Crust (geology) crustal rocks formed before 2.5 billion years ago are located in cratons. Such old continental crust and the underlying mantle asthenosphere are less dense than elsewhere in Earth and so are not readily destroyed by subduction. Formation of new continental crust is linked to periods of intense orogeny; these periods coincide with the formation of the supercontinents such as Rodinia, Pangaea and Gondwana. The crust forms in part by aggregation of island arcs including granite and metamorphic fold belts, and it is preserved in part by depletion of the underlying mantle to form buoyant lithospheric mantle. A theoretical protoplanet named
Aonghas (given name) Aonghas (given name) Aonghas is a masculine given name in Scottish Gaelic. It is composed of Celtic elements meaning "one", and "choice". A variant spelling of the Scottish Gaelic name is "Aonghus". The Irish form of the Scottish Gaelic names is "Aengus". A pet form of the Scottish Gaelic name is "Angaidh", which is represented in English as "Angie", pronounced ""an-ghee"". The earliest form of the given name "Angus", and its cognates, occurs in Adomnán's "Vita Columbae" (English: ""Life of Columba"") as "Oinogusius", "Oinogussius". This name likely refers to a Pictish king whose name is recorded variously as "Onnust", "Hungus".