Acta Scientiarum Naturalium Universitatis Pekinensis

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Paleoclimatic Events from 40 to 46ka B.P. Based on Stalagmite Records in Eastern Chongqing, China

DONG Mingxing1, LUO Kunli1, CHEN Qiao1, LI Shuwen2, YE Chengli2, LIU Qiang2   

  • Received:2005-05-12 Online:2006-03-20 Published:2006-03-20



Abstract: The w(Mg)/w(Sr) ratio in a stalagmite, which is directly proportional to DMg/Ca, the solid-liquid distribution coefficient of Mg, is proposed as a geochemical thermometer to estimate paleoclimatic changes. The palaeoclimatic changes in Eastern Chongqing in the last glaciation from 46 to 40kaBP have been reconstructed by using this thermometer in stalagmite(No. ZNSD17) from Furong Cave, Wulong county. The climate changes can be divided into three periods: warm(46-44.6kaBP), cool and wet(44.6-40.6kaBP), hot and dry(40.6-40kaBP). A high resolution between 51 and 135 years of w(Mg)/w(Sr) thermometer clearly displays a cool event (Heinrich Event 4) occurring in 41.42kaBP and 3 warm events (IS8, IS9 and IS10) occurring at 40, 45, and 45.7kaBP respectively. These results are well correlated with the preceding data within the range of errors.

Key words: Eastern Chongqing, 40-46kaBP, w(Mg)/w(Sr) records, Heinrich Event 4, stalagmite

摘要: 石笋的 w(Mg)/w(Sr) 值与Mg的固液分配系数 DMg/Ca 直接相关,可作为估算古温度变化的地球化学温度计。用武隆县芙蓉洞的石笋中的Ca、Mg、Sr地球化学值重建了重庆东部40~46kaBP的古气候变化。古气候重建结果显示:46~44.6kaBP为温凉期;44.6~40.6kaBP为持续稳定的冷湿期;40.6~40kaBP为干热期。分辨率达51~135a的古温度曲线清晰地显示了41~42kaBP时期的Heinrich事件H4和在40、45和45.7kaBP的3个暖事件(IS8,9,10),该结果与前人资料在误差范围内有很好的吻合。

关键词: 重庆东部, 40~46kaBP, w(Mg)/w(Sr)记录, Heinrich事件4, 石笋

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