Stalagmite multi-proxy evidence of wet and dry intervals in the middle Yangtze Valley during the last glacial period

Asian monsoon intensity coupled to Antarctic climate during Dansgaard–Oeschger 8 and Heinrich 4 glacial intervals

“…In sum, from the view of modern climatology, speleothem δ 18 O is controlled by summer monsoon rainfall δ 18 O to a large extent 36 . Furthermore, both geochemical proxies and petrographic analyses of YX55 sample from the same cave, which grew during 65 and 40 ka BP, provide strong evidence that positive shifts in calcite δ 18 O correlate to dry conditions controlled by weak monsoon 40 . It is found that during HS intervals, the deposition rate of stalagmite was relatively low, along with strong prior calcite precipitation processes (indicated by high trace metal ratios), and the corresponding lithological section is composed of dense and fibrous minerals; these features are opposite from those during the DO Interstadials 40 .…”

“…Furthermore, both geochemical proxies and petrographic analyses of YX55 sample from the same cave, which grew during 65 and 40 ka BP, provide strong evidence that positive shifts in calcite δ 18 O correlate to dry conditions controlled by weak monsoon 40 . It is found that during HS intervals, the deposition rate of stalagmite was relatively low, along with strong prior calcite precipitation processes (indicated by high trace metal ratios), and the corresponding lithological section is composed of dense and fibrous minerals; these features are opposite from those during the DO Interstadials 40 . Besides, our previous review 41 on the cave records in Asia and modeling shows that two mechanisms affect stalagmite δ 18 O: changes in the fraction of monsoon rainfall in annual totals and changes in the amount of rainout between tropical sources and cave sites.…”

Northern Hemisphere Summer Insolation and Ice Volume Driven Variations in Hydrological Environment in Southwest China

“… Comparison of the YZ1 X/Ca records with paleoclimate records from different regions of China. (a) Gulang loess δ 13 C (Sun et al., 2015); (b) Zhenzhu Cave stalagmite δ 13 C (Y. X. Li et al., 2020); (c) Mangshan loess brGDGT‐derived soil pH (Peterse et al., 2014); (d) Weinan loess δ 2 H (Thomas et al., 2016); (e) Tai Lake pollen ratio of Woody/Herbaceous (Miao et al., 2015); (f) IODP U1429 planktonic foraminifer δ 18 O (gray) (Clemens et al., 2018); Haozhu cave stalagmite trace elements PC1 (bule) (Zhang et al., 2018); Dajiuhu pollen‐based mean annual precipitation (purple) (Zhang et al., 2023); Yongxing cave stalagmite Sr/Ca (orange) (Wang, Chen, et al., 2022); (g) YZ1 X/Ca PC1 (this study); (h) Pollen‐based MAP records of Caohai (green) and Tengchong‐Qinghai (pink), respectively (Zhang et al., 2023); (i) Maar lake sediments Magnetic susceptibility (Wang, Lu, et al., 2022). The red/blue bars indicate paleoclimatic records where increased/decreased insolation corresponds to decreased/increased precipitation.…”

“…During the millennial‐scale climate events of the Last Glacial Maximum (LGM), the Yangtze River basin in central China experienced wet conditions during Heinrich event (H) 1 and Younger Dryas, although the ASM weakened significantly (Zhang et al., 2018). In contrast, the environment in the central Yangtze basin was dry and cold during H5 and H6, while it was wet and warm during Greenland Interstadials (GI) 9–18 (Wang, Chen, et al., 2022). In southwest China, the regional hydrological environment and effective rainfall during H4 and H5 were comparable to or even wetter than GIs (Liu et al., 2022; Wu et al., 2023).…”

Vrba was right: Historical climate fragmentation, and not current climate, explains mammal biogeography

“…(f) Results of the number of fragmentation events, the median number, and the maximum number of fragments produced in these fragmentation events, on a global scale, differentiated by fragment size and climate zone. variations, glacial periods are globally characterized by colder and generally drier conditions than interglacial intervals (Wang et al, 2022).…”