craton

A craton (Greek kratos / κρἀτος (neut.) "strength") is an old and stable part of the continental lithosphere. Cratons have often survived cycles of merging and rifting of continents are generally found in the interiors of tectonic plates. They are characteristically composed of ancient crystalline basement rock, which may be covered by younger sedimentary rock. They have a thick crust and deep lithospheric roots that extend up to a few hundred kilometers into the Earth's mantle.