ABSTRACT
This chapter examines the geomorphological relationships, palaeoclimatic significance and mechanisms of duricrust formation. Beneath the hardpan layer duricrusts display a variety of material types. Ferricretes, for example, often have rather erodible pallid and mottled horizons grading down into more or less coherent bedrock, while calcretes may be underlain by friable nodule horizons, and silcretes by kaolinitic clays. It is also important to realise that the geomorphological influence of duricrusts will depend to a considerable degree on the stage of evolution which the feature has reached. One consequence of the belief in the association of duricrusts and peneplains was the contention that upland or high-level laterites are essentially ‘dead’ and being eroded. Numerous workers have identified the role that duricrusts may play in relief inversion. In the case of laterite, laterite-covered valleys may become ridges or strings of mesas flanking lower, younger valleys, and pediments may become mesas.
