松辽盆地梨树断陷嫩江组孢粉记录及古气候特征

Palynological Records and Paleoclimatic Characteristics of Nenjiang Formation in Lishu Fault Depression,Songliao Basin

通过对松辽盆地梨树断陷南部ZK004钻孔21.47~38.26 m段地层进行孢粉分析研究,并结合氧化物样品定量分析结果,将这段地层自下而上划分两个孢粉组合带,其中:ZK004-Ⅰ组合以Classopollis-Cedripites-Schizaeoisporites-Callistopollenites-Borealipollis为主,反映的是半湿润热带—亚热带气候向湿润亚热带气候过渡的特征;ZK004-Ⅱ组合以Cedripites-Rugubivesiculites-Schizaeoisporites-Deltoidospora-Cyathidites-Borealipollis为主,反映的是湿润亚热带气候向半湿润亚热带气候过渡的特征。其总体显示了半湿润的北亚热带气候,为该地区上白垩统嫩江组二段古气候及古植被的恢复提供了新的证据。

Based on the sporopollen analysis of the strata in the 21.47-38.26 m section of ZK004 borehole in the Lishu fault depression,Songliao basin,and combined with the quantitative analysis results of oxide samples,this stratum is divided into two sporopollen assemblages from bottom to top,of which the ZK004-Ⅰ assemblage is dominated by Classopollis-Cedripites-Schizaeoisporites-Callistopollenites-Borealipollis,reflecting the transition from semi-humid tropical-subtropical climate to humid subtropical climate;the ZK004-Ⅱ assemblage is dominated by Cedripites-Rugubivesiculites-Schizaeoisporites-Deltoidospora-Cyathidites-Borealipollis,reflecting the transition from humid subtropical climate to semi-humid subtropical climate,which generally displays semi-humid northern subtropical climate,providing new evidence for the recovery of the paleoclimate and paleovegetation of the second member of Nenjiang Formation in the Late Cretaceous.