Complicated responses of stalagmite δ13C to climate change during the last glaciation from Hulu Cave, Nanjing, China

We present a record on carbon stable isotopic composition (Δ13c), covering 75 through 10 thousands years ago (ka B.P.), from Hulu Cave, Nanjing. The overlapping Δ13c profiles are very similar in pattern and range, indicating that they mainly record climatic signal. During the last glacial-interglacial transition, the >6‰ change of Δ13c values implies different contributions of C3 vs. C4 type plants in soils. On millennial scale, however, the increased calcite Δ13c during the warm Dansgaard-Oeschger (DO) events suggests a decrease of dissolved biogenic CO2 when water flux rate through soil is large. This correlation between heavier Δ13c and higher precipitation is consistent with our previous report on the samples' stable oxygen isotope records (Wang et al., 2001). Comparison of coeval δ13C and δ18O of stalagmites indicates that kinetic fractionation of carbon isotope is closely related to growth rate of stalagmites. This study also shows that local vegetation changes may lag behind precipitation changes by～700 years during the deglaciation.

作 者： KONG Xinggong WANG Yongjin WU Jiangying CHENG Hai R. L. Edwards WANG Xianfeng   作者單位： KONG Xinggong,WANG Yongjin,WU Jiangying(College of Geography Sciences, Jiangsu Key Laboratory of Environmental Change and Ecological Construction, Nanjing Normal University, Nanjing 210097, China)

CHENG Hai,R. L. Edwards,WANG Xianfeng(Department of Geology and Geophysics, University of Minnesota, MN 55455, USA) 

刊 名： 中國科學D輯（英文版）  SCI 英文刊名： SCIENCE IN CHINA (EARTH SCIENCES)  年，卷(期)： 2005 48(12)  分類號： P4  關鍵詞： Hulu Cave   stalagmite   ??13C   last glacial period