微量元素地球化学中国地质大学5微量元素数据利用和地球化学解释.pptx

,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,#,微量地球化学,Trace Element Geochemistry,“,Geochemistry really is for everyone!,”,By Fersman(1958),5.,微量元素数据的利用和地球化学解释,有用的参考书,H.Rollinson,“,Using geochemical data,”(Longman,London,1993),F.Albarde,“,Introduction to geochemical modelling,”,&,“,Geochemistry,”,M.Wilson,“,Igneous petrology,a global tectonic approach,”,5.2.,微量元素数据分析,?,?,?,?,?,?,5.2.,微量元素数据分析,数据质量评价,数据分析原理,数据分析的常规方法,数据分析实例,有用的软件,数据的获得,与已知样品进行对比,y=0.8627x+0.3289,R,2,=0.9998,0,10,20,30,40,50,60,0,20,40,60,80,元素,i,测定值,),元素,i,理论值,标准样品,未知样品,数据质量评价,？,？,？,？,实际样品监控,国际标准物质，如,BHVO-2,、,BCR-2,、,G-2,、,GSR-1,、,GSR-3,、,AGV-1,、,1640,等等。,实验室内部标准,重复样品,空白样品,对实际数据的了解（如,REE,）,数据质量评价指标,相对误差（,RE,）,标准偏差（,SD,）,相对标准偏差（,RSD,）,内部精度,外部精度,检出限,（方法检出限和仪器检出限）,国际标准物质,实验室内部标准,重复样品,（分析样品或标准物质）,空白样品,(,全流程空白和仪器噪音,),中国地质大学,(,武汉,),地质过程与矿产资源国家重点实验室,LA-ICP-MS,室,Agilent7500a,GeoLas 2005,-10,-5,0,5,10,R,E,(,%,),Be,Sc,V,Cr,Co,Ni,Cu,Zn,Ga,Rb,Sr,Y,Zr,Nb,Cs,Ba,La,Ce,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Ho,Er,Tm,Yb,Lu,Hf,Ta,Tl,Th,U,AGV-2,BCR-2,BHVO-2,GSR-3,问题,某厂家给定其产品玻璃棒中,Cu,含量为,5ppm,，,Pb,含量为,5ppm,，他们所用的仪器为,ICP-AES,。请问该数据是否可靠？,某厂家给定产品玻璃光纤中,Cu,含量为,0.5ppm,，,Pb,含量,0.1ppm,，他们所用的仪器为,ICP-MS,。请问该数据是否可靠？,REE,配分曲线对数据可靠性的评价,数据分析原理,部分元素具有相同或相似的地球化学行为（如,REE,）,;,不同元素在不同地质作用过程的地球化学行为存在差别（相容性,/,活动性变化）；,地质作用过程中的物理、化学条件对元素的地球化学行为具有影响（如,P-T-X-,f,O2,等）,.,部分元素具有相同或相似的地球化学行为（如,REE,）,下图所示趋势的原因是什么？,平衡部分熔融作用,La,L,/La,O,=1/(D,La,(1-F)+F),Sm,L,/Sm,O,=1/(D,Sm,(1-F)+F),La,L,=La,O,/D,La,+F(1-D,La,)F=(La,O,-La,L,D)/La,L,(1-D),Sm,L,=Sm,O,/D,Sm,+F(1-D,Sm,)F=(Sm,O,-Sm,L,D)/Sm,L,(1-D),La,L,/Sm,L,=La,L,(D,Sm,b-D,La,)/bSm,O,+La,O,/bSm,O,b=(1-D,La,)/(1-D,Sm,),D,Sm,D,La,b,1,D,Sm,b-D,La,0,K0,D,La,D,Sm,0,应用实例,汉诺坝玄武岩中的麻粒岩包体,汉诺坝玄武岩中的麻粒岩包体,汉诺坝玄武岩 中的麻粒岩包体,石榴石边部明显富集,MREE,SD014,SD006,0.01,高,Rb,Sr,Cs,Ba,U,Pb,CCSD,榴辉岩,绿辉石边部明显富集所有,REE,角闪岩相退变质作用与,Rb,Sr,Cs,Ba,U,Pb,密切相关,磷灰石的成分分带,10000,Q,Q,磷灰石,绿辉石,石榴石,利用石榴石、单斜辉石、磷灰石中,REE,的分配系数,随温度变化的实验资料对该过程进行了模型计算,模型计算,假设温度从,800,升温到,830,磷,灰石,绿辉石和石,榴石分别占全岩,1.5%,48.5%,和,50%,温度升高,磷灰石释放,LREE-MREE,、石榴石释放,HREE,REE,在榴辉岩各矿物相间重新分配,石榴石、绿辉石、磷灰石的,REE,成分环带,受增温作用影响,直径,(d),为,0.4mm,和,1mm,的石榴石和磷灰石晶体核部,REE,组成发生变化所需要的时间与温度之间的关系,.,计算方法为,Dt/r,2,=0.03,(Crank,，,1965),其中,t,是半径为,r,的矿物,(,设为球体,),核部,REE,组成发生变化所需要的最小时间,D,为,REE,在矿物中的扩散系数,.,因为石榴石中,Sm,和磷灰石中,Yb,的环带特征明显,并且具有相应的实验扩散系数资料,所以选择石榴石中,Sm,和磷灰石中,Yb,进行计算,.,石榴石,Sm,的扩散系数取自,Tirone et al.