钾长石标准合成及其中Pb同位素组成LA-MC-ICPMS原位微区分析研究
详细信息    本馆镜像全文|  推荐本文 |  |   获取CNKI官网全文
摘要
长石是常见的造岩矿物之一,普遍存在于各类岩石中。长石的铅同位素组成是示踪岩石形成和演化历史的重要途径,通过铅同位素地球化学研究,不仅可以确定成矿时代或模式年龄,而且还可判断成矿物质来源、矿床成因等。然而,传统的整体分析方法得到的铅同位素组成是整个矿物或一些矿物的混合物,可能不具有实际地质意义。这就需要具有微区Pb同位素分析功能的分析技术。激光剥蚀多接收等离子体质谱(LA-MC-ICPMS)技术是进行原位微区分析微量元素和同位素的重要设备之一,然而,由于该技术属于相对分析,即分析过程中实际样品的分析数据是在与标准样品分析信号对比基础上获取的,标准样品与实际样品基体的匹配程度将直接影响分析结果的准确度,与样品具有类似基体的标准物质就成为影响该技术成功应用的关键影响因素。因此,研制与基体相近的长石玻璃标准也是利用LA-MC-ICPMS进行微区Pb同位素组成分析的关键问题。本论文利用高温炉对天然钾长石粉末(加入了单硅酸铅)进行熔融的实验条件研究,研制出钾长石玻璃,并利用LA-Q-ICPMS和LA-MC-ICPMS技术分别就其中的主、微量元素和Pb同位素组成进行详细的均一性研究,经过反复试验和对比,获得如下结论:
     1.熔融实验之前需要将初始钾长石粉末研磨至1300目以上;
     2.确定钾长石标准玻璃的合成条件为:熔融温度1680℃、熔融时间2小时,采用液氮淬火;
     3.经检验合成的钾长石标准玻璃具有很好的均一性。其主量元素RSD%优于5%,微量元素RSD优于10%,内部Pb同位素比值为1.90779±0.00009 (208Pb/206Pb,2s), 0.75899±0.00004(207Pb/206Pb,2s),20.909±0.002(206Pb/204Pb,2s),15.871±0.002(207Pb/204Pb,2s)和39.888±0.005 (208Pb/204Pb,2s),相应的RSD分别为0.007%,0.008%,0.016%,0.016%和0.021%。
     4、利用合成的钾长石标准玻璃作外标,对地质样品中长石的铅同位素开展了原位分析,结果与前人利用传统化学方法分析得到的结果在误差范围内完全吻合。
The feldspar is one of the common rock forming minerals. The Pb isotopic composition of feldspar could be used as tracer of the rock formation and the history evolution. Based on lead isotope geochemistry research, one may not only determine the metallogenetic epoch or the modle age, but judge the origination of mineralization material metallogenesis. The traditional bulk rock analysis of lead isotopic composition can only obtain the mixed lead isotopes and may not have practical significance. This requires the in situ analytical techniques. The laser ablation coupled with multiple-collector inductively coupled plasma mass spectrometer (LA-MC-ICPMS) is one of the most important in situ micro analytical techniques for lead isotopic coposition measurement. However, all kind of in situ micro analycial techniques need external standard materials to calibrate instrumental fracationation and other obstacles to get elemental and isotopic compositions of samples. The matrix matched external calibration standards are the short cut way to obtain the geochemical information of relative geological samples in most applications. There is no feldspar standards for precise lead isotope analysis of K-feldspar using in situ analytical techniques, such as LA-MC-ICPMS. We tried to synthesize K-feldspar glasses using high temperature furnace with monosilicate lead dopted K-feldspar powder and evaluated the homogeneity of trace elements and lead isotopic compositions.
