柴北缘丁叉叉山钛矿床岩石学、矿物学变质演化过程及成矿意义

柴北缘丁叉叉山钛矿床岩石学、矿物学变质演化过程及成矿意义摘要：

柴北缘丁叉叉山钛矿床位于青海省柴达木盆地北缘丁叉叉山区，是其中一种独特的云杉石英脉型钛矿床。本文通过对野外地质调查样品及其薄片进行系统的岩石学、矿物学和地球化学分析，研究了该钛矿床的岩石学、矿物学及变质演化过程，揭示了成矿物质来源及成矿机制。结果表明，该钛矿床岩石主要由石英云母片岩、二辉橄榄岩和辉煌岩组成，主要矿物为磁铁矿和钛铁矿。该地区经历了晚奥陶世、早志留世和早泥盆世三期变质作用的改造，分别形成了白云母-绿泥石、麻粒岩相和青闪石-绿泥石岩相变质带。该钛矿床主要与各变质带中磁铁矿和钛铁矿质大量富集相关，其成矿源区是由海相沉积物经变质作用改造形成的变质岩台地。成矿过程主要是以水热流体为载体的热液活动，早期流体富集了Ti、Cr等金属元素，后期则以Fe、V、Sc为主，形成了此独特的云杉石英脉型钛矿床。研究结果对青海东部地区矿产资源评价和勘查提供了有益的参考。

关键词：丁叉叉山、钛矿床、岩石学、矿物学、变质演化、成矿意义

Abstract:

TheDinchaxishantitanicdepositisoneoftheuniqueYunshanquartzveintypetitaniumdepositsinthenorthernmarginofQinghai-TibetPlateau.Inthispaper,weanalyzedthegeological,mineralogicalandgeochemicalcharacteristicsofthesamplescollectedfromthefieldinvestigationinordertostudytherock,mineralandmetamorphicevolutionofthetitanicdeposit,andrevealthemineralizationmechanismandmaterialsources.Theresultsindicatedthattherocksaremainlycomposedofquartz-micaschist,diabaseanddiorite,containingmagnetiteandtitanomagnetiteasthemainoreminerals.Thestudyareaunderwentthreestagesofmetamorphism,formingmuscovite-chlorite,granuliteandamphiboliticfaciesmetamorphiczonesduringthelateOrdoviciantoearlyDevonian.Themainoremineralsofthetitanicdepositaremagnetiteandtitanomagnetitethataremainlyconcentratedinthemetamorphiczones.Thesourceoftheoredepositisthemetamorphicrockplateauformedbythemetamorphictransformationofmarinesediments.Themineralizationprocessismainlyrelatedtothehydrothermalactivitydrivenbyfluids.EarlyhydrothermalactivityenrichedmetalssuchasTiandCr,whilelateractivitymainlyenrichedFe,V,andSc,formingthisuniqueYunshanquartzveintypetitaniumdeposit.ThestudyprovidesvaluablereferencesfortheevaluationandexplorationofmineralresourcesineasternQinghaiProvince.

Keywords:Dinchaxishan,titanicdeposit,petrology,mineralogy,metamorphicevolution,mineralizationsignificanceTheDinchaxishandepositismainlycomposedoftitanium-bearingquartzveins,whichisauniquetypeofdepositintheYunshanarea.TheoredepositishostedingneissesandmigmatitesofthePrecambriancomplex.Accordingtothepetrologicalandmineralogicalstudies,theore-formingprocessismainlyrelatedtothehydrothermalactivitydrivenbyfluids.

TheearlyhydrothermalactivityenrichedmetalssuchasTiandCr,whilelateractivitymainlyenrichedFe,V,andSc.Thetitanium-bearingquartzveinswereformedbytheprecipitationofhydrothermalfluids,whichwererichinTi,Si,andO.Theprecipitationresultedintheformationofquartzveins,whicharethemajorhostofthetitaniummineralization.

Thepetrologicalandmineralogicalstudiesalsoprovidedinsightsintothemetamorphicevolutionofthegeologicsetting.ThestudiessuggestedthattheDinchaxishandepositislocatedinahigh-grademetamorphiczone.Themetamorphicevolutionoftheregioninvolvedextensiveshearinganddeformation,whichresultedintheformationofmylonitesandultramylonites.Themylonitesandultramylonitesareassociatedwiththemineralizationprocessandplayedacriticalroleintheformationofthetitanium-bearingquartzveins.

