海拉尔盆地贝尔凹陷贝27井早白垩世孢粉组合及其地质意义  

EARLY CRETACEOUS SPOROPOLLEN ASSEMBLAGES OF WELL BEI 27 FROM THE DAMOGUAIHE FORMATION IN THE BUIR SAG,HAILAR BASIN,INNER MONGOLIA,CHINA AND THEIR GEOLOGICAL SIGNIFICANCE

作　　者：韩刚[1] 张文婧[2] 薛云飞[2] HAN Gang;ZHANG Wenjing;XUE Yunfei(College of Earth Sciences, Northeast Petroleum University ,Daqing 163318;E rploration and Development Research Institute of Daqing Oil fleld Company Limited, Daqing 163712)

机构地区：[1]东北石油大学地球科学学院,大庆163318 [2]大庆油田有限责任公司勘探开发研究院,大庆163712

出　　处：《微体古生物学报》2018年第1期74-89,共16页Acta Micropalaeontologica Sinica

基　　金：国家自然科学基金项目(白云岩对陆相湖盆泥页岩层系储层物性和脆性的影响定量研究;批准号:41672113)资助~~

摘　　要：内蒙古自治区呼伦贝尔盟地区海拉尔盆地贝尔凹陷贝27井早白垩世孢粉植物群自下而上划分为3个孢粉组合:克鲁克孢(Klukisporites sp.)-原始松柏粉(Protoconiferus sp.)-双束松粉(Pinuspollenites sp.)组合,分布于南屯组二段;小桫椤孢(Cyathidites minor)-多云云杉粉(Piceaepollenites multigrumus)-单束松粉(Abietineaepollenites sp.)组合,分布于大磨拐河组一段;无突肋纹孢(Cicatricosisporites sp.)-卵形光面单缝孢(Laevigatosporites ovatus)\|破隙杉粉(Taxodiaceaepollenites hiatus)组合,分布于大磨拐河组二段。上述孢粉组合证明,贝27井南屯组地质时代为早白垩世Berriasian—Valanginian期;大磨拐河组地质时代应该为早中白垩世(Valanginian—Hauterivian)期,尽管未见到最原始的被子植物花粉(如Clavatipollenites和Asteropollis等),但具有一定百分含量的Triporoletes reticulatus(0-4.76%)出现,也不排除部分进入Barremian期的可能。贝27井南屯组二段沉积时期植被主要由针叶林构成,属于湿润的温带气候。大磨拐河组一段沉积时期植被主要由针叶林\|草丛构成,属于湿润的北亚热带气候。大磨拐河组二段沉积时期植被类型以针阔叶混交林\|草丛为主,属于湿润的北亚热带气候。From bottom to top,early Cretaceous palynological assemblages of Well Bei 27 in the Buir depression,Hailar Basin,Hulun Buir City,Inner Mongolia,China can be subdivided into 3 sporopollen assemblages.The Klukisporites sp.-Protoconiferus sp.-Pinuspollenites sp.assemblage is distributed in the second member of the Nantun Formation;Cyathidites minor-Piceaepollenites multigrumus-Abietineaepollenites sp.assemblage is distributed in the first member of the Damoguaihe Formation;Cicatricosisporites sp.-Laevigatosporites ovatus-Taxodiaceaepollenites hiatus assemblage is distributed in the second member of the Damoguaihe Formation.These sporopollen assemblages demonstrate that the geologic age of Well Bei 27,Nantun Formation belongs to Early Cretaceous Berriasian—Valanginian age,while the Damoguaihe Formation is Early Cretaceous Valanginian—Hauterivian age.Althouth no primal angiosperm pollens,such as Clavatipollenites and Asteropollis was found,is also possible some Triporoletes reticulatus（0-4.76%）appears,a Barremian age for thd Damoguaihe Formation.Vegetation of Well Bei 27 during the sedimentary period of the second member of the Nantun Formation mainly composed of coniferous forest,belonging to a humid temperate climate.Vegetation during the sedimentary period of the first member of the Damoguaihe Formation mainly composed of coniferous forest-grass,suggesting a humid north subtropical climate.Vegetation the sedimentary period of the second member of the Damoguaihe Formation mainly composed of coniferous and broad-leaved mixed forest-grass,also indicating a humid north subtropical climate.

关 键 词：孢粉组合 早白垩世 古气候 贝尔凹陷 南屯组 大磨拐河组 海拉尔盆地 内蒙古自治区 

分 类 号：P618.1[天文地球—矿床学]