Artigo de Periódico
The chemistry of some Brazilian soils: Element mobility during intense weathering
Fecha
1979Registro en:
0009-2541
v. 24, n. 3–4
Autor
Kronberg, B. I.
Fyfe, W. S.
Leonardos Junior, O. H.
Santos, A. M.
Kronberg, B. I.
Fyfe, W. S.
Leonardos Junior, O. H.
Santos, A. M.
Institución
Resumen
Chemical data for 56 elements in soils from three regions of Brazil (Bahia, Amazon,
Goias) indicate that intense chemical weathering leads to a product soil essentially in the
system, SiO~--AI20 ~ --F%O3--H~O. The major minerals of the leached soils are quartz, kaoli
nite, gibbsite, goethite and hematite.
Trace elements show a wide range of behaviour from those which are enriched as for
some bio-important elements (B, C1, Mo, Se, Sn, I) and refractory metals (Sc, Zr, Nb, Gd,
Tm, Th) to the majority which are severely leached. Trace-element behaviour appears to
be largely controlled by the dominant clay or AI303--SiO 2 minerals, or the degree of
weathering.
Consideration of the chemistry of lateritic soils and groundwaters indicates that the
development of deep lateritic profiles requires times in the order of tens of millions of
years in a very stable continental setting.