Effect of palaeoclimate change at the late Cretaceous period on lithologic sequences in Songliao basin

On the study on distributional characteristics of sporopollen assemblage and geochemical data at the late Cre- taceous period in Songliao basin,the paleoclimate was recov- ered.The result indicates that the palaeoclimate change is classified into two cycles.,from xerothermic to humit to xe- rothermic.The cycles above are well corresponding with the cycles of two secondary sequences interpreted from the li- thology,the electrical property and seismic data.The cyclic change of palaeoclimate results in the changes of lacustrine level and sediment supply,consequently affecting the devel- opment of lithologic sequence.The palaeoclimate change of each cycle affects the changes of the low-stand systems tract (LST),transgressive systems and high-stand systems tract (HST),and also controls the accumulation model of deposits and the distribution of sedimentary facies.