THE TERTIARY SPOROPOLLEN ASSEMBLAGE IN THE JIUQUAN BASIN AND THE PALAEOENVIRONMENT

As sporopollen is the generative cell of maternal plants, a paleo-vegetation and paleo-climate may be partially and approximately revealed by using the sporopollen spectrum. However, the characteristics of sporopollen assemblages from various Tertialry sequences in the Jiuquan Basin are approached with an alternative method to substitute a sporopollen spectrum by a sporopollen assemblage pattern. The distributive characteristics of paleo-vegetations and paleo-climates during different stages of sedimentation are inferred by sporopollen assemblage and ecologic behaviour of plants, and sporopollen differentiation index are applied to analyse the changes in the pateoenvironments for various sequences. Thus the paper has revealed an internal relationship between sporopollen vegetation and paleoenvironment, which can provide scientific basis for petroleum exploration and research.