广西百色盆地始新世孢粉组合与环境

EOCENE PALYNOLOGICAL ASSEMBLAGES AND ENVIRONMENTS IN THE BAISE BASIN OF GUANGXI

对百色盆地百东河地表始新世剖面进行系统孢粉分析 ,建立那读组和百岗组连续的孢粉序列 ,共划分 6个孢粉带和 11个亚带。根据剖面孢粉母体植物的生态属性 ,确定 6个孢粉植物群—气候期。当时植被经历了由常绿阔叶林向常绿落叶阔叶混交林转变 ;气候从热带湿润型向南亚热带—北热带半湿润偏干型转变。

A systematic palynological analysis was carried out of the Eocene Baidonghe section in the Baise Basin, Guangxi of South China. A continuous palynological sequence was established in the Nadu and Baigang Formations, and 6 palynological zones and 11 subzones were recognized. 6 palyno-flora—climate stages were divided mainly based on the ecological nature of the representative parent plants in palynological spectrum of the section. Evidence shows that the Eocene vegetation in the study area experienced a ge- neral transition from an evergreen broad-leaved forest to a mixed evergreen and deciduous broad-leaved forest. The inferred climate also changed from the tropical humid type to the south subtropical-north tropical semi-humid one.