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
Barak (given name) Barak (given name) The given name Barak, also spelled Baraq, from the root "B-R-Q", is a Hebrew name meaning "lightning". It appears in the Hebrew Bible as the name of Barak ( ""), an Israelite general. It is also an Arabic name from the root "B-R-K" with the meaning of "blessed" though it is mostly in its feminine form "Baraka(h)". The Semitic root "B-R-Q" has the meaning "to shine"; "lightning". The biblical name " is given after Barak, a military commander who appears in the Book of Judges. The Arabic cognate is ' (not to be confused with ', which