Metamorphic petrology and geology in China:A review

(整期优先)网络出版时间:2018-01-11
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ThedevelopmentofmetamorphicpetrologytometamorphicgeologyinChinahasalonghistory.AncientbasementmetamorphicrocksaredistributedprimarilyintheNorthChinaCraton,theYangtzeBlockandTarimCraton.Theyaremainlymadeupofplutonicgneissandmetamorphosedsupercrustrock,transformedtogranulitefaciesthroughArcheanPaleoproterozoic.ManyofthePaleoproterozoicmetamorphicrockshaveundergonehigh-pressuregranulitefaciesmetamorphismwithaclockwisemetamorphicevolutionpath.Theultrahightemperature(UHT)granulitesfromtheLatePaleoproterozoicarefoundinNorthChinaCraton.Manyhigh-precisionchronologicaldatahaveallowedpreliminaryconstructionoftheformationandevolutionaryframeworkofdifferentmetamorphicbasements.Primarilytherearelow-temperatureandhigh-pressureblueschist,high-temperatureandhigh-pressuregranuliteandultrahigh-pressure(UHP)eclogitefaciesmetamorphicrocksinthePhanerozoicorogenicbelt.ThediscoveryofeclogiteintheSuluorogenandalargequantityofcoesiteinitscountryrocksshowthattherewasadeepsubductionofvoluminouscontinentalmaterialsduringthecollisionprocessbetweentheYangtzeblockandtheNorthChinaCratonintheEarlyMesozoicphase.Fromthestudiesof,forinstance,organicmattervitrinitereflectance,illitecrystallinity,illite(muscovite)polytypeandillite(muscovite)bdimension,theLatePaleozoicstrataintheeasternregionofInnerMongoliaandthenorth-centralregionofNEChinahaveonlyexperienceddiagenesistoanextremelylow-grademetamorphism.Thediscoveryofimpact-metamorphosedrocksinXiuyanareaofLiaoningprovincehasenrichedthetypeandcategoryofmetamorphicrocksinChina.Thephaseequilibriummethodhasbeenwidelyusedinthestudyofmetamorphismofmiddleandhigh-grademetamorphicrocks.Onthebasisofexistinggeologicsurveysandmonographicstudyresults,differentscholarshaverespectivelycompiled1:1500000MetamorphicGeologicalMapandSpecificationsofQinghaiTibetPla