Centennial- to decadal-scale monsoon precipitation variability in the semi-humid region, northern China during the last 1860 years: Records from stalagmites in Huangye Cave

摘要

We developed a composite oxygen isotopic record of cave calcite for the last I860 years based on three stalagmites from the Huangye Cave in eastern Gansu Province, northern China.The δ~18O values reflect monsoon precipitation changes, with lower 518O values representing higher precipitation and vice versa. Three intervals of high precipitation were identified at ad 138-450, ad 730-1200, and ad 1860-1960. Two intervals of low precipitation occurred at ad 1320-1410 and ad 1530-1860. The reconstructed monsoon precipitation variations correlate well with other records further east in the eastern Yellow River Basin, suggesting synchronous precipitation changes during the late Holocene in the semi-humid region of northern China on decadal to centennial scales. Peak periods of warfare in dynastic transition times, such as at ad 391-420,ad 601-630, ad 1111-1140, ad 1351—1380,and ad 1621-1650, correspond to sharp declines in precipitation or temperature in semi-humid northern China, indicating a strong connection between climatic and societal changes. Our study suggests that climatic deterioration in semi-humid northern China has played an important role in Chinese societal evolution.