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
Emmy (given name) Emmy (given name) Emmy is a feminine (sometimes also masculine) given name. Orthographic variants include Emme, Emmi and Emmie. The name is in many instances a hypocoristic of either Emma (itself being in origin a hypocoristic of a number of ancient Germanic names beginning in "ermen") or (more rarely) Emily, or Emmanuel (Emmanuelle). It came to be used as a separate (rare) German name, given officially in Germany from the later 19th century. As an officially given feminine name, Emmy ranked 66th in Sweden and 89th in France as of 2010. Emmy is rarely also encountered as a surname. Notable