Mineralogy and granulometry of three latosols from the region of the middle São Francisco River, BA

Abstract

The granulometry and mineralogy of the sand fraction of 3 soils classified as Red Yellow Latosol from the region of middle São Francisco River, Ba, Brazil, were estudied. The statistical parameters proposed by FOLK and WARD (1957) were employed for the granulometry studies; for the mineralogy studies, the heavy residual of the 250 to 50 µ fraction was utilized. The soils showed high homogeneity as to granulometry with moderately selected material, the fine fractions being predominant. Mineralogically, they are of high maturity, with highly stable minerals, which have undergone several sedimentation cycles. The distribution of the heavy minerals in the profiles suggests litological discontinuities.