辽河盆地大民屯凹陷沈249井早白垩世九佛堂组孢粉组合

沈249井九佛堂组孢粉材料是目前所知辽河盆地孢粉类型最丰富、数量最多且保存最完好,可确定63属,包括蕨类植物孢子40属和裸子植物花粉23属;根据孢粉组合特征,可称其为Cicatricosisporites Concavissimi sporites Classopollis孢粉组合,具有裸子植物花粉相对含量明显较高、分异性较低,而蕨类植物孢子分异性明显较高、相对含量较低的特点;该组合与辽西九佛堂组、内蒙古二连盆地赛汉塔拉组一段的孢粉组合具有很强的一致性。本文资料可弥补辽河盆地九佛堂组孢粉组合的空白,并为深入认识我国北方区九佛堂组沉积时期植物群特征提供重要的帮助。

PALYNOLOGICAL ASSEMBLAGE FROM THE EARLY CRETACEOUS JIUFOTANG FORMATION OF THE SHEN 249 WELL IN THE DAMINTUN DEPRESSION OF THE LIAOHE BASIN

Abundant and diverse spores and pollen have been found in the Jiufotang Formation of Shen 249 Well in the Damintun Depression of the Liaohe Basin, southern Liaoning Province. Sixty-three genera can be identified includ- ing 40 genera of pteridophytic spores and 23 genera of gymnospermous pollen. They are grouped into the Cicatricosisporites-Concavissimisporites-Classopollis Assemblage. Because fossil spores and pollen of the Jiufotang Formation are sparse in other wells of the Liaohe Basin, this data fill the gap of sporopollen record in the Jiufotang Formation of the Liaohe Basin and play an important role for further understanding of flora nature in Jiufotang deposition age in northern China. In this assemblage, 67.3% belong to gymnospermous pollen which are dominated by Disacciatrileti and Cheirolepidiaceae. They mainly consist of Classopollis,Piceaepollenites,Pinuspollenite, Cedripites,Abietineaepollenites,Protoconiferus. Pteridophytic spores constitute 32.7% of the total grains,mainly including Cicatricosisporites,Concavissimisporites, Ligodiumsporites,Impardecispora, Toroisporis,Klukisporites, Trilobosporites, Maculatisporites, Densoisporites, Hsuisporites, Foraminisporis. Composition of this palynological assemblage shows good agreement with that of the Jiufotang Formation in western Liaoning as well as the 1st Member of the Saihantala Formation of the Erlian Basin in Neimongol.