孢粉古生态分析在层序地层学研究中的应用

APPLICATION OF SPOROPOLLEN ECOSTRATIGRAPHIC ANALYSES TO SEQUENCE STRATIGRAPHIC STUDY

不同的植物产生不同的孢粉，一定地质时期和特定的自然条件下产生的植物群与特定的孢粉组合对应，因此，孢粉组合可以指示当时的岩相古地理环境。在对伊犁盆地侏罗系孢粉组合特征及古生物图件详细研究的基础上，论证了古生物（孢粉）在层序边界上的特征。通常，层序边界上的古生物在垂向上种类和数量最少，分异度小，界线上、下之间古生物组合大不相同，是一个反映古地理环境有很大变迁的时间界面；而在最大湖泛面附近，古生物种属和数量最多，分异度大，代表了复杂的古地貌及强烈的构造运动期间的古生态组合特征。一个层序可以包含几个不同的生物带；反之，同一生物带也可包含几个层序。

Different plants produce distinct sporopollen.Special sporopollen assemblage corresponds with the flora which is produced in specific geographic time and under given natural conditions. Thus, sporopollen assemblage can indicates the lithofacies paleogeographic conditions at that time. Based on the studies of the Jurassic sporopollen assemblage features and its diagram, this paper discribes the features of sporopollen in sequence boundaries. The study shows that the paleoecology plays an important role in following areas of dividing sequence boundary,recognizing the maximum flooding surface, determining the ancient environment and reconstructing the ancient climate.