     1. The grinding step prior to melting is one of the key step for homogenized glasses synthesion. The K-feldspar need to be grinded to 1300mesh instead of 200mesh to get final homogenized glasses due to high viscosity melt;
     2. The experimental coditions for K-feldspar glasses synthesion are:heating temperature 1680℃,heating duration time 2 hours and liquid nitrogen quenching;
     3. The homogeneity of the synthesized K-feldspar glasses are:RSD% of major and trace elements are less than 5% and 10%, respectively. Lead isotopic compositions are 1.90779±0.00009 (208Pb/206Pb,2s),0.75899±0.00004 (207Pb/206Pb,2s),20.909±0.002 (206Pb/204Pb,2s),15.871±0.002 (207Pb/204Pb,2s)和39.888±0.005 (208Pb/204Pb,2s),while the relative RSD of these ratios are 0.007%,0.008%,0.016%,0.016% and 0.021%, respectively.
引文
[1]Chow, T. J. and Johnstone, M. S. Lead isotopes in gasoline and aerosols of Los Angeles Basin, California. Science 1965,147,502-503.
    [2]Chow, T. J. and Earl, J. L. Lead isotopes in North American coals. Science 1972,176, 510-511.
    [3]Doe, B. R. and Zartman, R. E. Plumbotectonics. In:Barnes, H. L. (Ed.) Geochemistry of Hydrothermal Ore Deposits.Wiley,1979,22-70.
    [4]Harrison, R. M. and Laxen, D. P. H. Lead Pollution:Causes and Control. Chapman and Hall.1981
    [5]Dewolf C P., Mezger K... Lead isotope analyses of leached feldspars:constraints on the early crustal history of the Grenville Orogen. Geochim. Cosmochim.Acta,1994,58(24): 5537-5550.
    [6]Sturges, W. T. and Barrie, L. A. Lead 206/207 isotope ratios in the atmosphere of North America as tracers of US and Canadian emissions. Nature 1987,329,144-146.
    [7]Allegre, C. J., Manhes, G. and Gopel, C. The age of the Earth. Geochim. Cosmochim. Acta 1995,59,1445-56.
    [8]Galer, S. J. G. and Goldstein, S. L. Influence of accretion on lead in the Earth. In:Basu, A. and Hart, S. R. (Eds.) Earth Processes:Reading the Isotopic Code. Geophys. Monograph 1996, 95,75-98. American Geophysical Union.
    [9]Tera, F. and Carlson, R.W. Assessment of the Pb-Pb and U-Pb chronometry of the early solar system. Geochim. Cosmochim.1999, Acta 63,1877-1889.
    [10]Jones, C. E., Halliday, A. N., Rea, D. K. and Owen, R. M. Eolian inputs of lead to the North Pacific.Geochim. Cosmochim.2000, Acta 64,1405-16.
    [11]Harlavan, Yehudit and Erel, Yigal. The release of Pb and REE from granitoids by the dissolution of accessory phases. Geochimica et Cosmochimica 2002. Acta,66(5)837-848
    [12]Gagnevin, D., Daly, J.S., Waight, T.E., Morgan, D. and Poli, G., Pb isotopic zoning of K-feldspar megacrysts determined by Laser Ablation Multi-Collector ICP-MS:Insights into granite petrogenesis. Geocheim. Cosmochim.2005.Acta,69(7):1899-1915.
    [13]张景廉,朱炳泉,陈义贤and涂湘林等.辽河断陷下第三系烃源岩有机质Pb和Sr 同位素研究.科学通报,1999.44(11):1222-1225.
    [14]张景廉,朱炳泉,陈义贤,王斌婷,张成君,王大锐Pb, Sr, Nd同位素与辽河油田油源对比.地学前缘,2000a.7(2):345-351.
    [15]张景廉,朱炳泉,张平中Pb-Sr-Nd同位素体系在石油地球化学中的应用.地球科学进展,1997a.12(1):58-61.
    [16]张景廉,朱炳泉,张平中,涂湘林等.克拉玛依乌尔禾沥青脉Pb-Sr-Nd同位素地球化学.中国科学D辑,1997b.27(4):325-330.
    [17]朱炳泉.矿石Pb同位素三维空间拓补图解用于地球化学省与矿种区划.地球化学,1993.22(3):209-216.
