煤沉積過程成煤構(gòu)造環(huán)境中英文對照外文翻譯文獻(xiàn)

中英文對照外文翻譯中英文對照外文翻譯Coal-ProducingTectonicEnvironmentsThisfinalchapterintheinvestigationofcoalsedimentationisconcernedwithdepositionalaspectsofthehighestorderofmagnitude,namely,theinfluenceofthecrustalsettingonpeataccumulation.Thisisabroadandcomplexfieldwhichdrawsoninformation,gatheredfrommanydifferentdisciplinesoftheearthsciences.Someofthesearecurrentlyevolvingquiterapidly,whileothersreina“moppingup”stage,insensuKuhn(1970)andWalker(1973),followingrecentscientificrevolutions.Anexampleofthelatteristhereplacementofthegeosynclinalhypothesisintheearly1970sbytheconceptofplatetectonics.Evenafteralifespanof20years,thisnewparadigmisstillintheprocessofbeingrefinedandfittedoutwithconceptualsubsets,asshownbythecurrentemphasisonterraneanalysis.Itisthereforenotpossibleatthisstagetomakeadefinitivestatementonthechosensubject,butmerelytooutlinetheprincipleonwhichamoderngeotectonicclassificationofcoalfieldscanbeestablished.Eventhismodestgoalisfraughtwithdifficulty,becausethechangefromthepredominantlystaticgeosynclinalviewofglobaltectonicstoitsmodern,largelymobilisticinterpretationhascomplicatedthetectonicclassificationofsomecoalfields.Whilethetectonicstatusofmanycoalfields,e.g.thoseinforedeepsorforelandbasinshaschangedrelativelylittle,thesettingofcoalsfoundininter-andintramontanetroughs,i.e.withinorogeniccordilleras,cannotbeproperlyassessedwithoutverycarefulstudy.Accordingtothegeosynclinalconcept,practicallyalloftheseintradeeps,togetherwithfore-andbackdeeps,theirextra-orogeniccounterparts,wereregardedaspartofagroupofmolassesbasins,thedevelopmentofwhichaccompaniesorfollows“terminalgeosynclinaltecto-orrgenic”(Aubouin1965).Thisfixistandstrictlysequentialinterpretation(highlightedbytheterm“epieugeosyncline”ofKay1951)hasnoplaceinmoderngeotectonicanalysis,whichviewsmostorogenicbeltsascollagesofautochthonousandallochthonousterranes,i.e.astectono-stratigraphicassemblageswithpossiblycoevalbutheterogeneousstratigraphicrecordsreflectingtheiroriginindifferentgeologicalandgeographicaldomains(MongerandPrice1979,Mongeretal.1982).Thetectonicsetting,whichinfluencedtheformationofanallochthonousterraneassemblagebeforeaccretion,mayhavebeenverydifferentinstyleandphysicallyfarremovedfromitsrestingplaceafterdocking.Itfollowsthatamulti-terraneorogenmaycontainavarietyofcoalsformedatdifferenttimesbeforeandafterterraneaccretion.Moreover,contemporaneouspre-accretionarycoaldepositsformedindifferentterranesarelikelytovaryincoaltypes,coalificationhistoriesandtectonicstyles,andallofthesewillinturndifferfromthepost-accretionarymolassescoals,whichalonereflecttheconditionaprevailingintheorogenitself.Indeed,thesituationmayevenbemorecomplex,aswillbediscussedinChap..Platetectonicshascreateditsownnomenclature,ofwhichonlytheessentialtermswillbeusedhere.Theywillbesupplementedbytermswhichareeitherdescriptive,andthereforeindependentofgeotectonictheory,orwhichhavestoodthetestoftimebecausetheyareusefulinspiteoftheirgenericassociationwithnowobsoleteconcepts.Forexample,theexpressions“mio-”and“eugeosynclinalassemblage”havebeenkepthereasreferencetermforshallowwatermarine(mainlyshelf),andoceanfloorpelagite,turbiditeandophioliteassociationa,respectively.Moreover,reducedtoa“miogeocline”,themiogeosynclinehasintheNorth-Americanliteraturebecomeastandardtermforautochthonous,sedimentaryterracewedgesonlappingcontinentalmargins.Alsotectonicattributesofsediments,suchas“synorogenic”flyschand“l(fā)atesyn-(folded)topostorogenic(non-folded)”molasses,respectively,canstillbeusedinaplatetectoniccontextwithoutundulycorruptingtheirrelativelyloosedefinitions.Particularlyinthediscussionofcoalfieldssituatednearconvergentplateedges,theconceptofmolassesastheproductofthedestructionoftheupliftedorogenisveryuseful.Asinthepreviousdiscussion,itisnotthepurposeofthischaptertogivedetaileddescriptionsofalargenumberofcasesbuttoselectafewtypicalexamplesofcoalfieldsandrelatetheessenceoftheirarchitecturetotheirrespectiveplatetectonicsettings.1EarlyExamplesofaTectonicClassificationofCoalfieldsLarge-scalecoalformationcantakeplaceonlyinactivelysubsidingregions,forexampleinsedimentarybasins.Itispossiblethereforetocharacterisethegeotectonicenvironmentoccupiedbyacoalmeasuresequenceinamannersimilartothatwhichisappliedtoothersedimentaryenvironments.Stutzer(1920)andStille(1926)wereamongthefirsttorecognisethegeneticlinksbetweentectonismandtheformationofcoal.Stille,inparticular,referredtothestrikingdifferenceintermsofbasinfill,numberofcoalseamspresent,theiraveragethicknessandproportioninrelationtototalcoalmeasurethickness,whichexistbetweentheCarboniferousandTertiarycoalmeasuresofEurope.HeattributedsuchdissimilaritiestocontrastingdegreesofcrustalmobilityintheareasaffectedbythetwomainEuropeancoal-formingperiods.HisresultsaresummarizedinTable9.1.EvenifdifferencesincompactionratiosbetweentheTertiarybrownandCarboniferousbituminouscoalsaretakenintoaccount(toalesserdegreethecompactionappliestointer-seamsediments)thecontrastisquiteremarkable.LateritwasshownbyvonBubnoff(1937)thatthedistributionoftheworldreservesofcoalisalsorelatedtothegeotectonicsettingofcoalfields.HisconclusionsaresummarizedinTable9.2,whichindicatesthatofallcoaldepositsknownupto1937,some71%developedinformertectonicallyveryactiveenvironments,particularlyinthemolassesforedeepswhichdevelopadjacenttoorogenicbeltsandreceivemuchoftheweathereddebriswasheddownfromtheuplands.CarboniferouscoalmeasuresinmobileVaricanbasinsTertiarycoalmeasuresincratonicbasinsofCentralEuropeAveragecoalmeasurethickness3000m150mAveragenumberofcoalseams2002Averageseamthickness1m15mCumulativethicknessofcoal180m25mProportionoftotalcoal6%16.7%Proportionofeconomicinsitucoal3.6%12%Table9.1.Stille’s(1926)comparison(slightlymodified)betweensomecharacteristicsofcoalmeasuresformedintectonicallymobileandcratonisedpartsofEurope,respectivelyTable9.2.Thedistributionofworldreservesofcoalinreferencetothegeotectonicsettingofcoalfields.