(2005),磷灰石,Yb,的扩散系数取自,Cherniak(2000).,模型计算,金红石,Zr,温度计 存在巨大应用潜力,100um,榴辉岩中金红石,包裹体金红石：处于石榴石中，大小,50150,m,粒间金红石：处于石榴石和绿辉石之间，大小,80250,m,CCSD,榴辉岩,包裹体金红石温度,(,平均,614,),低于粒间金红石温度,(,平均,660,),ZMK,粒间金红石温度是否代表超高压峰期变质温度？,该温度计的结果是否有地质意义？,粒间金红石核部温度较边部高，且核部温度随粒径增加而升高。,在,660,条件下金红石中,Zr,扩散,1,m,需要,12,万年，因此粒间金红石边部,Zr,含量的降低不太可能由正常扩散作用引起。,粒间金红石,Zr,含量受到了后期流体活动的改造？！,金红石中,Zr,扩散速率方程（据,Watson,）,粒间金红石边部明显富集,Pb,、,Sr,，但,Zr,逐渐降低。,低温的机理是什么？,Fig.2,Petrologic and geochemical profile of the CCSD-MH(following Zhang et al.(2004).Circles on the petrologic profile mark the sampling depths.Layer*=layers classified by Zhang et al.(2004)based on petrology.,Fig.3,Plots of TiO,2,vs.,Nb and Zr for eclogites from CCSD-MH and ultramafic rocks from ZK703(a,b)and oceanic gabbros from the Indian Ridge(c,d).Eclogites(literatures)from(Zhang et al.,2004;Zhang et al.,2000b).Modern continental flood basalts(,georoc.mpch-mainz.gwdg.de/georoc/,)are shown for comparison.Oceanic gabbros from(Coogan et al.,2001;Hart et al.,1999).,Fig.7,Fig.7 Plots of Eu anomalies,vs.,Fe,2,O,3,total,and TiO,2,for eclogites and ultramafic rocks.Dark pentacle is the average of modern continental flood basalts(CFB)with MgO 8 wt%(n=562,georoc.mpch-mainz.gwdg.de/georoc/).Gray line shows Fe,2,O,3,total,range of cumulates of olivine+pyroxene,which is calculated assuming D,Fe,ol,=0.51-1.55(Beattie,1994),D,Fe,cpx,=0.57-1.04(Dale and Henderson,1972).,Fig.8,Fig.8 Plots of MgO,-,TiO,2,and-V and Fe,2,O,3,total,-MgO and-V.Solid cycles are data of this work,rectangles are data from Zhang et al.(2004;2000b).1=trend of pyroxene olivine crystallization,2=trend of magnetite crystallization,3=trend of melt evolution.Pentacle is the average of continental flood basalts with MgO8 wt%(,georoc.mpch-mainz.gwdg.de/georoc/,).,Fig.9,Fig.9 Plot of Ni,vs,.MgO.Gray diamond represents mantle composite xenoliths formed by melt-peridotite interaction(Liu et al.,2005).DM:depleted mantle(Salters and Stracke,2004).Solid line shows fractional crystallization(F=4%)of 080%ol+8010%cpx+1020%opx with 2%trapped melt from basaltic magma(Table 6).Crosses on the line indicate variations of olivine proportions(0-80%).K,D(Fe/Mg),(=(Fe/Mg),crystal,/(Fe/Mg),melt,)were assumed to be 0.29,0.26 and 0.25 for ol,cpx and opx,respectively(Baker and Eggler,1987).Partition coefficients of Ni between basaltic melt and ol,cpx and opx are listed