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对贵州七星洞的石笋进行了TIMS铀系测年和氧同位素组分分析, 建立了最近7.7 ka石笋δ-18O值的变化序列. 重建了贵州地区7.7 kaBP以来的季风气候变化: 7.7～5.8 kaBP, 适宜期内的夏季风强盛期; 5.8～3.8 kaBP, 夏季风的稳定减弱期; 3.8～0.15 kaBP, 减弱的夏季风及气候大幅波动期. 并指出7.7 kaBP以来石笋δ-18O值增加趋势既反映了北半球夏季太阳辐射减少引起的夏季风减弱, 也反映了西南季风降雨对该地区的贡献相对减少, 这与模拟结果所表明的西南季风强度变化相一致; 而δ-18O值大幅度的波动变化则可能表明与降雨量变化相联系的不同季风降水云团对该地区降雨贡献的剧烈变化.
The TIMS uranium dating and oxygen isotopic composition analysis of stalagmite in Qixing Cave of Guizhou Province were carried out to establish the sequence of δ-18O value of stalagmite in recent 7.7 ka period.The monsoon climate change since 7.7 kaBP in Guizhou Province was rebuilt: 7.7 ~ 5.8 kaBP, The summer monsoon intensity period in the suitable period, 5.8 ~ 3.8 kaBP, the stable weakening period of the summer monsoon, 3.8 ~ 0.15 kaBP, the weakened summer monsoon and the period of sharp fluctuations of climate.It also points out that the trend of δ-18O value of stalagmite increase since 7.7 kaBP The decrease of summer monsoon due to the decrease of summer solar radiation in the northern hemisphere also reflects the relative decrease of contribution of southwest monsoon rainfall to the area, which is consistent with the change of intensity of southwest monsoon indicated by the simulation results. However, the δ-18O value fluctuates greatly It may indicate a dramatic change in the contribution of different monsoon precipitation clouds to rainfall in the area linked to changes in rainfall.