A bornhardt is a dome-shaped, steep-sided, bald rock outcropping at least in height and several hundred metres in width. A type of inselberg, bornhardts are typically composed of granites or gneisses, though occasionally formed in other rock types such as dacite, norite, limestone, sandstone and conglomerate. Uluru, in Central Australia, is mainly composed of sandstones, while the nearby Kata Tjuta is composed of conglomerates. They are named after Wilhelm Bornhardt (1864–1946), a German geologist and explorer of German East Africa, who first described the feature. The Sugarloaf Mountain of Rio de Janeiro is a typical example of this landform and is the origin of the common bornhardt nickname "sugar loaf".