内蒙古辉腾锡勒全新世中晚期环境变迁的孢粉记录

ENVIROMENTAL CHANGES RECORDED BY POLLEN SINCE MID TO LATE HOLOCENE IN HUITENGXILE LAKE, LNNER MONGOLIA

通过对内蒙古中部辉腾锡勒湖泊沉积特征及孢粉组合特征的综合分析,重建了该地区全新世中晚期以来气候环境变化过程。研究结果表明,该地区5390 a以来气候总体上由温湿转变为冷干,具体可以分为5个阶段:5390～3970 a,以温暖偏湿气候为主;3970～3300 a,气候仍为温和偏湿;3300～2380 a,A/C比值明显降低,标志着全新世大暖期结束,凉偏干气候显著;2380～1160 a,气候转为凉湿,为大暖期结束后一个特殊湿润时期;1160 a以来气候向温凉偏干转变。

Sedimentary features and sporopollen assemblages from Huitengxile Lake located in central Inner Mongolia Autonomous Region were used to reconstruct the processes of climatic and environmental changes during mid to late Holocene.The results showed that the climate on the whole shifted from warm and humid to cold and arid over the last 5390 a,and that could be divided into 5 stages in detail： ① from 5390 a to 3970 a,the climate was warm and humid;② from 3970 a to 3300 a,the climate was moderate and humid;③ from 3300 a to 2380 a,the obvious drop of A/C ratio indicated the end of Megathermal,the climate was cool and arid;④ from 2380 a to 1160 a,the climate varied to cool and humid,which was a special humid period after Megathermal.⑤Since 1160 a,it has been mild cool and arid.