摘要
TheearlyMesozoicgranodiorites(ca.165Ma)inthenortheasternHunanProvince(NEH)haveSiO2=65.4-69.65%,K2O/Na2O=0.95-1.38andK2O+Na2O＞6%,A/CNK=0.96-1.13andbelongtometaluminoushigh-Kcalc-alkalineseries.TheyarecharacterizedbyLREEandLILEsenrichment,andHFSEdepletionwithslightlynegativeEuanomalies(Eu/Eu*=0.62-0.90).Theinitial87Sr/86Srratiosareinrangefrom0.711458to0.717461,andεNdvaluesvaryfrom-9.4to-12.3,distinctfromthoseofthecontemporaneousgranodioritesmantle-derivedfromtheSoutheasternHunanProvince(SEH)(87Sr/86Sr(i)=0.707962～0.710396,εNd(t)=-6.98～-2.30).Bycontrast,suchsignaturesareroughlysimilartothoseoftheneighboringotherMesozoicgraniticplutons(Eu/Eu*=0.30-0.70;87Sr/86Sr＞0.710;εNd=-12to-16)inSouthChinaBlock(SCB),whichhavebeeninterpretedastheremeltingproductsofPrecambrianbasement.TheProterozoiclower-middlecrustisanimportantcontributortothepetrogenesisoftheseearlyMesozoicgranodioritesintheNEH.AnintracontinentalextensionsettingispresentinthenortheasternHunanProvinceatthattimeduetothedemandofenoughthermaltransfer.
出版日期
2005年01月11日（中国期刊网平台首次上网日期，不代表论文的发表时间）
