Are The Continents Composed Mostly Of Granitic Rock Or Basaltic. Basaltic rocks of the ocean plates are much denser and heavier than the granitic rock of the continental plates. The crust is composed of two basic rock types granite and basalt. The continental crust is composed mostly of granite.
Continental crust is broadly granitic in composition and with a density of about 2 7 grams per cubic cm is somewhat lighter than oceanic crust which is basaltic i e richer in iron and magnesium than granite in composition and has a density of about 2 9 to 3 grams per cubic cm. Earth contains three kinds of rocks namely igneous rocks sedimentary rocks and metamorphic rocks basalt and granite are two types of igneous rocks.
All rocks of igneous origin consist of magma or molten earth that finds its way up to.
This difference in density allows the continents to float higher on the underlying mantle. This difference in density allows the continents to float higher on the underlying mantle. The continental crust is composed mostly of granite. Some of it erupts on land too but to a first approximation basalt is an oceanic rock.
