优秀毕业设计毕业论文资源勘探萍乐拗陷带；微细浸染型金矿

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1、毕业论文学院：姓名：专业：学号:指导教师:萍斥拗陷带西段具备微细浸染型金矿床成矿的大地构造条件。断裂破碎带和沉积间断界面控制矿床的产出。成矿作用主要受控于地层岩性和构造类型。岩浆直接参与成矿作用的特点不明显，相对较重要的一个因素应该是有一个低温持续活动含矿流体的作用。最佳化探指示元素组合为Au+As+Hg+Sbo该区金矿源于中元古界基底地层，特别是宜丰组为重要的矿源层，海西期形成地层假整合面，燕山期构造作用导致区域上出现小型褶皱、层间断裂构造等。此外，燕山期区内部分地区冇过渡同熔型岩浆岩侵入或冇幔源型岩浆侵入。在岩浆分

2、异演化过程屮，形成了富含S、C(h等挥发份的岩浆热液，它与大气降水混合，在深部岩浆热源、深部地温热源及构造地温热源等综合热动力的驱动下，发生对流循环，萃取矿源层中的金等成矿元素形成混合含矿热液，在渗滤循环过程中，最后沿上述有利构造组合处发生充填交代作用，最终形成卡林型金矿化及矿体。在喜马拉雅期的表生氧化作用下，特别是在红土化作用下，形成了卡林型金矿床的氧化带。关键词：萍乐拗陷带；微细浸染型金矿；成矿规律ABSTRACTThewesternpartofPingledepressionzonesisbelievedtobe

3、astructurallyfavorableregionfortheformationoffinedisseminatedgolddeposits.Hiatusandfracturedzonecontrolthemineralizationoccurrences,whichdirectlyleadtomostorebodiesintheformsofstrata-andstructure-bounded.ThereisnodirectevidenceofMagmatism-originatedmineralizatio

4、nintheregion?butmagmatismmightstillplaysomerolesforAumineralizationthroughprovidingheat-sourcethatcanacceleratethecirculationofAu-bearinghydrothermalsolutions.Accordingtogeochemicalsurvey,thebestindicatorforAumineralizationintheregionistheanomalyofAu-As-Hg-Sbele

5、mentalassemblage.ThesourceofgoldisproposedtobefromtheMiddleProterozoicbasement,especiallytheYifengFormation.Tectonically,regionalcrustupliftinHercynianresultedinlargescaleunconformityintheregion;Yanshanianmovementisdominantlyalateralmovement,whichledtotheformati

6、onoffoldsandfaultsintheregion.Acompanyingtotheformationoffaultsandfolds,mantle-derivedorsyntacticmagmaintrusionsoccurred.MagmaticintrusionanddifferentiationbroughtalotofvolatilecomponentssuchasS,CO2andothers.Thesevolatilecomponents,bymixingwithdownwardmovingprec

7、ipitation,formedhydrothermalsolutions.Withthedrivingforcesfromthemagmaticheat,thesemixedsolutionbegantocirculatealongdifferentkindsofstructuressuchasveinsandrockfractures.Atthemeantime,thesolutionswoulddissolvegoldandsomeothermetalelementsfromitshostrocks.Whengo

8、ld-bearingsolutionbecamesaturatedorarrivedatsomegeochemicalandphysicalbarriers,goldandothermetalswouldprecipitateandaccumulate,andultimatelyformstheCarlin-typegoldore