in Table 6.,Fig.10,Fig.10 TiO,2,-Nb,-Zr variations during fractional crystallization of cpx+pl+opx+mt with 15%trapped melt following 5%fractional crystallization of ultramafic rocks(70%ol+20%cpx+10%opx)from a basaltic magma.mt10 and mt20 are cumulates of 40%cpx+35%pl+15%opx+10%mt and 30%cpx+35%pl+15%opx+20%mt,respectively.pl80 and pl30 are magnetite-free cumulates of 80%pl+15%opx+5%cpx and 55%cpx+30%pl+15%opx,respectively.Compositions of basaltic magma and partition coefficients used in modeling are listed in Table 6.,研究方法,REE,配分曲线,/REE pattern,蛛网图,/Spider Diagrams,元素比值和含量变化图,相关分析,模型计算,REE,配分曲线,/REE pattern,选择归一化值,球粒陨石（,CI,）,北美页岩（,NASC,）,后太古代澳大利亚页岩（,PAAS,）,某特殊样品,Chondrite values used in normalizing REE(ppm),Reference,Notes,La,Ce,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Ho,Er,Tm,Yb,Lu,Taylor and McLennan(1985),Avg.CI,0.367,0.957,0.137,0.711,0.231,0.087,0.306,0.058,0.381,0.085,0.249,0.036,0.248,0.038,McDonough et al.(1991),Primitive mantle,0.708,1.833,0.278,1.366,0.444,0.168,0.595,0.108,0.737,0.163,0.479,0.074,0.480,0.074,Wakita et al.(1971),Composite(12),0.340,0.910,0.121,0.640,0.195,0.073,0.260,0.047,0.300,0.078,0.200,0.032,0.220,0.034,Haskin et al.,(1968),Composite(9),0.330,0.880,0.112,0.600,0.181,0.069,0.249,0.047,0.070,0.200,0.030,0.200,0.034,Masuda(1973),Leedey,0.378,0.976,0.716,0.230,0.087,0.311,0.390,0.255,0.249,0.039,Nakamura(1974),Composite,0.329,0.865,0.630,0.203,0.077,0.276,0.343,0.225,0.220,0.034,Evensen et al.(1978),Avg.CI,0.245,0.638,0.096,0.474,0.154,0.058,0.204,0.037,0.254,0.057,0.166,0.026,0.165,0.025,Boynton(1984),Avg.CI,0.310,0.808,0.122,0.600,0.195,0.074,0.259,0.047,0.322,0.072,0.210,0.032,0.209,0.032,Standard sedimentray compositions used in normalizing REE(ppm)in sedimentary rocks,Gromet et al.,1984,NASC,31.1,67.0,30.400,5.98,1.25,5.50,0.85,5.54,3.28,3.11,0.46,Haskin and Frey,1966,NASC,39.0,76.0,10.30,37.000,7.00,2.00,6.10,1.30,1.40,4.00,0.58,3.40,0.60,Haskin and Haskin,1966,NASC,32.0,70.0,7.90,31.000,5.70,1.24,5.21,0.85,1.04,3.40,0.50,3.10,0.48,Haskin et al.,1968,NASC,32.0,73.0,7.90,33.000,5.70,1.24,5.20,0.85,1.04,3.40,0.50,3.10,0.48,Gromet et al.,1984,NASC,31.1,66.7,27.400,5.59,1.18,0.85,3.06,0.46,Haskin and Haskin,1966,ES,41.1,81.3,10.40,40.100,7.30,1.52,6.03,1.05,1.20,3.55,0.56,3.29,0.58,McLennan,1989,PAAS,38.2,79.6,8.83,33.900,5.55,1.08,4.66,0.77,4.68,0.99,2.85,0.41,2.82,0.43,Taylor