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

Abstract

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.