Evolution of the Australian landscape

Abstract

Landscape evolution of Australia is on the same time scale as global tectonics and biological evolution. In places, actual landforms and deep weathering products are hundreds of millions of years old. Much of Australia has a landscape resulting from stripping of weathered rock after an earlier period of very deep weathering. Other regions have sequential landforms that provide a natural laboratory where we can work out the biogeochemistry of the past. Landforms and regolith reveal the long evolution of groundwater in Australia. Lateral movement of groundwater is of paramount importance. The effects of past climates are stored in the landscape. They show that the present is not the key to the past, and former environments must be worked out from consistent internal evidence rather than the application of models based on present-day conditions. Inorganic chemistry alone is inadequate to explain many earth materials, and biology, especially microbiology, has a very significant role. Recent and present-day processes also affect the landscape, and it cannot be assumed that because the landscape and regolith are old the soils are old. Many regions have a complex regolith cover that shows modern processes working on inherited materials.