山东汶宁地区石炭—二叠系高分辨率层序划分及聚煤规律分析-high resolution sequence division and coal accumulation law analysis of carboniferous - permian in weining area, shandong province.docx

摘要运用高分辨率层序地层学理论和方法，充分收集和整理钻孔岩心、测井曲线资料，对汶宁煤田的石炭—二叠系含煤地层进行了系统的成因相组合分析和沉积体系划分。研究表明石炭—二叠系可划分为四个沉积体系：潮坪沉积体系、障壁—泻湖沉积体系、河控浅水三角洲沉积体系和河流—湖泊复合沉积体系。重点进行了高分辨率层序界面的识别和对比、高分辨率层序地层划分和内部单元构成分析、基准面旋回识别和对比。在汶宁煤田石炭—二叠系含煤地层中共识别出短周期旋回、中周期旋回和长周期旋回三种。共划分出了4个长周期旋回，9个中周期旋回以及多个短周期旋回。在基准面旋回变化基础上分析总结了汶宁煤田的煤聚集规律：泥炭沼泽的形成与分布受控于基准面变化，不同级次基准面旋回的叠加控制了煤的聚积规律；成煤作用出现在基准面旋回的一定位置上，泥炭沼泽的持续发育需要可容纳空间与沉积物补偿之间的平衡，即当沉积物补给通量变化导致的A/S比值趋于1时，是成煤的有利时期。此外，通过对古植物、古气候、古地理和古构造的基础上研究了汶宁地区的控煤因素。关键词：汶宁地区石炭—二叠系高分辨率层序地层基准面聚煤规律ABSTRACTByutilizingtheprincipleandmethodofthehigh-resolutionsequencestratigraphyandfullycollectingcoreandwellloginformation,thispapersystemmaticalyanalyzesgeneticfaciesanddividesthedepositionalsystemofCarboniferous-Permiancoal-bearingstratainWenshang-Ningyangcoalfield.ItsuggeststhatCarboniferous-Permiancanbedividedintofourdepositionalsystem:tidalflatdepositionalsystem,barrier-lagoondepositionalsystem,fluvial-dominatedshallowwaterdeltaicdepositionalsystem,fluvial-lacustrinedepositionalsystem.Theemphasisofthispaperistoidentify,contrastanddividethehigh-resolutionsequenceinterface,analyzetheconstitutionofitsinternalunits,identifyandcontrastthebaselevelcycle.TherearethreekindsofcyclesinCarboniferous-Permiancoal-bearingstrataofWenshang-Ningyangcoalfield,namelyshort-periodcycle(several),middle-periodcycle(nine)andlong-periodcycle(four).OnthebasisofchangesofbaselevelcyclethelawofcoalaccumulationinWenshang-Ningyangcoalfieldcanbeanalyzedandconcluded:theforminganddistributioniscontrolledbychangesofbaselevelandthebaselevelsuperimpositionofdifferentrankscontrolsthelawofcoalaccumulation;incoalationappearsonthecertainpositionofbaselevelcycleandtheconsistentdevelopmentofpeatswampneedstheequilibriumbetweenadmissiblespaceandsedimentcompensation.Thatistosayit’sthebestperiodofbecomingcoalwhenA/Cratiothatiscausedbythefluxchangesofsedimentcompensationiscloseto1.Besides,itstudiesthefactorsthatcancontrolcoalonthebasisofstudyingfossilplant,paleoclimate,paleogeographyandpaleostructure.Keywords:AreaofWenshang-Ningyang,Carbonifer