(AftervonBubnoff1937)Foredeepsmarginaltoorogenicbelts70%Intradeepswithinorogenicbelts1%Shelfbasinsoncratonicmargins21%Cratonicinterior8%Theconcentrationofcoalintheregionsassociatedwithorogenicbeltsisevenmorehighlightedwhenthelateralextentofthedepositsisconsidered.Coalfieldssituatedwithinorontheshelfmarginsofcratonscoverawiderareathanthecomparativelynarrowforedeeps,butitsarealrestrictioniscompensatedbythefrequencyofcoalseamsoccurringinathickstackofcoalmeasures.Aswillbediscussedlater,thisisrelatedtothesubstantialandprolongedsubsidencethatthecontinentalmarginissubjectedtonearasubductioncomplex,asanorogenicbeltisaccretedontotheplateedge.Itisnotsurprising,therefore,thatvonBubnoff(1937)foundalsoaclosetemporalrelationshipbetweenorogeniesandcoalformationinNorthAmerica,Europe,AsiaandSouthernContinents.Ofcourse,therearemajororogeniesknownwhicharenotassociatedwithcoaldeposits.However,invariably,theirabsenceisrelatedtofactorsaffectingthevegetablesource.Forexample,allpre-Devonianorogeniesoccurredatatimewhentheplantkingdomwasstillinsufficientlyequippedbyevolutiontofulfilitsroleasaneffectiveproducerofpeat.Thecontinentalshelfenvironment,beinglessmobile,hasproducedfewercoaldepositsthantheorogenicdomain.Inthiscontextitisimportanttodefinethetermshelf.Tothegeographer,theshelfregionisusuallythatpartoftheseawhichextendsbetweenthestrand-lineandthecontinentalslope.However,asvonBubnoff(1948a)noted,thepositionofthestrandlineisquiteincidentaldependingoncrustalmovementsandrelativesealevelpositions.Fromthegeologicalviewpoint,itappearsthereforeusefultoextendthedefinitionoftheshelfsothatthetimefactorcanbeaccommodated.Shelfregionsmaythenberegardedasthosemarginalbutfuullyintegratedzonesofcontinentswhichareoccasionallyaffectedbyshallowmarinetransgressions.Typicalareasarethetrailingedgesofcontinentalplatesandthecratonicmarginsofforedeeps.Commonlytwotypesofshelfenvironmentsaredistinguished,calledstableandunstable,respectively(vonBubnoff1948a;KrumbeinandSloss1963).Themajorityfortheirassociatedcoalfieldsisparalicincharacter,whichishighlightedbytheintercalationofcoalmeasureswithmarinestrata,afeaturethatisalsocommontothemolassesforedeeps.However,marinestratamaynotalwaysberecognizedbecauseoflackoffossils,whichisrelatedtothedilutionofseawaterbyanexcessiveinfluxoffreshwaterfromthenearbycoastalswamps(DuffandWalton1962).Intracratoniccoalfieldsandthoseformedinintramontancbasinsarefrequentlylimnicincharacter,i.e.theyhavenohydrologicalconnectiontothesea,becausetheyhavebeenformedinland-lockedbasinsabovethethenprevailingsealevel.AspectacularmodernexampleofintramontanepeatformationoccursinthereedmarshesontheshoresofLakeTiticaca,3810mabovesealevelintheSouthAmericanAndes.Comparedwiththeirparaliccounterpartslimniccoalfieldshavesmallsizeandunstablepositionabovedepositionalbaselevel.However