Long-term trend and abrupt events of the Holocene Asian monsoon inferred from a stalagmiteδ^(18)O record from Shennongjia in Central China  

作　　者：SHAO Xiaohua WANG Yongjin CHENG Hai KONG Xinggong WU Jiangying EDWARDS R. Lawrence 

机构地区：[1]College of Geography Science, Nanjing Normal University, Nanjing 210097, China [2]Department of Geology and Geophysics, Minnesota University, MN 55455, USA

出　　处：《Chinese Science Bulletin》2006年第2期221-228,共8页

基　　金：This work was supported by National Science Foundation of China(Grant No.40225007);The Foundation for the Author of National Excellent Doctoral Dissertation of P.R.China(Grant No.200227).

摘　　要：A high-resolution oxygen-isotope record from a thorium-uranium-dated stalagmite from Shanbao Cave at Shennongjia reflects variations in the amount of monsoon precipitation for the period from 11.5 to 2.1 ka (1 ka = 1000 cal aBP). Between 11.5 and 9.3 ka, a sharp decrease in δ18O indicates a rapid increase in monsoon precipitation. An interval of generally high monsoon precipitation is observed between 9.3 and 4.4 ka. An arid period has prevailed between 4.4 and 2.1 ka. The long-term trend of Shanbao record appears to follow summer insolation at 33°N latitude. An abrupt decrease in monsoon precipitation around 4.3 ka is synchronous with the collapse of Neolithic culture in central China. This abrupt change could have resulted from the amplifi- cation of the gradually decreased summer insolation by the positive vegetation-atmosphere-aerosol feed- back. The weakened Asian monsoon events were in concert with decreased Greenland temperature dur- ing the early Holocene, centered at 8.2, 8.6, 9.3, 10.2 and 11.0 ka. This correlation suggests that changes in low-latitude monsoon are connected with climate change in high-latitude polar region.A high-resolution oxygen-isotope record from a thorium-uranium-dated stalagmite from Shanbao Cave at Shennongjia reflects variations in the amount of monsoon precipitation for the period from 11.5 to 2.1 ka （1 ka = 1000 cal aBP）. Between 11.5 and 9.3 ka, a sharp decrease in 5180 indicates a rapid increase in monsoon precipitation. An interval of generally high monsoon precipitation is observed between 9.3 and 4.4 ka. An arid period has prevailed between 4.4 and 2.1 ka. The long-term trend of Shanbao record appears to follow summer insolation at 33°N latitude. An abrupt decrease in monsoon precipitation around 4.3 ka is synchronous with the collapse of Neolithic culture in central China. This abrupt change could have resulted from the amplification of the gradually decreased summer insolation by the positive vegetation-atmosphere-aerosol feedback. The weakened Asian monsoon events were in concert with decreased Greenland temperature during the early Holocene, centered at 8.2, 8.6, 9.3, 10.2 and 11.0 ka. This correlation suggests that changes in low-latitude monsoon are connected with climate change in high-latitude polar region.

关 键 词：全新世 亚洲季风 长期趋势 突发事件 古气候 氧同位素 中国 神龙架 石笋 

分 类 号：P532[天文地球—古生物学与地层学]