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| 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. |
| 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... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Magnetite; Maghemite; Trace elements; Mafic rocks; Raman spectroscopy. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832019000100411 |
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| Camêlo,Danilo de Lima; Ker,João Carlos; Fontes,Maurício Paulo Ferreira; Corrêa,Marcelo Metri; Costa,Antonio Carlos Saraiva da; Melo,Vander Freitas. |
| ABSTRACT Despite the considerable amount of information on the mineralogical characteristics of pedogenic Fe oxides in Brazilian soils, there are few studies on Fe-rich soils developed from mafic rocks with taxonomic identities at lower categorical levels. This study evaluated the mineralogical characteristics of pedogenic Fe oxides in B horizons (Bw) of Fe-rich Oxisols developed from several mafic rocks in the state of Minas Gerais, Brazil. The Bw horizons were sampled at a 0.8-1.0 m depth in 13 Ferric and Perferric Rhodic Oxisols along with a Mesoferric Typic Oxisol originating from basalt, gabbro, tuffite, amphibolite and itabirite in Minas Gerais. The selected soils have taxonomic identities up to the fourth categorical level of the Brazilian System of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Hematite; Maghemite; Crystallographic characteristics; Al-substitution; Selective dissolution. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832017000100413 |
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| Inda,Alberto Vasconcellos; Torrent,José; Barrón,Vidal; Bayer,Cimélio; Fink,Jessé Rodrigo. |
| Replacing conventional tillage (CT) with no-tillage (NT) management alters the pedoenvironment and the rate of topsoil processes, with possible effects on dissolution processes associated with iron oxides and therefore soil mineralogy. This study aimed to determine the effect of NT on the content and distribution of types of iron oxides in a Rhodic Paleudult in southern Brazil. Soil samples were collected at eight depths within the 0.00-0.80 m layer under CT and NT in a long-term experiment (21 years). Mineralogical identification was conducted by X-ray diffraction (XRD), and the Fe content related to specific types of iron oxides determined by selective dissolution and diffuse-reflectance spectroscopy. Kaolinite, quartz, goethite, hematite, and maghemite... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Dissolution; Ferrihydrite; Hematite; Maghemite; Soil management. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162013000100008 |
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