MICROPALAEONTOLOGICAL ASSEMBLAGES IN SONGNAN WELL NO.15 AND STRATIGRAPHICAL SIGNIFICANCE

In recent year, the author has obtained a lot of sporopollen, Charaphy-ta, and Ostracoda from the first member of Nenjiang Formation and the Qi-ngshankou Formation in Songnan Well No.15 located in the Huaide County, Jilin Province, and carried out a detailed study on them.Among the fossils, the sporo-pollens are especially rich, which may be divided into an assemlage sub/one and an assemblage zone, in ascending order as follows: l.Schizaeoisporites-Tricolporopollenites assemblage zone 2.Proteacidites-Schizaeoisporites assemblage subzone The first member of Nenjiang Formation is the representative strata of Proteacidites-Schizaeoisporites assemblage subzone.The Schizaeoisporites-Tricolporopollenites assemblage zone represents the strasa of the Qingshan-kou Formation.The two sporo-pollen assemblages provided the reliable bi-ostratigraphical basis for dividing and correlation of strata and distinguishing the suite of seismic reflection wave, on which the strata in Songnan Well No.15 were redivided and the suite of seismic reflection waves was revised(see table 2).