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 biogenie 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. Copyright by Science in China Press 2005.
- Hulu cave
- Last glacial period