1. A Highly Resolved Speleothem δ 13 C Record from Central China and Its Manifestation on Multiple Time Scales during the Last Glacial.
- Author
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Chen, Qingmin, Cheng, Xing, Deng, Li, He, Kaikai, Zhang, Wenshuo, Xue, Gang, Zhang, Zeke, Ma, Le, Wang, Gaohong, Cheng, Hai, and Edwards, R. Lawrence
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SPELEOTHEMS ,LAST Glacial Maximum ,HILBERT-Huang transform ,WATER-rock interaction ,PALEOHYDROLOGY - Abstract
Speleothem δ
13 C in monsoonal China differs from speleothem δ18 O, which is widely used as a climatic proxy for several complex control reasons. Nevertheless, δ13 C records have the potential to reveal the implications of hydroclimatic changes. This study reports a speleothem δ13 C record from Didonghe (DDH) Cave in central China spanning 34 to 13 kyr BP. After we investigated the factors that influence speleothem δ13 C, we found that the δ13 C record showed that DDH Cave can prompt directional shifts via local hydroclimatic changes, such as in vegetation types, biomass, and rock–water interaction processes, suggesting that δ13 C is mainly controlled by the local hydroclimate. Ensemble empirical mode decomposition (EEMD) results revealed a coupling relationship between δ18 O and δ13 C on multiple timescales, which suggested that changes in precipitation caused by large-scale monsoonal circulation are controlled by regional hydrological conditions to a great extent. However, the hydrological conditions of the cave were relatively mild and humid during the last glacial maximum (LGM), which revealed the impact of evaporation on changes in the region's hydrological conditions. We also found that the δ18 O and δ13 C profiles decoupled when δ13 C changed with a shift in the location of the westerly during HS1. The δ13 C record correlates well with other paleoclimate records, suggesting that regional hydrological conditions are also modulated by the Earth's internal and external driving factors. [ABSTRACT FROM AUTHOR]- Published
- 2024
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