layer - a relatively thin sheetlike expanse or region lying over or under another

asthenosphere - the lower layer of the crust

horst - a ridge of the earth's crust that has been forced upward between two faults and so is higher than the surrounding land

geosphere, lithosphere - the solid part of the earth consisting of the crust and outer mantle

crustal plate, plate - a rigid layer of the Earth's crust that is believed to drift slowly

sial - the granite-like rocks that form the outermost layer of the earth's crust; rich in silicon and aluminum

sima - rock that form the continuous lower layer of the earth's crust; rich in silicon and magnesium

covering, natural covering, cover - a natural object that covers or envelops; "under a covering of dust"; "the fox was flushed from its cover"

calculus, tophus, tartar - an incrustation that forms on the teeth and gums

rudeness, discourtesy - a manner that is rude and insulting

chutzpa, chutzpah, hutzpah - (Yiddish) unbelievable gall; insolence; audacity

change surface - undergo or cause to undergo a change in the surface