Imprints of Millennial-Scale Monsoonal Events during the MIS3 Revealed by Stalagmite δ 13 C Records in China

• Published in: Geosciences
• Main Authors: Rongyu Shen, Peng Zhang, Jiaqi Cong, Jing Liao, Xuelin Luo, Liangcheng Tan, Jinguo Dong, Yijia Liang
• Format: Article in Journal/Newspaper
• Language: English
• Published: MDPI AG 2023
• Subjects: the Chinese Loess Plateau; cave stalagmite; carbon isotopes; Marine Isotope Stage 3; abrupt climate events; Geology; QE1-996.5; Greenland; Greenland ice core; ice core; North Atlantic
• Online Access: https://doi.org/10.3390/geosciences13050136; https://doaj.org/article/a3a6aeb4755b408398dd898f055093c7

Regions located on the Chinese Loess Plateau are sensitive to changes in the Asian monsoon because they are on the edge of the monsoon region. Based on six 230 Th experiments and 109 sets of stable isotope data of LH36 from Lianhua Cave, Yangquan City, Shanxi Province, we obtained a paleoclimate record with an average resolution of 120 years from 54.5 to 41.1 ka BP during the MIS3 on the Chinese Loess Plateau. Both the Hendy test and the replication test indicated an equilibrium fractionation of stable isotopes during the stalagmite deposition. Comparison with four other independently-dated, high-resolution stalagmite δ 13 C records between 29°N and 41°N in the Asian monsoon region shows that the stalagmite δ 13 C records from different caves have good reproducibility during the overlapped growth period. We suggest that speleothem δ 13 C effectively indicates soil CO 2 production in the overlying area of the cave, reflecting changes in the cave’s external environment and in the Asian summer monsoon. Five millennial-scale Asian summer monsoon intensification events correspond to the Dansgaard–Oeschger 10–14 cycles recorded in the Greenland ice core within dating errors, and the weak monsoon processes are closely related to stadials in the North Atlantic. The spatial consistency of stalagmite δ 13 C records in China suggests that the Asian summer monsoon and the related regional ecological environment fluctuations sensitively respond to climate changes at northern high latitudes through sea-air coupling on the millennial timescale.