Uluru from wikipedia

Uluru is an inselberg, literally "island mountain".[6][7][8] An inselberg is a prominent isolated residual knob or hill that rises abruptly from and is surrounded by extensive and relatively flat erosion lowlands in a hot, dry region.[9] Uluru is also often referred to as a monolith, although this is a somewhat ambiguous term that is generally avoided by geologists.[10]

The remarkable feature of Uluru is its homogeneity and lack of jointing and parting at bedding surfaces, leading to the lack of development of scree slopes and soil. These characteristics led to its survival, while the surrounding rocks were eroded.[10]

For the purpose of mapping and describing the geological history of the area, geologists refer to the rock strata making up Uluru as the Mutitjulu Arkose, and it is one of many sedimentary formations filling the Amadeus Basin.[6]