四川盆地西部栖霞组热液白云岩中的自生非碳酸盐矿物Word文档格式.docx

四川盆地西部栖霞组热液白云岩中的自生非碳酸盐矿物Word文档格式.docx

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栖霞组；

热液蚀变；

萤石；

氟磷灰石；

重晶石；

有机质强迫成熟；

黏土矿物的强迫热演化

AuthigenicnoncarbonatemineralsinhydrothermaldolomiteofMiddlePermianQixiaFormationinthewestofSichuanBasin,China

HUANGSi-jing,LIXiao-ning,HUANGKe-ke,LANYe-fang,LÜ

Jie,WANGChun-mei

StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,Chengdu610059,China

Abstract:

Thehydrothermalenvironmentisanimportantdiageneticenvironment.MVTleadandzincoredepositsandsomedolomitereservoirsarerelatedtohydrothermalenvironments.Basedonthinsectionexamination,scanningelectronmicroscopyandtheenergydispersionX-rayanalysis,someauthigenicnoncarbonateminerals,includingillite,fluorite,fluorapatite,quartz,bariteandpyrite,andpyrobitumenareidentifiedintheMiddlePermianQixiaFormationonthewestofSichuanBasin.Thesemineralsoccurintheintercrystalline/intragranularporesanddissolutionporesindolomiteswithdifferenttextures,especiallyinthedissolutionporesofnonplanar-saddledolomite.Fluidinclusionhomogenizationtemperaturesofhostdolomitesmainlyrangefrom80℃to180℃,upto240℃orhigher.TheoccurrenceofauthigenicmineralstakingCa2+asthecation,suchasfluorite,fluorapatiteandalsocalciteinthedissolutionspaceofdolomite,revealsthatthefalloftemperatureafterthehydrothermaldolomiteprecipitationcausesthechangeoffluidnatureanddissolutionofdolomite.Thehydrothermalalternationalsoleadstotheformationofilliteowingtoforcedthermalevolutionofclayminerals.Pyrobitumenexistingbetweendolomitecrystalsrepresentstheforcedmaturationandovermaturationoforganicmatterduetohydrothermalalternation.ThehydrothermalalternationofcarbonaterocksfromQixiaFormationinthewestofSichuanBasinoccurredduringDongwuMovementabout259MaB.P.（thelatestageofMiddlePermian）,associatedwiththethermaleventsrelatedtotheEmeishanbasalteruptionwithpaleoheatflowuptoorhigherthan60~80mW/m2anddurationtimeofabout6Ma.TheburieddepthofthedolomitestratainQixiaFormationwaslessthan500metersatthatperiod,sotheprocessofhydrothermalalterationhadnothingtodowithgeothermalgradientfunction.VariousauthigenicmineralsandpyrobitumenformedbyabnormalthermalevolutionoforganicmatterinthedolomitestrataprovideevidencesforthehydrothermalenvironmentdiagenesisexperiencedbycarbonatesfromQixiaFormationinthewestofSichuanBasin.

Keywords:

westofSichuanBasin;

QixiaFormation;

hydrothermalalternation;

fluorite;

fluorapatite;

barite;

forcedmaturationoforganicmatter;

forcedthermalevolutionofclayminerals

下刚果盆地A区块下白垩统Albian阶沉积层序与古地理演化

于水1文华国2郝立华1郝立业1程涛1郑荣才2

（1.中海石油研究中心，北京100049；

2.油气藏地质及开发工程国家重点实验室（成都理工大学），成都610059）

［摘要］通过对西非被动大陆边缘下刚果盆地中的A区块沉积相和层序地层分析，确定Albian阶主要为一套具“间断-交叉”混积机理的碳酸盐岩混杂陆源砂、泥沉积，可划分出5个三级层序，经历了从混积缓坡→周缘混积台地→破裂混积台地→深水混积陆棚→深海盆地（深水扇）的沉积演化全过程，对应于威尔逊构造旋回中后裂谷拗陷阶段向大陆漂移的过渡阶段，其中发育主力储、产层的SQ2-SQ3层序为Ⅱ型周缘混积-破裂台地沉积层序，可进一步划分为TST和HST两个体系域。

解析了混积碳酸盐岩层序地层与沉积充填响应特征，建立了研究区混积碳酸盐岩“滑脱-盐拱-转换”多因素联控的沉积演化模式，提出SQ3层序时期的盐拱构造顶部呈帚状分布和垂向偏转加积发育的破裂混积台缘浅滩为最有利的储集微相类型；