and McLennan,1981,Upper crust,30.0,64.0,7.10,26.000,4.50,0.88,3.80,0.64,3.50,0.80,2.30,0.33,2.20,0.32,Elderfield and Greaves,1982,Typical seawater,20.8,9.64,21.100,4.32,0.82,5.20,5.61,4.94,4.66,Hoyle et al.,1984,River water,425,601,365,80.4,20.7,83.5,97.9,64.6,51.7,Sample,La,Ce,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Ho,Er,Tm,Yb,Lu,CI,0.367,0.957,0.137,0.711,0.231,0.087,0.306,0.058,0.381,0.085,0.249,0.036,0.248,0.038,SFX02,93.0,181,25.2,93.8,15.1,4.11,11.7,1.22,5.23,0.84,2.14,0.28,1.57,0.23,SFX13,86.9,171,23.6,88.8,14.3,3.98,11.2,1.13,4.99,0.80,2.04,0.26,1.54,0.23,SFX19,86.7,168,23.6,88.5,14.3,3.89,11.1,1.15,4.96,0.82,2.04,0.28,1.50,0.24,SFX27,87.3,170,23.7,88.7,14.1,3.91,11.0,1.16,5.05,0.84,2.07,0.27,1.56,0.23,CI-normalized,SFX02,253.3,189.5,183.6,132.0,65.5,47.2,38.3,21.0,13.7,9.9,8.6,7.7,6.3,6.1,SFX13,236.8,179.1,172.3,124.9,61.9,45.7,36.5,19.5,13.1,9.4,8.2,7.4,6.2,5.9,SFX19,236.2,175.5,172.1,124.5,61.8,44.7,36.2,19.8,13.0,9.6,8.2,7.8,6.0,6.2,SFX27,237.9,177.8,173.1,124.7,61.1,44.9,36.0,20.0,13.3,9.8,8.3,7.7,6.3,6.0,不同矿物的影响,Ce,和,Eu,异常；,中稀土元素相对于轻、重稀土元素的富集可能反映角闪石的控制作用；,轻、重稀土元素的分异则可能反映橄榄石、辉石的作用等；,极端的重稀土元素亏损则可能反映了石榴石的作用。,河水和海水的,REE,配分曲线,不同矿物的影响,2.,蛛网图,/Spider Diagrams,按照元素相容性顺序，利用球粒陨石、原始地幔等进行标准化后所作的一种线条图。,Different estimates different ordering(poor standardization),选择归一化值,火成岩,Primitive Mantle,Chondrite,MORB,沉积岩,NASC,平均大陆上地壳,平均显生宙灰岩,平均显生宙石英砂岩,蛛网图,/Spider Diagrams,MORB-normalized Spider,Ocean island basalt plotted on a mid-ocean ridge basalt(MORB)normalized spider diagram of the type used by Pearce(1983).Data from Sun and McDonough(1989).From Winter(2001)An Introduction to Igneous and Metamorphic Petrology.Prentice Hall.,Trace elements in CPX,火成岩蛛网图解释,两大类元素,活动性强的大离子亲石元素,活动性较弱的高场强元素,特定矿物对部分元素的控制作用,如,Zr,、,P,、,Sr,、,Ti,、,Nb,、,Ta,等,个别元素的特殊指示意义,如,Nb,、,Ta,（地壳混染）,强活动元素（流体活动或地壳混染）,沉积岩蛛网图解释,沉积物源区组成,某些特殊矿物,风化程度,部分熔融过程中的相容性,流体作用中的活动性,用某一特殊样品归一化,相对于新鲜部分微量元素呈现出互补的关系,3.,元素比值,元素比值通常比元素含量在识别某矿物或地质作用上更有效。,指示分异程度：,(La/Yb),N,、,(La/Sm),N,指示沉积物源区：,La/Sc,、,Th/Sc,、,La/Co,、,Th/Co,、,Eu/Sm,、,La,、,Lu,Ni/Cr or Ni/Sc,可以区别由部分熔融或分馏结晶作用形成的岩石中橄榄石和辉石的作用,Nb/Ta,Nb/La,Zr/Hf,4.,双变量图,不相容元素,对部分熔融作用敏感,识辨源区特征,相容元素,对分离结晶作用敏感,0,10,20,30,40,50,0,10,20,30,40,50,60,70,Archean TTG&,Slab melts,(La/Yb),N,Post-Archean granites&modern arcs,High(La/Yb),N,=garnet in source:,lower crust or upper mantle?,Y(ppm),Xinglonggou hi Mg