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
Ruby (given name) Ruby (given name) Ruby is a predominantly feminine given name taken from the name of the gemstone ruby. The name of the gemstone comes from the Latin "ruber", meaning "red". The ruby is the birthstone for the month of July. The name first came into wide use for girls in the late Victorian era along with other jewel names. Ruby is a currently popular name in English-speaking countries. It was the second most popular name given to baby girls in England and Wales in 2009, was the 24th most popular name given to baby girls born in Scotland in 2009;