Soils derived from granite in two Mt. Garnet toposequences, North Queensland, Australia

Abstract

Two toposequences derived from granite in the Mt. Garnet area, North Queensland, were examined to determine the detailed soil - landform relationships in order to facilitate subsequent broad-scale mapping of the soil resource. The dominant landsurface feature is gently sloping, concave footslopes covered by relatively thick colluvial deposits. It is assumed that these footslopes are attributable to a retreating midslope as well as the colluviation of materials during dry periods of the Late Mid- to End-Pleistocene. Granulometrie parameters indicated a single source of parent material for the footslope soils, although there would seem to be a temporal discontinuity between the A and B horizons. The distribution patterns of the footslope soils (varying from Griffin, Shepstone to Longlands forms) could be explained by means of a simple catenary model, in which profile hydrology, caused by a water surplus generated by the physical environment, played the major role. In extent, the footslope is dominated by th...