    [18]朱炳泉.地球科学中同位素体系理论与应用—兼论中国大陆壳幔演化[M].科学出版社,北京,1998.330 pp.
    [19]朱炳泉.固体地球科学的同位素体系理论.科学出版社,北京,1998.321 pp.
    [20]朱炳泉,常向阳.地球化学省与地球化学边界.地球科学进展,2001b.16(2):153-162.
    [21]朱炳泉,常向阳,胡耀国,张正伟.滇-黔边境鲁甸沿河铜矿床的发现与峨眉山大火成岩省找矿新思路.地球科学进展,2002.17(6):912-917.
    [22]朱炳泉,常向阳,邱华宁,王江海,邓尚贤.云南前寒武纪基底形成与变质时代及其成矿作用年代学研究.前寒武纪研究进展,2001a.24(2):75-82.
    [23]张宏飞,高山and张本仁,钟增球,贾望鲁,王林森.大别山地壳结构的Pb同位素地球化学示踪.地球化学,2001.30(4):395-401.
    [24]金正耀.铅同位素示踪方法应用于考古研究的进展.地球学报,2003.24(6):548-551.
    [25]李献华,桂训唐,刘菊英.西藏曲水岩基的Pb、Sr同位素组成及其三元混合成因模式.地球化学.1987,16(1):60-66
    [26]李龙,郑永飞,王峥嵘.铅同位素动力学模型及其在示踪花岗岩成因中的应用.地学前缘,2000.7(2):413-429
    [27]常向阳,陈良忠,胡世学,王江海,朱炳泉.含澄江动物群地层的Pb-Pb同位素定年.地球学报,2004.25(2):181-184.
    [28]袁洪林.溶液进样和激光剥蚀等离子体质谱中地球化学中应用.中国地质大学(武汉)博士研究生论文,武汉,2002.151 pp.
    [29]袁洪林,吴福元, 高山,柳小明,徐平,孙德有.中国东部新生代侵入体的锆石 激光探针年龄测定与稀土元素成分分析.科学通报,2003.48(14):1511—1520
    [30]袁洪林,靳兰兰,高山,宗春蕾,戴梦宁In situ Pb isotope analysis of glass and feldspar by LA-MC-ICPMS.2005年全国岩石学与地球动力学研讨会.
    [31]Zartman R E, Haines S M. The plumbotectonic model for Pb isotopic systematic among major terrestrial reservoirs—a case for bidirectional transport[J]. Geochima et Cosmochima Acta,1988,52:1327-1339.
    [32]沈渭洲.稳定同位素地球化学[M].北京:原子能出版社,1987.
    [33]朱炳泉.矿石Pb同位素三维空间拓扑图解用于地球化学省和矿种区划[J].地球化学,1993,(3):209—216.
    [34]魏菊英,王关玉.同位素地球化学[M].北京:地质出版社。1988:59—80.
    [35]张理刚.长石铅和矿石铅同位素组成及其地质意义[J].矿床地质,1988,7(2):55—64.
    [36]Bodet Francois, Scharer Urs. Pb isotope systematics and time-integrated ThrU of SE-Asian continental crust recorded by single K-feldspar grains in large rivers. Chem. Geol.; 2001.177:265-85.
    [37]Gagnevin D., Daly J. S., Waight T. E., Morgan D., Poli G.. Pb isotopic zoning of K-feldspar megacrysts determined by Laser Ablation Multi-Collector ICP-MS:Insights into granite petrogenesis. Geocheim. Cosmochim. Acta; 2005.69(7):1899-915.
    [38]Resano M., Marzo M. P., Alloza R., Saenz C., Vanhaecke F., Yang L., Willie S., Sturgeon R. E. Laser ablation single-collector inductively coupled plasma mass spectrometry for lead isotopic analysis to investigate evolution of the Bilbilis mint. Analytica Chimica Acta; 2010.677(1):55-63.