,asindicatedabove,thetermintradeepmaycoveracomplexarrayofdepositionalenvironments,someofwhichmaybetotallyunrelatedtotheorogeninwhichtheynowoccur.ThelastgroupofcoalfieldsmentionedinTable9.2occursintheinteriorofcontinentalareas.Theyowetheirexistencetoavarietyofeventsincludingepeirogenicsaggingofcontinentalcrustandcontinentalrifting.Manypeatandcoaldepositsformedonconsolidatedbasementhavenotectonicoriginatall,butaretheresultofpaludificationrelatedtodifferentialsubsidence.Examplesaresubsidenceduetosaltmigrationandleachinginthesubsurface,ortheformationofsinksisolatedcoalfieldsaretheresultoftheterrestrialisationoflakes.Mostofthesecoalfieldsarelimnic,butraremarineincursionsmayhaveoccurredduringtheirdevelopment.Thetectonicsettingofacoalfieldexertsastronginfluenceonthetypeofcoalthatisformedwithinitsboundaries.Hacquebardetal.(1967),Mackowsky(1968),ShibaokaandSmyth(1975),Hunt(1982)andothershavedemonstratedthatcoalcompositionvariesmoreinlargeparalicdepositsthaninlimnicsetting,becauseofthelargervarietyoffactorsinfluencingextensivecontinentalshelforforedeepenvironments.Moreover,coalsformedinrapidlysubsidingforelandbasinsaremorelikelytohavehighvitrite,clariteandashcontentsthancoalsformedoncratonicshelvesorinslowlysubsidingcratonicbasins.Thesecoalsarelikelytoberichindullcoalsconsistingmainlyofduriteinertite.2BasinFormationasPartofPlateTectonicsThetheoryofplatetectonics,althoughprimarilyconcernedwithhorizontalmovementsoftherelativelyrigidlithosphericplates(crustanduppermostmantle)overthesofterasthenosphere(mantle),hasalsoprovidedanexplanationfortheverticalmovementsthatleadtosubsidenceandbasinformation.Thefollowingcrustalmovementscanbedistinguished(afterDickinson1974andFischer1975):Changeincrustalthickness.Accordingtotheprincipleofisostasythicklow-densitycontinentalcrustfloatshigheronheavymantlematerialthanthinhigh-densityoceaniccrust.Forexample,anisostaticallycompensatedcontinentalcrustof50kmthicknessextends4kmabovethesea,whereasa6-km-thinoceaniccrustiscoveredbyapproximately5kmofwater(Holmes,1965).Platetectonicsprovidesseveralmechanismsforbothcrustalthickeningandthinning.Thelatter,whichisofimmediateinteresthere,isoftenexemplifiedinareasofcontinentalrifting,whereintheearlystagesofplateseparationthecrustalongtheriftzoneisattenuatedbyextensionalstep-faulting,thusformingrapidlysubsidinggrabensandhalf-grabens.Erosionalthiningofanisostaticallyupliftedcrustalportionsalsoleadstosubsequentsubsidence.Upliftduetocrustalthickeningisofsomeinterestinthiscontext,becauseitcreatespotentialsourceareasforcoalmeasuresediments.Thisisparticularlyimportantinforedeeps,wherebasinformationisinvariablycoupledwithupliftinnearbyorogenicbelts.Mostexamplesofupliftduetocrustalthickeningarerelatedeithertotheinjectionofmagmaintothecrustortocontinentalcollision.Changeinthermalregime.Convectioncurrentsintheplasticasthenosphereareresponsiblenotonlyforhorizontalplatemovementsbutalsoforsomeverticalcrustalmotionswhichareindependentofceustalthickness.Upwellingmagmafromthemantlemaycauseupliftbyformingheatbulgesintheoverlyingcrust,andnewoceaniccrustisformedwheresuchmantlematerialisextrudedalongmid-oceanicriftzones.Thelatterareelevatedabovetheseafloorbecauseofthermalexpansionoftheaffectedcrustwhichbecomescolderanddenserwithincreasingageanddistancefiomtherisecrest.Areasofthermaltumescencewithinoralongthemarginofcontinentalplatesaresubjectedtoerosionalthinning,whichaccentuatestheirsubsidenceduringtheperiodofthermaldecay.Loadingaffects.Whensedimentsaccumulateonanisostaticallycompensatedcrusttheadditionalloadwillcreateadisequilibriumwhichwillbebalancedbysubsidence.Thismeansthat,whatevertheinitialcauseforthecreationofadepositionalsite,oncesedimentsarebeginningtoaccumulate,theirweightandcompactionareinsomemeasureresponsibleforthedepositionofadditionalsediments.This,tosomeextentself-prepetuatingprocessisparticularlywellshownbytheflexuralbendingunderloadofthecontinentalshelfmargin(Walcott1972).Othercommongeotectonicsitesforload-inducedsubsidenceandsedimentationareorogenicfordeepmarginswhichareflexurallydown-warpedundertheweightoftheoverridingthrustsheetsgeneratedintheadjacentfoldbelt(Price1973;Laubscher1978;Beaumont1981;QuinlanandBeaumont1984).Additionalloadingofthedownwardlyflexedcrustisprovidedbythemassofmolassessedimentsproducedinthefoldbeltandtransportedintothedevelopingforedeep.Ashasbeendiscussedbefore,additionalcausesofsedimentandcoalformationareprovidedbysubsurfacesaltmigrationandleaching,andeustaticsea-levelchanges,inparticularbytheirinteractionwithcrustalmovements,whichproduceavarietyofsedimentaryresponsesindifferenttectonicdomains.Forexample,riftingofoceaniccrusthasdepositionalconsequencesquitedifferentfromtheseparationofcontinentalcrust.Theriftingofcontinentalcrustmayleadtocoalformation,buttheriftingofoceaniccrustisunlikelytoleadtotheformationofcoal.AsurveyoftheeffectsofthegeotectonicsettingofcoalfieldsonpeataccumulationandcoalcompositionrequiresthereforeanunderstandingofthemajorcrustalelementsofEarthandtheirprincipalmotions.Aplate-tectonicinterpretationofthemaincrustalelementsinreferencetotheirabilitytoprovidesuitablesitesfortheformationofcoalissummarizedinFig.9.1.Thisinterpretationisbasedonthenotionthatthecreationofnewlithosphericcrustalongmid-oceanicriftsandthelateralmovementofthelithosphericslabstowardssubductionzones,whereoceaniccrustisconsumed,producethreetypesofplatejunctures.Theseare(afterDickinson1974):1.Divergentplateedges,whereplateseparationtakesplaceandthedevelopinggapisfilledbyupwellingmantlematerialweldingnewoceaniccrusttotheseparatingplates.2.Convergentplateedges,whereoldcrustissubductedintothemantleunderneaththeleadingedgeoftheoverridingplate.3.Transformplateedges,whereadjacentplatesarelaterallydisplacebymovementalongstrike-slipfaults.Fig.9.1.ThegeotectonicsettingofcoalfieldsinreferencetoCurray’s(1975)plate-tectonicsubdivisionsoftheearth.Theidentificationofcountriesisbyinternationalcountrycode.ThetectonicsubdivisionsofcoalfieldsusedbyvonBubnoff(1937)inTable9.2canbebroadlyaccommodatedwithintheplatetectonicframeworkofFig.9.1.Thefore-andmanyintradeepsarepartofplateconvergencecomplexes,whichinviewoftheiroverwhelmingquantitative,i.e.economicimportance,willbediscussedfirst.Themidplatecontinentalmarginisthesettingofshelfdeposits,whereasthecratonicandriftvalleysettingsrefertotheinteriorofconsolidatedareas.3CoalfieldsSituatedNearConvergentPlateEdgesTherelationshipsbetweentectonicsettingandcoalcontentofaregioninferredfromTables9.1and9.2suggestthatcoalcanformmorefrequentlyingeologicalenvironmentscapableofofferingalargernumberandvarietyofcrustalmovementsperunittimethanlessmobileareas.Asmentionedabove,thisisareatureofforedeeps,whichhavebeenprolificcoalproducersinthepat.Mountainchainsconsistingoffoldedandoftenmetamorphosedrocksareformedaslinearandoftenarcuateweltsalongtheedgesofconvergingplatesbyanumberoftectonicandmagmaticevents,allofwhichappeartobeprimarilyrelatedtotheprocessofsubduction.However,notallformersubductionzoneshaveledtotheformationofcoalfields,whichisaproblemrelatedtothenatureoftheconvergingplates,i.e.whethertheyconsistofoceanicorcontinentalcrust.AccordingtoFigs.9.1and9.2,therearethreescenarios:Subductionofoceaniccrustbeneatnoceaniccrust(Fig.9.2A).Itisunlikelythatthissituationwillleadtosignificantcoalfieldformationbecauseoftheconsiderablewatercoveroftheseafloor.Oceaniccrustemergesabovewateronlywhereithasbeenthickenedbymagmaticinjectionandmaythenproduceisolatedsmallcoaloccurrences.However,aslongasonlyoceaniccrustisinvolved,thelackofastrongnearbysedimentsourceleavestheadjacentoceanbasinstarvedandtoodeepforpeataccumulation.Conversely,compositearcsystems,inwhichseveralsubductionzonesareoperatingsimultaneouslyinoppositedirectionsand/orinwhichallochthonouscrustalfragments(terranes)havebeenaccretedtothearcsystem,mayprovidesuitableconditionsforcoalformation.AnexamplearetheJapaneseislands,whichcontaincoalfieldsofTertiaryageinbothfore-andbackarcpositions(Aihara1986).Forearcbasinselsewherearenotknowntobesignificantcoalproducersduetothetectonicinstabilityduringthebasinstageandthesubsequentdestructionbytectonism.Theoccurrenceofa3000-m-thickPalaeogenesuccessionoffoldedandfaultedcoalmeasuresintheHidakaBasinofcentralHokkaido,describedbyAihara(1986),isthereforeacomparativelyrarecaseofathickcoalmeasuresequenceformedandpreservedinaforearcsetting.Subductionofoceaniccrustunderneathcontinentalcrust(Fig.9.2B).Thereareseveralpastandpresentexamplesofextensivecoalformationassociatedwiththistypeofplateconvergence.Themaincoalfieldsformedintheprocessoccupyretroarcbasins(Dickinson1974)filledwiththicksedimentarysuccessions.Thebeginningofsedimentationisprobablyrelatedtoextensionaltectonicsinthebackarcarea,atatimewhensubductionisstillinprocess.However,duringandfollowingtheaccretionofallochthonousterranestheretroarcbasinissubjectedtoacompressionalstressregimewhichcausesittosubsideundertheweightofoverridingthrustwedges.Partialsubductionofcontinentalcrustbeneathcontinentalcrust(Fig.9.2C).Thistyperepresentsanexampleofcontinentalcollision.Becauseofitsthicknessandlowdensity,continentalcrustcanonlypartiallybesubductedwhichleadstotectonicstackingandoverlapofthetwoplatemargins.Theconditionsofcoalformationsinaretroarcbasinarethesameasin(2)fortheoverridingplate.Inaddition,atleasttwolociofpotentialpeataccumulationarecontributedbytheconsumedplate,one(usuallydestroyedbysubsequentorogenesisandmetamorphism)intheformofthecontinentalshelfmarginwhichwasformedbeforecollisionoccurred,andtheotherintheformofaperipheralbasin(Dickinson1974)formedatthefootofthecollisionbelt.Retroarcandperipheralbasinssharethesamebasicforedeeparchitecture(Beaumont1981),becausebotharetheproductsofflexuraldownwarpingoftheunderlyingcrustfollowingloadingbyoverridingthruetsheets.Fig.9.2A-C.Threepossibilitiesofplateconvergence.Continentalcrust;ocaniccrust;volcanics;???molassessediments;???marinesediments中文：成煤構(gòu)造環(huán)境在已知的煤沉積過程中，這種最終階段是與影響泥炭堆積外在的呈最高狀態(tài)的重要的沉積因素相聯(lián)系的。這是一個(gè)寬廣且復(fù)雜的領(lǐng)域，它吸收了聚集地球科學(xué)許多不同學(xué)科的知識。一部分領(lǐng)域已經(jīng)相當(dāng)迅速的普遍展開，而其他的一些在跟隨最近的科學(xué)革命處于一個(gè)結(jié)束期。在20世紀(jì)70年代早期的地槽假說被板塊構(gòu)造理論所替代就是后者中的一個(gè)例子。即使在經(jīng)過20年后，這種新的模式仍處于被改進(jìn)或裝備于概念的子集，同時(shí)在地形分析中被列為通用的重點(diǎn)的過程中。因此，在這個(gè)時(shí)期對于被選擇的題目做一個(gè)決定性的陳述是不可能的，但是，只是描述關(guān)于現(xiàn)代大地構(gòu)造因素方面的煤田分類是可以建立的。這種現(xiàn)代化目標(biāo)的實(shí)現(xiàn)是充滿困難的，因?yàn)橐獜恼純?yōu)勢的全球構(gòu)造學(xué)靜止地槽的觀點(diǎn)變?yōu)楝F(xiàn)代的，大量的活動(dòng)論解釋使得一些煤田的構(gòu)造分類變得復(fù)雜。當(dāng)許多煤田的構(gòu)造情況，例如那些前淵或陸前盆地已經(jīng)相對改變一點(diǎn)，建立在內(nèi)部或山間的槽即造山的山脈上的煤田裝置，如果沒有仔細(xì)的學(xué)習(xí)是不能被適當(dāng)?shù)姆峙上氯?。根?jù)該地槽的概念，幾乎所有的這些內(nèi)淵，連同前淵和后淵，他們的超級造山帶對口，被視為一組穩(wěn)定地塊的一部分，其中伴隨著“有機(jī)終端地槽構(gòu)造”的發(fā)展（Aubouin1965）。這固定的并嚴(yán)格層序的解釋（Kay所強(qiáng)調(diào)的“后成優(yōu)地槽”1951）并沒有發(fā)生在現(xiàn)代大地構(gòu)造分析中，其中的大部分造山帶被作為拼貼的本地成因和異地成因的地形，即作為構(gòu)造地層組合與可能同時(shí)代不均勻的地層記錄，反映其原產(chǎn)地在不同的地質(zhì)上或地理上的領(lǐng)域（MongerandPrice1979,Mongeretal.1982）。構(gòu)造環(huán)境，這也影響到形成一個(gè)異地巖層組合前的堆積，在遠(yuǎn)離了物源地沉積下來后，在類型和形態(tài)上可能已經(jīng)非常不同。它如下一個(gè)多造山帶的巖層可能含有各種煤形成于不同時(shí)期之前和之后的巖層的堆積。此外，當(dāng)代加積前形成的煤炭儲量在不同的地形很可能會有所不同，在煤的類型，煤化歷史和構(gòu)造樣式，所有這些將在來自不同加積后的穩(wěn)定地塊煤盆地，其中僅反映在造山帶本身?xiàng)l件普遍存在。事實(shí)上，情況甚至可能會更加復(fù)雜，將在chap.討論。板塊構(gòu)造已創(chuàng)造了自己的名稱，其中只有基本術(shù)語將被用于在這里。他們對輔助術(shù)語有的只是描述性的，因此獨(dú)立的大地構(gòu)造理論中，有的經(jīng)受了時(shí)間的考驗(yàn)，因?yàn)樗麄冊谕ㄓ玫亩F(xiàn)在已經(jīng)過時(shí)的概念中是有用的。舉例來說，詞“中新世”和“優(yōu)地槽組合”一直在用，涉及到淺海（主要是大陸架），和深海結(jié)核，濁積巖和蛇綠巖套，分別作為參考。此外，提到“冒地向斜”，冒地槽已在北美文獻(xiàn)中成為一個(gè)標(biāo)準(zhǔn)的原地術(shù)語，沉積階地邊緣超覆了大陸邊緣。同樣沉積物的構(gòu)造特征，如“同造山期的”復(fù)理石和“后期的同褶皺到造山期（沒有褶皺作用)”的穩(wěn)定地塊，分別地，仍然可以用在一個(gè)板塊構(gòu)造背景下，沒有不必要的混淆他們的相對精確的定義。尤其是在討論煤田位于聚合的板塊邊緣，穩(wěn)定地塊的概念用在造成破壞該隆起造山帶是十分有益的。