Acta Geographica Sinica ›› 2011, Vol. 66 ›› Issue (1): 123-130.doi: 10.11821/xb201101012

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Last Five Heinrich Events Revealed by Lacustrine Sediments from Xiaozhongdian Basin in Yunnan Province

MING Qingzhong, SU Huai, SHI Zhengtao, DONG Ming, ZHANGWenxiang   

  1. College of Tourism and Geography Sciences, Yunnan Normal University, Kunming 650092, China
  • Received:2010-08-29 Revised:2010-11-12 Online:2011-01-25 Published:2011-01-25
  • Supported by:

    National Natural Science Foundation of China, No.U0933604; No.40872118; Young and Middle-aged Academic Leader Training Foundation of Yunnan Province; 2009 Key Program of Yunnan Science and Technology Development Funds; Key Project of the Ministry of Education of China, No.207102; Science and Technology Planning Project of Yunnan Province, No.2007D199M; No.2010CD043

Abstract: Xiaozhongdian Basin is located in the southeastern margin of the Qinghai-Tibet Plateau which is completely controlled by southwest monsoonal circulation. A thick continental lacustrine sedimentary sequence is preserved due to late Cenozoic fault depression and offers a unique opportunity to study the variability of the southwest monsoonal circulation in detail. Based on the analytical results of grain size, spore-pollen and geochemical elements and 14C datings from a 15.3-m-long lacustrine stratum, five lake dry and shrink events during the last 40 ka, which might be correlated to Heinrich events H0-H4 discovered in North Atlantic region, have been found in Xiaozhongdian Basin, suggesting that Heinrich events for the last 40 ka are strongly imprinted not only in moisture source area of southwest monsoonal circulation, but also in inland area controlled by this circulation. The Heinrich events footprint became drier in inland area, differently from that in moisture source area. However, the signals of the D/O (Dansgaard-Oescher) warm events, which are also clearly recorded in Greenland ice cores and Arabian Sea sediment cores, are ambiguous in Xiaozhongdian Basin. According to the general circulation patterns, we believe that the effect attenuation of the Qinghai-Tibet Plateau on “Pumping Action”of southwest monsoonal circulation system during the glacial periods should be responsible for this phenomenon.

Key words: Xiaozhongdian Basin, southwest monsoonal circulation, Heinrich events