lavas,Fig.3,Plots of TiO,2,vs.,Nb and Zr for eclogites from CCSD-MH and ultramafic rocks from ZK703(a,b)and oceanic gabbros from the Indian Ridge(c,d).Eclogites(literatures)from(Zhang et al.,2004;Zhang et al.,2000b).Modern continental flood basalts(,georoc.mpch-mainz.gwdg.de/georoc/,)are shown for comparison.Oceanic gabbros from(Coogan et al.,2001;Hart et al.,1999).,Fig.8,Fig.8 Plots of MgO,-,TiO,2,and-V and Fe,2,O,3,total,-MgO and-V.Solid cycles are data of this work,rectangles are data from Zhang et al.(2004;2000b).1=trend of pyroxene olivine crystallization,2=trend of magnetite crystallization,3=trend of melt evolution.Pentacle is the average of continental flood basalts with MgO8 wt%(,georoc.mpch-mainz.gwdg.de/georoc/,).,50,60,70,80,10,15,20,25,30,35,Y(ppm),Fe/Mn,Hawaii OIB,MORB,CFB,50,60,70,80,1,1.5,2,2.5,Yb(ppm),Fe/Mn,Hawaii OIB,石榴石的作用,石榴石,/,单斜辉石富集地幔,D,(Y,Yb),cpx/basalt,1 D,Fe,/D,Mn,cpx/basalt,1 D,Fe,/D,Mn,grt/basalt,1,119-136 Ma,玄武岩,:,斜方辉石富集的地幔,0.0,100.0,200.0,300.0,400.0,500.0,600.0,50,60,70,80,90,Fe/Mn,Ni(ppm),110 Ma,玄武岩,119-136 Ma,玄武岩,Hawaii,玄武岩平均值,5.,模型计算,TiO2-Nb,-Zr variations during fractional crystallization of cpx+pl+opx+mt with 15%trapped melt following 5%fractional crystallization of ultramafic rocks(70%ol+20%cpx+10%opx)from a basaltic magma.mt10 and mt20 are cumulates of 40%cpx+35%pl+15%opx+10%mt and 30%cpx+35%pl+15%opx+20%mt,respectively.pl80 and pl30 are magnetite-free cumulates of 80%pl+15%opx+5%cpx and 55%cpx+30%pl+15%opx,respectively.,10,15,20,25,0,50,100,150,Nb(ppm),Nb/Ta,119-136 Ma,中生代玄武岩,新生代玄武岩,104 Ma,中生代碱锅玄武岩,CFB,PM,110Ma),Cenozoic basalts,Jianguo Basalts(104Ma),CFB,PM,岛弧型微量元素组成,再循环基性下地壳,(,太古宙变玄武岩,),在金红石稳定域内,20%,的部分熔融,橄榄岩和经,20%,长英质,熔体提取后的榴辉岩,残余,(1%,金红石,),混合,橄榄岩和熔体通过渗滤,反应发生混合,(,假设,10%,的熔体通过与橄榄石反应转变成了辉石,),橄榄岩,+,榴辉岩混合物,经,15%,的部分熔融作用,（金红石不再稳定）,熔体,+,橄榄岩反应产物,(,富斜方辉石辉石岩,),发生,15%,的部分熔融,110 Ma,玄武岩,119-136 Ma,玄武岩,橄榄岩,+,含,1%,金红石榴辉岩混合物经,15%,的部分熔融,(,金红石不再稳定,),熔体,+,橄榄岩反应产物,(,富斜方辉石辉石岩,),发生,15%,的部分熔融,From A.W.Hofmann,0.00,2.00,4.00,6.00,8.00,10.00,56,58,60,62,64,66,68,70,72,sample/chondrite,La Ce Nd Sm Eu Tb Er Yb Lu,67%Ol 17%Opx 17%Cpx,0.00,2.00,4.00,6.00,8.00,10.00,56,58,60,62,64,66,68,70,72,sample/chondrite,La Ce Nd Sm Eu Tb Er Yb Lu,57%Ol 14%Opx 14%Cpx 14%Grt,Garnet and Plagioclase effect on HREE,0.00,2.00,4.00,6.00,8.00,10.00,sample/chondrite,60%Ol 15%Opx 15%Cpx 10%Plag,La Ce Nd Sm Eu Tb Er Yb Lu,