皖南歙縣晚中生代基性巖墻群的成因及構(gòu)造意義

皖南歙縣晚中生代基性巖墻群的成因及構(gòu)造意義摘要：

皖南歙縣晚中生代基性巖墻群是華夏地塊南緣晚中生代構(gòu)造演化的重要記錄。本文通過對(duì)巖石組成、構(gòu)造變形、年代學(xué)以及地球化學(xué)特征等方面的研究，揭示了皖南歙縣基性巖墻群的成因及構(gòu)造意義。研究表明，該墻群主要由鎂鐵質(zhì)及輝綠巖組成，形成于晚三疊世至早侏羅世，形成環(huán)境為洋中脊-海山-弧后盆地-陸塊交匯的背景下，并在早白堊世經(jīng)歷了區(qū)域性變質(zhì)作用。晚古生代地層受拉伸作用而形成了一系列斷裂及褶皺構(gòu)造，新生代地質(zhì)作用進(jìn)一步造成了巖石變質(zhì)及逆沖推覆構(gòu)造，這些變形在地殼后碰撞和伸展構(gòu)造階段得到了進(jìn)一步發(fā)展。研究發(fā)現(xiàn)，皖南歙縣基性巖墻群的成因與新華夏洋消減體制造過程有一定的關(guān)系，同時(shí)也表明了該地區(qū)在晚中生代的構(gòu)造演化特點(diǎn)及構(gòu)造轉(zhuǎn)換的變化，具有重要的構(gòu)造地質(zhì)學(xué)研究價(jià)值。

關(guān)鍵詞：晚中生代；基性巖墻群；成因；構(gòu)造意義

Abstract:

TheWallGroupofbasicrockinShexian,SouthernAnhuiProvinceinthelateMiddleAgesisanimportantrecordofthelateMiddleAgestectonicevolutiononthesouthernedgeoftheHuaxiablock.Throughthestudyofrockcomposition,structuraldeformation,chronology,andgeochemicalcharacteristics,thispaperrevealsthegenesisandtectonicsignificanceofthebasicrockwallgroupinShexian,SouthernAnhuiProvince.Thestudyshowsthatthewallgroupmainlyconsistsofultramaficandhornblendegreenstones,whichwereformedinthelateTriassictoearlyJurassicperiod,inthebackgroundoftheintersectionofthemid-oceanridge,seamount,back-arcbasin,andlandmass,andunderwentregionalmetamorphismintheearlyCretaceous.TheLatePaleozoicstrataweresubjectedtotensileforces,resultinginaseriesoffaultandfoldingstructures.Theneotectonicactivityfurthercausedrockmetamorphismandthrust-overthruststructuraldeformation,andthesedeformationswerefurtherdevelopedinthecrustalcollisionandextensionaltectonicstages.StudyshowsthatthegenesisofthebasicwallgroupinShexian,SouthernAnhuiProvincehasacertainrelationshipwiththemanufacturingprocessofthenewHuaxiaOceansubductionsystem,andalsoillustratesthetectonicevolutioncharacteristicsandtransformationoftheareainthelateMiddleAges,havingimportantvalueinthestudyofstructuralgeology.

Keywords:LateMiddleAges;Basicrockwallgroup;Genesis;TectonicsignificancThelateMiddleAgesisacriticalperiodinthehistoryoftheearth'stectonicevolution,markedbysignificantcollisionandextensionaltectonicstages.ThebasicrockwallgroupinShexian,SouthernAnhuiProvince,whichisalarge-scalevolcanic-sedimentaryrockgroup,isanexcellentexampleofthetectonicevolutionofthisperiod.

ResearchhasshownthatthegenesisofthebasicrockwallgroupiscloselyrelatedtothemanufacturingprocessofthenewHuaxiaOceansubductionsystem.DuringthelateMiddleAges,thesubductionofthenewHuaxiaOceanundertheAsianplateledtosignificanttectonicmovementsandtheformationofvariousgeologicalformations,includingthebasicrockwallgroup.

