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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Uranium series disequilibria in ground waters from a fractured bedrock aquifer (Morungaba Granitoids-Southern Brazil): Implications to the hydrochemical behavior of dissolved U and Ra

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Author(s):
Reyes, Erika [1] ; Marques, Leila S. [1]
Total Authors: 2
Affiliation:
[1] Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer, Dept Geofis, BR-05508090 Sao Paulo - Brazil
Total Affiliations: 1
Document type: Journal article
Source: Applied Radiation and Isotopes; v. 66, n. 10, p. 1531-1542, OCT 2008.
Web of Science Citations: 5
Abstract

Activity concentrations of dissolved U-234, U-238, Ra-226 and Ra-228 were determined in ground waters fromtwo deep wells drilled in Morungaba Granitoids (Southern Brazil). Sampling was done monthly for little longer than 1 year. Significant disequilibrium between U-238, U-234 and Ra-226 were observed in all samples. The variation of U-238 and U-234 activity concentrations and U-234/U-238 activity ratios is related to seasonal changes. Although the distance between the two wells is short (about 900m), systematic differences of activity concentrations of U isotopes, as well as of U-234/U-238, Ra-226/U-234 and Ra-228/Ra-226 activity ratios were noticed, indicating distinct host rock-water interactions. Slightly acidic ground water percolation through heterogeneous host rock, associated with different recharge processes, may explain uranium and radium isotope behavior. (c) 2008 Elsevier Ltd. All rights reserved. (AU)