云贵高原晚新生代孢粉植物群与环境变迁

LATE CENOZOIC PALYNOFLORA AND ENVIRONMENT CHANGES IN YUNNAN-GUIZHOU PLATEAU

本文依据２０多个剖面（钻孔）近７００个样品的孢粉资料及古地磁极性年表建立了云贵高原４Ｍａ以来的孢粉时间序列，并划分了四个区域孢粉组合带，１７个孢粉组合亚带。依据孢粉混杂堆积的出现，认为云贵高原的上升始于２．８ＭａＢ．Ｐ．，加剧于０．８ＭａＢ．Ｐ．前后。前期地形相对高度＜１０００ｍ，后期相对高度达１５００ｍ；地貌经历了开阔盆地－低洼盆地－山地湖盆－高山湖盆的演化。气候经历了古季风、现代季风的发展过程。

Yunnan-Guizhou Plateau has unique information of Late Cenozoic sporopollen. Inthis paper,we established pollen time series from 4 Ma.B.P.based on paleomagnetictime scale,and divided the regional pollen assemblages into 4 zones and 1 7 sub-zones.Based on the chaotic pollen sediment,we considered that the uplift of Yunnan-GuizhouPlateau began in 2.8 Ma.B.P. Along with the uplift of mountains,the climate in thisarea was first controlled by the Pacific airflow,then affected by Indian Ocean airmassand south part of westerly jet,and then evolved to modern monsoon.And a dry-hot val-ley was formed.