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根据松辽盆地梨树断陷早白垩世地层中孢粉百分含量的纵向变化特征,建立了自下而上各层组的孢粉组合。通过分析孢粉、藻类以及介形类的古环境指示特征,恢复了梨树断陷地层的气温带、古植被、干湿度以及湖水古盐度。沙河子组沉积时期为温暖潮湿的中亚热带气候,古植被为针叶林和灌草丛,湖水为淡水、微咸水;营城组沉积时期为南亚热带气候,古植被为针叶林和灌草丛,湖水同样为淡水、微咸水;到了登娄库组沉积时期,气候变得炎热干旱,为热带气候,古植被为针叶林,湖水则变为半咸水。本文的研究结果可以有效指示地层的划分与对比以及沉积环境的分析。同时,结合盆地发育讨论了古气候变化的控油意义,古气候的变化控制着烃源岩和储层的发育与分布。
According to the vertical variation of the percentage of sporopollen in the Early Cretaceous strata in the Lishu Fault Depression, Songliao Basin, the sporopollen assemblage in each layer from bottom to top was established. By analyzing the paleoenvironmental indications of sporopollen, algae and ostracods, the temperature zone, ancient vegetation, dry-wetness and salinity of the lake were restored. The sedimentary period of Shahezi Formation is a warm and humid sub-subtropical climate. The ancient vegetation is coniferous forest and shrub grassland. The lake water is freshwater and brackish water. The Yingcheng Formation deposited in the south subtropical climate and the ancient vegetation is coniferous forest and shrub grass The lake water is also freshwater and brackish water. By the time of Denluxu Formation sedimentation, the climate became hot and dry with tropical climate. The ancient vegetation was coniferous forest, and the lake became brackish water. The results of this paper can effectively indicate the stratigraphic division and contrast as well as the sedimentary environment analysis. At the same time, the significance of oil control of paleoclimate changes was discussed in combination with the development of the basin. The changes of paleoclimate control the development and distribution of source rocks and reservoirs.