A mid-Holocene stalagmite multiproxy record from southern Siberia (Krasnoyarsk, Russia) linked to the Siberian High patterns

• Published in: Quaternary Science Reviews
• Main Authors: A. Columbu, L. V. Zhornyak, G. Zanchetta, R. N. Drysdale, J. C. Hellstrom, I. Isola, E. Regattieri, A. E. Fallick
• Other Authors: Columbu, A., Zhornyak, L. V., Zanchetta, G., Drysdale, R. N., Hellstrom, J. C., Isola, I., Regattieri, E., Fallick, A. E.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2023
• Subjects: Stable isotopes; Fluorescence; Speleothems; Siberian high; Holocene; Permafrost; Paleoclimate; 4.2 event; Greenland; Greenland ice cores; Ice; North Atlantic; permafrost; Siberia
• Online Access: https://hdl.handle.net/11568/1206730; https://doi.org/10.1016/j.quascirev.2023.108355

A multiproxy record from a stalagmite collected from Torgashinskaya Cave (Southern Siberia, Russia) and growing between ca. 6 and 3.8 ka shows evidence for regional climatic changes occurring at ca. 5 ka. Inter- pretation of stable isotope ratios (δ18O and δ13C) and fluorescence data (intensity and wavelength of the emitted fluorescence) suggests that the interval between ca. 5 and 4.2 ka was generally warmer and drier than the in- terval between ca. 6 and 5 ka. The observed bipartitioning of the climate, attributable to the so-called ‘middle- late Holocene transition’, has a striking similarity to changes in K+ and Na+ concentration of Greenland ice cores (taken as indicators of the strength of the Siberian High and Icelandic Low, respectively), in the abundance of hematite-stained grains in subpolar North Atlantic sediments and, to lesser extent, in the summer Asian monsoon 18 18 intensity deduced by δ O from Chinese speleothems. In particular, the δ O record at Torgashinskaya Cave can be interpreted as mostly driven by temperature changes. Besides several episodes of drift towards higher tem- peratures, it also strongly suggests the presence of short cooling events centered at 4.1+0.08/-0.07, 4.85+0.05/-0.06, 5.1+0.09/-0.09, 5.3+0.08/-0.07 and 5.8+0.12/-0.13 ka. Notably, the last three such events are in very good corre- spondence with spikes in the K+ and Na+ concentration of Greenland ice cores. Instead, the cooling around 4.1 ka could be the local response to the 4.2 event, a cold/dry episode identified in several records in the Northern Hemisphere. This suggests that δ18O of speleothem calcite from this area could be a useful proxy for defining the evolution of the Siberian High and its effect on the wider regional climate.