75,000 years of hydroclimate and temperature variations in East Asia derived from snail shell clumped isotopes

Guo, Jingjing , Ziegler, Martin , Dong, Jibao , Sun, Youbin , Peterse, Francien

2026-08-15 QUATERNARY SCIENCE REVIEWS 2026   386(卷), null(期), (null页)

查看原文

Changes in past East Asian climate and monsoon intensity have been inferred from a wide variety of paleoclimate archives. However, quantitative reconstruction of land surface temperatures in East Asia remains sparse. Here we present a 75-kyr temperature record derived from the carbonate clumped isotope composition (Delta(47)) of land snail shells from a loess-paleosol sequence at Yuanbao, on western edge of the Chinese Loess Plateau (CLP). Modern growing season (mid-April to September) temperature based on Delta(47) (T-47) is 21.2 +/- 1.2 degrees C. The T-47 record reveals that there are certain periods where land surface temperatures were lower: the last glacial maximum (LGM) was similar to 7 degrees C colder, Marine Isotope Stage 3 (MIS3) similar to 5 degrees C and MIS4 similar to 6 degrees C, but also the mid-Holocene was similar to 9 degrees C colder than present day. Temperatures similar to present day occurred during Northern Hemisphere Summer Insolation (NHSI) minima within MIS3 and the B & oslash;lling-Aller & oslash;d (BA). Monsoon precipitation reconstructions based on organic and inorganic geochemical proxies from the same loess-paleosol section indicate that these warm periods are characterized by relatively dry conditions. This is further supported by the relative enrichment in the temperature-independent oxygen isotope composition of snail body water (delta O-18(bw)) during these time intervals, reflecting a negative moisture balance. In contrast, the unexpected low T-47 for the mid-Holocene could be the result of wet conditions. Our record thus suggests that soil moisture availability exerts a strong influence on land surface temperatures recorded by snails stored in loess archives.