ThebasicrockwallgroupinShexianistheresultofvolcanicactivityduringthelateMiddleAges.Therocksinthegroupcontainalargeamountofbasicmagma,whicheruptedandextrudedontothesurface,formingathicklayerofbasicvolcanicrocks.Later,sedimentaryrockssuchassandstoneandmudstonedepositedontopofthevolcanicrocks,formingasequenceofvolcanic-sedimentaryrocks.

TheformationofthebasicrockwallgroupreflectsthecharacteristicsoftectonicevolutionandtransformationduringthelateMiddleAges.Theareaunderwentaseriesofgeologicalchanges,includingintensevolcanicactivity,sedimentarydeposition,andtectonicmovements.Theoveralltectonicevolutionoftheareawasfromacollisionaltectonicstagetoanextensionaltectonicstage.

Inconclusion,thestudyofthebasicrockwallgroupinShexian,SouthernAnhuiProvince,hassignificanttectonicsignificance.ItprovidesvaluableinsightsintothetectonicevolutionandtransformationoftheareaduringthelateMiddleAges,andhelpsustounderstandthegeologicalprocessesthatshapedtheearth'ssurfaceFurthermore,thestudyalsoshedslightonthelithologicalcharacteristicsandgeologicalstructuresoftheregion,whicharecrucialforunderstandingthedistributionandexplorationofmineralresources.ThebasicrockwallgroupinShexianisknowntocontainmultiplemetallicandnon-metallicmineraldepositsthathaveeconomicsignificance.Forinstance,theregionhasabundantreservesofcopper,iron,lead,zinc,andothermetallicminerals,aswellasnon-metallicmineralssuchaslimestone,dolomite,andquartzite.

Thegeologicalinformationobtainedfromthestudyofthebasicrockwallgroupcanalsobeusedtoassessthegeologicalhazardsintheregion.SouthernAnhuiProvinceisknowntobepronetoearthquakes,landslides,andothergeologicaldisasters,whichcanhavedevastatingeffectsonhumanlivesandproperty.Therefore,acomprehensiveunderstandingofthegeologyandtectonicsoftheareacanhelpinthedevelopmentofappropriatestrategiesfordisasterpreventionandmitigation.

Inconclusion,thestudyofthebasicrockwallgroupinShexian,SouthernAnhuiProvince,isanimportantcontributiontothefieldofgeologyandhassignificantscientific,economic,andsocialimplications.Ithighlightstheimportanceoftheregionintermsofitsrichmineralresources,geologicalhazards,andtectonicevolution.Theresultsofthisstudycanserveasavaluablereferenceforfurtherresearchinthefieldandcanprovideusefulinsightsforgeologicalexploration,mineralresourcedevelopment,anddisasterpreventionandmitigationintheregionFurthermore,thefindingsofthisstudyhavepracticalapplicationsinindustriessuchasmining,oilandgas,andconstruction.Understandingthegeologicalframeworkandmineralizationpatternsoftheregioncanhelpinformexplorationeffortsandfacilitatetheextractionofvaluableresources.Ontheotherhand,knowledgeofpotentialgeologicalhazardssuchasearthquakes,landslides,andvolcaniceruptionscaninforminfrastructureplanninganddisasterresponsestrategies.

Additionally,thisstudyshedslightonthetectonicevolutionoftheregion,whichhasimplicationsforregionalandglobaltectonicmodels.Theidentificationofmajortectoniceventsandtheirtimingcanprovideinsightintothemechanismsbehindtheformationandmovementofcontinents,andcontributetoabetterunderstandingoftheEarth'sdynamicgeologichistory.

Fromasocialperspective,thisstudyhasrelevanceforlocalcommunitiesandpolicymakers.Understandingthegeologicalhazardspresentintheregioncanhelpinformdecision-makingregardinglanduseandzoning,aswellaspreparationandresponsestrategiesfornaturaldisasters.Moreover,theidentificationofmineralresourcescanhaveeconomicbenefitsforlocalcommunitiesthroughjobcreationandincreasedinvestment.

Inconclusion,thecontributionofVinceetal.tothefieldofgeologyhassignificantscientific,economic,andsocialimplications.Thestudyhighlightstheimportanceoftheregionintermsofitsmineralresources,geologicalhazards,andtectonicevolution,andprovidespracticalapplicationsforindustriesandpolicymakers.