Concordant monsoon-driven postglacial hydrological changes in peat and stalagmite records and their impacts on prehistoric cultures in central China
Shucheng Xie et al., State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China. First published on 28 June 2013, http://dx.doi.org/10.1130/G34318.1.
Drought and flooding exert important impacts on anthropogenic activities in modern days or in ancient times. However, in comparison with the paleo-temperature, we know much less about the variation of hydrological conditions in ancient times. This is primarily due to the difficulty in the reconstruction of rainfall amount, resulting from the restricted proxies. Two new independent proxy records from peatland and stalagmite archives were proposed to trace monsoon-driven hydrological changes occurring since the last deglaciation in a broad region of middle Yangtze area of China. The wet periods are recorded by reduced mass accumulation rates of hopanoids, biomarkers for aerobic microbes in Dajiuhu peatland. The hopanoid-based reconstruction is supported by the first report of the environmental magnetism parameter, the ratio of fine magnetic particles to total ferromagnetic particles in a stalagmite from Heshang cave in central China. Spatiotemporal distributions of over 1600 prehistoric settlement sites of six distinctive cultures of the Neolithic to Iron Ages were observed to correlate with the fluctuating hydrological conditions referred by the two proxies, with enhanced flooding risk forcing major relocations of human settlements away from riparian zones. F
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