简介：Theresultsof118REEanalysesofLi-FgranitesfromSouthChinaandothercountriesindicatethattherearethreevariationtypesofREEpatterncurveswithdifferentevolutiontrendsfromearlytolatestagesofLi-FgranitecomplexoffromlowertoupperpetrofaciesoftheLi-Fgranitebody;(1)thedecreasing,(2)theincreasing,and(3)thesaltatoryvariationtypes.Thefirstvariationtypeiscalledthepositiveevolutiontype,attributedtocrystallizationdifferentiation.Thesecondiscalledthereversionevolutiontype.whichrepresentsliquidsegreationdominatedbyvapor-liquiddistillation.Thethirdiscalledthesaltatoryvariationtype,whichisformedfromliquidsegregationdominatedbyimmiscibilty,Therefore,theindicaticesofliquidsegregationdominatedbyimmiscibilityarethesaltatoryvariationtypeofREEpatternevolutionandtheseparationofthemainevolutiontrendlineseitherfromthesub-evolutiontrendlinesorfromthecompositionpointsofLi-FgranitesinthediagramsofREE-(La-Yb)NandLa/Sm-La,Theindicatricesofliquidsegregationdominatedbyvapor-liquidfractionaldistillationarethereverstionevolutiontypeofREEpatterncurvesandthemainevolutiontrendlinesofLi-Fgranitesdirectingtotheupperright-handontheREE-La/Yb)NandLa/Sm-Ladiagrams.

简介：Li-Fgranitesallovertheworldcanberepresentedbythreeendmembers,i.e.,theNa-richongonite(O),theK-richxianghualingite(X)andtheSi-richtopazite(T),Charactersandcriteriaarepresentedfortheseend-mnemberrocks,VerticalzoninginLi-Fgranites,asreflectedbyincreasingnormativeQandC(corundum)anddecreasingALK(K2O+Na2O)withincreasingcontentoffluorine,canbeexplainedusingthethree-end-memberschemeintermsofpetrochemistryandnorms.Consideringthedifferenceinmeltstructure,visocosityanddensitybetweentheendmembers,incouplewiththeregulartiesthatgoverntheNa-KandSiALKsegregationknownfromfieldevidenceandexperiments,itissuggestedthatthethreeendmembersmayhaveresultedfromliquidsegregation(immiscibility)ratherthanfromcrystalfractionationascommonlybelieved.

简介：通过国内外花岗岩体的412对角闪石-黑云母40Ar-39Ar年龄（tAr）与锆石U-Pb年龄（tZr）之间差值ΔtZr-Ar（tZr-tAr）进行的频数统计分析表明：ΔtZr-Ar呈对称正态分布（偏度系数CSK==-0.276,峰度系数CKU=16.52）;ΔtZr-Ar既呈正值又有负值,其众数值为0.70Ma,均值为1.15Ma。采用最小二乘法计算,花岗岩体锆石U-Pb年龄与花岗岩角闪石-黑云母40Ar-39Ar年龄拟合出相关系数很高（R=0.996）,回归系数接近l的线性回归方程（tAr=1.00453×tZr-1.932）。这些统计特征表明花岗岩角闪石-黑云母40Ar-39Ar定年测定结果与锆石U-Pb定年测定结果在允许的误差范围内是一致的,不存在花岗岩锆石U-Pb年龄〉角闪石40Ar-39Ar年龄〉黑云母40Ar-39Ar年龄的规律。结合Dodson＇s矿物封闭温度计算公式中存在问题的剖析,本文得出结论,按Dodson＇s公式计算得出的花岗岩矿物40Ar-39Ar封闭温度不能代表从花岗岩浆晶出造岩矿物40Ar-39Ar体系的封闭温度。