A stalagmite with high 238U content from Yangkou Cave, China, revealed the evolution of the Asian summer monsoon (ASM) between 49.1 and 59.5 ka, and the δ18O values recorded Dansgaard/Oeschger (D/O) events 13-17. The Yangkou record shows a relatively gradual transition into the D/O 14 and 16 events. The discrepancy between the abrupt and gradual transitions of D/O 14 in the records from northern and southern China, respectively, suggests different responses of the ASM to climate changes in the high northern latitudes. The higher resolution δ18O record and more precise 230Th dating indicate that the timing of D/O 14 and 17 in the Hulu records at 53 and 58 ka should be shifted to 54.3 and 59 ka, respectively. The gradual strengthening of the ASM at the onsets of D/O 16 and 14 in our record is different from the abrupt temperature rise in the northern high latitudes. Some other factors must contribute to this relatively gradual ASM change in southern China, but the actual reason is still unknown.
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Great thanks to the editors Matthew Lachniet and Derek Booth and the anonymous reviewers for their constructive suggestions and comments to improve the manuscript. A professional English translator, Dr. Xiang Xinyi, Southwest University, China, is also greatly appreciated for her effort in polishing the manuscript. This research was supported by National Natural Science Foundation of China (Nos. 41172165, 41302138, and 41440020), "the Fundamental Research Funds for the Central Universities" (Nos. XDJK2013A012, XDJK2014C010, and XDJK2017A010), "Karst Dynamics Laboratory, MLR and GZAR" (No. KDL201301), and the open project of the "State Key Laboratory of Loess and Quaternary Geology" (No. SKLLQG1310) to T.-Y. Li and J.-Y. Li. This study was also supported by a Taiwan Ministry Of Science and Technology (MOST) grant (103-2119-M-002-022) to C.-C. Shen.
© University of Washington. Published by Cambridge University Press, 2017.
- Asian summer monsoon
- Dansgaard/Oeschger events
- Stalagmite δO
- Th dating