The Influence of Deep Weathering on Coastal Landscape and Landform Development in the Monsoonal Tropics of Northern Australia

Abstract

The role of sub-aerial processes in the development of coastal configurations and related rock landforms in tropical regions has in the past been largely ignored. Formation of the Darwin coast and environs in the seasonally dry tropics of northern Australia has been strongly influenced by deep weathering processes. Substantial lengths of this coast have derived their present configurations as a result of the style of land surface lowering and weathering processes operating here. Individual landforms such as shore platforms and offshore rocky reefs also owe their origins largely to the same cause. While marine processes cannot be overlooked, the origin of rocky coasts and their landforms in tropical cratons with highly weatherable substrates is best sought in the landscape evolution of the coastal hinterland. A previously unrecognized style of etchplanation, here called land surface refraction, involves subsurface structural and lithological controls that influence surface topography and explains the development of many coastal landforms.