Aspects of the distribution and disintegration of siliceous duricrusts in arid Australia

Abstract

Topographic, chronologic and climatic implications of siliceous duricrusts that are widely developed and preserved in inland arid Australia are discussed. Plateaux capped by siliceous duricrusts are characteristic, but are probably manifestations of large-scale relief inversion. Such duricrusts have been widely used as morphostratigraphic markers, and despite many possible difficulties, these interpretations may well be valid; but caution and consideration of the local evidence are necessary. The climatic context of silcrete both from the viewpoint of its formation and its degradation is uncertain. It may be that the various solutional features developed on these siliceous materials offer evidence on this point complementary to that derived from stratigraphic studies.