The Red Bed Sporo-pollen Assemblages and Geological Age from Zhuerzhuang of Yaojie, Gansu

This paper includes a systematic analysis and correlation study on the sporo-pollen assemblages, stratigraphic sequence and geochronology of the Zhuerzhuang Red Bed Sections in Yaone, Gansu. From the bottom to the top of the Zhuerzhuang section there are three sporopollen assemblages: ① Liqudambarpollenites - Meliaceoidites assemblage, which belongs to Early Mid Eocene; ② Saliaxipollenites-Celtis pollenites-Fraxinoipollenites assemblage, which may be assigned to Mid -Late Eocens; ③ Quercoidites - Saliaxipollenites- Fraxinoipollenits assemblage,which may belong to Late Eocene-Early Oligocene. The results of this study show that, the geological age of the Red Bed section belongs to Eocene-Early Oligocene; the Eocene sporopollen assemblages of Yaojie are approximately similar to those of the East region and the West region of China, which indicate subtropical broadleaved deciduous forest mainly composed of the subtropical and warm temperate taxa, and burning hot climate; from Late Eocene to Early Oligocene, the vegetation of Yaojie evolved to warm temperate mixed broadleaf and needleaf forests mainly composed of the warm broadleaf deciduous plant, presumably associated with warm and humid conditions.