【摘要】 无论孢粉类型还是孢粉数量,昌五地区沙河子组发现的孢粉化石均可称得上是松辽盆地北部同层位中最丰富的。研究区沙河子组自下而上可以划分出两个孢粉组合:克拉梭粉(Classopollis)-拟云杉粉(Piceites)组合和三角瘤面孢(Lophotriletes)-无突肋纹孢(Cicatricosisporites)组合。其组合特征明显,可以作为研究区内地层划分对比的生物地层学依据之一。孢粉组合研究结果表明,沙河子组的地质时代应为早白垩世凡兰吟期-欧特里夫期(Valanginian-Hauterivian)。尽管没有出现最原始的被子植物花粉,但也不排除部分进入巴列姆期(Barremian)的可能。更多还原

【Abstract】 Palynological fossils found in the Shahezi Formation in Changwu area are the most abundant of the same horizon in the north part of the Songliao Basin. It can be divided into two palynological assemblages in the study area from bottom to top: (1)ClassopollisPiceites Ass. and (2)LophotriletesCicatricosisporites Ass. The first palynological assemblage was characterized by high percentage gymnosperm pollens (71.3%～85.7%) which was mainly composed of  Classopollis annulatus, Inaperturopollenites sp., Piceites sp., Piceaepollenites sp., Pinuspollenites sp., etc., abundant fern spores (14.3%～28.3%) which included Cyathidites minor (0%～8.0%), Granulatisporites sp.(0%～8.0%), Osmundacidites welmnnii(4.0%～7.2%), Cicatricosisporites australiensis (0.8%～4.0%), etc. and no angiosperms. The second was characterized by high percentage fern spores (83.8%～85.0%) which was mainly composed of Granulatisporites sp.(8.3%～25.2%), Lophotriletes sp.(13.3%～25.2%), Cicatricosisporites australiensis(1.8%～28.4%), Cyathidites minor (3.3%～15.3%), Converrucosisporites sp.(0%～12.6%), etc., abundant gymnosperm pollens (15.0%～16.2%) which included Classopollis annulatus(0.9%～1.7%), Exesipollenites sp.(0%～3.3%), Paleoconiferus sp.(0%～2.7%), etc. and no angiosperms. The character of the two assemblages is very clear and can be used to divide the strata. The age of the Shahezi Formation should be Early Cretaceous Valanginian-Hauterivian according to the palynological data. Some part might be of Barremian in age, although no angiosperm pollens have been found.更多还原