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Sm-Nd system in total rock open versus closed isotopic composition in zones of high deformation
(2002-12-01)
High strain shear zones of Brasiliano age, developed in Paleoproterozoic basement gneiss of the Caicó region, Borborema Province, NE Brazil, were associated with medium- to low-grade metamorphism and deformational processes ...
Some constraints on the modelling using the uranium isotopes 238U and 234U for dating groundwaters from Guarany aquifer, South America
(2000-12-01)
Groundwaters from the Guarany aquifer located at the South American continent and sampled at four wells with described geological sections in São Paulo State, Brazil, were chemically and isotopically analysed with two aims: ...
The application of U-isotopes to assess weathering in contrasted soil-water regime in Brazil
(2018-02-01)
This paper presents the use of U-series radionuclides 238U and 234U to evaluate the biogeochemical disequilibrium in soil cover under a contrasted soil-water regime. The approach was applied in three profiles located in ...
Weathering processes and dating of soil profiles from São Paulo State, Brazil, by U-isotopes disequilibria
(2017-01-01)
This study reports the use of the U-series radionuclides 238U and 234U for dating two soil profiles. The soil horizons developed over sandstones from Tatuí and Pirambóia formations at the Paraná sedimentary basin, São Paulo ...
Groundwater isotope ratios reflect convective and stratiform (paleo)precipitation fractions in Brazil
(2020-06-01)
The stable isotope ratios of oxygen and hydrogen in shallow groundwater reflect the long-term amount-weighted mean isotopic composition of precipitation. Here, we report the isotopic composition of more than 1000 shallow ...