The development of a red-brown earth. II. Uniformity of the parent material

Abstract

Five criteria based on the particle-size distribution of resistant minerals in the non-clay fraction and the ratio of two resistant minerals in the 5-125 µm fraction were applied to establish the uniformity of the parent material of the Urrbrae loam (a Rhodoxeralf). It was concluded that the parent material of the Urrbrae loam was uniform and that there was no basis for the hypothesis that A and B horizons had a separate sedimentary origin. The validity of assigning elemental percentages to specific resistant minerals was confirmed following analysis of the light mineral fraction (<2.96 g cm-3) for zirconium, yttrium, titanium and phosphorus, and finding that there was only a minor amount of these elements present.