    [39]Wolff J.A., Ramos F.C.. Pb isotope variations among Bandelier Tuff feldspars:No evidence for a long-lived silicic magma chamber. Geology; 2003.31(6):533-36.
    [40]Dewolf C P., Mezger K.. Lead isotope analyses of leached feldspars:constraints on the early crustal history of the Grenville Orogen. Geochim. Cosmochim.Acta,1994.58(24): 5537-5550.
    [41]郭敬辉,石听,卞爱国,许荣华,翟明国等.商干地区早元古代花岗岩长石Pb同位素组成和锆石U-Pb年龄:变质与地壳熔融作用及构造-热事件演化.岩石学报,1999.15(2):199-207.
    [42]Bodet, F. and Scharer, U., Pb isotope systematics and time -integrated ThrU of SE-Asian continental crust recorded by single K-feldspar grains in large rivers. Chem. Geol.,2001.177: 265-285.
    [43]Gagnevin, D., Daly, J.S., Waight, T.E., Morgan, D. and Poli, G., Pb isotopic zoning of K-feldspar megacrysts determined by Laser Ablation Multi-Collector ICP-MS:Insights into granite petrogenesis.Geocheim. Cosmochim. Acta,2005.69(7):1899-1915.
    [44]邱啸飞,凌文黎.微区原位普通铅同位素分析技术及其地质应用进展[J].地质科技情报,2009,28(5):118-124
    [45]Wilde, S.A., Valley, J.W., Peck, W.H. and Grahams, C.M., Evidence from detrital zircons for the existence of continental crust and oceans on the Earth 4.4 Gyr ago. Nature, 2001.409:175-178.
    [46]Ulrich,T., Guenther, D. And Heinrich, C.A. Gold concentrations of magmatic brines and the metal budget of porphyry copper deposits. Nature,1998.399:676-679.
    [47]Sun,W., Arculus, R.J., Kamenetsky, V.S. and Binns, R.A. Release of gold-bearing fluids in convergent margin magmas prompted by magnetite crystallization. Nature 2004.431, 975-978.
    [48]徐平,关鸿,袁超,孙敏,周新华,John Malps激光探针等离子体质谱用于锆石207Pb-206Pb的分析和校正方法的进一步探讨.地球化学,28:136-143.
    [49]Horn, I., Guillong, M. and Giinther, D., Wavelength dependant ablation rates for metals and silicate glasses using homogenized laser beam profiles—implications for LA-ICP-MS. Applied SurfaceScience:2001.1-12.
    [50]Jochum, K.P. et al., Lead isotope ratio measurements in geological glasses by laser ablation-sector field-ICP mass spectrometry (LA-SF-ICPMS). international Journal of Mass Spectrometry,2005.242:281-289.
    [51]Paul, B., Woodhead, J.D. and Hergt, J., Improved in situ isotope analysis of low-Pb materials using LA-MC-ICP-MS with parallel ion counter and Faraday detection. J. Anal. At. Spectrom.,2005.20:1350-1357
    [52]Albarede F., T.P., Blichert-Toft J., BoyetM., Agranier A., And Nelson B.. Precise and accurate isotopic measurements using multiple-collector ICPMS. Geocheim. Cosmochim. Acta,2004.68(12):2725-2744.
    [53]Woodhead, J., Hergt, J., Shelley, M., Eggins, S. and Kemp, R., Zircon Hf-isotope analysis with an excimer laser, depth profiling, ablation of complex geometries, and concomitant age estimation. Chem. Geol.,2004.209:121-135.
    [54]Pettke Thomas, Oberli Felix, Audetat Andreas, Wiechert Uwe, Harris Caroline R., Heinrich Christoph A.2011. Quantification of transient signals in multiple collector inductively coupled plasma mass spectrometry:accurate lead isotope ratio determination by laser ablation of individual fluid inclusions. Journal of Analytical Atomic Spectrometry.
