Uluru inselberg

Uluru (Pitjantjatjara: Uluru, also known as Ayers Rock (Sweet and Crick, 1994; Twidale and Bourne, 2012), is a large sandstone formation in the centre of Australia. It is in the southern part of the arid Northern Territory. Uluru, a massive inselberg or ‘island mountain’ of bedded sandstone referred to the Mutitjulu Arkose, is a prominent isolated residual knob that rises abruptly from and surrounded by extensive flat lowlands. The remarkable feature of Uluru is its lack of jointing and parting at bedding surfaces, leading to the lack of scree slopes and soil (Figures 2 and 3). Uluru is dominantly composed of coarse-grained arkose (a sandstone characterised by abundant feldspar) and some conglomerate, and is Precambrian, some 550 million years old. The minerals present suggest derivation predominantly from a granite source. Weathering of iron-bearing minerals gives the outer surface layer of rock a red-brown rusty colour. Sedimentary features within the sandstone include cross-bedding and ripples, analysis of which indicates deposition from broad shallow high energy fluvial channels and sheet flooding (Young et al., 2002).