Uranium-lead dating method at the Pará-Iso isotope geology laboratory, UFPA, Belém - Brazil

Anais da Academia Brasileira de Ciências

Robert S. Krymsky¹  Moacir J.b. Macambira¹  Jean-michel Lafon¹  Gérson S. Estumano¹ 

[1] ,Universidade Federal do Pará Pará-Iso Centro de GeociênciasBelém PA ,Brasil

关键词: U-Pb dating;    zircon;    accessory mineral;    isotope dilution;    geocronologia U-Pb;    zircão;    minerais acessórios;    diluição isotópica;   

DOI  :  10.1590/S0001-37652007000100014

来源: SciELO

【 摘 要 】

Analytical procedures for U-Pb isotope dilution analyses at the Pará-Iso isotope geology laboratory of the Federal University of Pará (UFPA) are described in detail. The procedures are applied to zircon, titanite, rutile, apatite, columbite-tantalite and whole rock. Reagent preparation and chemical processing are done in clean-room conditions. Samples are dissolved using TeflonTM microcapsules in steel jacket TeflonTM Parr InstrumentTM bomb or TeflonTM screw cap containers. U and Pb are separated using anion exchange AG 1x8 resin columns. Typical blanks for mineral sample amounts of 0.01 to 1.0 mg are less than 1 pg U and 20-30 pg Pb. Isotope analysis of the U and Pb from the same filament are carried out using a Finnigan MAT 262 mass-spectrometer in static and dynamic modes. The current analytical level is demonstrated on analyses of international standard zircon 91500 with three different 235U-205Pb and 235U-208Pb isotope tracers and whole rock standards. Results of analyses of two zircon samples are also presented.

【 授权许可】

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