Paper No. 42-7
Presentation Time: 11:05 AM
THE IMPACT OF EXTREME HYDROLOGICAL EVENTS AND SEA-LEVEL CHANGES ON EARLY CIVILIZATION IN ASIAN PACIFIC: A MOLECULAR ISOTOPE ANALYSIS OF SEDIMENTARY RECORDS
The East Asian Monsoon has a profound impact on the development of ancient civilization in coastal areas of Asian Pacific during the Late Quaternary time. However, the way in which extreme hydrological events and major sea-level changes influenced specific civilization in the region remains elusive, primarily due to the lack of detailed climatic records associated with critical cultural periods. Here, we present high-resolution molecular isotope analyses of Late Quaternary non-marine sequential sediments from the Tianloushan archeological site and Poyang Lake in eastern China to infer hydrological changes spanning ~7000 years (~7 ka). Combined with micro-paleontological records, n-alkane carbon (δ13C) and hydrogen (δD) isotope data retrieved from sediments sampled every 5 cm from a 360 cm sedimentary sequence at the Tianluoshan archaeological site in China’s eastern coastal region reveal a detailed climatic change profile between 7.0 and 4.6 ka. Major hydrological changes are coincided with the critical times of early development of rice domestication in the lower Yangtze region. Downcore variations of δD values of long-chain n-alkanes at the Poyang Lake are interpreted as a result of the combined “amount effect” and evapotranspiration during the past ~2 ka, suggesting a wetter “Medieval Warm Period” (MWP) and a relatively dry “Little Ice Age” (LIA) in the region. Our new isotope data suggest that short-duration local marine transgression/regression events combined with extreme regional climatic changes may have played key roles in shaping the development of certain cultures of ancient civilization, such as the rice domestication, in the coastal region of the Asian Pacific.