以TST和HST体系域作为编图单元，编制了SQ2和SQ3层序各体系域的岩相古地理图并探讨了有利储集相带展布规律，认为A区块Albian阶SQ2-HST、SQ3-TST和SQ3-HST三个体系域中预测出的叠置台缘浅滩，应成为今后的勘探重点。

［关键词］沉积-层序；

混积碳酸盐岩；

浅滩；

沉积演化模式；

层序-岩相古地理；

Albian阶；

下刚果盆地

SedimentarysequenceandpaleogeographicevolutionofAlbianStage,LowerCretaceousinBlockAofLowerCongoBasin

YUShui1,WENHua-guo2,HAOLi-hua1,HAOLi-ye1,CHENGTao1,ZHENGRong-cai2

1.PetroleumResearchCenterofCNOOC,Beijing100049,China；

2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,Chengdu610059,China

LowerCongoBasinislocatedonthepassivecontinentalmarginofWestAfrica.ThispaperstudiesthesedimentaryfaciesandsequencestratigraphyofBlockA,ascertainsthatAlbianisasetofcarbonaterocksmixedwithterrigenoussandandmudforminginamixedmechanismof“intermittence-cross”diamicticprocess.Albiancanbedividedintofivethird-ordersequencesinthearea.Thewholesedimentaryandevolutionaryprocessofthestratahasundergonethesedimentaryramp→peripheraldiamicticplatform→fractureddiamicticplatform→deep-waterdiamicticcontinentalshelf→deepseabasin（deep-waterfan）,correspondingtothetransformationphaseoftheWilsonstructuralcyclefromback-arcriftdepressiontocontinentaldrift.SQ2andSQ3sequences,themainreservoirs,areTypeIIsedimentarysequencesofperipheraldiamictic-fracturedplatformandeachsequencecanbefurtherdividedintoTSTandHSTsystemstracts.Theresponsecharacteristicsofsedimentarysequencesandsedimentaryfillingofmixedsiliciclastic-carbonaterockareanalyzed.Thesedimentaryevolutionmodelofthegangcontrolofmultiplefactorsincluding“slippage,saltarchandconversion”isestablished.Besides,attheSQ3sequencestage,thefracturedanddiamicticplatformedgeshoalwithabroom-likedistributionandthedevelopmentofverticalaccretiononthetopofthesaltarchstructurewillbethemostfavorablemicrofaciesinthearea.BytakingTSTandHSTsystemstractsasthetwomappingunits,theauthorsdrawalithofaciespaleographicmapofeachsystemtracts,discussthedistributionofthefavorablereservoirfacies,andthenmakeapredictionaboutAlbianinBlockA.FinallytheauthorsthinkthatthesuperimposedplatformedgeshoalfaciesintheSQ2-HST,SQ3-TSTandSQ3-HSTsystemtractsshouldbethekeyareasinthefutureexploration.

sedimentarysequence;

mixedsiliciclastic-carbonaterock;

shoal;

sedimentaryevolutionmodel;

sequence-lithofaciespaleogeography;

Albian;

LowerCongoBasin

黑龙江金厂金矿花岗斑岩锆石地球化学、U-Pb年代学及地质意义

钱烨1孙丰月1李碧乐1陈静2第五春荣3

（1.吉林大学地球科学学院，长春130061;

2.青海省地质矿产研究所，西宁810012；

3.西北大学大陆动力学国家重点实验室，西安710069）

［摘要］为确定与金厂金矿成矿有关的岩浆类型、活动时限和构造背景，采用LA-ICP-MS技术对研究区花岗斑岩开展了锆石U-Pb年龄及原位微区微量元素测定。

结果表明：

锆石环带发育，wTh/wU值>

0.4，具有岩浆锆石特征；

锆石年龄分布于220Ma和103~123Ma2个区间，代表了2期岩浆事件；

对2种锆石分别命名为捕获岩浆锆石和新生岩浆锆石；

锆石的地球化学和年龄信息显示捕获岩浆锆石的原岩为早三叠世花岗岩；

锆石微量元素信息暗示花岗斑岩是早三叠世花岗岩高度熔融结晶分异、侵位于浅部氧化环境而形成，这一过程导致新生岩浆锆石负Eu异常程度降低。

新生锆石加权平均年龄为（113.5±

3.8）Ma，与成矿年龄一致，据此认为早白垩世的岩浆事件是金厂金矿成矿事件的直接原因，成矿背景为太平洋板块俯冲后的岩石圈伸展。

［关键词］锆石地球化学；

锆石U-Pb年代学；

岩浆锆石；

地质意义；

金厂金矿

GeochemistryandU-PbgeochronyofzirconfromgraniteporphyryofJinchanggolddepositinHeilongjiang,Chinaanditsgeologicalsignificance

