U-ages in soils and groundwater evidencing wet periods 400-600 kyr ago in southeast Brazil
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Data
2007-07-01
Autores
Bonotto, Daniel Marcos [UNESP]
Jimenez-Rueda, J. R.
Título da Revista
ISSN da Revista
Título de Volume
Editor
Elsevier B.V.
Resumo
U-238 and its radiogenic daughter U-234 have been utilized for dating soil formation and groundwater residence time during the last 1.5 million years, in this case based on the U-clissolution/precipitation occurring during modifications of the oxidation-reduction conditions. In this paper, we report a 400-600 kyr proxy of wet periods from sediments occurring in a soil profile developed over rocks outcropping at the Parana sedimentary basin in Brazil, and from groundwater exploited of Guarani aquifer at the same basin. The approaches indicated successful use of the U-modeled ages for suggesting wet periods exceeding the past 116-210 kyr from previous studies. (C) 2007 Elsevier Ltd. All rights reserved.
Descrição
Palavras-chave
uranium isotopes, groundwater, Guarani aquifer, soils, Parana sedimentary basin
Como citar
Applied Radiation and Isotopes. Oxford: Pergamon-Elsevier B.V., v. 65, n. 7, p. 776-783, 2007.