Are The Continents Composed Mostly Of Granitic Rock Or Basaltic

Earth contains three kinds of rocks namely igneous rocks sedimentary rocks and metamorphic rocks basalt and granite are two types of igneous rocks.

Are the continents composed mostly of granitic rock or basaltic.

This difference in density allows the continents to float higher on the underlying mantle. The crust is composed of two basic rock types granite and basalt. The oceanic crust consists of a volcanic lava rock called basalt. Some of it erupts on land too but to a first approximation basalt is an oceanic rock.

While the ocean basins are composed of mostly basaltic rocks with an average density of 3 0g cm 3. Basalt is the dark heavy volcanic rock that makes up most of the world s oceanic crust. Compared to the familiar granite of the continents basalt ba salt is darker denser and finer grained. All rocks of igneous origin consist of magma or molten earth that finds its way up to.

Continental crust is typically 40 km 25 miles thick while oceanic crust is much thinner. The continental crust is composed mostly of granite. Basaltic rocks of the ocean plates are much denser and heavier than the granitic rock of the continental plates. 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.

Why are continents made mostly of granitic rocks and ocean basins mostly of basaltic rocks.