QIANYe1,SUNFeng-yue1,LIBi-le1,CHENJin2,DIWUChun-rong3

1.CollegeofEarthSciences,JilinUniversity,Changchun130061,China;

2.InstituteofGeologyandMineralResourcesofQinghaiProvince,Xining810012,China;

3.StateKeyLaboratoryofContinentalDynamics,NorthwestUniversity，Xi`an710069,China

TheJinchanggolddeposit,locatedintheeastsegmentoftheCentralAsianorogenicbelt,isalargehydrothermaldepositassociatedwiththeMesozoicmagmaticactivities.Inordertodeterminethetype,ageandtectonicsettingofthemetallogenicmagmaticrock,theauthorsmeasuretheU-Pbdatingandinsitutraceelementsofthezirconsfromgraniticporphyrybycathodoluminescence（CL）imagesandLA-ICP-MS.AllzircongrainshavefineoscillatoryzoningsinCLimages,andtheratioofTh/Uis>

0.4,indicatingtheirmagmaticorigin.ZirconU-Pbdatingis220Maand103~123Ma,representingthetwo-phasemagmaticevents.Thezirconwithageof220Mabelongstothecapturedmagmaticzircon.Correspondingly,zirconswithagesof103~123Maarederivedfromthenewmagma.GeochemistryandU-PbdatingofthezirconssuggestthatthecapturedzirconwasderivedfromtheEarlyTriassicgraniteporphyry.ThetraceelementsofthezirconsindicatethatthegraniteporphyryoriginatedfromthehighlymeltingandcrystallizationdifferentiationandtheemplacingintheoxidizingenvironmentintheshallowcrustoftheEarlyTriassicgranite.ThevaluesofnegativeEuanomaliesinzirconsfromthenewmagmadecreasedintheoxidizingenvironment.TheweightedaverageU-Pbage（113.5±

3.8Ma）ofzirconsfromnewmagmaisidenticalwiththemetallogenicage.Therefore,theEarlyCretaceousmagmaticeventdirectlyresultedinthegoldmineralizationintheJinchangdeposit.ThemineralizationoccurredinlithosphericextensionalsettingrelatedtothesubductionofthePacificPlate.

zircongeochemistry;

zirconU-Pbgeochronology;

magmaticzircon;

geologicalsignificance;

Jinchanggolddeposit

赣西萍乐凹陷带卡林型金矿的构造控矿特征

杨斌1董国臣2莫宣学2曾书明3

（1.成都地质矿产研究所，成都610083；

2.中国地质大学地球科学与资源学院，北京100083；

3.江西地勘局赣西地质调查大队，南昌330201）

［摘要］探寻赣西萍乐凹陷带卡林型金矿的成矿流体来源和主要控矿因素。

通过对区内2个典型的卡林型金矿点（吴村和大石芴）的野外地质调查以及成矿期包裹体H、O同位素研究，表明2个矿区的成矿流体主要组成自西向东表现出了从岩浆水到大气降水过渡的特征，而成矿热液的来源是岩浆水。

通过研究赣西地区的区域构造背景、区内卡林型金矿的含矿地层、控矿断裂和矿体的产状以及岩石渗滤性与构造的关系，表明构造是区内卡林型金矿的主要控矿因素，构造控矿的主要表现形式为褶皱与翼部层间滑动的组合控矿，金矿体以层状、似层状赋存在层间滑动面中。

［关键词］萍乐凹陷带；

卡林型金矿；

成矿流体来源；

构造控矿；

赣西

Tectonicandore-controllingcharacteristicsoftheCarlingolddepositsinthePingledepressionofJiangxi,China

YANGBin1,DONGGuo-chen2,MOXuan-xue2,ZENGShu-ming3

1.ChengduInstituteofGeologyandMineralResources,Chengdu610083,China;

2.ChinaUniversityofGeosciences,Beijing100083,China;

3.GanxiGeologicalSurveyofJiangxiBureauofGeologyandMineralExploration