项目
摘    要:4000aB .P .前后降温事件是世界上许多地区全新世人类演化史上的重要转折点之一 ,也是导致古埃及、两河流域和印度河流域等地区世界古文明衰落的主要原因。在中国 ,该降温事件导致了中原周围地区五大新石器文化的衰落和终结 ,但却加速和促进了中原地区以夏朝建立为标志的中华文明的诞生.

关 键 词:降温事件   中华文明
收稿时间:2001-06-30
修稿时间:2001-06-30

4 000aB. P. EVENT AND ITS IMPLICATIONS FOR THE ORIGIN OF ANCIENT CHINESE CIVILIZATION
Wu Wenxiang, Liu Tungsheng. 4000aB.P. EVENT AND ITS IMPLICATIONS FOR THE ORIGIN OF ANCIENT CHINESE CIVILIZATION[J]. Quaternary Sciences, 2001, 21(5): 443-451.
Authors:Wu Wenxiang Liu Tungsheng
Affiliation:Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029
Abstract:Carbon isotopic composition of pedogenic carbonate can be used as an indicator of paleoenvironmental change. Carbon isotopes yield paleoenvironmental information because carbon in soil carbonate forms in isotopic equilibrium with local soil CO 2, whose δ 13 C is determined by local plant cover. Plants can be grouped into two major groups which have different isotop ic values. The C 3 and C 4 plants use different photosynthetic pathways and have very different δ 13 C values averaging about -27‰ and -13‰, respectively. C 3 plants include nearly all trees, most shrubs, and cool season grasses. C 4 plants include some shrubs and warm season grasses. In this paper, carbon isotopic composition of soil carbonate in Weinan, Jixian, Changwu and Huining during last interglacial (S 1) and last glacial (L 1) was analyzed to examine the main factor for the variations of δ 13 C values of soil carbonate formed in different climatic conditions and its implications on paleoenvironmental reconstruction in the red earth sequence at Xifeng.;Results from four different sites have shown that S 1 is characterized by more negative δ 13 C values of carbonate while L 1 by more positive δ 13 C values, implying that C 3 plants dominated on the Loess Plateau during last interglacial (S 1), and C 4 plants favored the climatic condition during last glacial (L 1). The humidity is most likely the main factor influencing δ 13 C values of soil carbonate in the Loess Plateau.;Carbon isotopic composition of pedogenic carbonate was analyzed on paleosols of a red earth sequence at Xifeng. An increase in δ 13 C values occurs around 4.0 Ma B.P., implying increase of C 4 plants biomass. The fact that this C 4 vegetation event occurred simultaneously in the Loess Plateau, but different from the C 4 expansion in Pakistan and other localities in terms of timing and nature, may suggest that local climatic changes were main factors for driving the expansion of C 4 vegetation. We argued that the Pliocene expansion of C 4 plants in northern China might have been caused by increased aridity, which in turn might be related to the uplift of Tibetan Plateau.
Keywords:cold event   ancient Chinese civilization
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