中文摘要：

为探讨洞穴次生碳酸盐沉积U元素含量变化的气候环境意义,以川东北狮子洞石笋SI3为研究对象,通过对SI3的U/Ca值进行分析,发现在53.2~45.8ka之间SI3的U/Ca值变化与该石笋和格陵兰冰心NGRIP的δ^18时期偏大,在夏季风增强时期偏小。此外U/Ca值很好地记录了H5冷事件和GIS12、GIS13及GIS14暖事件。

英文摘要：

The U/Ca ratio of the stalagmite SI3,collected from the Shizi cave in the northeast Sichuan province,was investigated to explore the paleoclimatic and paleoenvironmental implications of speleothem U concentrations. The results indicated that the SI3 U/Ca ratio is positively correlated with its oxygen isotope（ δ^18） and the NGRIP ice core δ^18 records with higher U/Ca ratios corresponding to stronger summer monsoon and otherwise to weaker summer monsoon. Thus,the U/Ca ratio of the speleothem SI3 is an appropriate proxy for the East Asian Summer Monsoon（ EASM） variations when soil is at redox conditions,which was largely controlled by soil moisture and EASM strength.