ThemineralizationsignificanceoftheDinchaxishandepositissubstantial.Thedepositisrichintitanium,whichisanexceptionallyessentialmetalintheindustry.Thedeposithasthepotentialtobeasignificantsourceoftitaniumforindustrialapplications.ThestudyprovidesvaluablereferencesfortheevaluationandexplorationofmineralresourcesineasternQinghaiProvince.

Inconclusion,theDinchaxishandepositisauniquetypeofdepositintheYunshanarea.ThedepositishostedingneissesandmigmatitesofthePrecambriancomplex.Thepetrologicalandmineralogicalstudiessuggestthattheore-formingprocessismainlyrelatedtohydrothermalactivitydrivenbyfluids.Thedeposithassignificantmineralizationsignificanceandpotentialasasourceofindustrialtitanium.ThestudyprovidesvaluablereferencesfortheevaluationandexplorationofmineralresourcesineasternQinghaiProvinceTheYunshantitaniumdepositisasignificantdiscoveryineasternQinghaiProvinceduetoitsuniquenatureandpotentialasasourceofindustrialtitanium.ThedepositisunusualinthatitishostedinPrecambriancomplexgneissesandmigmatites,whereasmosttitaniumdepositsareassociatedwithyoungerigneousrocks.Thestudyofthedeposithasshedlightontheore-formingprocess,whichappearstobemainlyrelatedtohydrothermalactivitydrivenbyfluids.

Petrologicalandmineralogicalinvestigationsofthedeposithaverevealedthepresenceofvarioustitaniumminerals,includingilmenite,rutile,andtitanite.Themineralsarefoundinamatrixcomposedoffeldspar,quartz,andmica.Microscopicanalysessuggestthattheilmeniteandrutilecoexistedduringtheore-formingprocess,withtheilmeniterepresentinganearlierstageofmineralization.

ThemineralizationoftheYunshandepositisbelievedtoberelatedtohydrothermalfluidsthatmigratedthroughthePrecambrianrocks.Thefluidswerelikelydrivenbymagmaticactivityassociatedwiththetectoniceventsthatshapedtheregion.Thefluidsinteractedwiththerocks,causingalterationandmineralization.Thepresenceofhydrothermalalterationmineralassemblagessuchassericite,chlorite,andalbitesupportsthisinterpretation.

ThestudyoftheYunshandeposithassignificantimplicationsfortheevaluationandexplorationofmineralresourcesineasternQinghaiProvince.ThedepositisthefirstknownoccurrenceofanindustrialtitaniumdepositassociatedwithPrecambrianrocksintheregion,anditsdiscoverymaymeanthatothersimilardepositsexistinthearea.Thedeposit'slocationinanareaofintensetectonicactivitysupportstheideathatmineralizationintheregionmayberelatedtomagmaticandhydrothermalprocesses,whichhavenotbeenwidelyexploredtodate.

Inconclusion,theYunshantitaniumdepositisauniqueandsignificantdiscoveryineasternQinghaiProvince.Thedeposit'shostrocks,mineralogy,andore-formingprocessareunusualcomparedtootherknowntitaniumdeposits.ThestudyofthedepositprovidesvaluableinsightsintothemineralizationprocessesintheregionandmaycontributetothediscoveryofothersimilardepositsFurthermore,theexplorationanddevelopmentoftheYunshantitaniumdepositcouldhavesignificantimplicationsforthelocaleconomy.Withitslargesizeandhigh-gradeore,thedepositcouldpotentiallybecomeamajorproduceroftitaniuminChina.Titaniumisanimportantmetalwidelyusedinvariousindustries,includingaerospace,automotive,andmedical.Theincreasingdemandfortitaniumintheseindustrieshasledtoasteadyriseintheglobalmarketvalueofthemetal.Therefore,thedevelopmentoftheYunshantitaniumdepositcouldnotonlygeneraterevenueforthelocalcommunitybutalsoaddressChina'sgrowingdemandfortitanium,reducingtheneedtoimportthemetal.

However,theexplorationanddevelopmentofthedepositmustbecarefullyplannedandexecutedtominimizetheenvironmentalimpact.Miningactivitiescanpotentiallyposesignificantriskstothesurroundingecosystem,affectingboththefloraandfaunaoftheregion.Thishighlightstheimportanceofsustainableminingpracticesthataimtominimizetheimpactontheenvironmentwhilestillextractingvaluableresources.

Inconclusion,thediscoveryandexplorationoftheYunshantitaniumdepositisasignificantachievementthathasprovidedvaluableinsightsintomineralizationprocessesintheEasternQinghaiProvince.Furtherstudiesarenecessarytofullyunderstandthedeposit'sgeology,mineralogy,andore-formingprocesses.Nevertheless,thedeposit'spotentialasasignificantsourc