Use of U-isotope disequilibrium to evaluate the weathering rate and fertilizer-derived uranium in São Paulo state, Brazil
The U-disequilibrium method was utilized to evaluate the velocity of alteration of rocks and fertilizer-derived uranium in the Corumbataí River basin, São Paulo state, Brazil. The Corumbataí River basin is affected by the continuous use of fertilizer-derived uranium utilized in sugar cane crops, inc...
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Published in | Environmental earth sciences Vol. 44; no. 4; pp. 408 - 418 |
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Main Authors | , |
Format | Journal Article |
Language | English |
Published |
Berlin
Springer
01.07.2003
Springer Nature B.V |
Subjects | |
Online Access | Get full text |
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Summary: | The U-disequilibrium method was utilized to evaluate the velocity of alteration of rocks and fertilizer-derived uranium in the Corumbataí River basin, São Paulo state, Brazil. The Corumbataí River basin is affected by the continuous use of fertilizer-derived uranium utilized in sugar cane crops, increasing the dissolved uranium concentration in the Corumbataí River (Santa Terezinha station) in the wet period to 43%. The weathering rate in the Corumbataí River basin utilizing the U-isotope modeling was 0.0265 mm/year (corresponding to 38,000 years to weather 1 m of rock under actual climatic conditions). However, when the inputs of anthropogenic uranium were considered, then a weathering rate of 0.022 mm/year (corresponding to 45,500 years to weather 1 m of rock) was determined. The removed material in the Corumbataí River basin is mainly from two sub-basins (the Cabeças River and Passa Cinco River), where the sandstones weather easier than the siltstones and claystones in the basin.[PUBLICATION ABSTRACT] |
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ISSN: | 0943-0105 1866-6280 1432-0495 1866-6299 |
DOI: | 10.1007/s00254-003-0775-4 |