info:eu-repo/semantics/article
Two loess formations of upper quaternary age in the brazilian nordeste
Fecha
2010-06Registro en:
Iriondo, Martin Horacio; Brunetto, Ernesto; Two loess formations of upper quaternary age in the brazilian nordeste; E Schweizerbartsche Verlags; Zeitschrift Fur Geomorphologie; 54; 2; 6-2010; 253-265
0372-8854
CONICET Digital
CONICET
Autor
Iriondo, Martin Horacio
Brunetto, Ernesto
Resumen
Two sedimentary formations of eolian origin, composed of silt and loamy silt occur in the interior of the Brazilian Nordeste, several hundred kilometers to the west of the coast (fig. 1). The area is semiarid, dominated by the trade winds and prone to severe droughts under the present climate. Climatic conditions not very different to the present ones are postulated for the times of origin of both units. The older one is the Cariutaba Formation, red in colour, massive, friable, porous and loose. Absolute ages from 21 ky BP to 8.5 ky BP were obtained by TL methods. The younger loess is gray in colour, powderish, loose and underwent subfussion processes (piping). Late Holocene ages of ca. 2.60 to 2.20 ky BP were found in this unit.