WANG Baoyan1,2, YANG Xunlin1,2, SUN Xili1,2, SHI Zhichao1,2, LIU Ruikai1,2
（1.Chongqing Key Laboratory of Karst Environment, School of Geographical Sciences, Southwest University, Chongqing, 400715, China;
2.Field Scientific Observation & Research Base of Karst Eco-environments at Nanchuan in Chongqing, Ministry of Land and Resources of China, Chongqing 408435, China）
Abstract: We reconstructed the paleoclimate evolutionary sequence in the Asian Summer Monsoon area from 9.6 to 1.6 ka B.P. on the basis of 13C data collected from a continuous growing stalagmite (J119) collected in the Jinfo Cave, Chongqing, China. In the period of from 9.6 to 7.4 ka B.P., the δ13C of J119 showed a negative trend, indicating the East Asian monsoon strengthened gradually and the climate became warm and wet. In the period of from 7.4 to 4.2 ka B.P., the δ13C of J119 turned to be very negative, corresponding to the Holocene Thermal Optimum. In the period of 4.2 to 2.5 ka B.P., the δ13C of J119 showed a continuous positive trend, revealing that the climate became dry and cold. After 2.5 ka B.P., the δ13C of stalagmites turned to be negative slightly, indicating the climate became warmer. The Jinfo mountain experienced 7 times of millennial climate oscillation, occurred at 2.7, 4.2, 5.5, 8.3 and 9.4 ka B.P., respectively, in the Holocene, which corresponded to Bond 2-6 events (the north Atlantic hematite record). In addition, the δ13C of J119 recorded significant other two climate oscillations of 6.7 ~ 7.0 ka B.P. and 7.3 ~ 7.8 ka B.P.. Combined with other published stalagmite records in the Asian Summer Monsoon region, the weak monsoon events recorded by δ13C of J119 consisted well with those recorded by oxygen isotopes. Therefore, this study further showed that δ13C of Jinfo Mountain stalagmite could record millennial scale climate events in the Holocene and could be verified by the stalagmites δ18O records.
Key words: Holocene; stalagmite δ13C; millennial time scale; climate oscillations; Jinfo Mountain
EARTH AND ENVIRONMENT Vol.47, No.1, Tot No.327, 2019, Page 1-9