由于在先前的討論，也不是本章的目的給予詳細(xì)說明了一大批例子，但要選擇幾個(gè)典型的涉及了本質(zhì)和結(jié)構(gòu)的煤田，以各自的板塊構(gòu)造建立。1一個(gè)早期的煤田構(gòu)造分類的例子大型煤田的形成可以發(fā)生的地方，只有在活躍的下陷地區(qū)，例如在沉積盆地。因此，用一個(gè)煤系序列表征大地構(gòu)造環(huán)境的方式表示其他適用的沉積環(huán)境是有可能的。Stutzer(1920)和Stille(1926)第一次確認(rèn)構(gòu)造與成煤之間的成因關(guān)系。Stille，尤其是提到突出差異而言，歐洲盆地充填中煤層的平均厚度和的比例關(guān)系與總煤系厚度的聯(lián)系，在這之間存在的石炭紀(jì)和第三紀(jì)煤的數(shù)量。他歸因于這樣的相似性，以對比程度的地殼的流動(dòng)性，在歐洲的兩個(gè)主要成煤期受影響地區(qū)。他的結(jié)果總結(jié)在表9.1.中。即使在第三系褐色和石炭系瀝青煤壓實(shí)比率之間的不同的計(jì)算（在較小程度壓實(shí)適用于跨煤層沉積物）的對比是相當(dāng)顯著的。后來結(jié)果表明，由vonBubnoff(1937)表示，分布世界各地的煤的儲量是與煤田的大地構(gòu)造環(huán)境有關(guān)的。他的結(jié)論的摘要列于表9.2，這表明在1937年所有的煤炭儲量都已經(jīng)知道，約71％的是發(fā)展構(gòu)造非常活躍的環(huán)境，特別是在穩(wěn)定地塊盆地前淵發(fā)展來的，其中毗鄰造山帶和從高地來的接收的許多風(fēng)化碎片。表9.1.Stille’s（1926）一些比較（略作修改）石炭系的煤在移動(dòng)的Varican盆地中的數(shù)量第三系的煤在歐洲中部克拉通盆地中的數(shù)量平均煤系厚度3000m150m平均煤層數(shù)量2002平均煤層厚度1m15m累積煤層厚度180m25m產(chǎn)出煤占總量比例6%16.7%煤占經(jīng)濟(jì)比例3.6%12%分述在構(gòu)造移動(dòng)盆地和歐洲部分克拉通盆地特征煤的數(shù)量表9.2.分布在世界儲備煤中提到了大地構(gòu)造環(huán)境的煤田。（vonBubnoff1937之后）前淵邊際到造山帶70%內(nèi)淵造山帶內(nèi)1%在克拉通盆地邊緣的陸架盆地21%克拉通盆地內(nèi)部8%側(cè)向范圍的沉積被認(rèn)為在與造山帶相關(guān)的地區(qū)的煤的聚集中更是突出的。煤田位于沙洲的邊緣或沙洲內(nèi)古陸核的涵蓋了更廣闊的領(lǐng)域較相對狹窄的前淵，但其地域的限制，是補(bǔ)償?shù)念l率煤層發(fā)生在一個(gè)一定數(shù)量厚的煤層。正如我們將在所后面討論的，這是涉及到大量的和長期沉陷的被認(rèn)為在大陸邊緣受到附近俯沖的復(fù)雜的，作為一個(gè)造山帶是與板塊邊緣共生的。這是不足為奇的，因此,在北美，歐洲，亞洲和南部大陸vonBubnoff(1937)還發(fā)現(xiàn)一個(gè)山脈與成煤之間的相近關(guān)系。當(dāng)然，那兒已知的山脈與煤的沉積是沒有關(guān)系的。但是，往往他們的缺失是與影響植物來源有關(guān)的。例如，所有的前泥盆紀(jì)造山帶發(fā)生的時(shí)候,植物界仍然不能滿足作為生產(chǎn)泥炭的作用。大陸架的環(huán)境，缺少移動(dòng)性，比造山作用產(chǎn)生的煤炭沉積少。在這方面是定義大陸架這個(gè)術(shù)語是很重要的。對于地理學(xué)來說，大陸架地區(qū)向海的部分通常在股線和大陸斜坡之間延伸。不過，由于vonBubnoff(1948a)指出，濱線的位置是相當(dāng)偶然的，決定于地殼運(yùn)動(dòng)和海平面位置.從地質(zhì)的角度來看，大陸架定義的擴(kuò)大似乎是有用的，因此時(shí)間的因素可以忽略。大陸架地區(qū)可能被視為邊緣的那些地區(qū)，但大陸的完整區(qū)域是偶爾受淺海的超覆。典型的地區(qū)是在大陸邊緣的尾端，大陸板塊和克拉通邊緣的前淵。常見的兩種類型是大陸架是顯著的環(huán)境，分別為所謂的穩(wěn)定和不穩(wěn)定(vonBubnoff1948a;KrumbeinandSloss1963)。多數(shù)與它們相關(guān)的煤田是近海特征，這是所強(qiáng)調(diào)的插層煤在海相地層中的數(shù)量，其中一個(gè)特征是穩(wěn)定地塊盆地前淵普遍存在的。不過，因?yàn)槿鄙倩?海相地層不一定一直得到承認(rèn)，這是與過量的新鮮水從沿海沼澤大量涌入有關(guān)的(DuffandWalton1962)。克拉通內(nèi)的煤田和那些形成于山間盆地的煤田在特征上經(jīng)常是湖泊相的，即它們對于海洋來說沒有水文學(xué)的意義，因?yàn)樗麄冊诤髞淼暮Ｆ矫嬷弦呀?jīng)形成堵塞的內(nèi)陸盆地。一個(gè)引人注目的現(xiàn)代的例子，山脈之間內(nèi)泥炭的形成是發(fā)生在南美安第斯山脈高于海平面3810米蘆葦沼澤對海岸的的湖。與他們相比，在沉積基底的水平面之上近海成因的相對湖泊成因煤田有規(guī)模小和不穩(wěn)定的特征。然而，如上文所示，術(shù)語內(nèi)淵可能包括一個(gè)復(fù)雜系列的沉積環(huán)境，其中一些可能會與造山帶現(xiàn)在發(fā)生的完全無關(guān)。最后一批在表9.2提到的煤田發(fā)生在內(nèi)部的大陸地區(qū)。他們應(yīng)該歸功于各種各樣的活動(dòng)，包括造陸下陷大陸地殼和大陸裂谷。許多泥炭和煤炭沉積的形成是基于沒有構(gòu)造的起源在所有，但泥炭化的結(jié)果是與不同的沉降有關(guān)的。這些例子是由于沉積物在地下遷移和過濾后沉淀，或下沉的孤立煤田的形成是由于該陸表的湖泊。大部分的這些煤田是湖泊相的，但罕見的海侵可能發(fā)生在他們的發(fā)展過程中。在形成其邊界過程中,煤田的構(gòu)造環(huán)境有著重要的影響力。Hacquebard等(1967),Mackowsky(1968),ShibaokaandSmyth(1975),Hunt(1982)和其他人已經(jīng)表明，煤的組成在很大程度上近海相比湖泊相呈現(xiàn)更大的不同，因?yàn)榇罅康牟煌蛩赜绊憣拸V的大陸架或前淵盆地環(huán)境。此外，煤的形成在迅速下沉前陸盆地更可能有高含量的微鏡煤，微亮煤和灰分比煤形成的穩(wěn)定的邊緣上，或在慢慢下沉克拉通盆地。這些煤很可能是豐富的暗煤為主的微惰性煤。2盆地形成作為板塊構(gòu)造理論的一部分