Artigo Produção Nacional Revisado por pares

Some geological characteristics in a regolith-limey shale rock profile through natural radionuclides distribution

2010; Elsevier BV; Volume: 68; Issue: 9 Linguagem: Inglês

10.1016/j.apradiso.2010.03.005

ISSN

1872-9800

Autores

Ademar de Oliveira Ferreira, Rodrigo Oliveira Bastos, Carlos Roberto Appoloni,

Tópico(s)

Radioactive contamination and transfer

Resumo

The objective of this work is to study some geological characteristics in a regolith-rock profile by analyzing the distribution of natural radionuclides along the profile by high resolution gamma ray spectrometry. The concentrations of radionuclides reflect some mineralogical characteristics of the rock matrix and also more recent events, such as weathering and erosion. The samples were collected in an abandoned limestone mine, in the city of Sapopema, Paraná State, Brazil. The stratigraphy is represented by an alternation of decimetric limestone layers, bituminous shale and some rhythmite layers. The ratios eTh/K obtained for all samples of the studied profile have equivalent values, indicating similar mineralogical characteristics of their detritic components. The ratio eTh/eU corroborates the fact that regolith samples belong to a much more oxidized environment, favoring the leaching of uranium. These results show that the measurement of radionuclide distribution in rocks and soils may be an important tool for the analysis of geological characteristics, such as mineralogy and oxidizing conditions.

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