甘肃窑街朱儿庄红层孢粉组合与地质时代

对窑街朱儿庄红层的孢粉和地层层序及时代进行了系统分析与对比研究。在朱儿庄红层剖面中划分出３个孢粉组合:①枫香粉属－楝粉属组合，时代为早－中始新世；②柳粉属－朴粉属－粉属组合，属始新世中、晚期；③栎粉属－柳粉属－粉属组合，属晚始新世－早渐新世。研究表明:窑街地区朱儿庄红层始新世孢粉组合与中国东、西部地区孢粉组合相似，均发育以亚热带和暖温带植物为主的亚热带型落叶阔叶林，气候炎热；始新世晚期至早渐新世则演变为以暖温带落叶阔叶树种为主的针阔叶混交林植被，气候温暖湿润。

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.