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
Adam (given name) Adam (given name) Adam is a common masculine given name. The personal name "Adam" derives from the Hebrew noun "ha adamah" meaning "the ground" or "earth". Its Quranic and Biblical usage has ensured that it is also a common name in all countries which draw on these traditions. It is particularly common in Christian and Muslim majority countries. In most languages its spelling is the same, although the pronunciation varies somewhat. Adán is the Spanish form of this name. Adam is also a surname in many countries, although it is not as common in English as its derivative Adams (sometimes