Development and distribution of soils in the Merredin area, Western Australia

Abstract

The soil pattern in the Merredin district of Western Australia is closely related to a number of readily recognizable landscape features. An understanding of these relationships is proving useful in broad-scale mapping in semi-arid Western Australia and the units so obtained can be readily subdivided for more detailed mapping. Soil and topographic relationships of the five surfaces recognized are described in detail. These are an expression of erosional modifications of a mature Tertiary landscape resulting from changes in landscape stability. Deep lateritic weathering has influenced the chemistry and morphology of large areas of soils. Smaller areas of soils are developed from less weathered material exposed by complete removal of the lateritic profile, and from lake parna resulting from wind deflation of salinized alluvial sediments. The physical and chemical properties of samples from representative soils are summarized and discussed with reference to profiles which are arranged in groups on the basis of origin of parent material.