    [55]Halliday, A.N. et al., Applications of multiple collector-ICPMS to cosmochemistry, geochemistry, and paleoceanography. Geocheim. Cosmochim. Acta,1998.62(6):919-940.
    [56]Pomies, C., Cocherie, A., Guerrot, C., Marcoux, E., Lancelot, J., Assessment of the precision and accuracy of lead-isotope ratios measured by TIMS for geochemical applications: example of massive sulphide deposits Rio Tinto Spain. Chem. Geol.,1998.144:137-149.
    [57]Galer, S.J.G., Optimal double and triple spiking for high precision lead isotopic measurement. ChemGeol.,1999.157:255-274.
    [58]Thirlwall, M.F., Inter-laboratory and other errors in Pb isotope analyses investigated using a 207Pb-204Pb double spike. Chem. Geol.,2000.163:299-322.
    [59]王林森,张利.用双稀释剂法测定地质样品中的铅同位素组成.矿物岩石,2003.23(2):44-48.
    [60]Albarede F., T.P., Blichert-Toft J., BoyetM., Agranier A., And Nelson B.. Precise and accurate isotopic measurements using multiple-collector ICPMS. Geocheim. Cosmochim. Acta,2004.68(12):2725-2744.
    [61]Rehkamper, M. and Mezger, K., Investigation of matrix effects for Pb isotope ratio measurements by multiple collector ICPMS:verification and application of optimised analytical protocols. J. Anal. At. Spectrom.,2000.15:1451-1460.
    [62]Quetel C.R., Thomas B., Donard O.F.X., Grousset F.E.. Factorial optimization of data acquisition factors for lead isotope ratio determination by inductively coupled plasma mass spectrometry. Spectrochimica Acta Part B,1997.52,177-187
    [63]Barbasete, M. et al., Evaluation of the accuracy of the determination of lead isotope ratios in wine by ICP MS using quadrupole, multicollector magnetic sector and time-of-flight analyzers.2001.
    [64]Christensen J N, Halliday A N, Godfrey L V, et al. Climate and ocean dynamics and the lead isotopic records in Pacificferro manganese crusts[J]. Science,1997,277:913-918.
    [65]Sie S H, Niklaus T R, Suter G F, et al. Microbeam AMS:Prospects of new geological applications [J]. Nuclear Instruments and M ethods in Physics Research B,1997,123:11 2-121.
    [66]Sic S H, Sims D A, Suter G, Fet al. Precision Pb and S isotopic ratio measurements by microbeam AMS[J]. Nuclear Instruments and M ethods in Physics Research B,2000, 172:228-234.
    [67]Sie S H, Niklaus T R, Sims D A, et al. AUSTRALIS:A new tool for the study of isotopic systems and geochronology in mineral systems[J]. Australian Journal of Earth Sciences,2002,49:601-611.
    [68]Jochum K P, Stall B, Herwig K, et al. Lead isotope ratio measurements in geological glasses by laser ablation sector field ICP mass spectrometry (LA—SF—ICPMS)[J]. International Journal ofMass Spectrometry,2005,242:281-289.
    [69]靳兰兰,姜劲峰,胡圣虹,等.双气流路—激光剥蚀电感耦合等离子体质谱测定铅同位素比值[J].分析化学,2007,35(2):191-195.
    [70]Meffre S, Large R R, Scott R, et al. Age and pyrite Pb—isotope composition of the giant Sukhoi Log sedimenthosted gold deposit, Russia[J]. Geochimica et Cosmochimica Acta,2008,72:2377-2391.
    [71]Woodhead J, Hergt J, Meffre S, et al. In situ Pb—isotope analysis of pyrite by laser ablation (multicollector and quadrupole)ICPMS[J]. Chemical Geology,2009,262:344-354.
    [72]Zartman, R. E. and Doe, B. R.1981. Plumbotectonics) the model. Tectonophys.75, 135-162.

© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号

地址:北京市海淀区学院路29号 邮编:100083

电话:办公室:(+86 10)66554848;文献借阅、咨询服务、科技查新:66554700