Coupling Between High-and Low-latitude Climate And Stable Isotopic Records From Shennongjia During The Holocene

The East Asian monsoon is an active component of atmospheric circulation and plays a significant role in the global hydrologic and energy cycles. High-resolution absolute-dated record of the stalagmite is one of main footstones to unravel past global changes. Here, we present a speleothem oxygen isotope record, using 2144δ¹⁸O data and 82 U/Th dates measured from 9 stalagmites collected from Shanbao Cave at Shennongjia, central China.Our record provides a ²³⁰Th-dated high-resolution climate record of the East Asian monsoon during the whole Holocene.When varying between 10μm/a and 120μm/a , growth rate is no relation with isotope equilibrium fractionation.Theδ¹⁸O records from Shanbao Cave are duplicated well during the overlapped intervals, with similar amplitude of 1‰for millennial oscillation. For times of contemporaneous deposition of stalagmites, Shanbao records replicate remarkably well with Hulu, Dongge and Qunf cave records, indicating that the stalagmiteδ¹⁸O reflects well a large-scale circulation of Asian summer monsoon winds and their related precipitation, and we find out that the average value of stalagmiteδ¹⁸O decreases northword with an increase in latitude from 17°N to31°N . Theδ¹⁸O values vary between -10.5 and -8‰, with averaging values -9.7‰, which is lower thanδ¹⁸O values averageing -2‰and -8‰from stalagmite Q5 and DA, respectively. In early-mid Holocene, The varied amplitudes of theδ¹⁸O are relative smaller than in the late Holocene. During the late 13ka, the long-term trend of the shanbao cave record correlates the summer insolation at 65°N latitude. Moreover, peak monsoon intensity and peak insolation values do exactly coincide when they do in the last interglacial. By comparing high-resolutionδ¹⁸O records of stalagmite from the Shanbao cave (Hubei) with that from the Qunf cave (Oman), and the Dongge cave (guizhou), we find out that The long-term trends from three stalagmites records agree each other well, suggesting the broad deline in Asian monsoon intensity during the Holocene was directly controlled by the orbitally-induced lowering of summer insolation affecting gradual southward migration of Intertropical Convergence Zone.In summary, the well-dated high-resolution monsoon record, for the first time, provides direct evidence that there is a more precise correlation between AM and Greenland climate on centennial time scales during the early Holocene. The transition of the mid-holocene /deglacial period in our record can be recognized three stepwise stages, which is in phase with that ofδ¹⁸O record from Greenland ice cores. The marked similarity between both records indicates that early Holocene Asian Monsoon intensity was controlled on centennialtime scales by glacial boundary foring. The long-term trend ofδ¹³C records was similar with that of the GISP2δ¹⁸O records andδ¹³C of stalagmite DA from Guizhou province, indicating the stalagmiteδ¹³C may reflect changes in soil CO₂ production in milliennial scale and changes of vegetation types during the glacial/interglacial period.