Landforms of Kakadu Stone Country
It is believed that 140 million years ago much of Kakadu was under a shallow sea. The prominent escarpment wall formed sea cliffs and the Arnhem Land plateau formed a flat land above the sea. Today the escarpment, which rises to 330 metres above the plains, extends over 500 kilometres along the eastern boundary of the park. It varies from vertical cliffs in the Jim Jim Falls area to stepped cliffs and isolated outliers in the north.
The rock platforms of the plateau are dissected by a network of chasms and gorges. The top of the plateau is a harsh, dry place. Water drains away quickly. In most areas soil is scarce. The small patches of soil that are to be found consist mostly of coarse sand and leaf litter trapped in rock fissures or shallow depressions. Sparsely distributed pockets of woodland and open forest have developed on these coarse soils.
Along the escarpment, creeks have etched deep incisions to form gorges in which tall monsoon forests have developed. Water seeping from rock walls and the deep alluvial soils provide an important micro-environment for plants and animals. Many animals rely on these areas for refuge during the drier months. The dominant plant species is Allosyncarpia ternata, a large, spreading, shady tree that is found only in the Kakadu and Arnhem Land region.
Typical examples of Kakadu's stone country can be seen from the Gunlom lookout walk and at Maguk and Jim Jim and Twin Falls.