An absolute-dated, bi-decadal-resolution, stalagmite oxygen-isotopic time series from Shigao Cave reveals the evolution of summer monsoon precipitation over the past 9.9 ka BP in northern Guizhou Province, Southwest China. The 18O-inferred climate conditions are divisible into three distinct stages: (1) a maximum humid era from 9.9-6.6 ka BP; (2) a gradual declining precipitation interval between 6.6-1.6 ka BP; and (3) a relatively low precipitation time window after 1.6 ka BP. Consistency of contemporaneous stalagmite Holocene 18O records between Shigao and other caves in the Indian and East Asian monsoon realms support the effect of primary orbital solar forcings on monsoonal precipitation. However, statistical analysis shows a significant spatial asynchroneity of the Holocene Optimum termination in the Asian monsoon territory. The Holocene Optimum ended at 7.2-7.4 ka BP in Oman, located in the Indian monsoon region, and at 5.6-5.8 ka BP in Central China, in the East Asian monsoon zone. In Southwest China, the termination occurred between these periods, at 6.6-7.0 ka BP, and was influenced by both monsoon systems. We propose that this spatially asynchronous ending of Holocene Optimum in Asia may be attributed to sea surface temperature changes in the western tropical Pacific, which is a primary moisture source for the East Asian monsoon.
从 Sanbao 洞的一个石笋氧同位素记录，中国，与 7 230Th 年龄和 355 氧同位素数据建立了，在现在( ka BP )前从 284～240 千年为时期向东方亚洲季风(电动会计记帐机)紧张的连续历史提供 34 ka 的典型错误。这个新记录扩大以前出版的石笋 18O 记录回到海洋的氧同位素阶段(MIS ) 8。MIS8 电动会计记帐机记录广泛地跟随导致 orbitally 的曝晒变化并且被至少 6 标点强壮 -- 并且 3 个弱季风的事件。在结束 III (TIII ) 附近的弱季风事件在 257 ka BP， 253 ka BP 和 246 ka BP 被标明日期，并且能清楚地被相关到三冰木排碎片(IRD ) 在北方大西洋的事件。TIII 看起来显示二阶段的冰川的结束进程，类似于 TI 和 TII 的。阶段我被与完整的大气的 CO2 集中和南极温度上升是同时代的几几千年(250244 ka BP ) 的一个弱季风阶段描绘。阶段 II 被很快加强的季风在 244 ka BP 标记，由 CH4 集中和大气的 CO2 集中的快速的增加伴随了。我们的观察支持北半球(NH ) 夏天曝晒触发了的 Milankovitch 理论冰川间冰期的周期。另外，我们的结果建议南部的半球(嘘) 温暖可能在 TIII 便于 AM 的结束。
