辽宁北部秀水盆地秀D1井孢粉组合及其地层意义

摘要

This paper discusses the sporo-pollen fossils collected from Xiu D1 well in Xiushui basin,northern Liaoning Province.Analysis,identification and systematic studies show that sporo-pollen from the depth 62.1～1089.7 m in Xiu D1 well can be divided into 3 assemblages.The upper assemblage (at the depth of 62.1～339m) is represented by genus Cicatricosisporites-lmpardecispora-Pinuspollenites,and its geological age is early Cretaceous Valanginian-Hauterivian.The middle assemblage (381.5～699.3m) is represented by genus Densoisporites-Cicatricosisporites-Piceaepollenites,and its geological age is Early Cretaceous Berriassian.The lower assemblage (703.85～1089.7m) is represented by genus Osmundacidites-Klukisporites-Podocarpidites,and its geological age is Late Jurassic Tithonian.The characteristics of 3 sporo-pollen assemblages can be compared with features of formations with sporo-pollen-containing assemblages,such as the Dabeigou Formation in the northern area of Hebei Province,the Lower Cretaceous Yixian Formation and the Jiufotang Formation in the western area of Liaoning Province,and the Lower Cretaceous Huoshiling Formation as well as the Shahezi Formation on the southeastern margin of the Songliao Basin.The determination of stratigraphic age of sporo-pollen-containing assemblages is very important,which solves the stratigraphic division of column well and the correlation between stratigraphic column wells and regional strata.In addition,it provides detailed basic information for the study of regional stratigraphic paleontology.%孢粉化石采自辽宁省北部秀水盆地的秀D1井,分析、鉴定和系统研究结果表明,来自秀D1井井深62.1～1089.7m的孢粉化石自下而上划分为3个孢粉组合,下部孢粉组合(井深703.85～1089.7m)以Osmundacidites-Klukisporites-Podocarpidites为代表,地质时代为晚侏罗世堤塘期(Tithonian),中部孢粉组合(井深381.5～699.3m)以Densoisporites-Cicatricosisporites-Piceaepollenites为代表,地质时代为早白垩世贝里阿斯期(Bemassian),上部孢粉组合(井深62.1～339m)以Cicatricosisporites-lmpardecispora-Pinuspollenites为代表,地质时代为早白垩世凡兰吟期—欧特里夫期(Valanginian-Hauterivian).秀D1井钻遇地层所含孢粉组合特征在区域上可以与冀北地区大北沟组,辽宁西部地区下白垩统义县组、九佛堂组,松辽盆地东南缘下白垩统火石岭组、沙河子组所产的孢粉组合对比.含孢粉组合地层时代的确定解决了井柱地层的划分,以及与区域地层的对比关系,同时为区域地层古生物研究提供了翔实的基础资料.