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https://repositorio.ufba.br/handle/ri/7658
metadata.dc.type: | Artigo de Periódico |
Title: | Lead isotope evidence for recent uranium mobility in geological formations of Brazil: implications for radioactive waste disposal |
Other Titles: | Applied Geochemistry |
Authors: | Iyer, Sundaram Sankara Subba Babinski, M. Marinho, M. M. Barbosa, J .S. F. Sato, I. M. Salvador, V. L. |
metadata.dc.creator: | Iyer, Sundaram Sankara Subba Babinski, M. Marinho, M. M. Barbosa, J .S. F. Sato, I. M. Salvador, V. L. |
Abstract: | Lead–lead isotope data from whole rock samples are used to investigate the recent (last few million years) mobility of U and Th. The method is based on the comparison of the calculated present day U and Th concentrations required to yield the Pb isotope composition in the samples with the actual present day concentrations of U and Th obtained by direct measurement. The geological formations studied include the Neoproterozoic carbonate sediments of the Bambuı́ Group, Archean/Paleoproterozoic granite–greenstone terrain of the Contendas–Mirante Complex and a Proterozoic ortho-gneisses hosting U deposit in Lagoa Real. All these formations are in the São Francisco Craton, Brazil. The data show high U mobility in the carbonate sediments and in the deformed ortho-gneisses set in a ductile shear zone. Infiltration of groundwater through fault zones seems to have facilitated the U mobility. The Pb isotope approach is a useful technique complementing U-series disequilibrium studies and may be included for site characterization studies for radioactive waste disposal. |
URI: | http://www.repositorio.ufba.br/ri/handle/ri/7658 |
Issue Date: | Mar-1999 |
Appears in Collections: | Artigo Publicado em Periódico (IGEO) |
Files in This Item:
File | Description | Size | Format | |
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Marinho.pdf Restricted Access | 609,38 kB | Adobe PDF | View/Open Request a copy |
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