Data/hora: 11/06/2024 08:10:41

Provedor de dados: | 90
País: | Brazil
Título: | Mineralogical Evolution of Magnetic Rhodic Oxisols under Different Lithological Influences in Brazil
Autores: | Silva Filho,Luiz Aníbal; Ker,João Carlos; Fontes,Maurício Paulo Ferreira; Camêlo,Danilo de Lima; Corrêa,Marcelo Metri; Cavalcante,Luis Carlos Duarte; Guimarães,Luciano de Moura.
Data: | 2019-01-01
Ano: | 2019
Palavras-chave: | Magnetite; Maghemite; Trace elements; Mafic rocks; Raman spectroscopy.
Resumo: | ABSTRACT Ferrimagnetic Fe-oxides are important soil components, which are present in most of the agricultural soils of Brazil. Distinction, origin, and assessment of the influence of these minerals on magnetism and geochemistry is a challenge for mineralogists. This study aimed to characterize mineralogically Fe-rich Rhodic Oxisols ( Latossolos Vermelhos ) originating from several mafic rocks in Brazil, and assess the implications on their magnetic and geochemical properties. We present results on magnetic measurements, chemical dissolutions, X-ray diffractometry, Rietveld refinement, Raman, and Mössbauer spectroscopies of Fe-rich Rhodic Oxisols originating from several mafic rocks. They show that magnetite is inherited from the parent material, and its oxidation leads to the formation of maghemite. In the coarse fractions (sand and silt), magnetite and maghemite coexist and are interstratified with hematite, confirmed by Raman spectroscopy. This limited the distinction between magnetite and maghemite by Mössbauer spectroscopy. Maghemite represents the only ferrimagnetic Fe oxide in the clay fraction. The influence of both ferrimagnetic minerals, magnetite and maghemite, on magnetic susceptibility and total content of trace elements is determined by the pedogenic development, even among highly weathered soils. In general, the coarse fractions contribute with most of the total trace element contents, while the clay fraction contributes to trace elements availability and magnetic susceptibility of soils.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832019000100411
Editor: | Sociedade Brasileira de Ciência do Solo
Relação: | 10.1590/18069657rbcs20190065
Formato: | text/html
Fonte: | Revista Brasileira de Ciência do Solo  v.43 2019
Fonte: | info:eu-repo/semantics/openAccess