贵州荔波地区2000年来石笋高分辨率的气候记录

通过对荔波董哥洞石笋进行高精度的ICP MS或TIMS U系测年和碳、氧同位素分析，建立了荔波地区2 300a B.P.来高分辨率的古气候变化的时间序列。研究结果表明，贵州荔波地区2 300a B.P.以来石笋记录的季风气候变化，大致可分为8个气候(亚)期:① 2 300～1 800a B.P.为降温期，显示东亚夏季风减弱，东亚冬季风增强，气候干旱寒冷；② 1 800～1 080a B.P.气温有所回升，显示东亚冬季风缓慢减弱，东亚夏季风有所回升，表现为半湿润的温凉气候期；③ 1 080～680a B.P. 为降温期，气温再次下降，显示东亚冬季风再次增强，但降水相对增大，表现为寒冷湿润的气候期，是气候变化的关键转折时期；④ 680～550a B.P.温暖期，显示东亚夏季风再次增强，气温升高，降水增大，表现为温暖湿润的气候期。⑤ 550～400a B.P.寒冷期，显示东亚冬季风快速增强，气温下降，表现为寒冷湿润的气候环境，是近1 000年以来最冷的时期；⑥ 400～364a B.P.温凉期，显示东亚夏季风有所增强，气温有所回升，表现为温凉湿润气候环境；⑦ 364～324a B.P.冷凉期，显示东亚夏季风有所减弱，气温有所下降，表现为冷凉湿润气候环境；⑧ 324a B.P.至今，气候相对波动期，同位素记录曲线呈锯齿状波动，在其内包括若干个冷凉半湿润、冷湿的气候变化亚阶段。根据荔波董哥洞石笋的高分辨率的古气候变化的连续记录，揭示了荔波地区2 300a B.P.以来的一些百年尺度的重大气候事件——干旱寒冷期、隋唐温暖期(或小温暖期)、小寒冷期以及一些十年尺度的降水、温度变化。石笋记录的这种百年、十年尺度的突发性气候变化事件，与冰芯记录极为相似，反映低纬度地区石笋记录的季风气候与高纬度及北极地区的气候具有极好的相关性，这对于认识现代气候系统变化以及对未来十年—百年尺度的气候预测和演化的驱动机制，具有重要的科学意义。

High-resolution Climatic Record from a Stalagmite in the Past 2000 Years in Libo, Guizhou Provience

The time sequence of high resolution paleoclimatic change since 2 300 a B.P.has been reconstructed by dating ages of the high precision ICPMS or TIMS-U series and the analysis of the carbon and oxygen isotopes from a stalagmite of Dongge cave in the area of Libo,Guizhou.The study showed that the records of the warm and cold events from a stalagmite since 2 300 a B.P.in the area of Libo reflected the paleoclimatic change which can be divided into eight stages:(1) Falling temperature stage from 2 300 a B.P.to 1 800 a B.P.showed that the East Asian summer monsoon became weakly and winter monsoon became strongly,the air temperature gradually fallen,the available rainfall reduced,and they represented the dry and cold climate environment;(2) Rising temperature stage from 1 080 a B.P.indicated that the East Asian winter monsoon slowly weaken 1 800 a B.P.to and summer monsoon slightly strengthened,and they represented the semi-humid and warm-cool climate environment.(3) Dropping temperature time from 1 080 a B.P.to 680a B.P.showed that the winter monsoon strengthened again,the air temperature reduced again,and the available rainfall relatively increased in winter,and they represented the cold and humid climate environment.This stage was the key transition period of climate change.(4) Warm period from 680 a B.P.to 550 a B.P.revealed that the East Asian summer monsoon strengthened again,the air temperature rose,the available rainfall relatively increased in summer,and they represented the warm and humid climate environment.(5) The cold period from 550 a B.P.to 400 a B.P.indicated that the East Asian winter monsoon rapidly strengthened,the air temperature quickly dropped and the available rainfall increased a lot,and they represented the cold and humid climate environment.This stage was the coldest stage in the last 1000 years.(6) Warm-cool period from 400 a B.P.to 364 a B.P.revealed that the East Asian summer monsoon slightly strengthen,the air temperature slightly increased,and they represented the warm-cool and humid climate environment.(7) The cold-cool period from 364 a B.P.to 324 a B.P.indicated that the East Asian winter monsoon slightly strengthen,the air temperature slightly dropped,this period was the cold-cool and humid climate environment.(8) The relatively fluctuation stage of climate change from 324 a B.P.up to the present revealed that the East Asian monsoon frequently changed,the curve of isotope records submitted the serrated undulations,which included some sub-stages of the cold-cool and semi-humid,cold and humid climate changes.Some key centural-scale climate events,for example the dry-cold period,Suitang warm period,little warm and cold period,and some changes of precipitation and temperture in the ten,century time scale has been revealed since 2 300 years in Libo area according to the continuous record of high resolution paleoclimatic change from a stalagmite.The abrupt events of climatic change in the ten,century time scale from a stalagmite record has an analogy with the events of the ice core records,and reflected that the monsoon climate from stalagmite records in the low latitude region is provided a wonderful relativity with the climate change in the high latitude region and the arctic pole.The above study has the important scientific significance for knowing the change of modern climate system,climatic forecast and driving mechanism of climatic evolution in the future.