Uluru (Ayers Rock) and Kata Tjuta (The Olgas): Inselbergs of Central Australia

Uluru and Kata Tjuta are inselbergs standing in isolation in the desert plains of central Australia. Uluru is a beveled bornhardt shaped steeply dipping Cambrian arkose. Kata Tjuta is a complex of domes, each developed by fracture-controlled weathering and erosion of a mass of gently dipping conglomerate, also of Cambrian age. The sedimentary formations strike northwest to southeast and the compartments on which the residuals are formed were compressed as a result of either cross- or interference folding. They were exposed as low hills by the latest Cretaceous and possibly as early as the Triassic, since which time the detailed morphology of the forms shows that they have come to stand higher and higher in the relief as a result of the episodic lowering of the surrounding plains. Their persistence is attributed to reinforcement effects.C. R. Twidalehttp://www.springer.com/earth+sciences+and+geography/geography/book/978-90-481-3054-

Is Australia a tectonically stable continent? Analysis of a myth and suggested morphological evidence of tectonism

Occasional references to the relative tectonic instability of the Australian continent have been published over the last hundred years or so. Youthful tectonic forms were described from various parts of the continent throughout that period. Despite this, it was repeatedly claimed that the shield lands in particular were tectonically stable, and as recently as this century reference has been made to a concept embracing a tectonically inert continent. However, some 60 years ago, the accumulated evidence convinced E.S. Hills that in Australia all land surfaces, including the shield lands, and even recent alluvial plains, were tectonically disturbed. This conclusion was reinforced by analyses of seismicity and faulting; by regional geological mapping that revealed widely distributed tectonic forms and especially fault-related features, many of them of neotectonic age; by technological advances that allow faulting episodes to be closely dated; by the recognition of underprinting; and by the realization that many minor forms, previously unrecognized or attributed to other mechanisms or processes, are associated with crustal stress and are of tectonic origin. Thus, while Australia is a relatively stable continent, it is subject to widespread small-magnitude earth movements. Ironically, in view of earlier thinking, neotectonic forms may be better developed and preserved on the shields than elsewhere.C. R. Twidal