Produção Nacional
Iron oxides in two Oxisols from the Brazilian coastal plain
1985; Wiley; Volume: 36; Issue: 4 Linguagem: Inglês
10.1111/j.1365-2389.1985.tb00357.x
ISSN2056-5240
AutoresJosé Domingos Fabris, Mauro Resende, E. Galvao Da Silva, J. M. D. Coey,
Tópico(s)Geochemistry and Elemental Analysis
ResumoSUMMARY Two Oxisols from the B2 horizon at similar locations 2 km apart on the Brazilian coastal plain with a udic, isohyperthermic regime were practically identical in chemical composition but differed markedly in colour; one was a dark reddish brown, the other a pale ochre. Mossbauer spectra at 295 K, 80 K and 4.2 K indicated a clear difference in iron oxide mineralogy. Iron was present as aluminous hematite and goethite, with Al substitutions of approximately 20% in the two phases. However, the relative proportion of iron present in hematite and goethite was 45:55 in the first sample and 12:88 in the second. Possible reasons for these differences are discussed.
Referência(s)