华北克拉通孔兹岩带中段大青山—乌拉山变质杂岩立甲子基性麻粒岩年代学及地球化学研究.pdf

《华北克拉通孔兹岩带中段大青山—乌拉山变质杂岩立甲子基性麻粒岩年代学及地球化学研究.pdf》由会员上传分享，免费在线阅读，更多相关内容在行业资料-天天文库。

1、1000-0569／2013／029(02、-0462—84ActaPetrologicaSinica岩石学报华北克拉通孔兹岩带中段大青山一乌拉山变质杂岩立甲子基性麻粒岩年代学及地球化学研究刘平华刘福来蔡佳刘建辉施建荣王舫LIUPingHua，UUFuLai，CAIJia，ⅡUJianHui，SHIJianR0ngandWANGFang中国地质科学院地质研究所，北京100037InstituteofGeology，ChineseAcademyofGeologicalSciences，Beijing100037，China20124)9—18收稿．201

2、34)14)7改回．LiuPH。LiuFL。CalJ，LiuJH，ShiJRandWangF．2013．GeochronologicalandgeochemicalstudyoftheLijiazimaficgranulitesfromtheDaqingshan-Wulashanmetamorphiccomplex，thecentralKhondaliteBeltintheNorthChinaCraton．ActaPetrologicaSinica，29(2)：462—484AbstractTheLijiazimaficgranulitesarepre

3、dominantlycomposedofAmpCpx—Opxgranulite，Grt—bearingAmpCpx-OpxgranuliteandBtAmpCpx．Opxgranulite，andhavebeenfoundasirregularlensesanddeformeddykeswithintheA1一richgneissesandgraniticgneissesintheDaqingshan—Wulashanmetamorphiccomplex．Theapparent2~7Pb／Pbagesrecordedbythemetamorphiczi

4、rcondomainswiththemiddle．tolow．pressuregranulite—faciesmineralinclusionsofCpx+Amp+P1．whichareconsistenttothematrix—typemetamorphicassemblagesofthemaficgranulites．rangefrom1933±39Mato1834±40Mawithaweightedmeanageof1892-i-7Ma，whichareinterpretedasthetimingofthemiddle,-tolow-pressu

5、regranulite—faciesmetamorphismofthemaficgranulites．Mobileelementssuchasthelargeionlithophileelements(K，Na，Sr，Rb)ofthemaficgranuliteschangedinsignificantlevels，hi【ghfieldstrengthelements(suchasNb，Zr，Ti)andrareearthelementsbasicallyunchangedandkeepstableduringthemetamorphicprocess

6、．TheLijiazimaficgranulitesfromtheDaqingshancomplexbelongtotholeiitie—basalticrockseries，withtheconcentrationsofSiO2at45．58％～51．4O％．andMgvaluemainlyrangingfrom41to54．Thecompositionoftherareearthelementsofthemaficgranulitesischaracterizedbytheflat，(La／Yb)cN=1．30～1．51)withnoEuanoma

7、lies(Eu／Eu=0．93～1．04)onthechondfite—normalizedpatterns．AllsamplesofthemaficgranulitesshareobviousnegativeanomalyinNb，ZrandTiofthePhanerozoicislandarcbasahs．AccordingtothegeochemicalandgeochronologicaldataoftheUjiazimaficgranulites，itissuggestedthattheprotolithagesoftheLijiazimaf

8、icgranulitesis2450～1930Ma，theprotolithsofthemaf